Research note: Scientists look for the source of rigid thinking
Rigid thinking — or an inability to adapt to new information in the environment — is a hallmark of schizophrenia and depression. Now a Yale team headed by Alex Kwan from the Department of Psychiatry provides some insights into what happens in the brain when flexible thinking is required. Using fluorescent sensors to monitor brain activity in living mice, the team noted distinct patterns of activity in the premotor cortex when mice were confronted with different situations. If confronted with familiar situations that favor internally guided action — the human equivalent of looking left automatically when crossing the street in the United States — activity change was gradual and late. However in demanding situations that call for heeding sensory cues — watching and listening for cars in unfamiliar country — neural activity pattern shifts abruptly and early, even before a behavior change. The changes were observable at the level of ensembles of individual brain cells, as seen in neurons firing in the accompanying movie. “Plausibly, the cognitive rigidity characteristic of disorders such as schizophrenia could result from an inability of frontal cortical networks to shift or maintain stable ensemble states,” the authors note. The findings were published July 11 in the journal Nature Neuroscience.