Spatio-temporal analysis of cortical activity evoked by gustatory stimulation in humans

Gustatory activated regions in the cerebral cortex have not been identified precisely in humans. In this study we recorded the magnetic fields from th e brain in response to two tastants, 1 M NaCl and 3 mM saccharin. We estima ted the location of areas activated sequentially after the onset of stimula tion with magnetic source imaging. We investigated the primary gustatory a rea (area G) precisely, and found it at the transition between the parietal operculum and the insular cortex. The central sulcus was activated less fr equently than a rea G but with almost the same latency in cases of NaCl sti mulation. Following a rea G, we found activation in several cortical region s, e.g. both the frontal operculum and the anterior part of the insula, the hippocampus, the parahippocampal gyrus and the superior temporal sulcus.