1 00:00:00,130 --> 00:00:01,800 The following content is provided 2 00:00:01,800 --> 00:00:04,030 under a Creative Commons license. 3 00:00:04,030 --> 00:00:06,880 Your support will help MIT OpenCourseWare continue 4 00:00:06,880 --> 00:00:10,740 to offer high quality educational resources for free. 5 00:00:10,740 --> 00:00:13,350 To make a donation or view additional materials 6 00:00:13,350 --> 00:00:17,237 from hundreds of MIT courses, visit MIT OpenCourseWare 7 00:00:17,237 --> 00:00:17,862 at ocw.mit.edu. 8 00:00:21,551 --> 00:00:23,050 PROFESSOR: In the last class we were 9 00:00:23,050 --> 00:00:28,000 talking about the parasitic birds that 10 00:00:28,000 --> 00:00:30,480 lay their eggs in the nest of another bird, 11 00:00:30,480 --> 00:00:32,720 and I asked you a question. 12 00:00:32,720 --> 00:00:36,890 Now how-- why wouldn't these other birds 13 00:00:36,890 --> 00:00:40,600 evolve means of opposing that? 14 00:00:40,600 --> 00:00:44,220 Why don't they just learn to recognize 15 00:00:44,220 --> 00:00:46,360 the eggs of the other bird? 16 00:00:46,360 --> 00:00:49,652 You can see here that in many cases 17 00:00:49,652 --> 00:00:54,710 you can see that much larger egg there, 18 00:00:54,710 --> 00:00:57,750 and yet they, generally, will raise it. 19 00:00:57,750 --> 00:00:58,610 Raise the chick. 20 00:00:58,610 --> 00:01:02,900 In fact, it's often at the expense of their own chicks, 21 00:01:02,900 --> 00:01:07,870 because the cuckoo is an aggressive chick. 22 00:01:07,870 --> 00:01:12,290 Often you know pushes the other, the smaller chicks 23 00:01:12,290 --> 00:01:13,300 out of the nest. 24 00:01:13,300 --> 00:01:19,740 And sometimes the foster mother, and in this case, 25 00:01:19,740 --> 00:01:22,360 is raising only the cuckoo. 26 00:01:22,360 --> 00:01:25,780 But at least her reproduction is considerably 27 00:01:25,780 --> 00:01:29,485 diminished by this problem. 28 00:01:32,770 --> 00:01:35,860 And one of the reasons they do it 29 00:01:35,860 --> 00:01:41,410 has been investigated in a study of the spotted cuckoo 30 00:01:41,410 --> 00:01:43,995 and magpies in Spain. 31 00:01:48,710 --> 00:01:59,270 At a time when the cuckoos moved into an area the magpies were 32 00:01:59,270 --> 00:02:02,410 living-- or the magpies moved in, I can't remember which. 33 00:02:02,410 --> 00:02:04,931 I think the cuckoos came in later. 34 00:02:04,931 --> 00:02:05,430 OK. 35 00:02:05,430 --> 00:02:10,620 And so they started laying their eggs in other birds' nest. 36 00:02:10,620 --> 00:02:14,360 But then they found out that the birds often 37 00:02:14,360 --> 00:02:20,600 do destroy the cuckoo's egg. 38 00:02:20,600 --> 00:02:26,490 But when they do, there's sort of a mag-- 39 00:02:26,490 --> 00:02:31,100 a cuckoo mafia that comes around and destroys their nest, 40 00:02:31,100 --> 00:02:33,570 so then they don't reproduce at all. 41 00:02:33,570 --> 00:02:40,400 And it's better to reproduce even a few than none. 42 00:02:40,400 --> 00:02:42,890 So that was the mafia hypothesis, 43 00:02:42,890 --> 00:02:47,740 and it was verified in Spain. 44 00:02:47,740 --> 00:02:50,510 But there have been reports-- and I 45 00:02:50,510 --> 00:02:54,970 don't know of any really quantitative description 46 00:02:54,970 --> 00:03:03,110 of this, but were cases when the song bird would 47 00:03:03,110 --> 00:03:09,320 build a decoy nest above his real nest and lay eggs in both. 48 00:03:09,320 --> 00:03:13,020 And the cuckoo generally will lay 49 00:03:13,020 --> 00:03:18,630 the agony-- the conspicuous nest, the nest at the top, 50 00:03:18,630 --> 00:03:21,420 and the next below is more hidden. 51 00:03:21,420 --> 00:03:23,470 But I don't know just how often that happens. 52 00:03:27,010 --> 00:03:31,610 But they have to do it in a way that this 53 00:03:31,610 --> 00:03:37,020 is group of cuckoos couldn't force them, 54 00:03:37,020 --> 00:03:39,380 or couldn't destroy their nest, because they 55 00:03:39,380 --> 00:03:42,990 destroyed their egg. 56 00:03:42,990 --> 00:03:44,780 So we saw this last time. 57 00:03:48,260 --> 00:03:52,890 Well so the cuckoo is exploiting the innate releasing mechanism 58 00:03:52,890 --> 00:03:58,226 of the song birds that they use to raise their young. 59 00:03:58,226 --> 00:04:05,040 It's because they can't resist that big gap of the cuckoo 60 00:04:05,040 --> 00:04:06,710 chick. 61 00:04:06,710 --> 00:04:11,275 It elicits feeding behavior, so they get fed. 62 00:04:13,820 --> 00:04:16,790 But this kind of thing happens in humans, too. 63 00:04:16,790 --> 00:04:22,890 We discussed earlier how the food industry and restaurants 64 00:04:22,890 --> 00:04:28,370 add extra fat, including saturated fat, 65 00:04:28,370 --> 00:04:33,760 to foods-- especially the fast food industry-- because people 66 00:04:33,760 --> 00:04:35,900 prefer the taste. 67 00:04:35,900 --> 00:04:37,250 They wanted to be fat. 68 00:04:37,250 --> 00:04:40,270 Think of all the people that are eating 69 00:04:40,270 --> 00:04:50,190 the high fat potato-- what do they call them? 70 00:04:50,190 --> 00:04:51,120 STUDENT: French fry? 71 00:04:51,120 --> 00:04:52,370 PROFESSOR: --the French fries. 72 00:04:52,370 --> 00:04:55,620 I never eat them, so I don't even remember their name. 73 00:04:55,620 --> 00:04:56,280 All right. 74 00:04:56,280 --> 00:04:58,230 When you're diabetic you know you really 75 00:04:58,230 --> 00:05:00,460 pay if you eat stuff like that. 76 00:05:00,460 --> 00:05:04,010 The high fat, because fat digests very slowly 77 00:05:04,010 --> 00:05:07,830 and it raises blood sugar for many hours afterwards. 78 00:05:07,830 --> 00:05:09,530 It has more than double the number 79 00:05:09,530 --> 00:05:13,430 of calories of protein and carbohydrate. 80 00:05:13,430 --> 00:05:18,210 But what-- I mentioned here the doll industry. 81 00:05:18,210 --> 00:05:23,130 These are pictures from-- [INAUDIBLE] one of his papers-- 82 00:05:23,130 --> 00:05:27,300 and some of these properties of infants 83 00:05:27,300 --> 00:05:30,700 were pointed out by Lorenz and how you find it 84 00:05:30,700 --> 00:05:33,710 in many different species-- that babies 85 00:05:33,710 --> 00:05:37,460 have a relatively larger head, relatively larger eyes. 86 00:05:37,460 --> 00:05:45,100 They have short limbs-- short usually chubby limbs, 87 00:05:45,100 --> 00:05:51,250 and that appearance of the baby elicits care giving. 88 00:05:51,250 --> 00:05:56,900 You know even a big, aggressive male 89 00:05:56,900 --> 00:06:00,570 will respond to babies showing these properties, 90 00:06:00,570 --> 00:06:02,300 especially if the baby's submitting 91 00:06:02,300 --> 00:06:04,330 the cute little sounds they make. 92 00:06:04,330 --> 00:06:08,070 We call them cute, because of these stimuli that they have, 93 00:06:08,070 --> 00:06:13,120 and even men are affected by it. 94 00:06:13,120 --> 00:06:17,800 And the doll industry uses that also in creating dolls. 95 00:06:17,800 --> 00:06:21,360 The cupie dolls normally made with the, again, 96 00:06:21,360 --> 00:06:25,010 relatively larger head and large eyes. 97 00:06:25,010 --> 00:06:29,570 But if you overdo that, what happens? 98 00:06:29,570 --> 00:06:34,610 There's a line between what's cute and what's grotesque. 99 00:06:34,610 --> 00:06:35,110 OK? 100 00:06:35,110 --> 00:06:41,760 So obviously they simply use human reactions 101 00:06:41,760 --> 00:06:44,430 to shape the way they design those things. 102 00:06:47,300 --> 00:06:47,800 OK. 103 00:06:47,800 --> 00:06:51,190 Now we talk about key stimuli, and we 104 00:06:51,190 --> 00:06:54,460 say that they can release fixed action patterns. 105 00:06:57,120 --> 00:07:03,390 But we don't call all key stimuli that 106 00:07:03,390 --> 00:07:05,760 engage the innate releasing mechanisms, 107 00:07:05,760 --> 00:07:08,770 we don't call them releasers generally, 108 00:07:08,770 --> 00:07:13,690 because that term is used somewhat differently. 109 00:07:13,690 --> 00:07:18,850 A releaser is a stimulus property 110 00:07:18,850 --> 00:07:22,890 that has evolved for the purpose of communicating, 111 00:07:22,890 --> 00:07:26,340 for the purpose of eliciting behavior 112 00:07:26,340 --> 00:07:28,890 from members of the same species. 113 00:07:33,900 --> 00:07:35,640 So this is the way it's defined. 114 00:07:35,640 --> 00:07:40,300 "A structure or a movement, most often a combination, 115 00:07:40,300 --> 00:07:43,970 that's evolved in the service of sending a signal." 116 00:07:43,970 --> 00:07:47,460 So it is they emit key stimuli. 117 00:07:47,460 --> 00:07:52,540 So in nature whenever you see release showy color patterns 118 00:07:52,540 --> 00:07:56,854 or structures, in any vertebrate. 119 00:07:56,854 --> 00:07:58,520 And they don't have to be invertebrates, 120 00:07:58,520 --> 00:08:01,910 they can be invertebrates as well. 121 00:08:01,910 --> 00:08:03,820 And also any louder or regular sound 122 00:08:03,820 --> 00:08:07,460 utterance, any regular complicated and rhythmically 123 00:08:07,460 --> 00:08:11,756 perform movement, like evolves in the rituals of courting. 124 00:08:11,756 --> 00:08:15,250 It functions as releaser. 125 00:08:15,250 --> 00:08:22,560 And I'm showing you the cover of Smithsonian's-- of a 126 00:08:22,560 --> 00:08:26,370 Smithsonian publication there that shows the hamadryas baboon 127 00:08:26,370 --> 00:08:28,570 face. 128 00:08:28,570 --> 00:08:30,200 But let's start with humans. 129 00:08:30,200 --> 00:08:34,320 Describe two releasers in human, one involving a motor pattern. 130 00:08:34,320 --> 00:08:36,223 Well that's easy, smiling. 131 00:08:39,280 --> 00:08:43,755 Smiling is a movement, but it's evolved because of the way 132 00:08:43,755 --> 00:08:49,590 it-- the stimuli it that cause a reaction in others. 133 00:08:49,590 --> 00:08:51,750 OK? 134 00:08:51,750 --> 00:08:55,970 Almost all of us respond positively to smiles. 135 00:08:55,970 --> 00:08:57,150 OK? 136 00:08:57,150 --> 00:09:00,050 And we smile whether we're aware of it or not 137 00:09:00,050 --> 00:09:06,100 in order to, you know, get those positive responses. 138 00:09:06,100 --> 00:09:09,710 What other-- Can you think of anything else? 139 00:09:09,710 --> 00:09:12,760 Think of babies and their parents. 140 00:09:12,760 --> 00:09:17,804 They've evolved not just the larger head 141 00:09:17,804 --> 00:09:19,470 and the short limbs-- I mean there could 142 00:09:19,470 --> 00:09:21,178 be various reasons for that-- but they've 143 00:09:21,178 --> 00:09:23,120 evolved these chubby cheeks. 144 00:09:23,120 --> 00:09:25,260 They actually have fat pads in their cheeks 145 00:09:25,260 --> 00:09:28,690 that disappear later on. 146 00:09:28,690 --> 00:09:36,380 They've evolved specifically to elicit a certain reaction. 147 00:09:36,380 --> 00:09:39,560 And there's no doubt that human breasts have 148 00:09:39,560 --> 00:09:42,130 a similar function, that is breasts 149 00:09:42,130 --> 00:09:45,340 don't have to be as large as they are. 150 00:09:45,340 --> 00:09:50,264 They evolved in order to elicit response. 151 00:09:50,264 --> 00:09:51,260 OK? 152 00:09:51,260 --> 00:09:55,470 So these are what releaser are. 153 00:09:55,470 --> 00:09:58,100 And there's of course many others you can think of, 154 00:09:58,100 --> 00:10:01,090 various emotional expressions and things 155 00:10:01,090 --> 00:10:06,220 that also have evolved as these signals, social signals 156 00:10:06,220 --> 00:10:09,720 of various sorts. 157 00:10:09,720 --> 00:10:11,740 Now when we talk about mimicry, we're 158 00:10:11,740 --> 00:10:13,620 usually talking about something that's 159 00:10:13,620 --> 00:10:16,030 evolved to affect the behavior of another species. 160 00:10:16,030 --> 00:10:19,030 Like the monarch butterfly has mimics, 161 00:10:19,030 --> 00:10:24,200 because the monarch tastes terrible. 162 00:10:24,200 --> 00:10:27,770 Other, you know, birds won't generally attack monarchs, 163 00:10:27,770 --> 00:10:29,990 because they taste bad. 164 00:10:29,990 --> 00:10:33,030 So they quickly learn, you know? 165 00:10:33,030 --> 00:10:36,530 It only takes one experience of a really horrible taste 166 00:10:36,530 --> 00:10:39,720 and animals won't do it again. 167 00:10:39,720 --> 00:10:43,510 But so other butterflies and moths 168 00:10:43,510 --> 00:10:48,510 have evolved to mimic the bitter tasting ones, 169 00:10:48,510 --> 00:10:52,440 and the same thing happens in some insects. 170 00:10:52,440 --> 00:10:57,660 But in some cases a species evolves some way 171 00:10:57,660 --> 00:11:05,750 to mimic-- a mimic that affects its own species. 172 00:11:05,750 --> 00:11:09,250 And these are the two examples, I like the mouth breeder fish. 173 00:11:09,250 --> 00:11:10,710 Let's look at that here. 174 00:11:10,710 --> 00:11:11,950 The mouth breeder fish. 175 00:11:11,950 --> 00:11:13,130 Here's the male. 176 00:11:13,130 --> 00:11:20,430 And if you look here at the anal fin you see the little spots. 177 00:11:20,430 --> 00:11:22,680 What are those orange spots? 178 00:11:22,680 --> 00:11:26,790 Well they look just like the eggs of the female mouth 179 00:11:26,790 --> 00:11:28,040 breeder. 180 00:11:28,040 --> 00:11:29,650 Well what does the mouth breeder do? 181 00:11:29,650 --> 00:11:33,610 She lays her eggs and she takes them up in her mouth. 182 00:11:33,610 --> 00:11:36,510 She breeds them in her mouth. 183 00:11:36,510 --> 00:11:39,930 So she tries to get these, too. 184 00:11:39,930 --> 00:11:42,590 Perfect for the male. 185 00:11:42,590 --> 00:11:45,060 He comes after-- she comes after the male, 186 00:11:45,060 --> 00:11:48,050 her mouth is there trying to get at those eggs, 187 00:11:48,050 --> 00:11:49,940 and what does he do? 188 00:11:49,940 --> 00:11:54,150 He injects semen right into her mouth. 189 00:11:54,150 --> 00:11:57,190 So he fertilizes her eggs. 190 00:11:57,190 --> 00:12:00,415 So that's why the mouth breeder fish has evolved that way. 191 00:12:00,415 --> 00:12:01,690 The mouth breeder male. 192 00:12:01,690 --> 00:12:04,690 Now let's take baboons. 193 00:12:04,690 --> 00:12:09,425 Here's a female olive baboon, and notice this pink patch 194 00:12:09,425 --> 00:12:10,620 on her rump. 195 00:12:10,620 --> 00:12:13,130 It's used as a signal. 196 00:12:13,130 --> 00:12:15,590 It's evolved to affect the male. 197 00:12:15,590 --> 00:12:18,980 But then look, males evolve a patch, too. 198 00:12:18,980 --> 00:12:21,820 And some of them-- I couldn't find a really pink one, 199 00:12:21,820 --> 00:12:24,930 but this one's pink only at the edge. 200 00:12:24,930 --> 00:12:28,125 But the hamadryas baboon, it's even more obvious. 201 00:12:28,125 --> 00:12:30,500 You know here's a male hamadryas baboon, 202 00:12:30,500 --> 00:12:33,370 and look at the pink rump on that animal. 203 00:12:33,370 --> 00:12:37,020 And here are two females actually presenting to a male, 204 00:12:37,020 --> 00:12:38,800 and you can see. 205 00:12:38,800 --> 00:12:40,854 You know that's what's being imitated. 206 00:12:40,854 --> 00:12:42,020 Well why would they do that? 207 00:12:42,020 --> 00:12:45,560 Why would a male do that? 208 00:12:45,560 --> 00:12:50,120 Because if a female appears and presents to him 209 00:12:50,120 --> 00:12:54,280 it totally inhibits his aggressive response. 210 00:12:54,280 --> 00:12:56,081 These are pretty aggressive animals. 211 00:12:56,081 --> 00:12:56,580 OK? 212 00:12:56,580 --> 00:13:00,120 And they need ways to turn off the aggression, 213 00:13:00,120 --> 00:13:02,760 so the males have taken advantage of that. 214 00:13:02,760 --> 00:13:05,580 They evolve a signal where they can turn off 215 00:13:05,580 --> 00:13:08,610 the aggression of a more dominant male, 216 00:13:08,610 --> 00:13:11,630 and it protects them. 217 00:13:11,630 --> 00:13:14,090 And many rodents-- many of these things 218 00:13:14,090 --> 00:13:15,860 are a little more subtle. 219 00:13:15,860 --> 00:13:24,950 You know a hamster a normal Syrian hamster-- has evolved 220 00:13:24,950 --> 00:13:27,380 these white patches on his chest. 221 00:13:27,380 --> 00:13:27,880 OK? 222 00:13:27,880 --> 00:13:32,001 If those are exposed it reduces the aggression of a male. 223 00:13:32,001 --> 00:13:32,500 OK. 224 00:13:32,500 --> 00:13:34,500 If he wants to attack, he actually 225 00:13:34,500 --> 00:13:36,940 covers them with his feet. 226 00:13:36,940 --> 00:13:37,440 OK? 227 00:13:37,440 --> 00:13:39,950 Because of the signal property that they have, 228 00:13:39,950 --> 00:13:42,090 and similarly their white underbelly. 229 00:13:42,090 --> 00:13:45,640 If they expose that, because they're defeated in a fight, 230 00:13:45,640 --> 00:13:50,000 it generally works pretty well to inhibit the attack 231 00:13:50,000 --> 00:13:51,820 so they won't get killed. 232 00:13:51,820 --> 00:13:55,620 The only time I've had hamster males kill or females-- they 233 00:13:55,620 --> 00:13:57,840 both are pretty aggressive-- kill 234 00:13:57,840 --> 00:14:02,080 another animal is when it's an artificial situation 235 00:14:02,080 --> 00:14:04,190 in a cage where the animal gets caught 236 00:14:04,190 --> 00:14:08,750 and he can't expose the right stimuli. 237 00:14:08,750 --> 00:14:10,510 Like he's caught in the wire mesh 238 00:14:10,510 --> 00:14:16,000 or where he's not-- they're in such close quarters, 239 00:14:16,000 --> 00:14:20,310 he can't, you know, actually expose those signals. 240 00:14:20,310 --> 00:14:21,824 All right. 241 00:14:21,824 --> 00:14:23,490 Just a couple of other things, and we'll 242 00:14:23,490 --> 00:14:25,800 get onto the next class here. 243 00:14:25,800 --> 00:14:28,020 I want you to know what the dummy rule is. 244 00:14:28,020 --> 00:14:33,440 The rule is that if you can make a simple model-- 245 00:14:33,440 --> 00:14:37,530 like those models of the stickleback female-- that 246 00:14:37,530 --> 00:14:39,920 elicits a fixed action pattern-- like following 247 00:14:39,920 --> 00:14:42,130 response of the male-- then we're 248 00:14:42,130 --> 00:14:45,230 dealing with an innate releasing mechanism. 249 00:14:45,230 --> 00:14:48,650 Something that has-- on the sensory side-- 250 00:14:48,650 --> 00:14:51,850 that's evolved to respond to those stimuli. 251 00:14:51,850 --> 00:14:57,100 But if you can't find a dummy stimulus that works, 252 00:14:57,100 --> 00:15:00,770 it doesn't mean there's no innate releasing mechanism. 253 00:15:00,770 --> 00:15:05,070 And the reason is this, learning. 254 00:15:05,070 --> 00:15:10,550 The usual role of learning in animals, 255 00:15:10,550 --> 00:15:12,660 it does affect instinctive behavior. 256 00:15:12,660 --> 00:15:14,560 And the way it-- It usually doesn't 257 00:15:14,560 --> 00:15:16,550 affect the motor side very much. 258 00:15:16,550 --> 00:15:19,530 Different motor patterns can be linked in specific ways 259 00:15:19,530 --> 00:15:21,790 as we've talked about with the attack 260 00:15:21,790 --> 00:15:24,990 behavior, predatory attack in cats. 261 00:15:24,990 --> 00:15:28,450 They do have to put the various individual fix 262 00:15:28,450 --> 00:15:30,431 motor patterns together. 263 00:15:30,431 --> 00:15:30,930 OK? 264 00:15:30,930 --> 00:15:33,230 They learn that. 265 00:15:33,230 --> 00:15:35,640 But the selectivity of the stimuli 266 00:15:35,640 --> 00:15:38,450 that elicit the fixed action pattern 267 00:15:38,450 --> 00:15:40,680 can be increased with learning. 268 00:15:40,680 --> 00:15:41,180 OK? 269 00:15:41,180 --> 00:15:46,670 So in imprinting you see that happening. 270 00:15:46,670 --> 00:15:50,390 It can change with the experience of the animal. 271 00:15:50,390 --> 00:15:52,530 But even an animal that doesn't have to imprint, 272 00:15:52,530 --> 00:15:55,010 he responds innately to something. 273 00:15:55,010 --> 00:15:59,550 Like a novel box moved overhead above turkeys 274 00:15:59,550 --> 00:16:05,290 can elicit the anti-predatory response of crouching 275 00:16:05,290 --> 00:16:08,727 and freezing, but that can become more specific 276 00:16:08,727 --> 00:16:09,393 with experience. 277 00:16:16,770 --> 00:16:17,300 OK. 278 00:16:17,300 --> 00:16:20,460 Now this will take us the rest of this hour and Monday. 279 00:16:24,050 --> 00:16:27,860 I want to go through the theoretical models of fixed 280 00:16:27,860 --> 00:16:31,880 action patterns, and the innate releasing mechanisms 281 00:16:31,880 --> 00:16:37,580 of Lorenz and Tinbergen, which have been the major ones. 282 00:16:37,580 --> 00:16:40,240 And you can easily see how their models 283 00:16:40,240 --> 00:16:48,020 can be put into computer models using information flow. 284 00:16:48,020 --> 00:16:52,240 And that has been done fairly successfully. 285 00:16:52,240 --> 00:16:55,120 The second thing is the hierarchy and chains 286 00:16:55,120 --> 00:16:57,680 of behavior. 287 00:16:57,680 --> 00:17:02,510 The hierarchical organization of instinctive behavior. 288 00:17:02,510 --> 00:17:09,520 And then spatial orientation by reflexes, 289 00:17:09,520 --> 00:17:11,050 and an internal model. 290 00:17:11,050 --> 00:17:12,220 We'll talk about that. 291 00:17:12,220 --> 00:17:15,099 And then finally what happens when 292 00:17:15,099 --> 00:17:19,430 there are multiple motivations arise simultaneously? 293 00:17:19,430 --> 00:17:20,940 And that happens very commonly. 294 00:17:20,940 --> 00:17:26,829 And sometimes two motivations can be almost equally strong. 295 00:17:26,829 --> 00:17:30,490 How does an animal handle that? 296 00:17:30,490 --> 00:17:30,990 OK. 297 00:17:30,990 --> 00:17:36,890 So Lorenz' model we call-- it's sometimes 298 00:17:36,890 --> 00:17:38,950 been called a psycho-hydraulic model. 299 00:17:38,950 --> 00:17:42,500 It's really a sort of hydraulic mechanical model 300 00:17:42,500 --> 00:17:46,530 of the motivational state, the action 301 00:17:46,530 --> 00:17:49,210 specific potential in his terms. 302 00:17:49,210 --> 00:17:50,360 And he had two models. 303 00:17:50,360 --> 00:17:52,290 He changed it after awhile. 304 00:17:52,290 --> 00:17:55,840 On the left, there you see his old model. 305 00:17:55,840 --> 00:18:01,490 The action specific potential was represented as reservoir. 306 00:18:01,490 --> 00:18:06,780 The endogenous stimulus-- that is an internal stimulus-- 307 00:18:06,780 --> 00:18:09,630 is always there, and so it's gradually 308 00:18:09,630 --> 00:18:14,620 building up that level until its released. 309 00:18:14,620 --> 00:18:19,920 And he has the release there by the-- he 310 00:18:19,920 --> 00:18:23,160 throws this mechanical thing where the spring there 311 00:18:23,160 --> 00:18:26,300 represents some kind of inertia of the system. 312 00:18:26,300 --> 00:18:32,680 But the releasing stimuli there caused the discharge 313 00:18:32,680 --> 00:18:34,800 of that fluid. 314 00:18:34,800 --> 00:18:38,090 But then his observations on animals 315 00:18:38,090 --> 00:18:42,460 made him realize that it's not accurate enough, 316 00:18:42,460 --> 00:18:45,130 so he revised it. 317 00:18:45,130 --> 00:18:47,950 And he realized that there's not only 318 00:18:47,950 --> 00:18:55,850 this endogenous input that's gradually building up-- 319 00:18:55,850 --> 00:18:58,870 like our tendency to blink our eyes gradually 320 00:18:58,870 --> 00:19:00,130 builds up until we blink. 321 00:19:00,130 --> 00:19:02,739 And we do it spontaneously, and we don't even think about it. 322 00:19:02,739 --> 00:19:04,280 Unless right now I'm conscious of it, 323 00:19:04,280 --> 00:19:06,030 and I realized that I've now blinked twice 324 00:19:06,030 --> 00:19:08,110 since I started talking. 325 00:19:08,110 --> 00:19:08,610 OK. 326 00:19:08,610 --> 00:19:11,120 But he's got other stimuli there, too. 327 00:19:11,120 --> 00:19:16,190 And these are, he calls, readiness increasing stimuli. 328 00:19:16,190 --> 00:19:19,180 They are stimuli that don't act quite 329 00:19:19,180 --> 00:19:22,520 like the releasing-- they're not adequate to actually release 330 00:19:22,520 --> 00:19:26,370 the movement, but they do increase the motivation. 331 00:19:26,370 --> 00:19:28,430 OK? 332 00:19:28,430 --> 00:19:32,200 And you can think how many of those could be learned. 333 00:19:32,200 --> 00:19:36,760 But then the releasing stimulus-- 334 00:19:36,760 --> 00:19:44,250 the key stimuli that caused the discharge of the fixed motor 335 00:19:44,250 --> 00:19:48,810 pattern-- is like just pouring more fluid rapidly 336 00:19:48,810 --> 00:19:49,580 into the cup. 337 00:19:49,580 --> 00:19:53,350 So he sees the releasing stimuli as just something that 338 00:19:53,350 --> 00:19:57,625 raises the motivation to a high level, and it does so rapidly. 339 00:20:01,070 --> 00:20:05,020 And I've defined the various things there below. 340 00:20:05,020 --> 00:20:08,160 Now the major difference, of course, 341 00:20:08,160 --> 00:20:14,660 is the way the releasing stimuli are acting, as I pointed out. 342 00:20:14,660 --> 00:20:15,450 And the-- 343 00:20:18,490 --> 00:20:21,980 Where these things are in the CNS-- 344 00:20:21,980 --> 00:20:24,890 this is very far from any kind CNS model. 345 00:20:24,890 --> 00:20:26,540 It's an analogous model. 346 00:20:26,540 --> 00:20:27,040 OK? 347 00:20:30,270 --> 00:20:37,300 It's a hydraulic mechanical model that unfortunately looks 348 00:20:37,300 --> 00:20:39,910 more like a flush toilet than other things you can think of, 349 00:20:39,910 --> 00:20:46,270 and so sometimes Lorenz was made fun of for this. 350 00:20:46,270 --> 00:20:49,840 But in fact the model was useful in that it pointed out 351 00:20:49,840 --> 00:20:50,900 properties. 352 00:20:50,900 --> 00:20:53,400 He's basically summarizing properties 353 00:20:53,400 --> 00:20:55,980 that he observed for many different fixed action 354 00:20:55,980 --> 00:20:57,570 patterns. 355 00:20:57,570 --> 00:20:59,460 And the one on the right does a better job 356 00:20:59,460 --> 00:21:00,501 than the one on the left. 357 00:21:03,310 --> 00:21:06,280 Now if we talk about where these things are in the brain, 358 00:21:06,280 --> 00:21:07,650 it's interesting. 359 00:21:07,650 --> 00:21:13,020 Because if we go here-- Now let's say 360 00:21:13,020 --> 00:21:16,192 you're stimulating the spinal cord or the hindbrain. 361 00:21:16,192 --> 00:21:20,240 You can get various components of fixed motor patterns. 362 00:21:20,240 --> 00:21:21,860 OK? 363 00:21:21,860 --> 00:21:26,430 But generally only when the stimulus is on, you get them. 364 00:21:26,430 --> 00:21:31,980 So it's not acting at all like the action specific potential 365 00:21:31,980 --> 00:21:37,161 in the reservoir here where you get the whole sequence. 366 00:21:37,161 --> 00:21:37,660 OK? 367 00:21:40,690 --> 00:21:44,160 And when you suddenly take the stimulus away, 368 00:21:44,160 --> 00:21:48,000 the action doesn't just suddenly stop, just like in the model. 369 00:21:54,800 --> 00:21:57,240 So I just summarized that here. 370 00:21:57,240 --> 00:21:59,330 For low levels, the behavioral changes 371 00:21:59,330 --> 00:22:04,160 occur only during the periods of stimulation, then they stop. 372 00:22:04,160 --> 00:22:06,070 And in fact if you have an animal that's 373 00:22:06,070 --> 00:22:09,150 had a transection of the higher of the brain-- 374 00:22:09,150 --> 00:22:11,240 they've been totally separated. 375 00:22:11,240 --> 00:22:13,990 They're no longer influence-- the hypothalamic region, 376 00:22:13,990 --> 00:22:18,380 the whole forebrain is cut off from those lower regions-- 377 00:22:18,380 --> 00:22:20,660 you can still stimulate fixed action 378 00:22:20,660 --> 00:22:22,450 patterns, but only the motor component. 379 00:22:22,450 --> 00:22:24,450 And they just stop immediately, just 380 00:22:24,450 --> 00:22:27,160 like the effects of electrical stimulation of those lower 381 00:22:27,160 --> 00:22:29,920 levels. 382 00:22:29,920 --> 00:22:32,910 But when you stimulate in the caudal forebrain there, 383 00:22:32,910 --> 00:22:35,010 the hypothalamic area, then you do 384 00:22:35,010 --> 00:22:40,380 elicit moods that are very, very hard 385 00:22:40,380 --> 00:22:45,960 to distinguish from the mood that would occur normally. 386 00:22:49,190 --> 00:22:53,720 And that's been done for both the quiet, biting attack-- 387 00:22:53,720 --> 00:23:00,160 the predatory attack-- of a cat, and for the more aggressive 388 00:23:00,160 --> 00:23:01,510 defensive attack. 389 00:23:01,510 --> 00:23:03,100 And you are all familiar with that. 390 00:23:03,100 --> 00:23:08,000 The cat that arches its back, you know and extends its claws 391 00:23:08,000 --> 00:23:10,490 and makes a lot of noise. 392 00:23:10,490 --> 00:23:11,200 OK? 393 00:23:11,200 --> 00:23:13,890 We call the other one a quiet biting attack, 394 00:23:13,890 --> 00:23:16,680 because he does not make noise. 395 00:23:16,680 --> 00:23:20,090 It's designed specifically to kill prey. 396 00:23:24,980 --> 00:23:28,610 So I'm just pointing out I want you 397 00:23:28,610 --> 00:23:32,490 to give examples of the effects of the inertia of excitation 398 00:23:32,490 --> 00:23:33,335 in animal behavior. 399 00:23:36,960 --> 00:23:39,120 Think of an example from human behavior, 400 00:23:39,120 --> 00:23:41,760 but it occurs with animals, too. 401 00:23:41,760 --> 00:23:43,600 You suddenly remove the stimulus-- 402 00:23:43,600 --> 00:23:46,560 you elicit the whole-- you increase 403 00:23:46,560 --> 00:23:49,480 the level of motivation that-- remember 404 00:23:49,480 --> 00:23:52,200 Lorenz' model on the right there. 405 00:23:52,200 --> 00:23:57,140 You cause the motivation to go way, way up. 406 00:23:57,140 --> 00:24:00,580 If you just suddenly remove that stimulus, 407 00:24:00,580 --> 00:24:03,950 the behavior doesn't just go away. 408 00:24:03,950 --> 00:24:05,820 OK? 409 00:24:05,820 --> 00:24:09,590 I like the example from a Disney movie of a bear. 410 00:24:09,590 --> 00:24:13,880 They show the bear that's high on a hill, 411 00:24:13,880 --> 00:24:16,700 and he's trying to get something in a log-- a big log. 412 00:24:16,700 --> 00:24:19,585 And he crawls in to the log as far as he can get, 413 00:24:19,585 --> 00:24:21,250 and he gets stuck there. 414 00:24:21,250 --> 00:24:24,920 And then the log starts rolling downhill. 415 00:24:24,920 --> 00:24:29,690 Bonding downhill until finally it crashes against a tree 416 00:24:29,690 --> 00:24:31,340 and breaks open the log. 417 00:24:31,340 --> 00:24:35,770 And the bear comes out angry as can be. 418 00:24:35,770 --> 00:24:37,480 And he starts swatting. 419 00:24:37,480 --> 00:24:39,690 He pulls little trees. 420 00:24:39,690 --> 00:24:42,580 You know just like an angry human, 421 00:24:42,580 --> 00:24:45,270 that you don't get over it suddenly, 422 00:24:45,270 --> 00:24:46,970 even if the stimuli are gone. 423 00:24:50,162 --> 00:24:52,700 If something on the TV makes you very angry, 424 00:24:52,700 --> 00:24:54,905 some people have been known to break their TV. 425 00:24:58,360 --> 00:25:02,650 This is the inertia of excitation of a fixed action 426 00:25:02,650 --> 00:25:09,410 pattern by this change in the motivational level here 427 00:25:09,410 --> 00:25:11,160 on the right. 428 00:25:11,160 --> 00:25:14,100 You can remove that stimulus there, 429 00:25:14,100 --> 00:25:19,100 but the reservoir is so full that the action continues 430 00:25:19,100 --> 00:25:19,935 for some time. 431 00:25:23,150 --> 00:25:23,670 All right. 432 00:25:28,310 --> 00:25:30,680 So you see that with fear, with aggression, 433 00:25:30,680 --> 00:25:32,720 with sexual excitement, certainly. 434 00:25:32,720 --> 00:25:35,290 These are the areas certainly in human behavior, 435 00:25:35,290 --> 00:25:40,840 but also in many animals that you see that the most. 436 00:25:40,840 --> 00:25:44,880 How can we explain the fact that the urination activities 437 00:25:44,880 --> 00:25:48,390 of a male dog often don't depend on the amount of urine 438 00:25:48,390 --> 00:25:49,485 in the bladder? 439 00:25:49,485 --> 00:25:50,860 You say, well, why do we urinate? 440 00:25:50,860 --> 00:25:54,980 Well we have an urge to urinate, because the bladder's full. 441 00:25:54,980 --> 00:26:00,890 But in the case of a dog, urination has other functions. 442 00:26:00,890 --> 00:26:05,240 So there's two very different motivations that make, 443 00:26:05,240 --> 00:26:08,200 at least, the male dog urinate. 444 00:26:08,200 --> 00:26:12,570 In the case of female cats-- in the case of cats-- 445 00:26:12,570 --> 00:26:16,880 I don't know about-- I don't think dogs-- 446 00:26:16,880 --> 00:26:19,230 But what are they doing? 447 00:26:19,230 --> 00:26:20,560 Why do they hold back? 448 00:26:20,560 --> 00:26:24,810 They don't discharge all their urine. 449 00:26:24,810 --> 00:26:28,080 They need it for scent marking behavior, 450 00:26:28,080 --> 00:26:31,450 so that's a separate motivation. 451 00:26:31,450 --> 00:26:33,160 OK? 452 00:26:33,160 --> 00:26:38,440 And cats do it, too, both male and female, 453 00:26:38,440 --> 00:26:40,320 because of the odor. 454 00:26:40,320 --> 00:26:42,900 These are very olfactory animals, 455 00:26:42,900 --> 00:26:48,290 and their whole world is very different from ours. 456 00:26:48,290 --> 00:26:53,500 It is visual and auditory, like ours, but much more olfactory. 457 00:26:53,500 --> 00:26:57,350 They come into an area, they know 458 00:26:57,350 --> 00:27:00,340 which other cats, which individual cats 459 00:27:00,340 --> 00:27:02,500 have been in that region, and whether they 460 00:27:02,500 --> 00:27:04,060 were male or female. 461 00:27:04,060 --> 00:27:04,560 OK? 462 00:27:04,560 --> 00:27:05,670 And they leave their mark. 463 00:27:08,790 --> 00:27:10,350 Humans sometimes do that, too. 464 00:27:10,350 --> 00:27:13,415 They write on walls and things like that. 465 00:27:13,415 --> 00:27:13,915 OK. 466 00:27:21,230 --> 00:27:24,080 Let's talk about chains of behavior, 467 00:27:24,080 --> 00:27:28,770 and then the hierarchy of the systems of fixed action 468 00:27:28,770 --> 00:27:30,300 patterns. 469 00:27:30,300 --> 00:27:34,090 So as an example here I'm asking for a description 470 00:27:34,090 --> 00:27:36,400 of the chain of behavior patterns shown 471 00:27:36,400 --> 00:27:39,420 by newborn kittens in nursing behavior. 472 00:27:39,420 --> 00:27:40,420 It's very interesting. 473 00:27:40,420 --> 00:27:45,510 It's a consistent chain of behavior that they show. 474 00:27:45,510 --> 00:27:48,980 And normally one behavior leads to the next, 475 00:27:48,980 --> 00:27:51,840 because it leads to the stimulus that elicits the next. 476 00:27:51,840 --> 00:27:53,990 And I've listed them here. 477 00:27:53,990 --> 00:27:57,080 If he's awake, and he's not suckling, 478 00:27:57,080 --> 00:28:01,190 he shows this constant to and fro sideways sweeping movement 479 00:28:01,190 --> 00:28:07,770 of the head and foreparts of the body while he creeps forward. 480 00:28:07,770 --> 00:28:12,070 I know, of course, he's normally near the mother. 481 00:28:12,070 --> 00:28:14,830 And if he touches a solid vertical surface, 482 00:28:14,830 --> 00:28:17,810 even if it's not the mother, he snuggles up to it 483 00:28:17,810 --> 00:28:23,090 and maintains contact while he continues that sweeping motion. 484 00:28:23,090 --> 00:28:26,020 It's designed, of course-- even though it's a fixed motor 485 00:28:26,020 --> 00:28:32,500 pattern-- it's designed to find the teat of the mother. 486 00:28:32,500 --> 00:28:36,110 So if he contacts fur, he stops his forward motion. 487 00:28:36,110 --> 00:28:37,410 OK? 488 00:28:37,410 --> 00:28:39,200 But he continues the sweeping motions, 489 00:28:39,200 --> 00:28:40,835 his nose pressed against the fur. 490 00:28:40,835 --> 00:28:44,740 If he touches a bare spot, then he ceases the sweeping motion, 491 00:28:44,740 --> 00:28:47,290 and initiates a different behavior. 492 00:28:47,290 --> 00:28:49,050 He's kind of snapping. 493 00:28:49,050 --> 00:28:51,365 He's trying to get the teat in his mouth. 494 00:28:51,365 --> 00:28:54,830 So he finds it, he stops his other movements, 495 00:28:54,830 --> 00:28:57,970 and that initiates the suckling behavior. 496 00:28:57,970 --> 00:28:59,790 Sucking behavior. 497 00:28:59,790 --> 00:29:02,860 And also milk treading while he's sucking. 498 00:29:02,860 --> 00:29:04,915 You see this movement of the front paws. 499 00:29:09,600 --> 00:29:13,420 So each motor pattern serves as appetitive behaviour 500 00:29:13,420 --> 00:29:15,270 for the next fixed action pattern. 501 00:29:17,850 --> 00:29:22,990 Or I would say the next component of the sequence, 502 00:29:22,990 --> 00:29:24,495 because these are always linked. 503 00:29:27,310 --> 00:29:33,290 But Lorenz sees them as a very different fixed action 504 00:29:33,290 --> 00:29:38,770 patterns, because, in fact, you don't 505 00:29:38,770 --> 00:29:40,130 have to have the whole sequence. 506 00:29:40,130 --> 00:29:43,430 If you put the animal right next to the mother, 507 00:29:43,430 --> 00:29:45,330 the he won't show the earlier components. 508 00:29:45,330 --> 00:29:49,510 He does not have to go through the earlier ones, 509 00:29:49,510 --> 00:29:53,071 because they're all somewhat independent fixed action 510 00:29:53,071 --> 00:29:53,570 patterns. 511 00:29:53,570 --> 00:29:56,225 But they're normally linked because of the situation. 512 00:30:00,130 --> 00:30:03,280 And Tinbergen had described these kinds of things 513 00:30:03,280 --> 00:30:08,830 as examples of the hierarchical organization of instinct. 514 00:30:08,830 --> 00:30:12,030 And he has some very well known diagrams 515 00:30:12,030 --> 00:30:13,630 that you should be familiar with. 516 00:30:16,620 --> 00:30:19,720 He shows a view of innate releasing mechanisms 517 00:30:19,720 --> 00:30:22,970 that are quite a bit different from Lorenz. 518 00:30:22,970 --> 00:30:25,190 They did work together some, but they 519 00:30:25,190 --> 00:30:28,350 had a different way of picturing it. 520 00:30:28,350 --> 00:30:31,330 And you can see that he doesn't explain some of the aspects 521 00:30:31,330 --> 00:30:32,750 that Lorenz was dealing with. 522 00:30:32,750 --> 00:30:35,940 All that stuff about the inertia behavior and so forth, 523 00:30:35,940 --> 00:30:37,950 he didn't try to deal with. 524 00:30:37,950 --> 00:30:40,070 But he did deal with the hierarchy. 525 00:30:40,070 --> 00:30:43,205 In this case we just take one component of it. 526 00:30:43,205 --> 00:30:43,705 OK? 527 00:30:48,860 --> 00:30:55,550 And this is just for example. 528 00:30:55,550 --> 00:30:59,560 We're dealing with an aspect of reproductive behavior. 529 00:30:59,560 --> 00:31:01,485 Hormones provide a major input. 530 00:31:04,890 --> 00:31:09,340 The higher level could be coming from the visual system that 531 00:31:09,340 --> 00:31:10,740 signals the time of year. 532 00:31:14,070 --> 00:31:17,440 Other input that increase that motivation. 533 00:31:17,440 --> 00:31:22,740 And then, unlike Lorenz, he has a block 534 00:31:22,740 --> 00:31:26,520 preventing the continuous discharge of the motor 535 00:31:26,520 --> 00:31:28,150 patterns. 536 00:31:28,150 --> 00:31:32,710 And the innate releasing mechanism-- 537 00:31:32,710 --> 00:31:35,580 and then the stimulus that activates the innate releasing 538 00:31:35,580 --> 00:31:39,550 mechanism-- its function is simply to remove that block. 539 00:31:39,550 --> 00:31:42,610 And then the block, once it's removed, 540 00:31:42,610 --> 00:31:46,040 can elicit a whole series. 541 00:31:46,040 --> 00:31:47,586 And which one would be first? 542 00:31:47,586 --> 00:31:49,210 Well the one with the lowest threshold, 543 00:31:49,210 --> 00:31:52,251 and normally that's appetitive behavior. 544 00:31:52,251 --> 00:31:52,750 OK. 545 00:31:52,750 --> 00:31:56,900 And these different components of the fixed action pattern 546 00:31:56,900 --> 00:31:59,190 are normally inhibiting each other. 547 00:31:59,190 --> 00:32:02,260 And this shows a more complete model 548 00:32:02,260 --> 00:32:05,650 where he shows a male stickleback 549 00:32:05,650 --> 00:32:07,350 reproductive behavior. 550 00:32:07,350 --> 00:32:09,520 Basically the whole hierarchy starting 551 00:32:09,520 --> 00:32:13,310 with hormones with the spring migration. 552 00:32:13,310 --> 00:32:17,130 The nature of the water has an influence, 553 00:32:17,130 --> 00:32:20,370 the plants in the vicinity, and various internal factors. 554 00:32:20,370 --> 00:32:22,060 And then there's the block. 555 00:32:22,060 --> 00:32:24,950 The innate releasing mechanisms that can remove the block 556 00:32:24,950 --> 00:32:27,810 and start these various behaviors. 557 00:32:27,810 --> 00:32:30,500 And note he has the mutual inhibition shown 558 00:32:30,500 --> 00:32:33,090 by the double arrows here. 559 00:32:33,090 --> 00:32:36,170 He has fighting, nesting, courtship, 560 00:32:36,170 --> 00:32:40,320 and parental behavior, each with somewhat different stimuli. 561 00:32:40,320 --> 00:32:43,020 And so depending on the stimuli there, 562 00:32:43,020 --> 00:32:45,820 these will be discharged. 563 00:32:45,820 --> 00:32:49,060 And then he shows the lower levels, too. 564 00:32:49,060 --> 00:32:51,050 The level of the actual action. 565 00:32:51,050 --> 00:32:54,095 So here for fighting behavior he has the displaying, the biting, 566 00:32:54,095 --> 00:32:55,750 and the chasing. 567 00:32:55,750 --> 00:32:56,250 OK? 568 00:32:56,250 --> 00:32:59,920 And if you get the display purring, 569 00:32:59,920 --> 00:33:03,180 then you get whole fins, raise of one 570 00:33:03,180 --> 00:33:08,850 fin, muscle fibers of one ray, and motor neurons. 571 00:33:08,850 --> 00:33:11,430 For when the muscle fiber-- 572 00:33:11,430 --> 00:33:13,470 So he shows the whole hierarchy here. 573 00:33:13,470 --> 00:33:17,010 And this is often reproduced, because-- Neuroscientists 574 00:33:17,010 --> 00:33:21,590 like it because it sort of fits the hierarchical organization 575 00:33:21,590 --> 00:33:23,440 of the nervous system. 576 00:33:23,440 --> 00:33:26,230 And this shows a functional picture of that. 577 00:33:29,160 --> 00:33:29,660 OK. 578 00:33:29,660 --> 00:33:30,160 And I'm-- 579 00:33:32,780 --> 00:33:34,920 This is the level of ethology up here, 580 00:33:34,920 --> 00:33:36,755 and you are at the level of neurophysiology. 581 00:33:36,755 --> 00:33:39,710 They study different aspects of it. 582 00:33:39,710 --> 00:33:43,000 But in fact the physiologist working on hypothalamus 583 00:33:43,000 --> 00:33:46,360 have also studied many of these things. 584 00:33:50,590 --> 00:33:53,760 So the major difference then between the Lorenz model 585 00:33:53,760 --> 00:33:58,560 and the Tinbergen model I've listed for you here. 586 00:33:58,560 --> 00:34:01,200 Obviously Tinbergen's view was the broader one. 587 00:34:04,340 --> 00:34:08,020 It looks more like an information flow scheme. 588 00:34:08,020 --> 00:34:12,790 But Lorenz by focusing on the dynamics of the drive 589 00:34:12,790 --> 00:34:15,340 state, the action specific potential, and the innate 590 00:34:15,340 --> 00:34:23,000 releasing mechanism it's showing very different aspects 591 00:34:23,000 --> 00:34:27,310 of the properties of innate behavior. 592 00:34:27,310 --> 00:34:29,665 And here I just point out the strengths and weaknesses. 593 00:34:34,080 --> 00:34:36,889 And I also note that Tinbergen's model 594 00:34:36,889 --> 00:34:40,260 has been more popular among the neural people. 595 00:34:43,130 --> 00:34:46,719 But it was the Lorenz view that was actually 596 00:34:46,719 --> 00:34:50,235 used in the modeling of real behavior patterns in animals. 597 00:34:53,600 --> 00:34:57,340 In the work of Bruce Blumberg here at MIT when 598 00:34:57,340 --> 00:34:59,660 he was doing that in the media lab. 599 00:34:59,660 --> 00:35:00,160 OK. 600 00:35:04,580 --> 00:35:10,790 So let's go to the discussion of Lorenz-- of the work 601 00:35:10,790 --> 00:35:11,590 of [INAUDIBLE]. 602 00:35:11,590 --> 00:35:14,640 And this is his work on the female digger wasp, 603 00:35:14,640 --> 00:35:17,620 because it points out another aspect of innate behavior 604 00:35:17,620 --> 00:35:19,740 that I think is quite important. 605 00:35:19,740 --> 00:35:23,740 And this-- We're going to come back to the digger wasp 606 00:35:23,740 --> 00:35:29,030 next week when we read a little bit from Tinbergen 607 00:35:29,030 --> 00:35:35,140 and his studies of orienting behavior in that wasp. 608 00:35:35,140 --> 00:35:38,760 How does he find things? 609 00:35:38,760 --> 00:35:39,260 OK. 610 00:35:39,260 --> 00:35:48,160 So he's doing experiments on the influence of inspections 611 00:35:48,160 --> 00:35:51,000 of the nest by the wasp. 612 00:35:51,000 --> 00:35:54,470 It's a behavior that has a lot of plasticity. 613 00:35:54,470 --> 00:35:55,900 OK? 614 00:35:55,900 --> 00:36:01,366 And this is what the digger wasp is like. 615 00:36:01,366 --> 00:36:03,690 And note there's a hole in the sand. 616 00:36:03,690 --> 00:36:07,700 And she's made that hole, and it's basically a nest. 617 00:36:07,700 --> 00:36:12,890 She makes nests in the sand, little holes in the sand. 618 00:36:12,890 --> 00:36:17,030 And she digs a separate hole for every egg she lays. 619 00:36:20,640 --> 00:36:24,540 And she has to-- 620 00:36:24,540 --> 00:36:26,420 The egg will hatch. 621 00:36:26,420 --> 00:36:28,030 A larvae comes out. 622 00:36:28,030 --> 00:36:29,770 And when the larvae comes out, they 623 00:36:29,770 --> 00:36:32,040 have to have food right away. 624 00:36:32,040 --> 00:36:36,890 So she catches insects. 625 00:36:36,890 --> 00:36:40,550 This wasp is catching little insects and worms. 626 00:36:40,550 --> 00:36:44,570 And brings them-- killing them and bringing them, 627 00:36:44,570 --> 00:36:47,390 putting them in these nests. 628 00:36:47,390 --> 00:36:49,080 But she doesn't have just one nest. 629 00:36:49,080 --> 00:36:51,390 She has a bunch of them. 630 00:36:51,390 --> 00:36:55,830 And so when she comes to a nest she 631 00:36:55,830 --> 00:37:00,460 inspects-- Her first task is just to inspect it. 632 00:37:00,460 --> 00:37:06,840 And if it's already got some food there, then she goes on. 633 00:37:06,840 --> 00:37:13,710 And if it's empty, then she will fly off, 634 00:37:13,710 --> 00:37:15,040 and she will bring food back. 635 00:37:15,040 --> 00:37:18,620 And she has to remember which nest it was, and she does. 636 00:37:18,620 --> 00:37:21,390 She does it pretty accurately. 637 00:37:21,390 --> 00:37:23,120 OK? 638 00:37:23,120 --> 00:37:25,350 And she can have a lot of different nests. 639 00:37:25,350 --> 00:37:27,445 So when you look at the whole situation 640 00:37:27,445 --> 00:37:29,930 it seems like quite complex behavior 641 00:37:29,930 --> 00:37:32,150 that obviously involves some learning. 642 00:37:32,150 --> 00:37:36,750 And yet the whole structure is innate behavior, 643 00:37:36,750 --> 00:37:38,760 but with these specific things she 644 00:37:38,760 --> 00:37:41,935 has to remember in order to carry out the whole sequence. 645 00:37:46,470 --> 00:37:49,950 So what she detects in a nest determines her next behavior. 646 00:37:49,950 --> 00:37:52,710 Looks like my words didn't all copy there. 647 00:37:55,220 --> 00:37:59,140 So the behavior sequences are complicated by the fact 648 00:37:59,140 --> 00:38:00,890 that she digs and uses multiple nests. 649 00:38:06,360 --> 00:38:11,460 And that led in general motivational states underlying 650 00:38:11,460 --> 00:38:14,110 the feeding behavior of chicks and geese 651 00:38:14,110 --> 00:38:19,190 also show this relative hierarchy of moods. 652 00:38:19,190 --> 00:38:22,360 And a good example is the feeding 653 00:38:22,360 --> 00:38:25,550 of ducks, which we talked about that a little bit. 654 00:38:25,550 --> 00:38:28,415 But we didn't describe this behavior, the upending behavior 655 00:38:28,415 --> 00:38:29,540 of ducks and geese. 656 00:38:29,540 --> 00:38:31,650 What's upending? 657 00:38:31,650 --> 00:38:35,830 Have you ever watched ducks or geese feeding in a pond? 658 00:38:35,830 --> 00:38:39,130 Much of the time you only see their tail. 659 00:38:39,130 --> 00:38:41,080 They're upended. 660 00:38:41,080 --> 00:38:43,880 They're looking for something down below. 661 00:38:43,880 --> 00:38:44,800 OK? 662 00:38:44,800 --> 00:38:47,970 And that's how they feed. 663 00:38:47,970 --> 00:38:54,601 If you feed the geese, or the ducks, on the ground then 664 00:38:54,601 --> 00:38:55,850 they wouldn't have to do that. 665 00:38:55,850 --> 00:38:56,656 Right? 666 00:38:56,656 --> 00:39:00,850 Ah, but they're highly motivated to do upending. 667 00:39:00,850 --> 00:39:03,700 See it's a separate motivation. 668 00:39:03,700 --> 00:39:08,940 So if you deprive them of food, they will go out and upend. 669 00:39:08,940 --> 00:39:10,302 OK? 670 00:39:10,302 --> 00:39:15,130 They're not-- They're feeding because they want to upend. 671 00:39:15,130 --> 00:39:17,410 They're not upending in order to feed. 672 00:39:17,410 --> 00:39:19,650 And that's similar to what we talked about 673 00:39:19,650 --> 00:39:24,110 before when we talked about the starling poking into things. 674 00:39:24,110 --> 00:39:26,420 He's so highly motivated to poke, 675 00:39:26,420 --> 00:39:28,460 that even if he's well fed, he will do it. 676 00:39:28,460 --> 00:39:32,320 And similarly the cactus finch would still find a cactus spine 677 00:39:32,320 --> 00:39:33,806 and poke into things. 678 00:39:33,806 --> 00:39:36,180 Because he's highly-- even if he's well fed, because he's 679 00:39:36,180 --> 00:39:37,530 highly motivated to do that. 680 00:39:40,700 --> 00:39:48,420 So well fed birds deprived of upending-- we'll do that. 681 00:39:48,420 --> 00:39:52,500 Here's the picture of what it looks like. 682 00:39:52,500 --> 00:39:53,390 Two ducks upending. 683 00:39:59,540 --> 00:40:02,730 And I just point out here that the action specific potential 684 00:40:02,730 --> 00:40:06,127 for that behavior is separate than for hunger. 685 00:40:08,750 --> 00:40:11,675 So to deprive them of it, they will show the behavior. 686 00:40:15,370 --> 00:40:17,590 Lorenz has this interesting little discussion 687 00:40:17,590 --> 00:40:21,860 of why the head-- which he says contains 688 00:40:21,860 --> 00:40:24,350 the locus of superior command-- had 689 00:40:24,350 --> 00:40:28,320 to be invented in evolution. 690 00:40:28,320 --> 00:40:33,680 So how is the function-- I'm asking, 691 00:40:33,680 --> 00:40:35,360 has the function of the head ganglion 692 00:40:35,360 --> 00:40:37,395 changed in higher vertebrates with respect 693 00:40:37,395 --> 00:40:40,140 to fixed action patterns? 694 00:40:40,140 --> 00:40:41,810 And that's an interesting question. 695 00:40:41,810 --> 00:40:45,390 Lorenz says the head had to evolve to limit behavior 696 00:40:45,390 --> 00:40:46,785 to one motor pattern at a time. 697 00:40:52,710 --> 00:40:56,020 It was to embody the innate releasing mechanisms also, 698 00:40:56,020 --> 00:40:58,650 because most innate releasing mechanisms involve 699 00:40:58,650 --> 00:41:00,750 stimuli coming into the head. 700 00:41:00,750 --> 00:41:04,680 And the stimuli come in through the cranial nerves. 701 00:41:04,680 --> 00:41:08,040 Most of them do not come in through the spinal nerves. 702 00:41:08,040 --> 00:41:10,450 OK? 703 00:41:10,450 --> 00:41:14,560 There are some components, for example in that nursing 704 00:41:14,560 --> 00:41:18,750 behavior of the kitten looking for the opportunity 705 00:41:18,750 --> 00:41:21,855 to nurse that do come in through the spinal cord. 706 00:41:21,855 --> 00:41:23,855 But most of them are coming in through the head. 707 00:41:27,950 --> 00:41:29,530 And I'm asking here how the function 708 00:41:29,530 --> 00:41:32,000 has changed in higher vertebrates? 709 00:41:32,000 --> 00:41:35,950 I would say that the main thing that's been changing 710 00:41:35,950 --> 00:41:38,410 is increased linkage between innate 711 00:41:38,410 --> 00:41:39,890 and learned aspects of behavior. 712 00:41:39,890 --> 00:41:43,410 And that reaches a peak in humans, 713 00:41:43,410 --> 00:41:47,360 but it's very prominent in other animals. 714 00:41:47,360 --> 00:41:51,800 And the other is initiation of behavior patterns 715 00:41:51,800 --> 00:41:54,210 by learned motivations. 716 00:41:54,210 --> 00:41:56,674 Motivations can be learned. 717 00:41:56,674 --> 00:41:57,500 OK? 718 00:41:57,500 --> 00:42:01,220 And acquired motivations are common. 719 00:42:01,220 --> 00:42:03,120 We all know about, of course, some 720 00:42:03,120 --> 00:42:06,920 of the bad ones, the addictive behaviors. 721 00:42:06,920 --> 00:42:08,710 But there are many different motivations. 722 00:42:08,710 --> 00:42:12,290 We become highly motivated to do certain tasks. 723 00:42:12,290 --> 00:42:12,790 OK? 724 00:42:12,790 --> 00:42:17,520 Well that was not-- we didn't carry that with us 725 00:42:17,520 --> 00:42:19,030 from the uterus. 726 00:42:19,030 --> 00:42:19,530 OK? 727 00:42:23,820 --> 00:42:30,300 But also our cognitive level, we contain a model of the world. 728 00:42:30,300 --> 00:42:34,750 And in that we make-- embodies choices we make and so forth. 729 00:42:41,240 --> 00:42:43,660 I just point out here that the cognitive level 730 00:42:43,660 --> 00:42:47,430 is at the top of a neural hierarchy. 731 00:42:47,430 --> 00:42:50,400 But it doesn't mean just because it's at the top 732 00:42:50,400 --> 00:42:52,290 that it's always dominant. 733 00:42:52,290 --> 00:42:54,460 And we all know that for sure. 734 00:42:54,460 --> 00:42:58,510 People can be totally dominated by the drive 735 00:42:58,510 --> 00:43:06,590 to enact revenge, drive to feed, drive to acquire things. 736 00:43:06,590 --> 00:43:08,940 These are innate behavior patterns. 737 00:43:08,940 --> 00:43:17,110 And that cognitive level that's often not at the top. 738 00:43:17,110 --> 00:43:21,500 Maybe in true intellectuals it is. 739 00:43:21,500 --> 00:43:25,935 I define a true intellectual as somebody who, by what he knows 740 00:43:25,935 --> 00:43:29,380 and what he learns-- the cognitions 741 00:43:29,380 --> 00:43:31,400 that he acquires-- actually affect 742 00:43:31,400 --> 00:43:34,230 his behavior in a major way. 743 00:43:34,230 --> 00:43:37,400 It's not true of most people. 744 00:43:37,400 --> 00:43:42,360 In fact when one student working with Bruce and with me 745 00:43:42,360 --> 00:43:46,490 here at MIT was simulating human behavior, 746 00:43:46,490 --> 00:43:50,850 everything in it, except for some very simple spatial 747 00:43:50,850 --> 00:43:53,180 things, was not learned. 748 00:43:53,180 --> 00:43:56,190 It was all built into the software. 749 00:43:56,190 --> 00:44:01,480 And yet you show the results of simulations 750 00:44:01,480 --> 00:44:04,080 where you see people moving around, making choices, 751 00:44:04,080 --> 00:44:07,175 and this and that, it looks like pretty normal human behavior. 752 00:44:09,800 --> 00:44:12,330 So a lot of times when we're observing human behavior, 753 00:44:12,330 --> 00:44:14,340 we're just looking at fixed action patterns. 754 00:44:18,110 --> 00:44:18,610 All right. 755 00:44:22,160 --> 00:44:26,445 Next topic here concerns what we call taxis and reflexes. 756 00:44:26,445 --> 00:44:29,330 This involves spatial orientation. 757 00:44:29,330 --> 00:44:32,825 And that leads to a discussion of thinking in higher animals. 758 00:44:35,400 --> 00:44:37,720 First of all-- and we won't have time 759 00:44:37,720 --> 00:44:41,190 for too much more than this-- explain 760 00:44:41,190 --> 00:44:44,020 how the mantle of reflexes-- the term I've 761 00:44:44,020 --> 00:44:50,010 used from Fromholtz and Lorenz uses it, I believe. 762 00:44:52,540 --> 00:44:56,718 It tends to conceal the rigidity of fixed motor patterns. 763 00:44:56,718 --> 00:44:57,990 You know? 764 00:44:57,990 --> 00:45:00,760 When we walk, for example, we know 765 00:45:00,760 --> 00:45:02,300 that's a fixed motor pattern. 766 00:45:02,300 --> 00:45:05,250 It appears at a certain age when the neural mechanisms 767 00:45:05,250 --> 00:45:07,350 of the spinal cord mature. 768 00:45:07,350 --> 00:45:10,240 And the various gaits are walking and running. 769 00:45:10,240 --> 00:45:13,250 The various gaits of a horse, which are multiple. 770 00:45:13,250 --> 00:45:15,050 They're all inherited. 771 00:45:15,050 --> 00:45:18,280 And yet at least, especially for humans, 772 00:45:18,280 --> 00:45:22,840 when we're walking around it seems to vary a lot. 773 00:45:22,840 --> 00:45:25,315 It depends on what we're walking on. 774 00:45:25,315 --> 00:45:26,970 It depends on the terrain. 775 00:45:26,970 --> 00:45:29,350 Even horses change the way they walk, 776 00:45:29,350 --> 00:45:31,890 even though-- much less than, say, the more sure 777 00:45:31,890 --> 00:45:35,470 footed animals like goats and donkeys. 778 00:45:35,470 --> 00:45:40,210 But it's being adjusted by the reflexes. 779 00:45:40,210 --> 00:45:41,420 You know? 780 00:45:41,420 --> 00:45:45,810 If I'm walking along here, I'm responding visually here, too. 781 00:45:45,810 --> 00:45:47,350 And I don't even look here, but I 782 00:45:47,350 --> 00:45:48,860 can see the edge of this table. 783 00:45:48,860 --> 00:45:51,710 And I will walk around it without even thinking about it. 784 00:45:51,710 --> 00:45:58,550 This is just an example of simple spatial orientation 785 00:45:58,550 --> 00:46:03,000 reflexes that alter the way the locomotion is expressed. 786 00:46:03,000 --> 00:46:06,040 And there's much simpler examples. 787 00:46:06,040 --> 00:46:08,840 Like the egg rolling behavior of the graylag goose. 788 00:46:08,840 --> 00:46:12,300 Every time you see a graylag goose rolling an egg back 789 00:46:12,300 --> 00:46:14,830 into the nest, it looks a little different 790 00:46:14,830 --> 00:46:16,400 than other times you see it. 791 00:46:16,400 --> 00:46:19,620 Because the egg is rolling this way and that. 792 00:46:19,620 --> 00:46:22,060 It's meeting little stones and he 793 00:46:22,060 --> 00:46:27,045 has to keep adjusting how he's getting his beak over the egg 794 00:46:27,045 --> 00:46:29,300 and pulling it back towards the nest. 795 00:46:29,300 --> 00:46:31,235 So it looks like it's complex, and yet it's 796 00:46:31,235 --> 00:46:32,550 a fixed motor pattern. 797 00:46:32,550 --> 00:46:34,950 That's basically the same motor pattern, 798 00:46:34,950 --> 00:46:39,435 but it's working at a higher level than all these reflexes 799 00:46:39,435 --> 00:46:41,440 that are constantly adjusting it. 800 00:46:41,440 --> 00:46:43,590 And the reflexes never stop. 801 00:46:43,590 --> 00:46:46,730 Remember they don't depend on the motivation. 802 00:46:46,730 --> 00:46:47,560 They always act. 803 00:46:50,310 --> 00:46:52,160 So it looks variable and complex, 804 00:46:52,160 --> 00:46:58,730 because it's superimposed on the behavior 805 00:46:58,730 --> 00:47:00,100 of these various reflexes. 806 00:47:00,100 --> 00:47:01,030 They're vestibular. 807 00:47:01,030 --> 00:47:02,360 They're tactile. 808 00:47:02,360 --> 00:47:06,000 They're visual, and so forth. 809 00:47:09,320 --> 00:47:11,220 Last topic. 810 00:47:11,220 --> 00:47:15,640 A goldfish behind a barrier. 811 00:47:15,640 --> 00:47:19,140 Let's say these are thick weeds. 812 00:47:19,140 --> 00:47:22,370 He can't swim through, but he can see through it 813 00:47:22,370 --> 00:47:24,755 well enough to see that there's food on the other side. 814 00:47:28,940 --> 00:47:30,520 How does he solve that problem? 815 00:47:30,520 --> 00:47:33,670 And actually goldfish do pretty well. 816 00:47:33,670 --> 00:47:37,220 Better than dogs actually. 817 00:47:37,220 --> 00:47:38,690 Here's what he does. 818 00:47:38,690 --> 00:47:41,740 He swims right for it. 819 00:47:41,740 --> 00:47:46,970 And as soon as he touches it, he's got another reflex. 820 00:47:46,970 --> 00:47:47,470 OK? 821 00:47:47,470 --> 00:47:50,080 We call it a negative thigmotaxis. 822 00:47:50,080 --> 00:47:54,030 A negative response to touching with his snot, and that 823 00:47:54,030 --> 00:47:56,020 causes him to pull back. 824 00:47:56,020 --> 00:47:58,690 Now of course the algorithm can vary among fish, 825 00:47:58,690 --> 00:48:00,420 and it's very different in dogs. 826 00:48:00,420 --> 00:48:02,890 But normally he will keep trying to get at the food, 827 00:48:02,890 --> 00:48:05,510 but he will keep moving like this 828 00:48:05,510 --> 00:48:09,180 until he can get at the food. 829 00:48:09,180 --> 00:48:11,940 So just two reflexes are enough. 830 00:48:11,940 --> 00:48:15,850 Positive telotaxis is what we call his moving 831 00:48:15,850 --> 00:48:17,320 towards the food. 832 00:48:17,320 --> 00:48:20,000 It's just a technical name for it, positive telotaxis. 833 00:48:20,000 --> 00:48:23,860 Telo means the end, taxis movement. 834 00:48:23,860 --> 00:48:24,560 OK? 835 00:48:24,560 --> 00:48:28,652 Directed towards the prey, or towards the other food 836 00:48:28,652 --> 00:48:29,860 that he was trying to get to. 837 00:48:29,860 --> 00:48:33,140 And then the negative thigmotaxis 838 00:48:33,140 --> 00:48:37,740 causes him to avoid the obstacles, branches, plants, 839 00:48:37,740 --> 00:48:39,110 so forth. 840 00:48:39,110 --> 00:48:40,735 So it looks like intelligent behavior. 841 00:48:43,590 --> 00:48:46,510 He seems to figure out how to reach the food, 842 00:48:46,510 --> 00:48:50,480 but in fact it's just two reflexes running on. 843 00:48:50,480 --> 00:48:51,530 OK? 844 00:48:51,530 --> 00:48:53,845 So now think about how a dog does it. 845 00:48:53,845 --> 00:48:57,390 And we'll come back here next time.