Ishibashi, R. 1, 2 , Lambon Ralph, M. 2 , Saito, S. 1 & Pobric, G. 2
1 Department of Cognitive Psychology in Education, Kyoto University, Japan
2 Neuroscience and Aphasia Research Unit, University of Manchester, UK
A remarkable cognitive ability in humans is the competency to use a wide variety of different tools. Two cortical regions, the anterior temporal lobes (ATL) and left inferior parietal lobule (IPL), have been proposed to make differential contributions to two kinds of knowledge about tools: function vs. manipulation. We used repetitive transcranial magnetic stimulation (rTMS) and two semantic decision tasks to assess the role of these regions in healthy participants. Participants made semantic decisions about the function (what for) or manipulation (how) of tools used in daily life. The stimulation of ATL resulted in longer responses for the “function” judgments, whilst stimulation of IPL yielded longer responses for the “manipulation” judgments. In line with the neuropsychological literature, these results indicate ATL and IPL disproportionately contribute different aspects of the representation of tools, supporting the “hub-and-spoke” theory of semantic memory.