In a new article in Science, a group of researchers led by Geraint Rees from University College London, suggest they have a found a neural correlate for introspection. The region of interest is the anterior prefrontal cortex of the brain, which is also implicated in other higher cognitive behaviors like planning, decision-making, social intelligence, and determining predicted outcomes of one’s actions [it is the frontal cortex that was damaged in the infamous case of Phineas Gage].
“Introspection” was measured by having people answer a tough question, and subsequently measure how the result of their answer (right vs wrong) affected their confidence in their own decision making in a series of follow up questions. More introspection meant a correlation between the result of their early answers to their confidence in later ones; in a sense, introspection is the meta-analysis of one’s own thoughts. FMRI data showed that increased gray matter volume in the prefrontal cortex was correlated with high levels of introspection.