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When good science goes bad: fMRI and neuropolitics

August 12, 2013 0 Comments

(This post comes from a long time ago, July 5, 2008, but represents some issues that are still relevant today, including the important problem of reverse inference.)

rep&demo_brainsEventually the chickens come home to roost.  Or insert your favorite aphorism here.  It looks like a full backlash is officially underway regarding some of the more, shall we say, inventive uses of fMRI to peer into people’s brains while they’re thinking about stuff – especially political stuff like Presidential candidates and world peace.

It all started last November when Marco Iacoboni, a respected neuroscientist at UCLA, and several colleagues published an op ed piece in the New York times called “This is your brain on politics“.  They scanned 20 people’s brains in an fMRI machine while the people watched images and videos of Presidential candidates.  Then they made several inferences about what their participants were thinking based on what areas of their brains were lighting up in the fMRI images.  They observed, for example, that “emotions about Hillary Clinton are mixed” and “John Edwards has promise – and a problem”, the problem being that he appeared to light up the insula for some people, “an area associated with disgust and other negative feelings”.

This relatively innocent exercise in neural tea-leaf reading was almost immediately met by a major hand-slapping  from 17 (count ‘em!) leading neuroscientists, who wrote in a letter-to-the-editor three days later:

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.

So, I guess John Edwards needn’t worry after all, those lit-up insuli don’t necessarily mean he’s disgusting. (His problems with disgust came later.)

That might have been the end of it, but the controversy got picked up and echoed throughout the blogosphere, and suddenly we were seeing posts with titles like:

Somebody hit a nerve.  You would think that Prof. Iacoboni and his friends would get the hint, but their willingness to chat up the media appears to be undeterred, because they recently showed up again in an article in The Atlantic entitled “My Amygdala, My Self“, in which the author avails himself of an fMRI scan to see what his brain is really telling him.

I thought the article was a great tongue-in-cheek romp, but I got a sense that maybe the scientists weren’t in on the joke.  When Goldberg, a devout Jew, sees his ventral striatum (a “reward center”) light up when viewing a picture of the Premier of Iran, Mahmoud Ahmadinejad, Prof. Iacoboni throws up his hands.

“Reward!” Iacoboni said. “You’ll have to explain this one.”

But Iacoboni’s colleague, sensing a vacuum, rushes in to provide possibly the greatest post hoc explanation ever to grace the pages of  The Atlantic:

Joshua Freedman, who is a practicing psychiatrist, offered a possible explanation: “Perhaps you believe that the Israelis or the Americans have the situation under control and so you’re anticipating the day that he’s brought down.” He asked me some questions about my view of Jewish history, and then said: “You seem to believe that the Jewish people endure, that people who try to hurt the Jewish people ultimately fail. Therefore, you derive pleasure from believing that Ahmadinejad will also eventually fail. It’s very similar to the experiment with the monkey and the grape. It’s been shown that the monkey feels maximal reward not when he eats the grape but at the moment he’s sure it’s in his possession, ready to eat. That could explain your response to Ahmadinejad.”

Not surprisingly, some folks took umbrage with the whole exercise, and the blog post titlists emerged in full glory:

Poor Jeffrey Goldberg.  As Mr. T might say, “I pity the journalist who walks into the middle of an academic food-fight.”

But the serious side of the debate subsequently resurfaced in an exchange between Prof. Iacoboni and Prof. Russell Poldrack over on Adam Kolber’s Neuroethics & Law Blog.

Iacoboni responds to his “neuropolitics” critics here, and Poldrack responds to the response here.  The debate revolves around two points.  The first has to do with the role of the amygdala in emotional processing, specifically, whether amygdala activation is more likely to be associated with positive or negative emotions.  Iacoboni makes the rather amazing claim that amygdala activation is more likely to represent positive emotion because there are more articles published that show amygdala activation during positive emotions.  Poldrake takes that apart pretty easily.

The second point has to do with a much more consequential issue, called the reverse inference problem.  One way to put it is like this:  If I get you to experience a positive emotion and your amygdala lights up, does that mean that when your amydgala lights up you are experiencing a positive emotion?  The logical answer, of course, is no.  “If A, then B” does not imply “If B, then A.”  It only logically implies “If not-B, then not-A”.  But other factors can affect your willingness to take a chance on “if B, then A” … for example, whether anyone has ever seen B in the absence of A, or how many times they have seen A and B together.

This is actually a very important topic for applied neuroscience, so I’m going to save that discussion of another day. (It only took me five years … reverse inference is covered at length in Neuromarketing for Dummies.)

Originally posted on my previous blog on July 5, 2008. Slilghtly edited.

About the Author:

AvatarSteve is a writer, speaker, researcher, and marketing consultant. He is author of Intuitive Marketing (2019), a study of persuasion and influence in marketing theory and practice, and co-author of Neuromarketing for Dummies (2013), a comprehensive overview of neuromarketing science, applications, methodologies, and ethics. He is Managing Partner at Intuitive Consumer Insights, where he focuses on marketing education and consulting.

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