WEBVTT 00:00:00.000 --> 00:00:02.520 align:middle line:84% The following content is provided under a Creative 00:00:02.520 --> 00:00:04.030 align:middle line:90% Commons license. 00:00:04.030 --> 00:00:06.370 align:middle line:84% Your support will help MIT OpenCourseWare 00:00:06.370 --> 00:00:10.740 align:middle line:84% continue to offer high quality educational resources for free. 00:00:10.740 --> 00:00:13.350 align:middle line:84% To make a donation or view additional materials 00:00:13.350 --> 00:00:17.237 align:middle line:84% from hundreds of MIT courses, visit MIT OpenCourseWare 00:00:17.237 --> 00:00:17.862 align:middle line:90% at ocw.mit.edu. 00:00:17.862 --> 00:00:23.230 align:middle line:90% 00:00:23.230 --> 00:00:26.360 align:middle line:84% PROFESSOR: All right, a little less time today, 00:00:26.360 --> 00:00:28.900 align:middle line:84% because I gave you a little extra time on that 00:00:28.900 --> 00:00:33.030 align:middle line:84% since you were obviously needing a little more time. 00:00:33.030 --> 00:00:40.160 align:middle line:90% 00:00:40.160 --> 00:00:44.190 align:middle line:84% For this class and Friday's class, 00:00:44.190 --> 00:00:49.470 align:middle line:84% after a little bit on early evolution and behavior, 00:00:49.470 --> 00:00:53.750 align:middle line:84% we'll say a little bit about genetics and learning. 00:00:53.750 --> 00:00:59.860 align:middle line:84% Then mostly Friday we'll get to the topic of navigation 00:00:59.860 --> 00:01:03.830 align:middle line:84% and migration, how animals find their way 00:01:03.830 --> 00:01:13.600 align:middle line:84% on foraging trips and other behavior that involves movement 00:01:13.600 --> 00:01:14.945 align:middle line:90% quite a ways from their homes. 00:01:14.945 --> 00:01:22.860 align:middle line:90% 00:01:22.860 --> 00:01:25.350 align:middle line:84% There's not much in the readings on these topics, 00:01:25.350 --> 00:01:32.000 align:middle line:84% but they come up in studies of the brain 00:01:32.000 --> 00:01:35.370 align:middle line:84% and certainly belong in a behavior class. 00:01:35.370 --> 00:01:39.020 align:middle line:84% I want to know the most basic multipurpose movement 00:01:39.020 --> 00:01:40.930 align:middle line:90% abilities of animals. 00:01:40.930 --> 00:01:46.775 align:middle line:84% We talked about multipurpose movement abilities already, 00:01:46.775 --> 00:01:49.850 align:middle line:84% but I want to know what are the multipurpose movement 00:01:49.850 --> 00:01:52.950 align:middle line:84% abilities that you find even in single-celled organisms. 00:01:52.950 --> 00:01:55.880 align:middle line:84% In fact, you find them all the way from protozoa to primates. 00:01:55.880 --> 00:01:58.980 align:middle line:90% 00:01:58.980 --> 00:02:02.550 align:middle line:84% They're the ones we're familiar with besides elementary life 00:02:02.550 --> 00:02:12.494 align:middle line:84% support behaviors and movements within the cell, we have these. 00:02:12.494 --> 00:02:16.420 align:middle line:84% Even In protozoa you have locomotor activity 00:02:16.420 --> 00:02:18.610 align:middle line:84% for approach and avoidance, foraging, 00:02:18.610 --> 00:02:25.375 align:middle line:84% feeding, and for escape from predators. 00:02:25.375 --> 00:02:29.630 align:middle line:84% You have orienting movements in response to sensory inputs, 00:02:29.630 --> 00:02:33.730 align:middle line:84% and you have various kinds of grasping. 00:02:33.730 --> 00:02:36.850 align:middle line:84% Grasping doesn't always mean manual grasping. 00:02:36.850 --> 00:02:40.020 align:middle line:84% It can be oral grasping, and so forth, 00:02:40.020 --> 00:02:42.340 align:middle line:90% and other kinds of grasping. 00:02:42.340 --> 00:02:46.860 align:middle line:84% If you're a snake, obviously it's either oral, 00:02:46.860 --> 00:02:51.010 align:middle line:84% or they have another means of grasping. 00:02:51.010 --> 00:02:54.750 align:middle line:84% Then you have various special purpose movements. 00:02:54.750 --> 00:02:57.965 align:middle line:84% These vary a lot more between species. 00:02:57.965 --> 00:03:00.780 align:middle line:90% 00:03:00.780 --> 00:03:06.020 align:middle line:84% Is that any different now for multicellular animals? 00:03:06.020 --> 00:03:10.470 align:middle line:84% Actually all those behaviors listed 00:03:10.470 --> 00:03:13.620 align:middle line:84% for the single-celled organisms apply to multicellular 00:03:13.620 --> 00:03:16.660 align:middle line:90% animals of all sorts. 00:03:16.660 --> 00:03:21.040 align:middle line:84% I just want to point out that invertebrates, 00:03:21.040 --> 00:03:27.020 align:middle line:84% even if you just eliminate the entire forebrain, 00:03:27.020 --> 00:03:32.024 align:middle line:84% you find these basic movement abilities represented. 00:03:32.024 --> 00:03:34.910 align:middle line:84% They're represented in the midbrain. 00:03:34.910 --> 00:03:39.380 align:middle line:84% They're basic to the organization of the midbrain-- 00:03:39.380 --> 00:03:44.100 align:middle line:84% control of locomotion, control of orienting movements, 00:03:44.100 --> 00:03:47.510 align:middle line:84% and control of various kinds of grasping movements. 00:03:47.510 --> 00:03:51.480 align:middle line:90% 00:03:51.480 --> 00:03:56.470 align:middle line:84% But what we've been calling the action-specific potential-- 00:03:56.470 --> 00:04:00.170 align:middle line:84% that is the motivation behind these movements, 00:04:00.170 --> 00:04:03.230 align:middle line:84% the motivations that usually lead 00:04:03.230 --> 00:04:06.000 align:middle line:84% to these various multipurpose movements-- 00:04:06.000 --> 00:04:12.090 align:middle line:90% 00:04:12.090 --> 00:04:16.920 align:middle line:84% then the forebrain is much more involved. 00:04:16.920 --> 00:04:21.800 align:middle line:84% I want to try to summarize basic support systems in very 00:04:21.800 --> 00:04:25.320 align:middle line:84% general terms, and then we'll talk about the regulators 00:04:25.320 --> 00:04:27.070 align:middle line:84% and controllers of behavior, which 00:04:27.070 --> 00:04:29.710 align:middle line:84% are really the motivational states of the forebrain. 00:04:29.710 --> 00:04:33.720 align:middle line:90% 00:04:33.720 --> 00:04:38.170 align:middle line:84% I like the way the neuroanatomists here at MIT 00:04:38.170 --> 00:04:43.440 align:middle line:84% for many years while [INAUDIBLE] describe the basic supports 00:04:43.440 --> 00:04:46.800 align:middle line:84% underlying all behavior as stabilities-- 00:04:46.800 --> 00:04:49.150 align:middle line:90% three types of stabilities. 00:04:49.150 --> 00:04:50.480 align:middle line:90% What do we keep stable? 00:04:50.480 --> 00:04:53.250 align:middle line:90% 00:04:53.250 --> 00:04:58.670 align:middle line:84% We're talking about internal automatisms and reflexes, what 00:04:58.670 --> 00:05:01.300 align:middle line:90% we call the mantle of reflexes. 00:05:01.300 --> 00:05:05.170 align:middle line:84% First of all, stability of the internal environment, 00:05:05.170 --> 00:05:09.070 align:middle line:84% the vital functions, respiration, breathing-- now 00:05:09.070 --> 00:05:10.940 align:middle line:90% does that involve behavior? 00:05:10.940 --> 00:05:13.600 align:middle line:84% Well certainly, very simple breathing behavior, of course, 00:05:13.600 --> 00:05:16.540 align:middle line:84% but if we have trouble breathing, 00:05:16.540 --> 00:05:18.110 align:middle line:84% we'll see other kinds of behavior 00:05:18.110 --> 00:05:26.060 align:middle line:84% to try to get enough oxygen. You have circulation of the blood. 00:05:26.060 --> 00:05:28.430 align:middle line:84% That's regulated by reflex actions. 00:05:28.430 --> 00:05:31.940 align:middle line:90% 00:05:31.940 --> 00:05:34.260 align:middle line:84% Regulation of the chemical environment-- 00:05:34.260 --> 00:05:39.470 align:middle line:84% the blood, the lymphatic fluids, the various extracellular 00:05:39.470 --> 00:05:41.080 align:middle line:90% fluids-- 00:05:41.080 --> 00:05:43.950 align:middle line:90% that involves reflexes. 00:05:43.950 --> 00:05:50.110 align:middle line:84% Feedback control systems-- homeostatic mechanisms, 00:05:50.110 --> 00:05:52.120 align:middle line:90% generally. 00:05:52.120 --> 00:05:57.800 align:middle line:84% Then of course, we regulate temperature, 00:05:57.800 --> 00:06:01.450 align:middle line:84% and that involves reflex actions and involves fixed action 00:06:01.450 --> 00:06:04.640 align:middle line:90% patterns of various sorts. 00:06:04.640 --> 00:06:09.750 align:middle line:84% These vary somewhat across species, 00:06:09.750 --> 00:06:15.480 align:middle line:84% but there's some similarity in all the vertebrates. 00:06:15.480 --> 00:06:17.620 align:middle line:84% That's stability of the internal environment. 00:06:17.620 --> 00:06:20.980 align:middle line:84% Then we have stability in space, and this 00:06:20.980 --> 00:06:24.920 align:middle line:90% includes postural support-- 00:06:24.920 --> 00:06:29.820 align:middle line:84% various reflex actions that we've talked about. 00:06:29.820 --> 00:06:33.140 align:middle line:84% It includes maintaining balance and direction 00:06:33.140 --> 00:06:35.615 align:middle line:90% during locomotion, as well. 00:06:35.615 --> 00:06:38.060 align:middle line:84% That all can be called stability in space. 00:06:38.060 --> 00:06:40.080 align:middle line:84% Some people would say it also includes 00:06:40.080 --> 00:06:42.660 align:middle line:84% other kinds of spatially-oriented behavior, 00:06:42.660 --> 00:06:45.890 align:middle line:84% including the orienting behaviors. 00:06:45.890 --> 00:06:49.890 align:middle line:90% Finally, stability in time-- 00:06:49.890 --> 00:06:55.560 align:middle line:84% if I just am talking about the level of automatisms, including 00:06:55.560 --> 00:06:57.650 align:middle line:84% reflexes and feedback mechanisms, 00:06:57.650 --> 00:06:59.470 align:middle line:90% then we're talking about-- 00:06:59.470 --> 00:07:01.970 align:middle line:84% we have to include, though, the temporal organization 00:07:01.970 --> 00:07:04.760 align:middle line:84% of the day-night cycle, the circadian 00:07:04.760 --> 00:07:10.485 align:middle line:84% rhythms, and their entrainment by the light-dark cycle, 00:07:10.485 --> 00:07:13.560 align:middle line:90% the cycle of the sun. 00:07:13.560 --> 00:07:15.880 align:middle line:84% We have longer and shorter rhythms, as well, 00:07:15.880 --> 00:07:20.250 align:middle line:84% but the major thing is motivational persistence. 00:07:20.250 --> 00:07:24.850 align:middle line:84% Without our motivational states, animals in general 00:07:24.850 --> 00:07:29.280 align:middle line:84% would flit from one thing to the other, 00:07:29.280 --> 00:07:31.870 align:middle line:84% depending on what, at the moment, was dominant. 00:07:31.870 --> 00:07:36.040 align:middle line:84% But motivation tends to persist, and that gives some unity 00:07:36.040 --> 00:07:39.340 align:middle line:90% to current behavior. 00:07:39.340 --> 00:07:41.610 align:middle line:84% That's all part of stability in time, 00:07:41.610 --> 00:07:45.463 align:middle line:84% and it's all regulated pretty automatically. 00:07:45.463 --> 00:07:48.490 align:middle line:90% 00:07:48.490 --> 00:07:52.240 align:middle line:84% Of course, stability in time can be extended a lot when you 00:07:52.240 --> 00:07:53.950 align:middle line:90% deal with forebrain mechanisms. 00:07:53.950 --> 00:07:57.270 align:middle line:90% 00:07:57.270 --> 00:07:59.100 align:middle line:84% I'm asking here for which of the three 00:07:59.100 --> 00:08:00.910 align:middle line:90% is the forebrain most important. 00:08:00.910 --> 00:08:02.880 align:middle line:84% I've already answered it, really-- 00:08:02.880 --> 00:08:04.530 align:middle line:90% it's stability in time. 00:08:04.530 --> 00:08:12.210 align:middle line:90% 00:08:12.210 --> 00:08:15.840 align:middle line:84% Above these basic support systems 00:08:15.840 --> 00:08:20.030 align:middle line:84% are the regulators of behavior, the basic controllers we call 00:08:20.030 --> 00:08:21.765 align:middle line:90% drives, motivational systems. 00:08:21.765 --> 00:08:25.800 align:middle line:90% 00:08:25.800 --> 00:08:27.630 align:middle line:90% And I want to just list them. 00:08:27.630 --> 00:08:30.005 align:middle line:84% Now you actually did this somewhat 00:08:30.005 --> 00:08:33.380 align:middle line:90% when you talked about ethograms. 00:08:33.380 --> 00:08:37.640 align:middle line:90% It's really a similar thing. 00:08:37.640 --> 00:08:45.020 align:middle line:84% If we just talk about the various kinds of what 00:08:45.020 --> 00:08:48.380 align:middle line:84% behavioral neuroscientists would call the controllers, 00:08:48.380 --> 00:08:51.090 align:middle line:90% or regulators of behavior. 00:08:51.090 --> 00:08:55.850 align:middle line:84% We, for example, can start with ingestion, drives, 00:08:55.850 --> 00:09:02.350 align:middle line:84% or motivations, various related drives-- foraging, predation. 00:09:02.350 --> 00:09:05.610 align:middle line:84% Then a couple kinds of defensive behavior-- 00:09:05.610 --> 00:09:09.820 align:middle line:84% anti-predator motivation, first of all, and then second, 00:09:09.820 --> 00:09:12.870 align:middle line:90% social, defensive behaviors-- 00:09:12.870 --> 00:09:15.020 align:middle line:90% part of social behavior. 00:09:15.020 --> 00:09:19.610 align:middle line:84% Then the various drives involved in reproduction-- 00:09:19.610 --> 00:09:23.140 align:middle line:84% I'm not saying each of these is a single drive, 00:09:23.140 --> 00:09:25.250 align:middle line:90% but we can group them. 00:09:25.250 --> 00:09:27.380 align:middle line:84% Then we have one that's often left out 00:09:27.380 --> 00:09:29.730 align:middle line:84% by ethologists, but not by Lorenz-- 00:09:29.730 --> 00:09:33.060 align:middle line:84% and it shouldn't be-- exploration of novelty. 00:09:33.060 --> 00:09:35.190 align:middle line:84% Novelty serves various roles, which 00:09:35.190 --> 00:09:37.100 align:middle line:90% we'll talk about in a minute. 00:09:37.100 --> 00:09:41.470 align:middle line:84% Then various other motivations, including motivations 00:09:41.470 --> 00:09:45.430 align:middle line:84% for elimination, for shelter and nest construction, 00:09:45.430 --> 00:09:49.490 align:middle line:84% for sleeping, for play, various social motivations, 00:09:49.490 --> 00:09:54.190 align:middle line:84% and we have to add to all these innate behaviors, 00:09:54.190 --> 00:09:56.310 align:middle line:90% the learned motivations. 00:09:56.310 --> 00:09:58.800 align:middle line:84% Because with learning, we also can 00:09:58.800 --> 00:10:02.730 align:middle line:84% acquire motivations associated with learned behavior-- 00:10:02.730 --> 00:10:05.850 align:middle line:90% 00:10:05.850 --> 00:10:08.480 align:middle line:84% something which is not as well understood, 00:10:08.480 --> 00:10:14.100 align:middle line:84% but it's clearly something we have to deal with. 00:10:14.100 --> 00:10:16.600 align:middle line:84% Just adding a little detail, ingestion drives 00:10:16.600 --> 00:10:18.650 align:middle line:84% would include both hunger and thirst-- 00:10:18.650 --> 00:10:19.640 align:middle line:90% the basic ones. 00:10:19.640 --> 00:10:23.440 align:middle line:90% 00:10:23.440 --> 00:10:26.310 align:middle line:84% And of course, you can get abnormal drives, too, 00:10:26.310 --> 00:10:32.340 align:middle line:84% but those are abnormalities acquired because of the reward 00:10:32.340 --> 00:10:36.700 align:middle line:84% involved and because of the availability 00:10:36.700 --> 00:10:43.120 align:middle line:90% of artificial things like drugs. 00:10:43.120 --> 00:10:46.720 align:middle line:84% But in fact, animals can also become abnormal 00:10:46.720 --> 00:10:48.890 align:middle line:90% in their hunger and thirst. 00:10:48.890 --> 00:10:51.780 align:middle line:84% That's why we talk about such things as food addiction, 00:10:51.780 --> 00:10:54.730 align:middle line:90% for example. 00:10:54.730 --> 00:10:58.030 align:middle line:84% Then the other drives related to feeding 00:10:58.030 --> 00:11:04.060 align:middle line:84% are foraging, predatory attack, and various predators. 00:11:04.060 --> 00:11:07.060 align:middle line:84% Prying in starlings is a separate drive. 00:11:07.060 --> 00:11:09.900 align:middle line:90% 00:11:09.900 --> 00:11:12.960 align:middle line:84% Poking with a spine is separate in cactus finches, 00:11:12.960 --> 00:11:13.630 align:middle line:90% and so forth. 00:11:13.630 --> 00:11:16.580 align:middle line:90% 00:11:16.580 --> 00:11:19.890 align:middle line:84% Then for defensive behavior, the various anti-predator 00:11:19.890 --> 00:11:22.840 align:middle line:84% behaviors, we have both escape and avoidance, 00:11:22.840 --> 00:11:24.090 align:middle line:90% two somewhat separate. 00:11:24.090 --> 00:11:29.120 align:middle line:84% We're going to deal with that separately later on, 00:11:29.120 --> 00:11:35.860 align:middle line:84% and we'll see a video about escape behavior. 00:11:35.860 --> 00:11:39.330 align:middle line:84% Then the various types of defense 00:11:39.330 --> 00:11:48.310 align:middle line:84% at the level of social behavior include territorial behavior, 00:11:48.310 --> 00:11:50.730 align:middle line:84% maintenance of a position in a hierarchy, 00:11:50.730 --> 00:11:53.600 align:middle line:84% achieving a position, maintaining it, improving it, 00:11:53.600 --> 00:11:54.610 align:middle line:90% and so forth. 00:11:54.610 --> 00:11:59.190 align:middle line:84% These all involve specific social motivations. 00:11:59.190 --> 00:12:02.130 align:middle line:84% And then various reproductive drives-- 00:12:02.130 --> 00:12:06.310 align:middle line:84% just some essential ones here-- pairing, involving, 00:12:06.310 --> 00:12:11.105 align:middle line:84% roaming or searching, advertising, selecting 00:12:11.105 --> 00:12:17.300 align:middle line:84% or responding, which we usually called mate selection. 00:12:17.300 --> 00:12:20.190 align:middle line:84% Then mating itself, brood-tending-- 00:12:20.190 --> 00:12:24.040 align:middle line:84% various aspects of parental behavior. 00:12:24.040 --> 00:12:26.760 align:middle line:84% Exploration of novelty-- just point out 00:12:26.760 --> 00:12:29.520 align:middle line:90% some of the roles of that. 00:12:29.520 --> 00:12:32.155 align:middle line:84% It plays a role in security and defense. 00:12:32.155 --> 00:12:37.820 align:middle line:90% 00:12:37.820 --> 00:12:41.310 align:middle line:84% When we see something novel, an animal 00:12:41.310 --> 00:12:43.530 align:middle line:84% will interrupt his current behavior. 00:12:43.530 --> 00:12:47.540 align:middle line:84% If he didn't do that, he often would be caught. 00:12:47.540 --> 00:12:50.300 align:middle line:84% He improves his ability to detect 00:12:50.300 --> 00:12:52.690 align:middle line:84% the source of the predator and the nature of the predator 00:12:52.690 --> 00:12:53.950 align:middle line:90% by his orienting movements. 00:12:53.950 --> 00:12:57.980 align:middle line:90% 00:12:57.980 --> 00:13:01.580 align:middle line:84% Of course animals, even if there's no predator turnaround, 00:13:01.580 --> 00:13:07.260 align:middle line:84% will explore novelty and expand what we call their cognitive 00:13:07.260 --> 00:13:09.250 align:middle line:84% map--- their map of the environment, 00:13:09.250 --> 00:13:10.750 align:middle line:84% their knowledge of the environment-- 00:13:10.750 --> 00:13:12.530 align:middle line:84% which is crucial for their ability 00:13:12.530 --> 00:13:15.560 align:middle line:90% to escape from predators. 00:13:15.560 --> 00:13:20.290 align:middle line:84% They're not escaping into an unknown area, 00:13:20.290 --> 00:13:23.170 align:middle line:84% but areas they know well, and they know the routes 00:13:23.170 --> 00:13:28.120 align:middle line:84% for getting back home or to getting to a hiding place. 00:13:28.120 --> 00:13:30.630 align:middle line:90% It plays a role in ingestion. 00:13:30.630 --> 00:13:34.380 align:middle line:84% We talk about neophobia and neophilia. 00:13:34.380 --> 00:13:40.040 align:middle line:84% If animals are starving, they tend to be more neophilic-- 00:13:40.040 --> 00:13:45.190 align:middle line:84% that is, they will seek novel foods, 00:13:45.190 --> 00:13:49.180 align:middle line:84% whereas normally if food is relatively plentiful, 00:13:49.180 --> 00:13:50.965 align:middle line:90% they will be neophobic. 00:13:50.965 --> 00:13:52.700 align:middle line:90% They will avoid novelty. 00:13:52.700 --> 00:13:56.240 align:middle line:90% 00:13:56.240 --> 00:13:58.660 align:middle line:84% And it does play a role in sexuality, 00:13:58.660 --> 00:14:02.400 align:middle line:84% as well, more in some species than others. 00:14:02.400 --> 00:14:05.350 align:middle line:84% There's many other motivations that we've 00:14:05.350 --> 00:14:06.710 align:middle line:90% mentioned, some of them before. 00:14:06.710 --> 00:14:11.290 align:middle line:90% 00:14:11.290 --> 00:14:14.230 align:middle line:84% This is another topic about genes and behavior, 00:14:14.230 --> 00:14:15.920 align:middle line:84% and I point out here at the beginning, 00:14:15.920 --> 00:14:20.040 align:middle line:84% that variations in a single gene can result 00:14:20.040 --> 00:14:21.780 align:middle line:90% in variations in behavior. 00:14:21.780 --> 00:14:25.540 align:middle line:84% I just want to know what kind of effects on the body 00:14:25.540 --> 00:14:28.340 align:middle line:90% does such a gene have to have. 00:14:28.340 --> 00:14:31.580 align:middle line:90% Well it's a very simple answer. 00:14:31.580 --> 00:14:37.710 align:middle line:84% If a gene has a specific effect on behavior, 00:14:37.710 --> 00:14:40.161 align:middle line:90% like it can be a gene-- 00:14:40.161 --> 00:14:43.380 align:middle line:84% if the animal has it, like a bee, 00:14:43.380 --> 00:14:47.000 align:middle line:84% he engages in cleaning out of the hive, 00:14:47.000 --> 00:14:50.460 align:middle line:84% and if he doesn't have it, he doesn't. 00:14:50.460 --> 00:14:52.690 align:middle line:84% You have these two kinds of bees-- the hygienic bees 00:14:52.690 --> 00:14:55.290 align:middle line:90% and the non-hygienic bees. 00:14:55.290 --> 00:14:56.495 align:middle line:90% What has to be different? 00:14:56.495 --> 00:15:01.420 align:middle line:90% 00:15:01.420 --> 00:15:04.890 align:middle line:84% What does the gene have to cause? 00:15:04.890 --> 00:15:11.030 align:middle line:84% The gene, by itself, knows, in single cells, 00:15:11.030 --> 00:15:13.553 align:middle line:84% the single cells aren't controlling behavior. 00:15:13.553 --> 00:15:17.530 align:middle line:90% 00:15:17.530 --> 00:15:20.026 align:middle line:90% So why is behavior different? 00:15:20.026 --> 00:15:23.410 align:middle line:84% How can the gene result in differences in behavior? 00:15:23.410 --> 00:15:25.500 align:middle line:84% Very simple-- must be differences 00:15:25.500 --> 00:15:31.470 align:middle line:84% in the nervous system, right, because that's 00:15:31.470 --> 00:15:36.650 align:middle line:84% the way we inherit fixed action patterns. 00:15:36.650 --> 00:15:40.260 align:middle line:84% Fixed action patterns depend on brain 00:15:40.260 --> 00:15:44.020 align:middle line:84% circuitry and other aspects of the brain, 00:15:44.020 --> 00:15:47.190 align:middle line:84% including hormones, for example, the chemical environment, 00:15:47.190 --> 00:15:50.720 align:middle line:90% and so forth. 00:15:50.720 --> 00:15:53.770 align:middle line:84% That's the kind of an effect it has to have. 00:15:53.770 --> 00:15:56.330 align:middle line:84% Generally, at least in invertebrates, the effect 00:15:56.330 --> 00:15:57.840 align:middle line:84% is on the central nervous system. 00:15:57.840 --> 00:16:02.800 align:middle line:90% 00:16:02.800 --> 00:16:05.235 align:middle line:84% And I point out, besides hormones here, it 00:16:05.235 --> 00:16:07.165 align:middle line:84% could be differences in sensory input 00:16:07.165 --> 00:16:10.820 align:middle line:84% and so forth that could result in changes in behavior-- 00:16:10.820 --> 00:16:13.510 align:middle line:90% 00:16:13.510 --> 00:16:17.330 align:middle line:84% that is if an animal inherited much higher sensory acuity 00:16:17.330 --> 00:16:19.400 align:middle line:84% or much lower thresholds to respond 00:16:19.400 --> 00:16:23.150 align:middle line:84% to certain types of inputs in the environment, 00:16:23.150 --> 00:16:24.750 align:middle line:90% it will change its behavior. 00:16:24.750 --> 00:16:27.800 align:middle line:90% 00:16:27.800 --> 00:16:30.250 align:middle line:84% Going back to the bees, here, the hygienic 00:16:30.250 --> 00:16:33.100 align:middle line:90% bees-- what are they? 00:16:33.100 --> 00:16:38.480 align:middle line:84% Why does a bee colony need hygienic bees? 00:16:38.480 --> 00:16:39.800 align:middle line:90% What do those bees do? 00:16:39.800 --> 00:16:43.715 align:middle line:84% It's described in Scott quite clearly. 00:16:43.715 --> 00:16:48.640 align:middle line:90% 00:16:48.640 --> 00:16:53.940 align:middle line:84% These are the bees that are opening up the cells, 00:16:53.940 --> 00:16:58.720 align:middle line:84% pulling out dead or dying larvae, getting rid 00:16:58.720 --> 00:17:02.200 align:middle line:90% of them, dumping them out. 00:17:02.200 --> 00:17:04.115 align:middle line:90% But not all bees do that. 00:17:04.115 --> 00:17:08.980 align:middle line:90% 00:17:08.980 --> 00:17:13.040 align:middle line:84% At least if you observe, say, a colony 00:17:13.040 --> 00:17:15.810 align:middle line:84% of many hundreds of bees, you'll see 00:17:15.810 --> 00:17:21.069 align:middle line:84% only a certain percentage of them will actually do that. 00:17:21.069 --> 00:17:22.280 align:middle line:90% The others just don't. 00:17:22.280 --> 00:17:25.770 align:middle line:90% 00:17:25.770 --> 00:17:30.310 align:middle line:84% Scott uses this as an example of genes in behavior, 00:17:30.310 --> 00:17:33.270 align:middle line:84% and he discusses it in terms of two genes. 00:17:33.270 --> 00:17:39.060 align:middle line:90% 00:17:39.060 --> 00:17:48.490 align:middle line:84% It's all based on one study that showed that you can create 00:17:48.490 --> 00:17:55.280 align:middle line:84% a colony where there's no hygienic bees, 00:17:55.280 --> 00:17:59.370 align:middle line:84% and you can have colonies with many more hygienic bees. 00:17:59.370 --> 00:18:03.370 align:middle line:84% The evidence is, from the paper he was studying, 00:18:03.370 --> 00:18:05.700 align:middle line:90% that it's based on two genes. 00:18:05.700 --> 00:18:12.740 align:middle line:84% Both tend to be dominant, and if they 00:18:12.740 --> 00:18:18.700 align:middle line:84% possess the non-dominant allele, then they will be hygienic. 00:18:18.700 --> 00:18:20.690 align:middle line:90% But why are there two genes? 00:18:20.690 --> 00:18:25.000 align:middle line:84% Because there's two behaviors involved, and they apparently, 00:18:25.000 --> 00:18:29.920 align:middle line:84% according to this study, they inherit separately the ability 00:18:29.920 --> 00:18:33.460 align:middle line:90% to do one or the other. 00:18:33.460 --> 00:18:36.490 align:middle line:84% In order to find dead larvae or dying larvae, 00:18:36.490 --> 00:18:40.520 align:middle line:84% they have to be able to open the cell in the hive-- 00:18:40.520 --> 00:18:41.960 align:middle line:90% so he calls that uncapping-- 00:18:41.960 --> 00:18:44.610 align:middle line:90% 00:18:44.610 --> 00:18:48.600 align:middle line:84% and the other involves actually getting into the cell 00:18:48.600 --> 00:18:50.350 align:middle line:90% and pulling out the dead larvae. 00:18:50.350 --> 00:18:52.220 align:middle line:84% That's another kind of behavior-- 00:18:52.220 --> 00:18:54.990 align:middle line:90% so two distinct behaviors. 00:18:54.990 --> 00:18:57.000 align:middle line:84% And the genetic studies indicate that you 00:18:57.000 --> 00:19:02.170 align:middle line:84% can have bees that will uncap, but won't clean out. 00:19:02.170 --> 00:19:04.470 align:middle line:84% And you can have other bees that won't uncap, 00:19:04.470 --> 00:19:07.890 align:middle line:84% but they will clean out dead larvae. 00:19:07.890 --> 00:19:11.320 align:middle line:84% That's why they concluded there have to be two separate genes. 00:19:11.320 --> 00:19:14.180 align:middle line:90% 00:19:14.180 --> 00:19:23.980 align:middle line:84% Then he goes on, and he points out that in a colony, 00:19:23.980 --> 00:19:25.700 align:middle line:84% you can have a colony, let's say, 00:19:25.700 --> 00:19:30.970 align:middle line:84% that contains all hygienic bees, but they don't all 00:19:30.970 --> 00:19:33.720 align:middle line:90% engage in hygienic behavior. 00:19:33.720 --> 00:19:38.980 align:middle line:84% You can have a colony that involves half hygienic bees, 00:19:38.980 --> 00:19:44.900 align:middle line:84% but 50% of them don't engage in hygienic behavior. 00:19:44.900 --> 00:19:48.580 align:middle line:84% Furthermore, they engage in the behavior only when they reach 00:19:48.580 --> 00:19:51.960 align:middle line:84% a certain age, and the age at which they 00:19:51.960 --> 00:19:54.330 align:middle line:84% start their hygienic behavior will actually 00:19:54.330 --> 00:19:58.275 align:middle line:84% depend on the proportion of hygienic bees in the colony. 00:19:58.275 --> 00:20:00.940 align:middle line:90% 00:20:00.940 --> 00:20:04.720 align:middle line:84% If there's many more, they will engage at an older age. 00:20:04.720 --> 00:20:08.090 align:middle line:84% If there's very few, then they will start younger. 00:20:08.090 --> 00:20:10.890 align:middle line:90% 00:20:10.890 --> 00:20:15.490 align:middle line:84% He spells out the numbers for that. 00:20:15.490 --> 00:20:20.130 align:middle line:84% I went to one of the studies he was using. 00:20:20.130 --> 00:20:22.370 align:middle line:84% The title I listed for you, there-- 00:20:22.370 --> 00:20:25.010 align:middle line:84% "Influence of Colony Genotype Composition 00:20:25.010 --> 00:20:27.930 align:middle line:84% on the Performance of Hygienic Behavior in the Honey Bee." 00:20:27.930 --> 00:20:30.980 align:middle line:90% 00:20:30.980 --> 00:20:37.210 align:middle line:84% They describe the creation of four colonies that 00:20:37.210 --> 00:20:43.140 align:middle line:84% had 25% hygienic bees, 100% hygienic bees, 00:20:43.140 --> 00:20:47.750 align:middle line:90% or 0% hygienic bees. 00:20:47.750 --> 00:20:50.680 align:middle line:84% This is from their table, where they're summarizing 00:20:50.680 --> 00:20:52.380 align:middle line:90% many of the results. 00:20:52.380 --> 00:20:56.750 align:middle line:84% Here's the percentage of hygienic bees, 00:20:56.750 --> 00:21:00.250 align:middle line:84% and the 100n means 100% non-hygienic, 00:21:00.250 --> 00:21:02.530 align:middle line:90% so that's 0% hygienic bees. 00:21:02.530 --> 00:21:05.620 align:middle line:90% 00:21:05.620 --> 00:21:08.170 align:middle line:84% Here they're just listing the number of bees that 00:21:08.170 --> 00:21:09.810 align:middle line:90% are hygienic or nonhygienic. 00:21:09.810 --> 00:21:11.860 align:middle line:84% The nonhygienic ones are in parentheses. 00:21:11.860 --> 00:21:14.170 align:middle line:84% You'll see that there are 1,600 bees. 00:21:14.170 --> 00:21:16.760 align:middle line:84% They adjusted the numbers in these four colonies-- 00:21:16.760 --> 00:21:21.840 align:middle line:84% so there are 1,600 bees in each of the four colonies. 00:21:21.840 --> 00:21:27.210 align:middle line:84% They went from being all hygienic and no hygienic, 00:21:27.210 --> 00:21:29.800 align:middle line:84% and then the in between ones here-- 00:21:29.800 --> 00:21:34.780 align:middle line:90% 400 and 1,200, and 800 and 800. 00:21:34.780 --> 00:21:40.720 align:middle line:84% Then here's the statistics on how many of them are actually 00:21:40.720 --> 00:21:42.780 align:middle line:90% engaging in hygienic behavior. 00:21:42.780 --> 00:21:46.260 align:middle line:84% You can see that if only 25% of them were hygienic, 00:21:46.260 --> 00:21:53.290 align:middle line:84% then almost 79% of them engaged in hygienic behavior. 00:21:53.290 --> 00:22:02.320 align:middle line:84% If half of them were hygienic, then almost 40% 00:22:02.320 --> 00:22:07.070 align:middle line:84% If all of them were hygienic, only about 19% of them 00:22:07.070 --> 00:22:11.060 align:middle line:84% would engage in hygienic behavior in this study. 00:22:11.060 --> 00:22:17.470 align:middle line:84% Of course, if none of them were hygienic, 00:22:17.470 --> 00:22:22.690 align:middle line:84% then they are only looking at the hygienic behavior 00:22:22.690 --> 00:22:24.980 align:middle line:90% of the two kinds of bees. 00:22:24.980 --> 00:22:28.420 align:middle line:84% But they looked at the nonhygienic behavior-- 00:22:28.420 --> 00:22:41.450 align:middle line:84% sorry, nonhygienic behavior in hygienic and nonhygienic bees. 00:22:41.450 --> 00:22:44.610 align:middle line:84% It's very interesting, the nonhygienic bees actually 00:22:44.610 --> 00:22:49.120 align:middle line:84% do engage in some hygienic behavior, 00:22:49.120 --> 00:22:52.990 align:middle line:84% so that doesn't quite fit the genetic study. 00:22:52.990 --> 00:22:55.590 align:middle line:84% That led me to look a little further, 00:22:55.590 --> 00:22:57.190 align:middle line:90% and I found another paper. 00:22:57.190 --> 00:22:59.680 align:middle line:84% It included one of the same authors, 00:22:59.680 --> 00:23:02.330 align:middle line:90% which is how I found it. 00:23:02.330 --> 00:23:04.830 align:middle line:84% It was published the same year in the Journal of Comparative 00:23:04.830 --> 00:23:10.210 align:middle line:84% Physiology, and it was entitled "Olfactory and Behavioral 00:23:10.210 --> 00:23:17.230 align:middle line:84% Response Thresholds to Odors of Disease Brood Differ Between 00:23:17.230 --> 00:23:19.122 align:middle line:84% Hygienic and Nonhygienic Honey Bees." 00:23:19.122 --> 00:23:20.580 align:middle line:84% They had a couple of different ways 00:23:20.580 --> 00:23:23.367 align:middle line:84% of looking at how sensitive they were to odors. 00:23:23.367 --> 00:23:25.450 align:middle line:84% They were interested, of course, in their response 00:23:25.450 --> 00:23:30.100 align:middle line:84% to the odor of dying or dead larvae, 00:23:30.100 --> 00:23:35.370 align:middle line:84% and they found that the hygienic and nonhygienic bees 00:23:35.370 --> 00:23:37.370 align:middle line:90% showed different thresholds. 00:23:37.370 --> 00:23:41.810 align:middle line:84% The hygienic bees were much more sensitive to the odor. 00:23:41.810 --> 00:23:47.180 align:middle line:84% They had inherited different olfactory abilities. 00:23:47.180 --> 00:23:51.640 align:middle line:84% But it wasn't that the nonhygienic bees couldn't 00:23:51.640 --> 00:23:54.860 align:middle line:84% detect the odor of the dying larvae. 00:23:54.860 --> 00:23:57.157 align:middle line:84% They just had much higher thresholds, 00:23:57.157 --> 00:23:58.990 align:middle line:84% so it was more difficult for them to detect. 00:23:58.990 --> 00:24:04.510 align:middle line:90% 00:24:04.510 --> 00:24:08.880 align:middle line:84% So that may explain why the nonhygienic bees sometimes 00:24:08.880 --> 00:24:11.900 align:middle line:84% do clean out a cell of dead larvae. 00:24:11.900 --> 00:24:17.220 align:middle line:84% They not only can smell, just not as well. 00:24:17.220 --> 00:24:19.570 align:middle line:84% But they can also engage in hygienic behavior, 00:24:19.570 --> 00:24:22.230 align:middle line:90% if they actually detect it. 00:24:22.230 --> 00:24:25.140 align:middle line:84% But usually they're not engaging in such behavior, 00:24:25.140 --> 00:24:27.930 align:middle line:90% because they don't notice it. 00:24:27.930 --> 00:24:30.780 align:middle line:84% That's probably much more efficient for a bee colony. 00:24:30.780 --> 00:24:33.730 align:middle line:90% 00:24:33.730 --> 00:24:36.640 align:middle line:84% You don't need all bees doing that. 00:24:36.640 --> 00:24:38.100 align:middle line:84% What you need the rest of them for? 00:24:38.100 --> 00:24:39.630 align:middle line:84% These are worker bees, and you want 00:24:39.630 --> 00:24:44.720 align:middle line:84% them to go out and get the nectar, 00:24:44.720 --> 00:24:47.880 align:middle line:84% bring it back to the hive, feed those larvae, 00:24:47.880 --> 00:24:50.700 align:middle line:84% because most of them, of course, are alive, 00:24:50.700 --> 00:24:55.290 align:middle line:84% unless the colony is suffering from some pathology, which 00:24:55.290 --> 00:24:56.490 align:middle line:90% does occur in bees. 00:24:56.490 --> 00:25:00.020 align:middle line:90% 00:25:00.020 --> 00:25:04.500 align:middle line:84% The study completely neglected the topic 00:25:04.500 --> 00:25:06.490 align:middle line:90% that Scott had emphasized-- 00:25:06.490 --> 00:25:11.390 align:middle line:84% the difference between uncapping and removal behavior. 00:25:11.390 --> 00:25:13.870 align:middle line:84% This later study, in spite of one of the authors 00:25:13.870 --> 00:25:17.310 align:middle line:84% being the same, they didn't mention that. 00:25:17.310 --> 00:25:21.790 align:middle line:84% I'm not going to make any attempt to reconcile that. 00:25:21.790 --> 00:25:24.940 align:middle line:90% This is typical in science. 00:25:24.940 --> 00:25:27.750 align:middle line:84% They don't completely satisfy you with any study, 00:25:27.750 --> 00:25:31.820 align:middle line:84% but it did explain quite a bit about why some bees engage 00:25:31.820 --> 00:25:33.240 align:middle line:84% in the behavior and others don't. 00:25:33.240 --> 00:25:39.310 align:middle line:90% 00:25:39.310 --> 00:25:41.830 align:middle line:84% A little more about genes and behavior-- 00:25:41.830 --> 00:25:45.370 align:middle line:90% we talk about genetic fitness. 00:25:45.370 --> 00:25:46.600 align:middle line:90% What is genetic fitness? 00:25:46.600 --> 00:25:50.040 align:middle line:90% 00:25:50.040 --> 00:25:56.910 align:middle line:84% Direct genetic fitness means how many offspring you have. 00:25:56.910 --> 00:26:00.710 align:middle line:84% That's one measure of your genetic fitness. 00:26:00.710 --> 00:26:03.235 align:middle line:84% We can also talk about inclusive fitness. 00:26:03.235 --> 00:26:07.760 align:middle line:90% 00:26:07.760 --> 00:26:10.870 align:middle line:84% How do we define inclusive fitness? 00:26:10.870 --> 00:26:19.180 align:middle line:84% It was a major issue for Charles Darwin, this issue. 00:26:19.180 --> 00:26:24.300 align:middle line:84% How could sterile workers evolve in social insects? 00:26:24.300 --> 00:26:28.810 align:middle line:84% Sterile workers are not having offspring. 00:26:28.810 --> 00:26:37.630 align:middle line:84% Sterile workers are the daughters of a queen, 00:26:37.630 --> 00:26:43.550 align:middle line:84% but they share a lot of genes with that queen. 00:26:43.550 --> 00:26:51.920 align:middle line:84% In fact, because of the genetics of these hymenoptera, 00:26:51.920 --> 00:26:55.820 align:middle line:84% they usually share 75% with the mother. 00:26:55.820 --> 00:26:59.660 align:middle line:84% That depends, if she only mated with one male anyway. 00:26:59.660 --> 00:27:02.770 align:middle line:84% We'll come back to this topic when we deal with sociobiology. 00:27:02.770 --> 00:27:05.280 align:middle line:84% It's been a major topic, and it's 00:27:05.280 --> 00:27:08.050 align:middle line:84% led to a number of new findings by a sociobiologist. 00:27:08.050 --> 00:27:10.580 align:middle line:90% 00:27:10.580 --> 00:27:16.440 align:middle line:84% The point is because of the work of those sterile workers, 00:27:16.440 --> 00:27:19.320 align:middle line:84% their work for the colony, promotes the survival 00:27:19.320 --> 00:27:23.130 align:middle line:84% and increase in their genes, which they share 00:27:23.130 --> 00:27:26.010 align:middle line:90% with their mother, the queen. 00:27:26.010 --> 00:27:30.690 align:middle line:90% They have inclusive fitness. 00:27:30.690 --> 00:27:34.130 align:middle line:84% Similarly, if you have a human who has no offspring, 00:27:34.130 --> 00:27:37.140 align:middle line:84% it doesn't mean that his inclusive fitness-- 00:27:37.140 --> 00:27:40.800 align:middle line:84% the broader definition of genetic fitness-- 00:27:40.800 --> 00:27:41.420 align:middle line:90% isn't present. 00:27:41.420 --> 00:27:45.150 align:middle line:84% If he is doing something to promote 00:27:45.150 --> 00:27:48.130 align:middle line:84% the survival of his nieces and nephews, 00:27:48.130 --> 00:27:54.990 align:middle line:84% for example, of his sister, whatever you see, 00:27:54.990 --> 00:27:57.570 align:middle line:84% he's promoting the survival of his own genes. 00:27:57.570 --> 00:28:04.400 align:middle line:90% He shares 50% with his siblings. 00:28:04.400 --> 00:28:08.740 align:middle line:84% He shares 25% with his nieces and nephews. 00:28:08.740 --> 00:28:11.470 align:middle line:84% That's why the concept of inclusive fitness 00:28:11.470 --> 00:28:12.430 align:middle line:90% is so important. 00:28:12.430 --> 00:28:16.460 align:middle line:84% It's, in fact, necessary to explain the evolution 00:28:16.460 --> 00:28:20.950 align:middle line:90% of specific types of behavior. 00:28:20.950 --> 00:28:27.960 align:middle line:90% 00:28:27.960 --> 00:28:30.170 align:middle line:84% Let's say a little bit about learning, and starting 00:28:30.170 --> 00:28:32.365 align:middle line:84% with very simple kinds of learning-- habituation 00:28:32.365 --> 00:28:35.990 align:middle line:90% and sensory adaptation. 00:28:35.990 --> 00:28:39.642 align:middle line:84% You should know the definitions of habituation 00:28:39.642 --> 00:28:40.975 align:middle line:90% and sensory adaptation. 00:28:40.975 --> 00:28:43.550 align:middle line:90% 00:28:43.550 --> 00:28:48.170 align:middle line:84% Scott's textbook describes briefly just habitation, not 00:28:48.170 --> 00:28:51.400 align:middle line:90% sensory adaptation. 00:28:51.400 --> 00:28:54.370 align:middle line:84% You can easily find an answer to that, 00:28:54.370 --> 00:28:56.820 align:middle line:84% and you should be able to give definitions of habituation. 00:28:56.820 --> 00:29:02.710 align:middle line:90% 00:29:02.710 --> 00:29:05.170 align:middle line:84% I'm asking a question there about habituation 00:29:05.170 --> 00:29:06.590 align:middle line:90% to different kinds of stimuli. 00:29:06.590 --> 00:29:09.020 align:middle line:84% Let's just start with definitions 00:29:09.020 --> 00:29:10.605 align:middle line:90% for these two terms. 00:29:10.605 --> 00:29:13.860 align:middle line:90% 00:29:13.860 --> 00:29:17.190 align:middle line:84% In both cases, there's a decreased response 00:29:17.190 --> 00:29:20.420 align:middle line:84% with repeated presentation of the same stimulus. 00:29:20.420 --> 00:29:25.410 align:middle line:90% 00:29:25.410 --> 00:29:29.400 align:middle line:84% Say I'm touching your back of your hand. 00:29:29.400 --> 00:29:32.040 align:middle line:84% I'm sitting next to you, you know me well, 00:29:32.040 --> 00:29:34.970 align:middle line:84% and I'm jiggling my hand, and I'm touching you. 00:29:34.970 --> 00:29:39.330 align:middle line:84% You notice it at the beginning, but pretty soon you 00:29:39.330 --> 00:29:40.140 align:middle line:90% habituate to it. 00:29:40.140 --> 00:29:40.670 align:middle line:90% Or did you? 00:29:40.670 --> 00:29:42.240 align:middle line:90% Maybe just adapt to it. 00:29:42.240 --> 00:29:43.968 align:middle line:90% Maybe it's sensory adaptation. 00:29:43.968 --> 00:29:44.885 align:middle line:90% What's the difference? 00:29:44.885 --> 00:29:48.390 align:middle line:90% 00:29:48.390 --> 00:29:52.230 align:middle line:84% Habituation is more central, and we 00:29:52.230 --> 00:29:54.980 align:middle line:84% can go to physiology and define it that way. 00:29:54.980 --> 00:29:59.460 align:middle line:90% 00:29:59.460 --> 00:30:06.420 align:middle line:84% It's closer to the motor side, and the level of the response 00:30:06.420 --> 00:30:09.870 align:middle line:84% depends on the degree of novelty. 00:30:09.870 --> 00:30:13.610 align:middle line:84% The more this stimulus occurs, the less and less novel 00:30:13.610 --> 00:30:15.800 align:middle line:90% it is, the more expected it is-- 00:30:15.800 --> 00:30:17.580 align:middle line:90% less and less response. 00:30:17.580 --> 00:30:20.010 align:middle line:84% In the case of sensory adaptation, the actual-- 00:30:20.010 --> 00:30:23.180 align:middle line:84% and this usually happens right at the receptor level-- 00:30:23.180 --> 00:30:25.770 align:middle line:90% 00:30:25.770 --> 00:30:27.435 align:middle line:90% you get less and less response. 00:30:27.435 --> 00:30:29.520 align:middle line:84% The receptors are just not sending 00:30:29.520 --> 00:30:32.750 align:middle line:84% as many impulses to the central nervous system. 00:30:32.750 --> 00:30:34.810 align:middle line:90% It's a kind of fatigue. 00:30:34.810 --> 00:30:40.235 align:middle line:84% That's sensory adaptation, and when the stimulus stops, 00:30:40.235 --> 00:30:41.360 align:middle line:90% there's a gradual recovery. 00:30:41.360 --> 00:30:44.590 align:middle line:90% 00:30:44.590 --> 00:30:46.420 align:middle line:90% The same is true for habitation. 00:30:46.420 --> 00:30:51.895 align:middle line:84% There is recovery, but the mechanism is very different. 00:30:51.895 --> 00:30:55.420 align:middle line:90% 00:30:55.420 --> 00:30:59.130 align:middle line:84% In the case of a habituation, it's really difficult 00:30:59.130 --> 00:31:02.298 align:middle line:84% to define it as a kind of fatigue, 00:31:02.298 --> 00:31:04.830 align:middle line:84% although people have thought of it as fatigue 00:31:04.830 --> 00:31:06.300 align:middle line:90% at the more central level. 00:31:06.300 --> 00:31:09.050 align:middle line:90% 00:31:09.050 --> 00:31:11.470 align:middle line:84% Think of examples of habituation, 00:31:11.470 --> 00:31:16.290 align:middle line:84% and tell me if you can habituate to both simple and complex 00:31:16.290 --> 00:31:16.790 align:middle line:90% stimuli. 00:31:16.790 --> 00:31:23.030 align:middle line:84% Can you habituate to several bars of Mozart? 00:31:23.030 --> 00:31:27.260 align:middle line:84% You can certainly habituate to a ticking of a clock. 00:31:27.260 --> 00:31:29.850 align:middle line:84% You can habituate to cars going by. 00:31:29.850 --> 00:31:33.470 align:middle line:84% You live on a busy street like I do, pretty soon you're 00:31:33.470 --> 00:31:34.725 align:middle line:90% ignoring most of it-- 00:31:34.725 --> 00:31:36.930 align:middle line:84% a particularly loud truck goes by, 00:31:36.930 --> 00:31:39.200 align:middle line:84% something changes, yeah you notice it, 00:31:39.200 --> 00:31:41.130 align:middle line:84% but most the time, you're not even 00:31:41.130 --> 00:31:43.680 align:middle line:84% noticing that you're habituated to it. 00:31:43.680 --> 00:31:47.130 align:middle line:84% You don't normally notice the clock. 00:31:47.130 --> 00:31:50.180 align:middle line:84% You don't notice internal sounds in your body 00:31:50.180 --> 00:31:51.750 align:middle line:90% unless they change a lot. 00:31:51.750 --> 00:31:52.960 align:middle line:90% You habituate to it. 00:31:52.960 --> 00:31:56.540 align:middle line:90% 00:31:56.540 --> 00:31:59.120 align:middle line:90% What about the bars of Mozart? 00:31:59.120 --> 00:32:01.860 align:middle line:90% Can you habituate to it? 00:32:01.860 --> 00:32:03.000 align:middle line:90% Yes you can. 00:32:03.000 --> 00:32:06.180 align:middle line:84% You can habituate to complex stimuli, too. 00:32:06.180 --> 00:32:12.150 align:middle line:84% In fact, in tests of habituation, 00:32:12.150 --> 00:32:17.170 align:middle line:84% it's when something changes that you get a new response. 00:32:17.170 --> 00:32:20.780 align:middle line:84% So in formal tests, you might use series of stimuli. 00:32:20.780 --> 00:32:24.750 align:middle line:84% They often use rhythmic stimuli, and they can then suddenly 00:32:24.750 --> 00:32:28.700 align:middle line:84% leave out one stimulus in the rhythm. 00:32:28.700 --> 00:32:32.970 align:middle line:84% It sounds different, and the animal or the person 00:32:32.970 --> 00:32:35.115 align:middle line:90% will make an orienting response. 00:32:35.115 --> 00:32:42.840 align:middle line:90% 00:32:42.840 --> 00:32:46.070 align:middle line:84% You can respond to the sudden absence of the stimulus, 00:32:46.070 --> 00:32:48.355 align:middle line:90% any detection of novelty. 00:32:48.355 --> 00:32:49.480 align:middle line:90% Now what are the responses? 00:32:49.480 --> 00:32:52.850 align:middle line:90% 00:32:52.850 --> 00:32:56.670 align:middle line:84% We won't be able to get much beyond this today. 00:32:56.670 --> 00:33:00.710 align:middle line:84% All of these terms are used in describing responses 00:33:00.710 --> 00:33:01.680 align:middle line:90% to novel stimuli-- 00:33:01.680 --> 00:33:04.840 align:middle line:84% the arousal response, the orienting response, 00:33:04.840 --> 00:33:09.600 align:middle line:84% orienting reflex is commonly used, especially in the east. 00:33:09.600 --> 00:33:12.635 align:middle line:84% This has been studied a lot in Russia. 00:33:12.635 --> 00:33:16.600 align:middle line:90% 00:33:16.600 --> 00:33:20.380 align:middle line:84% We talk about curiosity for novelty. 00:33:20.380 --> 00:33:24.310 align:middle line:84% That is also a response to novelty. 00:33:24.310 --> 00:33:28.850 align:middle line:84% There's responses at the autonomic level, 00:33:28.850 --> 00:33:30.920 align:middle line:84% involving the autonomic nervous system. 00:33:30.920 --> 00:33:32.900 align:middle line:90% What are those responses? 00:33:32.900 --> 00:33:36.580 align:middle line:84% Heart rate change-- it's usually a heart rate increase, 00:33:36.580 --> 00:33:38.470 align:middle line:84% but if the heart's beating very fast already, 00:33:38.470 --> 00:33:42.140 align:middle line:90% it will actually slow down-- 00:33:42.140 --> 00:33:50.150 align:middle line:84% altered breathing, increased muscle tension, basal dilation 00:33:50.150 --> 00:33:53.100 align:middle line:84% in the head, basal constriction in the limbs. 00:33:53.100 --> 00:33:56.240 align:middle line:84% Interesting that it's different in the head and in the limbs. 00:33:56.240 --> 00:33:58.600 align:middle line:84% In the head, where you have only head senses, 00:33:58.600 --> 00:34:03.430 align:middle line:90% it's different than the limbs. 00:34:03.430 --> 00:34:04.980 align:middle line:84% You can specifically measure that. 00:34:04.980 --> 00:34:06.690 align:middle line:84% You can measure the volume of the finger, 00:34:06.690 --> 00:34:09.489 align:middle line:84% for example, with a plethysmograph. 00:34:09.489 --> 00:34:12.812 align:middle line:84% It's easy to hook up a cuff around the finger 00:34:12.812 --> 00:34:15.760 align:middle line:84% and measure the volume and record it 00:34:15.760 --> 00:34:20.820 align:middle line:84% in a pretty sensitive way, and you will see the basal dilation 00:34:20.820 --> 00:34:22.580 align:middle line:90% or basal constriction. 00:34:22.580 --> 00:34:24.400 align:middle line:84% Then there's behavioral responses-- 00:34:24.400 --> 00:34:31.110 align:middle line:84% alerting responses-- orientation of the head, eyes, and ears. 00:34:31.110 --> 00:34:33.230 align:middle line:84% Exploratory behaviors-- so now we're 00:34:33.230 --> 00:34:37.060 align:middle line:84% not just talking about orienting and alerting. 00:34:37.060 --> 00:34:39.750 align:middle line:84% I'm talking about approach and manipulation, 00:34:39.750 --> 00:34:43.719 align:middle line:84% all behavioral responses to novelty. 00:34:43.719 --> 00:34:49.350 align:middle line:84% Then finally we have a motivation to seek novelty, 00:34:49.350 --> 00:34:51.850 align:middle line:84% especially in higher vertebrates. 00:34:51.850 --> 00:34:56.650 align:middle line:84% Exploratory behavior occurs caused by a motivation 00:34:56.650 --> 00:35:00.915 align:middle line:84% to seek novelty that we call the motivation of curiosity. 00:35:00.915 --> 00:35:03.580 align:middle line:90% 00:35:03.580 --> 00:35:08.150 align:middle line:84% I want to point out here that a novel stimulus can 00:35:08.150 --> 00:35:11.970 align:middle line:84% be seen as a conflict between expected input and perceived 00:35:11.970 --> 00:35:13.230 align:middle line:90% input. 00:35:13.230 --> 00:35:16.330 align:middle line:84% If you look at it-- this is the way a cognitive psychologist 00:35:16.330 --> 00:35:17.460 align:middle line:90% would look at it-- 00:35:17.460 --> 00:35:20.680 align:middle line:84% and it corresponds very well to what's happening-- 00:35:20.680 --> 00:35:23.860 align:middle line:90% 00:35:23.860 --> 00:35:27.730 align:middle line:84% and I point out here that the autonomic changes are exactly 00:35:27.730 --> 00:35:32.190 align:middle line:84% the same as measured by a lie detector. 00:35:32.190 --> 00:35:33.770 align:middle line:84% What does a lie detector measure? 00:35:33.770 --> 00:35:37.190 align:middle line:90% 00:35:37.190 --> 00:35:40.870 align:middle line:84% Lies cause a different kind of conflict. 00:35:40.870 --> 00:35:43.930 align:middle line:84% In both cases we're dealing with conflict, and in both cases, 00:35:43.930 --> 00:35:48.590 align:middle line:84% we get these same autonomic responses. 00:35:48.590 --> 00:35:49.930 align:middle line:90% If in a lie detection-- 00:35:49.930 --> 00:35:53.100 align:middle line:84% that's why the skill of the person administering the test 00:35:53.100 --> 00:35:54.890 align:middle line:90% is so critical. 00:35:54.890 --> 00:35:58.130 align:middle line:84% He can get the autonomic responses, just 00:35:58.130 --> 00:36:04.135 align:middle line:84% by introducing novelty, and he has to be very aware of that. 00:36:04.135 --> 00:36:10.070 align:middle line:90% 00:36:10.070 --> 00:36:14.200 align:middle line:84% We'll start by talking more about other kinds of learning, 00:36:14.200 --> 00:36:18.026 align:middle line:84% including associative learning and conditioning next time. 00:36:18.026 --> 00:36:18.526 align:middle line:90%