Preference aversion in mice to bitter substance.

Preference-aversion functions demonstrable for sweet and salty stimuli have been found for a "bitter" substance, sucrose octaacetate, at individually specific concentrations for mice. The data support Schneirla's views correlating stimulus magnitudes and approach-withdrawal. The positive reinforcing value of this bitter substance as a weak stimulus is diminished with continuous exposure and no secondary reinforcement. Avoidance is related to intensity of stimulation rather than modality or postingestion effects.