Taste-Discrimination in the Monkey

Abstract

Taste-discrimination in animals has been investigated traditionally by the use of some variant of the 'preference method' in which the discrimination is evidenced by the relative amount of a fluid that is consumed in a free-choice situation. The limitations of this procedure as a way of determining taste-sensitivity are, by now, well organized.1 It confounds the discriminative function of the taste-stimuli with a reinforcing function, since the reinforcement is obtained directly from the solutions to be discriminated. Consequently, it becomes uncertain whether a failure to discriminate relates to factors of taste-sensitivity or to the reinforcing role of the stimuli, or both. Moreover, under conditions which involve the consumption of appreciable amounts of hypertonic fluids, taste and preference become further confounded with post-ingestional osmotic factors as determinants of the discriminative behavior.2