Qualities and locations of stimuli and responses affecting discrimination learning of chinchillas (Chinchilla laniger) and pigeons (Columba livia).

Chinchillas and pigeons were used as subjects in separate experiments to study interactions among stimulus and response characteristics in discrimination learning. Both the stimuli and the responses could differ with respect to their "quality" and their "location." Bright versus dim lights and upper versus lower lights served as the stimulus qualities and stimulus locations for the chinchillas, respectively. Red versus green lights and upper versus lower lights served as the stimulus qualities and stimulus locations for the pigeons, respectively. Respond versus no-respond and respond-left versus respond-right served as the response qualities and response locations, for both species, respectively. In both experiments, response-quality performance was superior when the discriminative stimuli differed in quality than when they differed in location, whereas response-location performance was superior when the discriminative stimuli differed in location than when they differed in quality. These results were interpreted within the framework provided by a general law of learning, that is, the "quality-location hypothesis."