Electrical Stimulation Over Left Inferior Frontal Gyrus Disrupts Hand Gesture’s Role in Foreign Vocabulary Learning

Abstract

Hand gestures are a potent aid in foreign language learning. The present experiment sought to enhance their utility using transcranial direct current stimulation (tDCS). Employing tDCS, we investigated whether stimulation over the left inferior frontal gyrus (IFG)—an area implicated in multimodal integration—increases gesture’s beneficial role in foreign vocabulary learning. Replicating previous research, we found that when participants learned words accompanied by iconic gestures, they demonstrated better retention of those words compared to learning with speech alone. However, when tDCS was applied to the region above the left IFG, the beneficial effects of gesture were absent. Despite the recent enthusiasm over neuromodulation techniques, the present results provide one case in which neural stimulation may actually disrupt, rather than help, learning.