( heir way to a specified goal. Functiona...)Where we change our mind

Importantly, Yoshida and Ishii used sophisticated statistical probabilistic analysis of the subjects' movements to overcome a major obstacle to such studies. That obstacle is that the beliefs of the subjects during the experiment could not be determined unequivocally; thus, those beliefs could not be correlated with brain function.

However, the researchers' statistical analysis of the subject's navigation decisions enabled them to infer which of two "cognitive states" the subject was in, to give the researchers insight into which cortical regions were active during the states. One such cognitive state was a belief about where the subject was in the maze, and the other was a set of "operant" states. These operant states were a "proceed or update mode" or a "reevaluate or back-track mode."

Analyzing the brain regions active during these states, Yoshidi and Ishii pinpointed which regions of the subjects' cerebral cortex were active during the different processes involved in "changing their minds." Specifically, the researchers found that "belief maintenance" processes are performed principally by a region called the anterior prefrontal cortex, and "belief back-track" processes occur in the medial prefrontal cortex.

"Our results provide evidence that activity in different regions of the prefrontal cortex reflect critical computational components involved in decision making in uncertain environments," concluded the researchers. "This fits well with the proposed role of these regions in decision making, which is likely to be crucial in complex real-world environments. We also illustrate the utility of statistical model-based inference and regression in delineating key task parameters that may be represented in spatially distinct brain regions," they concluded.