Central processes in gustatory adaptation

In two experiments the adapting stimuli at the periphery of the taste system were of a constant objective intensity but, using mixture suppression and spatial summation, their perceived intensity was varied. The results have shown that, in spite of the constancy in stimulus concentration, the adaptation degree changed with the perceived intensity of the stimulus. The adaptation to the compounds when in binary mixtures proved to be significantly less effective than the adaptation to the same equimolar compounds when unmixed. Similarly, the adaptation effects of solutions of a constant concentration, when applied to a small tongue area, were significantly smaller than when applied to a larger area. This adaptation dependence upon the taste sensation intensity suggests that in the gustatory adaptation, peripheral as well as central processes take part.