WEBVTT 00:02.600 --> 00:04.933 align:left position:25%,start line:5% size:65% - Welcome everyone to Wednesday Nite @ the Lab. 00:05.033 --> 00:06.366 align:left position:32.5%,start line:5% size:57.5% I'm Tom Zinnen. 00:06.466 --> 00:09.366 align:left position:15%,start line:5% size:75% I work here at the UW-Madison Biotechnology Center. 00:09.466 --> 00:12.833 align:left position:15%,start line:5% size:75% I also work for the Division of Extension Wisconsin 4-H. 00:12.933 --> 00:15.733 align:left position:15%,start line:71% size:75% And on behalf of those folks and our other co-organizers, 00:15.833 --> 00:19.433 align:left position:15%,start line:71% size:75% PBS Wisconsin, the Wisconsin Alumni Association, 00:19.533 --> 00:21.966 align:left position:27.5%,start line:71% size:62.5% and the UW-Madison Science Alliance, 00:22.066 --> 00:24.633 align:left position:17.5%,start line:71% size:72.5% thanks again for coming to Wednesday Nite @ the Lab. 00:24.733 --> 00:28.400 align:left position:17.5%,start line:71% size:72.5% We do this every Wednesday night, 50 times a year. 00:28.500 --> 00:32.266 align:left position:15%,start line:71% size:75% Tonight, it's my pleasure to introduce to you Haley Vlach. 00:32.366 --> 00:33.566 align:left position:22.5%,start line:71% size:67.5% She's a professor here 00:33.666 --> 00:36.200 align:left position:25%,start line:71% size:65% in the Department of Educational Psychology 00:36.300 --> 00:38.666 align:left position:15%,start line:71% size:75% and our School of Education. 00:38.766 --> 00:41.066 align:left position:32.5%,start line:71% size:57.5% She was born in Portland, Oregon, 00:41.166 --> 00:43.766 align:left position:17.5%,start line:71% size:72.5% and went to high school at Mountain View High School 00:43.866 --> 00:45.733 align:left position:30%,start line:71% size:60% in Bend, Oregon. 00:45.833 --> 00:47.733 align:left position:25%,start line:71% size:65% And then she went to Carnegie Mellon University 00:47.833 --> 00:50.400 align:left position:20%,start line:71% size:70% in Pittsburgh and studied business administration 00:50.500 --> 00:52.166 align:left position:32.5%,start line:71% size:57.5% and psychology. 00:52.266 --> 00:53.433 align:left position:20%,start line:71% size:70% Then she moved back west 00:53.533 --> 00:56.066 align:left position:17.5%,start line:71% size:72.5% to go to the University of California at Los Angeles 00:57.066 --> 01:01.866 align:left position:10%,start line:71% size:80% for her master's degree and PhD, both of which in psychology. 01:01.966 --> 01:04.600 align:left position:25%,start line:71% size:65% Tonight, she's going to be talking with us 01:04.700 --> 01:07.200 align:left position:15%,start line:71% size:75% about forgetting, what it is, 01:08.900 --> 01:10.933 align:left position:15%,start line:71% size:75% and how it helps us remember. 01:12.366 --> 01:15.966 align:left position:20%,start line:71% size:70% Pretty fascinating topic, a paradox. 01:16.066 --> 01:19.100 align:left position:30%,start line:71% size:60% Please join me in welcoming Haley Vlach 01:19.200 --> 01:20.833 align:left position:15%,start line:71% size:75% to Wednesday Nite @ the Lab. 01:21.833 --> 01:23.366 align:left position:12.5%,start line:71% size:77.5% - Thanks for that introduction. 01:23.466 --> 01:25.833 align:left position:17.5%,start line:71% size:72.5% I'm very excited to be here 01:25.933 --> 01:28.633 align:left position:20%,start line:71% size:70% and to speak with you all about some of the work 01:28.733 --> 01:30.966 align:left position:10%,start line:71% size:80% that we've been doing in my lab. 01:31.066 --> 01:33.966 align:left position:15%,start line:71% size:75% I'm Director of the Learning Cognition and Development Lab. 01:34.066 --> 01:35.300 align:left position:32.5%,start line:71% size:57.5% And in my lab, 01:35.400 --> 01:38.566 align:left position:12.5%,start line:71% size:77.5% we're really interested in how people think and learn. 01:38.666 --> 01:40.666 align:left position:22.5%,start line:71% size:67.5% We spend a lot of time thinking and learning 01:40.766 --> 01:42.533 align:left position:15%,start line:71% size:75% about thinking and learning. 01:42.633 --> 01:43.766 align:left position:27.5%,start line:71% size:62.5% And in particular, 01:43.866 --> 01:46.100 align:left position:27.5%,start line:71% size:62.5% we're interested in cognitive development. 01:46.200 --> 01:50.266 align:left position:27.5%,start line:71% size:62.5%   That is, how does thinking change across the lifespan? 01:50.366 --> 01:52.633 align:left position:15%,start line:83% size:75% We're particularly interested in thinking and learning 01:52.733 --> 01:55.900 align:left position:20%,start line:83% size:70% during childhood, but we also study adults as well. 01:56.900 --> 01:59.500 align:left position:12.5%,start line:5% size:77.5% And we spend a lot of our time thinking about memory 01:59.600 --> 02:02.766 align:left position:17.5%,start line:5% size:72.5% and memory changes and how those changes in memory 02:02.866 --> 02:05.533 align:left position:22.5%,start line:5% size:67.5% might contribute to our thinking and learning. 02:06.666 --> 02:08.666 align:left position:30%,start line:71% size:60% And we're really interested in memory 02:08.766 --> 02:10.766 align:left position:20%,start line:71% size:70% for a number of reasons. 02:10.866 --> 02:12.166 align:left position:27.5%,start line:71% size:62.5% So the first reason 02:12.266 --> 02:14.733 align:left position:17.5%,start line:71% size:72.5% is that it's theoretically very interesting. 02:14.833 --> 02:17.400 align:left position:17.5%,start line:71% size:72.5% Like how does memory work? 02:17.500 --> 02:20.300 align:left position:22.5%,start line:71% size:67.5% We take in a seemingly infinite amount of information 02:20.400 --> 02:22.233 align:left position:32.5%,start line:71% size:57.5% from the world and somehow manage 02:22.333 --> 02:25.133 align:left position:32.5%,start line:71% size:57.5% to decode that information, store it, 02:25.233 --> 02:27.366 align:left position:25%,start line:71% size:65% and then retrieve it later when we need it. 02:27.466 --> 02:30.933 align:left position:27.5%,start line:71% size:62.5% And so that process is still a mystery 02:31.033 --> 02:33.566 align:left position:10%,start line:71% size:80% and is very motivating to study, 02:33.666 --> 02:36.566 align:left position:25%,start line:71% size:65% just coming up with a theory of how memory works. 02:37.566 --> 02:41.466 align:left position:12.5%,start line:71% size:77.5% Memory is also practically very important for many reasons. 02:41.566 --> 02:45.633 align:left position:17.5%,start line:71% size:72.5% So first, it's important to our day-to-day functioning. 02:45.733 --> 02:47.900 align:left position:17.5%,start line:71% size:72.5%   So for instance, when we're going to the grocery store, 02:48.000 --> 02:50.733 align:left position:12.5%,start line:83% size:77.5% we need to remember the things on our shopping list. 02:50.833 --> 02:54.366 align:left position:12.5%,start line:83% size:77.5% And we often think in our mind, "Hmm, do I need more milk?" 02:54.466 --> 02:56.066 align:left position:20%,start line:83% size:70% And you have to remember whether or not 02:56.166 --> 02:59.133 align:left position:25%,start line:83% size:65% you have milk in the fridge currently. 02:59.233 --> 03:02.000 align:left position:22.5%,start line:83% size:67.5% There's also many ways in which memory 03:02.100 --> 03:04.466 align:left position:15%,start line:89% size:75% can be implied into training, 03:04.566 --> 03:07.300 align:left position:32.5%,start line:83% size:57.5% educational and health interventions. 03:07.400 --> 03:10.633 align:left position:20%,start line:83% size:70% Memory is at the core of allowing us to think and learn, 03:10.733 --> 03:12.633 align:left position:12.5%,start line:89% size:77.5% as we will discuss more today. 03:12.733 --> 03:15.833 align:left position:30%,start line:83% size:60% And so there are numerous applications. 03:15.933 --> 03:18.666 align:left position:25%,start line:83% size:65% But on a more sort of spiritual or emotional level, 03:18.766 --> 03:22.533 align:left position:25%,start line:83% size:65% memory is fascinating because it's what defines us. 03:22.633 --> 03:25.566 align:left position:32.5%,start line:83% size:57.5% In other words, we are our memories. 03:25.666 --> 03:27.166 align:left position:32.5%,start line:83% size:57.5% When we create our sense of self, 03:27.266 --> 03:29.466 align:left position:25%,start line:83% size:65% we think back to all of our experiences, 03:29.566 --> 03:31.700 align:left position:12.5%,start line:89% size:77.5% and what those experiences are, 03:31.800 --> 03:34.900 align:left position:25%,start line:83% size:65% are the memories that we've stored in our brain. 03:35.000 --> 03:39.866 align:left position:22.5%,start line:83% size:67.5% So memory truly serves at the foundation of the self. 03:39.966 --> 03:42.666 align:left position:22.5%,start line:83% size:67.5% So there are many, many reasons to study memory. 03:44.366 --> 03:47.300 align:left position:30%,start line:71% size:60% One thing that is very interesting 03:47.400 --> 03:50.300 align:left position:12.5%,start line:71% size:77.5% to most people who are learning about memory for the first time 03:50.400 --> 03:53.866 align:left position:12.5%,start line:71% size:77.5% is that remembering is not the most common part of memory, 03:53.966 --> 03:57.300 align:left position:25%,start line:71% size:65% but instead the most ubiquitous process in memory 03:57.400 --> 03:59.433 align:left position:17.5%,start line:71% size:72.5% is the fact that we forget. 04:00.600 --> 04:03.833 align:left position:25%,start line:83% size:65% Today, what I'm going to do is I'm gonna first 04:03.933 --> 04:05.666 align:left position:27.5%,start line:83% size:62.5% provide an overview on forgetting. 04:05.766 --> 04:09.166 align:left position:22.5%,start line:83% size:67.5% What is it and what do we know about forgetting? 04:09.266 --> 04:10.566 align:left position:12.5%,start line:89% size:77.5% After that brief introduction, 04:10.666 --> 04:13.400 align:left position:25%,start line:83% size:65% we're gonna dive into talking about forgetting 04:13.500 --> 04:16.033 align:left position:25%,start line:89% size:65% helping us to learn. 04:16.133 --> 04:18.233 align:left position:15%,start line:83% size:75% And this is counterintuitive as we will discuss, 04:18.333 --> 04:20.166 align:left position:27.5%,start line:83% size:62.5% because normally we characterize forgetting 04:20.266 --> 04:22.766 align:left position:10%,start line:89% size:80% as a process that deters memory. 04:22.866 --> 04:25.666 align:left position:17.5%,start line:83% size:72.5% And then finally, I'll end with some concluding thoughts 04:25.766 --> 04:28.633 align:left position:15%,start line:83% size:75% about where we can go and how we can think about forgetting 04:28.733 --> 04:30.866 align:left position:20%,start line:89% size:70% in our day-to-day lives. 04:30.966 --> 04:32.466 align:left position:22.5%,start line:89% size:67.5% So first let's dive in, 04:32.566 --> 04:34.733 align:left position:30%,start line:83% size:60% let's talk about what forgetting is 04:34.833 --> 04:37.700 align:left position:27.5%,start line:83% size:62.5% and how scientists think about forgetting 04:37.800 --> 04:40.500 align:left position:22.5%,start line:83% size:67.5% when we study it from a scientific perspective. 04:41.500 --> 04:44.800 align:left position:17.5%,start line:5% size:72.5% Forgetting is operationally defined as the declining ability 04:44.900 --> 04:48.133 align:left position:22.5%,start line:5% size:67.5% to retrieve information across time. 04:48.233 --> 04:49.933 align:left position:25%,start line:5% size:65% And what you can see here in this image 04:50.033 --> 04:52.433 align:left position:20%,start line:5% size:70% is on the X-axis is time. 04:52.533 --> 04:54.833 align:left position:15%,start line:5% size:75% So number of days or a month, 04:54.933 --> 04:57.333 align:left position:22.5%,start line:5% size:67.5% and then on the Y-axis, you see this equation, 04:57.433 --> 05:00.566 align:left position:25%,start line:5% size:65% and this equation is called a saving score. 05:00.666 --> 05:03.400 align:left position:22.5%,start line:5% size:67.5% And you can think about this as the percent 05:03.500 --> 05:05.833 align:left position:15%,start line:5% size:75% that is recalled across time. 05:06.833 --> 05:10.066 align:left position:15%,start line:5% size:75% And what you can see is that the nature of forgetting 05:10.166 --> 05:12.600 align:left position:30%,start line:5% size:60% is such that soon after learning something, 05:12.700 --> 05:14.266 align:left position:32.5%,start line:5% size:57.5% we have pretty good memory for it. 05:14.366 --> 05:18.800 align:left position:12.5%,start line:5% size:77.5% But over time, that ability to retrieve the memory declines, 05:18.900 --> 05:23.466 align:left position:15%,start line:5% size:75% and it declines according to what we call a forgetting curve. 05:23.566 --> 05:27.700 align:left position:25%,start line:5% size:65% Okay, so the curve is fast-changing at first, 05:27.800 --> 05:29.800 align:left position:15%,start line:5% size:75% but then over time slows down 05:29.900 --> 05:32.833 align:left position:27.5%,start line:5% size:62.5% and gives sort of a U-shape to the curve. 05:34.633 --> 05:37.433 align:left position:32.5%,start line:5% size:57.5% And we've been studying this process 05:37.533 --> 05:39.100 align:left position:27.5%,start line:5% size:62.5% for a considerable amount of time, 05:39.200 --> 05:41.433 align:left position:15%,start line:5% size:75% dating back to the late 1800s 05:41.533 --> 05:44.166 align:left position:32.5%,start line:5% size:57.5% at the birth of psychological science. 05:44.266 --> 05:47.366 align:left position:12.5%,start line:5% size:77.5% So because forgetting has been such a well-studied process, 05:47.466 --> 05:49.633 align:left position:15%,start line:5% size:75% we know some things about it. 05:49.733 --> 05:52.300 align:left position:12.5%,start line:5% size:77.5% And I'm gonna give you a brief overview of what we know. 05:52.400 --> 05:56.633 align:left position:20%,start line:5% size:70% So first, we know that we forget across the lifespan. 05:56.733 --> 05:58.933 align:left position:25%,start line:5% size:65% So forgetting happens in young infants, 05:59.033 --> 06:01.233 align:left position:30%,start line:5% size:60% in adulthood, and in older adulthood. 06:01.333 --> 06:05.833 align:left position:12.5%,start line:5% size:77.5% In other words, every stage of life, we observe forgetting. 06:06.833 --> 06:08.433 align:left position:22.5%,start line:5% size:67.5% The next thing that we know about forgetting 06:08.533 --> 06:12.933 align:left position:17.5%,start line:5% size:72.5% is that forgetting happens across tasks and timescales. 06:13.033 --> 06:14.933 align:left position:32.5%,start line:5% size:57.5% And it's a very predictable pattern. 06:15.033 --> 06:18.233 align:left position:15%,start line:5% size:75% And in fact, that pattern is what I just showed you earlier, 06:18.333 --> 06:20.000 align:left position:25%,start line:5% size:65% the forgetting curve. 06:20.100 --> 06:22.666 align:left position:27.5%,start line:5% size:62.5% Now in this figure, what I have here 06:22.766 --> 06:24.766 align:left position:20%,start line:5% size:70% are two different graphs. 06:24.866 --> 06:26.833 align:left position:12.5%,start line:5% size:77.5% On the left side of the screen, 06:26.933 --> 06:29.700 align:left position:27.5%,start line:5% size:62.5% you'll see that the X-axis indicates time 06:29.800 --> 06:32.100 align:left position:22.5%,start line:5% size:67.5% as a matter of seconds. 06:32.200 --> 06:33.766 align:left position:17.5%,start line:5% size:72.5% However, on the right side, 06:33.866 --> 06:35.633 align:left position:27.5%,start line:5% size:62.5% there's a different dimension of time, 06:35.733 --> 06:39.666 align:left position:20%,start line:5% size:70% which is years, like 0 to 50 years in particular. 06:39.766 --> 06:41.600 align:left position:32.5%,start line:5% size:57.5% And then on the Y-axis for both graphs 06:41.700 --> 06:42.966 align:left position:22.5%,start line:5% size:67.5% is the percent correct. 06:43.066 --> 06:45.433 align:left position:25%,start line:5% size:65% That's the percentage remembered. 06:45.533 --> 06:46.666 align:left position:27.5%,start line:5% size:62.5% And what we can see 06:46.766 --> 06:48.833 align:left position:20%,start line:5% size:70% is regardless of whether or not the timescale 06:48.933 --> 06:51.600 align:left position:20%,start line:5% size:70% is a matter of seconds as such in the left graph, 06:51.700 --> 06:52.900 align:left position:25%,start line:5% size:65% or a matter of years, 06:53.000 --> 06:54.933 align:left position:27.5%,start line:5% size:62.5% such as what we see on the right graph, 06:55.033 --> 06:59.000 align:left position:12.5%,start line:5% size:77.5% we see the exact same pattern, that forgetting curve. 07:00.000 --> 07:02.000 align:left position:17.5%,start line:5% size:72.5% Now, for those of you that are mathematical buffs, 07:02.100 --> 07:06.100 align:left position:20%,start line:5% size:70% what you can see is that what is charted here 07:06.200 --> 07:07.333 align:left position:25%,start line:5% size:65% is a power function. 07:07.433 --> 07:09.933 align:left position:22.5%,start line:5% size:67.5% That's that equation at the top of the graphs. 07:10.033 --> 07:13.266 align:left position:22.5%,start line:5% size:67.5% And indeed, forgetting follows a power function 07:13.366 --> 07:14.733 align:left position:17.5%,start line:5% size:72.5% with a high degree of fit. 07:14.833 --> 07:16.300 align:left position:15%,start line:5% size:75% So those are squared values, 07:16.400 --> 07:18.700 align:left position:25%,start line:5% size:65% or what you're seeing is like the percentage 07:18.800 --> 07:21.800 align:left position:17.5%,start line:5% size:72.5% at which the power function can account 07:21.900 --> 07:25.233 align:left position:25%,start line:5% size:65% for the data that we observed via forgetting. 07:25.333 --> 07:27.400 align:left position:25%,start line:71% size:65% And one thing that's fascinating about forgetting 07:27.500 --> 07:28.600 align:left position:20%,start line:71% size:70% is that one of the things 07:28.700 --> 07:31.366 align:left position:17.5%,start line:71% size:72.5% that we can mathematically model the best 07:31.466 --> 07:32.966 align:left position:27.5%,start line:71% size:62.5% of human cognition. 07:33.066 --> 07:37.300 align:left position:12.5%,start line:71% size:77.5% Indeed, capturing about 88% or 90-some percent of the variance 07:37.400 --> 07:38.766 align:left position:35%,start line:71% size:55% is very high. 07:38.866 --> 07:42.400 align:left position:20%,start line:71% size:70% And so forgetting is very predictable across timescales, 07:42.500 --> 07:43.766 align:left position:22.5%,start line:71% size:67.5% but also across tasks. 07:43.866 --> 07:47.200 align:left position:15%,start line:5% size:75% We see the similar forgetting curves across tasks. 07:48.866 --> 07:50.733 align:left position:22.5%,start line:5% size:67.5% The next thing we know about forgetting 07:50.833 --> 07:52.733 align:left position:32.5%,start line:5% size:57.5% is that we can observe forgetting 07:52.833 --> 07:55.600 align:left position:12.5%,start line:5% size:77.5% on multiple levels of analysis. 07:55.700 --> 07:57.633 align:left position:32.5%,start line:5% size:57.5% In other words, we see forgetting 07:57.733 --> 08:01.300 align:left position:15%,start line:5% size:75% on the level of an individual neuron in our brain, 08:01.400 --> 08:03.666 align:left position:32.5%,start line:71% size:57.5% but we can also observe forgetting 08:03.766 --> 08:05.800 align:left position:17.5%,start line:71% size:72.5% in complex human behaviors, 08:05.900 --> 08:09.466 align:left position:20%,start line:71% size:70% such as those day-to-day functions that we engage in, 08:09.566 --> 08:11.800 align:left position:12.5%,start line:71% size:77.5% especially more complex things 08:11.900 --> 08:15.100 align:left position:17.5%,start line:71% size:72.5% like learning new concepts in the classroom. 08:15.200 --> 08:18.100 align:left position:17.5%,start line:71% size:72.5% So we're seeing forgetting at multiple levels 08:18.200 --> 08:19.966 align:left position:22.5%,start line:71% size:67.5% of our being as humans. 08:21.133 --> 08:23.333 align:left position:30%,start line:71% size:60% We also know that we're not alone. 08:24.466 --> 08:27.200 align:left position:27.5%,start line:71% size:62.5% Humans are not the only ones that forget. 08:27.300 --> 08:30.533 align:left position:20%,start line:5% size:70% We can observe forgetting in other species, 08:30.633 --> 08:34.033 align:left position:20%,start line:5% size:70% even organisms that don't have our nervous system. 08:34.133 --> 08:37.100 align:left position:32.5%,start line:5% size:57.5% So for example, in very simple organisms 08:37.200 --> 08:38.866 align:left position:30%,start line:5% size:60% that only have a matter of cells, 08:38.966 --> 08:41.866 align:left position:25%,start line:5% size:65% we observe that those cells will forget. 08:41.966 --> 08:43.400 align:left position:12.5%,start line:5% size:77.5% So forgetting is not something 08:43.500 --> 08:46.166 align:left position:27.5%,start line:5% size:62.5% that's specific to the human experience 08:46.266 --> 08:47.566 align:left position:22.5%,start line:71% size:67.5% or our nervous systems; 08:47.666 --> 08:51.833 align:left position:20%,start line:71% size:70% it's much more widespread across organisms. 08:53.233 --> 08:55.233 align:left position:22.5%,start line:71% size:67.5% Okay, so at this point, 08:56.466 --> 08:59.533 align:left position:22.5%,start line:71% size:67.5% what you were probably thinking is that, 08:59.633 --> 09:00.866 align:left position:12.5%,start line:71% size:77.5% "Wow, so what you're telling me 09:00.966 --> 09:03.900 align:left position:20%,start line:71% size:70% is that we're forgetting everything all the time." 09:04.000 --> 09:05.066 align:left position:30%,start line:71% size:60% And that's right. 09:05.166 --> 09:08.500 align:left position:30%,start line:71% size:60% We are forgetting everything all the time. 09:08.600 --> 09:11.600 align:left position:30%,start line:71% size:60% It is predictable and it's inevitable. 09:13.200 --> 09:15.266 align:left position:20%,start line:71% size:70% So why does this happen? 09:15.366 --> 09:17.466 align:left position:25%,start line:71% size:65% Why is this happening to us all the time 09:17.566 --> 09:18.700 align:left position:20%,start line:71% size:70% in a predictable manner? 09:18.800 --> 09:22.100 align:left position:27.5%,start line:71% size:62.5% Well, the truth is, is that we don't know. 09:22.200 --> 09:24.066 align:left position:17.5%,start line:89% size:72.5% It's a scientific mystery. 09:24.166 --> 09:27.066 align:left position:27.5%,start line:83% size:62.5% We don't know what causes forgetting, 09:27.166 --> 09:30.000 align:left position:25%,start line:83% size:65% but currently, there are two primary theories 09:30.100 --> 09:32.533 align:left position:12.5%,start line:89% size:77.5% about why it is that we forget. 09:33.866 --> 09:38.033 align:left position:22.5%,start line:83% size:67.5% The first collection of theories focus on interference. 09:38.133 --> 09:40.900 align:left position:32.5%,start line:83% size:57.5% In other words, these theories posit 09:41.000 --> 09:43.600 align:left position:27.5%,start line:83% size:62.5% that because we're continually acquiring 09:43.700 --> 09:45.800 align:left position:17.5%,start line:89% size:72.5% more and more information, 09:45.900 --> 09:49.133 align:left position:20%,start line:71% size:70% that that new information blocks us from retrieving 09:49.233 --> 09:52.766 align:left position:27.5%,start line:71% size:62.5% the old information in our mind and brain. 09:52.866 --> 09:54.833 align:left position:27.5%,start line:71% size:62.5% So if we weren't to learn anything new, 09:54.933 --> 09:56.066 align:left position:27.5%,start line:71% size:62.5% we wouldn't forget, 09:56.166 --> 09:58.200 align:left position:27.5%,start line:71% size:62.5% is essentially what they're arguing. 09:59.566 --> 10:02.933 align:left position:27.5%,start line:71% size:62.5%   However, there's a different collection of theories 10:03.033 --> 10:07.133 align:left position:17.5%,start line:83% size:72.5% that center on time and the properties of the universe 10:07.233 --> 10:09.300 align:left position:22.5%,start line:89% size:67.5% with regards to energy. 10:09.400 --> 10:12.066 align:left position:12.5%,start line:83% size:77.5% So according to these theories, the reason that we forget 10:12.166 --> 10:15.466 align:left position:25%,start line:83% size:65% is that energy passes across biological membranes 10:15.566 --> 10:18.666 align:left position:10%,start line:83% size:80% according to this power function that you've seen earlier, 10:18.766 --> 10:20.833 align:left position:32.5%,start line:83% size:57.5% in other words, the forgetting curve. 10:21.833 --> 10:23.766 align:left position:25%,start line:89% size:65% And because of that, 10:23.866 --> 10:26.833 align:left position:20%,start line:71% size:70% we observe forgetting at different units of analysis, 10:26.933 --> 10:29.666 align:left position:15%,start line:71% size:75% like a single cell, but also, 10:29.766 --> 10:33.633 align:left position:20%,start line:71% size:70% that scales up to complex human behavior as well. 10:34.900 --> 10:39.600 align:left position:12.5%,start line:71% size:77.5% Now, one issue is that we can't control for time and energy. 10:39.700 --> 10:42.133 align:left position:20%,start line:71% size:70% In other words, we can't put people in a vacuum 10:42.233 --> 10:44.266 align:left position:30%,start line:71% size:60% where they're not experiencing time 10:44.366 --> 10:48.766 align:left position:12.5%,start line:71% size:77.5% in order to understand whether it's truly interference or time. 10:48.866 --> 10:51.566 align:left position:12.5%,start line:71% size:77.5% Moreover, we can't control time 10:51.666 --> 10:53.366 align:left position:30%,start line:71% size:60% when we're doing interference studies. 10:53.466 --> 10:58.100 align:left position:17.5%,start line:71% size:72.5% So with additional learning comes additional time. 10:58.200 --> 11:00.300 align:left position:30%,start line:71% size:60% And so the reason that it's a mystery, 11:00.400 --> 11:02.133 align:left position:27.5%,start line:71% size:62.5% is it interference or is it something 11:02.233 --> 11:04.600 align:left position:25%,start line:71% size:65% about the properties of the universe? 11:04.700 --> 11:05.833 align:left position:22.5%,start line:71% size:67.5% We just may never know 11:05.933 --> 11:08.000 align:left position:25%,start line:71% size:65% because we can't put ourselves in a vacuum 11:08.100 --> 11:11.600 align:left position:27.5%,start line:71% size:62.5% in order to control these two variables. 11:11.700 --> 11:12.866 align:left position:22.5%,start line:71% size:67.5% So the debate rages on, 11:12.966 --> 11:15.866 align:left position:17.5%,start line:71% size:72.5% but we're pretty sure that it's either interference, 11:15.966 --> 11:18.633 align:left position:35%,start line:71% size:55% time, or some combination of the two. 11:20.133 --> 11:23.233 align:left position:35%,start line:71% size:55%   Okay, so that was the overview of forgetting, 11:23.333 --> 11:25.933 align:left position:27.5%,start line:83% size:62.5% what it is and what we know about it. 11:26.033 --> 11:29.633 align:left position:17.5%,start line:83% size:72.5% Now I'd like to move on and I'd like to tell you more 11:29.733 --> 11:32.266 align:left position:22.5%,start line:83% size:67.5% about why forgetting is actually a good thing, 11:32.366 --> 11:34.500 align:left position:25%,start line:83% size:65% because at this point you might be wondering, 11:34.600 --> 11:37.633 align:left position:32.5%,start line:83% size:57.5% "Well, if it's inevitable, predictable, 11:37.733 --> 11:39.633 align:left position:25%,start line:71% size:65% "and gonna prevent us from remembering things, 11:39.733 --> 11:41.133 align:left position:30%,start line:71% size:60% it must be bad." 11:41.233 --> 11:43.000 align:left position:22.5%,start line:71% size:67.5% Well, it turns out that that's not the case. 11:43.100 --> 11:45.866 align:left position:22.5%,start line:71% size:67.5% Forgetting can be used to help us remember. 11:47.233 --> 11:51.333 align:left position:12.5%,start line:71% size:77.5% So if forgetting is inevitable, how do we remember? 11:51.433 --> 11:55.566 align:left position:10%,start line:71% size:80% This has been a central research question for many years. 11:55.666 --> 11:57.800 align:left position:25%,start line:71% size:65% And what researchers have discovered 11:57.900 --> 12:00.000 align:left position:30%,start line:71% size:60% are that certain learning environments 12:00.100 --> 12:04.433 align:left position:10%,start line:71% size:80% or conditions of the environment can actually improve our memory. 12:04.533 --> 12:07.666 align:left position:27.5%,start line:71% size:62.5% They can help us to retrieve information. 12:07.766 --> 12:09.566 align:left position:32.5%,start line:71% size:57.5% One of the most well-studied conditions 12:09.666 --> 12:13.033 align:left position:17.5%,start line:71% size:72.5% of the learning environment is called spaced learning. 12:13.133 --> 12:15.000 align:left position:17.5%,start line:71% size:72.5%   And what scientists have observed 12:15.100 --> 12:18.500 align:left position:17.5%,start line:83% size:72.5% is that when we distribute learning events across time, 12:18.600 --> 12:21.433 align:left position:20%,start line:83% size:70% people have better memory for that information 12:21.533 --> 12:24.800 align:left position:17.5%,start line:83% size:72.5% compared to it being massed in immediate succession. 12:26.566 --> 12:28.666 align:left position:15%,start line:71% size:75% So here's a real life example of that. 12:28.766 --> 12:32.233 align:left position:25%,start line:71% size:65% Imagine that you are studying for a test. 12:32.333 --> 12:34.133 align:left position:15%,start line:71% size:75% You have one or two options: 12:34.233 --> 12:37.166 align:left position:12.5%,start line:71% size:77.5% you could cram the night before and just cram, cram, cram 12:37.266 --> 12:39.066 align:left position:20%,start line:71% size:70% right up until the test. 12:39.166 --> 12:41.233 align:left position:15%,start line:71% size:75% Well, that behavior would be 12:41.333 --> 12:43.166 align:left position:25%,start line:71% size:65% studying in immediate succession. 12:43.266 --> 12:45.900 align:left position:27.5%,start line:71% size:62.5% We would call that massed learning. 12:46.000 --> 12:49.200 align:left position:22.5%,start line:71% size:67.5% The other option is to distribute your learning 12:49.300 --> 12:51.900 align:left position:20%,start line:71% size:70% during the week and study a little bit every day. 12:52.000 --> 12:53.766 align:left position:25%,start line:71% size:65% So you might study a little bit on Monday, 12:53.866 --> 12:54.933 align:left position:20%,start line:71% size:70% a little bit on Tuesday, 12:55.033 --> 12:57.700 align:left position:20%,start line:71% size:70% a little bit on Wednesday and so on and so forth, 12:57.800 --> 13:00.200 align:left position:20%,start line:71% size:70% building up to the test. 13:00.300 --> 13:02.700 align:left position:30%,start line:71% size:60% And what you may experience if you cram 13:02.800 --> 13:05.700 align:left position:10%,start line:71% size:80% is that you do okay on the test, you do well enough, 13:05.800 --> 13:07.300 align:left position:25%,start line:71% size:65% but a few days later you might say, 13:07.400 --> 13:09.766 align:left position:12.5%,start line:71% size:77.5% "Wow, I don't remember anything 13:09.866 --> 13:12.933 align:left position:20%,start line:71% size:70% from the test that I took earlier in the week." 13:13.033 --> 13:15.033 align:left position:27.5%,start line:71% size:62.5% However, if you had distributed your learning 13:15.133 --> 13:17.000 align:left position:15%,start line:71% size:75% or spaced it out across time, 13:17.100 --> 13:20.100 align:left position:27.5%,start line:71% size:62.5% you would probably experience more memory 13:20.200 --> 13:21.433 align:left position:20%,start line:71% size:70% for what you studied for. 13:21.533 --> 13:23.733 align:left position:25%,start line:71% size:65% In other words, you'd actually remember 13:23.833 --> 13:25.100 align:left position:22.5%,start line:71% size:67.5% what you were studying. 13:26.100 --> 13:30.433 align:left position:12.5%,start line:71% size:77.5% And that's a real life example of how spaced learning 13:30.533 --> 13:34.433 align:left position:15%,start line:71% size:75% promotes memory to a greater degree than massed learning. 13:35.433 --> 13:38.800 align:left position:22.5%,start line:71% size:67.5% In the lab, scientists do this kind of work 13:38.900 --> 13:40.400 align:left position:30%,start line:71% size:60% using word lists. 13:40.500 --> 13:44.066 align:left position:15%,start line:5% size:75% What they do is they present words to participants 13:44.166 --> 13:45.666 align:left position:32.5%,start line:5% size:57.5% one at a time. 13:45.766 --> 13:47.633 align:left position:25%,start line:5% size:65% So what you're seeing here on this list 13:47.733 --> 13:50.233 align:left position:25%,start line:5% size:65% is a series of words, and what you'll notice 13:50.333 --> 13:52.766 align:left position:25%,start line:5% size:65% is some of the words like the word cat 13:52.866 --> 13:54.766 align:left position:30%,start line:5% size:60% are presented in immediate succession, 13:54.866 --> 13:57.033 align:left position:17.5%,start line:5% size:72.5% one right after the other. 13:57.133 --> 14:00.100 align:left position:10%,start line:5% size:80% Whereas other words on the list, such as the word dog, 14:00.200 --> 14:01.633 align:left position:17.5%,start line:5% size:72.5% is distributed across time. 14:01.733 --> 14:02.833 align:left position:20%,start line:5% size:70% You'll see the word dog, 14:02.933 --> 14:04.233 align:left position:27.5%,start line:5% size:62.5% and then you'll see some other words 14:04.333 --> 14:06.433 align:left position:25%,start line:5% size:65% and then the word dog will come back. 14:06.533 --> 14:08.866 align:left position:22.5%,start line:5% size:67.5% The consistent finding across these studies 14:08.966 --> 14:10.800 align:left position:27.5%,start line:5% size:62.5% that use word lists is that participants 14:10.900 --> 14:13.900 align:left position:15%,start line:5% size:75% have stronger memory for the words distributed across time, 14:14.000 --> 14:17.333 align:left position:20%,start line:5% size:70% like dog, relative to the words that are massed in time, 14:17.433 --> 14:18.866 align:left position:27.5%,start line:5% size:62.5% like the word cat. 14:20.400 --> 14:23.500 align:left position:27.5%,start line:83% size:62.5% We know from over a thousand published studies 14:23.600 --> 14:25.100 align:left position:25%,start line:83% size:65% that spaced learning promotes memory. 14:25.200 --> 14:27.333 align:left position:35%,start line:83% size:55% It's a highly replicable phenomenon 14:27.433 --> 14:29.733 align:left position:27.5%,start line:83% size:62.5% that's been studied across many timescales 14:29.833 --> 14:32.100 align:left position:27.5%,start line:89% size:62.5% and many contexts. 14:32.200 --> 14:34.200 align:left position:17.5%,start line:89% size:72.5% One of the primary reasons 14:34.300 --> 14:37.466 align:left position:25%,start line:83% size:65% that spaced learning supports memory 14:37.566 --> 14:39.900 align:left position:30%,start line:83% size:60% is actually that we're forgetting 14:40.000 --> 14:41.800 align:left position:17.5%,start line:89% size:72.5% during the learning events. 14:41.900 --> 14:45.300 align:left position:30%,start line:83% size:60% So let me briefly describe why this happens. 14:45.400 --> 14:48.000 align:left position:27.5%,start line:83% size:62.5% So in between each spaced learning event, 14:48.100 --> 14:49.900 align:left position:17.5%,start line:89% size:72.5% you'll forget information. 14:50.000 --> 14:51.333 align:left position:15%,start line:71% size:75% And what that forgetting does 14:51.433 --> 14:54.733 align:left position:20%,start line:71% size:70% is it makes it harder to retrieve what you've learned. 14:54.833 --> 14:56.400 align:left position:30%,start line:71% size:60% But at subsequent learning events, 14:56.500 --> 14:58.033 align:left position:30%,start line:71% size:60% what you'll do is you'll retrieve 14:58.133 --> 15:01.033 align:left position:22.5%,start line:71% size:67.5% your prior information from memory 15:01.133 --> 15:03.633 align:left position:20%,start line:71% size:70% and the cognitive effort that you engage in 15:03.733 --> 15:06.000 align:left position:12.5%,start line:71% size:77.5% in remembering that information 15:06.100 --> 15:09.400 align:left position:22.5%,start line:71% size:67.5% will then be translated into a slower forgetting 15:09.500 --> 15:10.766 align:left position:25%,start line:71% size:65% for that information. 15:10.866 --> 15:12.766 align:left position:32.5%,start line:71% size:57.5% In other words, by trying to remember 15:12.866 --> 15:14.833 align:left position:12.5%,start line:71% size:77.5% and practicing that retrieval, 15:14.933 --> 15:18.500 align:left position:20%,start line:71% size:70% you'll then have a slower forgetting rate in the future. 15:18.600 --> 15:21.433 align:left position:17.5%,start line:71% size:72.5% And so by engaging in that retrieval practice 15:21.533 --> 15:23.633 align:left position:27.5%,start line:71% size:62.5% across distributed learning events, 15:23.733 --> 15:25.366 align:left position:32.5%,start line:71% size:57.5% you're actually slowing forgetting 15:25.466 --> 15:27.600 align:left position:17.5%,start line:71% size:72.5% and promoting your memory. 15:28.600 --> 15:31.100 align:left position:25%,start line:83% size:65% Now, researchers have for a long time now 15:31.200 --> 15:33.100 align:left position:17.5%,start line:83% size:72.5% known that spaced learning promotes memory 15:33.200 --> 15:37.000 align:left position:17.5%,start line:83% size:72.5% and that forgetting can be manipulated to promote memory, 15:37.100 --> 15:41.800 align:left position:27.5%,start line:83% size:62.5% but this isn't true for all forms of memory. 15:41.900 --> 15:44.100 align:left position:20%,start line:83% size:70% For example, researchers have questioned 15:44.200 --> 15:46.266 align:left position:27.5%,start line:83% size:62.5% whether or not this process of forgetting 15:46.366 --> 15:48.000 align:left position:22.5%,start line:89% size:67.5% is good for everything. 15:49.100 --> 15:52.033 align:left position:27.5%,start line:83% size:62.5% And in particular, researchers have asked, 15:52.133 --> 15:55.700 align:left position:22.5%,start line:83% size:67.5% can forgetting promote categorization 15:55.800 --> 15:57.400 align:left position:25%,start line:89% size:65% and concept learning? 15:58.733 --> 16:00.433 align:left position:22.5%,start line:83% size:67.5% And the categorization and concept learning 16:00.533 --> 16:02.733 align:left position:22.5%,start line:83% size:67.5% is learning that things share similarities 16:02.833 --> 16:03.900 align:left position:15%,start line:89% size:75% and differences in the world. 16:04.000 --> 16:07.633 align:left position:20%,start line:71% size:70% So for example, a golden retriever is called a dog 16:07.733 --> 16:09.900 align:left position:27.5%,start line:71% size:62.5% and a wiener dog is also called a dog. 16:10.000 --> 16:11.233 align:left position:30%,start line:71% size:60% Even though they look very different, 16:11.333 --> 16:13.533 align:left position:22.5%,start line:71% size:67.5% they share similarities and thus belong 16:13.633 --> 16:15.533 align:left position:22.5%,start line:71% size:67.5% to the category of dog. 16:16.966 --> 16:18.700 align:left position:10%,start line:71% size:80% And general intuition would say, 16:18.800 --> 16:21.100 align:left position:25%,start line:71% size:65% "Hmm, I don't know if forgetting is good," 16:21.200 --> 16:23.000 align:left position:27.5%,start line:71% size:62.5% because in general, intuition tells us 16:23.100 --> 16:25.933 align:left position:15%,start line:71% size:75% that forgetting is not good, that it's a bad thing. 16:26.033 --> 16:29.033 align:left position:20%,start line:71% size:70% However, even researchers who are experts in this field 16:29.133 --> 16:31.133 align:left position:22.5%,start line:71% size:67.5% really argued that yes, 16:31.233 --> 16:33.633 align:left position:30%,start line:71% size:60% forgetting should deter categorization 16:33.733 --> 16:35.500 align:left position:25%,start line:71% size:65% in concept learning. 16:35.600 --> 16:39.500 align:left position:17.5%,start line:71% size:72.5% It's really fun to go back through the previous literature 16:39.600 --> 16:41.600 align:left position:25%,start line:71% size:65% and read old studies 16:41.700 --> 16:43.500 align:left position:25%,start line:71% size:65% because there's some fighting words out there. 16:43.600 --> 16:45.333 align:left position:10%,start line:71% size:80% People really had strong beliefs 16:45.433 --> 16:48.866 align:left position:17.5%,start line:71% size:72.5% that forgetting would deter conceptual development. 16:48.966 --> 16:51.100 align:left position:25%,start line:71% size:65% My favorite quote is from Ernie Rothkopf, 16:51.200 --> 16:52.733 align:left position:25%,start line:71% size:65%   where he argued that things like forgetting 16:52.833 --> 16:55.400 align:left position:20%,start line:83% size:70% and spaced learning would be the "friend of recall," 16:55.500 --> 16:59.000 align:left position:22.5%,start line:83% size:67.5% so help us to remember, "but the enemy of induction." 16:59.100 --> 17:01.933 align:left position:17.5%,start line:83% size:72.5% So in other words, it would deter our ability 17:02.033 --> 17:04.033 align:left position:27.5%,start line:83% size:62.5% to learn categories or learn concepts 17:04.133 --> 17:07.700 align:left position:15%,start line:83% size:75% where we have to abstract out across our experiences. 17:07.800 --> 17:10.466 align:left position:32.5%,start line:83% size:57.5% Let me walk you through this argument. 17:10.566 --> 17:13.566 align:left position:32.5%,start line:83% size:57.5% So imagine that you're a young child 17:13.666 --> 17:15.366 align:left position:27.5%,start line:83% size:62.5% and you're learning about the category 17:15.466 --> 17:18.100 align:left position:15%,start line:89% size:75% of bunny for the first time. 17:18.200 --> 17:20.466 align:left position:25%,start line:5% size:65% You'll see one bunny in one context, 17:20.566 --> 17:22.733 align:left position:17.5%,start line:5% size:72.5% and then you'll see another bunny in another context. 17:22.833 --> 17:26.366 align:left position:10%,start line:5% size:80% Then you might see a third bunny in a different context, 17:26.466 --> 17:27.600 align:left position:22.5%,start line:5% size:67.5% and what you need to do 17:27.700 --> 17:30.233 align:left position:30%,start line:5% size:60% in order to learn the category of bunny 17:30.333 --> 17:33.266 align:left position:22.5%,start line:5% size:67.5% is to abstract out the similarities and differences 17:33.366 --> 17:35.266 align:left position:20%,start line:5% size:70% across these experiences. 17:35.366 --> 17:36.633 align:left position:22.5%,start line:5% size:67.5% So you might see that, 17:36.733 --> 17:39.266 align:left position:30%,start line:5% size:60% well, the bunnies share the same shape. 17:39.366 --> 17:41.666 align:left position:27.5%,start line:5% size:62.5% And so maybe that's a relevant feature 17:41.766 --> 17:43.833 align:left position:20%,start line:5% size:70% of the category of bunny. 17:43.933 --> 17:46.100 align:left position:20%,start line:5% size:70% However, there are other features that vary. 17:46.200 --> 17:47.433 align:left position:30%,start line:5% size:60% So for instance, 17:47.533 --> 17:50.566 align:left position:20%,start line:5% size:70% the color of the hair is different across these bunnies. 17:50.666 --> 17:51.933 align:left position:20%,start line:5% size:70% And a child might think, 17:52.033 --> 17:55.566 align:left position:15%,start line:5% size:75% "Hmm, I guess the hair color is not a relevant category. 17:55.666 --> 17:58.166 align:left position:22.5%,start line:5% size:67.5% It's irrelevant to the category of bunny." 17:59.166 --> 18:01.100 align:left position:27.5%,start line:5% size:62.5% And the reason that children need to abstract 18:01.200 --> 18:02.300 align:left position:20%,start line:5% size:70% across these experiences 18:02.400 --> 18:03.900 align:left position:25%,start line:5% size:65% is they have to know what to generalize 18:04.000 --> 18:05.633 align:left position:27.5%,start line:5% size:62.5% based on when they see new bunnies 18:05.733 --> 18:07.466 align:left position:12.5%,start line:5% size:77.5% that they've never seen before. 18:08.466 --> 18:11.166 align:left position:22.5%,start line:5% size:67.5% They should generalize based on body shape 18:11.266 --> 18:13.833 align:left position:20%,start line:5% size:70% rather than on something like the color of the hair. 18:14.833 --> 18:17.633 align:left position:25%,start line:71% size:65% Now, Ernie and others thought that the forgetting 18:17.733 --> 18:19.600 align:left position:20%,start line:71% size:70% would deter this process 18:19.700 --> 18:21.433 align:left position:27.5%,start line:71% size:62.5% because how are you supposed to abstract 18:21.533 --> 18:23.133 align:left position:12.5%,start line:71% size:77.5% across all of your experiences 18:23.233 --> 18:26.000 align:left position:25%,start line:71% size:65% if you can't remember your experiences? 18:26.100 --> 18:29.666 align:left position:17.5%,start line:71% size:72.5% So for instance, if you can only remember the body shape 18:29.766 --> 18:31.466 align:left position:10%,start line:71% size:80% of one bunny you've seen before, 18:31.566 --> 18:34.633 align:left position:25%,start line:71% size:65% how are you supposed to know that body shape 18:34.733 --> 18:37.166 align:left position:25%,start line:71% size:65% is a relevant feature to the category of bunny? 18:37.266 --> 18:39.566 align:left position:27.5%,start line:71% size:62.5% You can't remember that all the bunnies 18:39.666 --> 18:41.766 align:left position:17.5%,start line:71% size:72.5% shared the same body shape. 18:41.866 --> 18:44.433 align:left position:32.5%,start line:71% size:57.5% Same thing goes for irrelevant features. 18:44.533 --> 18:46.533 align:left position:32.5%,start line:71% size:57.5% If you only see one color of hair 18:46.633 --> 18:47.933 align:left position:10%,start line:71% size:80% and you don't see that it varies 18:48.033 --> 18:49.733 align:left position:32.5%,start line:71% size:57.5% across all the different bunnies, 18:49.833 --> 18:53.033 align:left position:20%,start line:71% size:70% you might think that hair is a relevant feature. 18:53.133 --> 18:55.800 align:left position:35%,start line:71% size:55% You know, the first bunny you see 18:55.900 --> 18:57.900 align:left position:20%,start line:71% size:70% might be a certain color 18:58.000 --> 18:59.533 align:left position:27.5%,start line:71% size:62.5% and you would think that that color 18:59.633 --> 19:03.233 align:left position:22.5%,start line:71% size:67.5% defines the category of bunny when it does not. 19:03.333 --> 19:06.800 align:left position:15%,start line:71% size:75% So in other words, forgetting should be bad for abstraction. 19:07.800 --> 19:10.400 align:left position:12.5%,start line:71% size:77.5% Now what's interesting is that despite these fighting words 19:10.500 --> 19:13.333 align:left position:12.5%,start line:71% size:77.5% being out there and strong-held belief by researchers, 19:13.433 --> 19:15.400 align:left position:15%,start line:71% size:75% no one had really tested it. 19:15.500 --> 19:19.533 align:left position:20%,start line:71% size:70% So what we decided to do was to test this hypothesis, 19:19.633 --> 19:22.733 align:left position:20%,start line:71% size:70%   and one of the most common methodologies that we've used 19:22.833 --> 19:24.100 align:left position:22.5%,start line:89% size:67.5% to test this hypothesis 19:24.200 --> 19:27.566 align:left position:27.5%,start line:83% size:62.5% is called the novel category induction task. 19:27.666 --> 19:29.866 align:left position:20%,start line:83% size:70% And this task is designed for young children 19:29.966 --> 19:33.133 align:left position:17.5%,start line:83% size:72.5% who are learning words and categories for the first time. 19:33.233 --> 19:36.300 align:left position:15%,start line:83% size:75% And what we do is we present them with novel objects 19:36.400 --> 19:38.500 align:left position:20%,start line:71% size:70% and novel words to ensure that they're learning 19:38.600 --> 19:41.566 align:left position:22.5%,start line:71% size:67.5% these objects and words for the first time. 19:41.666 --> 19:43.666 align:left position:22.5%,start line:71% size:67.5% So just as an example, 19:43.766 --> 19:45.900 align:left position:32.5%,start line:71% size:57.5% an experimenter might show children 19:46.000 --> 19:48.933 align:left position:12.5%,start line:71% size:77.5% a series of novel objects like this and label them and say, 19:49.033 --> 19:52.400 align:left position:12.5%,start line:71% size:77.5%   "This is a wug, this is a wug, and this is a wug." 19:52.500 --> 19:56.933 align:left position:20%,start line:83% size:70% And then at a post-test, present children 19:57.033 --> 19:58.466 align:left position:20%,start line:89% size:70% with a series of objects. 19:58.566 --> 20:01.033 align:left position:22.5%,start line:83% size:67.5% Some they've never seen before, some they have. 20:01.133 --> 20:03.633 align:left position:22.5%,start line:83% size:67.5% So for example, they'd seen a cat before. 20:03.733 --> 20:07.333 align:left position:15%,start line:83% size:75% And then it's the child's job to generalize the category 20:07.433 --> 20:10.133 align:left position:17.5%,start line:83% size:72.5% that they just learned to a new instance of the category. 20:10.233 --> 20:12.133 align:left position:20%,start line:83% size:70% So what the experimenter would say is, 20:12.233 --> 20:13.833 align:left position:17.5%,start line:89% size:72.5% "Can you hand me the wug?" 20:13.933 --> 20:17.366 align:left position:12.5%,start line:83% size:77.5% And it would be the child's job to pick up that novel wug 20:17.466 --> 20:20.366 align:left position:15%,start line:83% size:75% they haven't seen before that shares a similar feature, 20:20.466 --> 20:23.800 align:left position:17.5%,start line:83% size:72.5% in this case shape, to the objects that they saw 20:23.900 --> 20:25.733 align:left position:30%,start line:89% size:60% during learning. 20:25.833 --> 20:29.533 align:left position:15%,start line:83% size:75% So this is referred to as the novel category induction task. 20:30.533 --> 20:32.800 align:left position:20%,start line:83% size:70% And today I'm gonna show you two experiments, 20:32.900 --> 20:34.733 align:left position:25%,start line:71% size:65% Experiments 1 and 2. 20:34.833 --> 20:37.300 align:left position:15%,start line:71% size:75% And the participants in these experiments were typically 20:37.400 --> 20:39.500 align:left position:10%,start line:71% size:80% developing two to two and a half year-old children. 20:39.600 --> 20:41.300 align:left position:27.5%,start line:71% size:62.5% And again, we were really interested 20:41.400 --> 20:42.833 align:left position:17.5%,start line:71% size:72.5% in how this process unfolds 20:42.933 --> 20:46.033 align:left position:12.5%,start line:71% size:77.5% when it's organically unfolding a lot during development, 20:46.133 --> 20:48.166 align:left position:15%,start line:71% size:75% which is the toddler period. 20:48.266 --> 20:50.966 align:left position:20%,start line:71% size:70% They're learning lots of words and new categories 20:51.066 --> 20:52.566 align:left position:17.5%,start line:71% size:72.5% during the toddler period. 20:53.566 --> 20:58.466 align:left position:10%,start line:83% size:80% We made very simple manipulation on the classic paradigm. 20:58.566 --> 21:00.366 align:left position:12.5%,start line:89% size:77.5% And what we did in Experiment 1 21:00.466 --> 21:04.666 align:left position:20%,start line:83% size:70% is we presented children with novel words and objects 21:04.766 --> 21:09.433 align:left position:17.5%,start line:83% size:72.5% on one of three schedules: simultaneous, massed, or spaced. 21:09.533 --> 21:10.600 align:left position:17.5%,start line:89% size:72.5% I'm gonna walk you through 21:10.700 --> 21:13.200 align:left position:17.5%,start line:83% size:72.5% each of these presentation schedules now. 21:13.300 --> 21:15.366 align:left position:12.5%,start line:89% size:77.5% In the simultaneous condition, 21:15.466 --> 21:18.133 align:left position:15%,start line:83% size:75% children were presented with four objects at the same time. 21:18.233 --> 21:21.466 align:left position:20%,start line:83% size:70% They were all put on the table simultaneously. 21:21.566 --> 21:24.966 align:left position:12.5%,start line:83% size:77.5% What the experimenter would do, would label each of the objects. 21:25.066 --> 21:26.300 align:left position:12.5%,start line:89% size:77.5% So the experimenter would say, 21:26.400 --> 21:29.366 align:left position:17.5%,start line:83% size:72.5% "Look, this is a wug," and point to the first object. 21:29.466 --> 21:30.533 align:left position:17.5%,start line:89% size:72.5% They would wait 10 seconds 21:30.633 --> 21:32.333 align:left position:25%,start line:83% size:65% and then point to the second object and say, 21:32.433 --> 21:34.300 align:left position:22.5%,start line:89% size:67.5% "Look, this is a wug," 21:34.400 --> 21:36.200 align:left position:27.5%,start line:83% size:62.5% wait 10 seconds and so on and so forth 21:36.300 --> 21:38.833 align:left position:25%,start line:89% size:65% for all four objects. 21:38.933 --> 21:41.800 align:left position:22.5%,start line:83% size:67.5% Now in this condition, forgetting is minimized 21:41.900 --> 21:45.000 align:left position:17.5%,start line:83% size:72.5% because all of the objects are present to the child 21:45.100 --> 21:46.300 align:left position:30%,start line:89% size:60% at the same time. 21:46.400 --> 21:49.400 align:left position:20%,start line:71% size:70% And they keep hearing the word wug over and over again. 21:49.500 --> 21:51.900 align:left position:22.5%,start line:71% size:67.5% So children don't have to rely on their memory 21:52.000 --> 21:54.800 align:left position:15%,start line:71% size:75% to abstract out what are the similarities and differences 21:54.900 --> 21:55.966 align:left position:27.5%,start line:71% size:62.5% among the objects. 21:56.066 --> 21:58.966 align:left position:20%,start line:71% size:70% They're all on the table at the same time. 22:00.400 --> 22:02.500 align:left position:20%,start line:71% size:70% The second condition was the massed condition. 22:02.600 --> 22:03.733 align:left position:22.5%,start line:71% size:67.5% And in this condition, 22:03.833 --> 22:06.700 align:left position:25%,start line:83% size:65% we presented children with objects one at a time. 22:06.800 --> 22:09.466 align:left position:20%,start line:83% size:70% So the experimenter would put an object on the table 22:09.566 --> 22:11.400 align:left position:12.5%,start line:89% size:77.5% and say, "Look, this is a wug," 22:11.500 --> 22:14.400 align:left position:25%,start line:83% size:65% wait 10 seconds, take the object off the table, 22:14.500 --> 22:16.066 align:left position:32.5%,start line:83% size:57.5% and then put it back on the table 22:16.166 --> 22:18.166 align:left position:25%,start line:83% size:65% or put another object on the table and say, 22:18.266 --> 22:20.333 align:left position:22.5%,start line:89% size:67.5% "Look, this is a wug," 22:20.433 --> 22:22.533 align:left position:15%,start line:83% size:75% wait 10 seconds for the child to play with the toy, 22:22.633 --> 22:24.900 align:left position:25%,start line:83% size:65% take it off, and then put a third object on, 22:25.000 --> 22:26.333 align:left position:22.5%,start line:89% size:67.5% and so on and so forth. 22:26.433 --> 22:29.666 align:left position:12.5%,start line:83% size:77.5% So in other words, the objects were presented one at a time. 22:29.766 --> 22:31.200 align:left position:30%,start line:89% size:60% Now in this case, 22:31.300 --> 22:34.166 align:left position:20%,start line:83% size:70% children need to rely on their memory a little bit 22:34.266 --> 22:36.133 align:left position:30%,start line:83% size:60% to remember what they've seen earlier. 22:36.233 --> 22:37.733 align:left position:30%,start line:83% size:60% Because they only see one at a time, 22:37.833 --> 22:39.000 align:left position:20%,start line:89% size:70% they have to think back, 22:39.100 --> 22:41.300 align:left position:17.5%,start line:83% size:72.5% "Hmm, what were the colors and shapes of the objects 22:41.400 --> 22:42.766 align:left position:25%,start line:89% size:65% that I saw earlier?" 22:44.100 --> 22:46.966 align:left position:22.5%,start line:83% size:67.5% The final condition was the spaced condition. 22:47.066 --> 22:49.333 align:left position:27.5%,start line:83% size:62.5% In this condition, what children did 22:49.433 --> 22:52.333 align:left position:17.5%,start line:83% size:72.5% is they also saw one object at a time, 22:52.433 --> 22:54.833 align:left position:17.5%,start line:83% size:72.5% but instead of seeing them in immediate succession, 22:54.933 --> 22:58.066 align:left position:15%,start line:83% size:75% like in the massed condition, there were 30-second delays 22:58.166 --> 23:01.333 align:left position:20%,start line:83% size:70% between each presentation of the object. 23:01.433 --> 23:04.033 align:left position:20%,start line:83% size:70% So what children would do is they'd see an object, 23:04.133 --> 23:06.033 align:left position:17.5%,start line:83% size:72.5% the experimenter would put one on the table and say, 23:06.133 --> 23:07.200 align:left position:22.5%,start line:89% size:67.5% "Look, this is a wug." 23:07.300 --> 23:09.400 align:left position:20%,start line:83% size:70% And then the experimenter would take it away. 23:09.500 --> 23:12.366 align:left position:20%,start line:83% size:70% And there'd be 30 seconds of irrelevant activities 23:12.466 --> 23:15.600 align:left position:17.5%,start line:71% size:72.5% like playing with Play-Doh, putting stickers on paper, 23:15.700 --> 23:19.000 align:left position:20%,start line:71% size:70% anything to keep the kids at the table and entertained. 23:19.100 --> 23:20.933 align:left position:25%,start line:71% size:65% After that 30-second play period, 23:21.033 --> 23:23.900 align:left position:22.5%,start line:71% size:67.5% children would then be presented with another object 23:24.000 --> 23:26.833 align:left position:12.5%,start line:71% size:77.5% and the experimenter would say, "Look, this is a wug." 23:26.933 --> 23:28.633 align:left position:25%,start line:71% size:65% And that would happen so on and so forth 23:28.733 --> 23:30.933 align:left position:17.5%,start line:71% size:72.5% for four objects in total. 23:32.633 --> 23:35.266 align:left position:25%,start line:83% size:65% Now what you can see across these conditions 23:35.366 --> 23:37.766 align:left position:22.5%,start line:83% size:67.5% is that the only thing that's being manipulated here 23:37.866 --> 23:38.933 align:left position:32.5%,start line:89% size:57.5% is the timing. 23:39.033 --> 23:42.833 align:left position:12.5%,start line:83% size:77.5% Either children see all objects simultaneously, 23:42.933 --> 23:45.533 align:left position:20%,start line:83% size:70% preventing forgetting, or they see them one at a time. 23:45.633 --> 23:47.066 align:left position:27.5%,start line:83% size:62.5% And what the spaced condition does 23:47.166 --> 23:49.333 align:left position:20%,start line:83% size:70% is it introduces the most forgetting during learning 23:49.433 --> 23:51.833 align:left position:22.5%,start line:83% size:67.5% because there are those 30-second intervals 23:51.933 --> 23:53.733 align:left position:20%,start line:89% size:70% between each presentation 23:53.833 --> 23:56.466 align:left position:22.5%,start line:83% size:67.5% that gives children the opportunity to forget 23:56.566 --> 23:58.633 align:left position:22.5%,start line:89% size:67.5% in between each object. 23:58.733 --> 24:00.966 align:left position:27.5%,start line:83% size:62.5% And so they have to think harder and harder 24:01.066 --> 24:03.766 align:left position:17.5%,start line:83% size:72.5% about what they saw earlier in order to abstract 24:03.866 --> 24:07.200 align:left position:17.5%,start line:83% size:72.5% the relevant and irrelevant features of the category wug. 24:09.000 --> 24:12.833 align:left position:15%,start line:5% size:75% Children were also presented with a distractor item 24:12.933 --> 24:16.033 align:left position:20%,start line:5% size:70% during learning, and the experimenter did not label this. 24:16.133 --> 24:17.433 align:left position:32.5%,start line:5% size:57.5% They would say, "Look at this toy." 24:17.533 --> 24:20.100 align:left position:15%,start line:5% size:75% And it was presented for the same amount of time 24:20.200 --> 24:23.400 align:left position:17.5%,start line:5% size:72.5% as the objects, 40 seconds. 24:23.500 --> 24:27.100 align:left position:27.5%,start line:5% size:62.5% And then there was either a immediate test 24:27.200 --> 24:30.800 align:left position:20%,start line:5% size:70% or a test after a delay, a 15-minute delay. 24:30.900 --> 24:33.933 align:left position:22.5%,start line:5% size:67.5% And the reason for this difference across conditions 24:34.033 --> 24:35.133 align:left position:17.5%,start line:5% size:72.5% is that we were interested 24:35.233 --> 24:37.233 align:left position:22.5%,start line:5% size:67.5% in not only forgetting during learning, 24:37.333 --> 24:39.200 align:left position:15%,start line:71% size:75% that's those three conditions I showed you earlier, 24:39.300 --> 24:41.166 align:left position:30%,start line:71% size:60% but we were also interested in forgetting 24:41.266 --> 24:43.300 align:left position:17.5%,start line:71% size:72.5% between learning and test. 24:43.400 --> 24:46.966 align:left position:17.5%,start line:71% size:72.5% And so immediate condition prevents forgetting 24:47.066 --> 24:48.733 align:left position:32.5%,start line:71% size:57.5% from happening between learning and test, 24:48.833 --> 24:52.466 align:left position:10%,start line:71% size:80% and a 15-minute delay introduces the opportunity of forgetting 24:52.566 --> 24:56.900 align:left position:25%,start line:71% size:65% between the immediate and delayed test. 24:57.000 --> 24:59.066 align:left position:12.5%,start line:71% size:77.5% So we're introducing forgetting 24:59.166 --> 25:02.133 align:left position:22.5%,start line:71% size:67.5% at different levels of the learning process. 25:02.233 --> 25:04.100 align:left position:22.5%,start line:5% size:67.5% And then the test item was very similar 25:04.200 --> 25:05.733 align:left position:15%,start line:5% size:75% to what I showed you earlier. 25:05.833 --> 25:08.633 align:left position:17.5%,start line:5% size:72.5% Children would be presented with four objects, 25:08.733 --> 25:11.433 align:left position:27.5%,start line:5% size:62.5% and then it was the child's job to pick out 25:11.533 --> 25:13.900 align:left position:10%,start line:5% size:80% a novel instance of the category that they learned about. 25:14.000 --> 25:16.733 align:left position:12.5%,start line:5% size:77.5% So the experimenter would say, "Can you hand me the wug?" 25:16.833 --> 25:18.800 align:left position:20%,start line:5% size:70% And it's the child's job to pick up the wug 25:18.900 --> 25:21.800 align:left position:25%,start line:5% size:65% and place it into the experimenter's hand. 25:23.733 --> 25:27.866 align:left position:17.5%,start line:5% size:72.5% Okay, what I'm going to do is show you some results. 25:28.866 --> 25:30.500 align:left position:27.5%,start line:5% size:62.5% This is the results of Experiment 1. 25:30.600 --> 25:34.333 align:left position:15%,start line:5% size:75% And what you're seeing on the X-axis is the testing delay. 25:34.433 --> 25:37.100 align:left position:20%,start line:5% size:70% So either children being tested immediately, 25:37.200 --> 25:40.066 align:left position:25%,start line:5% size:65% or a 15-minute delay, 25:40.166 --> 25:42.933 align:left position:15%,start line:5% size:75% and then on the Y-axis is the number of correct responses. 25:43.033 --> 25:45.066 align:left position:17.5%,start line:5% size:72.5% So this is the mean number of times 25:45.166 --> 25:49.533 align:left position:12.5%,start line:5% size:77.5% that children correctly handed the wug to the experimenter. 25:51.033 --> 25:53.833 align:left position:22.5%,start line:5% size:67.5% So here's what we found at the immediate test. 25:53.933 --> 25:55.933 align:left position:32.5%,start line:5% size:57.5% Children in the simultaneous condition 25:56.033 --> 25:58.166 align:left position:35%,start line:5% size:55% significantly outperformed children 25:58.266 --> 26:00.700 align:left position:25%,start line:5% size:65% in the massed and the spaced conditions. 26:01.700 --> 26:03.566 align:left position:25%,start line:5% size:65% So if Ernie Rothkopf were here, he would say, 26:03.666 --> 26:05.066 align:left position:30%,start line:5% size:60% "Look, I'm right. 26:05.166 --> 26:07.766 align:left position:17.5%,start line:5% size:72.5% "The condition that had the least amount of forgetting 26:07.866 --> 26:09.733 align:left position:17.5%,start line:5% size:72.5% led to the most learning." 26:09.833 --> 26:12.333 align:left position:22.5%,start line:5% size:67.5% 'Cause the simultaneous condition at the immediate test 26:12.433 --> 26:15.800 align:left position:15%,start line:5% size:75% introduced no learning or no forgetting during learning, 26:15.900 --> 26:18.500 align:left position:22.5%,start line:5% size:67.5% but also no forgetting between learning and test. 26:18.600 --> 26:21.133 align:left position:17.5%,start line:71% size:72.5% So this would sort of prove Ernie and others right 26:21.233 --> 26:25.500 align:left position:17.5%,start line:71% size:72.5% that forgetting does deter conceptual development. 26:25.600 --> 26:30.600 align:left position:12.5%,start line:71% size:77.5% However, let's look at the data from the 15-minute delay. 26:31.800 --> 26:33.400 align:left position:22.5%,start line:5% size:67.5% What we observed at the 15-minute delay 26:33.500 --> 26:35.400 align:left position:22.5%,start line:5% size:67.5% is that children in the spaced condition 26:35.500 --> 26:37.300 align:left position:35%,start line:5% size:55% significantly outperformed children 26:37.400 --> 26:39.733 align:left position:27.5%,start line:5% size:62.5% in the simultaneous and massed conditions. 26:40.733 --> 26:41.866 align:left position:17.5%,start line:5% size:72.5% And you might wonder here, 26:41.966 --> 26:43.633 align:left position:30%,start line:5% size:60% "Well, wow, this is an interaction, 26:43.733 --> 26:45.700 align:left position:22.5%,start line:5% size:67.5% "a completely different pattern of results 26:45.800 --> 26:47.566 align:left position:25%,start line:5% size:65% of the delayed test." 26:47.666 --> 26:49.166 align:left position:15%,start line:5% size:75% And indeed, what we see here 26:49.266 --> 26:52.666 align:left position:15%,start line:5% size:75% is children that had the most opportunities of forgetting 26:52.766 --> 26:56.200 align:left position:15%,start line:5% size:75% perform the highest, because indeed the 15-minute delay 26:56.300 --> 26:57.433 align:left position:27.5%,start line:5% size:62.5% was the most amount of forgetting 26:57.533 --> 26:59.000 align:left position:17.5%,start line:5% size:72.5% between learning and test, 26:59.100 --> 27:01.566 align:left position:15%,start line:5% size:75% and then the spaced condition introduced forgetting 27:01.666 --> 27:03.900 align:left position:15%,start line:5% size:75% during the learning process. 27:04.000 --> 27:08.000 align:left position:15%,start line:71% size:75% So this is the exact opposite of what Ernie would predict. 27:08.100 --> 27:10.233 align:left position:27.5%,start line:71% size:62.5% Here what we see is that forgetting might be 27:10.333 --> 27:13.633 align:left position:20%,start line:71% size:70% facilitating abstraction and generalization. 27:15.133 --> 27:19.166 align:left position:25%,start line:71% size:65% I'm going to jump to Experiment 2 quickly 27:19.266 --> 27:22.266 align:left position:25%,start line:71% size:65% and just explain why we did Experiment 2. 27:22.366 --> 27:23.433 align:left position:27.5%,start line:71% size:62.5% So in Experiment 2, 27:23.533 --> 27:25.466 align:left position:22.5%,start line:71% size:67.5% what we were interested in is we said, 27:25.566 --> 27:27.666 align:left position:25%,start line:71% size:65% "Well, we think that forgetting is happening 27:27.766 --> 27:29.433 align:left position:20%,start line:71% size:70% between learning events." 27:29.533 --> 27:32.866 align:left position:20%,start line:71% size:70% In other words, we think that these 30-second gaps 27:32.966 --> 27:35.866 align:left position:20%,start line:71% size:70% introduced opportunities for children to forget. 27:35.966 --> 27:38.266 align:left position:17.5%,start line:71% size:72.5% But what we wanted to know is we wanted to have data 27:38.366 --> 27:41.166 align:left position:20%,start line:71% size:70% to actually show that the forgetting is happening. 27:41.266 --> 27:43.433 align:left position:27.5%,start line:71% size:62.5% So what we decided to do in Experiment 2 27:43.533 --> 27:48.300 align:left position:17.5%,start line:71% size:72.5% is ask children to retrieve their learning during learning. 27:48.400 --> 27:49.800 align:left position:17.5%,start line:5% size:72.5% And here's how we did this. 27:49.900 --> 27:52.000 align:left position:12.5%,start line:5% size:77.5% So imagine children are in the simultaneous condition, 27:52.100 --> 27:55.766 align:left position:15%,start line:5% size:75% they have four objects put on the table at the same time. 27:55.866 --> 27:58.366 align:left position:17.5%,start line:5% size:72.5% And the experimenter would label the first object and say, 27:58.466 --> 28:00.166 align:left position:22.5%,start line:5% size:67.5% "Look, this is a wug." 28:00.266 --> 28:03.266 align:left position:12.5%,start line:5% size:77.5% Wait 10 seconds and then point to the second object and say, 28:03.366 --> 28:04.533 align:left position:22.5%,start line:5% size:67.5% "What is this called?" 28:05.533 --> 28:06.700 align:left position:15%,start line:5% size:75% They would wait five seconds, 28:06.800 --> 28:08.733 align:left position:22.5%,start line:5% size:67.5% and then regardless of what the children said, 28:08.833 --> 28:11.400 align:left position:17.5%,start line:5% size:72.5% the experimenter would say, "This is a wug." 28:11.500 --> 28:13.200 align:left position:25%,start line:5% size:65% And then they'd move on to the third object, 28:13.300 --> 28:15.866 align:left position:12.5%,start line:5% size:77.5% and they point to it and they'd say, "What is this called?" 28:15.966 --> 28:17.100 align:left position:20%,start line:5% size:70% They'd wait five seconds, 28:17.200 --> 28:18.966 align:left position:22.5%,start line:5% size:67.5% and then regardless of what the child said, 28:19.066 --> 28:20.633 align:left position:15%,start line:5% size:75% they'd say, "This is a wug." 28:20.733 --> 28:23.300 align:left position:30%,start line:5% size:60% And they did that for all four objects. 28:23.400 --> 28:25.166 align:left position:32.5%,start line:5% size:57.5% The same thing happened in the massed 28:25.266 --> 28:26.766 align:left position:20%,start line:5% size:70% and the spaced condition. 28:26.866 --> 28:28.600 align:left position:25%,start line:5% size:65% Children would hear, "This is a wug," 28:28.700 --> 28:29.966 align:left position:17.5%,start line:5% size:72.5% on the first presentation. 28:30.066 --> 28:31.633 align:left position:32.5%,start line:5% size:57.5% And then on the subsequent presentations, 28:31.733 --> 28:33.900 align:left position:22.5%,start line:5% size:67.5% the experimenter would first prompt the children 28:34.000 --> 28:36.833 align:left position:15%,start line:5% size:75% to report the word by saying, "What is this called?" 28:36.933 --> 28:40.600 align:left position:25%,start line:5% size:65% Wait five seconds and then say, "This is a wug." 28:40.700 --> 28:42.500 align:left position:15%,start line:71% size:75% And what these retrievals did 28:42.600 --> 28:45.466 align:left position:22.5%,start line:71% size:67.5% is it gives us a sense of how readily children 28:45.566 --> 28:47.866 align:left position:17.5%,start line:71% size:72.5% are retrieving information during learning. 28:48.866 --> 28:49.933 align:left position:25%,start line:71% size:65% And what we predicted 28:50.033 --> 28:51.666 align:left position:22.5%,start line:71% size:67.5% is that children in the spaced learning condition 28:51.766 --> 28:54.133 align:left position:30%,start line:71% size:60% would demonstrate the most forgetting 28:54.233 --> 28:56.333 align:left position:30%,start line:71% size:60% because of those 30-second intervals. 28:57.866 --> 29:01.433 align:left position:22.5%,start line:5% size:67.5% Okay, here's some data comparing the final test 29:01.533 --> 29:04.400 align:left position:30%,start line:5% size:60% from Experiment 1 and Experiment 2. 29:04.500 --> 29:07.066 align:left position:22.5%,start line:5% size:67.5% And what you can see is we observe the same pattern 29:07.166 --> 29:08.633 align:left position:12.5%,start line:5% size:77.5% of results across experiments. 29:08.733 --> 29:11.233 align:left position:20%,start line:5% size:70% The bars are a little bit higher in Experiment 2. 29:11.333 --> 29:12.666 align:left position:22.5%,start line:5% size:67.5% This is to be expected. 29:12.766 --> 29:15.433 align:left position:20%,start line:5% size:70% It's because children are getting more retrieval practice 29:15.533 --> 29:18.033 align:left position:27.5%,start line:5% size:62.5% by us asking them, "What is this called?" 29:18.133 --> 29:19.733 align:left position:12.5%,start line:5% size:77.5% And so they overall did better, 29:19.833 --> 29:22.333 align:left position:25%,start line:5% size:65% basically a retrieval practice effect here, 29:22.433 --> 29:25.000 align:left position:15%,start line:5% size:75% but we see the same pattern, that at the immediate test, 29:25.100 --> 29:27.500 align:left position:20%,start line:5% size:70% children do better in the simultaneous condition, 29:27.600 --> 29:29.033 align:left position:20%,start line:5% size:70% but at the delayed test, 29:29.133 --> 29:31.133 align:left position:25%,start line:5% size:65% they do better in the spaced condition. 29:33.000 --> 29:36.633 align:left position:22.5%,start line:5% size:67.5% Here, what you're going to see are three bars 29:36.733 --> 29:39.266 align:left position:20%,start line:5% size:70% representing the overall retrieval successes 29:39.366 --> 29:42.166 align:left position:15%,start line:5% size:75% in the simultaneous, massed, and spaced conditions. 29:42.266 --> 29:43.766 align:left position:22.5%,start line:5% size:67.5% So that's what will be on the X-axis. 29:43.866 --> 29:45.266 align:left position:22.5%,start line:5% size:67.5% And then on the Y-axis, 29:45.366 --> 29:48.366 align:left position:17.5%,start line:5% size:72.5% what you'll see is the mean number of retrieval successes 29:48.466 --> 29:49.733 align:left position:37.5%,start line:5% size:52.5% out of 24. 29:49.833 --> 29:52.033 align:left position:17.5%,start line:5% size:72.5% So there were eight trials with three retrieval attempts 29:52.133 --> 29:54.966 align:left position:12.5%,start line:5% size:77.5% on each, so that adds up to 24. 29:55.066 --> 29:56.566 align:left position:25%,start line:5% size:65% Here's what we found. 29:56.666 --> 29:59.966 align:left position:20%,start line:5% size:70% We found that children in the simultaneous condition 30:00.066 --> 30:01.966 align:left position:30%,start line:5% size:60% had significantly higher performance 30:02.066 --> 30:04.133 align:left position:25%,start line:5% size:65% than children in the massed condition. 30:04.233 --> 30:05.933 align:left position:17.5%,start line:5% size:72.5% And we found that children in the massed condition 30:06.033 --> 30:07.600 align:left position:30%,start line:5% size:60% had significantly higher performance 30:07.700 --> 30:10.066 align:left position:25%,start line:5% size:65% than children in the spaced condition. 30:10.166 --> 30:12.033 align:left position:27.5%,start line:5% size:62.5% And this is exactly what we predicted. 30:12.133 --> 30:13.600 align:left position:32.5%,start line:5% size:57.5% Children in the simultaneous condition 30:13.700 --> 30:15.333 align:left position:15%,start line:5% size:75% are having a lot easier time 30:15.433 --> 30:17.633 align:left position:25%,start line:5% size:65% retrieving the label for the category 30:17.733 --> 30:20.466 align:left position:10%,start line:5% size:80% because they're not experiencing the same degree of forgetting 30:20.566 --> 30:23.066 align:left position:20%,start line:5% size:70% as children in the massed or spaced conditions. 30:23.166 --> 30:25.900 align:left position:25%,start line:5% size:65% And indeed, children in the spaced condition 30:26.000 --> 30:28.433 align:left position:20%,start line:5% size:70% are struggling the most. 30:28.533 --> 30:32.666 align:left position:22.5%,start line:5% size:67.5% We took this same data and we plotted it by time. 30:32.766 --> 30:34.966 align:left position:22.5%,start line:5% size:67.5% And just as a reminder, 30:35.066 --> 30:37.533 align:left position:30%,start line:5% size:60% what we did is we had Retrieval 1 30:37.633 --> 30:39.900 align:left position:10%,start line:5% size:80% be at the second learning event, 30:40.000 --> 30:42.466 align:left position:22.5%,start line:5% size:67.5% Retrieval 2 was at the third learning event, 30:42.566 --> 30:44.800 align:left position:17.5%,start line:5% size:72.5% and Retrieval 3 was at the fourth learning event, 30:44.900 --> 30:46.066 align:left position:25%,start line:5% size:65% 'cause on that first learning event, 30:46.166 --> 30:47.233 align:left position:22.5%,start line:5% size:67.5% we labeled the object. 30:47.333 --> 30:48.433 align:left position:20%,start line:5% size:70% We said, "This is a wug." 30:48.533 --> 30:50.233 align:left position:27.5%,start line:5% size:62.5% And then asked them what it was called 30:50.333 --> 30:51.566 align:left position:15%,start line:5% size:75% on subsequent learning event. 30:51.666 --> 30:53.566 align:left position:22.5%,start line:5% size:67.5% So on the X-axis, what you're seeing here 30:53.666 --> 30:55.833 align:left position:15%,start line:5% size:75% is retrieval attempt 1, 2, 3, 30:55.933 --> 30:59.600 align:left position:25%,start line:5% size:65% which corresponds to learning 2, 3, and 4. 30:59.700 --> 31:03.400 align:left position:20%,start line:5% size:70% And we wanted to know if the nature of retrieval 31:03.500 --> 31:06.500 align:left position:27.5%,start line:5% size:62.5% changed across the learning phase. 31:06.600 --> 31:08.233 align:left position:10%,start line:5% size:80% So what you're seeing here first 31:08.333 --> 31:10.933 align:left position:22.5%,start line:5% size:67.5% is performance for the simultaneous condition. 31:11.033 --> 31:13.200 align:left position:25%,start line:5% size:65% And what you see as a relatively flat line 31:13.300 --> 31:15.500 align:left position:30%,start line:5% size:60% across the three retrieval tasks. 31:15.600 --> 31:17.433 align:left position:22.5%,start line:5% size:67.5% And what this suggests is that children 31:17.533 --> 31:19.266 align:left position:15%,start line:5% size:75% in the simultaneous condition 31:19.366 --> 31:21.700 align:left position:25%,start line:5% size:65% are observing overall high performance 31:21.800 --> 31:24.766 align:left position:20%,start line:5% size:70% that doesn't change much across the learning phase. 31:25.800 --> 31:27.366 align:left position:10%,start line:5% size:80% The next line that you're seeing 31:27.466 --> 31:29.233 align:left position:25%,start line:5% size:65% is performance in the massed condition. 31:29.333 --> 31:30.566 align:left position:22.5%,start line:5% size:67.5% It's a similar pattern 31:30.666 --> 31:32.900 align:left position:27.5%,start line:5% size:62.5% to children in the simultaneous condition, 31:33.000 --> 31:34.066 align:left position:30%,start line:5% size:60% it's just lower. 31:34.166 --> 31:35.400 align:left position:15%,start line:5% size:75% So it's a little bit harder, 31:35.500 --> 31:37.100 align:left position:25%,start line:5% size:65% but there's no change during learning 31:37.200 --> 31:39.466 align:left position:27.5%,start line:5% size:62.5% for children in the massed condition. 31:39.566 --> 31:42.166 align:left position:20%,start line:5% size:70% However, we see something fundamentally different 31:42.266 --> 31:43.900 align:left position:20%,start line:5% size:70% in the spaced condition. 31:44.000 --> 31:46.500 align:left position:17.5%,start line:5% size:72.5% What we observe is that the first retrieval attempt, 31:46.600 --> 31:49.300 align:left position:20%,start line:5% size:70% children really struggle to retrieve information. 31:49.400 --> 31:52.600 align:left position:12.5%,start line:5% size:77.5% In fact, it's not significantly different than zero. 31:52.700 --> 31:54.033 align:left position:15%,start line:5% size:75% So essentially, when children 31:54.133 --> 31:55.533 align:left position:27.5%,start line:5% size:62.5% get to that second retrieval attempt, 31:55.633 --> 31:57.033 align:left position:27.5%,start line:5% size:62.5% they kind of stare at the experimenter 31:57.133 --> 31:58.433 align:left position:10%,start line:5% size:80% and they don't know what to say. 31:58.533 --> 32:01.766 align:left position:30%,start line:5% size:60% They're unable to produce the word wug. 32:01.866 --> 32:05.533 align:left position:15%,start line:5% size:75% However, across the learning phase, we observed performance. 32:05.633 --> 32:09.866 align:left position:15%,start line:5% size:75% So they get better and better at retrieving the word wug 32:09.966 --> 32:11.633 align:left position:30%,start line:5% size:60% during learning. 32:11.733 --> 32:14.633 align:left position:20%,start line:71% size:70% So what this data does is it confirms our hypothesis 32:14.733 --> 32:17.166 align:left position:27.5%,start line:71% size:62.5% that this paradigm does introduce 32:17.266 --> 32:19.966 align:left position:27.5%,start line:71% size:62.5% different levels of forgetting during learning, 32:20.066 --> 32:22.666 align:left position:15%,start line:71% size:75% but what this data also does is it provides evidence 32:22.766 --> 32:25.400 align:left position:22.5%,start line:71% size:67.5% for a theoretical count that explains 32:25.500 --> 32:27.933 align:left position:30%,start line:71% size:60% why forgetting is promoting learning. 32:28.033 --> 32:30.866 align:left position:30%,start line:71% size:60%   And what we have argued is that forgetting 32:30.966 --> 32:34.566 align:left position:20%,start line:83% size:70% is a form of abstraction, forgetting acts as abstraction 32:34.666 --> 32:37.633 align:left position:27.5%,start line:83% size:62.5% in order to promote conceptual development. 32:37.733 --> 32:40.233 align:left position:27.5%,start line:83% size:62.5% So I wanna walk you through now how this works. 32:41.233 --> 32:42.466 align:left position:12.5%,start line:5% size:77.5% So imagine that you're a child 32:42.566 --> 32:46.066 align:left position:15%,start line:5% size:75% and you're seeing a wug or a new toy for the first time. 32:46.166 --> 32:47.266 align:left position:12.5%,start line:5% size:77.5% Well, you're gonna see that wug 32:47.366 --> 32:48.733 align:left position:22.5%,start line:5% size:67.5% and you're immediately gonna forget 32:48.833 --> 32:50.066 align:left position:20%,start line:5% size:70% everything about that wug 32:50.166 --> 32:51.933 align:left position:30%,start line:5% size:60% according to the curvilinear pattern 32:52.033 --> 32:53.533 align:left position:17.5%,start line:5% size:72.5% that I showed you earlier. 32:53.633 --> 32:55.566 align:left position:20%,start line:5% size:70% And here, what we see is that forgetting curve. 32:56.566 --> 32:57.733 align:left position:25%,start line:5% size:65% So you'll see a wug, 32:57.833 --> 32:59.566 align:left position:25%,start line:5% size:65% and a certain amount of time will go on, 32:59.666 --> 33:01.900 align:left position:30%,start line:5% size:60% and you will then experience another wug 33:02.000 --> 33:05.333 align:left position:22.5%,start line:5% size:67.5% or another new toy that shares the category label. 33:05.433 --> 33:08.866 align:left position:25%,start line:5% size:65% And what will happen is that that new wug 33:08.966 --> 33:12.733 align:left position:15%,start line:5% size:75% will prompt you to recollect information that is similar 33:12.833 --> 33:15.500 align:left position:27.5%,start line:5% size:62.5% to the information that you saw earlier. 33:15.600 --> 33:16.800 align:left position:30%,start line:5% size:60% So in this case, 33:16.900 --> 33:21.400 align:left position:15%,start line:5% size:75% what is similar across these two items is their shape. 33:21.500 --> 33:24.066 align:left position:20%,start line:5% size:70% And so what you'll do is you'll retrieve the shape 33:24.166 --> 33:26.966 align:left position:25%,start line:5% size:65% that you saw earlier and you'll engage 33:27.066 --> 33:28.800 align:left position:15%,start line:5% size:75% in cognitive effort doing so 33:28.900 --> 33:30.800 align:left position:32.5%,start line:5% size:57.5% because you've forgotten about it. 33:30.900 --> 33:32.600 align:left position:27.5%,start line:5% size:62.5% And so you have to dig through your mind 33:32.700 --> 33:35.766 align:left position:20%,start line:5% size:70% to find that information, that past memory. 33:35.866 --> 33:37.600 align:left position:35%,start line:5% size:55% And what that cognitive effort does 33:37.700 --> 33:41.800 align:left position:32.5%,start line:5% size:57.5% is it slows the memory for shape, 33:41.900 --> 33:45.133 align:left position:22.5%,start line:5% size:67.5% which in this category is the relevant feature. 33:45.233 --> 33:47.900 align:left position:22.5%,start line:5% size:67.5% Now that second object won't cue you to recall 33:48.000 --> 33:49.166 align:left position:17.5%,start line:5% size:72.5% other types of information, 33:49.266 --> 33:51.666 align:left position:25%,start line:5% size:65% like the color or the texture of the object 33:51.766 --> 33:52.833 align:left position:25%,start line:5% size:65% that you saw earlier, 33:52.933 --> 33:55.866 align:left position:25%,start line:5% size:65% because there isn't a match across the items. 33:55.966 --> 33:58.300 align:left position:22.5%,start line:5% size:67.5% And so what that means is that you'll continue 33:58.400 --> 34:00.833 align:left position:32.5%,start line:5% size:57.5% to forget that irrelevant information, 34:00.933 --> 34:05.066 align:left position:20%,start line:5% size:70% the texture and the color at the same rate as earlier, 34:05.166 --> 34:07.366 align:left position:27.5%,start line:5% size:62.5% when you first saw the original wug. 34:08.366 --> 34:11.666 align:left position:20%,start line:5% size:70% And what you can see from looking at this image is now 34:11.766 --> 34:13.133 align:left position:30%,start line:5% size:60% there's different forgetting rates 34:13.233 --> 34:15.100 align:left position:12.5%,start line:5% size:77.5% for information that's relevant 34:15.200 --> 34:17.833 align:left position:32.5%,start line:5% size:57.5% and information that's irrelevant. 34:18.833 --> 34:20.333 align:left position:30%,start line:5% size:60% Let's do another demonstration of this. 34:20.433 --> 34:23.800 align:left position:30%,start line:5% size:60% So let's just say that more time goes on 34:23.900 --> 34:27.233 align:left position:30%,start line:5% size:60% and a child then sees yet another wug. 34:28.233 --> 34:30.366 align:left position:22.5%,start line:5% size:67.5% And what that third wug is gonna do 34:30.466 --> 34:32.800 align:left position:27.5%,start line:5% size:62.5% is prompt children to recall information 34:32.900 --> 34:35.966 align:left position:15%,start line:5% size:75% from the first and second wug that's similar to that item. 34:36.066 --> 34:38.966 align:left position:22.5%,start line:5% size:67.5% And again, that similar feature is shape. 34:39.066 --> 34:40.200 align:left position:15%,start line:5% size:75% And so what children will do 34:40.300 --> 34:42.500 align:left position:30%,start line:5% size:60% is they'll engage in cognitive effort, 34:42.600 --> 34:44.766 align:left position:27.5%,start line:5% size:62.5% searching for that shape information. 34:44.866 --> 34:47.433 align:left position:12.5%,start line:5% size:77.5% And what that cognitive effort will translate into 34:47.533 --> 34:51.833 align:left position:22.5%,start line:5% size:67.5% is a slowed forgetting for that feature shape. 34:51.933 --> 34:54.733 align:left position:22.5%,start line:5% size:67.5% So it's again, slowing the forgetting. 34:54.833 --> 34:57.833 align:left position:30%,start line:5% size:60% However, features like color and texture 34:57.933 --> 34:59.566 align:left position:15%,start line:5% size:75% are continuing to be forgot, 34:59.666 --> 35:03.000 align:left position:30%,start line:5% size:60% according to that original forgetting curve. 35:03.100 --> 35:07.033 align:left position:17.5%,start line:5% size:72.5% So they're being forgotten at a much different rate 35:07.133 --> 35:08.833 align:left position:12.5%,start line:5% size:77.5% than the relevant information. 35:09.833 --> 35:12.933 align:left position:12.5%,start line:71% size:77.5% And what we hypothesize happens across early development 35:13.033 --> 35:15.633 align:left position:17.5%,start line:71% size:72.5% or learning about something new for the first time 35:15.733 --> 35:18.800 align:left position:27.5%,start line:71% size:62.5% is this process of where we continually 35:18.900 --> 35:22.366 align:left position:25%,start line:71% size:65% re-retrieve relevant information in the world 35:22.466 --> 35:25.866 align:left position:15%,start line:71% size:75% and then we don't re-retrieve irrelevant information 35:25.966 --> 35:27.200 align:left position:35%,start line:71% size:55% in the world. 35:27.300 --> 35:30.533 align:left position:17.5%,start line:5% size:72.5% And as this process happens over and over and over again, 35:30.633 --> 35:34.100 align:left position:20%,start line:5% size:70% we end up with different forgetting curves 35:34.200 --> 35:36.133 align:left position:12.5%,start line:5% size:77.5% for information that's relevant 35:36.233 --> 35:38.700 align:left position:32.5%,start line:5% size:57.5% and information that's irrelevant. 35:38.800 --> 35:41.333 align:left position:27.5%,start line:5% size:62.5% And so by the time children or adults 35:41.433 --> 35:46.300 align:left position:25%,start line:5% size:65% need to generalize to something new in that category, 35:46.400 --> 35:49.733 align:left position:22.5%,start line:5% size:67.5% they will more readily retrieve relevant information 35:49.833 --> 35:52.666 align:left position:22.5%,start line:5% size:67.5% like shape, compared to irrelevant information 35:52.766 --> 35:54.566 align:left position:22.5%,start line:5% size:67.5% like color and texture. 35:54.666 --> 35:57.133 align:left position:25%,start line:5% size:65% And this will support generalization 35:57.233 --> 35:58.466 align:left position:17.5%,start line:5% size:72.5% and conceptual development 35:58.566 --> 36:01.966 align:left position:15%,start line:5% size:75% because they're re-retrieving what's important 36:02.066 --> 36:05.566 align:left position:25%,start line:5% size:65% and then applying it to that new category. 36:05.666 --> 36:08.933 align:left position:22.5%,start line:5% size:67.5% So in other words, it's helping children, adults, 36:09.033 --> 36:12.133 align:left position:17.5%,start line:5% size:72.5% everyone to abstract what's relevant in the world, 36:12.233 --> 36:16.800 align:left position:17.5%,start line:5% size:72.5% and therefore helping us to learn categories and concepts. 36:18.833 --> 36:20.200 align:left position:20%,start line:89% size:70% Just as a quick summary. 36:21.200 --> 36:25.033 align:left position:22.5%,start line:83% size:67.5% For a long time, going back to the 1800s, 36:25.133 --> 36:27.500 align:left position:22.5%,start line:83% size:67.5% researchers and general intuition told us 36:27.600 --> 36:30.500 align:left position:15%,start line:83% size:75% that forgetting should deter conceptual development. 36:30.600 --> 36:32.966 align:left position:20%,start line:83% size:70% It should prevent us from abstracting what's relevant 36:33.066 --> 36:35.200 align:left position:15%,start line:89% size:75% and irrelevant in the world. 36:35.300 --> 36:38.900 align:left position:22.5%,start line:83% size:67.5% However, my lab's work has shown the opposite: 36:39.000 --> 36:42.000 align:left position:15%,start line:83% size:75% that forgetting can actually act as a form of abstraction, 36:42.100 --> 36:45.000 align:left position:25%,start line:83% size:65% speed up abstraction, and help us to learn 36:45.100 --> 36:47.866 align:left position:15%,start line:89% size:75% new categories and concepts. 36:47.966 --> 36:50.600 align:left position:10%,start line:71% size:80% And so while we've always agreed 36:50.700 --> 36:53.333 align:left position:20%,start line:71% size:70% that forgetting can help learning and memory, 36:53.433 --> 36:55.700 align:left position:22.5%,start line:71% size:67.5% we now know that it can help us think and develop 36:55.800 --> 36:58.033 align:left position:25%,start line:71% size:65% our most higher order forms of learning, 36:58.133 --> 37:01.433 align:left position:15%,start line:71% size:75% like learning a new language or learning complex concepts. 37:02.966 --> 37:04.433 align:left position:15%,start line:71% size:75% So that's the silver lining, 37:04.533 --> 37:08.700 align:left position:12.5%,start line:71% size:77.5% is that even though forgetting is inevitable and predictable 37:08.800 --> 37:11.066 align:left position:20%,start line:71% size:70% and will prevent us from remembering information, 37:11.166 --> 37:12.466 align:left position:20%,start line:71% size:70% it's also gonna help us. 37:12.566 --> 37:14.600 align:left position:27.5%,start line:71% size:62.5% It's gonna help us remember what's important 37:14.700 --> 37:17.533 align:left position:20%,start line:71% size:70% so that we can generalize across our experiences 37:17.633 --> 37:19.666 align:left position:35%,start line:71% size:55% based on the important information. 37:21.633 --> 37:23.600 align:left position:35%,start line:71% size:55%   So I have a number of concluding thoughts 37:23.700 --> 37:25.733 align:left position:22.5%,start line:83% size:67.5% that I'd like to share with you all. 37:25.833 --> 37:27.500 align:left position:15%,start line:89% size:75% The first concluding thought 37:27.600 --> 37:30.600 align:left position:22.5%,start line:83% size:67.5% is to share some of the exciting work that we're doing, 37:30.700 --> 37:33.633 align:left position:20%,start line:83% size:70% trying to build off this basic research 37:33.733 --> 37:35.933 align:left position:22.5%,start line:83% size:67.5% to design interventions for children. 37:36.933 --> 37:38.833 align:left position:22.5%,start line:71% size:67.5% One of the things that we've done is we've thought, 37:38.933 --> 37:43.233 align:left position:15%,start line:71% size:75% "Well, why don't we integrate forgetting into curriculum?" 37:43.333 --> 37:46.300 align:left position:20%,start line:71% size:70% In other words, we should work with teachers and parents 37:46.400 --> 37:48.766 align:left position:32.5%,start line:71% size:57.5% in order to get them to encourage 37:48.866 --> 37:50.800 align:left position:20%,start line:71% size:70% their children to forget. 37:50.900 --> 37:53.400 align:left position:22.5%,start line:71% size:67.5% Now, I know this sounds very counterintuitive 37:53.500 --> 37:56.333 align:left position:20%,start line:71% size:70% because wow, teachers are trying to help kids remember, 37:56.433 --> 37:58.133 align:left position:25%,start line:71% size:65% parents are trying to help kids remember. 37:58.233 --> 38:02.266 align:left position:20%,start line:71% size:70% But remember, forgetting can help us to remember. 38:02.366 --> 38:04.400 align:left position:20%,start line:71% size:70% So what we've been doing is we've been working 38:04.500 --> 38:06.533 align:left position:15%,start line:71% size:75% with classrooms and teachers 38:06.633 --> 38:10.066 align:left position:22.5%,start line:71% size:67.5% and helping teachers to integrate spaced learning 38:10.166 --> 38:12.600 align:left position:22.5%,start line:71% size:67.5% into their curriculum. 38:12.700 --> 38:14.133 align:left position:22.5%,start line:71% size:67.5% Here's a quick example. 38:14.233 --> 38:17.133 align:left position:30%,start line:71% size:60% In a lot of early childhood curriculum, 38:17.233 --> 38:18.633 align:left position:27.5%,start line:71% size:62.5% teachers use units. 38:18.733 --> 38:22.100 align:left position:12.5%,start line:71% size:77.5% So they might have a lion month or a flower month, 38:22.200 --> 38:23.766 align:left position:32.5%,start line:71% size:57.5% where they talk about the same thing 38:23.866 --> 38:28.233 align:left position:20%,start line:71% size:70% in extensive conversation for a month and then move on. 38:28.333 --> 38:30.266 align:left position:22.5%,start line:71% size:67.5% So in other words, it's an immediate succession. 38:30.366 --> 38:32.600 align:left position:17.5%,start line:71% size:72.5% It's kind of like cramming. 38:32.700 --> 38:35.166 align:left position:17.5%,start line:71% size:72.5% So instead, what we've done is we've encouraged teachers 38:35.266 --> 38:38.766 align:left position:25%,start line:71% size:65% to distribute lessons out across time. 38:38.866 --> 38:40.633 align:left position:25%,start line:71% size:65%   We've done a series of experiments 38:40.733 --> 38:43.300 align:left position:15%,start line:83% size:75% to provide empirical evidence for teachers 38:43.400 --> 38:45.566 align:left position:10%,start line:89% size:80% that this is a good thing to do. 38:45.666 --> 38:48.166 align:left position:22.5%,start line:83% size:67.5% So for example, in some of our studies, 38:48.266 --> 38:50.566 align:left position:20%,start line:83% size:70% we come up with different learning schedules 38:50.666 --> 38:52.000 align:left position:22.5%,start line:89% size:67.5% for science curriculum. 38:52.100 --> 38:54.666 align:left position:25%,start line:83% size:65% And the example that I'm gonna show here 38:54.766 --> 38:58.400 align:left position:15%,start line:83% size:75% is the context of children's science curriculum 38:58.500 --> 39:00.466 align:left position:27.5%,start line:89% size:62.5% about food chains. 39:00.566 --> 39:03.066 align:left position:32.5%,start line:83% size:57.5% And food chains are a perfect context 39:03.166 --> 39:06.300 align:left position:17.5%,start line:83% size:72.5% because what teachers do is they introduce food chains 39:06.400 --> 39:07.866 align:left position:20%,start line:89% size:70% across different biomes. 39:07.966 --> 39:10.200 align:left position:20%,start line:71% size:70% So they'll introduce the food chain in the grasslands 39:10.300 --> 39:11.800 align:left position:25%,start line:71% size:65% and then the desert. 39:11.900 --> 39:13.400 align:left position:27.5%,start line:71% size:62.5% And then what they expect children to do 39:13.500 --> 39:16.933 align:left position:15%,start line:71% size:75% is to abstract out across all these different biomes 39:17.033 --> 39:19.566 align:left position:22.5%,start line:71% size:67.5% in order to generalize to a new biome, 39:19.666 --> 39:22.066 align:left position:15%,start line:71% size:75% like the Arctic or the swamp. 39:23.533 --> 39:26.200 align:left position:15%,start line:71% size:75% And so what we do is we work with classrooms and teachers 39:26.300 --> 39:29.400 align:left position:17.5%,start line:5% size:72.5% and develop a schedule such as the schedule you see here, 39:29.500 --> 39:32.433 align:left position:17.5%,start line:5% size:72.5% where there's one of three presentations options. 39:32.533 --> 39:36.533 align:left position:17.5%,start line:5% size:72.5% There's a massed schedule, a clumped schedule, 39:36.633 --> 39:38.600 align:left position:22.5%,start line:5% size:67.5% and a spaced schedule. 39:38.700 --> 39:40.600 align:left position:22.5%,start line:5% size:67.5% What you'll see in the massed schedule 39:40.700 --> 39:42.366 align:left position:32.5%,start line:5% size:57.5% is that lessons about food chains 39:42.466 --> 39:44.300 align:left position:35%,start line:5% size:55% are presented in immediate succession, 39:44.400 --> 39:47.933 align:left position:22.5%,start line:5% size:67.5% just like we do in the lab with the word lists. 39:48.033 --> 39:51.433 align:left position:25%,start line:5% size:65% The spaced condition distributes all the lessons 39:51.533 --> 39:53.000 align:left position:17.5%,start line:5% size:72.5% out across days of the week 39:53.100 --> 39:55.500 align:left position:27.5%,start line:5% size:62.5% so there's time in between each lesson, 39:55.600 --> 39:57.466 align:left position:27.5%,start line:5% size:62.5% which maps onto the spaced schedules 39:57.566 --> 39:59.166 align:left position:12.5%,start line:5% size:77.5% that we use in the lab as well. 40:00.166 --> 40:02.366 align:left position:20%,start line:5% size:70% In these studies, we use an intermediate condition 40:02.466 --> 40:03.700 align:left position:17.5%,start line:5% size:72.5% called the clump condition, 40:03.800 --> 40:06.733 align:left position:12.5%,start line:5% size:77.5% which introduces a combination of massing and spacing. 40:06.833 --> 40:08.866 align:left position:32.5%,start line:5% size:57.5% So some of the lessons are presented 40:08.966 --> 40:10.200 align:left position:20%,start line:5% size:70% in immediate succession, 40:10.300 --> 40:14.066 align:left position:20%,start line:5% size:70% whereas other lessons are distributed across time. 40:14.166 --> 40:17.966 align:left position:17.5%,start line:5% size:72.5% And we have each lesson be about the same amount of time, 40:18.066 --> 40:21.100 align:left position:17.5%,start line:5% size:72.5% so that we control for time across these experiments. 40:21.200 --> 40:24.433 align:left position:22.5%,start line:5% size:67.5% And we have a test for children that happens one week 40:24.533 --> 40:26.166 align:left position:22.5%,start line:5% size:67.5% after their last lesson 40:26.266 --> 40:30.800 align:left position:10%,start line:5% size:80% to understand what they remember from the varied conditions. 40:32.366 --> 40:34.666 align:left position:30%,start line:5% size:60% And I'm gonnashow you some data here, 40:34.766 --> 40:36.966 align:left position:30%,start line:5% size:60% where we had two different types of tests, 40:37.066 --> 40:41.266 align:left position:22.5%,start line:5% size:67.5% a simple generalization or simple concepts. 40:41.366 --> 40:43.833 align:left position:15%,start line:5% size:75% This is things like learning that bigger creatures 40:43.933 --> 40:46.366 align:left position:10%,start line:5% size:80% typically eat smaller creatures. 40:46.466 --> 40:49.700 align:left position:25%,start line:5% size:65% And then we also had some complex concepts. 40:49.800 --> 40:53.100 align:left position:10%,start line:5% size:80% And the idea that we tested here was the idea of interdependence. 40:53.200 --> 40:54.433 align:left position:27.5%,start line:5% size:62.5% So in other words, 40:54.533 --> 40:57.800 align:left position:20%,start line:5% size:70% if something happens to a particular creature in a biome, 40:57.900 --> 41:00.066 align:left position:27.5%,start line:5% size:62.5% it affects all the other creatures. 41:00.166 --> 41:04.433 align:left position:12.5%,start line:71% size:77.5% So for example, if there are no more fish in the ocean to eat, 41:04.533 --> 41:06.266 align:left position:25%,start line:71% size:65% that affects all the other creatures 41:06.366 --> 41:07.666 align:left position:22.5%,start line:71% size:67.5% that live in the ocean. 41:07.766 --> 41:10.066 align:left position:17.5%,start line:71% size:72.5% They will have less to eat because there are no more fish, 41:10.166 --> 41:13.766 align:left position:12.5%,start line:71% size:77.5% especially creatures higher up on the food chain. 41:14.766 --> 41:16.466 align:left position:25%,start line:71% size:65% So that's what you're gonna see on the X-axis. 41:16.566 --> 41:19.033 align:left position:32.5%,start line:5% size:57.5% On the Y-axis, what you're gonna see 41:19.133 --> 41:24.033 align:left position:15%,start line:5% size:75% is the difference between the pre-test and the post-test. 41:24.133 --> 41:28.066 align:left position:17.5%,start line:5% size:72.5% So we gave the tests before learning and after learning. 41:28.166 --> 41:31.633 align:left position:12.5%,start line:5% size:77.5% And what you'll see is for the simple generalization 41:31.733 --> 41:33.066 align:left position:22.5%,start line:5% size:67.5% or the simple concept, 41:33.166 --> 41:35.166 align:left position:22.5%,start line:5% size:67.5% we found that children in the spaced conditions 41:35.266 --> 41:37.966 align:left position:17.5%,start line:5% size:72.5% significantly outperformed children in the massed 41:38.066 --> 41:39.766 align:left position:17.5%,start line:5% size:72.5% and the clumped conditions. 41:39.866 --> 41:42.366 align:left position:15%,start line:5% size:75% And this is what we expected from prior research. 41:42.466 --> 41:45.366 align:left position:27.5%,start line:5% size:62.5% We expected to see this based off of 41:45.466 --> 41:48.100 align:left position:32.5%,start line:5% size:57.5% the relatively simple categories, 41:48.200 --> 41:50.933 align:left position:27.5%,start line:5% size:62.5% like the wugs that you saw earlier. 41:51.933 --> 41:54.166 align:left position:15%,start line:5% size:75% In this work, it was actually our first time testing 41:54.266 --> 41:57.000 align:left position:22.5%,start line:5% size:67.5% whether or not we would find this phenomenon 41:57.100 --> 42:01.733 align:left position:15%,start line:5% size:75% in a more complex task, like learning about interdependence, 42:01.833 --> 42:03.433 align:left position:10%,start line:5% size:80% but let me show you the results. 42:03.533 --> 42:04.766 align:left position:32.5%,start line:5% size:57.5% Here they are. 42:04.866 --> 42:06.200 align:left position:17.5%,start line:5% size:72.5% We found the same pattern. 42:06.300 --> 42:08.333 align:left position:22.5%,start line:5% size:67.5% We found that children in the spaced condition 42:08.433 --> 42:10.866 align:left position:17.5%,start line:5% size:72.5% significantly outperformed children in the clumped 42:10.966 --> 42:13.033 align:left position:22.5%,start line:5% size:67.5% and massed conditions. 42:13.133 --> 42:15.366 align:left position:35%,start line:5% size:55% So what these classroom-based studies do 42:15.466 --> 42:17.733 align:left position:25%,start line:5% size:65% is they help teachers to understand 42:17.833 --> 42:19.800 align:left position:35%,start line:5% size:55% how they can manipulate forgetting 42:19.900 --> 42:22.600 align:left position:20%,start line:5% size:70% by using spaced learning in their curriculum 42:22.700 --> 42:25.066 align:left position:10%,start line:5% size:80% and in their teaching practices. 42:25.166 --> 42:28.733 align:left position:10%,start line:71% size:80% And indeed, it's been a real joy for us to work one-on-one 42:28.833 --> 42:32.333 align:left position:17.5%,start line:71% size:72.5% with teachers in classrooms to help improve STEM learning 42:32.433 --> 42:34.933 align:left position:25%,start line:71% size:65% by just making these simple changes. 42:35.033 --> 42:37.766 align:left position:30%,start line:71% size:60% It's amazing how just small changes 42:37.866 --> 42:39.833 align:left position:15%,start line:71% size:75% in the timing of the lessons 42:39.933 --> 42:41.866 align:left position:20%,start line:71% size:70% can create more learning in the classroom. 42:41.966 --> 42:45.266 align:left position:25%,start line:71% size:65% And indeed, this is a free, innovative way 42:45.366 --> 42:46.500 align:left position:25%,start line:71% size:65% to improve education. 42:46.600 --> 42:49.466 align:left position:27.5%,start line:71% size:62.5% And we're actively studying how to develop 42:49.566 --> 42:51.200 align:left position:15%,start line:71% size:75% these types of interventions 42:51.300 --> 42:54.266 align:left position:20%,start line:71% size:70% so that we can encourage forgetting in the classroom 42:54.366 --> 42:56.666 align:left position:22.5%,start line:71% size:67.5% and encourage teachers to think about 42:56.766 --> 43:00.233 align:left position:22.5%,start line:71% size:67.5% how they can encourage forgetting in their students. 43:01.666 --> 43:04.633 align:left position:27.5%,start line:71% size:62.5% So this is just an active area of research 43:04.733 --> 43:08.033 align:left position:30%,start line:71% size:60% and is, you know, to be determined 43:08.133 --> 43:10.933 align:left position:35%,start line:71% size:55% how much more we can do with this. 43:11.033 --> 43:12.333 align:left position:25%,start line:71% size:65% You know, in another year or two, 43:12.433 --> 43:15.800 align:left position:25%,start line:71% size:65% please contact me and we'll have more information 43:15.900 --> 43:18.533 align:left position:20%,start line:71% size:70% about how the curriculum interventions are going. 43:19.600 --> 43:20.700 align:left position:17.5%,start line:71% size:72.5% Another concluding thought 43:20.800 --> 43:22.500 align:left position:25%,start line:71% size:65% that I really wanted to share with you today 43:22.600 --> 43:24.900 align:left position:27.5%,start line:71% size:62.5% is how researchers are actively studying 43:25.000 --> 43:27.066 align:left position:10%,start line:71% size:80% forgetting in the current times, 43:27.166 --> 43:30.300 align:left position:30%,start line:71% size:60% namely during the COVID-19 pandemic. 43:30.400 --> 43:32.700 align:left position:22.5%,start line:71% size:67.5% And if you're like me, you may have noticed, 43:32.800 --> 43:35.000 align:left position:27.5%,start line:71% size:62.5% particularly during the lockdown period, 43:35.100 --> 43:37.500 align:left position:27.5%,start line:71% size:62.5% that your thinking and learning have changed 43:37.600 --> 43:40.233 align:left position:27.5%,start line:71% size:62.5% during the pandemic and in particular, 43:40.333 --> 43:43.366 align:left position:25%,start line:71% size:65% that you've forgotten faster than you normally do. 43:43.466 --> 43:45.000 align:left position:15%,start line:71% size:75% So you might lose your keys. 43:45.100 --> 43:47.566 align:left position:27.5%,start line:71% size:62.5% You might not know what you had for lunch. 43:47.666 --> 43:50.366 align:left position:15%,start line:71% size:75% You're forgetting things that you normally wouldn't forget. 43:50.466 --> 43:53.000 align:left position:25%,start line:71% size:65% And there's a number of reasons of why 43:53.100 --> 43:55.566 align:left position:25%,start line:71% size:65% you were experiencing that faster forgetting. 43:55.666 --> 43:59.666 align:left position:12.5%,start line:71% size:77.5% Here's a quick summary of what research has found. 43:59.766 --> 44:04.466 align:left position:12.5%,start line:71% size:77.5%   So first, we know that there are routine changes. 44:04.566 --> 44:05.800 align:left position:30%,start line:83% size:60% You're not going into the office, 44:05.900 --> 44:07.566 align:left position:15%,start line:89% size:75% you're not going to the gym. 44:07.666 --> 44:10.366 align:left position:27.5%,start line:83% size:62.5% And the reason that that affects our memory 44:10.466 --> 44:14.366 align:left position:25%,start line:71% size:65% is that our routines serve as memory cues. 44:14.466 --> 44:16.500 align:left position:30%,start line:71% size:60% We learn where we always put our keys 44:16.600 --> 44:19.066 align:left position:20%,start line:71% size:70% when we go to the office, where we put our lunch, 44:19.166 --> 44:22.000 align:left position:22.5%,start line:71% size:67.5% who we talk to and have chit-chat with in the hallway. 44:22.100 --> 44:24.600 align:left position:12.5%,start line:71% size:77.5% And when we lose that routine, we lose the cues. 44:24.700 --> 44:28.566 align:left position:17.5%,start line:71% size:72.5% And so what that's doing is it's speeding up forgetting. 44:28.666 --> 44:30.866 align:left position:17.5%,start line:71% size:72.5% If we don't have the cues, we're not gonna remember, 44:30.966 --> 44:32.066 align:left position:32.5%,start line:71% size:57.5% and we're gonna continue to forget 44:32.166 --> 44:34.133 align:left position:12.5%,start line:71% size:77.5% according to that faster rate. 44:35.800 --> 44:38.600 align:left position:30%,start line:71% size:60% The second reason that we observe 44:38.700 --> 44:40.566 align:left position:30%,start line:71% size:60% faster forgetting during the pandemic 44:40.666 --> 44:44.900 align:left position:25%,start line:71% size:65% has to do with a lack of social interaction. 44:45.000 --> 44:47.533 align:left position:25%,start line:71% size:65%   Social interaction is important for so many reasons. 44:47.633 --> 44:49.500 align:left position:10%,start line:89% size:80% And I want to highlight two now. 44:50.500 --> 44:51.633 align:left position:22.5%,start line:71% size:67.5% So during the pandemic, 44:51.733 --> 44:54.366 align:left position:25%,start line:71% size:65% you haven't spent as much time with people 44:54.466 --> 44:57.100 align:left position:32.5%,start line:71% size:57.5% and people also serve as memory cues. 44:57.200 --> 44:59.233 align:left position:27.5%,start line:71% size:62.5% They prompt you to talk about your past. 44:59.333 --> 45:01.500 align:left position:17.5%,start line:71% size:72.5% So just imagine that you're chatting with a friend 45:01.600 --> 45:03.200 align:left position:27.5%,start line:71% size:62.5% or a family member, they might say, 45:03.300 --> 45:04.633 align:left position:15%,start line:71% size:75% "So what'd you do last week?" 45:04.733 --> 45:05.833 align:left position:22.5%,start line:71% size:67.5% And you responded with, 45:05.933 --> 45:09.033 align:left position:25%,start line:71% size:65% "Well, I got to talk to some friends. 45:09.133 --> 45:11.433 align:left position:27.5%,start line:71% size:62.5% I spent some time, it was so much fun." 45:11.533 --> 45:14.433 align:left position:25%,start line:71% size:65% And what you're doing by having that conversation 45:14.533 --> 45:16.933 align:left position:22.5%,start line:71% size:67.5% is you're recollecting your past experiences 45:17.033 --> 45:19.300 align:left position:17.5%,start line:71% size:72.5% and sharing them with that other person. 45:19.400 --> 45:22.533 align:left position:20%,start line:71% size:70% And so when people aren't around to prompt you, 45:22.633 --> 45:25.633 align:left position:17.5%,start line:71% size:72.5% you're not engaging as much practice in retrieving the past. 45:25.733 --> 45:28.500 align:left position:17.5%,start line:71% size:72.5% And again, that contributes to how fast you forget. 45:29.666 --> 45:32.433 align:left position:15%,start line:71% size:75% The other reason that social partners are so important 45:32.533 --> 45:35.533 align:left position:30%,start line:71% size:60% for our memory is that they contribute 45:35.633 --> 45:37.066 align:left position:15%,start line:71% size:75% to our emotional well-being. 45:37.166 --> 45:39.100 align:left position:12.5%,start line:71% size:77.5% And we know from a long history of research 45:39.200 --> 45:40.666 align:left position:22.5%,start line:71% size:67.5% on emotions and memory 45:40.766 --> 45:43.166 align:left position:27.5%,start line:71% size:62.5% is that when we're experiencing more volatile, 45:43.266 --> 45:45.200 align:left position:22.5%,start line:71% size:67.5% emotional experiences, 45:45.300 --> 45:47.033 align:left position:27.5%,start line:71% size:62.5% and when we're sort of experiencing 45:47.133 --> 45:48.666 align:left position:17.5%,start line:71% size:72.5% more negative life events, 45:48.766 --> 45:52.800 align:left position:12.5%,start line:71% size:77.5% that we actually forget faster during those times. 45:52.900 --> 45:55.033 align:left position:22.5%,start line:71% size:67.5% And so for those of you who are really missing 45:55.133 --> 45:59.166 align:left position:20%,start line:71% size:70% being with other people, and, you know, 45:59.266 --> 46:02.633 align:left position:22.5%,start line:71% size:67.5% are just sort of having a case of the blues, 46:02.733 --> 46:04.300 align:left position:12.5%,start line:71% size:77.5% you're forgetting faster may be 46:04.400 --> 46:06.633 align:left position:32.5%,start line:71% size:57.5% because of your current emotional state 46:06.733 --> 46:08.533 align:left position:22.5%,start line:71% size:67.5% or the emotional state that you experienced, 46:08.633 --> 46:10.533 align:left position:10%,start line:71% size:80% particularly during the lockdown 46:10.633 --> 46:15.033 align:left position:20%,start line:71% size:70% when you had little to no social interaction with people. 46:15.133 --> 46:18.333 align:left position:20%,start line:71% size:70% So there are many reasons that our social partners 46:18.433 --> 46:22.966 align:left position:17.5%,start line:71% size:72.5% are particularly important for our memory. 46:24.133 --> 46:28.233 align:left position:12.5%,start line:71% size:77.5% The third reason that we think people are forgetting faster 46:28.333 --> 46:32.533 align:left position:17.5%,start line:71% size:72.5% during the pandemic is that we're engaging in more behaviors 46:32.633 --> 46:35.200 align:left position:20%,start line:71% size:70% that speed up forgetting. 46:35.300 --> 46:38.800 align:left position:17.5%,start line:71% size:72.5% And one of those behaviors is alcohol consumption. 46:38.900 --> 46:40.833 align:left position:17.5%,start line:71% size:72.5%   So there's a lot of research showing 46:40.933 --> 46:42.366 align:left position:12.5%,start line:89% size:77.5% that during the last 18 months, 46:42.466 --> 46:44.633 align:left position:30%,start line:83% size:60% people have been drinking more alcohol 46:44.733 --> 46:46.333 align:left position:15%,start line:89% size:75% and engaging in more drug use 46:46.433 --> 46:49.233 align:left position:27.5%,start line:83% size:62.5% than they did prior to the pandemic. 46:49.333 --> 46:51.666 align:left position:20%,start line:71% size:70% And we know from research on alcohol and drugs 46:51.766 --> 46:56.033 align:left position:27.5%,start line:71% size:62.5% that they act as a memory destabilizer 46:56.133 --> 46:59.266 align:left position:27.5%,start line:71% size:62.5% and therefore cause faster forgetting. 46:59.366 --> 47:02.600 align:left position:25%,start line:71% size:65% So if you're engaging in an over-consumption 47:02.700 --> 47:07.033 align:left position:15%,start line:71% size:75% of these substances, that can lead to complete memory loss. 47:07.133 --> 47:08.700 align:left position:30%,start line:71% size:60% Not only are you forgetting faster, 47:08.800 --> 47:12.733 align:left position:22.5%,start line:71% size:67.5% but you might not have any access to memories 47:13.733 --> 47:16.900 align:left position:30%,start line:71% size:60% from those states of over consumption. 47:17.000 --> 47:19.800 align:left position:17.5%,start line:71% size:72.5% So certainly we think that a lot of the forgetting 47:19.900 --> 47:22.100 align:left position:30%,start line:71% size:60% that's happening because of the pandemic 47:22.200 --> 47:25.400 align:left position:12.5%,start line:71% size:77.5% is because people are choosing to engage in behaviors 47:25.500 --> 47:28.133 align:left position:15%,start line:71% size:75% that are negative, that they for memory at least, 47:28.233 --> 47:30.066 align:left position:20%,start line:71% size:70% that they didn't before. 47:31.766 --> 47:35.866 align:left position:15%,start line:83% size:75% The last reason is that many of us during the pandemic 47:35.966 --> 47:38.266 align:left position:22.5%,start line:89% size:67.5% had lifestyle changes. 47:38.366 --> 47:41.333 align:left position:32.5%,start line:83% size:57.5% And one of the big lifestyle changes 47:41.433 --> 47:43.766 align:left position:27.5%,start line:83% size:62.5% is that many of us exercised less. 47:43.866 --> 47:47.633 align:left position:15%,start line:71% size:75% And this is even despite the public service announcements 47:47.733 --> 47:49.966 align:left position:12.5%,start line:71% size:77.5% in the news encouraging people 47:50.066 --> 47:52.000 align:left position:30%,start line:71% size:60% to get out there and go on a walk, 47:52.100 --> 47:54.500 align:left position:25%,start line:71% size:65% be outside, exercise. 47:54.600 --> 47:57.900 align:left position:12.5%,start line:71% size:77.5% And one of the reasons for that public service announcement 47:58.000 --> 48:00.366 align:left position:20%,start line:71% size:70% or why it was in the news all the time 48:00.466 --> 48:03.100 align:left position:25%,start line:71% size:65% is that we know that exercise is so valuable 48:03.200 --> 48:04.333 align:left position:27.5%,start line:71% size:62.5% for so many things, 48:04.433 --> 48:06.166 align:left position:25%,start line:71% size:65% our physical health, our mental health, 48:06.266 --> 48:09.633 align:left position:25%,start line:71% size:65% and the rate at which we forget information. 48:09.733 --> 48:12.266 align:left position:22.5%,start line:71% size:67.5% We have a long sort of big body of work showing 48:12.366 --> 48:16.966 align:left position:12.5%,start line:71% size:77.5% that for those of us who engage in more cardiovascular exercise, 48:17.066 --> 48:19.633 align:left position:10%,start line:71% size:80% but exercise more generally too, 48:19.733 --> 48:24.000 align:left position:30%,start line:71% size:60% that we are more, we're more readily able 48:24.100 --> 48:27.333 align:left position:25%,start line:71% size:65% to retrieve important information when we need to. 48:27.433 --> 48:30.133 align:left position:27.5%,start line:71% size:62.5% So in other words, exercise is good 48:30.233 --> 48:34.533 align:left position:20%,start line:71% size:70% and supports our ability to retrieve information. 48:34.633 --> 48:38.333 align:left position:15%,start line:71% size:75% And so, because of that, we, 48:38.433 --> 48:41.866 align:left position:12.5%,start line:71% size:77.5% you know, are forgetting faster if we're exercising less. 48:41.966 --> 48:45.066 align:left position:17.5%,start line:71% size:72.5% So in brief, there's a lot of lifestyle changes 48:45.166 --> 48:47.966 align:left position:10%,start line:71% size:80% that we made that aren't for the benefit of our memories. 48:48.066 --> 48:49.933 align:left position:15%,start line:71% size:75% And that's yet another reason 48:50.033 --> 48:52.500 align:left position:32.5%,start line:71% size:57.5% why we might be forgetting faster. 48:52.600 --> 48:54.300 align:left position:27.5%,start line:71% size:62.5% And researchers are actively studying, 48:54.400 --> 48:56.066 align:left position:25%,start line:71% size:65% now that we're coming out of the pandemic, 48:56.166 --> 48:58.400 align:left position:12.5%,start line:71% size:77.5% how our forgetting is changing. 48:58.500 --> 49:02.100 align:left position:10%,start line:71% size:80% We expect that once we establish those new routines, 49:02.200 --> 49:03.533 align:left position:17.5%,start line:71% size:72.5% live a healthier lifestyle, 49:03.633 --> 49:05.566 align:left position:27.5%,start line:71% size:62.5% that our forgetting will slow and go back 49:05.666 --> 49:08.300 align:left position:12.5%,start line:71% size:77.5% to be what it was pre-pandemic. 49:08.400 --> 49:11.833 align:left position:15%,start line:71% size:75% But we're also concerned that a small group of individuals 49:11.933 --> 49:14.100 align:left position:15%,start line:71% size:75% might not make those changes, 49:14.200 --> 49:17.066 align:left position:15%,start line:71% size:75% might continue to experience negative effects of the pandemic 49:17.166 --> 49:18.766 align:left position:10%,start line:71% size:80% and thus have faster forgetting. 49:18.866 --> 49:21.400 align:left position:17.5%,start line:71% size:72.5% So researchers are actively trying to figure out 49:21.500 --> 49:23.866 align:left position:27.5%,start line:71% size:62.5% how we can identify those individuals 49:23.966 --> 49:25.700 align:left position:20%,start line:71% size:70% so that we can help them. 49:27.433 --> 49:29.833 align:left position:17.5%,start line:71% size:72.5% My final concluding thought is just to say 49:29.933 --> 49:32.833 align:left position:27.5%,start line:71% size:62.5% that we don't know why we forget, 49:32.933 --> 49:35.966 align:left position:27.5%,start line:71% size:62.5%   and we are actively studying it now, 49:36.066 --> 49:40.633 align:left position:12.5%,start line:83% size:77.5% but we do know that forgetting is essential for our lives. 49:41.766 --> 49:43.366 align:left position:22.5%,start line:83% size:67.5% Forgetting can help us to remember. 49:43.466 --> 49:45.133 align:left position:32.5%,start line:83% size:57.5% It can help us to learn new things, 49:45.233 --> 49:47.666 align:left position:15%,start line:89% size:75% like new words and concepts. 49:47.766 --> 49:51.333 align:left position:25%,start line:83% size:65% But most importantly, it can define who we are. 49:51.433 --> 49:53.866 align:left position:30%,start line:71% size:60% If we think back to the pandemic, 49:53.966 --> 49:55.033 align:left position:22.5%,start line:71% size:67.5% there's a lot of things 49:55.133 --> 49:57.666 align:left position:25%,start line:71% size:65% that we probably want to forget, right? 49:57.766 --> 49:59.633 align:left position:32.5%,start line:71% size:57.5% We had a lot of negative experiences, 49:59.733 --> 50:02.066 align:left position:27.5%,start line:71% size:62.5% particularly during the lockdown period, 50:02.166 --> 50:04.166 align:left position:15%,start line:71% size:75% and that forgetting is good. 50:04.266 --> 50:06.100 align:left position:22.5%,start line:71% size:67.5% So even though you may have forgotten faster 50:06.200 --> 50:08.133 align:left position:22.5%,start line:71% size:67.5% during the pandemic and forgotten a lot of the things 50:08.233 --> 50:09.366 align:left position:25%,start line:71% size:65% that happened to you, 50:09.466 --> 50:11.333 align:left position:27.5%,start line:71% size:62.5% I would argue that that's a good thing. 50:11.433 --> 50:13.133 align:left position:27.5%,start line:71% size:62.5% What your mind and brain are doing 50:13.233 --> 50:17.066 align:left position:17.5%,start line:71% size:72.5% is they're abstracting out what's important to remember, 50:17.166 --> 50:21.766 align:left position:20%,start line:71% size:70% hopefully the good things and the parts of yourself 50:21.866 --> 50:25.400 align:left position:20%,start line:71% size:70% that were able to endure during the pandemic. 50:25.500 --> 50:26.800 align:left position:12.5%,start line:71% size:77.5% And I'm hoping for all of you, 50:26.900 --> 50:28.833 align:left position:32.5%,start line:71% size:57.5% that you have a stronger sense of self 50:28.933 --> 50:33.366 align:left position:17.5%,start line:71% size:72.5% and know more about how you can endure in tough situations. 50:33.466 --> 50:35.466 align:left position:30%,start line:71% size:60% And forgetting is gonna help you do that. 50:35.566 --> 50:38.566 align:left position:22.5%,start line:71% size:67.5% It's gonna help you to remember when you were strong. 50:39.566 --> 50:43.300 align:left position:22.5%,start line:71% size:67.5% So on that note, I just want to say forgetting, 50:43.400 --> 50:45.600 align:left position:20%,start line:71% size:70% although intuitively may seem like a bad thing, 50:45.700 --> 50:46.866 align:left position:30%,start line:71% size:60% is a great thing, 50:46.966 --> 50:49.566 align:left position:15%,start line:71% size:75% and it's helping you with all facets of your life. 50:50.566 --> 50:52.466 align:left position:10%,start line:5% size:80% Thank you so much for listening. 50:52.566 --> 50:53.666 align:left position:15%,start line:5% size:75% Please feel free to reach out 50:53.766 --> 50:55.000 align:left position:25%,start line:5% size:65% if you have questions about forgetting. 50:55.100 --> 50:57.366 align:left position:25%,start line:5% size:65% As I mentioned at the beginning of the talk, 50:57.466 --> 50:59.400 align:left position:25%,start line:5% size:65% I spend lots of time thinking and learning 50:59.500 --> 51:00.566 align:left position:15%,start line:5% size:75% about thinking and learning, 51:00.666 --> 51:02.966 align:left position:17.5%,start line:5% size:72.5% and I would love to do that with you as well. 51:03.066 --> 51:04.233 align:left position:35%,start line:5% size:55% Good evening.