Increased striatal activation in response to unexpected positive feedback may represent a neurological brain marker for psychosis risk, suggests a study published online in Neuropsychopharmacology.
Psychosis is strongly associated with heightened levels of dopamine in the striatum, a brain region wired to process positive and negative feedback for learning, researchers explained. However, the neural consequences of this association are not fully understood.
For the study, researchers used functional magnetic resonance imaging (fMRI) on 21 participants at risk of psychosis, and 20 participants who served as controls, to gauge activation in the striatum when participants received unexpected feedback during a learning task.
Participants in the psychosis risk group, researchers found, showed striatal dysfunction compared with control subjects.
“This dysfunction is most evident when performing tasks where people need to learn from positive and negative feedback,” said John Kerns, PhD, psychology professor at the University of Missouri in Columbia. “For instance, we have found that the risk for psychotic disorders involves increased activation in the striatum for positive feedback, and negative feedback involves decreased activation in the same subregion of the brain.”
Enhanced activation to positive feedback, for example, may make an assumption seem more accurate than it is, while decreased activation to negative feedback may encourage the acceptance of inaccurate ideas.
Researchers are planning further investigation into the ability of fMRI to predict psychosis risk and whether preventive treatments may affect subsequent scans.
“Psychotic disorders like schizophrenia are often lifelong and disabling for individuals,” Dr. Kerns said. “These disorders have major public health and societal costs greater than cancer. A major goal of our current research is to understand the nature of psychosis risk so we can prevent years of suffering.”