For the most part, fMRI studies attempt to localize cognitive processes to specific regions in the brain. Popular media often introduce these studies with headlines that tout the discovery of “the brain region” for memory, language, empathy, moral reasoning, loving weiner schnitzel and so on.
These headlines can be terribly misleading, as they’re often misinterpreted to suggest a specific brain region is dedicated to a single function, when, in fact, any given function maps on to a network of regions (forming a circuit), while any given region is part of multiple circuits subserving many functions. Similar faux pas can be found in descriptions of the functions associated with genes, e.g. “The gene for (fill in the blank).”
A few years back, the NY Times ran an infamous piece featuring the work of a neuromarketing company. In a horrible experiment fit for The Onion, participants lay in the scanner while looking at pictures of then presidential candidates. Subjects showed increased amygdala activation to pictures of Mitt Romney, which researchers interpreted as a sign of anxiety.
But after watching Romney speak on video, the amygdala activity died down, which researchers said showed that voters’ anxiety had decreased.
Meanwhile subjects’ anterior cingulates lit up to pictures of Hillary Clinton.
Here’s how researchers interpreted this neural activity:
Emotions about Hillary Clinton are mixed. Voters who rated Mrs. Clinton unfavorably on their questionnaire appeared not entirely comfortable with their assessment. When viewing images of her, these voters exhibited significant activity in the anterior cingulate cortex, an emotional center of the brain that is aroused when a person feels compelled to act in two different ways but must choose one. It looked as if they were battling unacknowledged impulses to like Mrs. Clinton.
The Times article about the “research” was quickly and roundly criticized by prominent neuroscientists, 17 of whom quickly responded with a signed letter to the editor, which the Times ran a couple of days later:
To the Editor:
“This Is Your Brain on Politics” (Op-Ed, Nov. 11) used the results of a brain imaging study to draw conclusions about the current state of the American electorate. The article claimed that it is possible to directly read the minds of potential voters by looking at their brain activity while they viewed presidential candidates.
For example, activity in the amygdala in response to viewing one candidate was argued to reflect “anxiety” about the candidate, whereas activity in other areas was argued to indicate “feeling connected.” While such reasoning appears compelling on its face, it is scientifically unfounded.
As cognitive neuroscientists who use the same brain imaging technology, we know that it is not possible to definitively determine whether a person is anxious or feeling connected simply by looking at activity in a particular brain region. This is so because brain regions are typically engaged by many mental states, and thus a one-to-one mapping between a brain region and a mental state is not possible.As cognitive neuroscientists, we are very excited about the potential use of brain imaging techniques to better understand the psychology of political decisions. But we are distressed by the publication of research in the press that has not undergone peer review, and that uses flawed reasoning to draw unfounded conclusions about topics as important as the presidential election.
Adam Aron, Ph.D., University of California, San Diego
David Badre, Ph.D., Brown University
Matthew Brett, M.D., University of Cambridge
John Cacioppo, Ph.D., University of Chicago
Chris Chambers, Ph.D., University College London
Roshan Cools, Ph.D., Radboud University, Netherlands
Steve Engel, Ph.D., University of Minnesota
Mark D’Esposito, M.D., University of California, Berkeley
Chris Frith, Ph.D., University College London
Eddie Harmon-Jones, Ph.D., Texas A&M University
John Jonides, Ph.D., University of Michigan
Brian Knutson, Ph.D., Stanford University
Liz Phelps, Ph.D., New York University
Russell Poldrack, Ph.D., University of California, Los Angeles
Tor Wager, Ph.D., Columbia University
Anthony Wagner, Ph.D., Stanford University
Piotr Winkielman, Ph.D., University of California, San Diego
Undoubtedly, fewer people saw that letter than saw the original article, which was much more prominently displayed.
(By the above study’s logic, looking at a picture of Donald Trump should elicit activity in the anterior insula, a region often associated with disgust responses)
It’s unfortunate that the study received such a prominent platform for distribution because people, especially non scientists, can be heavily influenced by articles with pictures of brains or technical sounding neuro language. One study, which I’ve written about on the blog, found that people were much more likely to believe a nonsensical article if it had meaningless neuroscience language in it than if it didn’t. As the average lay person doesn’t possess the technical skills to distinguish between valid and invalid fMRI studies, it’s up to the scientific community to police itself, which it does a pretty good job of through the peer review process.
This next study I’ll talk about demonstrates some of the challenges inherent to mapping localized neural activity onto unseen mental processes; in this case, the subjective experience of intense, romantic long-term love.
Aaron and colleagues previously published a study that presented neural correlates of intense romantic love (2005). In brief, the study reported that regions in the reward circuit of the brain were activated in response to pictures of a lover (versus a close friend). In the current study, they wanted to explore if these findings could be extended to long-term married couples (couples together for more than 20+ years who report still being madly in love).
Participants lay in the scanner and were repeatedly presented with pictures from four different categories: their partner, a close friend, and both a highly familiar and low-familiar neutral acquaintance. They were instructed to think about “experiences with each stimulus person (that were) nonsexual in nature.”
The fMRI data was analyzed via subtraction, a common fMRI analysis method in which one condition is compared to another to see if any differences fall out. The contrast of interest was between the partner and the close friend. In a cognitive process sense, the only difference thought to exist between perceiving these two individuals was thought to be the subject’s romantic love for one and not for the other. So if neural activity in the close friend condition is subtracted from activity in the partner condition, whatever is left over should represent the neural substrate of romantic love.
Researchers found activation in the ventral tegmental area, substantia nigra and nucleus accumbens (and the hippocampus, which corresponded with reported sex frequency, but the effect seems to be driven largely by two outliers, one of whom reported they have sex almost every day).
The activity does suggest a classic reward response and replicates previous findings. However, the big question isn’t whether there is a response, but rather what’s driving it?
A valid fMRI study doesn’t only rely on the integrity or analysis of the fMRI data, but, also, and perhaps more importantly, on the experimental design. In order to attribute increased activation in one condition versus the other to a specific cognitive function, one must be confident they have created conditions that have cleanly isolated the independent variable of interest (romantic love). The ventral tegmental area and other regions in the basal ganglia have been repeatedly shown to encode reward value – that is, they respond to things that give us hedonic pleasure, such as food, drugs, sex or receiving money. Past work has shown that intense romantic love is associated with activity in the those regions (Aaron 2005). In the current study, activity in some neural regions previously associated with maternal pair bonding was shown (substantia nigra, for one). The authors hypothesized that neural correlates for romantic long-term love should encompass those associated with both intense romantic love and maternal pair bonding.
But this analysis is dependent on long-term, romantic love being the only difference between conditions that would explain the differences in brain activity. And that may not entirely be the case.
Just to refresh, the major dependent measure of interest was neural activity, especially of reward circuitry, while subjects looked at pictures of their long-term partner versus a close friend. One additional difference between these conditions (beyond romantic love) is that romantic partners are probably more familiar and closer to participants than close friends. This is a shortcoming acknowledged by the authors.
This difference suggests a causal chain of cognitive operations that could offer alternative explanations for some of the data seen in this study. First, It’s been shown that we prefer things that are familiar to us (the “mere exposure” effect, Zajonc, 1968). Second, we’re able to process familiar things (or people) much more fluently compared to the less familiar (Reber). Third, fluency processing has been associated with judgments of aesthetic appreciation such that the more fluently we can process something, the more beautiful or attractive we’re likely to rate it (Alter). Although the objective attractiveness of the photos was controlled for via a group of independent raters, the participants were likely much more subjective in their judgments and perhaps found their partners more attractive than an objective viewer might. Viewing attractive faces has been shown to elicit strong neural activity, particularly in the reward circuitry (NaCC and OFC).
Furthermore, it has been posited that people incorporate close others into their psychological construct of self. Recent studies (deGreck 2008) showed that regions active in a reward task, such as the bilateral ventral striatum, and the ventral tegmental area (VTA), are also involved in differentiating between high and low personal relevance.It seems that we find thinking about ourselves pretty damn rewarding! (We’re all at least a little bit narcissistic). To the extent that someone has been incorporated into our self concept, thinking about that person, or looking at their picture as in this study, could be correlated with responses in reward regions of the brain in part because they activate thoughts of ourselves.
Both the familiarity –> processing fluency –> attractiveness model and self relevant thinking are plausible alternative explanations for at least some of the neural correlates found in this paper.
One other potential area of concern is that there is no way of knowing that participants weren’t thinking about sex with their partners, even though they were told not to. This might be especially difficult to achieve, especially for the two outliers who reported almost daily sex. Regions active during sexual arousal include R. amygdala, hypothalamus, hippocampus, midbrain, mOFC and nucleus accumbens, many of which were found to be active in this study.
The neural activity measured here may very well reflect some aspect of individuals’ love for their partners. But there seem to be other possible explanations for some of the data. I suppose that’s why people call the study of consciousness, of which subjective experiences such as romantic love are a subset, the “hard problem.”
Acevedo BP, Aron A, Fisher HE, & Brown LL (2011). Neural correlates of long-term intense romantic love. Social cognitive and affective neuroscience PMID: 21208991
Aron, A., Fisher, H., Mashek, D., Strong, G., Li, H., Brown, L. (2005). Reward, motivation and emotion systems associated with early-stage intense romantic love. Journal of Neurophysiology, 93, 327–37.
DEGRECK, M., ROTTE, M., PAUS, R., MORITZ, D., THIEMANN, R., PROESCH, U., BRUER, U., MOERTH, S., TEMPELMANN, C., & BOGERTS, B. (2008). Is our self based on reward? Self-relatedness recruits neural activity in the reward system NeuroImage, 39 (4), 2066-2075 DOI: 10.1016/j.neuroimage.2007.11.006
Alter, A., & Oppenheimer, D. (2008). Easy on the mind, easy on the wallet: The roles of familiarity and processing fluency in valuation judgments Psychonomic Bulletin & Review, 15 (5), 985-990 DOI: 10.3758/PBR.15.5.985
Peskin, M., & Newell, F. (2004). Familiarity breeds attraction: Effects of exposure on the attractiveness of typical and distinctive faces Perception, 33 (2), 147-157 DOI: 10.1068/p5028
Reber, R., Schwarz, N., & Winkielman, P. (2004). Processing Fluency and Aesthetic Pleasure: Is Beauty in the Perceiver’s Processing Experience? Personality and Social Psychology Review, 8 (4), 364-382 DOI: 10.1207/s15327957pspr0804_3
The last few years have seen a calvacade of studies demonstrating that unexpected elements in the environment can unconsciously prime attitudes, beliefs and behaviors.
Just a few recent examples:
1. People are more likely to judge a person as “warmer” just after holding a warm (compared to a cold) cup (Williams & Bargh 2008a):
2. Job candidates whose resumes were seen on a heavy (versus light) clipboard were rated as better qualified for a job (Ackerman 2010)
3. The hotter the temperature is in a room or outside, the more likely people are to believe in global warming (Li 2011)
4. Working on a jigsaw puzzle with rough (versus smooth) pieces made people rate a subsequent personal encounter as “less smooth” (Ackerman 2010)
Based on the abundance of findings, there seems to be a robust market in unconscious priming.
Why do we see these kinds of effects? Yale psychologist and implicit cognition guru John Bargh said “… these (kinds of) demonstrations suggest a cognitive architecture in which social psychological concepts metaphorically related to physical-sensory concepts … are grounded in those physical concepts, such that activation of the physical version also activates (primes) the more abstract psychological concept.” What he’s describing is essentially conceptual metaphor theory, which originated with George Lakoff and Mark Johnson in the early 1980s. The theory suggests that cognition is largely based on metaphoric thinking, whereby the structure and logical protocols of one domain guides or structures thinking in another.
Aside from their theoretical contributions, these kinds of studies also provide a certain entertainment value in that they demonstrate associations between a given stimuli and an attitude or behavior that confounds our expectations.
A new study from University of New Mexico researchers presents yet another priming effect that can be added to the ever growing list. But this one ain’t for the kiddies.
In a nutshell: The study showed that the smell of poop, er, uh, fecal matter, (delivered in the form of a spray from a bottle of “Liquid Ass,” a novelty odor liquid) made participants more likely to report their intentions to use condoms in the near future. In other words, the smell of feces motivated safe sex attitudes. Although unpleasant to describe and probably even more so to have carried out, it does fit theoretically with a literature showing that pathogen avoidance/visceral disgust response can function as a mechanism to elicit unexpected effects on seemingly unrelated behaviors and attitudes. I recently discussed a study that looked at the flip side of the same coin. In this study, priming concerns about cleanliness made participants more likely to condemn a slightly immoral sex act and more likely to report conservative political attitudes (Subjects in the experimental condition were standing next to a soap dispenser).
While credit certainly has to be given for being able to work “Liquid Ass” into an experiment, I’m not sure that the researchers have shown pathogen-avoidance concern is the mechanism motivating subjects’ change in attitude.
For one, sufficient control questionnaires don’t seem to have been employed, asking participants to report attitudes in domains other than those in which pathogen avoidance plays a role. Perhaps the nasty scent mediated a more general shift in risk taking or impulsivity. Furthermore, self report is notoriously unreliable at predicting behavior; that is, participants’ answers might in part reflect self presentation concerns as much as shifts in attitude that would result in behavioral change. Finally, it’s possible that the general unpleasantness of the stimuli caused the shift in attitude and not it’s viscerally disgusting nature. One possible control could be an additional condition with an unpleasant, non-pathogen avoidance related stimuli from a different domain (e.g., an unpleasant noise).
Although it would be interesting to see if the effects would still hold up to these slight modifications, I don’t think I would want to be the one to run it…
Anderson ML (2010). Neural reuse: a fundamental organizational principle of the brain. The Behavioral and brain sciences, 33 (4) PMID: 20964882
Tybur JM, Bryan AD, Magnan RE, & Hooper AE (2011). Smells like safe sex: olfactory pathogen primes increase intentions to use condoms. Psychological science : a journal of the American Psychological Society / APS, 22 (4), 478-80 PMID: 21350181
Ackerman, J., Nocera, C., & Bargh, J. (2010). Incidental Haptic Sensations Influence Social Judgments and Decisions Science, 328 (5986), 1712-1715 DOI: 10.1126/science.1189993
Li Y, Johnson EJ, & Zaval L (2011). Local warming: daily temperature change influences belief in global warming. Psychological science : a journal of the American Psychological Society / APS, 22 (4), 454-9 PMID: 21372325
(*In honor of the upcoming NBA playoffs, a brief post on, for my money, the big paradox of professional basketball: the myth of the hot hand.)
Despite a long and fruitful career full of notable findings, Cornell psychologist Thomas Gilovich is perhaps most well known for a study he conducted with psychologists Amos Tversky and Robert Vallone 25 years ago when he presented a devastating debunking of the sports phenomena known as the “hot hand.”
The hot hand refers to the belief that success in basketball (and elsewhere) is self perpetuating. That is, a player can “get into a groove” after making a couple of shots such that making a shot leads to the higher likelihood of making the next shot. String together a bunch of these and you’ve got yourself a hot hand. Tune into any basketball game and you’ll inevitably hear an announcer say, “he’s in the zone” or “he can’t miss right now” about a player with a hot hand.
If this is true, one should look at a set of all made shots and all missed shots for some entity, such as one team for an entire year, and see that players made more shots after hits than they did after misses. Gilovich and his colleagues did just that, and that’s not what they found. They found that a player was just as likely to miss as make a shot after a previous make. But what about the possibility that opposing defense becomes tougher after a guy has made a few? Or what if he starts taking more difficult shots?
To control for these possibilties, they looked at free throws, which control for both of those factors in that there is no defensive pressure and shots are always taken from the same distance. A look at two seasons worth of free throws from the Boston Celtics showed second shots were completely independent of first shots. That is, if a player made the first free throw, he was no more likely to make the second one than if he missed the first one.
As a sports fan, I’ve always had a difficult time accepting this. (I’m not alone: the famed coach Bobby Knight responded to the study by saying, ” … there are so many variables involved in shooting the basketball that a paper like this really doesn’t mean anything.” Red Auerbach was even more blunt: “Who is this guy? So he makes a study? I couldn’t care less.” ) It just seems so counterintuitive that success or failure wouldn’t have some systematic effect on subsequent performance.
It’s a seeming truism that professional athletes (and performing artists, for that matter) perform best when they’re not thinking about how they’re playing. And it’s widely known by sports psychologists that thinking too much about one’s form in any given sport, whether it be shooting the basketball or attempting to sink a putt, can have deleterious effects on performance. So it seems plausible to imagine that success (or lack thereof) on the basketball court could alter one’s mental state in a way that could systematically alter performance. But, that’s not what the data says.
In the two decades plus since Gilovich, Vallone and Tversky’s seminal paper, the hot hand fallacy has been subject to a great deal of scrutiny and doubt, but the original finding has generally held up. One study controlled for time between shots but still found no evidence for the hot hand (Adams, 1992). Others have suggested that statistics are insufficient to handle the complexity of the game (Larkey, 1989). In 2009, John Huizinga from the Chicago Booth School of Business and Sandy Weil analyzed almost a million shots from 49 star players (unpublished; here for more details) and found, contrary to the existence of the hot hand, that NBA stars were more likely to miss after a made shot than after a miss. According to their analysis, this was more likely to happen after jump shots than non-jump shots (layups or dunks).
The implications of all this are that teams shouldn’t be looking to feed the ball to a guy just because he’s made a few in a row. But despite the ample support that hot hands don’t exist, you won’t have any easy time convincing many players or coaches of this.
A post game synopsis from an LA Lakers game last fall:
Jackson’s rationale for leaving Vujacic out entails the fact that Shannon Brown scored 16 points on six of nine shooting in 21 minutes. That led Jackson to “ride the hot hand,” as he called it, even if he had planned for Vujacic to defend against Houston guard Kevin Martin…
Even Phil Jackon, probably the most successful NBA coach in modern times, cites “the hot hand” as basis for his personnel decisions.
In Gilovich’s book summarizing the work, How We Know What Isn’t So, he talks to former NBA star World B. Free about the hot hand. “If I’m on, I find that confidence just builds . . . you feel nobody can stop you. It’s important to hit that first one, especially if it’s a swish. Then you hit another, and . . . you feel like you can do anything.”
This line of thinking, that success breeds success, is certainly feasible in many aspects of one’s life. Financial success can lead to further success, as profit can lead to more profit through increased capital. In one’s professional life, success can have a powerful effect on how one is perceived by others and promote increased success through an enhanced reputation. But, on the basketball court, the implications are quite clear. There are many factors that go into deciding – say, during crunch time of a close game – who should get the ball. A simple heuristic might be to give the ball to the guy with the highest shooting percentage. But what if he’s having an off night due to injury? Or being consistently double teamed? Perhaps your second best shooter gets the call. Many factors might inform the decision. But, according to everything the data is telling us, the “hot hand” should not be one of them.
GILOVICH, T. (1985). The hot hand in basketball: On the misperception of random sequences Cognitive Psychology, 17 (3), 295-314 DOI: 10.1016/0010-0285(85)90010-6
Adams, R. (1992). The “Hot Hand” Revisited: Successful Basketball Shooting as a function of intershot interval.Perceptual and Motor Skills, 74 (3) DOI: 10.2466/PMS.74.3.934-934
Larkey, P. D., Smith, R. A., & Kadane, J. B. (1989). It’s okay to believe in the ‘‘hot hand’’.
Chance: New Directions for Statistics and Computing, 2, 22 – 30.
The study previously summarized in this post was formally retracted in December 2011.
The retraction is the first in what is expected to be a slew of retractions of papers by lead author Diderik Stapel based entirely on falsified data.
Stapel was removed from his position at Tilburg University in November 2011 after an investigative committee at the university concluded he faked data on as many as dozens of papers over the past several years. Read a concise summary of how Stapel pulled this all off here.
Stapel’s mea culpa is below. Note that while his apology seems sincere, he can’t resist blaming his actions on the field itself, the pressure to publish often, etc. And he says he didn’t do it for selfish ends. Sorry buddy, but everyone else in the field is under the same pressure as you were but they don’t go around publishing papers based on fake data. They work their asses off and actually collect data (arguably the hardest part of the whole endeavor) before writing a study up and submitting it. What you did was for entirely selfish reasons. You did it to advance your career beyond what would have been possible if you played by the rules.
“I failed as a scientist. I adapted research data and fabricated research. Not once, but several times, not for a short period, but over a longer period of time. I realize that I shocked and angered my colleagues, because of my behavior. I put my field, social psychology in a bad light. I am ashamed of it and I deeply regret it.
… I think it is important to emphasize that I never informed my colleagues of my inappropriate behavior. I offer my colleagues, my PhD students, and the complete academic community my sincere apologies. I am aware of the suffering and sorrow that I caused to them.
… I did not withstand the pressure to score, to publish, the pressure to get better in time. I wanted too much, too fast. In a system where there are few checks and balances, where people work alone, I took the wrong turn. I want to emphasize that the mistakes that I made were not born out of selfish ends.”
UPDATE (2.26.2012): Tilburg University is conducting an investigation of Stapel’s entire body of work and won’t announce verdicts on specific studies until after the investigation in concluded.
Nice piece from the Boston Globe on the positive benefits of solitude. (My friend Adam Waytz, from the Harvard psychology department, gets a mention.)
Congenitally blind people use visual cortex to do language processing
An essay by June Carbone regards the role of neuroscience in determining punishment for adolescents who commit crimes such as murder. Focused on a recent US Supreme Court decision on the juvenile death penalty, the piece points out some of the limitations of applying neuroscientific findings to issues of jurisprudence.
A new study from researchers at Northeastern University says day traders make more money when they stay with the herd.
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- Drugging and Driving: Benzos, opioids and antidepressants and increased risk of driving accidents
- Social cognitive deficits in autism spectrum disorder
- Google crosses the web/brain barrier?
- Mortality among users of marijuana, cocaine, amphetamine, ecstasy and opioids
- The Neural Correlates of Romantic Love
- Name games
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