We're all psychopaths sometimes

A paper just published in the journal Brain reports that psychopathic individuals are less empathic than controls, but that empathy can be turned on on command.  The study is reported on the BBC website here. Researchers recorded fMRI images of 20 incarcerated males diagnosed as psychopaths and 26 non-prisoner controls as they watched video clips of hands interacting "in a loving, painful, neutral or rejecting way". The researchers report that the fMRI images are evidence that psychopathic individuals are less empathic than controls but that when they are encouraged to imagine what the actors in the videos were feeling, the active brain regions are more similar to those of the controls.

Experimental paradigm. (A) Three still frames from example videos of each condition. Each video included a receiving (1) and an approaching (2) hand. (B) Photo of hand interactions during the experience. (C) Design of the three experiments (always performed in this order). Source: Brain Vol 136, Issue 8, Pp 2550-2562

The researchers note that incarcerated psychopaths may not be representative of all psychopaths, and that the 20 subjects in their study were less educated and less wealthy than controls, and they can't be sure that these differences don't explain the differences observed between the two groups before the first were instructed to be empathetic.  And, the sample size is small.  Nonetheless they conclude that rather than having no empathy, as is apparently widely supposed, psychopaths simply have a 'reduced propensity' to empathize rather than an inability.  What 'reduced' means in other than some statistical value related to this particular study isn't clear, at least to us.

There are several interesting points here.  If it's true that people who have been thought to be unable to feel other people's pain actually can, this would mean that psychopathy is but a point on the spectrum of human affective behaviors, not to mention judgments we individually make about other people.  The ability to empathize is essentially distributed from none to total empathy, and as with blood pressure or height or blood glucose or many other traits, we (our culture or some assigned experts) define the extremes of the distributions, beyond some chosen value, as pathologies.

But it's not surprising that psychopaths, however defined, can switch on their empathy on command or under specific circumstances.  Few of us have equal amounts of empathy at all times -- we might identify more with someone we love than someone we dislike, or even cats more than dogs, if soldiers didn't turn off their empathy on the battlefield, they couldn't do their job, and we often listen to news about yet another war or famine in a far off place with no emotion.  Indeed, if the definition of psychopathy is lack of empathy, we're all psychopaths sometimes.

This study brings up many questions.  Can psychopathy be prevented?  Is it really a category?  Are psychopaths people who weren't taught empathy as children?  Will genes for psychopathy be sought, with the aim of identifying at-risk children and intervening (teaching empathy) before it's too late, and, disturbingly, where might that lead?  Is it ever too late, if even psychopaths who are hardened criminals can empathize on command?  Is the switchability something that we need to or will have studied for some assumed genetic basis?  If psychopaths can turn empathy on and off, what keeps them from turning it on more often? This seems to us to be the biggest challenge, no matter how clear it is that they can empathize.

We are not qualified to judge the degree to which fMRI is a modern form of phrenology with little in the way of rigorous underpinnings in circumstances like these, but there certainly are vocal skeptics about the usefulness of this new toy.  But it is likely that the much harder, if less glamorous slogging to work out the day-to-day behavior or behavior-changing approaches will take longer, and probably because they are more vague, the low-tech studies will struggle harder to get funding, and will get less news coverage.

The problem of understanding things like this, which we've said many times before, is that we don't know all of the potential triggers or vulnerabilities, inherent and environmental.  For that reason, even thinking of lifelong therapy, such as psychotropic drugging, is problematic.  Perhaps we just don't yet have the appropriate resesarch strategies, or even aren't asking the right kinds of questions.

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. 

Reading the thoughts of a dead salmon: a poignant tale

How do our brains translate sound waves into information about how far away the sound generator is from our ears?  The direction a sound is coming from is pretty easy to decipher because the sound hits our ears at different times; the difference is minute but enough for our brains to make sense of with respect to where the sound originates.  Distance is another question.  And what about soft-but-nearby vs loud-but-distant?  How does our brain distinguish between these two?

A Scientific American blog, The Scicurious Brain, posted on just this subject the other day, and we're happy it caught our eye.  Scicurious describes a new paper in PNAS by Kopco et al., "Neuronal representations of distance in human auditory cortex."  That is, it's basically an fMRI (functional magnetic resonance imaging) study of where activity happens in the brain when people hear sounds at different distances.

The researchers exposed 12 subjects to sounds of different intensities in a 'virtual reverberant environment', simulating sound coming from 15-100 cm away.  They conclude that neurons in a particular part of the brain (posterior nonprimary auditory cortices, that is a part of the brain already known to be involved in making sense of sound waves) are "sensitive to intensity-independent sound properties relevant for auditory distance perception".  I.e., this part of the brain determines the distance of a sound, at least within 100 centimeters.  How it does so is another question entirely.

fMRI results, Kopco et al.

So, this study doesn't really tell us a whole lot more than we knew before, and Scicurious points out that fMRI studies should be interpreted with caution.  Indeed, she says -- and this is why we love her post -- you can get fMRI signal from a dead fish.  Alas, that finding was reported in 2009 -- so sorry we didn't know about it until now!

Neuroscientist Craig Bennett purchased a whole Atlantic salmon, took it to a lab at Dartmouth, and put it into an fMRI machine used to study the brain. The beautiful fish was to be the lab’s test object as they worked out some new methods.

So, as the fish sat in the scanner, they showed it “a series of photographs depicting human individuals in social situations.” To maintain the rigor of the protocol (and perhaps because it was hilarious), the salmon, just like a human test subject, “was asked to determine what emotion the individual in the photo must have been experiencing."

If that were all that had occurred, the salmon scanning would simply live on in Dartmouth lore as a “crowning achievement in terms of ridiculous objects to scan.” But the fish had a surprise in store. When they got around to analyzing the voxel (think: 3-D or “volumetric” pixel) data, the voxels representing the area where the salmon’s tiny brain sat showed evidence of activity. In the fMRI scan, it looked like the dead salmon was actually thinking about the pictures it had been shown.

“By complete, random chance, we found some voxels that were significant that just happened to be in the fish’s brain,” Bennett said. “And if I were a ridiculous researcher, I’d say, ‘A dead salmon perceiving humans can tell their emotional state.’”

One readily criticizes seances and crystal balls, because we feel that conjuring is a scam rather than a science.  It is not possible to read someone else's thoughts, certainly not if they are among the dearly departed.  Or so we had thought.  Because if dead salmon can think, why not dead Aunt Mazie? 

We are not psychologists or neuroscientists, though we are scientists of a sort and we perhaps have a lot of nerve.  But we don't have enough nerve to challenge the usefulness of fMRI, not after universities have all bought their $1 Million instruments and boasted about how modern they now are.  We feel we should temper our tendency to think that salmon can't really have afterthoughts.  People have, we must admit, often reported 'near-death' experiences, but they weren't actually totally dead at the time!  But a salmon that was cold as a dead fish should not be sending out brain waves.  Of course we are assuming that there wasn't a short in the investigators' fMRI machine. An alternative of course is that there really is an afterlife, and its afterglow appears in the brain for a while--at least thinkers at seminaries should pay close attention to these startling findings.

We cannot personally attest to whether one can communicate with salmon by seance, because it has never crossed our minds to attempt it.  Nor have we any views on whether the cadavers of other fish (or amphibian) species might have similar postmortem brainwaves.  For the same reason, we must cease our glib assertions that "dead men tell no tales," and remain mute about your ability to get in touch with old Aunt Mazie.

Many many fMRI scans have been done since 2009 when the dead salmon results were publicized, so clearly dead fish thinking haven't dimmed researchers' enthusiasm for or faith in the method.  No test is perfect, and every test is at risk of yielding false positives or false negatives, and fMRIs are obviously no exception.   Nor are seances.  There are statistical corrections that can be made to fMRI results -- we don't know of any for seance results -- because fMRI readings have a lot of 'natural noise.'  But added to all the other caveats about fMRI's -- and the fact that whether or not we accept the fMRI findings about where in the brain we process information about how far away a sound is coming from, we still don't know how the brain does it -- we'll retain our skepticism about how much fMRI's can really tell us about ourselves.