1 00:00:00,370 --> 00:00:02,790 The following content is provided under a Creative 2 00:00:02,790 --> 00:00:04,210 Commons license. 3 00:00:04,210 --> 00:00:07,240 Your support will help MIT OpenCourseWare continue to 4 00:00:07,240 --> 00:00:10,900 offer high quality educational resources for free. 5 00:00:10,900 --> 00:00:13,790 To make a donation or view additional materials from 6 00:00:13,790 --> 00:00:19,620 hundreds of MIT courses, visit MIT OpenCourseWare at 7 00:00:19,620 --> 00:00:20,870 ocw.mit.edu. 8 00:00:34,340 --> 00:00:35,670 PROFESSOR: Sometimes psychologists like to talk 9 00:00:35,670 --> 00:00:40,570 about two aspects of our mind, the hot and the cool. 10 00:00:40,570 --> 00:00:44,290 So the cool parts we've been talking about recently, 11 00:00:44,290 --> 00:00:47,970 thinking parts, like language, thought, things related to 12 00:00:47,970 --> 00:00:52,540 intelligence, problem solving, the rational aspects of the 13 00:00:52,540 --> 00:00:53,630 human mind. 14 00:00:53,630 --> 00:00:56,360 And today we're going to focus on maybe the hottest of the 15 00:00:56,360 --> 00:01:01,240 hot, the emotions that we feel and that color our lives in 16 00:01:01,240 --> 00:01:06,120 terms of intensity and arousal and what matters to us. 17 00:01:06,120 --> 00:01:09,590 And so we'll talk a little bit about, just very briefly about 18 00:01:09,590 --> 00:01:11,410 a thumbnail history of the study of emotion, the 19 00:01:11,410 --> 00:01:15,160 scientific study of emotion, ideas about how to define it, 20 00:01:15,160 --> 00:01:18,430 a few models of emotion, how emotion might work, some big 21 00:01:18,430 --> 00:01:22,440 questions about things like is emotion universal, does it 22 00:01:22,440 --> 00:01:24,990 correlate to bodily feelings? 23 00:01:24,990 --> 00:01:26,160 Why do we have emotion? 24 00:01:26,160 --> 00:01:29,060 And then things about the brain basis of emotions. 25 00:01:29,060 --> 00:01:33,010 So we have a huge number of words, by one count about 550 26 00:01:33,010 --> 00:01:36,860 words, that describe the feelings we have, 27 00:01:36,860 --> 00:01:38,870 the emotions we have. 28 00:01:38,870 --> 00:01:41,740 And there's a lot of overlap conceptually among them, but 29 00:01:41,740 --> 00:01:45,260 we have so many words because we think that, we feel that 30 00:01:45,260 --> 00:01:48,280 from our daily lives, the feelings and emotions that we 31 00:01:48,280 --> 00:01:51,950 have are such a big part of our human existence, how we 32 00:01:51,950 --> 00:01:55,640 relate to other people, how we feel when we're by ourselves. 33 00:01:55,640 --> 00:01:58,790 Emotions are just a big, big part of how we 34 00:01:58,790 --> 00:02:01,280 go about our lives. 35 00:02:01,280 --> 00:02:05,090 And they're readily apparent to us everywhere we look on 36 00:02:05,090 --> 00:02:06,150 the faces of others. 37 00:02:06,150 --> 00:02:09,210 Positive emotions, negative emotions, fearful emotions, 38 00:02:09,210 --> 00:02:13,740 you see them around you all the time. 39 00:02:13,740 --> 00:02:17,270 In psychology, a lot of ideas about formulating the field go 40 00:02:17,270 --> 00:02:19,190 back to William James, who worked at Harvard, who 41 00:02:19,190 --> 00:02:22,260 articulated in many ways, in language that's still relevant 42 00:02:22,260 --> 00:02:26,030 to this day, the basic ideas, the basic things about being a 43 00:02:26,030 --> 00:02:28,650 human that one wants to understand out of a 44 00:02:28,650 --> 00:02:29,840 psychology. 45 00:02:29,840 --> 00:02:32,630 And he wrote about emotion this way, "If you can conceive 46 00:02:32,630 --> 00:02:35,430 of yourself suddenly stripped of all the emotion with which 47 00:02:35,430 --> 00:02:38,810 our world now inspires you, no one portion of the universe 48 00:02:38,810 --> 00:02:40,940 would have more important characteristics beyond 49 00:02:40,940 --> 00:02:43,460 another; and the whole character of its things and 50 00:02:43,460 --> 00:02:45,770 series of events would be without significance, 51 00:02:45,770 --> 00:02:48,960 character, expression, or perspective." That what we 52 00:02:48,960 --> 00:02:53,710 fear, what we desire, what we enjoy, what we find 53 00:02:53,710 --> 00:02:54,250 disgusting-- 54 00:02:54,250 --> 00:02:56,710 we'll talk a little bit about disgust today-- that all those 55 00:02:56,710 --> 00:02:59,950 things tell us what's important and whether it's to 56 00:02:59,950 --> 00:03:04,070 be avoided or approached, enjoyed or loathed. 57 00:03:04,070 --> 00:03:06,540 And so people have thought about emotions. 58 00:03:06,540 --> 00:03:08,740 You could pick a million different cultural directions. 59 00:03:08,740 --> 00:03:11,330 Here's a picture from Greek philosophy. 60 00:03:11,330 --> 00:03:12,670 But you could pick practically every 61 00:03:12,670 --> 00:03:13,770 culture around the world. 62 00:03:13,770 --> 00:03:16,350 You can't be a human and not think about the 63 00:03:16,350 --> 00:03:18,560 feelings you have. 64 00:03:18,560 --> 00:03:22,690 But kind of strikingly in terms of research, for a very, 65 00:03:22,690 --> 00:03:26,150 very long time compared to language or thinking or many 66 00:03:26,150 --> 00:03:30,640 topics, people didn't study emotion because it seemed hard 67 00:03:30,640 --> 00:03:33,060 to study scientifically. 68 00:03:33,060 --> 00:03:35,210 And it's still harder to study scientifically in many ways, I 69 00:03:35,210 --> 00:03:37,480 think, than cognition. 70 00:03:37,480 --> 00:03:40,220 But there's been tremendous progress in bringing 71 00:03:40,220 --> 00:03:42,760 scientific approaches to understanding something about 72 00:03:42,760 --> 00:03:47,860 emotions in you and I. And like many things, it was 73 00:03:47,860 --> 00:03:50,400 reinvigorated around the Renaissance and the mystery of 74 00:03:50,400 --> 00:03:53,000 Mona Lisa's smile. 75 00:03:53,000 --> 00:03:55,460 And now there's entire journals and conferences and 76 00:03:55,460 --> 00:03:57,420 organizations of scientific psychology 77 00:03:57,420 --> 00:03:58,730 devoted to study emotion. 78 00:03:58,730 --> 00:04:00,210 It's a big part of our lives. 79 00:04:00,210 --> 00:04:02,310 You would think in the study of the human mind and brain it 80 00:04:02,310 --> 00:04:03,690 would be a big endeavor. 81 00:04:03,690 --> 00:04:04,990 And it is now. 82 00:04:04,990 --> 00:04:09,430 But that wouldn't have been true even 20 years ago. 83 00:04:09,430 --> 00:04:13,340 How might we define emotion just to sort of have some 84 00:04:13,340 --> 00:04:13,920 boundaries? 85 00:04:13,920 --> 00:04:16,200 So we could say that emotions are biologically-based 86 00:04:16,200 --> 00:04:18,010 responses to situations that are seen 87 00:04:18,010 --> 00:04:19,579 as personally relevant. 88 00:04:19,579 --> 00:04:21,709 They are shaped by learning and usually involves changes 89 00:04:21,709 --> 00:04:23,400 in peripheral physiology. 90 00:04:23,400 --> 00:04:25,430 Your hands are trembling or things like that. 91 00:04:25,430 --> 00:04:26,700 Your heart is pounding. 92 00:04:26,700 --> 00:04:30,170 Expressive behavior, the intonation with which you 93 00:04:30,170 --> 00:04:33,740 speak, the facial expression that you 94 00:04:33,740 --> 00:04:35,100 have or see in others. 95 00:04:35,100 --> 00:04:36,650 And subjective experience. 96 00:04:36,650 --> 00:04:39,690 The emotions you have go with what you feel is going on 97 00:04:39,690 --> 00:04:41,780 inside you. 98 00:04:41,780 --> 00:04:44,280 Research has tried to distinguish between moods and 99 00:04:44,280 --> 00:04:47,700 emotions, and talk about moods as diffuse, long-lasting 100 00:04:47,700 --> 00:04:48,670 emotional states. 101 00:04:48,670 --> 00:04:52,150 When you're in a funk or a positive mood over days, 102 00:04:52,150 --> 00:04:55,480 weeks, months, that's not what we're going 103 00:04:55,480 --> 00:04:56,250 to talk about today. 104 00:04:56,250 --> 00:04:58,160 That's interesting and important also. 105 00:04:58,160 --> 00:04:59,640 We're going to talk about emotions, which are very 106 00:04:59,640 --> 00:05:03,110 punctate, immediate responses to situations, to a specific 107 00:05:03,110 --> 00:05:06,910 thing or a specific stress or a specific element of your 108 00:05:06,910 --> 00:05:11,420 environment, an immediate, strong response. 109 00:05:11,420 --> 00:05:13,450 And within that, one more distinction has turned out to 110 00:05:13,450 --> 00:05:16,050 be useful for thinking about emotions between two 111 00:05:16,050 --> 00:05:18,920 dimensions, arousal, or you could call it 112 00:05:18,920 --> 00:05:21,670 intensity, and valence. 113 00:05:21,670 --> 00:05:24,200 Arousal means things that are exciting, intense, if they're 114 00:05:24,200 --> 00:05:26,870 high arousal, or calm or lethargic 115 00:05:26,870 --> 00:05:28,320 if they're low arousal. 116 00:05:28,320 --> 00:05:30,840 Valence refers to whether it's a positive thing that makes 117 00:05:30,840 --> 00:05:35,500 you elated or contented, negative sad or gloomy. 118 00:05:35,500 --> 00:05:37,060 And you can already see, for example, 119 00:05:37,060 --> 00:05:38,720 take positive valence. 120 00:05:38,720 --> 00:05:41,150 Elated is high arousal. 121 00:05:41,150 --> 00:05:44,220 Contented, ah, that's low arousal. 122 00:05:44,220 --> 00:05:46,900 They're both positive, but they're kind of different. 123 00:05:46,900 --> 00:05:48,790 So is calm versus lethargic. 124 00:05:48,790 --> 00:05:50,520 Being calm can be sometimes good. 125 00:05:50,520 --> 00:05:54,150 Feeling really slow, really lethargic, also is low 126 00:05:54,150 --> 00:05:57,570 arousal, but it's usually not a desirable low arousal. 127 00:05:57,570 --> 00:05:59,580 And so people think that they can take basically these two 128 00:05:59,580 --> 00:06:02,850 dimensions, valence and arousal, and use it as a 129 00:06:02,850 --> 00:06:06,080 useful way to say something like calm is here. 130 00:06:06,080 --> 00:06:08,970 It's a little bit positive and it's low 131 00:06:08,970 --> 00:06:10,550 on the arousal dimension. 132 00:06:10,550 --> 00:06:11,690 Excited is up here. 133 00:06:11,690 --> 00:06:14,070 It's a positive valence. 134 00:06:14,070 --> 00:06:18,020 Different things, gloomy is negative and it's fairly 135 00:06:18,020 --> 00:06:21,280 intense feeling, as opposed to merely lethargic. 136 00:06:21,280 --> 00:06:24,170 These two dimensions can cover a big sense of the life of 137 00:06:24,170 --> 00:06:28,610 emotions that inhabit us. 138 00:06:28,610 --> 00:06:31,430 And a huge question, and one that's brutally hard to 139 00:06:31,430 --> 00:06:33,865 satisfy in some deep scientific way, of course, is 140 00:06:33,865 --> 00:06:35,540 it restricted to humans? 141 00:06:35,540 --> 00:06:40,110 So if you hang around pets and animals in various 142 00:06:40,110 --> 00:06:42,660 circumstances, you can't help but feel they have emotions. 143 00:06:42,660 --> 00:06:44,890 It's just very hard for us to ask them to fill out 144 00:06:44,890 --> 00:06:47,900 questionnaires telling us their emotions. 145 00:06:47,900 --> 00:06:50,250 Here's a chimp that has lost its mother recently. 146 00:06:53,660 --> 00:06:57,034 Here's a dog going out for a good old night. 147 00:06:57,034 --> 00:06:59,330 Here's an armadillo going, whee! 148 00:06:59,330 --> 00:07:02,520 It looks pretty aroused. 149 00:07:02,520 --> 00:07:05,480 We don't know how much of this in some cases is us reading 150 00:07:05,480 --> 00:07:09,060 human feelings into their expressions, how much of that 151 00:07:09,060 --> 00:07:11,200 is them feeling the same as we do. 152 00:07:11,200 --> 00:07:14,650 There's a lot of sense, obviously, that many species 153 00:07:14,650 --> 00:07:15,990 have feelings as well as humans. 154 00:07:15,990 --> 00:07:18,810 We'll focus just on humans today. 155 00:07:18,810 --> 00:07:20,140 And the other thing that's important is 156 00:07:20,140 --> 00:07:21,020 they're shaped by learning. 157 00:07:21,020 --> 00:07:23,450 What that means is many different things, but for 158 00:07:23,450 --> 00:07:27,210 example, they can vary from one culture to another in 159 00:07:27,210 --> 00:07:29,200 certain ways. 160 00:07:29,200 --> 00:07:33,520 And here's one example of a movie that's bringing tears to 161 00:07:33,520 --> 00:07:35,270 everybody's eyes, except this person who 162 00:07:35,270 --> 00:07:38,380 finds it utterly hilarious. 163 00:07:38,380 --> 00:07:39,870 If you work in emotion research, I can 164 00:07:39,870 --> 00:07:41,750 tell you you get that. 165 00:07:41,750 --> 00:07:43,880 I worked a little bit on that. 166 00:07:43,880 --> 00:07:45,420 You show some really horrible pictures to everybody. 167 00:07:45,420 --> 00:07:46,910 They go, oh, horrible, horrible, horrible. 168 00:07:46,910 --> 00:07:48,190 And somebody else starts laughing. 169 00:07:48,190 --> 00:07:48,920 It's like horror movies. 170 00:07:48,920 --> 00:07:51,540 Have you've been around horror movies where some people are 171 00:07:51,540 --> 00:07:53,800 really scared out of their seats and very worried about 172 00:07:53,800 --> 00:07:55,010 the characters and other people think 173 00:07:55,010 --> 00:07:56,110 it's all pretty funny? 174 00:07:56,110 --> 00:07:57,930 So that's your prospective. 175 00:07:57,930 --> 00:08:02,730 It's not an automatic response to many situations. 176 00:08:02,730 --> 00:08:05,310 So how have people thought about the emotion you feel 177 00:08:05,310 --> 00:08:07,580 when a bear jumps out of your closet unexpectedly? 178 00:08:10,720 --> 00:08:12,540 Here's the logical one. 179 00:08:12,540 --> 00:08:13,310 Common sense. 180 00:08:13,310 --> 00:08:15,340 Bear is scary. 181 00:08:15,340 --> 00:08:16,970 You feel fearful. 182 00:08:16,970 --> 00:08:18,650 That's your subjective experience. 183 00:08:18,650 --> 00:08:20,460 And your body starts to do things like your 184 00:08:20,460 --> 00:08:21,770 heart starts to pump. 185 00:08:21,770 --> 00:08:24,290 Your sweat glands start to sweat, because 186 00:08:24,290 --> 00:08:25,390 you go, this is dangerous. 187 00:08:25,390 --> 00:08:26,110 This is scary. 188 00:08:26,110 --> 00:08:27,100 Here comes my body. 189 00:08:27,100 --> 00:08:28,370 That would be the intuitive one. 190 00:08:28,370 --> 00:08:31,770 My heart is pounding because I feel afraid. 191 00:08:31,770 --> 00:08:36,380 Interestingly, you can reverse the order and find some things 192 00:08:36,380 --> 00:08:38,780 that are better explained that way. 193 00:08:38,780 --> 00:08:41,480 It's sometimes nice, sometimes people will say, oh my gosh. 194 00:08:41,480 --> 00:08:43,659 Everything in psychology is so obvious. 195 00:08:43,659 --> 00:08:45,200 For some reason, they always say, my grandmother 196 00:08:45,200 --> 00:08:45,630 would have known it. 197 00:08:45,630 --> 00:08:47,610 I don't know why they pick that example. 198 00:08:47,610 --> 00:08:50,650 Show us something that science only can tell you. 199 00:08:50,650 --> 00:08:54,060 So here's a very clever reversal from William James 200 00:08:54,060 --> 00:08:55,780 and also Lange. 201 00:08:55,780 --> 00:08:56,730 They reversed it. 202 00:08:56,730 --> 00:09:00,860 They said that first comes the bodily response to the 203 00:09:00,860 --> 00:09:05,210 situation and second comes your mind interpreting your 204 00:09:05,210 --> 00:09:06,790 body's primary response. 205 00:09:06,790 --> 00:09:11,200 The exact opposite order of why we feel as we do. 206 00:09:11,200 --> 00:09:14,160 "We feel sorry because we cry, angry because we strike, 207 00:09:14,160 --> 00:09:17,570 afraid because we tremble, and not that we strike, cry, or 208 00:09:17,570 --> 00:09:19,660 tremble because we are sorry, angry, or fearful." He sees 209 00:09:19,660 --> 00:09:20,870 the exact opposite. 210 00:09:20,870 --> 00:09:23,770 Here it says first comes an emotion that's shaking your 211 00:09:23,770 --> 00:09:26,560 body in some way, and then comes to your mind saying, 212 00:09:26,560 --> 00:09:28,030 aha, I'm afraid-- 213 00:09:28,030 --> 00:09:29,110 pretty fast-- 214 00:09:29,110 --> 00:09:31,840 or I'm happy or whatever. 215 00:09:31,840 --> 00:09:34,150 Here's some examples, because you could think, OK, yes, you 216 00:09:34,150 --> 00:09:35,120 can cleverly reverse them. 217 00:09:35,120 --> 00:09:37,570 But is there any science to suggest that in some cases 218 00:09:37,570 --> 00:09:39,490 that relationship does reverse? 219 00:09:39,490 --> 00:09:40,360 So here's what people did. 220 00:09:40,360 --> 00:09:41,760 And I'll show you a picture for this. 221 00:09:41,760 --> 00:09:44,160 They said, how can peripheral bodily events, things on sort 222 00:09:44,160 --> 00:09:46,230 of the edge of our bodies, influence the 223 00:09:46,230 --> 00:09:48,270 emotions we feel inside? 224 00:09:48,270 --> 00:09:50,710 So they would have people do things like hold a pencil 225 00:09:50,710 --> 00:09:53,630 tightly between their teeth and-- 226 00:09:53,630 --> 00:09:55,530 look at that pencil. 227 00:09:55,530 --> 00:09:56,830 They're not told to smile. 228 00:09:56,830 --> 00:09:58,570 They're just told to keep that pencil there. 229 00:09:58,570 --> 00:10:00,100 And what does that look like? 230 00:10:00,100 --> 00:10:01,040 A smile, right? 231 00:10:01,040 --> 00:10:01,530 OK. 232 00:10:01,530 --> 00:10:04,490 You've tricked the person's face into smiling. 233 00:10:04,490 --> 00:10:05,940 And they don't even know that, necessarily. 234 00:10:05,940 --> 00:10:07,720 They're thinking, this is a weird psychology experiment 235 00:10:07,720 --> 00:10:09,750 about how long can you hold a pencil in your mouth, although 236 00:10:09,750 --> 00:10:13,240 they're going to know something more in a moment. 237 00:10:13,240 --> 00:10:16,300 Or between the lips, hold that pencil. 238 00:10:16,300 --> 00:10:18,440 Now, does this person look happy? 239 00:10:18,440 --> 00:10:18,590 No. 240 00:10:18,590 --> 00:10:20,910 A little bit not happy, right? 241 00:10:20,910 --> 00:10:22,880 OK. 242 00:10:22,880 --> 00:10:27,930 And then you have them watch a funny movie that most people 243 00:10:27,930 --> 00:10:29,250 find funny. 244 00:10:29,250 --> 00:10:31,080 And they rate how much they like it. 245 00:10:31,080 --> 00:10:36,330 And the person who had this one rates it as more enjoyable 246 00:10:36,330 --> 00:10:39,630 than the person holding a pencil this way, as if already 247 00:10:39,630 --> 00:10:43,050 having the muscles in your face moved into a position 248 00:10:43,050 --> 00:10:47,190 that typically signals happiness or laughter makes 249 00:10:47,190 --> 00:10:51,860 you feel happy inside and the funny movie is even funnier. 250 00:10:51,860 --> 00:10:55,810 Being in a somewhat neutral to negative position makes that 251 00:10:55,810 --> 00:10:58,610 same funny movie seem less funny. 252 00:10:58,610 --> 00:11:02,380 You're interpreting where your muscles are that normally go 253 00:11:02,380 --> 00:11:04,360 with one emotion or another, and that's driving your 254 00:11:04,360 --> 00:11:08,640 internal final emotion about how you feel about the movie. 255 00:11:08,640 --> 00:11:10,274 Was there a question? 256 00:11:10,274 --> 00:11:10,574 AUDIENCE: Could it require more 257 00:11:10,574 --> 00:11:11,824 concentration, or patience? 258 00:11:13,430 --> 00:11:15,340 PROFESSOR: Does one require more concentration? 259 00:11:15,340 --> 00:11:17,820 That's an excellent question, because we always like to say, 260 00:11:17,820 --> 00:11:18,690 oh, it's this thing. 261 00:11:18,690 --> 00:11:20,580 What if this is a harder thing like that? 262 00:11:20,580 --> 00:11:22,130 And so when one have to hope-- and I have to 263 00:11:22,130 --> 00:11:23,800 admit I don't know-- 264 00:11:23,800 --> 00:11:26,690 that they've controlled for things like that in some way. 265 00:11:26,690 --> 00:11:27,710 If you read the research paper, 266 00:11:27,710 --> 00:11:28,390 you'd want to be concerned. 267 00:11:28,390 --> 00:11:29,730 That's an excellent question. 268 00:11:29,730 --> 00:11:32,680 If this is just harder work than maybe you're paying less 269 00:11:32,680 --> 00:11:34,750 attention to the movie and just hanging onto that pencil. 270 00:11:34,750 --> 00:11:35,730 I don't know. 271 00:11:35,730 --> 00:11:37,360 And I have to hope they did a good job on this. 272 00:11:37,360 --> 00:11:40,390 That's an excellent question. 273 00:11:40,390 --> 00:11:42,510 And here's other ones, again, where they're trying to get 274 00:11:42,510 --> 00:11:46,260 the face to go smiley or go frowny. 275 00:11:46,260 --> 00:11:49,040 And then they just ask them, how do you feel? 276 00:11:49,040 --> 00:11:51,810 And this person will rate themselves as feeling happier 277 00:11:51,810 --> 00:11:54,280 than this person as they answer on a piece of paper in 278 00:11:54,280 --> 00:11:55,020 front of them. 279 00:11:55,020 --> 00:11:58,860 Again, they're trying to say, if I can move your peripheral 280 00:11:58,860 --> 00:12:01,010 facial expressions into-- 281 00:12:01,010 --> 00:12:04,260 your muscles into expressions, the feelings will follow from 282 00:12:04,260 --> 00:12:05,510 the expressions. 283 00:12:07,280 --> 00:12:09,050 You can also do something else, which is you can tell 284 00:12:09,050 --> 00:12:11,130 people-- so Paul Ekman, his name will come up a lot today. 285 00:12:11,130 --> 00:12:14,510 He's done a fantastic amount of the key research on this, 286 00:12:14,510 --> 00:12:17,980 making emotions into a research topic in many ways. 287 00:12:17,980 --> 00:12:20,480 What he developed is a way that he said, I'm going to 288 00:12:20,480 --> 00:12:25,300 describe objectively which muscles are in which position 289 00:12:25,300 --> 00:12:28,800 for each of six fundamental emotional expressions. 290 00:12:28,800 --> 00:12:30,260 We'll come back to those. 291 00:12:30,260 --> 00:12:33,500 So he would tell a person, raise your eyebrows and pull 292 00:12:33,500 --> 00:12:34,300 them together. 293 00:12:34,300 --> 00:12:35,620 Raise your upper eyelids. 294 00:12:35,620 --> 00:12:37,450 Now stretch your lips horizontally back 295 00:12:37,450 --> 00:12:38,430 towards your ears. 296 00:12:38,430 --> 00:12:41,650 So what he's giving this person, step by step, is 297 00:12:41,650 --> 00:12:45,750 directions that move the muscles into an expression of 298 00:12:45,750 --> 00:12:48,040 fear, by the time you end up there. 299 00:12:48,040 --> 00:12:49,860 The participant usually doesn't know that, because 300 00:12:49,860 --> 00:12:51,340 it's so weird. 301 00:12:51,340 --> 00:12:52,200 You're moving your mouth. 302 00:12:52,200 --> 00:12:52,790 You're moving-- 303 00:12:52,790 --> 00:12:54,300 it's just so weird. 304 00:12:54,300 --> 00:12:56,160 But then they can do these kinds of experiments. 305 00:12:56,160 --> 00:12:59,340 And these people will report a fearful movie as being more 306 00:12:59,340 --> 00:13:02,600 fearful than somebody who just gets to sit there or whose 307 00:13:02,600 --> 00:13:05,580 muscles are moved into a happy position. 308 00:13:05,580 --> 00:13:08,240 So all of a sudden you've got all these peripheral things 309 00:13:08,240 --> 00:13:10,770 being interpreted by our mind as a signal for what emotion 310 00:13:10,770 --> 00:13:13,140 you have, or enhancing it anyway. 311 00:13:13,140 --> 00:13:16,500 And then because any strong theory usually turns out to be 312 00:13:16,500 --> 00:13:19,980 not nearly complicated enough, you get the wishy-washy middle 313 00:13:19,980 --> 00:13:22,760 that probably covers more of the truth, which is both 314 00:13:22,760 --> 00:13:24,050 things are going on. 315 00:13:24,050 --> 00:13:26,350 Both you're having a subjective cognitive 316 00:13:26,350 --> 00:13:28,810 interpretation of your environment and a bodily 317 00:13:28,810 --> 00:13:30,680 response, maybe more in parallel than 318 00:13:30,680 --> 00:13:32,860 one driving the other. 319 00:13:32,860 --> 00:13:35,110 So again, how can peripheral bodily 320 00:13:35,110 --> 00:13:38,690 events influence emotions? 321 00:13:38,690 --> 00:13:41,570 One idea that's floated around, and probably true, is 322 00:13:41,570 --> 00:13:43,540 that the perception or thought, your mental 323 00:13:43,540 --> 00:13:46,670 interpretation of your emotion tells you the type of emotion. 324 00:13:46,670 --> 00:13:50,980 so if a bear jumps out, you can say, OK, I know 325 00:13:50,980 --> 00:13:52,150 something's pretty intense. 326 00:13:52,150 --> 00:13:55,050 And I can tell you right away it's bad. 327 00:13:55,050 --> 00:13:57,040 But if something wonderful jumps out of your closet 328 00:13:57,040 --> 00:14:00,140 unexpectedly, then you go, oh my gosh. 329 00:14:00,140 --> 00:14:03,460 I can't believe Lindsay Lohan is visiting me and I didn't 330 00:14:03,460 --> 00:14:05,170 even know it. 331 00:14:05,170 --> 00:14:10,540 Then if that is considered a good visit, that would 332 00:14:10,540 --> 00:14:12,790 influence again, the interpretation, but the 333 00:14:12,790 --> 00:14:14,720 intensity might come from the bodily parts. 334 00:14:14,720 --> 00:14:17,440 How intense it is might be signaled from that. 335 00:14:17,440 --> 00:14:20,590 So here's a couple of ways that people explore this. 336 00:14:20,590 --> 00:14:23,700 Here's a study from years ago from Schacter, where he 337 00:14:23,700 --> 00:14:25,580 injected people with adrenaline-- 338 00:14:25,580 --> 00:14:31,100 adrenaline is the neurohormone that goes with high arousal, 339 00:14:31,100 --> 00:14:33,440 it raises your heart rate-- 340 00:14:33,440 --> 00:14:34,440 or a placebo. 341 00:14:34,440 --> 00:14:37,290 So he's directly taking the chemical that we normally 342 00:14:37,290 --> 00:14:40,560 produce under higher arousal conditions. 343 00:14:40,560 --> 00:14:42,780 And the first question you might ask is, and you might be 344 00:14:42,780 --> 00:14:46,890 curious about, if somebody gave you a shot of adrenaline, 345 00:14:46,890 --> 00:14:47,610 what would happen? 346 00:14:47,610 --> 00:14:48,950 Would you like jump out of your seat and run 347 00:14:48,950 --> 00:14:49,910 laps around the room? 348 00:14:49,910 --> 00:14:51,200 What would you do? 349 00:14:51,200 --> 00:14:54,440 And surprisingly, all by itself, not very much. 350 00:14:54,440 --> 00:14:56,670 People said they feel a bit jittery, like if you've had 351 00:14:56,670 --> 00:14:59,730 maybe a little too much coffee or Red Bull-- 352 00:14:59,730 --> 00:15:00,980 is that the current?-- 353 00:15:03,500 --> 00:15:04,570 that little jittery feeling. 354 00:15:04,570 --> 00:15:07,260 But they're not like jumping up and do jumping jacks and 355 00:15:07,260 --> 00:15:10,380 one-armed push-ups and stuff like that. 356 00:15:10,380 --> 00:15:13,920 Now, having had the placebo or the adrenaline injected into 357 00:15:13,920 --> 00:15:16,950 you, and you don't know that, they show you an 358 00:15:16,950 --> 00:15:18,130 emotion-eliciting-- 359 00:15:18,130 --> 00:15:20,330 they'll show you a movie, like a horror movie. 360 00:15:20,330 --> 00:15:24,470 And the people who had the adrenaline will report more 361 00:15:24,470 --> 00:15:27,880 fear when they see the horror movie, more anger when they 362 00:15:27,880 --> 00:15:28,640 get insulted. 363 00:15:28,640 --> 00:15:31,130 That's a fun experiment when you insult them. 364 00:15:31,130 --> 00:15:33,840 I'm sure the IRB, you have to be pretty careful. 365 00:15:33,840 --> 00:15:36,370 More laughter for a comedy. 366 00:15:36,370 --> 00:15:40,860 Adrenaline seemed to amplify the intensity of the emotion. 367 00:15:40,860 --> 00:15:42,390 But the emotion was driven by the situation. 368 00:15:42,390 --> 00:15:43,150 Does that make sense? 369 00:15:43,150 --> 00:15:44,770 OK? 370 00:15:44,770 --> 00:15:47,680 But here's something quite interesting about humans, 371 00:15:47,680 --> 00:15:49,540 which is that if you told them, we've given you 372 00:15:49,540 --> 00:15:52,690 adrenaline and it usually amplifies stuff, then it 373 00:15:52,690 --> 00:15:53,850 disappeared. 374 00:15:53,850 --> 00:15:57,200 Once the person knew that, they could discount that in 375 00:15:57,200 --> 00:15:57,690 their mind. 376 00:15:57,690 --> 00:16:01,210 So it's not like adrenaline is your master, and that I must 377 00:16:01,210 --> 00:16:02,800 have twice as big a response. 378 00:16:02,800 --> 00:16:05,650 Once you knew that was in the picture, then the ratings went 379 00:16:05,650 --> 00:16:08,300 back to placebo. 380 00:16:08,300 --> 00:16:10,840 It's not that biology is destiny. 381 00:16:10,840 --> 00:16:13,080 But under normal circumstances, it seems like 382 00:16:13,080 --> 00:16:15,290 the adrenaline accentuates the intensity. 383 00:16:15,290 --> 00:16:17,170 So that would go with the possibility that peripheral 384 00:16:17,170 --> 00:16:20,630 stuff drives the intensity, peripherally injected 385 00:16:20,630 --> 00:16:22,720 adrenaline, and our mind's 386 00:16:22,720 --> 00:16:25,550 interpretation drives the content. 387 00:16:25,550 --> 00:16:30,760 Here's a sort of fun, slightly sexist experiment that in the 388 00:16:30,760 --> 00:16:33,100 end, I think, explains the following phenomenon. 389 00:16:33,100 --> 00:16:36,407 When you see famous movie stars go into a movie set, on 390 00:16:36,407 --> 00:16:39,040 set, or whatever they call it, you incredibly often hear 391 00:16:39,040 --> 00:16:41,230 about romances occurring between the leads, right? 392 00:16:41,230 --> 00:16:43,370 And there's debates about what this is just the press agent 393 00:16:43,370 --> 00:16:44,500 selling their movie or whatever. 394 00:16:44,500 --> 00:16:46,200 But you hear that all the time, right? 395 00:16:46,200 --> 00:16:46,490 OK. 396 00:16:46,490 --> 00:16:48,340 So I'm going to tell you why that happens 397 00:16:48,340 --> 00:16:50,290 when it really happens. 398 00:16:50,290 --> 00:16:51,220 I can't really tell you that. 399 00:16:51,220 --> 00:16:52,060 But I can tell you an experiment that 400 00:16:52,060 --> 00:16:53,300 might touch on that. 401 00:16:53,300 --> 00:16:54,450 So here's the experiment. 402 00:16:54,450 --> 00:16:56,120 This was done by Dutton and Aron in 403 00:16:56,120 --> 00:16:57,770 North Vancouver, Canada. 404 00:16:57,770 --> 00:16:59,720 And they did the experiment in an area where there were two 405 00:16:59,720 --> 00:17:03,500 bridges not right next to each other, pretty near each other. 406 00:17:03,500 --> 00:17:07,170 One was a flimsy suspension bridge, five feet wide, 407 00:17:07,170 --> 00:17:11,200 swaying and wobbling 320 feet over jagged 408 00:17:11,200 --> 00:17:12,880 boulders and river rapids. 409 00:17:12,880 --> 00:17:15,750 So you have to imagine Indiana Jones, OK? 410 00:17:15,750 --> 00:17:16,960 And you come to this bridge and you're 411 00:17:16,960 --> 00:17:18,900 going, I don't know. 412 00:17:18,900 --> 00:17:19,750 OK. 413 00:17:19,750 --> 00:17:23,089 The other one, upstream, same river, same Canadian district. 414 00:17:23,089 --> 00:17:25,030 There's a steady, low, broad bridge. 415 00:17:25,030 --> 00:17:26,520 No problem at all. 416 00:17:26,520 --> 00:17:28,670 You could drive your car over that, no problem. 417 00:17:28,670 --> 00:17:31,290 Two bridges over the same waters, one 418 00:17:31,290 --> 00:17:34,900 seeming scary, one not. 419 00:17:34,900 --> 00:17:37,390 Then what they did is in the middle of each bridge they 420 00:17:37,390 --> 00:17:40,210 placed an attractive, in this case female, confederate. 421 00:17:40,210 --> 00:17:42,240 Maybe somebody's done the reverse gender experiment. 422 00:17:42,240 --> 00:17:43,560 I don't know. 423 00:17:43,560 --> 00:17:47,110 Anyway, as men walk across the bridge, they ask them to fill 424 00:17:47,110 --> 00:17:51,230 out a questionnaire, some boring questionnaire. 425 00:17:51,230 --> 00:17:53,940 And they casually mentioned that if that person, as they 426 00:17:53,940 --> 00:17:57,670 finish the questionnaire, has more questions, he can call 427 00:17:57,670 --> 00:17:59,670 the woman providing the questionnaire at home. 428 00:17:59,670 --> 00:18:03,060 And she provides him her home number. 429 00:18:03,060 --> 00:18:07,290 And the measure that they have is how many phone calls go 430 00:18:07,290 --> 00:18:12,180 from the male subjects to the female experimenter at home. 431 00:18:12,180 --> 00:18:14,230 And they're betting that it's not really scientific 432 00:18:14,230 --> 00:18:16,880 curiosity that's driving a lot of the phone calling. 433 00:18:16,880 --> 00:18:18,550 But here's what they actually find. 434 00:18:18,550 --> 00:18:22,300 More males will call that female at home if they were on 435 00:18:22,300 --> 00:18:25,930 the dangerous bridge than on the safe bridge. 436 00:18:25,930 --> 00:18:27,220 That's the actual finding. 437 00:18:27,220 --> 00:18:30,000 And the interpretation is this, the dangerous bridge, 438 00:18:30,000 --> 00:18:33,520 because of the true feeling of danger, produces high arousal, 439 00:18:33,520 --> 00:18:35,350 increased adrenalin. 440 00:18:35,350 --> 00:18:38,980 And that's misinterpreted, if you want to call it that, by 441 00:18:38,980 --> 00:18:42,940 the male because he thinks now he's super-attracted to that 442 00:18:42,940 --> 00:18:45,910 woman because of the swaying bridge. 443 00:18:45,910 --> 00:18:50,770 Another reason to take somebody you want to win over, 444 00:18:50,770 --> 00:18:54,370 whatever the gender situation is, a really scary roller 445 00:18:54,370 --> 00:18:57,290 coaster ride is highly recommended together with that 446 00:18:57,290 --> 00:19:01,480 warm beverage, as long as it doesn't spill on them. 447 00:19:01,480 --> 00:19:03,550 I'm making you too powerful to control people. 448 00:19:06,730 --> 00:19:09,300 Again, the arousal of the bridge has been misinterpreted 449 00:19:09,300 --> 00:19:12,030 by that person as an intense attraction to that woman. 450 00:19:12,030 --> 00:19:14,230 And you could imagine making movies are probably high 451 00:19:14,230 --> 00:19:17,220 arousal exciting situations, and that would promote 452 00:19:17,220 --> 00:19:20,310 romantic relations and high intense situations that might 453 00:19:20,310 --> 00:19:21,030 not otherwise occur. 454 00:19:21,030 --> 00:19:21,280 Yes? 455 00:19:21,280 --> 00:19:24,140 AUDIENCE: [INAUDIBLE]? 456 00:19:24,140 --> 00:19:25,990 They had to randomly assign them to one bridge or the 457 00:19:25,990 --> 00:19:28,290 other, you would hope. 458 00:19:28,290 --> 00:19:30,140 I can tell you there's been a bunch of other experiments 459 00:19:30,140 --> 00:19:31,250 sort of like this. 460 00:19:31,250 --> 00:19:33,300 This is the most what you could call ecological, silly, 461 00:19:33,300 --> 00:19:35,830 or sexist, you could figure. 462 00:19:35,830 --> 00:19:38,470 But they all go with this idea that if you're in a high 463 00:19:38,470 --> 00:19:41,840 arousal situation, you sort of move over that arousal into 464 00:19:41,840 --> 00:19:45,070 whatever it is you're encoding. 465 00:19:45,070 --> 00:19:46,830 Does that make sense? 466 00:19:46,830 --> 00:19:48,850 And in this case, because you're creating an interaction 467 00:19:48,850 --> 00:19:51,760 between a man and woman, it's promoting this probability of 468 00:19:51,760 --> 00:19:53,890 a sense of romance in the male. 469 00:19:53,890 --> 00:19:54,910 Is that OK? 470 00:19:54,910 --> 00:19:56,130 But it could be any situation. 471 00:19:56,130 --> 00:19:58,220 The arousal will make it-- if it's something, it can make 472 00:19:58,220 --> 00:19:59,210 you feel worse about it. 473 00:19:59,210 --> 00:20:00,460 AUDIENCE: [INAUDIBLE]? 474 00:20:03,840 --> 00:20:04,380 PROFESSOR: Ah. 475 00:20:04,380 --> 00:20:05,650 Totally excellent question. 476 00:20:05,650 --> 00:20:06,900 You're asking awesome questions. 477 00:20:10,570 --> 00:20:12,560 I have to assume-- and I should 478 00:20:12,560 --> 00:20:13,590 know this, but I don't-- 479 00:20:13,590 --> 00:20:14,530 that they weren't. 480 00:20:14,530 --> 00:20:18,120 Yes, because if you had males self-selecting, you had some 481 00:20:18,120 --> 00:20:20,710 males running to the danger bridge, drawn to danger, and 482 00:20:20,710 --> 00:20:24,060 others saying, oh, please give me a safe road, is that the 483 00:20:24,060 --> 00:20:24,370 real difference. 484 00:20:24,370 --> 00:20:26,120 So you have to presume they did something to 485 00:20:26,120 --> 00:20:27,020 control that, yes. 486 00:20:27,020 --> 00:20:28,270 Excellent question. 487 00:20:31,460 --> 00:20:35,480 The current view is something like that there's two factors, 488 00:20:35,480 --> 00:20:36,820 that there's both. 489 00:20:36,820 --> 00:20:39,060 A bodily response that happens pretty fast, pretty 490 00:20:39,060 --> 00:20:40,470 automatically, pretty unconsciously. 491 00:20:40,470 --> 00:20:42,030 There's a lot of interpretation. 492 00:20:42,030 --> 00:20:44,300 And the combination of that bodily response and an 493 00:20:44,300 --> 00:20:46,960 interpretation leads you finally to the subjective 494 00:20:46,960 --> 00:20:50,440 experience you have, and probably works differently for 495 00:20:50,440 --> 00:20:51,200 different emotions. 496 00:20:51,200 --> 00:20:53,050 And things are complicated. 497 00:20:53,050 --> 00:20:57,350 But we're pretty far from this first guess in terms of the 498 00:20:57,350 --> 00:21:00,920 fact that peripheral things can have very powerful effects 499 00:21:00,920 --> 00:21:03,730 on how you interpret situations, the intensity of 500 00:21:03,730 --> 00:21:04,910 your interpretations. 501 00:21:04,910 --> 00:21:07,400 And the intensity itself can change the behaviors that 502 00:21:07,400 --> 00:21:09,580 follows the situation. 503 00:21:09,580 --> 00:21:12,410 Three questions in the field are, are emotions universal? 504 00:21:12,410 --> 00:21:14,110 Are they in you from when you're born? 505 00:21:14,110 --> 00:21:17,010 Are they the same for people around the world? 506 00:21:17,010 --> 00:21:18,895 Do they have unique physiological signatures? 507 00:21:18,895 --> 00:21:20,460 Could we define-- 508 00:21:20,460 --> 00:21:24,450 if we knew your heart rate, if we knew your pulse and so on, 509 00:21:24,450 --> 00:21:27,380 could we know what emotional state you're in. 510 00:21:27,380 --> 00:21:30,700 And then speculations as to why we have emotions at all. 511 00:21:30,700 --> 00:21:34,100 What's the use of having emotions? 512 00:21:34,100 --> 00:21:36,930 Brilliant as he is in so many ways, in many ways this 513 00:21:36,930 --> 00:21:39,930 dialogue began in modern times with Charles Darwin, who 514 00:21:39,930 --> 00:21:42,270 noticed that animals had very striking facial expressions, 515 00:21:42,270 --> 00:21:43,070 as we saw before. 516 00:21:43,070 --> 00:21:45,260 And that made him think about the evolution of facial 517 00:21:45,260 --> 00:21:46,540 expressions. 518 00:21:46,540 --> 00:21:51,360 This is one of his drawings of a cat. 519 00:21:51,360 --> 00:21:56,930 Here are infants having early displays of emotions, joy, 520 00:21:56,930 --> 00:22:00,490 disgust, surprise, sadness, anger, fear. 521 00:22:00,490 --> 00:22:03,140 So people have been very impressed that very early on 522 00:22:03,140 --> 00:22:05,600 infants are having the full array of expressions. 523 00:22:05,600 --> 00:22:07,500 Of course, they might see them. 524 00:22:07,500 --> 00:22:09,410 From moments from their birth they have people around them. 525 00:22:09,410 --> 00:22:13,920 But it's very early, that's almost for sure. 526 00:22:13,920 --> 00:22:15,430 A really interesting line of research-- and I'll show you 527 00:22:15,430 --> 00:22:17,810 an example-- has been looking at emotional expressions, 528 00:22:17,810 --> 00:22:20,970 emotional facial expressions, in people who are born deaf or 529 00:22:20,970 --> 00:22:24,040 born blind, so they never hear intonation. 530 00:22:24,040 --> 00:22:26,150 They never see a facial expression. 531 00:22:26,150 --> 00:22:29,150 They can't learn it from their environments. 532 00:22:29,150 --> 00:22:34,493 So they're sort of a natural window into is this inborn in 533 00:22:34,493 --> 00:22:37,520 us, or do we learn it from people around us? 534 00:22:37,520 --> 00:22:40,910 Here's an experiment where they took spontaneous facial 535 00:22:40,910 --> 00:22:43,970 expressions of emotion in athletes from both the 536 00:22:43,970 --> 00:22:45,670 Olympics and the Paralympics. 537 00:22:45,670 --> 00:22:47,760 And they looked especially at congenitally blind people, 538 00:22:47,760 --> 00:22:50,760 born blind, never saw a face, and sighted athletes. 539 00:22:50,760 --> 00:22:52,630 And they looked at the expressions after winning or 540 00:22:52,630 --> 00:22:55,880 losing an Olympic-level match. 541 00:22:55,880 --> 00:22:58,830 Before I show you this, you may know the story. 542 00:22:58,830 --> 00:23:02,860 What happens after an Olympic event? 543 00:23:02,860 --> 00:23:05,930 Somebody wins and where do they go? 544 00:23:05,930 --> 00:23:07,960 You know this podium thing? 545 00:23:07,960 --> 00:23:10,030 The gold medal winners up here, and the silvers here and 546 00:23:10,030 --> 00:23:11,090 the bronzes here. 547 00:23:11,090 --> 00:23:12,160 And they've also done studies--this 548 00:23:12,160 --> 00:23:13,880 is just a side note-- 549 00:23:13,880 --> 00:23:18,602 saying, who looks the happiest in those pictures? 550 00:23:18,602 --> 00:23:19,460 AUDIENCE: Bronze. 551 00:23:19,460 --> 00:23:20,960 PROFESSOR: The bronze medal winner. 552 00:23:20,960 --> 00:23:22,680 Who looks the saddest in those pictures? 553 00:23:22,680 --> 00:23:23,420 AUDIENCE: Silver. 554 00:23:23,420 --> 00:23:24,430 PROFESSOR: The silver, right? 555 00:23:24,430 --> 00:23:27,070 Because the bronze medal winner's going, thank goodness 556 00:23:27,070 --> 00:23:28,010 I came in third place. 557 00:23:28,010 --> 00:23:28,700 I'm on the podium. 558 00:23:28,700 --> 00:23:29,510 I have an Olympic medal. 559 00:23:29,510 --> 00:23:32,720 If I'm in fourth place, fourth through infinity gets the same 560 00:23:32,720 --> 00:23:34,350 Olympic medal, right? 561 00:23:34,350 --> 00:23:36,970 The silver medalist, what's he or she thinking? 562 00:23:36,970 --> 00:23:38,180 On average. 563 00:23:38,180 --> 00:23:41,590 Man, if I had just one more fraction of a millisecond, I 564 00:23:41,590 --> 00:23:44,110 could be the gold medalist. 565 00:23:44,110 --> 00:23:46,160 It's kind of an interesting thing of when we consider 566 00:23:46,160 --> 00:23:47,980 things satisfactory or not. 567 00:23:47,980 --> 00:23:50,390 But now let's turn back to this question. 568 00:23:50,390 --> 00:23:55,600 Here's two people who just lost Olympic medal matches. 569 00:23:55,600 --> 00:23:58,770 And your question is which is a sighted person and which is 570 00:23:58,770 --> 00:23:59,820 a blind person? 571 00:23:59,820 --> 00:24:02,560 And to the extent it's hard to be certain, that would be a 572 00:24:02,560 --> 00:24:06,350 big suggestion that these expressions are inborn in us, 573 00:24:06,350 --> 00:24:10,890 because a person who's never seen a sad expression still 574 00:24:10,890 --> 00:24:13,050 has a sad expression. 575 00:24:13,050 --> 00:24:16,020 And the answer is, that's the blind athlete and that's the 576 00:24:16,020 --> 00:24:16,800 sighted athlete. 577 00:24:16,800 --> 00:24:20,720 So it's pretty convincing, I think, that we're born with 578 00:24:20,720 --> 00:24:24,320 this set of expressions as a core entity of being human. 579 00:24:28,780 --> 00:24:30,630 Even though we're born with that, we live in different 580 00:24:30,630 --> 00:24:32,780 cultures, very different cultures around the world, and 581 00:24:32,780 --> 00:24:34,550 even within countries and across countries. 582 00:24:34,550 --> 00:24:37,470 So how universal are these sorts of things? 583 00:24:37,470 --> 00:24:41,870 And there's lots of evidence of a degree of influence of 584 00:24:41,870 --> 00:24:46,260 cultures around this core universality. 585 00:24:46,260 --> 00:24:48,720 So does a smile mean friendship to everyone? 586 00:24:48,720 --> 00:24:52,550 And again, Ekman and Izard made a big study in which they 587 00:24:52,550 --> 00:24:54,680 argued that as far as they can tell in looking around at 588 00:24:54,680 --> 00:24:58,690 facial expressions, there's six basic emotional 589 00:24:58,690 --> 00:25:03,860 expressions that signal feelings, happiness, sadness, 590 00:25:03,860 --> 00:25:08,070 fear, anger, surprise, or disgust. 591 00:25:08,070 --> 00:25:12,040 These are all people who are trained to try to make the 592 00:25:12,040 --> 00:25:14,300 perfect expression of those things. 593 00:25:14,300 --> 00:25:16,280 They look kind of weird by themselves, right? 594 00:25:16,280 --> 00:25:18,780 They look kind of weird. 595 00:25:18,780 --> 00:25:20,240 You don't see a neutral one here. 596 00:25:20,240 --> 00:25:21,370 Maybe we'll see a neutral one later. 597 00:25:21,370 --> 00:25:22,380 Neutral is kind of weird, because you 598 00:25:22,380 --> 00:25:23,710 go, well, it's neutral. 599 00:25:23,710 --> 00:25:27,310 But I can tell you, a totally neutral face looking at you 600 00:25:27,310 --> 00:25:28,680 can be kind of creepy. 601 00:25:28,680 --> 00:25:30,630 Because if you interact with somebody and they have no 602 00:25:30,630 --> 00:25:34,210 expression at all, it's a little disturbing. 603 00:25:34,210 --> 00:25:39,320 But these are ones are pretty universally recognized, but 604 00:25:39,320 --> 00:25:40,410 not completely. 605 00:25:40,410 --> 00:25:42,145 Let's take Westerners, people from the 606 00:25:42,145 --> 00:25:45,150 United States or Europe. 607 00:25:45,150 --> 00:25:46,100 We're not perfect in that. 608 00:25:46,100 --> 00:25:48,070 Even with these posed pictures, this is how often 609 00:25:48,070 --> 00:25:50,530 people came up with the correct labels. 610 00:25:50,530 --> 00:25:53,040 Pretty often, not perfect. 611 00:25:53,040 --> 00:25:55,100 There's a lot of mystery at the edges of this. 612 00:25:55,100 --> 00:25:57,310 But here's how people came up from non-Western cultures for 613 00:25:57,310 --> 00:25:58,830 the same Western faces. 614 00:25:58,830 --> 00:26:03,670 Well above chance, but not the same as Westerners looking at 615 00:26:03,670 --> 00:26:05,300 Western expressions. 616 00:26:05,300 --> 00:26:08,110 And it would reverse if Westerners had to look at 617 00:26:08,110 --> 00:26:09,080 non-Western expressions. 618 00:26:09,080 --> 00:26:12,990 So there's definitely a degree of cultural influences on the 619 00:26:12,990 --> 00:26:14,560 recognition of these expressions as well. 620 00:26:14,560 --> 00:26:17,770 It's partly innate and universal, and there's a 621 00:26:17,770 --> 00:26:21,420 cultural overlay as well. 622 00:26:21,420 --> 00:26:22,560 This is a joke. 623 00:26:22,560 --> 00:26:23,370 "Shoot! 624 00:26:23,370 --> 00:26:25,390 You've got not only the wrong planet, but you've got the 625 00:26:25,390 --> 00:26:26,240 wrong solar system. 626 00:26:26,240 --> 00:26:27,500 I mean, a wrong planet I can understand. 627 00:26:27,500 --> 00:26:29,510 But a wrong solar system--" And you can tell with just a 628 00:26:29,510 --> 00:26:32,310 little information that this is a sheepish smile of 629 00:26:32,310 --> 00:26:33,310 embarrassment. 630 00:26:33,310 --> 00:26:35,970 And this is a little bit of the body expression of a 631 00:26:35,970 --> 00:26:37,850 little bit of irksomeness. 632 00:26:37,850 --> 00:26:39,760 Irked. 633 00:26:39,760 --> 00:26:42,510 But here's an isolated pre-literate 634 00:26:42,510 --> 00:26:43,810 tribe in New Guinea. 635 00:26:43,810 --> 00:26:48,220 And that smile looks like the smile of any kid you ever saw. 636 00:26:48,220 --> 00:26:50,735 That's sadness, the sadness of any kid you every saw. 637 00:26:50,735 --> 00:26:54,370 That's a little bit of a disgust. 638 00:26:54,370 --> 00:26:56,570 And some people have built up a model, something like 639 00:26:56,570 --> 00:27:00,730 there's things in the environment that happen that 640 00:27:00,730 --> 00:27:04,560 drive some sort of facial affect program. 641 00:27:04,560 --> 00:27:08,760 Your muscles in your face move to express 6 or so different 642 00:27:08,760 --> 00:27:10,720 kinds of feelings. 643 00:27:10,720 --> 00:27:13,210 Cultural rules about what should you show, what should 644 00:27:13,210 --> 00:27:15,180 you not show in different cultures. 645 00:27:15,180 --> 00:27:18,530 Some face's expressions are more appreciated than others. 646 00:27:18,530 --> 00:27:20,540 And finally, all of that moves into the facial 647 00:27:20,540 --> 00:27:23,570 expression you make. 648 00:27:23,570 --> 00:27:26,290 So now the second question we have, we think to a first 649 00:27:26,290 --> 00:27:29,500 approximation emotions, at least as far as we can tell, 650 00:27:29,500 --> 00:27:33,590 are pretty universal but there's cultural and learned 651 00:27:33,590 --> 00:27:35,540 pieces as well. 652 00:27:35,540 --> 00:27:37,460 Do emotions have unique physiological signatures? 653 00:27:37,460 --> 00:27:38,340 Can we tell from your 654 00:27:38,340 --> 00:27:40,620 physiology what you're feeling? 655 00:27:40,620 --> 00:27:42,830 And there was a lot of hope that this would work, because 656 00:27:42,830 --> 00:27:45,320 intuitively emotions differ from one another. 657 00:27:45,320 --> 00:27:47,790 Our body feels different as we go from 658 00:27:47,790 --> 00:27:50,300 one emotion to another. 659 00:27:50,300 --> 00:27:53,330 And we use language words like "she got hot and bothered." 660 00:27:53,330 --> 00:27:56,550 "You make my blood boil." "He's just letting off steam." 661 00:27:56,550 --> 00:27:58,780 Different physiologies go with different feelings. 662 00:27:58,780 --> 00:28:01,300 And so people hoped they could make decision trees like this. 663 00:28:01,300 --> 00:28:03,150 Let's measure your heart rate, high or low. 664 00:28:03,150 --> 00:28:05,360 Well, if it's high, then we get your skin temperature. 665 00:28:05,360 --> 00:28:07,630 And then we can tell if you're angry or fear or sad. 666 00:28:07,630 --> 00:28:10,340 That you could make a decision tree by looking at peripheral 667 00:28:10,340 --> 00:28:11,950 measures of physiology. 668 00:28:11,950 --> 00:28:14,150 But it never worked. 669 00:28:14,150 --> 00:28:16,700 It's never been strongly discriminating. 670 00:28:16,700 --> 00:28:20,320 People have not been able to have a physiological 671 00:28:20,320 --> 00:28:23,030 fingerprint for the emotion that you feel that's 672 00:28:23,030 --> 00:28:25,210 reasonably accurate. 673 00:28:25,210 --> 00:28:26,592 Yes? 674 00:28:26,592 --> 00:28:28,593 AUDIENCE: So why are they [INAUDIBLE] as something that 675 00:28:28,593 --> 00:28:30,958 could go in that tree, for instance? 676 00:28:30,958 --> 00:28:33,190 Could they measure chemical concentrations in places? 677 00:28:33,190 --> 00:28:33,870 PROFESSOR: It's possible, yes. 678 00:28:33,870 --> 00:28:35,180 Here's a very good question. 679 00:28:35,180 --> 00:28:37,730 Here they're measuring peripheral physiology or 680 00:28:37,730 --> 00:28:40,030 autonomic systems, skin temperature, heart rate. 681 00:28:40,030 --> 00:28:42,580 Could there be other things like chemicals, right? 682 00:28:42,580 --> 00:28:46,720 So I'd say yes, but we just don't know them well enough. 683 00:28:46,720 --> 00:28:48,890 Or could you have brain measures that ultimately would 684 00:28:48,890 --> 00:28:50,010 be sophisticated enough? 685 00:28:50,010 --> 00:28:51,390 I can tell you that brain measures are not that 686 00:28:51,390 --> 00:28:52,530 good at that now. 687 00:28:52,530 --> 00:28:54,180 But could they be someday? 688 00:28:54,180 --> 00:28:54,890 Yes. 689 00:28:54,890 --> 00:28:59,210 So yes, it's the specific measures that we have. 690 00:28:59,210 --> 00:29:03,800 A really deep question will be at some level when you're 691 00:29:03,800 --> 00:29:06,960 fearful and I'm fearful, how identical will those be, 692 00:29:06,960 --> 00:29:09,070 depending on our cultural background, depending on 693 00:29:09,070 --> 00:29:11,500 situations we've experienced? 694 00:29:11,500 --> 00:29:14,300 We can both agree we're scared of something, but it could be 695 00:29:14,300 --> 00:29:15,550 pretty different. 696 00:29:17,500 --> 00:29:19,490 So it's a really deep question. 697 00:29:19,490 --> 00:29:21,650 In the end, how close are these things from one person 698 00:29:21,650 --> 00:29:22,850 to another? 699 00:29:22,850 --> 00:29:28,620 Now, at least at speculative is why we have emotions. 700 00:29:28,620 --> 00:29:33,380 And sometimes people think it's intrapersonal 701 00:29:33,380 --> 00:29:34,240 functions within us. 702 00:29:34,240 --> 00:29:36,920 We're organizing ourselves-- what's our basic feeling? 703 00:29:36,920 --> 00:29:39,290 Are we basically happy or sad about something or fearful of 704 00:29:39,290 --> 00:29:41,240 something?-- 705 00:29:41,240 --> 00:29:43,960 so that we use that feeling as a source of information to 706 00:29:43,960 --> 00:29:45,630 sort of pull ourselves to say, this is 707 00:29:45,630 --> 00:29:46,800 basically where I'm at. 708 00:29:46,800 --> 00:29:49,070 It's a source of information for me. 709 00:29:49,070 --> 00:29:51,760 And it can tell me what behavior makes sense to do in 710 00:29:51,760 --> 00:29:53,220 this context. 711 00:29:53,220 --> 00:29:55,640 And then from one person to another, interpersonally. 712 00:29:55,640 --> 00:29:56,610 What does that person feel? 713 00:29:56,610 --> 00:29:58,610 What am I signalling to that person? 714 00:29:58,610 --> 00:30:01,150 So here's an experiment. 715 00:30:01,150 --> 00:30:03,890 And I'll show you just a brief YouTube video on this, because 716 00:30:03,890 --> 00:30:06,210 I think it's really cute. 717 00:30:06,210 --> 00:30:08,380 But it's almost a life and death experiment, although no 718 00:30:08,380 --> 00:30:11,410 infant was harmed in the making of this experiment. 719 00:30:11,410 --> 00:30:15,270 So what they do is, this is a visual cliff. 720 00:30:15,270 --> 00:30:17,970 An infant is put on this, a very tiny baby. 721 00:30:17,970 --> 00:30:20,360 Here it's hard Plexiglas. 722 00:30:20,360 --> 00:30:24,020 There is no danger to the baby. 723 00:30:24,020 --> 00:30:26,500 But there is a drop here and a drop here. 724 00:30:26,500 --> 00:30:29,890 Now, as the baby approaches this, they're not used to the 725 00:30:29,890 --> 00:30:31,120 idea of Plexiglas. 726 00:30:31,120 --> 00:30:34,300 Even you and I would be pretty worried about that if it was 727 00:30:34,300 --> 00:30:35,700 on a larger scale. 728 00:30:35,700 --> 00:30:37,260 We'd want to be pretty sure about the strength of the 729 00:30:37,260 --> 00:30:40,450 Plexiglas But to the infant's eyes, they're approaching what 730 00:30:40,450 --> 00:30:42,460 they call a visual cliff. 731 00:30:42,460 --> 00:30:43,120 On the other side-- 732 00:30:43,120 --> 00:30:44,740 I'll show the film in a moment-- 733 00:30:44,740 --> 00:30:46,450 is a mother. 734 00:30:46,450 --> 00:30:50,030 And the mother can either be showing a positive expression 735 00:30:50,030 --> 00:30:51,070 or a negative expression. 736 00:30:51,070 --> 00:30:54,960 And look what happens to the infants in this perilous 737 00:30:54,960 --> 00:31:01,940 situation where they see a drop that's a big, and how 738 00:31:01,940 --> 00:31:05,630 much they trust their mother's expression to know what to do. 739 00:31:05,630 --> 00:31:09,120 So if the mother is looking happy, like it's OK. 740 00:31:09,120 --> 00:31:09,880 This is going to be great. 741 00:31:09,880 --> 00:31:11,100 We're having a lot of fun. 742 00:31:11,100 --> 00:31:13,970 3/4 of the time the infant goes for it. 743 00:31:13,970 --> 00:31:17,510 If the mother looks scary, never. 744 00:31:17,510 --> 00:31:22,120 They're making kind of a dangerous decision entirely on 745 00:31:22,120 --> 00:31:24,750 the facial expression of the mother and their trust that 746 00:31:24,750 --> 00:31:27,050 the mother knows the right thing to do and is giving them 747 00:31:27,050 --> 00:31:28,300 the right advice. 748 00:31:35,740 --> 00:31:37,820 Sometimes everything in psychology can just seem like, 749 00:31:37,820 --> 00:31:38,720 oh, it's just another thing. 750 00:31:38,720 --> 00:31:42,030 But facial expressions are an unbelievable powerful way that 751 00:31:42,030 --> 00:31:43,280 we communicate with one another. 752 00:31:47,050 --> 00:31:51,660 Here's an extremely clever experiment from Adam Anderson, 753 00:31:51,660 --> 00:31:54,540 who happened to be a postdoctoral fellow in my lab, 754 00:31:54,540 --> 00:31:57,200 but he did this completely independently. 755 00:31:57,200 --> 00:31:57,970 Here's the question. 756 00:31:57,970 --> 00:31:59,640 So we have some different expressions. 757 00:31:59,640 --> 00:32:03,390 And you could say, well, are they completely random as to 758 00:32:03,390 --> 00:32:05,310 what the actual expression is? 759 00:32:05,310 --> 00:32:06,330 We haven't even asked this. 760 00:32:06,330 --> 00:32:08,610 Why does a smile go one way and a frown go the other way? 761 00:32:08,610 --> 00:32:12,200 Does it mean anything or are they just arbitrary signals of 762 00:32:12,200 --> 00:32:14,820 different emotions that have evolved over time? 763 00:32:14,820 --> 00:32:17,385 And he's almost the first person I know to 764 00:32:17,385 --> 00:32:18,600 even ask this question. 765 00:32:18,600 --> 00:32:22,980 And he looked at two emotions that we'll come back to in 766 00:32:22,980 --> 00:32:28,540 just a little bit, fear, and disgust. 767 00:32:28,540 --> 00:32:31,830 And he thought, well, look, it's kind of interesting what 768 00:32:31,830 --> 00:32:32,660 fear and disgust do. 769 00:32:32,660 --> 00:32:36,340 For example, fear, your eyes get bigger, disgust-- 770 00:32:36,340 --> 00:32:41,770 think about something really stinky-- 771 00:32:41,770 --> 00:32:42,580 you close your eyes. 772 00:32:42,580 --> 00:32:44,490 You sort of scrunch up your nose. 773 00:32:44,490 --> 00:32:45,330 Look at this. 774 00:32:45,330 --> 00:32:48,830 And he looked at and measured how airflow patterns and 775 00:32:48,830 --> 00:32:52,150 different things happen when you go into those expressions, 776 00:32:52,150 --> 00:32:56,610 non-arbitrary properties of an expression. 777 00:32:56,610 --> 00:32:58,100 And then he did psychological expressions. 778 00:32:58,100 --> 00:33:00,620 He got people to get into these expressions. 779 00:33:00,620 --> 00:33:03,560 And he found that if they were in a fearful expression, that 780 00:33:03,560 --> 00:33:08,490 they would feel like they had a wider field of view, and if 781 00:33:08,490 --> 00:33:10,820 it's disgust, a smaller. 782 00:33:10,820 --> 00:33:12,720 Now think about this for a moment. 783 00:33:12,720 --> 00:33:16,020 When it's fearful, do you want to feel like you know what's 784 00:33:16,020 --> 00:33:18,390 going on around you? 785 00:33:18,390 --> 00:33:21,210 Or do you want to sit back and think about stuff? 786 00:33:21,210 --> 00:33:22,880 Or do you want to say like, uh-oh. 787 00:33:22,880 --> 00:33:23,570 Where do I run? 788 00:33:23,570 --> 00:33:25,020 What's going on? 789 00:33:25,020 --> 00:33:29,480 When you go into some disgusting situation, do you 790 00:33:29,480 --> 00:33:31,020 want to really look around a lot? 791 00:33:31,020 --> 00:33:34,150 Or are you kind of happy to find some way out of it? 792 00:33:34,150 --> 00:33:36,420 Same thing with your nose. 793 00:33:36,420 --> 00:33:40,390 Here's the air velocity that's passing through your nose when 794 00:33:40,390 --> 00:33:42,940 you're fearful and when you're disgusted. 795 00:33:42,940 --> 00:33:44,980 Now you don't even think about that. 796 00:33:44,980 --> 00:33:47,980 Who's thinking, I'm controlling my air velocity? 797 00:33:47,980 --> 00:33:51,420 But why do you think you might want to really sample your 798 00:33:51,420 --> 00:33:56,420 environment when you feel danger, visually and in an 799 00:33:56,420 --> 00:33:56,990 olfactory way? 800 00:33:56,990 --> 00:33:58,240 Why do you think you might want to sample? 801 00:33:58,240 --> 00:33:59,450 Well, you want to know what's going on. 802 00:33:59,450 --> 00:34:01,690 You want the information as fast as possible. 803 00:34:01,690 --> 00:34:02,360 Do I run? 804 00:34:02,360 --> 00:34:03,200 Do I duck? 805 00:34:03,200 --> 00:34:03,890 What do I do? 806 00:34:03,890 --> 00:34:04,960 Do I fight, flee? 807 00:34:04,960 --> 00:34:05,605 What do I do? 808 00:34:05,605 --> 00:34:08,940 I have moments to decide, because I'm in danger. 809 00:34:08,940 --> 00:34:11,790 If you're in a disgust situation, are you interested, 810 00:34:11,790 --> 00:34:14,750 typically, in exploring the olfactory environment in as 811 00:34:14,750 --> 00:34:18,080 much detail as you can? 812 00:34:18,080 --> 00:34:19,510 Usually not. 813 00:34:19,510 --> 00:34:20,699 So it's kind of interesting. 814 00:34:20,699 --> 00:34:21,372 The very first time -- 815 00:34:21,372 --> 00:34:23,000 I know, it's very clever -- 816 00:34:23,000 --> 00:34:25,699 asked where do these expressions come from? 817 00:34:25,699 --> 00:34:28,940 Well, maybe they tend, to a certain extent, to exaggerate 818 00:34:28,940 --> 00:34:32,409 or diminish forms of sensory input that are relevant for 819 00:34:32,409 --> 00:34:35,159 the emotion. 820 00:34:35,159 --> 00:34:37,500 So for the last little bit I'm going to talk about for a 821 00:34:37,500 --> 00:34:39,360 little while what we know about the brain 822 00:34:39,360 --> 00:34:40,550 basis of some emotions. 823 00:34:40,550 --> 00:34:43,290 We already talked about the idea that the amygdala plays a 824 00:34:43,290 --> 00:34:44,210 special role in fear. 825 00:34:44,210 --> 00:34:45,659 And I'll show you a couple different ways in 826 00:34:45,659 --> 00:34:46,929 which that's true. 827 00:34:46,929 --> 00:34:49,949 This is just sitting in front of the hippocampus, one on the 828 00:34:49,949 --> 00:34:51,760 left, one on the right, the core elements 829 00:34:51,760 --> 00:34:53,889 of your limbic system. 830 00:34:53,889 --> 00:34:55,820 Here it is viewed from the side, the amygdala. 831 00:34:58,720 --> 00:35:03,520 Here's the actual amygdala from a post-mortem brain. 832 00:35:03,520 --> 00:35:05,890 And there's another whole level of analysis that animal 833 00:35:05,890 --> 00:35:08,140 researchers do that we can't touch today, which is the 834 00:35:08,140 --> 00:35:11,670 amygdala itself is made out of bundles of neurons called 835 00:35:11,670 --> 00:35:14,300 nuclei, very distinct ones that have different roles, 836 00:35:14,300 --> 00:35:16,140 different inputs, different outputs. 837 00:35:16,140 --> 00:35:19,940 And in animal research, where you can selectively influence 838 00:35:19,940 --> 00:35:22,180 one or the other, you can see they have quite different 839 00:35:22,180 --> 00:35:24,070 specific roles. 840 00:35:24,070 --> 00:35:26,500 In humans we don't have that precision of control, so we 841 00:35:26,500 --> 00:35:28,740 sort of have some clump average 842 00:35:28,740 --> 00:35:30,530 statements about the amygdala. 843 00:35:30,530 --> 00:35:33,350 But really we're mixing together a few functions. 844 00:35:33,350 --> 00:35:37,200 So you already saw this picture, that animals, mice or 845 00:35:37,200 --> 00:35:40,050 rats, that have an amygdala removed lose the fear they 846 00:35:40,050 --> 00:35:41,395 ought to have of a cat. 847 00:35:44,640 --> 00:35:46,570 In primate studies, they found that if they have amygdala 848 00:35:46,570 --> 00:35:50,610 lesions, the loss of threat appreciation impairs social 849 00:35:50,610 --> 00:35:52,460 fitness, that animals that don't know what they ought to 850 00:35:52,460 --> 00:35:55,730 be afraid of get into big trouble. 851 00:35:55,730 --> 00:35:58,560 They lose their position in dominance hierarchies. 852 00:35:58,560 --> 00:36:00,830 You may know primate groups tend to have dominance 853 00:36:00,830 --> 00:36:03,170 hierarchies, a sort of alpha male and so on. 854 00:36:03,170 --> 00:36:05,800 They slide down that. 855 00:36:05,800 --> 00:36:08,360 If they lesion the dominant male, the alpha male, the male 856 00:36:08,360 --> 00:36:10,930 who wins all the fights and controls the group, that 857 00:36:10,930 --> 00:36:13,850 animal will fall down the hierarchy and become 858 00:36:13,850 --> 00:36:15,690 subordinate. 859 00:36:15,690 --> 00:36:18,130 And in the wild, they've shown that if they do lesions and 860 00:36:18,130 --> 00:36:19,930 return the animal to the social situation, they get 861 00:36:19,930 --> 00:36:22,980 rejected by the other animals, because the other animals feel 862 00:36:22,980 --> 00:36:24,300 there's something weird about the animals. 863 00:36:24,300 --> 00:36:26,840 And they're often isolated and they get to early death, 864 00:36:26,840 --> 00:36:28,210 because the other animals are not helping them 865 00:36:28,210 --> 00:36:29,550 or supporting them. 866 00:36:29,550 --> 00:36:33,400 So very important for learning what's dangerous. 867 00:36:33,400 --> 00:36:36,130 Here's an experiment with rhesus monkeys lesioned at two 868 00:36:36,130 --> 00:36:38,660 weeks as infants, returned to their mothers, and tested at 869 00:36:38,660 --> 00:36:39,660 eight weeks. 870 00:36:39,660 --> 00:36:43,130 And here's an example of something, this is if you show 871 00:36:43,130 --> 00:36:45,310 an animal a novel object. 872 00:36:45,310 --> 00:36:47,950 And this is how often they respond to it. 873 00:36:47,950 --> 00:36:52,590 Young animals will often not explore it, because they go, 874 00:36:52,590 --> 00:36:53,050 well, I don't know. 875 00:36:53,050 --> 00:36:54,560 That could be dangerous. 876 00:36:54,560 --> 00:36:57,090 They're waiting for their mother's expression. 877 00:36:57,090 --> 00:36:59,420 Here's the other animals with the amygdala lesions. 878 00:36:59,420 --> 00:37:00,800 They'll explore it. 879 00:37:00,800 --> 00:37:03,090 In a sense, they're fearless. 880 00:37:03,090 --> 00:37:05,820 But that's probably not an ideal thing to do when you're 881 00:37:05,820 --> 00:37:08,880 an infant exploring the world. 882 00:37:08,880 --> 00:37:17,350 Or they'll put food only or food next to a play snake. 883 00:37:17,350 --> 00:37:19,460 Snakes are dangerous for monkeys. 884 00:37:19,460 --> 00:37:22,360 They usually don't want to figure out at this age is it a 885 00:37:22,360 --> 00:37:24,480 play snake or a real snake? 886 00:37:24,480 --> 00:37:27,480 They just say, I don't really need to eat that. 887 00:37:27,480 --> 00:37:29,400 So everybody likes the food. 888 00:37:29,400 --> 00:37:32,070 Put the snake next to it, and the control animals go, no, I 889 00:37:32,070 --> 00:37:34,800 don't think so, basically. 890 00:37:34,800 --> 00:37:37,520 The amygdala ones, what's for dinner? 891 00:37:37,520 --> 00:37:40,260 And the answer is, if it's a real snake, you're for dinner. 892 00:37:40,260 --> 00:37:43,180 So they lose the fear of things they ought to have fear 893 00:37:43,180 --> 00:37:47,700 of, they lose fear of unknown things, fear of things they 894 00:37:47,700 --> 00:37:49,190 ought to be afraid of. 895 00:37:49,190 --> 00:37:51,290 So the amygdala plays this really important role. 896 00:37:51,290 --> 00:37:55,180 Fear sometimes is maybe the best understood emotion in 897 00:37:55,180 --> 00:37:58,430 terms of brain processes, and maybe the most studied, partly 898 00:37:58,430 --> 00:38:00,130 because we've had some success in understanding what's going 899 00:38:00,130 --> 00:38:03,080 on and partly because fear is maybe the emotion that most 900 00:38:03,080 --> 00:38:04,780 people think is closer to survival. 901 00:38:04,780 --> 00:38:06,110 You fear what kills you. 902 00:38:06,110 --> 00:38:07,510 You fear what pains you. 903 00:38:07,510 --> 00:38:12,640 That's a very powerful emotion for survival and safety. 904 00:38:12,640 --> 00:38:14,310 And you can do fear conditioning. 905 00:38:14,310 --> 00:38:17,510 We talked about conditioning before in all species, from 906 00:38:17,510 --> 00:38:22,050 humans to primates, other mammals, fruit flies. 907 00:38:22,050 --> 00:38:26,310 All of them have, to a first approximation, similar fear 908 00:38:26,310 --> 00:38:26,890 conditioning. 909 00:38:26,890 --> 00:38:30,220 It's as if you're alive, you have to fear things that are 910 00:38:30,220 --> 00:38:32,960 scary and dangerous. 911 00:38:32,960 --> 00:38:34,680 So people have done fear conditioning experiments. 912 00:38:34,680 --> 00:38:36,370 And now you know this very well. 913 00:38:36,370 --> 00:38:39,090 You might hear a tone that's not scary at first. 914 00:38:39,090 --> 00:38:41,780 If you put it with something that you don't like, like a 915 00:38:41,780 --> 00:38:44,590 foot shock, you get fearful to the tone. 916 00:38:44,590 --> 00:38:47,340 And what people have discovered kind of remarkably 917 00:38:47,340 --> 00:38:49,920 is that you can make lesions in many parts of the brain and 918 00:38:49,920 --> 00:38:54,880 you don't affect that learned fearfulness to the tone. 919 00:38:54,880 --> 00:38:57,940 But if you make a damage in the part of the amygdala, you 920 00:38:57,940 --> 00:38:58,940 abolish that learning. 921 00:38:58,940 --> 00:39:03,500 These animals fail to learn the signal of something that 922 00:39:03,500 --> 00:39:06,050 is coming up to be painful and dangerous. 923 00:39:06,050 --> 00:39:08,700 And you can even make large lesions in the cortex. 924 00:39:08,700 --> 00:39:10,490 That doesn't affect anything. 925 00:39:10,490 --> 00:39:12,740 And these animals with the amygdala lesions, they have an 926 00:39:12,740 --> 00:39:14,690 intact unconditioned response. 927 00:39:14,690 --> 00:39:17,930 When they get the shock, they jump like the other animals. 928 00:39:17,930 --> 00:39:18,910 They don't like it. 929 00:39:18,910 --> 00:39:21,340 It's not that they can't feel pain. 930 00:39:21,340 --> 00:39:25,260 They can't learn that the tone predicts the painful stimulus. 931 00:39:25,260 --> 00:39:27,270 They can't learn the warning signal of danger. 932 00:39:30,180 --> 00:39:33,610 There's very few patients with amygdala injuries only. 933 00:39:33,610 --> 00:39:34,730 But there's a few. 934 00:39:34,730 --> 00:39:36,960 So here's a patient, SM, who's been studied by Damasio and 935 00:39:36,960 --> 00:39:38,420 his colleagues. 936 00:39:38,420 --> 00:39:40,410 This is where the amygdala ought to be. 937 00:39:40,410 --> 00:39:43,870 It's a developmental disorder where this is calcified very 938 00:39:43,870 --> 00:39:44,820 early in development. 939 00:39:44,820 --> 00:39:45,870 It's not an adult lesion. 940 00:39:45,870 --> 00:39:47,200 But it seems to be fairly amygdala-specific. 941 00:39:50,150 --> 00:39:51,050 And people have done a couple of 942 00:39:51,050 --> 00:39:52,320 experiments with these patients. 943 00:39:52,320 --> 00:39:54,580 And it's sort of guided our understanding of what the 944 00:39:54,580 --> 00:39:58,240 amygdala does in you and I. Here's one example where they 945 00:39:58,240 --> 00:39:59,230 did conditioning. 946 00:39:59,230 --> 00:40:01,340 Again, in this case they didn't use shocks. 947 00:40:01,340 --> 00:40:04,560 They used a super-loud boat horn that's 948 00:40:04,560 --> 00:40:05,840 pretty noxious to people. 949 00:40:05,840 --> 00:40:07,120 People don't like it. 950 00:40:07,120 --> 00:40:09,580 And they preceded that with something gentle that warned 951 00:40:09,580 --> 00:40:12,190 you it was coming. 952 00:40:12,190 --> 00:40:13,360 Here's the initial response. 953 00:40:13,360 --> 00:40:15,130 And here's the important thing. 954 00:40:15,130 --> 00:40:16,390 With humans, of course you can-- 955 00:40:16,390 --> 00:40:20,200 well, let me just say they managed a skin response, a 956 00:40:20,200 --> 00:40:23,530 galvanic skin response to the bad tones. 957 00:40:23,530 --> 00:40:29,750 So here's the conditioned stimulus, the response to the 958 00:40:29,750 --> 00:40:32,590 boat horns in the conditioning, what predicts 959 00:40:32,590 --> 00:40:33,760 the boat horns. 960 00:40:33,760 --> 00:40:37,460 Here's the response to the baseline. 961 00:40:37,460 --> 00:40:41,080 And here's the performance of patients with amnesia who have 962 00:40:41,080 --> 00:40:42,250 the amygdala-- 963 00:40:42,250 --> 00:40:45,770 controls, I'm sorry, who both can tell you they're 964 00:40:45,770 --> 00:40:48,630 responding selectively to the scariest tones and also 965 00:40:48,630 --> 00:40:50,080 remember perfectly well. 966 00:40:50,080 --> 00:40:53,570 At the end of the testing session, you go, what went on? 967 00:40:53,570 --> 00:40:54,720 And they say, oh yes. 968 00:40:54,720 --> 00:40:56,980 Well, when I got one signal I got a horrible boat horn. 969 00:40:56,980 --> 00:40:58,720 And when I heard the other signal, I got nothing. 970 00:40:58,720 --> 00:40:59,920 It's easy. 971 00:40:59,920 --> 00:41:01,560 You do that for half an hour. 972 00:41:01,560 --> 00:41:04,280 You get one visual signal that means boat horn coming up, one 973 00:41:04,280 --> 00:41:06,540 visual signal, nothing coming up. 974 00:41:06,540 --> 00:41:08,670 If you have patients who have amygdala lesions, that 975 00:41:08,670 --> 00:41:11,180 galvanic skin response doesn't happen, even though they tell 976 00:41:11,180 --> 00:41:13,470 you perfectly well afterwards what happened. 977 00:41:13,470 --> 00:41:16,440 So they know just like everybody else that they got a 978 00:41:16,440 --> 00:41:19,840 certain signal that went with a noxious boat horn. 979 00:41:19,840 --> 00:41:23,930 But their body is not learning that association. 980 00:41:23,930 --> 00:41:27,780 If a patient has hippocampal damage, their body learns that 981 00:41:27,780 --> 00:41:29,960 association, but they don't remember it afterwards 982 00:41:29,960 --> 00:41:31,490 consciously. 983 00:41:31,490 --> 00:41:33,540 So you can separate out two kinds of learning, a 984 00:41:33,540 --> 00:41:38,080 hippocampal-dependent learning of the facts of the session, 985 00:41:38,080 --> 00:41:40,700 and an amygdala-dependent learning, which is a bodily 986 00:41:40,700 --> 00:41:43,380 response to learning that something is dangerous and 987 00:41:43,380 --> 00:41:44,630 unpleasant. 988 00:41:46,360 --> 00:41:49,510 Now, we often learn things like the visual cliff without 989 00:41:49,510 --> 00:41:52,370 having to have a boat horn and practice, right? 990 00:41:52,370 --> 00:41:54,850 If somebody tells you that something is dangerous, or you 991 00:41:54,850 --> 00:41:57,760 figure out that something is dangerous, you don't have to 992 00:41:57,760 --> 00:42:00,870 go through a terrible experience to pretty much 993 00:42:00,870 --> 00:42:02,550 decide you're not going to do it. 994 00:42:02,550 --> 00:42:08,450 So here's an experiment that was aimed at showing you that. 995 00:42:08,450 --> 00:42:11,240 What people were shown-- there's a funny human subjects 996 00:42:11,240 --> 00:42:12,330 wrinkle to this I'll just tell you. 997 00:42:12,330 --> 00:42:14,320 This occurred at Yale, where they had a 998 00:42:14,320 --> 00:42:15,500 blue square came on. 999 00:42:15,500 --> 00:42:16,310 That means safe. 1000 00:42:16,310 --> 00:42:17,360 You can just relax. 1001 00:42:17,360 --> 00:42:19,410 Nothing bad's going to happen. 1002 00:42:19,410 --> 00:42:21,850 But when the yellow square comes on, get ready. 1003 00:42:21,850 --> 00:42:25,170 You might get a somewhat unpleasant shock. 1004 00:42:25,170 --> 00:42:29,270 But they never give them a shock. 1005 00:42:29,270 --> 00:42:31,180 So you're not learning that way. 1006 00:42:31,180 --> 00:42:33,670 You just factually learn that something is safe and 1007 00:42:33,670 --> 00:42:35,120 something is dangerous. 1008 00:42:35,120 --> 00:42:38,960 And here is the amygdala response to the scary one, to 1009 00:42:38,960 --> 00:42:41,120 a neutral situation, and to the one where you 1010 00:42:41,120 --> 00:42:43,930 know, ah, I'm safe. 1011 00:42:43,930 --> 00:42:45,640 So you never got the shock. 1012 00:42:45,640 --> 00:42:47,030 You never got the shock. 1013 00:42:47,030 --> 00:42:48,890 You were just told about the shock. 1014 00:42:48,890 --> 00:42:50,650 You didn't have to get it, but you're human. 1015 00:42:50,650 --> 00:42:51,840 You can figure this out. 1016 00:42:51,840 --> 00:42:54,060 And your amygdala is going, you know, I can just figure 1017 00:42:54,060 --> 00:42:55,700 out that's dangerous. 1018 00:42:55,700 --> 00:42:57,040 That's baseline. 1019 00:42:57,040 --> 00:43:00,610 And that's the absence of danger, positive safety. 1020 00:43:03,500 --> 00:43:07,770 The Yale IRB, hilariously I think, said, oh, but you're 1021 00:43:07,770 --> 00:43:10,210 deceiving the people, because you tell them they might get a 1022 00:43:10,210 --> 00:43:11,500 shock and they never got a shock. 1023 00:43:11,500 --> 00:43:13,410 So you have to give them one shock at the end of the 1024 00:43:13,410 --> 00:43:15,780 experiment. 1025 00:43:15,780 --> 00:43:17,370 So dutifully, the experimenters gave them one 1026 00:43:17,370 --> 00:43:20,390 shock after the experiment was over so they were honest. 1027 00:43:20,390 --> 00:43:22,890 Because during the experiment, as they measured the brain 1028 00:43:22,890 --> 00:43:26,440 activation in the amygdala responding to the threat of 1029 00:43:26,440 --> 00:43:29,050 pain without any pain being associated-- 1030 00:43:29,050 --> 00:43:29,560 we're smart. 1031 00:43:29,560 --> 00:43:31,560 We can learn something is dangerous just by thinking it 1032 00:43:31,560 --> 00:43:34,440 through, and it engages the same part of the brain that 1033 00:43:34,440 --> 00:43:38,300 learns by actual painful experience. 1034 00:43:38,300 --> 00:43:40,210 Now how about memory? 1035 00:43:40,210 --> 00:43:43,580 So here's the way this study was done. 1036 00:43:43,580 --> 00:43:45,210 People viewed a slide story with an 1037 00:43:45,210 --> 00:43:46,360 emotional middle section. 1038 00:43:46,360 --> 00:43:49,550 So an example would be this, parents are home having 1039 00:43:49,550 --> 00:43:52,580 breakfast with a kid. 1040 00:43:52,580 --> 00:43:53,540 Parents go to work. 1041 00:43:53,540 --> 00:43:57,050 Kid walks to school, kind of tragically, but these are all 1042 00:43:57,050 --> 00:43:58,940 slides, again, nobody was injured, 1043 00:43:58,940 --> 00:44:00,640 child is hit by a car. 1044 00:44:00,640 --> 00:44:02,120 Something high arousing happens in the 1045 00:44:02,120 --> 00:44:03,140 middle of the story. 1046 00:44:03,140 --> 00:44:04,290 Everybody runs to the hospital. 1047 00:44:04,290 --> 00:44:06,290 The kid is OK. 1048 00:44:06,290 --> 00:44:09,580 When people ask a week later or something like that, a week 1049 00:44:09,580 --> 00:44:12,960 later, tell me about the stories I told you last week. 1050 00:44:12,960 --> 00:44:14,220 There's a number of stories. 1051 00:44:14,220 --> 00:44:17,130 People have best memory for the part where something 1052 00:44:17,130 --> 00:44:19,660 highly arousing happened, like the child was hit by a car. 1053 00:44:19,660 --> 00:44:21,115 That makes sense, right? 1054 00:44:21,115 --> 00:44:22,510 Kid having breakfast, huh. 1055 00:44:22,510 --> 00:44:24,190 Kid OK, huh. 1056 00:44:24,190 --> 00:44:26,450 Car accident with a kid, you're aroused and you 1057 00:44:26,450 --> 00:44:27,540 remember that better. 1058 00:44:27,540 --> 00:44:30,750 Emotion is amplifying memory. 1059 00:44:30,750 --> 00:44:34,000 The patients with the amygdala lesions don't have that memory 1060 00:44:34,000 --> 00:44:36,290 bump based on emotion. 1061 00:44:36,290 --> 00:44:39,050 The emotion is not enhancing their memory. 1062 00:44:39,050 --> 00:44:41,310 And you can imagine that there's a pretty good reason 1063 00:44:41,310 --> 00:44:43,900 for emotions to enhance memory, right? 1064 00:44:43,900 --> 00:44:48,070 If something is fearful, delightful, horribly 1065 00:44:48,070 --> 00:44:51,640 disgusting, those are all good reasons to remember. 1066 00:44:51,640 --> 00:44:53,510 Let's do that again, if it's great. 1067 00:44:53,510 --> 00:44:56,060 Let's avoid that, if it's terrible. 1068 00:44:56,060 --> 00:44:59,100 It's a good idea for emotions to drive memory formation. 1069 00:44:59,100 --> 00:45:02,270 And in your brain and mine, it appears the amygdala has this 1070 00:45:02,270 --> 00:45:05,845 role of transforming emotions into memories. 1071 00:45:09,950 --> 00:45:13,370 Now we also talked about six facial expressions. 1072 00:45:13,370 --> 00:45:14,470 And I showed you this before. 1073 00:45:14,470 --> 00:45:18,380 The same patients have trouble in recognizing fearful facial 1074 00:45:18,380 --> 00:45:18,880 expressions. 1075 00:45:18,880 --> 00:45:23,720 So the amygdala in so many different ways, learning, 1076 00:45:23,720 --> 00:45:27,510 memory, perception of faces, seems to play this 1077 00:45:27,510 --> 00:45:29,490 huge role in fear. 1078 00:45:32,240 --> 00:45:35,710 And kind of interesting way, because you might have the 1079 00:45:35,710 --> 00:45:36,370 intuition-- 1080 00:45:36,370 --> 00:45:40,050 and a lot of this came from Freud-- 1081 00:45:40,050 --> 00:45:42,800 that a lot of emotions are happening kind of under our 1082 00:45:42,800 --> 00:45:44,390 conscious awareness. 1083 00:45:44,390 --> 00:45:47,180 We almost discover them after, like why am I angry with this 1084 00:45:47,180 --> 00:45:48,520 person, or why am I so happy? 1085 00:45:48,520 --> 00:45:50,790 We have to think it through, almost. 1086 00:45:50,790 --> 00:45:53,940 If you show subliminal fearful faces versus happy faces, 1087 00:45:53,940 --> 00:45:58,190 subliminally presented so people can't tell you what the 1088 00:45:58,190 --> 00:46:02,330 facial expression was, still they turn on the amygdala. 1089 00:46:02,330 --> 00:46:05,330 So unconscious perception of a fearful 1090 00:46:05,330 --> 00:46:06,790 face engages the amygdala. 1091 00:46:06,790 --> 00:46:09,400 You don't have to go through consciousness. 1092 00:46:09,400 --> 00:46:10,880 Cortical blindness. 1093 00:46:10,880 --> 00:46:12,475 We talked about that earlier in the course, where you're 1094 00:46:12,475 --> 00:46:14,715 blind in one visual field. 1095 00:46:14,715 --> 00:46:17,660 And yet individual patients, a couple of them with cortical 1096 00:46:17,660 --> 00:46:20,460 blindness, if they were shown a fearful stimulus in the 1097 00:46:20,460 --> 00:46:23,990 cortically blind field, still turn on, in the cortically 1098 00:46:23,990 --> 00:46:27,910 blind field, the amygdala for a fearful face versus a happy 1099 00:46:27,910 --> 00:46:32,250 face, which indicates that a non-conscious, subcortical 1100 00:46:32,250 --> 00:46:36,720 pathway that doesn't intersect with conscious thought or 1101 00:46:36,720 --> 00:46:40,000 cortex, is sending information from your eyes to your 1102 00:46:40,000 --> 00:46:43,020 amygdala, a different pathway. 1103 00:46:43,020 --> 00:46:47,270 And people have speculated that maybe again because fear 1104 00:46:47,270 --> 00:46:50,580 is survival and danger, we might have a super-highway of 1105 00:46:50,580 --> 00:46:53,180 information that sends dangerous information 1106 00:46:53,180 --> 00:46:54,550 immediately to our amygdala. 1107 00:46:54,550 --> 00:46:57,370 It doesn't wait for you to think a lot, so to speak, in 1108 00:46:57,370 --> 00:46:58,200 your cortex. 1109 00:46:58,200 --> 00:46:59,680 Boom. 1110 00:46:59,680 --> 00:47:02,720 Danger, danger, danger, even before you process the rest of 1111 00:47:02,720 --> 00:47:04,570 the situation. 1112 00:47:04,570 --> 00:47:07,840 So we talked about fear and the threat in the amygdala. 1113 00:47:07,840 --> 00:47:10,430 I'll just say a word about disgust. 1114 00:47:10,430 --> 00:47:13,750 People think there's many reasons things we can be 1115 00:47:13,750 --> 00:47:16,650 disgusted at or about, but that maybe in terms of 1116 00:47:16,650 --> 00:47:18,680 evolution, it might have been a pretty good signal for 1117 00:47:18,680 --> 00:47:22,750 contaminated food, food that makes you sick, things to 1118 00:47:22,750 --> 00:47:24,380 avoid that make you sick. 1119 00:47:24,380 --> 00:47:27,300 And it turns out another part of the brain called the insula 1120 00:47:27,300 --> 00:47:30,100 is pretty important for that. 1121 00:47:30,100 --> 00:47:32,030 So here's the amygdala left and right. 1122 00:47:32,030 --> 00:47:33,850 Here's the insula that you have, left and 1123 00:47:33,850 --> 00:47:36,470 right, outlined in purple. 1124 00:47:36,470 --> 00:47:40,320 And again, just like with the amygdala, patients with 1125 00:47:40,320 --> 00:47:43,790 lesions of the insula don't recognize facial expressions. 1126 00:47:43,790 --> 00:47:46,790 And imaging wise, if you see a disgusted face, that turns on 1127 00:47:46,790 --> 00:47:48,210 that part of the brain as well. 1128 00:47:48,210 --> 00:47:52,000 So those are the best understood brain pieces of 1129 00:47:52,000 --> 00:47:53,990 emotion by far. 1130 00:47:53,990 --> 00:47:56,120 So now those are patient things, so let me turn for a 1131 00:47:56,120 --> 00:47:59,540 moment, lastly to a few imaging studies of typical 1132 00:47:59,540 --> 00:48:02,290 people and some topics on emotion. 1133 00:48:02,290 --> 00:48:06,260 So here's some terrible pictures from 9/11. 1134 00:48:06,260 --> 00:48:08,240 "The horror of the moment"-- and we always 1135 00:48:08,240 --> 00:48:09,290 imagine we'll remember-- 1136 00:48:09,290 --> 00:48:10,610 and we've already talked a little bit about this in 1137 00:48:10,610 --> 00:48:11,740 flashbulb memories-- 1138 00:48:11,740 --> 00:48:14,110 emotionally things correctly for a long time. 1139 00:48:14,110 --> 00:48:15,530 "'The horrors of that moment,' the King went on, 'I shall 1140 00:48:15,530 --> 00:48:17,020 never forget.'" This is Lewis Carroll, 1141 00:48:17,020 --> 00:48:18,180 Through the Looking Glass. 1142 00:48:18,180 --> 00:48:19,910 "'You will though,' the Queen said, 'if you don't make a 1143 00:48:19,910 --> 00:48:20,720 memorandum of it.'" 1144 00:48:20,720 --> 00:48:22,470 And now you know that Lewis Carroll was talking about the 1145 00:48:22,470 --> 00:48:23,760 amygdala, right? 1146 00:48:23,760 --> 00:48:25,600 You didn't know that before, but you know that now. 1147 00:48:25,600 --> 00:48:28,830 Because if the amygdala isn't there, the emotional intensity 1148 00:48:28,830 --> 00:48:33,660 doesn't make the memory more permanent or more powerful. 1149 00:48:33,660 --> 00:48:37,040 So Larry Cahill at UC Irvine did the first brain study on 1150 00:48:37,040 --> 00:48:37,990 this topic. 1151 00:48:37,990 --> 00:48:41,280 And what he did is he showed students while they were 1152 00:48:41,280 --> 00:48:46,800 getting PET scanning, Positron Emission Tomography, short 1153 00:48:46,800 --> 00:48:48,450 films that were either powerfully 1154 00:48:48,450 --> 00:48:51,480 emotional or neutral. 1155 00:48:51,480 --> 00:48:54,280 And then he brought them back three weeks later. 1156 00:48:54,280 --> 00:48:56,200 And here's what he found. 1157 00:48:56,200 --> 00:48:58,830 The more activation there was in the amygdala-- 1158 00:48:58,830 --> 00:49:01,040 each square here is a different person-- 1159 00:49:01,040 --> 00:49:04,350 the more they remembered the emotional stuff. 1160 00:49:04,350 --> 00:49:06,110 But it didn't matter for neutral things. 1161 00:49:06,110 --> 00:49:07,820 So the amygdala seems unimportant for neutral 1162 00:49:07,820 --> 00:49:10,380 information, but the more it was engaged, the more they 1163 00:49:10,380 --> 00:49:11,690 remembered emotional information. 1164 00:49:11,690 --> 00:49:14,750 So this is sort of evidence in the typical human mind of a 1165 00:49:14,750 --> 00:49:17,090 relationship between the amygdala 1166 00:49:17,090 --> 00:49:18,750 and emotional memories. 1167 00:49:18,750 --> 00:49:23,200 So here's an experiment actually that we did at 1168 00:49:23,200 --> 00:49:25,540 Stanford, where we showed people stimuli that were 1169 00:49:25,540 --> 00:49:28,640 either neutral, somewhat negative-- and I'm going to 1170 00:49:28,640 --> 00:49:30,170 show you something that's very negative. 1171 00:49:30,170 --> 00:49:32,010 If you don't want to look, close your eyes for a moment. 1172 00:49:32,010 --> 00:49:32,310 Close your eyes. 1173 00:49:32,310 --> 00:49:33,200 Here we go. 1174 00:49:33,200 --> 00:49:33,840 Very negative. 1175 00:49:33,840 --> 00:49:34,660 OK. 1176 00:49:34,660 --> 00:49:37,390 Sorry. 1177 00:49:37,390 --> 00:49:39,220 It turns out if we don't show you something that negative, 1178 00:49:39,220 --> 00:49:41,200 it's hard to get your brain pumped up. 1179 00:49:41,200 --> 00:49:43,330 It doesn't have to be that sad, but it has 1180 00:49:43,330 --> 00:49:45,330 to be pretty intense. 1181 00:49:45,330 --> 00:49:46,680 So we show you things like this. 1182 00:49:46,680 --> 00:49:51,110 And we record your brain response for each of those. 1183 00:49:51,110 --> 00:49:52,590 And here's what we do. 1184 00:49:52,590 --> 00:49:54,450 We ask you to tell us how bad is this? 1185 00:49:54,450 --> 00:49:59,420 So the baby picture was bad for most people. 1186 00:49:59,420 --> 00:50:02,580 We wait three weeks, pretty long time, and then we test 1187 00:50:02,580 --> 00:50:05,310 your memory for the scenes from before. 1188 00:50:05,310 --> 00:50:08,190 We test your memory three weeks later, pretty long time. 1189 00:50:08,190 --> 00:50:09,050 And here's what we see. 1190 00:50:09,050 --> 00:50:10,890 Two things. 1191 00:50:10,890 --> 00:50:14,520 In the left amygdala in this study, here's what you rated 1192 00:50:14,520 --> 00:50:18,080 as terrible, pretty bad, somewhat bad, and neutral. 1193 00:50:18,080 --> 00:50:23,650 So the amygdala is responding to your subjective sense of 1194 00:50:23,650 --> 00:50:24,390 terribleness. 1195 00:50:24,390 --> 00:50:27,470 Now, we were really looking at arousal and negativity. 1196 00:50:27,470 --> 00:50:30,040 We didn't look at positive ones. 1197 00:50:30,040 --> 00:50:31,550 I can tell you in other studies-- 1198 00:50:31,550 --> 00:50:33,360 and here's a trick in research. 1199 00:50:33,360 --> 00:50:34,280 I'm going to tell you now-- 1200 00:50:34,280 --> 00:50:36,452 I only have a couple more slides, but I'm going to tell 1201 00:50:36,452 --> 00:50:38,660 you a little bit about insider things on imaging, just so you 1202 00:50:38,660 --> 00:50:41,660 understand imaging as as human and fallible a form of 1203 00:50:41,660 --> 00:50:43,860 research as anything, which you might suspect anyway. 1204 00:50:49,400 --> 00:50:51,555 So we show these things. 1205 00:50:51,555 --> 00:50:54,000 And we got these responses. 1206 00:50:54,000 --> 00:50:56,180 So that's going with your subjective sense of 1207 00:50:56,180 --> 00:50:58,050 how bad films are. 1208 00:50:58,050 --> 00:51:01,690 And then we tested people's memory, what we also found was 1209 00:51:01,690 --> 00:51:03,380 that memory was best when we got the 1210 00:51:03,380 --> 00:51:04,495 biggest amygdala response. 1211 00:51:04,495 --> 00:51:06,870 So that's just like you heard before. 1212 00:51:06,870 --> 00:51:11,240 So that all seemed find and lined up with a prior result. 1213 00:51:11,240 --> 00:51:13,950 But here was the slight surprise in the thing that 1214 00:51:13,950 --> 00:51:17,210 followed and that still gets cited fairly often. 1215 00:51:17,210 --> 00:51:18,790 It's the research that I've been affiliated with that 1216 00:51:18,790 --> 00:51:22,820 still gets cited most often in newspapers and magazines. 1217 00:51:22,820 --> 00:51:24,830 Anyway, so this was a study that you saw before. 1218 00:51:24,830 --> 00:51:26,670 And the thing I didn't emphasize to you was that this 1219 00:51:26,670 --> 00:51:28,695 was in the right amygdala, in the right hemisphere. 1220 00:51:28,695 --> 00:51:29,800 It doesn't really matter. 1221 00:51:29,800 --> 00:51:31,690 It just happened to be there. 1222 00:51:31,690 --> 00:51:34,450 Our study at Stanford was in the left hemisphere. 1223 00:51:34,450 --> 00:51:37,770 This is where we were getting the emotion memory responses. 1224 00:51:37,770 --> 00:51:41,410 And so we were very deep scientists. 1225 00:51:41,410 --> 00:51:43,750 And we said, what could be going on? 1226 00:51:43,750 --> 00:51:46,820 Why is Larry Cahill at UC Irvine getting 1227 00:51:46,820 --> 00:51:48,890 it in the left amygdala? 1228 00:51:48,890 --> 00:51:50,740 The more active it is, the more you would remember 1229 00:51:50,740 --> 00:51:51,570 emotional information. 1230 00:51:51,570 --> 00:51:54,690 And why is he getting it in the right amygdala and we're 1231 00:51:54,690 --> 00:51:56,700 getting it in the left? 1232 00:51:56,700 --> 00:51:59,110 So we took a piece of paper and we wrote down the 1233 00:51:59,110 --> 00:52:00,720 different things that people had found. 1234 00:52:00,720 --> 00:52:01,040 Oh. 1235 00:52:01,040 --> 00:52:02,400 The story I was going to tell you is about 1236 00:52:02,400 --> 00:52:03,360 Stephan Hamann's study. 1237 00:52:03,360 --> 00:52:06,650 So Stephan Hamann at Emory did a study where he said, OK. 1238 00:52:06,650 --> 00:52:08,940 All this amygdala response to negative things, does it also 1239 00:52:08,940 --> 00:52:11,360 respond to positive things? 1240 00:52:11,360 --> 00:52:12,590 That's a good question. 1241 00:52:12,590 --> 00:52:14,820 And the answer is yes. 1242 00:52:14,820 --> 00:52:17,110 But it turns out in many experiments it doesn't look 1243 00:52:17,110 --> 00:52:19,910 that way, because you saw, for those of you who looked at 1244 00:52:19,910 --> 00:52:22,270 that horrible-looking baby picture, what would be an 1245 00:52:22,270 --> 00:52:27,190 equal positive powerful picture? 1246 00:52:27,190 --> 00:52:27,920 Let's try this one. 1247 00:52:27,920 --> 00:52:30,510 Everybody agrees it's cute when there's little children 1248 00:52:30,510 --> 00:52:32,600 around a birthday cake. 1249 00:52:32,600 --> 00:52:35,290 Smile, she smiles. 1250 00:52:35,290 --> 00:52:38,230 Powerful, unless it's your kid, maybe. 1251 00:52:38,230 --> 00:52:40,730 Powerful image. 1252 00:52:40,730 --> 00:52:42,170 Powerful as the face of the infant? 1253 00:52:42,170 --> 00:52:42,840 No. 1254 00:52:42,840 --> 00:52:44,870 So it's a really interesting thing. 1255 00:52:44,870 --> 00:52:49,310 It's very hard to get positive stimuli that are as potent as 1256 00:52:49,310 --> 00:52:50,490 negative stimuli. 1257 00:52:50,490 --> 00:52:52,900 You can get a million negative stimuli from the internet and 1258 00:52:52,900 --> 00:52:55,530 it's very hard to get very positive ones. 1259 00:52:55,530 --> 00:52:57,560 Having said that, we said, let's just think about the 1260 00:52:57,560 --> 00:52:58,810 negative ones for the moment. 1261 00:52:58,810 --> 00:53:02,390 So our studies were fMRI, PET, PET. 1262 00:53:02,390 --> 00:53:04,260 Ours were all with women. 1263 00:53:04,260 --> 00:53:05,640 And these were all with men. 1264 00:53:05,640 --> 00:53:07,120 And you could go, well, why did that happen? 1265 00:53:07,120 --> 00:53:09,410 It's good that it's half women and half men, because these 1266 00:53:09,410 --> 00:53:12,160 were Positron Emission Tomography. 1267 00:53:12,160 --> 00:53:15,060 That involves injecting radioactive stuff into people 1268 00:53:15,060 --> 00:53:16,580 to do that kind of imaging. 1269 00:53:16,580 --> 00:53:20,420 And many IRBs say, well, let's not have women do it, because 1270 00:53:20,420 --> 00:53:22,350 they could be unknowingly pregnant. 1271 00:53:22,350 --> 00:53:23,710 They could be. 1272 00:53:23,710 --> 00:53:25,840 And we shouldn't be giving radioactive stuff just for an 1273 00:53:25,840 --> 00:53:27,250 experiment. 1274 00:53:27,250 --> 00:53:29,410 You could have debates about that, but that's the thought. 1275 00:53:29,410 --> 00:53:31,380 Why not let the men get their radioactive stuff? 1276 00:53:31,380 --> 00:53:34,940 We don't really need them. 1277 00:53:34,940 --> 00:53:36,980 Then so when we did this study, we said, well, these 1278 00:53:36,980 --> 00:53:37,640 were all with men. 1279 00:53:37,640 --> 00:53:39,620 It seems in fairness we should do it with women too. 1280 00:53:39,620 --> 00:53:41,770 We just thought that seemed fair, kind of. 1281 00:53:41,770 --> 00:53:44,030 We didn't have any big thought about that. 1282 00:53:44,030 --> 00:53:46,940 And again, we were getting left amygdala and they were 1283 00:53:46,940 --> 00:53:48,020 getting right amygdala. 1284 00:53:48,020 --> 00:53:50,060 Pictures or films, different. 1285 00:53:50,060 --> 00:53:52,430 And this caught our eye, that we had done 1286 00:53:52,430 --> 00:53:53,260 studies with women. 1287 00:53:53,260 --> 00:53:54,150 We were getting left amygdala. 1288 00:53:54,150 --> 00:53:56,040 They did it with men, with right amygdala. 1289 00:53:56,040 --> 00:53:58,820 So deep scientists that we were, Larry Cahill said, I'll 1290 00:53:58,820 --> 00:54:00,420 test men and women. 1291 00:54:00,420 --> 00:54:01,750 And we said, we'll test men and women. 1292 00:54:01,750 --> 00:54:02,950 And here's what we found. 1293 00:54:02,950 --> 00:54:05,780 And these are averages, but one critical thing that we 1294 00:54:05,780 --> 00:54:08,960 discovered-- we didn't know this-- is that to the extent-- 1295 00:54:08,960 --> 00:54:12,070 and these are averages, of course these are averages-- 1296 00:54:12,070 --> 00:54:15,270 that you compare men and women, on average women have 1297 00:54:15,270 --> 00:54:19,200 better memory for emotional life events, faster production 1298 00:54:19,200 --> 00:54:22,210 of autobiographical memories to cues, more accurate in 1299 00:54:22,210 --> 00:54:22,800 dating memories. 1300 00:54:22,800 --> 00:54:25,720 So these dating studies are pretty useful, because you 1301 00:54:25,720 --> 00:54:27,400 never know how accurate a person is when they have a 1302 00:54:27,400 --> 00:54:28,620 memory for something. 1303 00:54:28,620 --> 00:54:31,050 What they do in the dating studies is they have people 1304 00:54:31,050 --> 00:54:33,460 who are dating keep diaries, for 1305 00:54:33,460 --> 00:54:35,340 example, in the fall semester. 1306 00:54:35,340 --> 00:54:36,960 And presumably those are reasonably accurate. 1307 00:54:36,960 --> 00:54:39,050 They're filling them in every day. 1308 00:54:39,050 --> 00:54:42,130 And then things happen over the holidays and some people 1309 00:54:42,130 --> 00:54:43,960 remain dating and some don't. 1310 00:54:43,960 --> 00:54:45,890 So you go back to them in March, and you go, in your 1311 00:54:45,890 --> 00:54:49,480 fall, when the two of you were going out, tell us about what 1312 00:54:49,480 --> 00:54:50,400 you did in November. 1313 00:54:50,400 --> 00:54:52,850 And they can say who's more accurate. 1314 00:54:52,850 --> 00:54:55,480 And they have almost a virtual record, because they have the 1315 00:54:55,480 --> 00:54:58,500 responses that the men and women put down that day. 1316 00:54:58,500 --> 00:55:00,080 And on average-- these are averages-- the 1317 00:55:00,080 --> 00:55:01,370 women were more accurate. 1318 00:55:01,370 --> 00:55:02,940 And wives scored higher than husbands on vividness of 1319 00:55:02,940 --> 00:55:05,320 memories for first date, last vacation, recent argument. 1320 00:55:05,320 --> 00:55:06,740 So these are all averages. 1321 00:55:06,740 --> 00:55:09,440 There's lots of overlap, but an average is that way. 1322 00:55:09,440 --> 00:55:11,540 And so Larry Cahill went and did this thing. 1323 00:55:11,540 --> 00:55:14,710 And sure enough, again, as he found before, for men, the 1324 00:55:14,710 --> 00:55:16,800 more they turned on the right amygdala, the more certain 1325 00:55:16,800 --> 00:55:19,130 they were to remember negative films. 1326 00:55:19,130 --> 00:55:21,330 And for women, the more they turned on the left amygdala, 1327 00:55:21,330 --> 00:55:22,470 the more certain they would remember 1328 00:55:22,470 --> 00:55:24,240 negative films on average. 1329 00:55:27,030 --> 00:55:31,810 Now, the thing to know is, on average again, when you have 1330 00:55:31,810 --> 00:55:34,290 people rate the kinds of pictures we 1331 00:55:34,290 --> 00:55:37,330 use, how do you think-- 1332 00:55:37,330 --> 00:55:38,210 here it is. 1333 00:55:38,210 --> 00:55:40,690 This is one example where your stereotype guesses probably 1334 00:55:40,690 --> 00:55:42,810 play out for the averages. 1335 00:55:42,810 --> 00:55:46,660 Who rates this as more scary, or who says it's more scary, 1336 00:55:46,660 --> 00:55:48,710 men or women? 1337 00:55:48,710 --> 00:55:50,940 OK. 1338 00:55:50,940 --> 00:55:53,250 So positive or negative, I should say 1339 00:55:53,250 --> 00:55:54,620 for positive or negative. 1340 00:55:54,620 --> 00:55:56,860 Here's the women, not finding this a particularly-- 1341 00:55:56,860 --> 00:55:58,940 on average, and there's a range of responses-- 1342 00:56:01,540 --> 00:56:02,200 positive picture. 1343 00:56:02,200 --> 00:56:04,490 Here's men going, pretty cool. 1344 00:56:04,490 --> 00:56:06,110 What DVD did that come from? 1345 00:56:06,110 --> 00:56:10,290 So people are always asking, what does this really mean? 1346 00:56:10,290 --> 00:56:14,300 Are men just knowing they have to do this or whatever? 1347 00:56:14,300 --> 00:56:15,090 Who knows? 1348 00:56:15,090 --> 00:56:17,000 There's no answer to this about whether it's social 1349 00:56:17,000 --> 00:56:18,610 things or biology. 1350 00:56:18,610 --> 00:56:22,020 Certainly social things are a big part of the story. 1351 00:56:22,020 --> 00:56:24,100 When we have people rate the pictures in the scanner, 1352 00:56:24,100 --> 00:56:26,560 here's the women rating here's the worst pictures. 1353 00:56:26,560 --> 00:56:27,130 And look at the men. 1354 00:56:27,130 --> 00:56:29,940 They're less willing to rate these pictures as bad. 1355 00:56:29,940 --> 00:56:32,795 Again, psychologists who see these data say, well, maybe 1356 00:56:32,795 --> 00:56:35,610 the men think they're never supposed to rate them as bad, 1357 00:56:35,610 --> 00:56:37,610 because we're tough guys and nothing's so bad. 1358 00:56:37,610 --> 00:56:38,380 I mean, I don't know. 1359 00:56:38,380 --> 00:56:39,320 Who knows? 1360 00:56:39,320 --> 00:56:40,570 But this is the ratings. 1361 00:56:42,830 --> 00:56:44,830 Now, if we look at the activation of the men and 1362 00:56:44,830 --> 00:56:48,590 women on the left as they rate them, the worse they rate it, 1363 00:56:48,590 --> 00:56:51,140 the more intense they find it, the more they turned on their 1364 00:56:51,140 --> 00:56:51,970 left amygdala. 1365 00:56:51,970 --> 00:56:55,450 So at the moment they're rating them, men and women 1366 00:56:55,450 --> 00:56:57,510 look very similar. 1367 00:56:57,510 --> 00:56:59,840 But when we relate it to their memory, two things happen. 1368 00:56:59,840 --> 00:57:02,350 First, the women did have superior memory to the men. 1369 00:57:02,350 --> 00:57:04,010 These were Stanford undergraduates, probably not 1370 00:57:04,010 --> 00:57:07,440 that dissimilar on average to the people in this room. 1371 00:57:07,440 --> 00:57:12,200 And quite strikingly, as you saw it, activation in the 1372 00:57:12,200 --> 00:57:14,800 right hemisphere predicted memory in men, and the left 1373 00:57:14,800 --> 00:57:17,520 hemisphere for women. 1374 00:57:17,520 --> 00:57:19,750 So I know there's been a lot of right and left. 1375 00:57:19,750 --> 00:57:21,820 But here we think was the message. 1376 00:57:21,820 --> 00:57:24,490 And it's kind of stood the test of time a 1377 00:57:24,490 --> 00:57:27,310 little bit, on average. 1378 00:57:27,310 --> 00:57:30,480 What you see here is the part of the left amygdala turned on 1379 00:57:30,480 --> 00:57:32,120 for women as they're rating it. 1380 00:57:32,120 --> 00:57:34,550 The more intense, the more active. 1381 00:57:34,550 --> 00:57:36,880 In relation to whether they form a long term memory, the 1382 00:57:36,880 --> 00:57:38,580 more active, the more likely they'll remember it. 1383 00:57:38,580 --> 00:57:41,250 And kind of the physical overlap of the two. 1384 00:57:41,250 --> 00:57:45,970 In men, more active in that amygdala on the left during 1385 00:57:45,970 --> 00:57:47,350 the rating, but doesn't seem to be 1386 00:57:47,350 --> 00:57:50,460 involved in memory formation. 1387 00:57:50,460 --> 00:57:53,920 In the hippocampus, again, overlap, overlap, overlap. 1388 00:57:53,920 --> 00:57:55,860 No apparent overlap in the men. 1389 00:57:55,860 --> 00:57:58,590 So what happens literally in the brain, I mean, literally 1390 00:57:58,590 --> 00:58:00,890 as far as we can measure it, in women on average there was 1391 00:58:00,890 --> 00:58:03,860 more overlap between the parts of the brain engaged as you 1392 00:58:03,860 --> 00:58:06,460 evaluate something and the parts of the brain that make 1393 00:58:06,460 --> 00:58:08,470 the memory of that. 1394 00:58:08,470 --> 00:58:11,990 And in men, on average it was as if, here's my emotional 1395 00:58:11,990 --> 00:58:14,480 rating on the right, and here's what I'm going to 1396 00:58:14,480 --> 00:58:16,130 remember on the left. 1397 00:58:16,130 --> 00:58:18,150 Kind of a separation of those processes in 1398 00:58:18,150 --> 00:58:20,350 the most simple sense. 1399 00:58:20,350 --> 00:58:23,160 Now here's a huge question. 1400 00:58:23,160 --> 00:58:26,230 Does this brain imaging study tell us anything about whether 1401 00:58:26,230 --> 00:58:30,150 this is in the genes of boys and girls as they're born or a 1402 00:58:30,150 --> 00:58:32,430 consequence of socialization or both? 1403 00:58:35,320 --> 00:58:38,730 It's incredibly intuitive for people to think that if you 1404 00:58:38,730 --> 00:58:42,370 see it in the brain it's hardwired and genetic or 1405 00:58:42,370 --> 00:58:45,000 hormonal or something. 1406 00:58:45,000 --> 00:58:47,630 Brain imaging data never tells you that. 1407 00:58:47,630 --> 00:58:48,880 It never tells you that. 1408 00:58:48,880 --> 00:58:51,820 It just tells you by this age, this is what's going on. 1409 00:58:51,820 --> 00:58:54,680 And you don't have to know much psychology to know that 1410 00:58:54,680 --> 00:58:58,420 we're all hugely influenced to varying degrees, but we're all 1411 00:58:58,420 --> 00:59:01,750 hugely influenced by social influences on what it is to be 1412 00:59:01,750 --> 00:59:04,760 a male or a female in our families, in our cultures, in 1413 00:59:04,760 --> 00:59:06,690 our societies. 1414 00:59:06,690 --> 00:59:09,120 Whether something's in your genes or in your culture, it 1415 00:59:09,120 --> 00:59:11,160 shows up in your brain. 1416 00:59:11,160 --> 00:59:13,640 And we can't tell those two things apart. 1417 00:59:13,640 --> 00:59:15,780 Is this anything to do with how we're born? 1418 00:59:15,780 --> 00:59:20,630 Is this anything to do with how Hollywood pitches movies 1419 00:59:20,630 --> 00:59:27,320 that are about video game battles versus chick flicks, 1420 00:59:27,320 --> 00:59:28,930 how they're pitching that and trying to tell us we're 1421 00:59:28,930 --> 00:59:30,640 supposed to like something? 1422 00:59:30,640 --> 00:59:31,500 Who knows? 1423 00:59:31,500 --> 00:59:35,690 We can't tell if it's social or genetic at all.