Evidence for peripheral and central processes in taste adaptation.

Abstract

Adaptation is one of the fundamental phenomena of taste perception. Adaptation is usually measured, as it was here, as the perceived intensity of a test stimulus following prolonged stimulation by an adapting stimulus. In this experiment, both the adapting and test stimuli were delivered via two pieces of filter paper—one soaked in sucrose, the other in water—placed on opposite sides of the tongue. Adaptation was greatest when the spatial relations of sucrose and water were the same for both the adapting and test stimuli, but was significant in comparison with a no-adaptation control when the spatial relations of the adapting and test stimuli were different. The result is discussed in terms of peripheral and central processes in taste adaptation: Peripheral processes were assumed to be engaged only when sucrose had the same spatial location for the adapting and test stimuli, whereas central processes were assumed to be responsible for the adaptation observed when sucrose had a different spatial location for the adapting and test stimuli. The implications of a multiprocess view of adaptation for psychophysical models of taste adaptation, the use of adaptation as a research tool, and future research on adaptation are discussed.