The height of fashion: fMRI and high-impact publishing

Are some parts of the brain sexier than others?  Apparently there's no small amount of suspicion in fMRI labs that this is true, so Tim Behrens, neuroscientist at the Wellcome Trust Centre for Neuroimaging, University College London and the Functional MRI of the Brain Centre, University of Oxford and colleagues set out to answer this question.  Behrens talked about his study the other day with Quentin Cooper on BBC4's "Material World." The results were also published in the January Trends in Cognitive Sciences.  

You'd think all parts of the brain would be equally interesting, but apparently some labs are right to be suspicious that this isn't so. Behrens and colleagues analysed over 7000 brain imaging studies and concluded that some regions are indeed sexier than others, and studies of these regions tend to be published in higher impact journals than others.

Behrens et al. correlated the area of the brain subjected to fMRI in each of these 7000 papers with the impact factor of the journal in which the paper was published.

The champion of the popularity contest was the presupplementary motor area (pre-SMA), defeating its nearest contender, the dorsolateral prefrontal cortex, by the considerable margin of 25%. Further lowering the frequency threshold to ‘half-a-pre-SMA’ revealed a network of brain regions commonly activated in studies of attention and executive function, including the frontal operculum and/or insula, and the intraparietal sulcus. The only intruders on this cognitive panacea were the hand area of primary motor cortex and Broca’s area, both in the left hemisphere only.

As Behrens explained it to Cooper, the most fashionable region is the anterior insula, the part of the brain that seems to be associated with empathy.  Further, studies of the parts of the brain that are associated with, in Behrens' example, how you might fall in love are more inherently interesting and thus more likely to be published in a top-tier journal than a study of which part of the brain is involved in controlling, say, movement of your little finger.

Behrens and company were also able to identify the least fashionable parts of the brain.  

Leading the way in ignominy was the secondary somatosensory area (Z = 4.4, P < 5 x 10^-6), but the supplementary motor area was almost equally disgraced (Z = 4.25, P < 5 x 10^-6).  Researchers unfortunate enough to find activity in these regions can expect to be published in a journal with approximately half the impact of their most celebrated colleagues (mean impact factors of approximately 5 compared with approximately 9).

They also looked at keyword associations with impact factor.  Words like emotion, semantic, reward, recognition, attention, face, explicit, and recall clustered together, as did execution, fixation, vibrotactile, inhibition, stroop, saccades, covert and so on.  And, as the authors wrote, "We leave it to the reader to ... decide which set of words was positively correlated with impact factor, and which exhibited a negative correlation."

fMRI of the less sexy primary visual cortex, 

extrastriate visual cortex and lateral 

geniculate body; Wikimedia

Cooper tried to argue that some of this apparent fashionability might actually follow function.  Any kind of study of the human body, he suggested, would focus on the more significant functions.  The left side of the chest rather than the right side, e.g. But Behrens reminded him that it isn't just that there's more research into the big questions, which there is, but that it's primarily papers about some of the big questions that are published in the fashionable journals. Maybe, he suggested, because some are harder to sell to Radio 4. 

Indeed, there is a broader issue, which Cooper also pointed out, and that is that there are certainly funding fads.  "Nano-science," "climate change," "translational medicine," and so on are perhaps buzzwords that help your chances of funding and publication in top-tier journals.  There have been times when it has been best not to include the word "evolution" in your grant title.

But, who is setting the fashions and who is following?  Are journal editors, funding agencies, technological innovation the trendsetters?  Scientists themselves?  Is the idea to game the system? The rewards of publishing in top-tier journals are great, after all -- further funding, raises and promotions -- so, why not?  Anyone can do in their own field what Behrens et al. did with fMRI studies; figure out the key keywords and follow the money.  Some people surely will and do make their next grant decisions like this, maybe particularly in big money fields like genetics.

But, in fact, most people won't.  There were 7000 fMRI studies published, after all (whatever you think of the value of such work), most of them in lower tier journals, which means that a lot of people are interested in parts of the brain that are not fashionable (well, ok, fMRI itself is fashionable, in the fashionable field of neuroscience).  As long as there's money for a topic, someone's going to be studying it.  Some scientists must still be doing what they do for the love of the science.  Backwaters can have their appeal.  And scientists in those backwaters, self-selected to avoid the rapids as they are, might well be happier for it.