High‐Definition Transcranial Direct Current Stimulation Over the Left Frontopolar Cortex Promotes Analogical Reasoning

ABSTRACT The objective of this study was to measure the contribution of the left frontopolar cortex (FPC) to analogical reasoning. Our measure of analogical reasoning derives from performance on the radiation problem, a creative problem‐solving task first used in Gestalt psychology (Duncker, 1945). Success on this task is as low as 10 % without the presentation of explicit cues that guide inference toward the solution (Gick & Holyoak, 1980). We assessed whether high‐definition transcranial direct current stimulation of the left FPC would promote the analogical transfer of the radiation problem. We found that anodal stimulation primed analogical transfer and led to improved task performance compared to the cathode and sham control groups. Results from this study offer evidence favoring the hypothesis that stimulating the left FPC facilitates analogical problem‐solving.