Companies like “23andMe” have allowed us to have a little fun with personalized genomics. Spit in a cup and let our knowledge of genetic diseases and traits predict that which you may or may not know about yourself, they propose. A genetics professor in college once told my class that the ability to read out our personal genetic code is as useful as one of us trying to build and fly a Boeing 747 from blueprints; that is, blueprints aren’t everything.
Similarly, simple maps of our brains might be of no more value to us than a personality test or a pretty desktop background. But new technology is advancing the ways in which we can study, predict, and potentially therapeutically intervene in mental illness.
A recent study in Neuron used brain scans of nearly 50 prison inmates to explain how disturbances in certain brain circuits may translate into criminal behavior. Josh Buckholtz, senior author of the study and Associate Professor at Harvard, used mobile MRI scanners on the brains of inmates participating in a verbal delayed gratification test. The test asked whether the participant preferred to take less money now or more money later, if given the choice. Those who scored high for psychopathy showed greater activity in the ventral striatum, an area of the brain associated with evaluating subjective rewards. Buckholtz says,
So the more psychopathic a person is, the greater the magnitude of that response. That suggests the way they are calculating the value rewards is dysregulated, they may over-represent the value of an immediate reward [taking less money now rather than taking more money later].
As they mapped the connections between the ventral striatum to other regions known to be involved in decision-making, they found a possible explanation:
We found that connections between the striatum and the ventral medial prefrontal cortex were much weaker in people with psychopathy.
This portion of the prefrontal cortex is thought to provide one with the ability to envision future consequences for actions. We rely on the prefrontal cortex to evaluate our decision-making process and predict what may happen to us in when we act out a particular decision. Think of it as a computer program that maps out every possible move in a chess game, and every result associated with those moves. As you might imagine, a deficiency in this relay, resulting in a preference for immediate reward, could prompt one to make a bad decision (i.e. participate in criminal behavior).
Finally, this weakened striatum-to-cortex regulation was so pronounced that the group was able to accurately predict frequent convictions of crimes in the inmates studied.
An old way of thinking has left us with an incomplete understanding of how to approach mental health. The media does a poor job explaining mental health as a source of violent crime, and our justice system has not learned how to punish criminals who have obvious mental illnesses. So it is easy to see why we get trapped into blaming the wrong mechanisms.
However, a new wave of neuroscience research is challenging the long-standing idea that emotion drives behavior. Buckholtz’s study suggests that we turn instead to the choices that criminals make as a result of an imbalance in risk and reward, perpetuated by dysregulated brain circuitry. Once we identify deviations in neuronal signaling, we can start to predict behavior and attribute emotion:
If we can put this back into the domain of rigorous scientific analysis, we can see that psychopaths aren’t inhuman, they’re exactly what you would expect from humans who have this particular kind of brain wiring dysfunction.
These new technologies are not redrawing old blueprints. They are telling us that the blueprint has been there all along—we were just busy building the wrong plane.
Categories: In Research