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 --> 00:00:21.550 align:middle line:90% 00:00:21.550 --> 00:00:23.050 align:middle line:84% PROFESSOR: In the last class we were 00:00:23.050 --> 00:00:28.000 align:middle line:84% talking about the parasitic birds that 00:00:28.000 --> 00:00:30.480 align:middle line:84% lay their eggs in the nest of another bird, 00:00:30.480 --> 00:00:32.720 align:middle line:90% and I asked you a question. 00:00:32.720 --> 00:00:36.890 align:middle line:84% Now how-- why wouldn't these other birds 00:00:36.890 --> 00:00:40.600 align:middle line:90% evolve means of opposing that? 00:00:40.600 --> 00:00:44.220 align:middle line:84% Why don't they just learn to recognize 00:00:44.220 --> 00:00:46.360 align:middle line:90% the eggs of the other bird? 00:00:46.360 --> 00:00:49.652 align:middle line:84% You can see here that in many cases 00:00:49.652 --> 00:00:54.710 align:middle line:84% you can see that much larger egg there, 00:00:54.710 --> 00:00:57.750 align:middle line:84% and yet they, generally, will raise it. 00:00:57.750 --> 00:00:58.610 align:middle line:90% Raise the chick. 00:00:58.610 --> 00:01:02.900 align:middle line:84% In fact, it's often at the expense of their own chicks, 00:01:02.900 --> 00:01:07.870 align:middle line:84% because the cuckoo is an aggressive chick. 00:01:07.870 --> 00:01:12.290 align:middle line:84% Often you know pushes the other, the smaller chicks 00:01:12.290 --> 00:01:13.300 align:middle line:90% out of the nest. 00:01:13.300 --> 00:01:19.740 align:middle line:84% And sometimes the foster mother, and in this case, 00:01:19.740 --> 00:01:22.360 align:middle line:90% is raising only the cuckoo. 00:01:22.360 --> 00:01:25.780 align:middle line:84% But at least her reproduction is considerably 00:01:25.780 --> 00:01:29.485 align:middle line:90% diminished by this problem. 00:01:29.485 --> 00:01:32.770 align:middle line:90% 00:01:32.770 --> 00:01:35.860 align:middle line:84% And one of the reasons they do it 00:01:35.860 --> 00:01:41.410 align:middle line:84% has been investigated in a study of the spotted cuckoo 00:01:41.410 --> 00:01:43.995 align:middle line:90% and magpies in Spain. 00:01:43.995 --> 00:01:48.710 align:middle line:90% 00:01:48.710 --> 00:01:59.270 align:middle line:84% At a time when the cuckoos moved into an area the magpies were 00:01:59.270 --> 00:02:02.410 align:middle line:84% living-- or the magpies moved in, I can't remember which. 00:02:02.410 --> 00:02:04.930 align:middle line:84% I think the cuckoos came in later. 00:02:04.930 --> 00:02:05.430 align:middle line:90% OK. 00:02:05.430 --> 00:02:10.620 align:middle line:84% And so they started laying their eggs in other birds' nest. 00:02:10.620 --> 00:02:14.360 align:middle line:84% But then they found out that the birds often 00:02:14.360 --> 00:02:20.600 align:middle line:90% do destroy the cuckoo's egg. 00:02:20.600 --> 00:02:26.490 align:middle line:84% But when they do, there's sort of a mag-- 00:02:26.490 --> 00:02:31.100 align:middle line:84% a cuckoo mafia that comes around and destroys their nest, 00:02:31.100 --> 00:02:33.570 align:middle line:84% so then they don't reproduce at all. 00:02:33.570 --> 00:02:40.400 align:middle line:84% And it's better to reproduce even a few than none. 00:02:40.400 --> 00:02:42.890 align:middle line:84% So that was the mafia hypothesis, 00:02:42.890 --> 00:02:47.740 align:middle line:90% and it was verified in Spain. 00:02:47.740 --> 00:02:50.260 align:middle line:90% But there have been reports-- 00:02:50.260 --> 00:02:54.970 align:middle line:84% and I don't know of any really quantitative description 00:02:54.970 --> 00:03:01.410 align:middle line:84% of this, but were cases when the song bird 00:03:01.410 --> 00:03:07.240 align:middle line:84% would build a decoy nest above his real nest 00:03:07.240 --> 00:03:09.320 align:middle line:90% and lay eggs in both. 00:03:09.320 --> 00:03:14.490 align:middle line:84% And the cuckoo generally will lay the agony-- 00:03:14.490 --> 00:03:19.130 align:middle line:84% the conspicuous nest, the nest at the top, and the next 00:03:19.130 --> 00:03:21.420 align:middle line:90% below is more hidden. 00:03:21.420 --> 00:03:23.470 align:middle line:84% But I don't know just how often that happens. 00:03:23.470 --> 00:03:27.010 align:middle line:90% 00:03:27.010 --> 00:03:31.610 align:middle line:84% But they have to do it in a way that this 00:03:31.610 --> 00:03:37.020 align:middle line:84% is group of cuckoos couldn't force them, 00:03:37.020 --> 00:03:39.380 align:middle line:84% or couldn't destroy their nest, because they 00:03:39.380 --> 00:03:42.990 align:middle line:90% destroyed their egg. 00:03:42.990 --> 00:03:44.780 align:middle line:90% So we saw this last time. 00:03:44.780 --> 00:03:48.260 align:middle line:90% 00:03:48.260 --> 00:03:52.210 align:middle line:84% Well so the cuckoo is exploiting the innate releasing 00:03:52.210 --> 00:03:58.226 align:middle line:84% mechanism of the song birds that they use to raise their young. 00:03:58.226 --> 00:04:05.040 align:middle line:84% It's because they can't resist that big gap of the cuckoo 00:04:05.040 --> 00:04:06.710 align:middle line:90% chick. 00:04:06.710 --> 00:04:11.275 align:middle line:84% It elicits feeding behavior, so they get fed. 00:04:11.275 --> 00:04:13.820 align:middle line:90% 00:04:13.820 --> 00:04:16.790 align:middle line:84% But this kind of thing happens in humans, too. 00:04:16.790 --> 00:04:22.890 align:middle line:84% We discussed earlier how the food industry and restaurants 00:04:22.890 --> 00:04:30.330 align:middle line:84% add extra fat, including saturated fat, to foods-- 00:04:30.330 --> 00:04:32.880 align:middle line:84% especially the fast food industry-- 00:04:32.880 --> 00:04:35.900 align:middle line:90% because people prefer the taste. 00:04:35.900 --> 00:04:37.250 align:middle line:90% They wanted to be fat. 00:04:37.250 --> 00:04:48.410 align:middle line:84% Think of all the people that are eating the high fat potato-- 00:04:48.410 --> 00:04:50.190 align:middle line:90% what do they call them? 00:04:50.190 --> 00:04:51.120 align:middle line:90% STUDENT: French fry? 00:04:51.120 --> 00:04:52.370 align:middle line:90% PROFESSOR: --the French fries. 00:04:52.370 --> 00:04:55.620 align:middle line:84% I never eat them, so I don't even remember their name. 00:04:55.620 --> 00:04:56.280 align:middle line:90% All right. 00:04:56.280 --> 00:04:58.230 align:middle line:84% When you're diabetic you know you really 00:04:58.230 --> 00:05:00.460 align:middle line:90% pay if you eat stuff like that. 00:05:00.460 --> 00:05:04.010 align:middle line:84% The high fat, because fat digests very slowly 00:05:04.010 --> 00:05:07.830 align:middle line:84% and it raises blood sugar for many hours afterwards. 00:05:07.830 --> 00:05:09.530 align:middle line:84% It has more than double the number 00:05:09.530 --> 00:05:13.430 align:middle line:84% of calories of protein and carbohydrate. 00:05:13.430 --> 00:05:18.210 align:middle line:84% But what-- I mentioned here the doll industry. 00:05:18.210 --> 00:05:19.810 align:middle line:90% These are pictures from-- 00:05:19.810 --> 00:05:23.130 align:middle line:90% [INAUDIBLE] one of his papers-- 00:05:23.130 --> 00:05:27.300 align:middle line:84% and some of these properties of infants 00:05:27.300 --> 00:05:30.700 align:middle line:84% were pointed out by Lorenz and how you find it 00:05:30.700 --> 00:05:32.950 align:middle line:90% in many different species-- 00:05:32.950 --> 00:05:35.550 align:middle line:84% that babies have a relatively larger head, 00:05:35.550 --> 00:05:37.460 align:middle line:90% relatively larger eyes. 00:05:37.460 --> 00:05:38.635 align:middle line:90% They have short limbs-- 00:05:38.635 --> 00:05:41.380 align:middle line:90% 00:05:41.380 --> 00:05:48.430 align:middle line:84% short usually chubby limbs, and that appearance of the baby 00:05:48.430 --> 00:05:51.250 align:middle line:90% elicits care giving. 00:05:51.250 --> 00:05:56.900 align:middle line:84% You know even a big, aggressive male 00:05:56.900 --> 00:06:00.570 align:middle line:84% will respond to babies showing these properties, 00:06:00.570 --> 00:06:03.020 align:middle line:84% especially if the baby's submitting the cute little 00:06:03.020 --> 00:06:04.330 align:middle line:90% sounds they make. 00:06:04.330 --> 00:06:08.070 align:middle line:84% We call them cute, because of these stimuli that they have, 00:06:08.070 --> 00:06:13.120 align:middle line:90% and even men are affected by it. 00:06:13.120 --> 00:06:17.800 align:middle line:84% And the doll industry uses that also in creating dolls. 00:06:17.800 --> 00:06:21.360 align:middle line:84% The cupie dolls normally made with the, again, 00:06:21.360 --> 00:06:25.010 align:middle line:84% relatively larger head and large eyes. 00:06:25.010 --> 00:06:29.570 align:middle line:84% But if you overdo that, what happens? 00:06:29.570 --> 00:06:34.610 align:middle line:84% There's a line between what's cute and what's grotesque. 00:06:34.610 --> 00:06:35.110 align:middle line:90% OK? 00:06:35.110 --> 00:06:41.760 align:middle line:84% So obviously they simply use human reactions 00:06:41.760 --> 00:06:44.430 align:middle line:84% to shape the way they design those things. 00:06:44.430 --> 00:06:47.300 align:middle line:90% 00:06:47.300 --> 00:06:47.800 align:middle line:90% OK. 00:06:47.800 --> 00:06:51.190 align:middle line:84% Now we talk about key stimuli, and we 00:06:51.190 --> 00:06:54.460 align:middle line:84% say that they can release fixed action patterns. 00:06:54.460 --> 00:06:57.120 align:middle line:90% 00:06:57.120 --> 00:07:03.390 align:middle line:84% But we don't call all key stimuli that 00:07:03.390 --> 00:07:05.760 align:middle line:84% engage the innate releasing mechanisms, 00:07:05.760 --> 00:07:10.640 align:middle line:84% we don't call them releasers generally, because that term is 00:07:10.640 --> 00:07:13.690 align:middle line:90% used somewhat differently. 00:07:13.690 --> 00:07:18.850 align:middle line:84% A releaser is a stimulus property 00:07:18.850 --> 00:07:22.890 align:middle line:84% that has evolved for the purpose of communicating, 00:07:22.890 --> 00:07:27.050 align:middle line:84% for the purpose of eliciting behavior from members 00:07:27.050 --> 00:07:28.890 align:middle line:90% of the same species. 00:07:28.890 --> 00:07:33.900 align:middle line:90% 00:07:33.900 --> 00:07:35.640 align:middle line:90% So this is the way it's defined. 00:07:35.640 --> 00:07:40.300 align:middle line:84% "A structure or a movement, most often a combination, 00:07:40.300 --> 00:07:43.970 align:middle line:84% that's evolved in the service of sending a signal." 00:07:43.970 --> 00:07:47.460 align:middle line:90% So it is they emit key stimuli. 00:07:47.460 --> 00:07:52.540 align:middle line:84% So in nature whenever you see release showy color patterns 00:07:52.540 --> 00:07:56.853 align:middle line:84% or structures, in any vertebrate. 00:07:56.853 --> 00:07:58.520 align:middle line:84% And they don't have to be invertebrates, 00:07:58.520 --> 00:08:01.910 align:middle line:84% they can be invertebrates as well. 00:08:01.910 --> 00:08:03.820 align:middle line:84% And also any louder or regular sound 00:08:03.820 --> 00:08:07.460 align:middle line:84% utterance, any regular complicated and rhythmically 00:08:07.460 --> 00:08:11.756 align:middle line:84% perform movement, like evolves in the rituals of courting. 00:08:11.756 --> 00:08:15.250 align:middle line:90% It functions as releaser. 00:08:15.250 --> 00:08:19.360 align:middle line:84% And I'm showing you the cover of Smithsonian's-- 00:08:19.360 --> 00:08:22.090 align:middle line:90% 00:08:22.090 --> 00:08:24.960 align:middle line:84% of a Smithsonian publication there that shows 00:08:24.960 --> 00:08:28.570 align:middle line:90% the hamadryas baboon face. 00:08:28.570 --> 00:08:30.200 align:middle line:90% But let's start with humans. 00:08:30.200 --> 00:08:34.320 align:middle line:84% Describe two releasers in human, one involving a motor pattern. 00:08:34.320 --> 00:08:36.223 align:middle line:90% Well that's easy, smiling. 00:08:36.223 --> 00:08:39.280 align:middle line:90% 00:08:39.280 --> 00:08:45.100 align:middle line:84% Smiling is a movement, but it's evolved because of the way it-- 00:08:45.100 --> 00:08:49.590 align:middle line:84% the stimuli it that cause a reaction in others. 00:08:49.590 --> 00:08:51.750 align:middle line:90% OK? 00:08:51.750 --> 00:08:55.970 align:middle line:84% Almost all of us respond positively to smiles. 00:08:55.970 --> 00:08:57.150 align:middle line:90% OK? 00:08:57.150 --> 00:09:00.050 align:middle line:84% And we smile whether we're aware of it or not 00:09:00.050 --> 00:09:06.100 align:middle line:84% in order to, you know, get those positive responses. 00:09:06.100 --> 00:09:09.710 align:middle line:84% What other-- Can you think of anything else? 00:09:09.710 --> 00:09:12.760 align:middle line:84% Think of babies and their parents. 00:09:12.760 --> 00:09:17.797 align:middle line:84% They've evolved not just the larger 00:09:17.797 --> 00:09:18.880 align:middle line:90% head and the short limbs-- 00:09:18.880 --> 00:09:21.380 align:middle line:84% I mean there could be various reasons for that-- but they've 00:09:21.380 --> 00:09:23.120 align:middle line:90% evolved these chubby cheeks. 00:09:23.120 --> 00:09:25.260 align:middle line:84% They actually have fat pads in their cheeks 00:09:25.260 --> 00:09:28.690 align:middle line:90% that disappear later on. 00:09:28.690 --> 00:09:36.380 align:middle line:84% They've evolved specifically to elicit a certain reaction. 00:09:36.380 --> 00:09:39.560 align:middle line:84% And there's no doubt that human breasts have 00:09:39.560 --> 00:09:42.750 align:middle line:84% a similar function, that is breasts don't have 00:09:42.750 --> 00:09:45.340 align:middle line:90% to be as large as they are. 00:09:45.340 --> 00:09:50.264 align:middle line:84% They evolved in order to elicit response. 00:09:50.264 --> 00:09:51.260 align:middle line:90% OK? 00:09:51.260 --> 00:09:55.470 align:middle line:90% So these are what releaser are. 00:09:55.470 --> 00:09:58.100 align:middle line:84% And there's of course many others you can think of, 00:09:58.100 --> 00:10:01.090 align:middle line:84% various emotional expressions and things 00:10:01.090 --> 00:10:06.220 align:middle line:84% that also have evolved as these signals, social signals 00:10:06.220 --> 00:10:09.720 align:middle line:90% of various sorts. 00:10:09.720 --> 00:10:11.740 align:middle line:84% Now when we talk about mimicry, we're 00:10:11.740 --> 00:10:13.620 align:middle line:84% usually talking about something that's 00:10:13.620 --> 00:10:16.030 align:middle line:84% evolved to affect the behavior of another species. 00:10:16.030 --> 00:10:19.030 align:middle line:84% Like the monarch butterfly has mimics, 00:10:19.030 --> 00:10:24.200 align:middle line:84% because the monarch tastes terrible. 00:10:24.200 --> 00:10:27.770 align:middle line:84% Other, you know, birds won't generally attack monarchs, 00:10:27.770 --> 00:10:29.990 align:middle line:90% because they taste bad. 00:10:29.990 --> 00:10:33.030 align:middle line:90% So they quickly learn, you know? 00:10:33.030 --> 00:10:36.530 align:middle line:84% It only takes one experience of a really horrible taste 00:10:36.530 --> 00:10:39.720 align:middle line:90% and animals won't do it again. 00:10:39.720 --> 00:10:43.510 align:middle line:84% But so other butterflies and moths 00:10:43.510 --> 00:10:48.510 align:middle line:84% have evolved to mimic the bitter tasting ones, 00:10:48.510 --> 00:10:52.440 align:middle line:84% and the same thing happens in some insects. 00:10:52.440 --> 00:10:57.960 align:middle line:84% But in some cases a species evolves some way to mimic-- 00:10:57.960 --> 00:11:02.210 align:middle line:90% 00:11:02.210 --> 00:11:05.750 align:middle line:84% a mimic that affects its own species. 00:11:05.750 --> 00:11:09.250 align:middle line:84% And these are the two examples, I like the mouth breeder fish. 00:11:09.250 --> 00:11:10.710 align:middle line:90% Let's look at that here. 00:11:10.710 --> 00:11:11.950 align:middle line:90% The mouth breeder fish. 00:11:11.950 --> 00:11:13.130 align:middle line:90% Here's the male. 00:11:13.130 --> 00:11:20.430 align:middle line:84% And if you look here at the anal fin you see the little spots. 00:11:20.430 --> 00:11:22.680 align:middle line:90% What are those orange spots? 00:11:22.680 --> 00:11:26.790 align:middle line:84% Well they look just like the eggs of the female mouth 00:11:26.790 --> 00:11:28.040 align:middle line:90% breeder. 00:11:28.040 --> 00:11:29.650 align:middle line:84% Well what does the mouth breeder do? 00:11:29.650 --> 00:11:33.610 align:middle line:84% She lays her eggs and she takes them up in her mouth. 00:11:33.610 --> 00:11:36.510 align:middle line:90% She breeds them in her mouth. 00:11:36.510 --> 00:11:39.930 align:middle line:90% So she tries to get these, too. 00:11:39.930 --> 00:11:42.590 align:middle line:90% Perfect for the male. 00:11:42.590 --> 00:11:45.060 align:middle line:84% He comes after-- she comes after the male, 00:11:45.060 --> 00:11:48.050 align:middle line:84% her mouth is there trying to get at those eggs, 00:11:48.050 --> 00:11:49.940 align:middle line:90% and what does he do? 00:11:49.940 --> 00:11:54.150 align:middle line:84% He injects semen right into her mouth. 00:11:54.150 --> 00:11:57.190 align:middle line:90% So he fertilizes her eggs. 00:11:57.190 --> 00:12:00.415 align:middle line:84% So that's why the mouth breeder fish has evolved that way. 00:12:00.415 --> 00:12:01.690 align:middle line:90% The mouth breeder male. 00:12:01.690 --> 00:12:04.690 align:middle line:90% Now let's take baboons. 00:12:04.690 --> 00:12:09.425 align:middle line:84% Here's a female olive baboon, and notice this pink patch 00:12:09.425 --> 00:12:10.620 align:middle line:90% on her rump. 00:12:10.620 --> 00:12:13.130 align:middle line:90% It's used as a signal. 00:12:13.130 --> 00:12:15.590 align:middle line:90% It's evolved to affect the male. 00:12:15.590 --> 00:12:18.980 align:middle line:84% But then look, males evolve a patch, too. 00:12:18.980 --> 00:12:20.260 align:middle line:90% And some of them-- 00:12:20.260 --> 00:12:21.820 align:middle line:84% I couldn't find a really pink one, 00:12:21.820 --> 00:12:24.930 align:middle line:84% but this one's pink only at the edge. 00:12:24.930 --> 00:12:28.125 align:middle line:84% But the hamadryas baboon, it's even more obvious. 00:12:28.125 --> 00:12:30.500 align:middle line:84% You know here's a male hamadryas baboon, 00:12:30.500 --> 00:12:33.370 align:middle line:84% and look at the pink rump on that animal. 00:12:33.370 --> 00:12:37.020 align:middle line:84% And here are two females actually presenting to a male, 00:12:37.020 --> 00:12:38.800 align:middle line:90% and you can see. 00:12:38.800 --> 00:12:40.853 align:middle line:84% You know that's what's being imitated. 00:12:40.853 --> 00:12:42.020 align:middle line:90% Well why would they do that? 00:12:42.020 --> 00:12:45.560 align:middle line:90% Why would a male do that? 00:12:45.560 --> 00:12:50.120 align:middle line:84% Because if a female appears and presents to him 00:12:50.120 --> 00:12:54.280 align:middle line:84% it totally inhibits his aggressive response. 00:12:54.280 --> 00:12:56.080 align:middle line:84% These are pretty aggressive animals. 00:12:56.080 --> 00:12:56.580 align:middle line:90% OK? 00:12:56.580 --> 00:13:00.120 align:middle line:84% And they need ways to turn off the aggression, 00:13:00.120 --> 00:13:02.760 align:middle line:84% so the males have taken advantage of that. 00:13:02.760 --> 00:13:05.580 align:middle line:84% They evolve a signal where they can turn off 00:13:05.580 --> 00:13:08.610 align:middle line:84% the aggression of a more dominant male, 00:13:08.610 --> 00:13:11.630 align:middle line:90% and it protects them. 00:13:11.630 --> 00:13:14.090 align:middle line:84% And many rodents-- many of these things 00:13:14.090 --> 00:13:15.860 align:middle line:90% are a little more subtle. 00:13:15.860 --> 00:13:21.465 align:middle line:84% You know a hamster a normal Syrian hamster-- 00:13:21.465 --> 00:13:27.380 align:middle line:84% has evolved these white patches on his chest. 00:13:27.380 --> 00:13:27.880 align:middle line:90% OK? 00:13:27.880 --> 00:13:32.000 align:middle line:84% If those are exposed it reduces the aggression of a male. 00:13:32.000 --> 00:13:32.500 align:middle line:90% OK. 00:13:32.500 --> 00:13:34.500 align:middle line:84% If he wants to attack, he actually 00:13:34.500 --> 00:13:36.940 align:middle line:90% covers them with his feet. 00:13:36.940 --> 00:13:37.440 align:middle line:90% OK? 00:13:37.440 --> 00:13:39.950 align:middle line:84% Because of the signal property that they have, 00:13:39.950 --> 00:13:42.090 align:middle line:84% and similarly their white underbelly. 00:13:42.090 --> 00:13:45.640 align:middle line:84% If they expose that, because they're defeated in a fight, 00:13:45.640 --> 00:13:50.000 align:middle line:84% it generally works pretty well to inhibit the attack 00:13:50.000 --> 00:13:51.820 align:middle line:90% so they won't get killed. 00:13:51.820 --> 00:13:55.530 align:middle line:84% The only time I've had hamster males kill or females-- 00:13:55.530 --> 00:13:57.460 align:middle line:84% they both are pretty aggressive-- 00:13:57.460 --> 00:14:02.080 align:middle line:84% kill another animal is when it's an artificial situation 00:14:02.080 --> 00:14:04.190 align:middle line:84% in a cage where the animal gets caught 00:14:04.190 --> 00:14:08.750 align:middle line:84% and he can't expose the right stimuli. 00:14:08.750 --> 00:14:14.330 align:middle line:84% Like he's caught in the wire mesh or where he's not-- 00:14:14.330 --> 00:14:17.650 align:middle line:84% they're in such close quarters, he can't, you know, 00:14:17.650 --> 00:14:20.310 align:middle line:90% actually expose those signals. 00:14:20.310 --> 00:14:21.823 align:middle line:90% All right. 00:14:21.823 --> 00:14:23.490 align:middle line:84% Just a couple of other things, and we'll 00:14:23.490 --> 00:14:25.800 align:middle line:90% get onto the next class here. 00:14:25.800 --> 00:14:28.020 align:middle line:84% I want you to know what the dummy rule is. 00:14:28.020 --> 00:14:33.440 align:middle line:84% The rule is that if you can make a simple model-- 00:14:33.440 --> 00:14:37.420 align:middle line:84% like those models of the stickleback female-- 00:14:37.420 --> 00:14:39.200 align:middle line:84% that elicits a fixed action pattern-- 00:14:39.200 --> 00:14:41.550 align:middle line:84% like following response of the male-- 00:14:41.550 --> 00:14:45.230 align:middle line:84% then we're dealing with an innate releasing mechanism. 00:14:45.230 --> 00:14:48.650 align:middle line:84% Something that has-- on the sensory side-- 00:14:48.650 --> 00:14:51.850 align:middle line:84% that's evolved to respond to those stimuli. 00:14:51.850 --> 00:14:57.100 align:middle line:84% But if you can't find a dummy stimulus that works, 00:14:57.100 --> 00:15:00.770 align:middle line:84% it doesn't mean there's no innate releasing mechanism. 00:15:00.770 --> 00:15:05.070 align:middle line:84% And the reason is this, learning. 00:15:05.070 --> 00:15:10.550 align:middle line:84% The usual role of learning in animals, 00:15:10.550 --> 00:15:12.660 align:middle line:84% it does affect instinctive behavior. 00:15:12.660 --> 00:15:13.440 align:middle line:90% And the way it-- 00:15:13.440 --> 00:15:16.550 align:middle line:84% It usually doesn't affect the motor side very much. 00:15:16.550 --> 00:15:19.530 align:middle line:84% Different motor patterns can be linked in specific ways 00:15:19.530 --> 00:15:22.580 align:middle line:84% as we've talked about with the attack behavior, 00:15:22.580 --> 00:15:24.990 align:middle line:90% predatory attack in cats. 00:15:24.990 --> 00:15:28.450 align:middle line:84% They do have to put the various individual fix 00:15:28.450 --> 00:15:30.430 align:middle line:90% motor patterns together. 00:15:30.430 --> 00:15:30.930 align:middle line:90% OK? 00:15:30.930 --> 00:15:33.230 align:middle line:90% They learn that. 00:15:33.230 --> 00:15:35.640 align:middle line:84% But the selectivity of the stimuli 00:15:35.640 --> 00:15:38.450 align:middle line:84% that elicit the fixed action pattern 00:15:38.450 --> 00:15:40.680 align:middle line:90% can be increased with learning. 00:15:40.680 --> 00:15:41.180 align:middle line:90% OK? 00:15:41.180 --> 00:15:46.670 align:middle line:84% So in imprinting you see that happening. 00:15:46.670 --> 00:15:50.390 align:middle line:84% It can change with the experience of the animal. 00:15:50.390 --> 00:15:52.530 align:middle line:84% But even an animal that doesn't have to imprint, 00:15:52.530 --> 00:15:55.010 align:middle line:84% he responds innately to something. 00:15:55.010 --> 00:15:59.550 align:middle line:84% Like a novel box moved overhead above turkeys 00:15:59.550 --> 00:16:05.290 align:middle line:84% can elicit the anti-predatory response of crouching 00:16:05.290 --> 00:16:08.726 align:middle line:84% and freezing, but that can become more specific 00:16:08.726 --> 00:16:09.393 align:middle line:90% with experience. 00:16:09.393 --> 00:16:16.770 align:middle line:90% 00:16:16.770 --> 00:16:17.300 align:middle line:90% OK. 00:16:17.300 --> 00:16:20.460 align:middle line:84% Now this will take us the rest of this hour and Monday. 00:16:20.460 --> 00:16:24.050 align:middle line:90% 00:16:24.050 --> 00:16:27.860 align:middle line:84% I want to go through the theoretical models of fixed 00:16:27.860 --> 00:16:30.360 align:middle line:84% action patterns, and the innate releasing 00:16:30.360 --> 00:16:34.150 align:middle line:84% mechanisms of Lorenz and Tinbergen, 00:16:34.150 --> 00:16:37.580 align:middle line:90% which have been the major ones. 00:16:37.580 --> 00:16:43.980 align:middle line:84% And you can easily see how their models can be put into computer 00:16:43.980 --> 00:16:48.020 align:middle line:90% models using information flow. 00:16:48.020 --> 00:16:52.240 align:middle line:84% And that has been done fairly successfully. 00:16:52.240 --> 00:16:55.120 align:middle line:84% The second thing is the hierarchy and chains 00:16:55.120 --> 00:16:57.680 align:middle line:90% of behavior. 00:16:57.680 --> 00:17:02.510 align:middle line:84% The hierarchical organization of instinctive behavior. 00:17:02.510 --> 00:17:09.520 align:middle line:84% And then spatial orientation by reflexes, 00:17:09.520 --> 00:17:11.050 align:middle line:90% and an internal model. 00:17:11.050 --> 00:17:12.220 align:middle line:90% We'll talk about that. 00:17:12.220 --> 00:17:15.099 align:middle line:84% And then finally what happens when 00:17:15.099 --> 00:17:19.430 align:middle line:84% there are multiple motivations arise simultaneously? 00:17:19.430 --> 00:17:20.940 align:middle line:90% And that happens very commonly. 00:17:20.940 --> 00:17:26.829 align:middle line:84% And sometimes two motivations can be almost equally strong. 00:17:26.829 --> 00:17:28.190 align:middle line:90% How does an animal handle that? 00:17:28.190 --> 00:17:30.490 align:middle line:90% 00:17:30.490 --> 00:17:30.990 align:middle line:90% OK. 00:17:30.990 --> 00:17:36.370 align:middle line:90% So Lorenz' model we call-- 00:17:36.370 --> 00:17:38.950 align:middle line:84% it's sometimes been called a psycho-hydraulic model. 00:17:38.950 --> 00:17:42.500 align:middle line:84% It's really a sort of hydraulic mechanical model 00:17:42.500 --> 00:17:47.680 align:middle line:84% of the motivational state, the action specific potential 00:17:47.680 --> 00:17:49.210 align:middle line:90% in his terms. 00:17:49.210 --> 00:17:50.360 align:middle line:90% And he had two models. 00:17:50.360 --> 00:17:52.290 align:middle line:90% He changed it after awhile. 00:17:52.290 --> 00:17:55.840 align:middle line:84% On the left, there you see his old model. 00:17:55.840 --> 00:18:01.490 align:middle line:84% The action specific potential was represented as reservoir. 00:18:01.490 --> 00:18:06.780 align:middle line:84% The endogenous stimulus-- that is an internal stimulus-- 00:18:06.780 --> 00:18:10.260 align:middle line:84% is always there, and so it's gradually building up 00:18:10.260 --> 00:18:14.620 align:middle line:90% that level until its released. 00:18:14.620 --> 00:18:19.740 align:middle line:84% And he has the release there by the-- 00:18:19.740 --> 00:18:23.160 align:middle line:84% he throws this mechanical thing where the spring there 00:18:23.160 --> 00:18:26.300 align:middle line:84% represents some kind of inertia of the system. 00:18:26.300 --> 00:18:32.680 align:middle line:84% But the releasing stimuli there caused the discharge 00:18:32.680 --> 00:18:34.800 align:middle line:90% of that fluid. 00:18:34.800 --> 00:18:38.090 align:middle line:84% But then his observations on animals 00:18:38.090 --> 00:18:42.460 align:middle line:84% made him realize that it's not accurate enough, 00:18:42.460 --> 00:18:45.130 align:middle line:90% so he revised it. 00:18:45.130 --> 00:18:52.480 align:middle line:84% And he realized that there's not only this endogenous input 00:18:52.480 --> 00:18:55.850 align:middle line:90% that's gradually building up-- 00:18:55.850 --> 00:18:58.870 align:middle line:84% like our tendency to blink our eyes gradually 00:18:58.870 --> 00:19:00.130 align:middle line:90% builds up until we blink. 00:19:00.130 --> 00:19:02.738 align:middle line:84% And we do it spontaneously, and we don't even think about it. 00:19:02.738 --> 00:19:04.280 align:middle line:84% Unless right now I'm conscious of it, 00:19:04.280 --> 00:19:06.030 align:middle line:84% and I realized that I've now blinked twice 00:19:06.030 --> 00:19:08.110 align:middle line:90% since I started talking. 00:19:08.110 --> 00:19:08.610 align:middle line:90% OK. 00:19:08.610 --> 00:19:11.120 align:middle line:84% But he's got other stimuli there, too. 00:19:11.120 --> 00:19:16.190 align:middle line:84% And these are, he calls, readiness increasing stimuli. 00:19:16.190 --> 00:19:20.510 align:middle line:84% They are stimuli that don't act quite like the releasing-- 00:19:20.510 --> 00:19:23.100 align:middle line:84% they're not adequate to actually release the movement, 00:19:23.100 --> 00:19:26.370 align:middle line:84% but they do increase the motivation. 00:19:26.370 --> 00:19:28.430 align:middle line:90% OK? 00:19:28.430 --> 00:19:32.200 align:middle line:84% And you can think how many of those could be learned. 00:19:32.200 --> 00:19:33.940 align:middle line:84% But then the releasing stimulus-- 00:19:33.940 --> 00:19:36.760 align:middle line:90% 00:19:36.760 --> 00:19:44.250 align:middle line:84% the key stimuli that caused the discharge of the fixed motor 00:19:44.250 --> 00:19:45.070 align:middle line:90% pattern-- 00:19:45.070 --> 00:19:49.580 align:middle line:84% is like just pouring more fluid rapidly into the cup. 00:19:49.580 --> 00:19:53.350 align:middle line:84% So he sees the releasing stimuli as just something that 00:19:53.350 --> 00:19:57.625 align:middle line:84% raises the motivation to a high level, and it does so rapidly. 00:19:57.625 --> 00:20:01.070 align:middle line:90% 00:20:01.070 --> 00:20:05.020 align:middle line:84% And I've defined the various things there below. 00:20:05.020 --> 00:20:08.160 align:middle line:84% Now the major difference, of course, 00:20:08.160 --> 00:20:14.660 align:middle line:84% is the way the releasing stimuli are acting, as I pointed out. 00:20:14.660 --> 00:20:15.450 align:middle line:90% And the-- 00:20:15.450 --> 00:20:18.490 align:middle line:90% 00:20:18.490 --> 00:20:21.980 align:middle line:84% Where these things are in the CNS-- 00:20:21.980 --> 00:20:24.890 align:middle line:84% this is very far from any kind CNS model. 00:20:24.890 --> 00:20:26.540 align:middle line:90% It's an analogous model. 00:20:26.540 --> 00:20:27.040 align:middle line:90% OK? 00:20:27.040 --> 00:20:30.270 align:middle line:90% 00:20:30.270 --> 00:20:37.300 align:middle line:84% It's a hydraulic mechanical model that unfortunately looks 00:20:37.300 --> 00:20:39.910 align:middle line:84% more like a flush toilet than other things you can think of, 00:20:39.910 --> 00:20:46.270 align:middle line:84% and so sometimes Lorenz was made fun of for this. 00:20:46.270 --> 00:20:49.840 align:middle line:84% But in fact the model was useful in that it pointed out 00:20:49.840 --> 00:20:50.900 align:middle line:90% properties. 00:20:50.900 --> 00:20:53.400 align:middle line:84% He's basically summarizing properties 00:20:53.400 --> 00:20:55.980 align:middle line:84% that he observed for many different fixed action 00:20:55.980 --> 00:20:57.570 align:middle line:90% patterns. 00:20:57.570 --> 00:20:59.460 align:middle line:84% And the one on the right does a better job 00:20:59.460 --> 00:21:00.502 align:middle line:90% than the one on the left. 00:21:00.502 --> 00:21:03.310 align:middle line:90% 00:21:03.310 --> 00:21:06.280 align:middle line:84% Now if we talk about where these things are in the brain, 00:21:06.280 --> 00:21:07.650 align:middle line:90% it's interesting. 00:21:07.650 --> 00:21:12.460 align:middle line:90% Because if we go here-- 00:21:12.460 --> 00:21:14.960 align:middle line:84% Now let's say you're stimulating the spinal cord 00:21:14.960 --> 00:21:16.192 align:middle line:90% or the hindbrain. 00:21:16.192 --> 00:21:20.240 align:middle line:84% You can get various components of fixed motor patterns. 00:21:20.240 --> 00:21:21.860 align:middle line:90% OK? 00:21:21.860 --> 00:21:26.430 align:middle line:84% But generally only when the stimulus is on, you get them. 00:21:26.430 --> 00:21:31.980 align:middle line:84% So it's not acting at all like the action specific potential 00:21:31.980 --> 00:21:37.160 align:middle line:84% in the reservoir here where you get the whole sequence. 00:21:37.160 --> 00:21:37.660 align:middle line:90% OK? 00:21:37.660 --> 00:21:40.690 align:middle line:90% 00:21:40.690 --> 00:21:44.160 align:middle line:84% And when you suddenly take the stimulus away, 00:21:44.160 --> 00:21:48.000 align:middle line:84% the action doesn't just suddenly stop, just like in the model. 00:21:48.000 --> 00:21:54.800 align:middle line:90% 00:21:54.800 --> 00:21:57.240 align:middle line:90% So I just summarized that here. 00:21:57.240 --> 00:21:59.330 align:middle line:84% For low levels, the behavioral changes 00:21:59.330 --> 00:22:04.160 align:middle line:84% occur only during the periods of stimulation, then they stop. 00:22:04.160 --> 00:22:06.070 align:middle line:84% And in fact if you have an animal that's 00:22:06.070 --> 00:22:09.150 align:middle line:84% had a transection of the higher of the brain-- 00:22:09.150 --> 00:22:11.240 align:middle line:90% they've been totally separated. 00:22:11.240 --> 00:22:12.480 align:middle line:90% They're no longer influence-- 00:22:12.480 --> 00:22:14.850 align:middle line:84% the hypothalamic region, the whole forebrain 00:22:14.850 --> 00:22:18.380 align:middle line:84% is cut off from those lower regions-- 00:22:18.380 --> 00:22:21.480 align:middle line:84% you can still stimulate fixed action patterns, but only 00:22:21.480 --> 00:22:22.450 align:middle line:90% the motor component. 00:22:22.450 --> 00:22:24.450 align:middle line:84% And they just stop immediately, just 00:22:24.450 --> 00:22:27.160 align:middle line:84% like the effects of electrical stimulation of those lower 00:22:27.160 --> 00:22:29.920 align:middle line:90% levels. 00:22:29.920 --> 00:22:32.910 align:middle line:84% But when you stimulate in the caudal forebrain there, 00:22:32.910 --> 00:22:35.010 align:middle line:84% the hypothalamic area, then you do 00:22:35.010 --> 00:22:40.380 align:middle line:84% elicit moods that are very, very hard 00:22:40.380 --> 00:22:45.960 align:middle line:84% to distinguish from the mood that would occur normally. 00:22:45.960 --> 00:22:49.190 align:middle line:90% 00:22:49.190 --> 00:22:53.720 align:middle line:84% And that's been done for both the quiet, biting attack-- 00:22:53.720 --> 00:23:00.160 align:middle line:84% the predatory attack-- of a cat, and for the more aggressive 00:23:00.160 --> 00:23:01.510 align:middle line:90% defensive attack. 00:23:01.510 --> 00:23:03.100 align:middle line:84% And you are all familiar with that. 00:23:03.100 --> 00:23:08.000 align:middle line:84% The cat that arches its back, you know and extends its claws 00:23:08.000 --> 00:23:10.490 align:middle line:90% and makes a lot of noise. 00:23:10.490 --> 00:23:11.200 align:middle line:90% OK? 00:23:11.200 --> 00:23:13.890 align:middle line:84% We call the other one a quiet biting attack, 00:23:13.890 --> 00:23:16.680 align:middle line:90% because he does not make noise. 00:23:16.680 --> 00:23:20.090 align:middle line:84% It's designed specifically to kill prey. 00:23:20.090 --> 00:23:24.980 align:middle line:90% 00:23:24.980 --> 00:23:28.610 align:middle line:84% So I'm just pointing out I want you 00:23:28.610 --> 00:23:32.490 align:middle line:84% to give examples of the effects of the inertia of excitation 00:23:32.490 --> 00:23:33.335 align:middle line:90% in animal behavior. 00:23:33.335 --> 00:23:36.960 align:middle line:90% 00:23:36.960 --> 00:23:39.120 align:middle line:84% Think of an example from human behavior, 00:23:39.120 --> 00:23:41.760 align:middle line:90% but it occurs with animals, too. 00:23:41.760 --> 00:23:43.600 align:middle line:84% You suddenly remove the stimulus-- 00:23:43.600 --> 00:23:45.530 align:middle line:90% you elicit the whole-- 00:23:45.530 --> 00:23:48.300 align:middle line:84% you increase the level of motivation 00:23:48.300 --> 00:23:52.200 align:middle line:84% that-- remember Lorenz' model on the right there. 00:23:52.200 --> 00:23:57.140 align:middle line:84% You cause the motivation to go way, way up. 00:23:57.140 --> 00:24:00.580 align:middle line:84% If you just suddenly remove that stimulus, 00:24:00.580 --> 00:24:03.950 align:middle line:84% the behavior doesn't just go away. 00:24:03.950 --> 00:24:05.820 align:middle line:90% OK? 00:24:05.820 --> 00:24:09.590 align:middle line:84% I like the example from a Disney movie of a bear. 00:24:09.590 --> 00:24:13.880 align:middle line:84% They show the bear that's high on a hill, 00:24:13.880 --> 00:24:16.700 align:middle line:84% and he's trying to get something in a log-- a big log. 00:24:16.700 --> 00:24:19.585 align:middle line:84% And he crawls in to the log as far as he can get, 00:24:19.585 --> 00:24:21.250 align:middle line:90% and he gets stuck there. 00:24:21.250 --> 00:24:24.920 align:middle line:84% And then the log starts rolling downhill. 00:24:24.920 --> 00:24:29.690 align:middle line:84% Bonding downhill until finally it crashes against a tree 00:24:29.690 --> 00:24:31.340 align:middle line:90% and breaks open the log. 00:24:31.340 --> 00:24:35.770 align:middle line:84% And the bear comes out angry as can be. 00:24:35.770 --> 00:24:37.480 align:middle line:90% And he starts swatting. 00:24:37.480 --> 00:24:39.690 align:middle line:90% He pulls little trees. 00:24:39.690 --> 00:24:42.580 align:middle line:84% You know just like an angry human, 00:24:42.580 --> 00:24:45.270 align:middle line:84% that you don't get over it suddenly, 00:24:45.270 --> 00:24:46.970 align:middle line:90% even if the stimuli are gone. 00:24:46.970 --> 00:24:50.162 align:middle line:90% 00:24:50.162 --> 00:24:52.700 align:middle line:84% If something on the TV makes you very angry, 00:24:52.700 --> 00:24:54.905 align:middle line:84% some people have been known to break their TV. 00:24:54.905 --> 00:24:58.360 align:middle line:90% 00:24:58.360 --> 00:25:02.650 align:middle line:84% This is the inertia of excitation of a fixed action 00:25:02.650 --> 00:25:09.410 align:middle line:84% pattern by this change in the motivational level here 00:25:09.410 --> 00:25:11.160 align:middle line:90% on the right. 00:25:11.160 --> 00:25:14.100 align:middle line:84% You can remove that stimulus there, 00:25:14.100 --> 00:25:19.100 align:middle line:84% but the reservoir is so full that the action continues 00:25:19.100 --> 00:25:19.935 align:middle line:90% for some time. 00:25:19.935 --> 00:25:23.150 align:middle line:90% 00:25:23.150 --> 00:25:23.670 align:middle line:90% All right. 00:25:23.670 --> 00:25:28.310 align:middle line:90% 00:25:28.310 --> 00:25:30.680 align:middle line:84% So you see that with fear, with aggression, 00:25:30.680 --> 00:25:32.720 align:middle line:84% with sexual excitement, certainly. 00:25:32.720 --> 00:25:35.290 align:middle line:84% These are the areas certainly in human behavior, 00:25:35.290 --> 00:25:40.840 align:middle line:84% but also in many animals that you see that the most. 00:25:40.840 --> 00:25:44.880 align:middle line:84% How can we explain the fact that the urination activities 00:25:44.880 --> 00:25:48.390 align:middle line:84% of a male dog often don't depend on the amount of urine 00:25:48.390 --> 00:25:49.485 align:middle line:90% in the bladder? 00:25:49.485 --> 00:25:50.860 align:middle line:84% You say, well, why do we urinate? 00:25:50.860 --> 00:25:54.980 align:middle line:84% Well we have an urge to urinate, because the bladder's full. 00:25:54.980 --> 00:26:00.890 align:middle line:84% But in the case of a dog, urination has other functions. 00:26:00.890 --> 00:26:05.240 align:middle line:84% So there's two very different motivations that make, 00:26:05.240 --> 00:26:08.200 align:middle line:90% at least, the male dog urinate. 00:26:08.200 --> 00:26:11.320 align:middle line:90% In the case of female cats-- 00:26:11.320 --> 00:26:12.570 align:middle line:90% in the case of cats-- 00:26:12.570 --> 00:26:13.890 align:middle line:90% I don't know about-- 00:26:13.890 --> 00:26:16.880 align:middle line:90% I don't think dogs-- 00:26:16.880 --> 00:26:19.230 align:middle line:90% But what are they doing? 00:26:19.230 --> 00:26:20.560 align:middle line:90% Why do they hold back? 00:26:20.560 --> 00:26:24.810 align:middle line:84% They don't discharge all their urine. 00:26:24.810 --> 00:26:28.080 align:middle line:84% They need it for scent marking behavior, 00:26:28.080 --> 00:26:31.450 align:middle line:90% so that's a separate motivation. 00:26:31.450 --> 00:26:33.160 align:middle line:90% OK? 00:26:33.160 --> 00:26:38.440 align:middle line:84% And cats do it, too, both male and female, 00:26:38.440 --> 00:26:40.320 align:middle line:90% because of the odor. 00:26:40.320 --> 00:26:42.900 align:middle line:84% These are very olfactory animals, 00:26:42.900 --> 00:26:48.290 align:middle line:84% and their whole world is very different from ours. 00:26:48.290 --> 00:26:53.500 align:middle line:84% It is visual and auditory, like ours, but much more olfactory. 00:26:53.500 --> 00:26:57.350 align:middle line:84% They come into an area, they know 00:26:57.350 --> 00:27:00.340 align:middle line:84% which other cats, which individual cats 00:27:00.340 --> 00:27:02.500 align:middle line:84% have been in that region, and whether they 00:27:02.500 --> 00:27:04.060 align:middle line:90% were male or female. 00:27:04.060 --> 00:27:04.560 align:middle line:90% OK? 00:27:04.560 --> 00:27:05.670 align:middle line:90% And they leave their mark. 00:27:05.670 --> 00:27:08.790 align:middle line:90% 00:27:08.790 --> 00:27:10.350 align:middle line:90% Humans sometimes do that, too. 00:27:10.350 --> 00:27:13.415 align:middle line:84% They write on walls and things like that. 00:27:13.415 --> 00:27:13.915 align:middle line:90% OK. 00:27:13.915 --> 00:27:21.230 align:middle line:90% 00:27:21.230 --> 00:27:24.080 align:middle line:84% Let's talk about chains of behavior, 00:27:24.080 --> 00:27:28.770 align:middle line:84% and then the hierarchy of the systems of fixed action 00:27:28.770 --> 00:27:30.300 align:middle line:90% patterns. 00:27:30.300 --> 00:27:34.090 align:middle line:84% So as an example here I'm asking for a description 00:27:34.090 --> 00:27:36.400 align:middle line:84% of the chain of behavior patterns shown 00:27:36.400 --> 00:27:39.420 align:middle line:84% by newborn kittens in nursing behavior. 00:27:39.420 --> 00:27:40.420 align:middle line:90% It's very interesting. 00:27:40.420 --> 00:27:45.510 align:middle line:84% It's a consistent chain of behavior that they show. 00:27:45.510 --> 00:27:48.980 align:middle line:84% And normally one behavior leads to the next, 00:27:48.980 --> 00:27:51.840 align:middle line:84% because it leads to the stimulus that elicits the next. 00:27:51.840 --> 00:27:53.990 align:middle line:90% And I've listed them here. 00:27:53.990 --> 00:27:57.080 align:middle line:84% If he's awake, and he's not suckling, 00:27:57.080 --> 00:28:01.190 align:middle line:84% he shows this constant to and fro sideways sweeping movement 00:28:01.190 --> 00:28:07.770 align:middle line:84% of the head and foreparts of the body while he creeps forward. 00:28:07.770 --> 00:28:12.070 align:middle line:84% I know, of course, he's normally near the mother. 00:28:12.070 --> 00:28:14.830 align:middle line:84% And if he touches a solid vertical surface, 00:28:14.830 --> 00:28:17.810 align:middle line:84% even if it's not the mother, he snuggles up to it 00:28:17.810 --> 00:28:23.090 align:middle line:84% and maintains contact while he continues that sweeping motion. 00:28:23.090 --> 00:28:26.020 align:middle line:84% It's designed, of course-- even though it's a fixed motor 00:28:26.020 --> 00:28:28.030 align:middle line:90% pattern-- 00:28:28.030 --> 00:28:32.500 align:middle line:84% it's designed to find the teat of the mother. 00:28:32.500 --> 00:28:36.110 align:middle line:84% So if he contacts fur, he stops his forward motion. 00:28:36.110 --> 00:28:37.410 align:middle line:90% OK? 00:28:37.410 --> 00:28:39.790 align:middle line:84% But he continues the sweeping motions, his nose 00:28:39.790 --> 00:28:40.835 align:middle line:90% pressed against the fur. 00:28:40.835 --> 00:28:44.740 align:middle line:84% If he touches a bare spot, then he ceases the sweeping motion, 00:28:44.740 --> 00:28:47.290 align:middle line:84% and initiates a different behavior. 00:28:47.290 --> 00:28:49.050 align:middle line:90% He's kind of snapping. 00:28:49.050 --> 00:28:51.365 align:middle line:84% He's trying to get the teat in his mouth. 00:28:51.365 --> 00:28:54.830 align:middle line:84% So he finds it, he stops his other movements, 00:28:54.830 --> 00:28:57.970 align:middle line:84% and that initiates the suckling behavior. 00:28:57.970 --> 00:28:59.790 align:middle line:90% Sucking behavior. 00:28:59.790 --> 00:29:02.860 align:middle line:84% And also milk treading while he's sucking. 00:29:02.860 --> 00:29:04.915 align:middle line:84% You see this movement of the front paws. 00:29:04.915 --> 00:29:09.600 align:middle line:90% 00:29:09.600 --> 00:29:13.420 align:middle line:84% So each motor pattern serves as appetitive behaviour 00:29:13.420 --> 00:29:15.270 align:middle line:84% for the next fixed action pattern. 00:29:15.270 --> 00:29:17.850 align:middle line:90% 00:29:17.850 --> 00:29:22.990 align:middle line:84% Or I would say the next component of the sequence, 00:29:22.990 --> 00:29:24.495 align:middle line:90% because these are always linked. 00:29:24.495 --> 00:29:27.310 align:middle line:90% 00:29:27.310 --> 00:29:33.290 align:middle line:84% But Lorenz sees them as a very different fixed action 00:29:33.290 --> 00:29:39.005 align:middle line:84% patterns, because, in fact, you don't have 00:29:39.005 --> 00:29:40.130 align:middle line:90% to have the whole sequence. 00:29:40.130 --> 00:29:43.430 align:middle line:84% If you put the animal right next to the mother, 00:29:43.430 --> 00:29:45.330 align:middle line:84% the he won't show the earlier components. 00:29:45.330 --> 00:29:49.510 align:middle line:84% He does not have to go through the earlier ones, 00:29:49.510 --> 00:29:53.070 align:middle line:84% because they're all somewhat independent fixed action 00:29:53.070 --> 00:29:53.570 align:middle line:90% patterns. 00:29:53.570 --> 00:29:56.225 align:middle line:84% But they're normally linked because of the situation. 00:29:56.225 --> 00:30:00.130 align:middle line:90% 00:30:00.130 --> 00:30:03.280 align:middle line:84% And Tinbergen had described these kinds of things 00:30:03.280 --> 00:30:08.830 align:middle line:84% as examples of the hierarchical organization of instinct. 00:30:08.830 --> 00:30:12.030 align:middle line:84% And he has some very well known diagrams 00:30:12.030 --> 00:30:13.630 align:middle line:84% that you should be familiar with. 00:30:13.630 --> 00:30:16.620 align:middle line:90% 00:30:16.620 --> 00:30:18.840 align:middle line:84% He shows a view of innate releasing 00:30:18.840 --> 00:30:22.970 align:middle line:84% mechanisms that are quite a bit different from Lorenz. 00:30:22.970 --> 00:30:26.030 align:middle line:84% They did work together some, but they had a different way 00:30:26.030 --> 00:30:28.350 align:middle line:90% of picturing it. 00:30:28.350 --> 00:30:31.330 align:middle line:84% And you can see that he doesn't explain some of the aspects 00:30:31.330 --> 00:30:32.750 align:middle line:90% that Lorenz was dealing with. 00:30:32.750 --> 00:30:35.940 align:middle line:84% All that stuff about the inertia behavior and so forth, 00:30:35.940 --> 00:30:37.950 align:middle line:90% he didn't try to deal with. 00:30:37.950 --> 00:30:40.070 align:middle line:84% But he did deal with the hierarchy. 00:30:40.070 --> 00:30:43.205 align:middle line:84% In this case we just take one component of it. 00:30:43.205 --> 00:30:43.705 align:middle line:90% OK? 00:30:43.705 --> 00:30:48.860 align:middle line:90% 00:30:48.860 --> 00:30:55.550 align:middle line:90% And this is just for example. 00:30:55.550 --> 00:30:59.560 align:middle line:84% We're dealing with an aspect of reproductive behavior. 00:30:59.560 --> 00:31:01.485 align:middle line:90% Hormones provide a major input. 00:31:01.485 --> 00:31:04.890 align:middle line:90% 00:31:04.890 --> 00:31:09.340 align:middle line:84% The higher level could be coming from the visual system that 00:31:09.340 --> 00:31:10.740 align:middle line:90% signals the time of year. 00:31:10.740 --> 00:31:14.070 align:middle line:90% 00:31:14.070 --> 00:31:17.440 align:middle line:84% Other input that increase that motivation. 00:31:17.440 --> 00:31:22.740 align:middle line:84% And then, unlike Lorenz, he has a block 00:31:22.740 --> 00:31:26.520 align:middle line:84% preventing the continuous discharge of the motor 00:31:26.520 --> 00:31:28.100 align:middle line:90% patterns. 00:31:28.100 --> 00:31:29.600 align:middle line:84% And the innate releasing mechanism-- 00:31:29.600 --> 00:31:32.710 align:middle line:90% 00:31:32.710 --> 00:31:35.580 align:middle line:84% and then the stimulus that activates the innate releasing 00:31:35.580 --> 00:31:36.580 align:middle line:90% mechanism-- 00:31:36.580 --> 00:31:39.550 align:middle line:84% its function is simply to remove that block. 00:31:39.550 --> 00:31:42.610 align:middle line:84% And then the block, once it's removed, 00:31:42.610 --> 00:31:46.040 align:middle line:90% can elicit a whole series. 00:31:46.040 --> 00:31:47.585 align:middle line:90% And which one would be first? 00:31:47.585 --> 00:31:49.210 align:middle line:84% Well the one with the lowest threshold, 00:31:49.210 --> 00:31:52.250 align:middle line:84% and normally that's appetitive behavior. 00:31:52.250 --> 00:31:52.750 align:middle line:90% OK. 00:31:52.750 --> 00:31:56.900 align:middle line:84% And these different components of the fixed action pattern 00:31:56.900 --> 00:31:59.190 align:middle line:84% are normally inhibiting each other. 00:31:59.190 --> 00:32:02.260 align:middle line:84% And this shows a more complete model 00:32:02.260 --> 00:32:05.650 align:middle line:84% where he shows a male stickleback 00:32:05.650 --> 00:32:07.350 align:middle line:90% reproductive behavior. 00:32:07.350 --> 00:32:10.410 align:middle line:84% Basically the whole hierarchy starting with hormones 00:32:10.410 --> 00:32:13.310 align:middle line:90% with the spring migration. 00:32:13.310 --> 00:32:17.130 align:middle line:84% The nature of the water has an influence, 00:32:17.130 --> 00:32:20.370 align:middle line:84% the plants in the vicinity, and various internal factors. 00:32:20.370 --> 00:32:22.060 align:middle line:90% And then there's the block. 00:32:22.060 --> 00:32:24.950 align:middle line:84% The innate releasing mechanisms that can remove the block 00:32:24.950 --> 00:32:27.810 align:middle line:84% and start these various behaviors. 00:32:27.810 --> 00:32:30.500 align:middle line:84% And note he has the mutual inhibition shown 00:32:30.500 --> 00:32:33.090 align:middle line:90% by the double arrows here. 00:32:33.090 --> 00:32:36.170 align:middle line:84% He has fighting, nesting, courtship, 00:32:36.170 --> 00:32:40.320 align:middle line:84% and parental behavior, each with somewhat different stimuli. 00:32:40.320 --> 00:32:43.020 align:middle line:84% And so depending on the stimuli there, 00:32:43.020 --> 00:32:45.820 align:middle line:90% these will be discharged. 00:32:45.820 --> 00:32:49.060 align:middle line:84% And then he shows the lower levels, too. 00:32:49.060 --> 00:32:51.050 align:middle line:90% The level of the actual action. 00:32:51.050 --> 00:32:54.095 align:middle line:84% So here for fighting behavior he has the displaying, the biting, 00:32:54.095 --> 00:32:55.750 align:middle line:90% and the chasing. 00:32:55.750 --> 00:32:56.250 align:middle line:90% OK? 00:32:56.250 --> 00:32:59.920 align:middle line:84% And if you get the display purring, 00:32:59.920 --> 00:33:03.180 align:middle line:84% then you get whole fins, raise of one 00:33:03.180 --> 00:33:08.850 align:middle line:84% fin, muscle fibers of one ray, and motor neurons. 00:33:08.850 --> 00:33:11.430 align:middle line:90% For when the muscle fiber-- 00:33:11.430 --> 00:33:13.470 align:middle line:84% So he shows the whole hierarchy here. 00:33:13.470 --> 00:33:16.200 align:middle line:84% And this is often reproduced, because-- 00:33:16.200 --> 00:33:18.820 align:middle line:84% Neuroscientists like it because it sort of fits 00:33:18.820 --> 00:33:23.440 align:middle line:84% the hierarchical organization of the nervous system. 00:33:23.440 --> 00:33:26.230 align:middle line:84% And this shows a functional picture of that. 00:33:26.230 --> 00:33:29.160 align:middle line:90% 00:33:29.160 --> 00:33:29.660 align:middle line:90% OK. 00:33:29.660 --> 00:33:30.160 align:middle line:90% And I'm-- 00:33:30.160 --> 00:33:32.780 align:middle line:90% 00:33:32.780 --> 00:33:34.920 align:middle line:84% This is the level of ethology up here, 00:33:34.920 --> 00:33:36.755 align:middle line:84% and you are at the level of neurophysiology. 00:33:36.755 --> 00:33:39.710 align:middle line:84% They study different aspects of it. 00:33:39.710 --> 00:33:43.000 align:middle line:84% But in fact the physiologist working on hypothalamus 00:33:43.000 --> 00:33:46.360 align:middle line:84% have also studied many of these things. 00:33:46.360 --> 00:33:50.590 align:middle line:90% 00:33:50.590 --> 00:33:53.760 align:middle line:84% So the major difference then between the Lorenz model 00:33:53.760 --> 00:33:58.560 align:middle line:84% and the Tinbergen model I've listed for you here. 00:33:58.560 --> 00:34:01.200 align:middle line:84% Obviously Tinbergen's view was the broader one. 00:34:01.200 --> 00:34:04.340 align:middle line:90% 00:34:04.340 --> 00:34:08.020 align:middle line:84% It looks more like an information flow scheme. 00:34:08.020 --> 00:34:12.790 align:middle line:84% But Lorenz by focusing on the dynamics of the drive 00:34:12.790 --> 00:34:15.340 align:middle line:84% state, the action specific potential, and the innate 00:34:15.340 --> 00:34:23.000 align:middle line:84% releasing mechanism it's showing very different aspects 00:34:23.000 --> 00:34:27.310 align:middle line:84% of the properties of innate behavior. 00:34:27.310 --> 00:34:29.665 align:middle line:84% And here I just point out the strengths and weaknesses. 00:34:29.665 --> 00:34:34.080 align:middle line:90% 00:34:34.080 --> 00:34:38.330 align:middle line:84% And I also note that Tinbergen's model has been more popular 00:34:38.330 --> 00:34:40.260 align:middle line:90% among the neural people. 00:34:40.260 --> 00:34:43.130 align:middle line:90% 00:34:43.130 --> 00:34:46.719 align:middle line:84% But it was the Lorenz view that was actually 00:34:46.719 --> 00:34:50.235 align:middle line:84% used in the modeling of real behavior patterns in animals. 00:34:50.235 --> 00:34:53.600 align:middle line:90% 00:34:53.600 --> 00:34:57.340 align:middle line:84% In the work of Bruce Blumberg here at MIT when 00:34:57.340 --> 00:34:59.660 align:middle line:84% he was doing that in the media lab. 00:34:59.660 --> 00:35:00.160 align:middle line:90% OK. 00:35:00.160 --> 00:35:04.580 align:middle line:90% 00:35:04.580 --> 00:35:10.120 align:middle line:84% So let's go to the discussion of Lorenz-- 00:35:10.120 --> 00:35:11.590 align:middle line:90% of the work of [INAUDIBLE]. 00:35:11.590 --> 00:35:14.640 align:middle line:84% And this is his work on the female digger wasp, 00:35:14.640 --> 00:35:17.620 align:middle line:84% because it points out another aspect of innate behavior 00:35:17.620 --> 00:35:19.740 align:middle line:90% that I think is quite important. 00:35:19.740 --> 00:35:23.740 align:middle line:84% And this-- We're going to come back to the digger wasp 00:35:23.740 --> 00:35:27.440 align:middle line:84% next week when we read a little bit 00:35:27.440 --> 00:35:33.070 align:middle line:84% from Tinbergen and his studies of orienting 00:35:33.070 --> 00:35:35.140 align:middle line:90% behavior in that wasp. 00:35:35.140 --> 00:35:38.760 align:middle line:90% How does he find things? 00:35:38.760 --> 00:35:39.260 align:middle line:90% OK. 00:35:39.260 --> 00:35:48.160 align:middle line:84% So he's doing experiments on the influence of inspections 00:35:48.160 --> 00:35:51.000 align:middle line:90% of the nest by the wasp. 00:35:51.000 --> 00:35:54.470 align:middle line:84% It's a behavior that has a lot of plasticity. 00:35:54.470 --> 00:35:55.900 align:middle line:90% OK? 00:35:55.900 --> 00:36:01.366 align:middle line:84% And this is what the digger wasp is like. 00:36:01.366 --> 00:36:03.690 align:middle line:84% And note there's a hole in the sand. 00:36:03.690 --> 00:36:07.700 align:middle line:84% And she's made that hole, and it's basically a nest. 00:36:07.700 --> 00:36:12.890 align:middle line:84% She makes nests in the sand, little holes in the sand. 00:36:12.890 --> 00:36:17.030 align:middle line:84% And she digs a separate hole for every egg she lays. 00:36:17.030 --> 00:36:20.640 align:middle line:90% 00:36:20.640 --> 00:36:24.540 align:middle line:90% And she has to-- 00:36:24.540 --> 00:36:26.420 align:middle line:90% The egg will hatch. 00:36:26.420 --> 00:36:28.030 align:middle line:90% A larvae comes out. 00:36:28.030 --> 00:36:29.770 align:middle line:84% And when the larvae comes out, they 00:36:29.770 --> 00:36:32.040 align:middle line:90% have to have food right away. 00:36:32.040 --> 00:36:36.890 align:middle line:90% So she catches insects. 00:36:36.890 --> 00:36:40.550 align:middle line:84% This wasp is catching little insects and worms. 00:36:40.550 --> 00:36:44.570 align:middle line:84% And brings them-- killing them and bringing them, 00:36:44.570 --> 00:36:47.390 align:middle line:90% putting them in these nests. 00:36:47.390 --> 00:36:49.080 align:middle line:84% But she doesn't have just one nest. 00:36:49.080 --> 00:36:51.390 align:middle line:90% She has a bunch of them. 00:36:51.390 --> 00:36:56.260 align:middle line:84% And so when she comes to a nest she inspects-- 00:36:56.260 --> 00:37:00.460 align:middle line:84% Her first task is just to inspect it. 00:37:00.460 --> 00:37:06.840 align:middle line:84% And if it's already got some food there, then she goes on. 00:37:06.840 --> 00:37:13.710 align:middle line:84% And if it's empty, then she will fly off, 00:37:13.710 --> 00:37:15.040 align:middle line:90% and she will bring food back. 00:37:15.040 --> 00:37:18.620 align:middle line:84% And she has to remember which nest it was, and she does. 00:37:18.620 --> 00:37:21.390 align:middle line:90% She does it pretty accurately. 00:37:21.390 --> 00:37:23.120 align:middle line:90% OK? 00:37:23.120 --> 00:37:25.350 align:middle line:84% And she can have a lot of different nests. 00:37:25.350 --> 00:37:27.445 align:middle line:84% So when you look at the whole situation 00:37:27.445 --> 00:37:30.700 align:middle line:84% it seems like quite complex behavior that obviously 00:37:30.700 --> 00:37:32.150 align:middle line:90% involves some learning. 00:37:32.150 --> 00:37:36.750 align:middle line:84% And yet the whole structure is innate behavior, 00:37:36.750 --> 00:37:38.760 align:middle line:84% but with these specific things she 00:37:38.760 --> 00:37:41.935 align:middle line:84% has to remember in order to carry out the whole sequence. 00:37:41.935 --> 00:37:46.470 align:middle line:90% 00:37:46.470 --> 00:37:49.950 align:middle line:84% So what she detects in a nest determines her next behavior. 00:37:49.950 --> 00:37:52.710 align:middle line:84% Looks like my words didn't all copy there. 00:37:52.710 --> 00:37:55.220 align:middle line:90% 00:37:55.220 --> 00:37:59.140 align:middle line:84% So the behavior sequences are complicated by the fact 00:37:59.140 --> 00:38:00.890 align:middle line:84% that she digs and uses multiple nests. 00:38:00.890 --> 00:38:06.360 align:middle line:90% 00:38:06.360 --> 00:38:11.460 align:middle line:84% And that led in general motivational states underlying 00:38:11.460 --> 00:38:14.110 align:middle line:84% the feeding behavior of chicks and geese 00:38:14.110 --> 00:38:19.190 align:middle line:84% also show this relative hierarchy of moods. 00:38:19.190 --> 00:38:22.360 align:middle line:84% And a good example is the feeding 00:38:22.360 --> 00:38:25.550 align:middle line:84% of ducks, which we talked about that a little bit. 00:38:25.550 --> 00:38:28.415 align:middle line:84% But we didn't describe this behavior, the upending behavior 00:38:28.415 --> 00:38:29.540 align:middle line:90% of ducks and geese. 00:38:29.540 --> 00:38:31.650 align:middle line:90% What's upending? 00:38:31.650 --> 00:38:35.830 align:middle line:84% Have you ever watched ducks or geese feeding in a pond? 00:38:35.830 --> 00:38:39.130 align:middle line:84% Much of the time you only see their tail. 00:38:39.130 --> 00:38:41.080 align:middle line:90% They're upended. 00:38:41.080 --> 00:38:43.880 align:middle line:84% They're looking for something down below. 00:38:43.880 --> 00:38:44.800 align:middle line:90% OK? 00:38:44.800 --> 00:38:47.970 align:middle line:90% And that's how they feed. 00:38:47.970 --> 00:38:54.600 align:middle line:84% If you feed the geese, or the ducks, on the ground then 00:38:54.600 --> 00:38:55.850 align:middle line:90% they wouldn't have to do that. 00:38:55.850 --> 00:38:56.656 align:middle line:90% Right? 00:38:56.656 --> 00:39:00.850 align:middle line:84% Ah, but they're highly motivated to do upending. 00:39:00.850 --> 00:39:03.700 align:middle line:90% See it's a separate motivation. 00:39:03.700 --> 00:39:08.940 align:middle line:84% So if you deprive them of food, they will go out and upend. 00:39:08.940 --> 00:39:10.302 align:middle line:90% OK? 00:39:10.302 --> 00:39:15.130 align:middle line:84% They're not-- They're feeding because they want to upend. 00:39:15.130 --> 00:39:17.410 align:middle line:84% They're not upending in order to feed. 00:39:17.410 --> 00:39:19.650 align:middle line:84% And that's similar to what we talked about 00:39:19.650 --> 00:39:24.110 align:middle line:84% before when we talked about the starling poking into things. 00:39:24.110 --> 00:39:26.420 align:middle line:84% He's so highly motivated to poke, 00:39:26.420 --> 00:39:28.460 align:middle line:84% that even if he's well fed, he will do it. 00:39:28.460 --> 00:39:32.320 align:middle line:84% And similarly the cactus finch would still find a cactus spine 00:39:32.320 --> 00:39:33.805 align:middle line:90% and poke into things. 00:39:33.805 --> 00:39:36.180 align:middle line:84% Because he's highly-- even if he's well fed, because he's 00:39:36.180 --> 00:39:37.530 align:middle line:90% highly motivated to do that. 00:39:37.530 --> 00:39:40.700 align:middle line:90% 00:39:40.700 --> 00:39:45.330 align:middle line:84% So well fed birds deprived of upending-- 00:39:45.330 --> 00:39:48.420 align:middle line:90% we'll do that. 00:39:48.420 --> 00:39:52.500 align:middle line:84% Here's the picture of what it looks like. 00:39:52.500 --> 00:39:53.390 align:middle line:90% Two ducks upending. 00:39:53.390 --> 00:39:59.540 align:middle line:90% 00:39:59.540 --> 00:40:02.730 align:middle line:84% And I just point out here that the action specific potential 00:40:02.730 --> 00:40:06.127 align:middle line:84% for that behavior is separate than for hunger. 00:40:06.127 --> 00:40:08.750 align:middle line:90% 00:40:08.750 --> 00:40:11.675 align:middle line:84% So to deprive them of it, they will show the behavior. 00:40:11.675 --> 00:40:15.370 align:middle line:90% 00:40:15.370 --> 00:40:17.590 align:middle line:84% Lorenz has this interesting little discussion 00:40:17.590 --> 00:40:20.330 align:middle line:90% of why the head-- 00:40:20.330 --> 00:40:23.780 align:middle line:84% which he says contains the locus of superior command-- 00:40:23.780 --> 00:40:28.320 align:middle line:90% had to be invented in evolution. 00:40:28.320 --> 00:40:29.440 align:middle line:90% So how is the function-- 00:40:29.440 --> 00:40:33.070 align:middle line:90% 00:40:33.070 --> 00:40:35.360 align:middle line:84% I'm asking, has the function of the head ganglion 00:40:35.360 --> 00:40:37.395 align:middle line:84% changed in higher vertebrates with respect 00:40:37.395 --> 00:40:40.140 align:middle line:90% to fixed action patterns? 00:40:40.140 --> 00:40:41.810 align:middle line:84% And that's an interesting question. 00:40:41.810 --> 00:40:45.390 align:middle line:84% Lorenz says the head had to evolve to limit behavior 00:40:45.390 --> 00:40:46.785 align:middle line:90% to one motor pattern at a time. 00:40:46.785 --> 00:40:52.710 align:middle line:90% 00:40:52.710 --> 00:40:56.020 align:middle line:84% It was to embody the innate releasing mechanisms also, 00:40:56.020 --> 00:40:58.650 align:middle line:84% because most innate releasing mechanisms involve 00:40:58.650 --> 00:41:00.750 align:middle line:90% stimuli coming into the head. 00:41:00.750 --> 00:41:04.680 align:middle line:84% And the stimuli come in through the cranial nerves. 00:41:04.680 --> 00:41:08.040 align:middle line:84% Most of them do not come in through the spinal nerves. 00:41:08.040 --> 00:41:10.450 align:middle line:90% OK? 00:41:10.450 --> 00:41:14.560 align:middle line:84% There are some components, for example in that nursing 00:41:14.560 --> 00:41:18.750 align:middle line:84% behavior of the kitten looking for the opportunity 00:41:18.750 --> 00:41:21.855 align:middle line:84% to nurse that do come in through the spinal cord. 00:41:21.855 --> 00:41:23.855 align:middle line:84% But most of them are coming in through the head. 00:41:23.855 --> 00:41:27.950 align:middle line:90% 00:41:27.950 --> 00:41:29.760 align:middle line:84% And I'm asking here how the function has 00:41:29.760 --> 00:41:32.000 align:middle line:90% changed in higher vertebrates? 00:41:32.000 --> 00:41:35.950 align:middle line:84% I would say that the main thing that's been changing 00:41:35.950 --> 00:41:38.410 align:middle line:84% is increased linkage between innate 00:41:38.410 --> 00:41:39.890 align:middle line:90% and learned aspects of behavior. 00:41:39.890 --> 00:41:43.410 align:middle line:84% And that reaches a peak in humans, 00:41:43.410 --> 00:41:47.360 align:middle line:84% but it's very prominent in other animals. 00:41:47.360 --> 00:41:51.800 align:middle line:84% And the other is initiation of behavior patterns 00:41:51.800 --> 00:41:54.210 align:middle line:90% by learned motivations. 00:41:54.210 --> 00:41:56.674 align:middle line:90% Motivations can be learned. 00:41:56.674 --> 00:41:57.500 align:middle line:90% OK? 00:41:57.500 --> 00:42:01.220 align:middle line:84% And acquired motivations are common. 00:42:01.220 --> 00:42:04.660 align:middle line:84% We all know about, of course, some of the bad ones, 00:42:04.660 --> 00:42:06.920 align:middle line:90% the addictive behaviors. 00:42:06.920 --> 00:42:08.710 align:middle line:84% But there are many different motivations. 00:42:08.710 --> 00:42:12.290 align:middle line:84% We become highly motivated to do certain tasks. 00:42:12.290 --> 00:42:12.790 align:middle line:90% OK? 00:42:12.790 --> 00:42:14.590 align:middle line:90% Well that was not-- 00:42:14.590 --> 00:42:19.030 align:middle line:84% we didn't carry that with us from the uterus. 00:42:19.030 --> 00:42:19.530 align:middle line:90% OK? 00:42:19.530 --> 00:42:23.820 align:middle line:90% 00:42:23.820 --> 00:42:30.300 align:middle line:84% But also our cognitive level, we contain a model of the world. 00:42:30.300 --> 00:42:32.180 align:middle line:90% And in that we make-- 00:42:32.180 --> 00:42:34.750 align:middle line:84% embodies choices we make and so forth. 00:42:34.750 --> 00:42:41.240 align:middle line:90% 00:42:41.240 --> 00:42:43.660 align:middle line:84% I just point out here that the cognitive level 00:42:43.660 --> 00:42:47.430 align:middle line:84% is at the top of a neural hierarchy. 00:42:47.430 --> 00:42:50.400 align:middle line:84% But it doesn't mean just because it's at the top 00:42:50.400 --> 00:42:52.290 align:middle line:90% that it's always dominant. 00:42:52.290 --> 00:42:54.460 align:middle line:90% And we all know that for sure. 00:42:54.460 --> 00:42:58.510 align:middle line:84% People can be totally dominated by the drive 00:42:58.510 --> 00:43:06.590 align:middle line:84% to enact revenge, drive to feed, drive to acquire things. 00:43:06.590 --> 00:43:08.940 align:middle line:84% These are innate behavior patterns. 00:43:08.940 --> 00:43:17.110 align:middle line:84% And that cognitive level that's often not at the top. 00:43:17.110 --> 00:43:21.500 align:middle line:84% Maybe in true intellectuals it is. 00:43:21.500 --> 00:43:25.935 align:middle line:84% I define a true intellectual as somebody who, by what he knows 00:43:25.935 --> 00:43:28.530 align:middle line:90% and what he learns-- 00:43:28.530 --> 00:43:30.580 align:middle line:84% the cognitions that he acquires-- 00:43:30.580 --> 00:43:34.230 align:middle line:84% actually affect his behavior in a major way. 00:43:34.230 --> 00:43:37.400 align:middle line:90% It's not true of most people. 00:43:37.400 --> 00:43:42.360 align:middle line:84% In fact when one student working with Bruce and with me 00:43:42.360 --> 00:43:46.490 align:middle line:84% here at MIT was simulating human behavior, 00:43:46.490 --> 00:43:50.850 align:middle line:84% everything in it, except for some very simple spatial 00:43:50.850 --> 00:43:53.180 align:middle line:90% things, was not learned. 00:43:53.180 --> 00:43:56.190 align:middle line:84% It was all built into the software. 00:43:56.190 --> 00:44:01.480 align:middle line:84% And yet you show the results of simulations 00:44:01.480 --> 00:44:04.080 align:middle line:84% where you see people moving around, making choices, 00:44:04.080 --> 00:44:07.175 align:middle line:84% and this and that, it looks like pretty normal human behavior. 00:44:07.175 --> 00:44:09.800 align:middle line:90% 00:44:09.800 --> 00:44:12.330 align:middle line:84% So a lot of times when we're observing human behavior, 00:44:12.330 --> 00:44:14.340 align:middle line:84% we're just looking at fixed action patterns. 00:44:14.340 --> 00:44:18.110 align:middle line:90% 00:44:18.110 --> 00:44:18.610 align:middle line:90% All right. 00:44:18.610 --> 00:44:22.160 align:middle line:90% 00:44:22.160 --> 00:44:26.445 align:middle line:84% Next topic here concerns what we call taxis and reflexes. 00:44:26.445 --> 00:44:29.330 align:middle line:84% This involves spatial orientation. 00:44:29.330 --> 00:44:32.825 align:middle line:84% And that leads to a discussion of thinking in higher animals. 00:44:32.825 --> 00:44:35.400 align:middle line:90% 00:44:35.400 --> 00:44:38.700 align:middle line:84% First of all-- and we won't have time for too much more than 00:44:38.700 --> 00:44:40.540 align:middle line:90% this-- 00:44:40.540 --> 00:44:43.280 align:middle line:84% explain how the mantle of reflexes-- 00:44:43.280 --> 00:44:49.460 align:middle line:84% the term I've used from Fromholtz and Lorenz uses it, 00:44:49.460 --> 00:44:50.010 align:middle line:90% I believe. 00:44:50.010 --> 00:44:52.540 align:middle line:90% 00:44:52.540 --> 00:44:56.718 align:middle line:84% It tends to conceal the rigidity of fixed motor patterns. 00:44:56.718 --> 00:44:57.990 align:middle line:90% You know? 00:44:57.990 --> 00:45:00.760 align:middle line:84% When we walk, for example, we know 00:45:00.760 --> 00:45:02.300 align:middle line:90% that's a fixed motor pattern. 00:45:02.300 --> 00:45:05.250 align:middle line:84% It appears at a certain age when the neural mechanisms 00:45:05.250 --> 00:45:07.350 align:middle line:90% of the spinal cord mature. 00:45:07.350 --> 00:45:10.240 align:middle line:84% And the various gaits are walking and running. 00:45:10.240 --> 00:45:13.250 align:middle line:84% The various gaits of a horse, which are multiple. 00:45:13.250 --> 00:45:15.050 align:middle line:90% They're all inherited. 00:45:15.050 --> 00:45:18.280 align:middle line:84% And yet at least, especially for humans, 00:45:18.280 --> 00:45:22.840 align:middle line:84% when we're walking around it seems to vary a lot. 00:45:22.840 --> 00:45:25.315 align:middle line:84% It depends on what we're walking on. 00:45:25.315 --> 00:45:26.970 align:middle line:90% It depends on the terrain. 00:45:26.970 --> 00:45:30.320 align:middle line:84% Even horses change the way they walk, even though-- 00:45:30.320 --> 00:45:32.720 align:middle line:84% much less than, say, the more sure footed animals 00:45:32.720 --> 00:45:35.470 align:middle line:90% like goats and donkeys. 00:45:35.470 --> 00:45:40.210 align:middle line:84% But it's being adjusted by the reflexes. 00:45:40.210 --> 00:45:41.420 align:middle line:90% You know? 00:45:41.420 --> 00:45:45.810 align:middle line:84% If I'm walking along here, I'm responding visually here, too. 00:45:45.810 --> 00:45:47.350 align:middle line:84% And I don't even look here, but I 00:45:47.350 --> 00:45:48.860 align:middle line:90% can see the edge of this table. 00:45:48.860 --> 00:45:51.710 align:middle line:84% And I will walk around it without even thinking about it. 00:45:51.710 --> 00:45:58.550 align:middle line:84% This is just an example of simple spatial orientation 00:45:58.550 --> 00:46:03.000 align:middle line:84% reflexes that alter the way the locomotion is expressed. 00:46:03.000 --> 00:46:06.040 align:middle line:84% And there's much simpler examples. 00:46:06.040 --> 00:46:08.840 align:middle line:84% Like the egg rolling behavior of the graylag goose. 00:46:08.840 --> 00:46:12.300 align:middle line:84% Every time you see a graylag goose rolling an egg back 00:46:12.300 --> 00:46:14.830 align:middle line:84% into the nest, it looks a little different 00:46:14.830 --> 00:46:16.400 align:middle line:90% than other times you see it. 00:46:16.400 --> 00:46:19.620 align:middle line:84% Because the egg is rolling this way and that. 00:46:19.620 --> 00:46:22.060 align:middle line:84% It's meeting little stones and he 00:46:22.060 --> 00:46:27.045 align:middle line:84% has to keep adjusting how he's getting his beak over the egg 00:46:27.045 --> 00:46:29.300 align:middle line:84% and pulling it back towards the nest. 00:46:29.300 --> 00:46:31.235 align:middle line:84% So it looks like it's complex, and yet it's 00:46:31.235 --> 00:46:32.550 align:middle line:90% a fixed motor pattern. 00:46:32.550 --> 00:46:34.950 align:middle line:84% That's basically the same motor pattern, 00:46:34.950 --> 00:46:39.435 align:middle line:84% but it's working at a higher level than all these reflexes 00:46:39.435 --> 00:46:41.440 align:middle line:84% that are constantly adjusting it. 00:46:41.440 --> 00:46:43.590 align:middle line:90% And the reflexes never stop. 00:46:43.590 --> 00:46:46.730 align:middle line:84% Remember they don't depend on the motivation. 00:46:46.730 --> 00:46:47.560 align:middle line:90% They always act. 00:46:47.560 --> 00:46:50.310 align:middle line:90% 00:46:50.310 --> 00:46:52.160 align:middle line:84% So it looks variable and complex, 00:46:52.160 --> 00:46:58.730 align:middle line:84% because it's superimposed on the behavior 00:46:58.730 --> 00:47:00.100 align:middle line:90% of these various reflexes. 00:47:00.100 --> 00:47:01.030 align:middle line:90% They're vestibular. 00:47:01.030 --> 00:47:02.360 align:middle line:90% They're tactile. 00:47:02.360 --> 00:47:06.000 align:middle line:90% They're visual, and so forth. 00:47:06.000 --> 00:47:09.320 align:middle line:90% 00:47:09.320 --> 00:47:11.220 align:middle line:90% Last topic. 00:47:11.220 --> 00:47:15.640 align:middle line:90% A goldfish behind a barrier. 00:47:15.640 --> 00:47:19.140 align:middle line:90% Let's say these are thick weeds. 00:47:19.140 --> 00:47:22.370 align:middle line:84% He can't swim through, but he can see through it 00:47:22.370 --> 00:47:24.755 align:middle line:84% well enough to see that there's food on the other side. 00:47:24.755 --> 00:47:28.940 align:middle line:90% 00:47:28.940 --> 00:47:30.520 align:middle line:90% How does he solve that problem? 00:47:30.520 --> 00:47:33.670 align:middle line:84% And actually goldfish do pretty well. 00:47:33.670 --> 00:47:37.220 align:middle line:90% Better than dogs actually. 00:47:37.220 --> 00:47:38.690 align:middle line:90% Here's what he does. 00:47:38.690 --> 00:47:41.740 align:middle line:90% He swims right for it. 00:47:41.740 --> 00:47:46.970 align:middle line:84% And as soon as he touches it, he's got another reflex. 00:47:46.970 --> 00:47:47.470 align:middle line:90% OK? 00:47:47.470 --> 00:47:50.080 align:middle line:84% We call it a negative thigmotaxis. 00:47:50.080 --> 00:47:54.030 align:middle line:84% A negative response to touching with his snot, and that 00:47:54.030 --> 00:47:56.020 align:middle line:90% causes him to pull back. 00:47:56.020 --> 00:47:58.690 align:middle line:84% Now of course the algorithm can vary among fish, 00:47:58.690 --> 00:48:00.420 align:middle line:90% and it's very different in dogs. 00:48:00.420 --> 00:48:02.890 align:middle line:84% But normally he will keep trying to get at the food, 00:48:02.890 --> 00:48:05.510 align:middle line:84% but he will keep moving like this 00:48:05.510 --> 00:48:09.180 align:middle line:90% until he can get at the food. 00:48:09.180 --> 00:48:11.940 align:middle line:90% So just two reflexes are enough. 00:48:11.940 --> 00:48:15.850 align:middle line:84% Positive telotaxis is what we call his moving 00:48:15.850 --> 00:48:17.320 align:middle line:90% towards the food. 00:48:17.320 --> 00:48:20.000 align:middle line:84% It's just a technical name for it, positive telotaxis. 00:48:20.000 --> 00:48:23.860 align:middle line:84% Telo means the end, taxis movement. 00:48:23.860 --> 00:48:24.560 align:middle line:90% OK? 00:48:24.560 --> 00:48:28.652 align:middle line:84% Directed towards the prey, or towards the other food 00:48:28.652 --> 00:48:29.860 align:middle line:90% that he was trying to get to. 00:48:29.860 --> 00:48:33.140 align:middle line:84% And then the negative thigmotaxis 00:48:33.140 --> 00:48:37.740 align:middle line:84% causes him to avoid the obstacles, branches, plants, 00:48:37.740 --> 00:48:39.110 align:middle line:90% so forth. 00:48:39.110 --> 00:48:40.735 align:middle line:84% So it looks like intelligent behavior. 00:48:40.735 --> 00:48:43.590 align:middle line:90% 00:48:43.590 --> 00:48:46.510 align:middle line:84% He seems to figure out how to reach the food, 00:48:46.510 --> 00:48:50.480 align:middle line:84% but in fact it's just two reflexes running on. 00:48:50.480 --> 00:48:51.530 align:middle line:90% OK? 00:48:51.530 --> 00:48:53.845 align:middle line:84% So now think about how a dog does it. 00:48:53.845 --> 00:48:57.390 align:middle line:84% And we'll come back here next time.