An article soon to be published in the Journal of Cognitive Neuroscience states that children of low socioeconomic status show brain activity similar to that of stroke patients. Scientists from the University of California, Berkeley examined normal, healthy 9- and 10-year-olds with an electroencephalograph (EEG) and found that children from low income families had prefrontal cortex (PFC) damage typically seen in adults who had suffered a stroke. The researchers are not the first to note PFC deficiencies in socioeconomically disadvantaged children. However, previous studies examined brain function indirectly, by having subjects complete various tasks. Lead author Mark Kishiyama notes, “Our study is the first with direct measure of brain activity where there is no issue of task complexity.” The children in the study watched triangles flash on a screen and had to press a button when they saw a triangle. Children from lower income families had more difficulty ignoring distractions.

Like stroke patients, the poorer children had less activity in their PFCs. The researchers note that this problem is not necessarily irreversible. At age 3, disadvantaged children have half the vocabulary of middle income 3 year olds and by age 4, they have heard 30 million fewer words. The authors suggest that PFC performance can be improved by talking to children more. This research seems likely to increase support for HeadStart and similar programs.

What I find most interesting about this research, is that the PFC activity was similar to that of stroke patients, who sometimes become violent after their stroke. Perhaps people who do not want to spend money on early childhood education programs may change their mind if they see that these programs may prevent violence later on.

Recently, the journal Biological Psychology published an article about brain responses to violence in youths with aggressive conduct disorder (CD).  On Nov. 12, it was the topic of a blog entry on the New York Times‘s website and on Nov. 18, Slate attacked both the blog and the original study. I read these three items in the opposite order that I should have. The reasonable thing to do would have been to start with the journal article to form my own impressions, then read the Times blog, and finally read the Slate article.

However, I came across the Slate article, written by Daniel Engber, first and found it convincing until I read the original article. I agree with Engber’s first two main points. The participants in the study, who exhibited signs of aggression including “starting fights; bullying using a weapon; theft with confrontation of the victim; physical cruelty to people; cruelty to animals and forced sex” should not simply be called bullies. (Although Engber shows a bit of bad science on his part in suggesting that these youths with CD should be called sociopaths- the Biol. Psych. article points out that CD is a precursor to Antisocial Personality Disorder, not a synonym for it). His second point is “the ‘aggressive youths’ never inflicted any pain (real or imagined) on other people during the experiment. Whatever enjoyment or dismay they felt came from viewing a set of photographs depicting, for example, someone stepping on somebody else’s toe. So the brain-imaging data may tell us what it’s like to watch a bully but not necessarily what it’s like to be a bully.”

To be fair, I also agree with his third argument “the brain scans themselves are open to interpretation,” but unlike him, I don’t think this is a downside of the study. Of course brain scans are open to interpretation. All science is and should be open to interpretation. This doesn’t make the study “iffy” or “questionable” as Engber describes it. The researchers also aren’t shy about this fact. Among other admissions, they write, “There are important reasons to be cautious when interpreting the activation of the striatum as indicating a positive affect response to viewing others in pain, however…In humans, the striatum is activated by stimuli associated with reward, but also by salient aversive, novel, and intense stimuli.”

Engber writes, “Let’s pretend there were some good reason to wonder how much fulfillment a bully finds in his daily wedgies. The University of Chicago research wouldn’t help, even if we cared to know.” The reason why it might not help is because that wasn’t the point of the study. The goal was to determine if youths with CD “exhibit atypical empathic responses to viewing others in pain.” The findings were complicated, and in some cases, conflicted with previous studies. For instance, the researchers found no reduced amygdala responses in subjects with CD, in contrast to previous studies.

So why does this subpar journalism matter? It’s because one day (if it hasn’t happened already) some lawyer will show jurors a brain scan and try to convince them that it proves the defendant either enjoys or doesn’t enjoy others’ pain. Normally, I would think that a juror who had read about a neuroscience study like this one in Slate or the Times would be well-informed about it and able to make a reasonable decision. Unfortunately, that’s not true in this case.

On June 12, 24-year old Aditi Sharma and her boyfriend Pravin Khandelwal were convicted of the murder of Sharma’s ex-fiancé Udit Bharati.  Their trials marked the first time brain scans presented as evidence of a defendant’s knowledge of a crime led to a conviction. The lie detection test, the Brain Electrical Oscillations Signature test, or BEOS, was created by Champadi Raman Mukundan, the former director of the psychology department at the National Institute of Mental Health and Neuro Sciences (NIMHANS) in Bangalore, India. The Indian media praised the use of this technology—the Times of India called BEOS a “forensic tool” the “state police can now bank on…to achieve speedy convictions” and declared “the findings clearly indicated their [Sharma and Bharati’s] involvement in the murders”—but neuroscientists in India and elsewhere were wary.

Unlike traditional polygraph tests, which detect lies through indirect means such as heart rate and skin conduction measurements, the BEOS test is meant to directly show brain activity. A suspect is read a series of statements that should only trigger memories in someone who actually took part in the events. For example, Sharma was read the statement “I bought arsenic.” Mukundan claims that experiential memories triggered by such statements can be visualized on brain scans and provide evidence of guilt, but a six-member committee led by the current head of NIMHANS called BEOS “unscientific“.

Other evidence against Sharma and Khandelwal was used, such as polygraph tests, but they insist they are innocent. Mukundan claims that the BEOS error rate is only 5% but his work has not been independently verified and has never been published in a peer-reviewed journal. Few specifics about his methodology are available and it remains unclear how he determined that error rating and if it is reliable for all suspects. His test depends on the detection of experiential memories, and since children often cannot accurately recall how they received certain information (whether they learned it themselves through experience or whether they were told it) it seems plausible that this test will not be accurate for people with certain mental defects. Exactly how sensitive the test is also needs to be explored. Could someone who has repeatedly imagined killing someone but not actually done it be falsely accused on the basis of this test? What if someone has dreamed of committing a crime?  However, the most disturbing thing about the use of this test is not that it might not be 100% accurate- it is that judges who allowed the tests to be used ignored the consensus of experts and used evidence that as nonscientists, they cannot fully understand.