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 00:00:21,540 --> 00:00:23,040 PROFESSOR: What are tool activities, 9 00:00:23,040 --> 00:00:25,560 and why does Lorenz call them tool activities? 10 00:00:30,540 --> 00:00:34,060 This should be an easy question if you're doing any reading. 11 00:00:40,550 --> 00:00:42,324 What does he mean by tool activities? 12 00:00:46,280 --> 00:00:50,000 I know some of you know. 13 00:00:50,000 --> 00:00:51,000 Do you know? 14 00:00:51,000 --> 00:00:54,240 You don't remember? 15 00:00:54,240 --> 00:00:58,630 I guess you were doing homework instead of reading. 16 00:00:58,630 --> 00:01:02,050 All right, tool activities mean multi-purpose actions. 17 00:01:02,050 --> 00:01:06,770 They're instinctive action patterns. 18 00:01:06,770 --> 00:01:08,500 They do have a motivational component, 19 00:01:08,500 --> 00:01:12,980 so they're classified as fixed action patterns, rather than 20 00:01:12,980 --> 00:01:14,050 reflexes. 21 00:01:14,050 --> 00:01:19,280 But they refer to multi-purpose actions that the very same-- 22 00:01:19,280 --> 00:01:22,150 they're components of many different fixed action 23 00:01:22,150 --> 00:01:24,354 patterns. 24 00:01:24,354 --> 00:01:26,520 But they're also fixed action patterns of their own. 25 00:01:26,520 --> 00:01:28,182 Like locomotion. 26 00:01:28,182 --> 00:01:33,520 You know, we use locomotion as part of the appetitive behavior 27 00:01:33,520 --> 00:01:39,370 behind any-- very many other fixed action patterns. 28 00:01:39,370 --> 00:01:44,200 And the same is true of orienting movements. 29 00:01:48,980 --> 00:01:55,710 We make orienting movements in response to stimuli, it's true. 30 00:01:55,710 --> 00:01:58,030 And that makes them seem like reflexes. 31 00:01:58,030 --> 00:02:01,080 But in fact, they're part of many fixed action patterns. 32 00:02:04,360 --> 00:02:08,889 And we don't just sit without even stimuli. 33 00:02:08,889 --> 00:02:10,699 You know, even if none of you were moving, 34 00:02:10,699 --> 00:02:13,760 I don't just stare at one place. 35 00:02:13,760 --> 00:02:15,950 My eyes are always roaming around. 36 00:02:15,950 --> 00:02:18,610 I'm making orienting movements. 37 00:02:18,610 --> 00:02:21,900 Grasping with the hands is the same. 38 00:02:21,900 --> 00:02:27,860 So each of these major types of activities are tool activities, 39 00:02:27,860 --> 00:02:31,850 and there's actually many varieties of each one. 40 00:02:31,850 --> 00:02:34,810 For locomotion, is easiest talk about there, 41 00:02:34,810 --> 00:02:39,200 because we defined the various gates, especially 42 00:02:39,200 --> 00:02:40,850 in four-legged animals. 43 00:02:40,850 --> 00:02:45,237 But humans still have various types of walking and running, 44 00:02:45,237 --> 00:02:46,320 various speeds of running. 45 00:02:48,960 --> 00:02:53,130 OK now what about the action-specific potential 46 00:02:53,130 --> 00:02:57,035 behind these and other fixed action patterns. 47 00:03:00,940 --> 00:03:06,800 We know that, if they're like most fixed action patterns, 48 00:03:06,800 --> 00:03:10,650 the action specific potential, meaning 49 00:03:10,650 --> 00:03:13,590 the level of motivation, builds up over time. 50 00:03:13,590 --> 00:03:18,140 Well it doesn't build up at the same rate for different fixed 51 00:03:18,140 --> 00:03:19,122 action patterns. 52 00:03:22,070 --> 00:03:24,100 It tends to build up at a rate proportional 53 00:03:24,100 --> 00:03:28,340 to how often the movement is needed. 54 00:03:40,180 --> 00:03:42,800 And we know that many of these fixed action patterns, 55 00:03:42,800 --> 00:03:46,680 like predatory behavior in the cat, 56 00:03:46,680 --> 00:03:53,230 are actually inherited as a series of different fixed 57 00:03:53,230 --> 00:03:54,680 action patterns. 58 00:03:54,680 --> 00:03:56,620 But they become linked during development. 59 00:03:59,590 --> 00:04:03,710 That is, habits form depending on the experience 60 00:04:03,710 --> 00:04:05,950 of the animal, usually with the mother, 61 00:04:05,950 --> 00:04:12,730 in the case of predatory cats, and the various patterns 62 00:04:12,730 --> 00:04:15,540 become linked. 63 00:04:15,540 --> 00:04:18,320 So then they're normally doing them-- 64 00:04:18,320 --> 00:04:22,820 the searching, the locomotion and searching, then stalking, 65 00:04:22,820 --> 00:04:25,550 then pouncing, and then the killing 66 00:04:25,550 --> 00:04:34,770 bite, usually in that order. 67 00:04:34,770 --> 00:04:40,710 So how frequently does a cat perform 68 00:04:40,710 --> 00:04:43,270 each of these behaviors? 69 00:04:43,270 --> 00:04:49,920 Well, they perform stalking a lot more than they pounce, 70 00:04:49,920 --> 00:04:51,800 because they have to stalk, they have 71 00:04:51,800 --> 00:04:56,715 to search for prey the most before they find any. 72 00:04:56,715 --> 00:04:58,840 So they're going to spend the most time doing that. 73 00:04:58,840 --> 00:05:01,419 And then when they see them, they have to stalk them. 74 00:05:01,419 --> 00:05:03,460 And they're going to do that a lot more than they 75 00:05:03,460 --> 00:05:05,959 will actually pounce, because they don't get the opportunity 76 00:05:05,959 --> 00:05:08,190 to pounce that often. 77 00:05:08,190 --> 00:05:10,180 The animals move away, the animals 78 00:05:10,180 --> 00:05:14,080 smell them, and run away, and so forth. 79 00:05:18,430 --> 00:05:22,050 And of course the killing bite is executed the least 80 00:05:22,050 --> 00:05:26,770 frequently, because sometimes when they pounce on an animal 81 00:05:26,770 --> 00:05:29,022 the animal still escapes. 82 00:05:29,022 --> 00:05:30,950 When we talk about escape behavior, 83 00:05:30,950 --> 00:05:34,580 you'll see examples of that on videos. 84 00:05:34,580 --> 00:05:39,870 So that's the action that's done the least. 85 00:05:39,870 --> 00:05:45,430 Well, that means that the action-specific potential, 86 00:05:45,430 --> 00:05:48,740 the motivation, to do those different things is building up 87 00:05:48,740 --> 00:05:49,970 at a different rate. 88 00:05:49,970 --> 00:05:55,690 They're much more motivated to do searching locomotion 89 00:05:55,690 --> 00:05:57,610 than they are those other things. 90 00:05:57,610 --> 00:06:01,480 Because they have to do it the most. 91 00:06:01,480 --> 00:06:04,720 We'll come back to this. 92 00:06:04,720 --> 00:06:09,840 But for those frequently used action patterns, 93 00:06:09,840 --> 00:06:13,620 the thresholds be lowered quite frequently. 94 00:06:13,620 --> 00:06:22,160 Take, for example, flying in a little wren, say. 95 00:06:22,160 --> 00:06:26,650 And compared to flying in a goose. 96 00:06:26,650 --> 00:06:27,760 You know? 97 00:06:27,760 --> 00:06:32,610 That little wren can't stop for more than a few seconds 98 00:06:32,610 --> 00:06:35,030 before he's flying again. 99 00:06:35,030 --> 00:06:43,730 They flit around very frequently. 100 00:06:43,730 --> 00:06:55,064 Whereas the goose, once he flies-- I 101 00:06:55,064 --> 00:06:56,480 don't want to mute it, I just want 102 00:06:56,480 --> 00:06:57,890 to turn the amplitude down. 103 00:06:57,890 --> 00:07:01,095 But this isn't-- there we go. 104 00:07:05,900 --> 00:07:07,730 OK, so the goose, when he flies, he 105 00:07:07,730 --> 00:07:09,390 won't fly again for quite awhile. 106 00:07:09,390 --> 00:07:15,170 Unless a stimulus, like a predator, 107 00:07:15,170 --> 00:07:19,840 causes a rapid rise in the motivation to fly. 108 00:07:19,840 --> 00:07:24,490 But in most cases, if he's not being disturbed by predators, 109 00:07:24,490 --> 00:07:26,050 he won't fly again for quite awhile. 110 00:07:26,050 --> 00:07:27,760 Whereas the wren is flying much more. 111 00:07:27,760 --> 00:07:31,480 So the rate of build-up is different from species 112 00:07:31,480 --> 00:07:34,040 to species for the very same action better. 113 00:07:34,040 --> 00:07:36,510 And it's different for different fixed action 114 00:07:36,510 --> 00:07:37,720 patterns in the same species. 115 00:07:43,670 --> 00:07:51,035 Let's talk about the threshold for this responding to stimuli 116 00:07:51,035 --> 00:07:53,100 that elicit a fixed action pattern. 117 00:07:55,700 --> 00:08:03,370 As the motivation builds up, the threshold-- 118 00:08:03,370 --> 00:08:09,920 the amount of stimulation needed to get the action pattern-- 119 00:08:09,920 --> 00:08:11,790 goes down. 120 00:08:11,790 --> 00:08:14,600 Look at hunger and feeding. 121 00:08:14,600 --> 00:08:17,160 We've mentioned this before, and it's obvious 122 00:08:17,160 --> 00:08:18,390 when you think about it. 123 00:08:18,390 --> 00:08:22,630 With the hungrier the animal or person 124 00:08:22,630 --> 00:08:26,900 is, the less discriminating he is. 125 00:08:26,900 --> 00:08:30,800 Why do we have dessert at the end of the meal? 126 00:08:30,800 --> 00:08:33,350 We're not as hungry. 127 00:08:33,350 --> 00:08:37,169 So it's often the most palatable thing. 128 00:08:37,169 --> 00:08:39,190 Of course, there are exceptions, but most of us 129 00:08:39,190 --> 00:08:42,280 like sweet things. 130 00:08:42,280 --> 00:08:45,620 Some countries don't even serve dessert. 131 00:08:45,620 --> 00:08:46,570 Like in China. 132 00:08:46,570 --> 00:08:49,350 It's an American habit. 133 00:08:49,350 --> 00:08:53,250 OK, but of course it occurs in many countries that have it. 134 00:08:53,250 --> 00:08:56,480 The desert is last, because it's the most palatable thing. 135 00:08:56,480 --> 00:09:00,060 And they will still eat dessert, even though they're not 136 00:09:00,060 --> 00:09:04,140 hungry for other foods anymore. 137 00:09:04,140 --> 00:09:06,970 And as I mentioned, if you have a child that's very finicky, 138 00:09:06,970 --> 00:09:10,320 that's because he's so well-fed. 139 00:09:10,320 --> 00:09:12,005 He's much less finicky if he's hungry. 140 00:09:14,970 --> 00:09:17,820 And if you don't like certain insert something, 141 00:09:17,820 --> 00:09:20,080 and all your friends do like it, well just 142 00:09:20,080 --> 00:09:25,520 don't eat for awhile if you want to start liking it. 143 00:09:25,520 --> 00:09:27,100 And then you'll get used to it. 144 00:09:32,650 --> 00:09:34,230 I thought I'd never like beer. 145 00:09:34,230 --> 00:09:36,680 I hated beer when I was a kid. 146 00:09:36,680 --> 00:09:39,816 My brother would be drinking beer. 147 00:09:39,816 --> 00:09:42,080 Couldn't stand the stuff. 148 00:09:42,080 --> 00:09:46,830 But then, on a real hot day, you get really thirsty, 149 00:09:46,830 --> 00:09:51,900 and your thresholds are lowered, your thresholds for drinking. 150 00:09:51,900 --> 00:09:54,990 And so, you like it a little better. 151 00:09:54,990 --> 00:09:57,680 And then I got used to it, and now I can drink beer. 152 00:09:57,680 --> 00:09:59,810 Still don't like it as well as some people do. 153 00:10:04,770 --> 00:10:09,060 Reading sexual attraction, really obvious. 154 00:10:09,060 --> 00:10:12,800 A horse breeder, if he he's got a stallion, 155 00:10:12,800 --> 00:10:17,225 let's say, and he wants to breed that stallion. 156 00:10:17,225 --> 00:10:22,460 If the stallion is worth a lot, he gets money for that. 157 00:10:22,460 --> 00:10:25,270 But if he's being paid, that stallion has to perform. 158 00:10:25,270 --> 00:10:26,330 So what does he do? 159 00:10:26,330 --> 00:10:31,000 He do he does not let that stallion copulate 160 00:10:31,000 --> 00:10:32,650 for a long period of time. 161 00:10:32,650 --> 00:10:39,930 So motivation to breed builds up in the animal. 162 00:10:39,930 --> 00:10:44,540 And if you build it up enough, he'll breed with a mule. 163 00:10:44,540 --> 00:10:46,820 That's how you get donkeys. 164 00:10:46,820 --> 00:10:49,360 And so that's important. 165 00:10:49,360 --> 00:10:51,020 And it happens in humans, too. 166 00:10:51,020 --> 00:10:54,470 There's an amusing story there in the Lorenz reading 167 00:10:54,470 --> 00:11:00,000 about a story told to Lorenz by a ship captain he knew, 168 00:11:00,000 --> 00:11:03,350 and how he felt after being at sea for a long time. 169 00:11:03,350 --> 00:11:06,300 He came back, and he said, every woman in town 170 00:11:06,300 --> 00:11:09,370 looks like Helen of Troy. 171 00:11:09,370 --> 00:11:11,190 But after I've been here a couple weeks, 172 00:11:11,190 --> 00:11:14,740 he said, so many ugly ones. 173 00:11:14,740 --> 00:11:15,690 What's happened? 174 00:11:15,690 --> 00:11:16,940 Threshold lowering. 175 00:11:21,750 --> 00:11:25,370 And this really explains, to a large degree, 176 00:11:25,370 --> 00:11:32,410 the phenomenon we call in vacuo reactions, vacuum activity, 177 00:11:32,410 --> 00:11:35,410 another term used in ethology. 178 00:11:35,410 --> 00:11:41,520 It literally means an instinctive behavior pattern 179 00:11:41,520 --> 00:11:43,920 that occurs without any stimulus. 180 00:11:43,920 --> 00:11:49,890 That would be the literal meaning of vacuum activity. 181 00:11:49,890 --> 00:11:52,900 But in fact, it seems to be a case 182 00:11:52,900 --> 00:11:56,730 of extreme threshold lowering. 183 00:11:56,730 --> 00:12:01,280 The thresholds can get so low, that we don't even 184 00:12:01,280 --> 00:12:04,090 notice the stimuli the animals are responding to. 185 00:12:04,090 --> 00:12:07,420 And Lorenz talks about how when he was young, 186 00:12:07,420 --> 00:12:09,750 he had a pet starling. 187 00:12:09,750 --> 00:12:14,180 And he could be eating dinner with his family, 188 00:12:14,180 --> 00:12:17,800 and that he would notice that the starling seemed 189 00:12:17,800 --> 00:12:23,550 to be catching and feeding on flies up near the ceiling. 190 00:12:23,550 --> 00:12:25,590 And he couldn't see the flies. 191 00:12:25,590 --> 00:12:27,850 So he tried getting a ladder and going up there 192 00:12:27,850 --> 00:12:30,420 and see if there were any flies. 193 00:12:30,420 --> 00:12:35,300 And he convinced himself that there were not. 194 00:12:35,300 --> 00:12:39,020 And yet the starling was there, showing the fixed action 195 00:12:39,020 --> 00:12:45,890 pattern of searching for, catching, and eating the flies. 196 00:12:45,890 --> 00:12:50,715 So that's called in vacuo activity or reactions. 197 00:12:55,090 --> 00:13:00,960 Some of you that, if you keep rats or mice in cages, 198 00:13:00,960 --> 00:13:04,070 and they don't have any nesting material, 199 00:13:04,070 --> 00:13:05,899 they have a motivation to nest. 200 00:13:05,899 --> 00:13:07,690 And if they're deprived of nesting material 201 00:13:07,690 --> 00:13:10,304 for a long period of time, they'll 202 00:13:10,304 --> 00:13:11,970 try to build a nest with their own tail. 203 00:13:15,660 --> 00:13:21,280 Canaries will build nests with their own feathers. 204 00:13:21,280 --> 00:13:31,770 And mallard drakes, when they're highly motivated to mate, 205 00:13:31,770 --> 00:13:34,250 they're also very aggressive against other males. 206 00:13:34,250 --> 00:13:40,450 And they'll actually attack their own tails, 207 00:13:40,450 --> 00:13:42,530 because the thresholds are so low. 208 00:13:42,530 --> 00:13:45,500 It doesn't take much of the stimulus. 209 00:13:45,500 --> 00:13:49,750 They just need certain key stimuli, 210 00:13:49,750 --> 00:13:51,950 and if thresholds are low enough, 211 00:13:51,950 --> 00:13:55,310 their own tail will be enough to elicit the behavior. 212 00:13:55,310 --> 00:14:00,300 Ostriches, deprived of their usual method of feeding 213 00:14:00,300 --> 00:14:05,860 of grass, they will pluck grass that is not even there. 214 00:14:05,860 --> 00:14:08,660 The same you will notice this in rodents, 215 00:14:08,660 --> 00:14:14,490 if you don't-- you know, we give them rat pellets, we call them. 216 00:14:14,490 --> 00:14:19,900 Well, why do we give them food that's so hard? 217 00:14:19,900 --> 00:14:25,240 In fact it's mixed with material that grinds their teeth down. 218 00:14:25,240 --> 00:14:26,680 Well they have to. 219 00:14:26,680 --> 00:14:30,220 Because, in the case of rodents, the teeth keep growing, 220 00:14:30,220 --> 00:14:33,730 these incisor teeth on both bottom and top. 221 00:14:33,730 --> 00:14:36,130 The same is true of hamsters and mice. 222 00:14:36,130 --> 00:14:37,770 They just keep growing. 223 00:14:37,770 --> 00:14:39,760 So they're highly motivated to gnaw, 224 00:14:39,760 --> 00:14:42,150 and if you deprive them of things 225 00:14:42,150 --> 00:14:44,130 to gnaw on-- let's see, say you're 226 00:14:44,130 --> 00:14:46,650 feeding them wet mash or something, 227 00:14:46,650 --> 00:14:48,120 they can't wear their teeth down. 228 00:14:48,120 --> 00:14:51,710 They will chew on the metal cage. 229 00:14:51,710 --> 00:14:56,960 They'll chew on anything they get their teeth around. 230 00:14:56,960 --> 00:15:00,210 Reminds me of some dogs. 231 00:15:00,210 --> 00:15:02,060 I don't know what their fixed action 232 00:15:02,060 --> 00:15:04,440 patterns, how much of its nesting, of whatever, 233 00:15:04,440 --> 00:15:08,810 but some dogs also can mess up your house 234 00:15:08,810 --> 00:15:12,630 quite a bit because of what they do to shoes, 235 00:15:12,630 --> 00:15:16,030 blankets, and so forth. 236 00:15:16,030 --> 00:15:19,480 So with a lot of threshold lowering, all you need 237 00:15:19,480 --> 00:15:22,290 is a very small stimulus. 238 00:15:22,290 --> 00:15:27,210 It's almost like an internal reservoir. 239 00:15:27,210 --> 00:15:32,100 It's sort of a metaphor for the action-specific potential. 240 00:15:32,100 --> 00:15:34,430 Builds up to a point it just starts spilling over. 241 00:15:39,880 --> 00:15:42,690 Now we talked last time about the different components 242 00:15:42,690 --> 00:15:48,270 of fixed action patterns, and we'll use these terms a lot. 243 00:15:48,270 --> 00:15:51,520 There was a component that wasn't defined for a long time, 244 00:15:51,520 --> 00:15:54,960 until this guy, Wallace Craig, defined it. 245 00:15:54,960 --> 00:16:02,240 It corresponds to the level of the action-specific potential. 246 00:16:02,240 --> 00:16:05,550 But before they even used that theoretical term, 247 00:16:05,550 --> 00:16:07,720 this behavior had been described. 248 00:16:07,720 --> 00:16:08,525 What is it? 249 00:16:08,525 --> 00:16:12,140 What did Craig talk about? 250 00:16:12,140 --> 00:16:17,720 Appetitive behavior-- it's usually the appetitive behavior 251 00:16:17,720 --> 00:16:19,950 of some sort, usually locomotion, 252 00:16:19,950 --> 00:16:22,760 searching behavior and orienting, 253 00:16:22,760 --> 00:16:24,610 has the lowest threshold. 254 00:16:24,610 --> 00:16:31,250 So when an animal gets hungry, the action, 255 00:16:31,250 --> 00:16:36,250 the series of actions that compose a fixed action 256 00:16:36,250 --> 00:16:39,340 pattern, the part with the lowest threshold 257 00:16:39,340 --> 00:16:42,010 is appetitive behavior, searching behavior. 258 00:16:42,010 --> 00:16:45,024 So they literally search for the stimulus 259 00:16:45,024 --> 00:16:46,815 that will lead to the rest of the behavior. 260 00:16:50,800 --> 00:16:58,850 And finding appetitive behavior for some fixed action patterns, 261 00:16:58,850 --> 00:17:03,520 especially in humans, has led to quite a bit of controversy. 262 00:17:03,520 --> 00:17:08,250 And the controversy that Lorenz got into concerned 263 00:17:08,250 --> 00:17:10,355 what he called an appetite for aggression. 264 00:17:14,069 --> 00:17:18,520 For example, the second one, the gray leg gander, 265 00:17:18,520 --> 00:17:25,390 when he's in an aggressive mood, because he's in a mating mood, 266 00:17:25,390 --> 00:17:32,600 he literally looks for other ganders to fight with. 267 00:17:32,600 --> 00:17:35,210 And many, many animals are like this. 268 00:17:35,210 --> 00:17:36,760 And so he applied this to humans. 269 00:17:36,760 --> 00:17:39,610 He said, think of the young men who 270 00:17:39,610 --> 00:17:42,040 roam the streets looking for trouble. 271 00:17:42,040 --> 00:17:43,130 What are they doing? 272 00:17:43,130 --> 00:17:44,850 It's the same thing. 273 00:17:44,850 --> 00:17:51,540 They have a motivation to get into fights. 274 00:17:51,540 --> 00:17:54,900 Maybe our aggressive video games are 275 00:17:54,900 --> 00:17:59,440 able to satisfy that urge for a lot of young men. 276 00:17:59,440 --> 00:18:01,620 But if you look at aggressive video games 277 00:18:01,620 --> 00:18:04,270 and see who plays them, you'll see it's much more males 278 00:18:04,270 --> 00:18:05,370 than females. 279 00:18:05,370 --> 00:18:08,550 So there are girls that do it, too. 280 00:18:08,550 --> 00:18:13,780 And young men that seem to have no real desire to fight at all 281 00:18:13,780 --> 00:18:17,190 can get extremely involved in these games. 282 00:18:17,190 --> 00:18:21,170 And they can feel great triumph when they win. 283 00:18:21,170 --> 00:18:27,270 I remember when my son was growing up-- 284 00:18:27,270 --> 00:18:33,580 this is long before he came to MIT-- he went to the MIT camp. 285 00:18:33,580 --> 00:18:40,245 And the counselor found out that all the young men in his group, 286 00:18:40,245 --> 00:18:42,770 were mostly middle school age, they 287 00:18:42,770 --> 00:18:46,430 loved this particular video game that he also played. 288 00:18:46,430 --> 00:18:49,070 It's like many MIT students. 289 00:18:49,070 --> 00:18:51,170 So he organized a tournament. 290 00:18:51,170 --> 00:18:54,380 And the kids got so involved in it. 291 00:18:54,380 --> 00:18:57,770 And my son, I could tell he's not aggressive, 292 00:18:57,770 --> 00:19:00,680 but he felt great triumph when he beat the counselor 293 00:19:00,680 --> 00:19:02,900 in the first part of the tournament. 294 00:19:02,900 --> 00:19:05,720 Of course, they continued the tournament and the customer 295 00:19:05,720 --> 00:19:07,550 beat him the second time. 296 00:19:07,550 --> 00:19:13,540 But you could tell that he had that drive. 297 00:19:13,540 --> 00:19:15,855 This all happened after Lorenz, of course, 298 00:19:15,855 --> 00:19:17,190 had done his studies. 299 00:19:17,190 --> 00:19:21,540 I don't know what he would say about the motivation 300 00:19:21,540 --> 00:19:23,280 behind doing these video games. 301 00:19:23,280 --> 00:19:28,230 But I'm sure what I'm saying is some part of the explanation. 302 00:19:28,230 --> 00:19:30,660 There were many experiments done with jewel fish, 303 00:19:30,660 --> 00:19:32,810 because of their fighting behavior. 304 00:19:32,810 --> 00:19:37,970 And in one of the experiments, male jewel fish that 305 00:19:37,970 --> 00:19:41,430 wanted to fight, he could teach them 306 00:19:41,430 --> 00:19:46,280 a maze when the only reward was getting 307 00:19:46,280 --> 00:19:51,280 a visual view of another male jewel fish. 308 00:19:51,280 --> 00:19:56,530 Also, they changed coloration when they're in that mood. 309 00:19:56,530 --> 00:20:03,540 And just seeing other male and being able to attack the glass, 310 00:20:03,540 --> 00:20:05,170 they didn't actually fight. 311 00:20:05,170 --> 00:20:09,200 You didn't need to get them to fight to get that reward. 312 00:20:09,200 --> 00:20:15,400 And so it might seem strange to you, but being hungry 313 00:20:15,400 --> 00:20:17,630 is necessary to be rewarded by food. 314 00:20:17,630 --> 00:20:20,850 So actually, we like to be hungry. 315 00:20:20,850 --> 00:20:23,570 Just not too hungry. 316 00:20:23,570 --> 00:20:28,720 Because without being hungry, food isn't rewarding. 317 00:20:28,720 --> 00:20:30,590 And it's the same for the aggressive drive. 318 00:20:34,470 --> 00:20:38,610 So I just discussed briefly here the reactions people 319 00:20:38,610 --> 00:20:40,390 have had against that. 320 00:20:40,390 --> 00:20:43,940 Remember, for a long time, especially 321 00:20:43,940 --> 00:20:48,290 in America and in Russia, there was a pretty strong bias 322 00:20:48,290 --> 00:20:50,820 against any behavior that couldn't be explained 323 00:20:50,820 --> 00:20:53,290 in terms of a stimulus response model. 324 00:20:53,290 --> 00:20:56,100 People come to believe that a certain model is 325 00:20:56,100 --> 00:20:57,927 adequate to explain all behavior, 326 00:20:57,927 --> 00:21:00,010 they don't like it when there's some behavior that 327 00:21:00,010 --> 00:21:00,801 can't be explained. 328 00:21:00,801 --> 00:21:03,910 So they're going to try to find some way to explain it away. 329 00:21:07,840 --> 00:21:10,530 So how could there be an appetite for aggression? 330 00:21:10,530 --> 00:21:13,120 Must be stimulus for it. 331 00:21:13,120 --> 00:21:15,975 And yes, they're always responding to some stimuli, 332 00:21:15,975 --> 00:21:18,740 but the stimulus can be minimal, and the thresholds 333 00:21:18,740 --> 00:21:24,370 can change drastically due to an internal state that's changing. 334 00:21:24,370 --> 00:21:26,080 And of course we know there was a bias 335 00:21:26,080 --> 00:21:30,250 against instinctive behavior in general, especially in humans. 336 00:21:30,250 --> 00:21:31,770 But not only in humans. 337 00:21:31,770 --> 00:21:37,370 I read studies written in the '30s, especially, 338 00:21:37,370 --> 00:21:42,420 before World War II, where the experimenters went 339 00:21:42,420 --> 00:21:46,670 to great lengths to try to prove that some behavior that 340 00:21:46,670 --> 00:21:52,870 appeared seemed to be innate because it appeared very early, 341 00:21:52,870 --> 00:21:54,555 was actually learned in utero. 342 00:21:57,440 --> 00:22:02,650 It was believed that, for example, the birds that 343 00:22:02,650 --> 00:22:04,840 have to peck their way out of an egg, 344 00:22:04,840 --> 00:22:10,090 they actually learned to do that in the uterus, or in the egg 345 00:22:10,090 --> 00:22:12,610 before they hatched. 346 00:22:12,610 --> 00:22:14,550 And they went to great lengths to show 347 00:22:14,550 --> 00:22:16,295 that there could be such experience. 348 00:22:19,260 --> 00:22:24,970 Now people are not quite so extreme. 349 00:22:24,970 --> 00:22:29,130 Although, there are still people in the humanities, 350 00:22:29,130 --> 00:22:36,760 and even in sociology, that believe that unlearned behavior 351 00:22:36,760 --> 00:22:39,780 is not important in explaining behavior. 352 00:22:43,190 --> 00:22:45,880 So let's go back to this topic of internal readiness, 353 00:22:45,880 --> 00:22:49,490 the action specific potential, and how it varies, just 354 00:22:49,490 --> 00:22:52,270 to give some examples. 355 00:22:52,270 --> 00:22:55,050 I mentioned how flying builds up at different rates 356 00:22:55,050 --> 00:22:58,120 in different birds. 357 00:22:58,120 --> 00:23:03,320 But take the example-- I think this is described in the Lorenz 358 00:23:03,320 --> 00:23:07,220 chapter-- from Paul Leyhausen's studies of cats. 359 00:23:07,220 --> 00:23:12,950 Leyhausen studied a number of different species of cats, 360 00:23:12,950 --> 00:23:15,850 found the same fixed action patterns, 361 00:23:15,850 --> 00:23:18,260 with slight variations, of course, 362 00:23:18,260 --> 00:23:20,620 in different species of cat, including 363 00:23:20,620 --> 00:23:26,170 the very large Asian and African cats and domestic cats 364 00:23:26,170 --> 00:23:27,670 in America and Europe. 365 00:23:31,230 --> 00:23:36,750 And if you have a cat that's a hunter, that 366 00:23:36,750 --> 00:23:41,270 is he's been exposed to hunting-- he's watched 367 00:23:41,270 --> 00:23:44,350 his mother hunt-- he will become a hunter. 368 00:23:44,350 --> 00:23:47,700 And he's deprived of hunting for a long period, what 369 00:23:47,700 --> 00:23:50,840 does that cat do if you put him in a room full of mice? 370 00:23:53,660 --> 00:23:59,280 Well, he will initially attack and kill a few of those mice. 371 00:23:59,280 --> 00:24:01,450 Then what does he do? 372 00:24:01,450 --> 00:24:03,150 Does he just stop? 373 00:24:03,150 --> 00:24:04,050 No. 374 00:24:04,050 --> 00:24:09,470 He continues to stalk and pounce on mice. 375 00:24:09,470 --> 00:24:13,530 But he stops executing the killing bite. 376 00:24:13,530 --> 00:24:17,220 He will jump on them, swat them with this paws, 377 00:24:17,220 --> 00:24:19,720 and it looks like he's playing with them. 378 00:24:19,720 --> 00:24:22,830 And then eventually he will stalk them, 379 00:24:22,830 --> 00:24:26,450 but he won't even pounce. 380 00:24:26,450 --> 00:24:31,260 And then eventually he appears to be searching for them. 381 00:24:31,260 --> 00:24:34,050 He's very alert, pricks up his ears, he's watching them, 382 00:24:34,050 --> 00:24:38,560 he's showing all the orienting movements of a searching cat. 383 00:24:38,560 --> 00:24:43,090 But now he's not doing any of those things. 384 00:24:43,090 --> 00:24:46,980 And eventually, of course, he'll go to sleep. 385 00:24:46,980 --> 00:24:51,890 So that's because the rate at which 386 00:24:51,890 --> 00:24:55,280 the action-specific potential behind each 387 00:24:55,280 --> 00:24:58,070 of those fixed action patterns, that 388 00:24:58,070 --> 00:25:03,490 have been combined in attack behavior of the cat, 389 00:25:03,490 --> 00:25:06,020 builds up at a different rate, depending 390 00:25:06,020 --> 00:25:10,365 on how frequently it's needed in natural life of these animals. 391 00:25:13,680 --> 00:25:17,070 Can you answer this question for me? 392 00:25:17,070 --> 00:25:22,020 Is it true that cats or dogs hunt only in order to eat? 393 00:25:26,490 --> 00:25:31,210 And describe an experiment to test that idea. 394 00:25:31,210 --> 00:25:33,135 Do they hunt only in order to eat? 395 00:25:36,190 --> 00:25:38,690 Does a cat that's a ratter, and we 396 00:25:38,690 --> 00:25:41,610 know he hunts for rats and mice, does he 397 00:25:41,610 --> 00:25:43,120 do that just in order to eat? 398 00:25:43,120 --> 00:25:44,540 Does he do it because he's hungry? 399 00:25:47,370 --> 00:25:49,550 Well for one thing, how can that be? 400 00:25:49,550 --> 00:25:52,460 People that keep pet cats are feeding them. 401 00:25:52,460 --> 00:25:54,630 They feed them every day. 402 00:25:54,630 --> 00:25:56,700 These are not hungry cats. 403 00:25:56,700 --> 00:25:59,620 Well, do they just go out near feeding time? 404 00:25:59,620 --> 00:26:02,470 No. 405 00:26:02,470 --> 00:26:06,400 Well how can you prove that the motivation to eat 406 00:26:06,400 --> 00:26:14,160 and the motivation to hunt are quite separate? 407 00:26:14,160 --> 00:26:22,100 Well, you can deprive the cat of opportunities to hunt, 408 00:26:22,100 --> 00:26:25,450 so his eagerness to hunt builds up. 409 00:26:28,980 --> 00:26:33,690 And now we put him in a situation 410 00:26:33,690 --> 00:26:39,055 where he has to, say, cross over a dish of tuna 411 00:26:39,055 --> 00:26:43,550 fish, his favorite food, just in order to get out and hunt. 412 00:26:43,550 --> 00:26:44,310 What does he do? 413 00:26:44,310 --> 00:26:47,160 Does he run to the tuna fish? 414 00:26:47,160 --> 00:26:51,680 No, he'll leap right over it to get out there to hunt. 415 00:26:51,680 --> 00:26:54,100 And that's been seen in brain stimulation studies, where 416 00:26:54,100 --> 00:26:56,140 you can stimulate the mood that causes 417 00:26:56,140 --> 00:26:59,120 them to go into a hunting mood. 418 00:26:59,120 --> 00:27:01,960 They'll leap over dishes, everything, 419 00:27:01,960 --> 00:27:06,860 just to get at a mouse or at rat. 420 00:27:06,860 --> 00:27:09,240 Because the motivation to hunt is quite separate. 421 00:27:12,340 --> 00:27:15,620 So it's pretty easy to do an experiment to show that, 422 00:27:15,620 --> 00:27:17,100 and it has certainly been done. 423 00:27:21,160 --> 00:27:24,370 And similarly, we can talk about species 424 00:27:24,370 --> 00:27:30,680 that they don't hunt and kill in the same way that the cats do, 425 00:27:30,680 --> 00:27:35,505 but they still hunt for insects, like Lorenz's starlings. 426 00:27:38,780 --> 00:27:42,360 Those starlings, normally when they feed, 427 00:27:42,360 --> 00:27:45,860 they are poking their bills into the bark of trees, 428 00:27:45,860 --> 00:27:48,920 or in leaves. 429 00:27:48,920 --> 00:27:52,050 They're poking, using their bills to poke. 430 00:27:52,050 --> 00:27:55,140 Well, if it's a pet starling, and you're feeding him 431 00:27:55,140 --> 00:27:59,850 all the time so he's not hungry, that animal 432 00:27:59,850 --> 00:28:02,890 will feed in order to poke. 433 00:28:02,890 --> 00:28:07,030 Where the normal sequence would be poking in order to get food. 434 00:28:07,030 --> 00:28:12,210 But now, he will feed just to be able to poke. 435 00:28:12,210 --> 00:28:14,910 The cactus finch on the Galapagos 436 00:28:14,910 --> 00:28:18,440 is a very interesting bird. 437 00:28:18,440 --> 00:28:22,100 Here you see a finch, and it looks 438 00:28:22,100 --> 00:28:24,710 like he's got this long extension of his beak. 439 00:28:24,710 --> 00:28:30,610 What it is, it's a cactus thorn that the bird has found. 440 00:28:30,610 --> 00:28:34,530 And he uses that, and all cactus finches do this, 441 00:28:34,530 --> 00:28:39,120 they get that thorn and they use that to poke deeper 442 00:28:39,120 --> 00:28:42,570 into crevices in the cactus and other places 443 00:28:42,570 --> 00:28:43,640 in order to get food. 444 00:28:43,640 --> 00:28:48,690 And if you deprive that cactus finch of opportunity 445 00:28:48,690 --> 00:28:52,930 to use the thorn that way, they're 446 00:28:52,930 --> 00:28:56,360 highly motivated to do that. 447 00:28:56,360 --> 00:29:01,370 Even if he's well fed, he will search for the thorn, 448 00:29:01,370 --> 00:29:05,097 take the thorn, and he'll be out poking. 449 00:29:05,097 --> 00:29:06,555 Because it's a separate motivation. 450 00:29:13,800 --> 00:29:17,840 Now I want to talk specifically about the sensory side 451 00:29:17,840 --> 00:29:20,140 of these innate behavior patterns. 452 00:29:24,050 --> 00:29:26,970 We call the mechanism on that side 453 00:29:26,970 --> 00:29:29,440 the innate releasing mechanism. 454 00:29:29,440 --> 00:29:31,980 That was a theoretical term introduced 455 00:29:31,980 --> 00:29:34,330 by ethologists who did not actually 456 00:29:34,330 --> 00:29:38,250 study the nervous system. 457 00:29:38,250 --> 00:29:42,100 But they knew there was an innate releasing mechanism. 458 00:29:45,030 --> 00:29:50,410 I've seen this statement, and I want you to criticize it. 459 00:29:50,410 --> 00:29:53,910 "The innate releasing mechanism responds to complex stimulus 460 00:29:53,910 --> 00:29:56,670 configurations, and triggers a behavioral response 461 00:29:56,670 --> 00:29:58,830 from the organism." 462 00:29:58,830 --> 00:30:00,900 Sort of the definition of innate behavior, 463 00:30:00,900 --> 00:30:02,470 in some people's view. 464 00:30:02,470 --> 00:30:03,970 But what's wrong with it? 465 00:30:07,830 --> 00:30:11,500 There's a couple of glaring things wrong with it. 466 00:30:11,500 --> 00:30:18,560 First of all, these innate releasing mechanisms 467 00:30:18,560 --> 00:30:23,890 are at least, at the onset when the animal is young, 468 00:30:23,890 --> 00:30:26,875 are not responding to complex stimulus configurations. 469 00:30:26,875 --> 00:30:30,320 They are responding to very simple stimuli. 470 00:30:33,040 --> 00:30:39,440 And if the response is, say, of the young to the mother, 471 00:30:39,440 --> 00:30:42,950 he doesn't respond to her as an individual. 472 00:30:42,950 --> 00:30:46,850 He responds to specific stimuli presented by that mother. 473 00:30:46,850 --> 00:30:48,950 Like the herring gulls responding 474 00:30:48,950 --> 00:30:51,260 to the orange spot on the mother's beak. 475 00:30:51,260 --> 00:30:54,740 And an orange spot on a pencil will elicit the same kind 476 00:30:54,740 --> 00:30:58,100 of gaping behavior for feeding. 477 00:30:58,100 --> 00:31:01,400 So the stimulus is generally very simple. 478 00:31:01,400 --> 00:31:06,520 And they can be multiple, but they're very simple stimuli. 479 00:31:06,520 --> 00:31:09,040 So that's the first thing that's wrong with it. 480 00:31:09,040 --> 00:31:14,120 And now, what about, I say elicits the behavior? 481 00:31:14,120 --> 00:31:16,550 As if we're talking about a reflex? 482 00:31:16,550 --> 00:31:19,110 But we're not talking about reflexes. 483 00:31:19,110 --> 00:31:22,740 The response will not occur if the motivation 484 00:31:22,740 --> 00:31:23,800 level isn't high. 485 00:31:23,800 --> 00:31:27,590 That action specific potential. 486 00:31:27,590 --> 00:31:30,550 So there's no inevitable elicitation 487 00:31:30,550 --> 00:31:33,695 of these fixed action patterns, the fixed motor component, 488 00:31:33,695 --> 00:31:37,200 the fixed motor pattern component of a fixed action 489 00:31:37,200 --> 00:31:37,700 pattern. 490 00:31:37,700 --> 00:31:40,100 And that's what's wrong with the statement. 491 00:31:40,100 --> 00:31:43,250 We're not dealing with reflexes. 492 00:31:43,250 --> 00:31:46,640 So let's just give examples of the simplicity 493 00:31:46,640 --> 00:31:49,020 of the key stimuli. 494 00:31:49,020 --> 00:31:52,010 I just mentioned the herring gull chicks. 495 00:31:52,010 --> 00:31:54,430 You remember the stickleback fish. 496 00:31:54,430 --> 00:31:57,830 Very simple stimuli in the female 497 00:31:57,830 --> 00:32:00,830 that the male responds to in order 498 00:32:00,830 --> 00:32:05,480 to initiate his specific actions, 499 00:32:05,480 --> 00:32:08,970 and leading the female to his nest, 500 00:32:08,970 --> 00:32:13,470 in order to get her to lay eggs in it. 501 00:32:13,470 --> 00:32:16,870 They're not complex stimuli. 502 00:32:16,870 --> 00:32:22,250 Just very simple shapes that resemble in some way 503 00:32:22,250 --> 00:32:25,580 a fish with a swollen belly. 504 00:32:25,580 --> 00:32:28,660 They don't even have to look much like fish to us. 505 00:32:31,840 --> 00:32:35,690 Lorenz mentions the stinging response 506 00:32:35,690 --> 00:32:38,020 of the female common tick. 507 00:32:38,020 --> 00:32:45,425 This was an example he got from Jakob von Uexkull in 1909. 508 00:32:45,425 --> 00:32:49,310 Very simple stimuli elicit that stinging response of the tick. 509 00:32:49,310 --> 00:32:53,440 A body temperature of about 37 degrees, 510 00:32:53,440 --> 00:32:55,390 and the smell of butyric acid. 511 00:32:55,390 --> 00:32:57,380 That's all it takes. 512 00:32:57,380 --> 00:33:04,960 And we know the tick can fall from a bush onto an animal, 513 00:33:04,960 --> 00:33:09,700 and we don't think tick is detecting surface temperatures 514 00:33:09,700 --> 00:33:10,600 at a distance. 515 00:33:10,600 --> 00:33:13,880 It probably responds to the odor of animals passing, 516 00:33:13,880 --> 00:33:16,400 but then the animal bumps the bush and so forth, 517 00:33:16,400 --> 00:33:19,130 and the ticks fall onto them. 518 00:33:21,910 --> 00:33:24,750 The stinging response, though, is triggered by those two 519 00:33:24,750 --> 00:33:27,110 stimuli that I mentioned, the surface 520 00:33:27,110 --> 00:33:29,140 temperature plus the odor. 521 00:33:29,140 --> 00:33:30,960 You can see the size of it. 522 00:33:30,960 --> 00:33:36,210 This is the tip of a ballpoint pen, this is a tick from a dog. 523 00:33:36,210 --> 00:33:41,510 And here are some deer ticks, which are a little smaller. 524 00:33:41,510 --> 00:33:45,480 Known for spreading diseases, like Lyme disease 525 00:33:45,480 --> 00:33:46,740 is spread by deer ticks. 526 00:33:51,080 --> 00:33:56,710 So he talks about the common cricket female's response 527 00:33:56,710 --> 00:33:57,890 to courting males. 528 00:33:57,890 --> 00:34:02,690 She's responding to the specific pitch of the male's courtship 529 00:34:02,690 --> 00:34:03,410 song. 530 00:34:03,410 --> 00:34:08,040 And different species of cricket have slightly different pitches 531 00:34:08,040 --> 00:34:09,800 of sound. 532 00:34:09,800 --> 00:34:14,690 So females of their own species will respond, just 533 00:34:14,690 --> 00:34:16,230 if the pitch is right. 534 00:34:16,230 --> 00:34:19,806 And there's something very similar in mosquitoes. 535 00:34:19,806 --> 00:34:24,509 The male responds to specific frequencies of the females wing 536 00:34:24,509 --> 00:34:25,179 beats. 537 00:34:25,179 --> 00:34:27,659 That buzzing sound we hear it makes, 538 00:34:27,659 --> 00:34:30,060 hear a female flying around. 539 00:34:30,060 --> 00:34:32,230 That's a very meaningful stimulus 540 00:34:32,230 --> 00:34:39,260 for the male looking for a female to mate with. 541 00:34:39,260 --> 00:34:44,350 So the stimuli are very simple. 542 00:34:44,350 --> 00:34:48,489 Let's talk about the contribution of Jerry Lettvin 543 00:34:48,489 --> 00:34:49,270 here at MIT. 544 00:34:52,409 --> 00:34:55,830 He died just a couple of years ago, 545 00:34:55,830 --> 00:35:00,350 but that was long after his retirement from MIT. 546 00:35:00,350 --> 00:35:04,940 Back in 1959, he published a paper 547 00:35:04,940 --> 00:35:09,420 that's one of the most highly cited papers in neuroscience. 548 00:35:09,420 --> 00:35:12,170 And the title was pretty far out, 549 00:35:12,170 --> 00:35:16,755 "What the Frog's Eye Tells the Frog's Brain." 550 00:35:16,755 --> 00:35:22,630 And it's a very scholarly paper that reports systematically 551 00:35:22,630 --> 00:35:28,370 the experiments that he did with Maturana, a South American 552 00:35:28,370 --> 00:35:32,220 scientist, and Warren McCulloch, and Pitts, 553 00:35:32,220 --> 00:35:38,780 who was another MIT scientist, an engineer, actually. 554 00:35:38,780 --> 00:35:42,710 And this is what they were studying. 555 00:35:42,710 --> 00:35:46,940 They were studying-- basically they 556 00:35:46,940 --> 00:35:50,640 were inspired by the behavior of the frog. 557 00:35:50,640 --> 00:35:54,985 This frog is responding to the visual stimulus 558 00:35:54,985 --> 00:35:57,770 of that bug on the leaf. 559 00:35:57,770 --> 00:36:00,930 The bug was flying, landed on the leaf. 560 00:36:00,930 --> 00:36:03,170 The frog waited. 561 00:36:03,170 --> 00:36:09,120 He might have made an orienting movement towards that bug, 562 00:36:09,120 --> 00:36:13,990 and then he simply waits until the bug is still. 563 00:36:13,990 --> 00:36:18,210 And then, out comes his tongue, it's sticky on the end. 564 00:36:20,990 --> 00:36:24,510 And normally they're pretty accurate. 565 00:36:24,510 --> 00:36:27,310 They only flick their tongue out when 566 00:36:27,310 --> 00:36:29,820 they're close enough to the bug. 567 00:36:32,960 --> 00:36:36,226 What Lettvin did, he's recording electrically, 568 00:36:36,226 --> 00:36:42,240 he used tiny electrodes in the frog's brain. 569 00:36:42,240 --> 00:36:46,850 Sometimes he did it just from the stump of the optic nerve. 570 00:36:46,850 --> 00:36:50,300 Because he was really recording from the axons coming 571 00:36:50,300 --> 00:36:52,180 from the retina. 572 00:36:52,180 --> 00:36:55,290 So it was the activity of retinal ganglian cells. 573 00:36:55,290 --> 00:36:59,170 This was the information that reached the midbrain 574 00:36:59,170 --> 00:37:01,490 tectum, the roof of the midbrain, 575 00:37:01,490 --> 00:37:09,130 where orienting movements are caused. 576 00:37:09,130 --> 00:37:11,100 And only after the animal orients, 577 00:37:11,100 --> 00:37:15,906 brings it to the stimulus to a certain part of the tectum, 578 00:37:15,906 --> 00:37:18,940 that then you get the tongue-flick response. 579 00:37:22,770 --> 00:37:24,860 So he was recording from the terminal arbors 580 00:37:24,860 --> 00:37:27,470 of axons coming from the retina. 581 00:37:27,470 --> 00:37:29,260 There was argument about that for awhile, 582 00:37:29,260 --> 00:37:32,860 but he knew when he wrote that paper what he must be recording 583 00:37:32,860 --> 00:37:38,790 from, because he had recorded even from axons in the nerve. 584 00:37:38,790 --> 00:37:44,200 And he showed four, actually there were five types of axons, 585 00:37:44,200 --> 00:37:48,460 but four major ones, that he described in great detail. 586 00:37:48,460 --> 00:37:53,250 The one that's the most well known, we call bug detectors. 587 00:37:53,250 --> 00:37:54,890 He didn't call it that in the paper, 588 00:37:54,890 --> 00:37:57,070 he called them net convexity detectors. 589 00:37:57,070 --> 00:38:02,760 But he did in his discussion, with these other scientists. 590 00:38:02,760 --> 00:38:06,250 He did talk about that what he had given 591 00:38:06,250 --> 00:38:15,660 was a detailed scientific description of a bug. 592 00:38:15,660 --> 00:38:20,200 The kind of stimulus that the bug presented to the frog. 593 00:38:20,200 --> 00:38:24,120 Those axons were part of what we call an innate releasing 594 00:38:24,120 --> 00:38:28,710 mechanism for detecting and orienting towards prey. 595 00:38:28,710 --> 00:38:35,570 He found another major type that has an easily discerned 596 00:38:35,570 --> 00:38:39,880 function was he called a dimming detector. 597 00:38:39,880 --> 00:38:42,520 And it's interesting that the dimming detectors 598 00:38:42,520 --> 00:38:47,290 were the activity of much larger axons. 599 00:38:47,290 --> 00:38:51,450 The most rapidly conducting axon in the optic nerve. 600 00:38:51,450 --> 00:38:53,430 And that's interesting because these 601 00:38:53,430 --> 00:38:58,140 are responding to sudden dimming of the field of the sort that 602 00:38:58,140 --> 00:39:01,830 occurs when there's approaching predator. 603 00:39:01,830 --> 00:39:06,200 And so the frog's responds in a completely different way. 604 00:39:06,200 --> 00:39:09,140 And note that it's very fast. 605 00:39:09,140 --> 00:39:13,570 Because speed is always at a premium when it concerns 606 00:39:13,570 --> 00:39:15,960 escape from predators. 607 00:39:15,960 --> 00:39:17,700 So the fastest conducting ones were 608 00:39:17,700 --> 00:39:24,590 responding to the dimming, which would be a visual stimulus very 609 00:39:24,590 --> 00:39:26,730 likely indicating a predator. 610 00:39:32,900 --> 00:39:36,700 Now because the key stimuli are so simple, 611 00:39:36,700 --> 00:39:40,010 you can get very maladaptive responses, in some cases. 612 00:39:40,010 --> 00:39:44,580 And these are a couple that he describes. 613 00:39:44,580 --> 00:39:46,110 First of all turkey chicks-- I'll 614 00:39:46,110 --> 00:39:49,460 say a little more about turkey chicks' responses 615 00:39:49,460 --> 00:39:53,850 to predators-- but first, what Lorenz says, 616 00:39:53,850 --> 00:39:58,190 they respond the very same way to a fat fly crawling 617 00:39:58,190 --> 00:40:03,570 across the ceiling as they do a hawk flying overhead. 618 00:40:03,570 --> 00:40:06,460 They don't discriminate. 619 00:40:06,460 --> 00:40:10,270 So they make maladaptive escape responses. 620 00:40:13,140 --> 00:40:17,020 And he says that young kestrels hand an innate response 621 00:40:17,020 --> 00:40:19,190 to water, they'll make bathing movements, 622 00:40:19,190 --> 00:40:22,120 but they'll do the same thing, they'll 623 00:40:22,120 --> 00:40:26,680 respond to the stimuli from a marble table top, 624 00:40:26,680 --> 00:40:29,280 because of the glassy surface. 625 00:40:29,280 --> 00:40:33,120 That's the only stimulus needed to elicit the bathing response. 626 00:40:33,120 --> 00:40:35,030 So it's obviously not very adaptive. 627 00:40:35,030 --> 00:40:38,090 These are just showing older kestrels. 628 00:40:38,090 --> 00:40:40,042 There's the turkey baby. 629 00:40:40,042 --> 00:40:41,250 Now a little more about that. 630 00:40:41,250 --> 00:40:44,840 This is an experiment done not too long ago, 631 00:40:44,840 --> 00:40:49,070 2001, in the Journal of Behavior, 632 00:40:49,070 --> 00:40:54,320 where some nice experiments were done on turkey chicks. 633 00:40:54,320 --> 00:40:57,810 Why did they use this particular turkey chick? 634 00:40:57,810 --> 00:41:06,770 Because it was hatched slightly below ground, 635 00:41:06,770 --> 00:41:09,680 the ground warms, and the egg hatches. 636 00:41:09,680 --> 00:41:11,310 No parents around. 637 00:41:11,310 --> 00:41:14,600 They just hatch, and the eggs are deposited separately, 638 00:41:14,600 --> 00:41:18,660 so there's no siblings around, either. 639 00:41:18,660 --> 00:41:22,600 So they're not exposed to any social cues that 640 00:41:22,600 --> 00:41:25,814 could teach them anything about predators. 641 00:41:25,814 --> 00:41:27,980 So they're going to be able to escape from predators 642 00:41:27,980 --> 00:41:33,100 when they're first hatched, and the response has to be innate. 643 00:41:33,100 --> 00:41:35,490 And that's why they picked this little chick. 644 00:41:39,400 --> 00:41:43,000 They live solitarily, of course, except when they need to mate. 645 00:41:45,650 --> 00:41:49,490 They kept them in a large outdoor aviary, 646 00:41:49,490 --> 00:41:54,930 set in a natural rainforest habitat, similar to where 647 00:41:54,930 --> 00:41:56,820 they would normally be found. 648 00:41:56,820 --> 00:41:59,680 Now in these graphs, each black bar 649 00:41:59,680 --> 00:42:07,240 shows the amount of a certain kind of behavior they saw. 650 00:42:07,240 --> 00:42:12,890 In this case, running behavior. 651 00:42:12,890 --> 00:42:15,230 So the animal is running in response 652 00:42:15,230 --> 00:42:17,610 to the stimuli listed here. 653 00:42:17,610 --> 00:42:19,890 The first bars there, are response 654 00:42:19,890 --> 00:42:23,980 to a live cat walking through the aviary. 655 00:42:23,980 --> 00:42:27,680 The second one to a live dog. 656 00:42:27,680 --> 00:42:31,180 The third one to a snake model. 657 00:42:31,180 --> 00:42:32,850 They didn't use a live snake, but they 658 00:42:32,850 --> 00:42:34,550 had a model of a snake. 659 00:42:34,550 --> 00:42:40,480 OK and as models of snakes can look exactly like a snake. 660 00:42:40,480 --> 00:42:45,130 Those are the three stimuli that caused the most running. 661 00:42:45,130 --> 00:42:50,010 The stimuli that corresponded to a model of a raptor, 662 00:42:50,010 --> 00:42:54,720 so it was a hawk model, looked like a hawk shape gliding 663 00:42:54,720 --> 00:42:58,180 overhead, didn't cause the running. 664 00:42:58,180 --> 00:43:01,930 What it did what cause was the second response here, 665 00:43:01,930 --> 00:43:03,330 crouching. 666 00:43:03,330 --> 00:43:06,870 More crouching in response to that overhead stimulus 667 00:43:06,870 --> 00:43:12,650 than any of the other stimuli. 668 00:43:12,650 --> 00:43:15,120 A little more to cats than to dogs, 669 00:43:15,120 --> 00:43:17,420 but mostly to the raptors. 670 00:43:17,420 --> 00:43:21,610 But now notice another-- oh, this one here, 671 00:43:21,610 --> 00:43:24,760 when they suddenly appear very vigilant, with their head up, 672 00:43:24,760 --> 00:43:27,450 and the search mostly with their eyes. 673 00:43:27,450 --> 00:43:34,530 That response was elicited most by recordings 674 00:43:34,530 --> 00:43:41,790 not of turkey sounds, but of alarm calls of song birds 675 00:43:41,790 --> 00:43:45,070 that live in that forest. 676 00:43:45,070 --> 00:43:48,670 Indicating that these birds, as soon as they're hatched, 677 00:43:48,670 --> 00:43:53,420 respond to those alarms calls. 678 00:43:53,420 --> 00:43:55,670 Not to turkey calls, but to alarm calls 679 00:43:55,670 --> 00:43:57,710 of other birds that live in the same place. 680 00:44:00,280 --> 00:44:04,650 And they're responding mostly by that vigilance behavior. 681 00:44:04,650 --> 00:44:10,570 What they're looking for, of course, is predators. 682 00:44:10,570 --> 00:44:13,960 But now, there's a black bar and a white bar. 683 00:44:13,960 --> 00:44:17,020 The black bar is to the live cat and mouse, 684 00:44:17,020 --> 00:44:19,350 or their realistic models. 685 00:44:19,350 --> 00:44:24,430 The white bars are the response to control stimuli. 686 00:44:24,430 --> 00:44:27,590 The control stimuli were, in the case 687 00:44:27,590 --> 00:44:34,450 of the cat, dog, and the raptor, they're just cardboard boxes. 688 00:44:34,450 --> 00:44:37,550 They colored the cardboard boxes, 689 00:44:37,550 --> 00:44:40,050 so they controlled for the color, 690 00:44:40,050 --> 00:44:42,770 but not details and shape. 691 00:44:42,770 --> 00:44:44,540 And you can see they're usually respond 692 00:44:44,540 --> 00:44:46,780 the same way to the boxes. 693 00:44:46,780 --> 00:44:49,600 In the case of the snake, they used just a simple cardboard 694 00:44:49,600 --> 00:44:51,160 cylinder. 695 00:44:51,160 --> 00:44:53,520 That was very effective. 696 00:44:53,520 --> 00:44:56,680 But there were exceptions to that. 697 00:44:56,680 --> 00:44:58,760 In other words, the only thing about this one 698 00:44:58,760 --> 00:45:03,270 that made it a raptor was that it was up here. 699 00:45:03,270 --> 00:45:06,670 And it was about the right speed of movement, 700 00:45:06,670 --> 00:45:08,670 and the right size. 701 00:45:08,670 --> 00:45:10,490 That's all that was required. 702 00:45:10,490 --> 00:45:14,540 But notice here, this is the recordings of sound. 703 00:45:14,540 --> 00:45:17,820 Here there was a significant difference 704 00:45:17,820 --> 00:45:22,740 between the experimental sounds, the recording the actual alarm 705 00:45:22,740 --> 00:45:25,070 calls, and just quite white noise, 706 00:45:25,070 --> 00:45:27,150 because white noise was the control here. 707 00:45:27,150 --> 00:45:32,650 So there they have a specific response, specific differences. 708 00:45:32,650 --> 00:45:37,580 And perhaps in the case of the raptor, 709 00:45:37,580 --> 00:45:40,470 there, as I mentioned once before in the class, 710 00:45:40,470 --> 00:45:45,190 there is some evidence that they have 711 00:45:45,190 --> 00:45:47,170 some specificity of response. 712 00:45:47,170 --> 00:45:49,990 But you can see here, they couldn't confirm it. 713 00:45:49,990 --> 00:45:53,890 That it had anything to do with the hawk shape. 714 00:45:53,890 --> 00:45:57,410 That doesn't mean that later on it doesn't. 715 00:45:57,410 --> 00:45:59,730 Because they can habituate to other shapes, 716 00:45:59,730 --> 00:46:05,440 and not to the hawk, if their experience 717 00:46:05,440 --> 00:46:08,100 is teaching them something else. 718 00:46:08,100 --> 00:46:11,000 But it's interesting how nonspecific 719 00:46:11,000 --> 00:46:13,910 some of these fixed actions, the key stimuli can be. 720 00:46:13,910 --> 00:46:16,800 They're very, very simple. 721 00:46:16,800 --> 00:46:20,090 What we see as the hawk, what they see as just something 722 00:46:20,090 --> 00:46:22,800 up there that's about the size a hawk, and moving 723 00:46:22,800 --> 00:46:23,630 in a certain way. 724 00:46:26,740 --> 00:46:31,390 Do humans show maladaptive responses to key stimuli, too? 725 00:46:31,390 --> 00:46:33,420 They certainly do. 726 00:46:33,420 --> 00:46:35,970 We eat too much sugar, we eat high-fat foods 727 00:46:35,970 --> 00:46:38,260 because it tastes better. 728 00:46:38,260 --> 00:46:42,620 And the restaurants always add extra sugar and fat. 729 00:46:42,620 --> 00:46:46,090 Restaurants are a horror for diabetics. 730 00:46:46,090 --> 00:46:47,620 I've learned that. 731 00:46:47,620 --> 00:46:49,412 I always have trouble with my blood sugar 732 00:46:49,412 --> 00:46:50,620 after eating at a restaurant. 733 00:46:50,620 --> 00:46:54,800 So I choose my restaurants very, very carefully. 734 00:46:54,800 --> 00:46:59,670 And generally won't go to them at all. 735 00:46:59,670 --> 00:47:01,740 What about other things? 736 00:47:01,740 --> 00:47:03,910 I picked this quote from the internet, 737 00:47:03,910 --> 00:47:07,480 and I found this just last year. 738 00:47:07,480 --> 00:47:09,550 "Like all animals, humans have instincts. 739 00:47:09,550 --> 00:47:13,740 Genetically hardwired behaviors that enhance our ability 740 00:47:13,740 --> 00:47:16,880 to cope with vital, environmental contingencies. 741 00:47:16,880 --> 00:47:21,410 Our innate fear of snakes is an example. 742 00:47:21,410 --> 00:47:24,310 Other instincts, including denial, revenge, 743 00:47:24,310 --> 00:47:27,740 tribal loyalty, greed, and our urge to procreate now 744 00:47:27,740 --> 00:47:30,280 threaten our very existence." 745 00:47:30,280 --> 00:47:31,730 In other words, it's important we 746 00:47:31,730 --> 00:47:35,743 come to understand our own fixed action patterns. 747 00:47:42,769 --> 00:47:44,310 Let's talk about one more thing here. 748 00:47:44,310 --> 00:47:48,580 Lorenz's discussion of the transposability of key stimuli. 749 00:47:48,580 --> 00:47:52,850 All he means is that animals are responding, 750 00:47:52,850 --> 00:47:57,300 not the exact size of the stimuli usually doesn't matter, 751 00:47:57,300 --> 00:48:00,070 but if it's the configuration at all-- this 752 00:48:00,070 --> 00:48:03,635 is unlike in most turkeys where the size and movement where 753 00:48:03,635 --> 00:48:05,210 it seemed to be critical. 754 00:48:05,210 --> 00:48:09,730 But in most cases, it's the relationship between stimuli. 755 00:48:09,730 --> 00:48:13,160 Just like the relationship between sounds in a song-- 756 00:48:13,160 --> 00:48:16,380 we recognize the song even though the pitch may 757 00:48:16,380 --> 00:48:19,160 vary a lot, and the loudness may vary a lot, 758 00:48:19,160 --> 00:48:20,540 we can still recognize it. 759 00:48:25,150 --> 00:48:26,900 And you can use dummy stimuli. 760 00:48:26,900 --> 00:48:29,180 I just drew some of these. 761 00:48:29,180 --> 00:48:33,190 Most little birds, nesting thrushes, 762 00:48:33,190 --> 00:48:36,370 they respond to any stimulus that's 763 00:48:36,370 --> 00:48:39,410 even remotely similar to a bird. 764 00:48:39,410 --> 00:48:42,120 All it has to have is a top part that's 765 00:48:42,120 --> 00:48:44,200 about one third the size the bottom part, 766 00:48:44,200 --> 00:48:45,890 and they will show gaping. 767 00:48:45,890 --> 00:48:47,740 That's about all they require. 768 00:48:47,740 --> 00:48:49,540 Seems very stupid, what they're doing. 769 00:48:49,540 --> 00:48:51,290 But that's all that's required. 770 00:48:51,290 --> 00:48:53,609 And if you have two sticks like this, 771 00:48:53,609 --> 00:48:55,150 that are presented like this, they'll 772 00:48:55,150 --> 00:48:56,780 always respond to the upper one. 773 00:48:56,780 --> 00:48:59,050 If they're presented, one's much closer, 774 00:48:59,050 --> 00:49:01,860 than they will respond-- if it's presented horizontally, 775 00:49:01,860 --> 00:49:06,800 anyway-- they'll respond to the nearer one. 776 00:49:06,800 --> 00:49:09,200 But if they're presented like this, 777 00:49:09,200 --> 00:49:11,160 even though this is nearer, they'll 778 00:49:11,160 --> 00:49:13,130 still go for the upper one. 779 00:49:13,130 --> 00:49:17,650 Because it's just a matter probabilities. 780 00:49:17,650 --> 00:49:20,000 What they're likely to encounter in that nest 781 00:49:20,000 --> 00:49:23,010 when they're feeding. 782 00:49:23,010 --> 00:49:27,540 And these simple stimulus properties 783 00:49:27,540 --> 00:49:30,230 have been exploited by other birds. 784 00:49:30,230 --> 00:49:32,760 Birds like the cuckoo that lay their nests 785 00:49:32,760 --> 00:49:35,780 in other bird's nests. 786 00:49:35,780 --> 00:49:41,160 Because those other birds respond to the egg, in fact 787 00:49:41,160 --> 00:49:46,050 if it's a little larger, they might respond better to it. 788 00:49:46,050 --> 00:49:53,550 Often the eggs, depending on the parasitic bird, 789 00:49:53,550 --> 00:49:54,780 resembles their egg. 790 00:49:54,780 --> 00:49:58,090 In the case of the cuckoo, it doesn't always. 791 00:49:58,090 --> 00:49:59,990 In the case of the whydah bird, the egg 792 00:49:59,990 --> 00:50:03,580 mimics the egg of the species there. 793 00:50:03,580 --> 00:50:06,670 They're fooling, and getting to raise their young. 794 00:50:06,670 --> 00:50:11,750 And even their babies look like the other species for awhile. 795 00:50:11,750 --> 00:50:14,610 Whydahs are much more innocuous, in that 796 00:50:14,610 --> 00:50:17,480 they don't destroy the other birds in the next. 797 00:50:17,480 --> 00:50:19,530 But the cuckoo is horrible. 798 00:50:19,530 --> 00:50:23,300 It puts its egg in there, and it hatches, at least one 799 00:50:23,300 --> 00:50:26,132 of those eggs won't even survive. 800 00:50:26,132 --> 00:50:28,240 The chick won't even survive. 801 00:50:28,240 --> 00:50:32,000 In many cases, no other little birds will survive. 802 00:50:32,000 --> 00:50:33,730 Just the cuckoo. 803 00:50:33,730 --> 00:50:34,840 So why did they do it? 804 00:50:39,600 --> 00:50:42,540 Lorenz says it's their vice. 805 00:50:42,540 --> 00:50:44,200 You know a vice, you're following 806 00:50:44,200 --> 00:50:47,190 an instinct that's bad for you. 807 00:50:47,190 --> 00:50:49,200 He says the vice of these birds is 808 00:50:49,200 --> 00:50:52,180 they respond to the gaping response of these-- Look 809 00:50:52,180 --> 00:50:54,470 at the gape here of the cuckoo. 810 00:50:54,470 --> 00:50:57,510 There's this enormous chick with this huge gape, 811 00:50:57,510 --> 00:51:01,360 and there's the reed warbler feeding him. 812 00:51:01,360 --> 00:51:02,070 That's his vice. 813 00:51:02,070 --> 00:51:04,640 He can't resist. 814 00:51:04,640 --> 00:51:08,180 So think about, why don't the birds 815 00:51:08,180 --> 00:51:12,970 evolve some way to avoid this being taken advantage of? 816 00:51:12,970 --> 00:51:16,150 And having their own reproduction go down? 817 00:51:16,150 --> 00:51:19,520 Because they're raising other birds' chicks. 818 00:51:19,520 --> 00:51:22,350 We'll talk about that next time.