fMRI study of taste cortical areas in humans.

We used 3 Tesla functional magnetic resonance imaging (fMRI) with echo planar imaging to map taste projections in the human. Activations were found surrounding and buried in the sylvian fissure; the upper part of insula, the frontal operculum, and the foot of the pre- and postcentral gyri were usually activated. Moreover, we could describe, for the first time, a lateralized associative projection located in the lower part of the dominant hemisphere of the subject (n = 10). We also observed activations in the anterior cingulate gyrus, the centromedial thalamus, and other areas related to emotional or cognitive processes. Thirty subjects were submitted to a familiarization experiment sampling neophobic and nonneophobic stimuli. Measurements of isointense concentrations, magnitude estimates and hedonic values were assessed repetitively for 10 weeks. Five subjects performed 3 fMRI experiments, before, during and after familiarization. Psychophysical data showed a relationship between the evolution of the hedonic assessment and the intensity of the perception, and fMRI results showed a relationship between the evolution of the hedonic assessment and the evolution of the percent of activated pixels in taste cortical area.