Oscillatory beta activity predicts successful feature binding in face processing

Reasoning enables animals to respond correctly in unexperienced situations. The purpose of this study was to examine the involvement of the dorsolateral prefrontal cortex (DLPFC) in inductive reasoning, which is regarded as the most intuitive and simple type of reasoning. We trained a monkey to perform a repeated group-reversal task, which requires inductive reasoning at the stimulus-reward reversal, using 8 discrete visual stimuli. During the performance of this task, we recorded single-unit activity from DLPFC neurons. Of neurons responding selectively to the visual cue according to the predicted liquid (either juice or saline), the majority reversed the stimulus selectivity when it was presumed that the monkey realized the stimulus-liquid reversal by inductive reasoning. We also found that some neurons show elevated tonic activity during the presumed inductive reasoning. These results suggest an important role of DLPFC neurons in inductive reasoning.