Transcranial direct current stimulation targeting the bilateral IFG alters cognitive processes during creative ideation

This study investigated whether transcranial direct current stimulation (tDCS) targeting the inferior frontal gyrus (IFG) can alter the thinking process and neural basis of creativity. Participants' performance on the compound remote associates (CRA) task was analyzed considering the semantic features of each trial after receiving different tDCS protocols (left cathodal and right anodal, L + R-; right cathodal and left anodal, L-R+; and Sham). Moreover, we constructed and compared 80 prediction models of CRA performance for each group based on task-related functional connectivity. Results showed that L + R- stimulation improved performance in semantically bundled CRA trials, while L-R+ stimulation enhanced performance in trials with greater semantic distance. Furthermore, alpha-band task connectivity models for the L + R- group showed inferior performance and greater left frontal lateralization than other two groups. These findings suggest that tDCS targeting the bilateral IFG alters cognitive processes during creative ideation rather than enhancing or impairing an established thinking process.