Molly Crockett: Beware neuro-bunk

148,496 views ・ 2012-12-18

TED


Please double-click on the English subtitles below to play the video.

00:00
Translator: Joseph Geni Reviewer: Morton Bast
0
0
7000
00:16
I'm a neuroscientist, and I study decision-making.
1
16093
3877
00:19
I do experiments to test how different chemicals
2
19970
2307
00:22
in the brain influence the choices we make.
3
22277
3600
00:25
I'm here to tell you the secret to successful decision-making:
4
25877
6748
00:32
a cheese sandwich.
5
32625
2238
00:34
That's right. According to scientists, a cheese sandwich
6
34863
3660
00:38
is the solution to all your tough decisions.
7
38523
3622
00:42
How do I know? I'm the scientist who did the study.
8
42145
5057
00:47
A few years ago, my colleagues and I were interested
9
47202
2300
00:49
in how a brain chemical called serotonin
10
49502
2293
00:51
would influence people's decisions in social situations.
11
51795
3270
00:55
Specifically, we wanted to know how serotonin would affect
12
55065
3095
00:58
the way people react when they're treated unfairly.
13
58160
3815
01:01
So we did an experiment.
14
61975
1538
01:03
We manipulated people's serotonin levels by giving them
15
63513
3146
01:06
this really disgusting-tasting artificial lemon-flavored drink
16
66659
4623
01:11
that works by taking away the raw ingredient for serotonin
17
71282
3632
01:14
in the brain.
18
74914
1178
01:16
This is the amino acid tryptophan.
19
76092
2977
01:19
So what we found was, when tryptophan was low,
20
79069
2361
01:21
people were more likely to take revenge
21
81430
2452
01:23
when they're treated unfairly.
22
83882
3548
01:27
That's the study we did, and here are some of the headlines
23
87430
3823
01:31
that came out afterwards.
24
91253
2729
01:33
("A cheese sandwich is all you need for strong decision-making")
25
93982
2495
01:36
("What a friend we have in cheeses")
26
96477
2095
01:38
("Eating Cheese and Meat May Boost Self-Control") At this point, you might be wondering, did I miss something?
27
98572
3200
01:41
("Official! Chocolate stops you being grumpy") Cheese? Chocolate? Where did that come from?
28
101772
5395
01:47
And I thought the same thing myself when these came out,
29
107167
2133
01:49
because our study had nothing to do with cheese or chocolate.
30
109300
4245
01:53
We gave people this horrible-tasting drink
31
113545
2329
01:55
that affected their tryptophan levels.
32
115874
3202
01:59
But it turns out that tryptophan also happens to be found
33
119076
3681
02:02
in cheese and chocolate.
34
122757
2801
02:05
And of course when science says cheese and chocolate
35
125558
2310
02:07
help you make better decisions, well, that's sure to grab people's attention.
36
127868
4081
02:11
So there you have it:
37
131949
1967
02:13
the evolution of a headline.
38
133916
3507
02:17
When this happened, a part of me thought, well,
39
137423
2342
02:19
what's the big deal?
40
139765
2004
02:21
So the media oversimplified a few things, but in the end,
41
141769
3879
02:25
it's just a news story.
42
145648
2076
02:27
And I think a lot of scientists have this attitude.
43
147724
3353
02:31
But the problem is that this kind of thing happens all the time,
44
151077
3897
02:34
and it affects not just the stories you read in the news
45
154974
3127
02:38
but also the products you see on the shelves.
46
158101
2779
02:40
When the headlines rolled, what happened was,
47
160880
2667
02:43
the marketers came calling.
48
163547
2826
02:46
Would I be willing to provide a scientific endorsement
49
166373
3219
02:49
of a mood-boosting bottled water?
50
169592
3261
02:52
Or would I go on television to demonstrate,
51
172853
2144
02:54
in front of a live audience,
52
174997
1025
02:56
that comfort foods really do make you feel better?
53
176022
3599
02:59
I think these folks meant well, but had I taken them up on their offers,
54
179621
3961
03:03
I would have been going beyond the science,
55
183582
2374
03:05
and good scientists are careful not to do this.
56
185956
3257
03:09
But nevertheless, neuroscience is turning up more and more in marketing.
57
189213
4368
03:13
Here's one example: Neuro drinks,
58
193581
2560
03:16
a line of products, including Nuero Bliss here,
59
196141
3241
03:19
which according to its label helps reduce stress,
60
199382
2901
03:22
enhances mood, provides focused concentration,
61
202283
3426
03:25
and promotes a positive outlook.
62
205709
2688
03:28
I have to say, this sounds awesome. (Laughter)
63
208397
4625
03:33
I could totally have used this 10 minutes ago.
64
213022
3876
03:36
So when this came up in my local shop, naturally I was
65
216898
3430
03:40
curious about some of the research backing these claims.
66
220328
3549
03:43
So I went to the company's website looking to find
67
223877
2926
03:46
some controlled trials of their products.
68
226803
3426
03:50
But I didn't find any.
69
230229
1677
03:51
Trial or no trial, these claims are front and center
70
231906
3738
03:55
on their label right next to a picture of a brain.
71
235644
3962
03:59
And it turns out that pictures of brains have special properties.
72
239606
5703
04:05
A couple of researchers asked a few hundred people
73
245309
2462
04:07
to read a scientific article.
74
247771
2691
04:10
For half the people, the article included a brain image,
75
250462
3327
04:13
and for the other half, it was the same article
76
253789
1863
04:15
but it didn't have a brain image.
77
255652
2704
04:18
At the end — you see where this is going —
78
258356
1632
04:19
people were asked whether they agreed
79
259988
2110
04:22
with the conclusions of the article.
80
262098
3322
04:25
So this is how much people agree with the conclusions
81
265420
2273
04:27
with no image.
82
267693
1913
04:29
And this is how much they agree with the same article
83
269606
3647
04:33
that did include a brain image.
84
273253
2767
04:36
So the take-home message here is,
85
276020
1949
04:37
do you want to sell it? Put a brain on it.
86
277969
4907
04:42
Now let me pause here and take a moment to say that
87
282876
2113
04:44
neuroscience has advanced a lot in the last few decades,
88
284989
3698
04:48
and we're constantly discovering amazing things
89
288687
2453
04:51
about the brain.
90
291140
1273
04:52
Like, just a couple of weeks ago, neuroscientists at MIT
91
292413
3144
04:55
figured out how to break habits in rats
92
295557
2800
04:58
just by controlling neural activity in a specific part of their brain.
93
298357
3993
05:02
Really cool stuff.
94
302350
1590
05:03
But the promise of neuroscience has led to some really
95
303940
3293
05:07
high expectations and some overblown, unproven claims.
96
307233
5236
05:12
So what I'm going to do is show you how to spot
97
312469
3039
05:15
a couple of classic moves, dead giveaways, really,
98
315508
3546
05:19
for what's variously been called neuro-bunk,
99
319054
2796
05:21
neuro-bollocks, or, my personal favorite, neuro-flapdoodle.
100
321850
5692
05:27
So the first unproven claim is that you can use brain scans
101
327542
4338
05:31
to read people's thoughts and emotions.
102
331880
3912
05:35
Here's a study published by a team of researchers
103
335792
3047
05:38
as an op-ed in The New York Times.
104
338839
2833
05:41
The headline? "You Love Your iPhone. Literally."
105
341672
4245
05:45
It quickly became the most emailed article on the site.
106
345917
4450
05:50
So how'd they figure this out?
107
350367
2169
05:52
They put 16 people inside a brain scanner
108
352536
3028
05:55
and showed them videos of ringing iPhones.
109
355564
3282
05:58
The brain scans showed activation in a part of the brain
110
358846
3462
06:02
called the insula, a region they say
111
362308
2652
06:04
is linked to feelings of love and compassion.
112
364960
3784
06:08
So they concluded that because they saw activation in the insula,
113
368744
3660
06:12
this meant the subjects loved their iPhones.
114
372404
4287
06:16
Now there's just one problem with this line of reasoning,
115
376691
2144
06:18
and that's that the insula does a lot.
116
378835
3516
06:22
Sure, it is involved in positive emotions
117
382351
2305
06:24
like love and compassion,
118
384656
2342
06:26
but it's also involved in tons of other processes,
119
386998
2673
06:29
like memory, language, attention,
120
389671
3073
06:32
even anger, disgust and pain.
121
392744
4036
06:36
So based on the same logic, I could equally conclude
122
396780
4463
06:41
you hate your iPhone.
123
401243
2453
06:43
The point here is, when you see activation in the insula,
124
403696
2844
06:46
you can't just pick and choose your favorite explanation
125
406540
3026
06:49
from off this list, and it's a really long list.
126
409566
4666
06:54
My colleagues Tal Yarkoni and Russ Poldrack
127
414232
2334
06:56
have shown that the insula pops up in almost a third
128
416566
3122
06:59
of all brain imaging studies that have ever been published.
129
419688
4736
07:04
So chances are really, really good
130
424424
1514
07:05
that your insula is going off right now,
131
425938
3126
07:09
but I won't kid myself
132
429064
1622
07:10
to think this means you love me.
133
430686
3677
07:14
So speaking of love and the brain,
134
434363
2907
07:17
there's a researcher, known to some as Dr. Love,
135
437270
3865
07:21
who claims that scientists have found the glue
136
441135
3485
07:24
that holds society together,
137
444620
2647
07:27
the source of love and prosperity.
138
447267
3776
07:31
This time it's not a cheese sandwich.
139
451043
2189
07:33
No, it's a hormone called oxytocin.
140
453232
3857
07:37
You've probably heard of it.
141
457089
1867
07:38
So, Dr. Love bases his argument on studies showing
142
458956
2892
07:41
that when you boost people's oxytocin,
143
461848
2945
07:44
this increases their trust, empathy and cooperation.
144
464793
4173
07:48
So he's calling oxytocin "the moral molecule."
145
468966
4080
07:53
Now these studies are scientifically valid,
146
473046
2842
07:55
and they've been replicated, but they're not the whole story.
147
475888
4136
08:00
Other studies have shown that boosting oxytocin
148
480024
2713
08:02
increases envy. It increases gloating.
149
482737
4743
08:07
Oxytocin can bias people to favor their own group
150
487480
3316
08:10
at the expense of other groups.
151
490796
3092
08:13
And in some cases, oxytocin can even decrease cooperation.
152
493888
4252
08:18
So based on these studies, I could say oxytocin
153
498140
3820
08:21
is an immoral molecule, and call myself Dr. Strangelove.
154
501960
4751
08:26
(Laughter)
155
506711
3360
08:30
So we've seen neuro-flapdoodle all over the headlines.
156
510071
4110
08:34
We see it in supermarkets, on book covers.
157
514181
2778
08:36
What about the clinic?
158
516959
2671
08:39
SPECT imaging is a brain-scanning technology
159
519630
3415
08:43
that uses a radioactive tracer
160
523045
2069
08:45
to track blood flow in the brain.
161
525114
3040
08:48
For the bargain price of a few thousand dollars,
162
528154
3084
08:51
there are clinics in the U.S. that will give you
163
531238
4118
08:55
one of these SPECT scans and use the image
164
535356
3453
08:58
to help diagnose your problems.
165
538809
2637
09:01
These scans, the clinics say, can help
166
541446
2529
09:03
prevent Alzheimer's disease,
167
543975
2902
09:06
solve weight and addiction issues,
168
546877
2464
09:09
overcome marital conflicts,
169
549341
2672
09:12
and treat, of course, a variety of mental illnesses
170
552013
3150
09:15
ranging from depression to anxiety to ADHD.
171
555163
3579
09:18
This sounds great. A lot of people agree.
172
558742
2570
09:21
Some of these clinics are pulling in tens of millions
173
561312
2166
09:23
of dollars a year in business.
174
563478
3304
09:26
There's just one problem.
175
566782
2084
09:28
The broad consensus in neuroscience
176
568866
2677
09:31
is that we can't yet diagnose mental illness
177
571543
3185
09:34
from a single brain scan.
178
574728
2783
09:37
But these clinics have treated
179
577511
2231
09:39
tens of thousands of patients to date,
180
579742
2440
09:42
many of them children,
181
582182
1762
09:43
and SPECT imaging involves a radioactive injection,
182
583944
3478
09:47
so exposing people to radiation, potentially harmful.
183
587422
5997
09:53
I am more excited than most people, as a neuroscientist,
184
593419
3114
09:56
about the potential for neuroscience to treat mental illness
185
596533
4281
10:00
and even maybe to make us better and smarter.
186
600814
4724
10:05
And if one day we can say that cheese and chocolate
187
605538
2700
10:08
help us make better decisions, count me in.
188
608238
4304
10:12
But we're not there yet.
189
612542
2576
10:15
We haven't found a "buy" button inside the brain,
190
615118
3735
10:18
we can't tell whether someone is lying or in love
191
618853
3698
10:22
just by looking at their brain scans,
192
622551
3383
10:25
and we can't turn sinners into saints with hormones.
193
625934
4264
10:30
Maybe someday we will, but until then,
194
630198
2204
10:32
we have to be careful that we don't let overblown claims
195
632402
2843
10:35
detract resources and attention away from the real science
196
635245
3386
10:38
that's playing a much longer game.
197
638631
3759
10:42
So here's where you come in.
198
642390
2438
10:44
If someone tries to sell you something with a brain on it,
199
644828
3171
10:47
don't just take them at their word.
200
647999
2879
10:50
Ask the tough questions. Ask to see the evidence.
201
650878
3246
10:54
Ask for the part of the story that's not being told.
202
654124
3898
10:58
The answers shouldn't be simple, because the brain isn't simple.
203
658022
5088
11:03
But that's not stopping us from trying to figure it out anyway.
204
663110
4495
11:07
Thank you. (Applause)
205
667605
4000

Original video on YouTube.com
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7