Memory in Monkeys for Compound Stimuli

Abstract

The purpose of this paper is to describe the training of monkeys in a memory-task recently proposed by Konorski.1 This new method requires that the animal discriminate between two compound stimuli, each of which is made up of two signals within the same modality and separated by a short interval. As used by Konorski, a compound stimulus, consisting of two tones identical in pitch, is positive and is reinforced by food if it elicits the appropriate response from the animal (placing a forelimb on the food-tray).2 On the other hand, when the second signal is of a different pitch from that of the Erst, the stimulus is negative. It is not reinforced and the animal has to learn to leave the food-dispensing apparatus alone. In other words, the compounds Sx-Sx and Sy-SyX etc., are positive, while Sx-Sy and Sy-Sx are negative as long as 'x' differs from gy,