FUNCTIONAL MAGNETIC-RESONANCE-IMAGING OF CATEGORY-SPECIFIC CORTICAL ACTIVATION, EVIDENCE FOR SEMANTIC MAPS

Functional magnetic resonance imaging (fMRI) was used to examine the p attern of cortical activity during a picture naming task. Subjects (n = 12) had to covertly name either animals or furniture items. Function al scanning was performed using a conventional 1.5-Tesla whole-body MR I system. Images obtained during naming the two categories were compar ed using a non-parametric test. The study revealed evidence for domain -specific lexical regions in left middle, right middle and inferior fr ontal areas, as well as in superior and middle temporal areas. The res ults corroborate neuropsychological data and demonstrate directly and non-invasively in human volunteers that semantic representations in fr ontal and temporal areas are, to some degree, localized and possibly i mplemented as multiple maps. A completely distributed storage of seman tic information is rendered unlikely. (C) 1998 Elsevier Science B.V.