MULTIDIMENSIONAL AUDITORY STIMULUS-CONTROL IN A CHIMPANZEE (PAN-TROGLODYTES)

An adolescent female chimpanzee (Pan troglodytes) was trained to discriminate auditory compound stimuli differing in tonal frequency and/or tone on-off rate. Following acquisition training and overtraining, she was shifted to multidimensional stimulus control testing using redundant relevant auditory stimulus sets with discriminability of elements in each dimension varied systematically. Although the control by both dimensions changed significantly as a function of discriminability, the degree of dimensional control was stronger in the tone on-off rate than in the tonal frequency. These results clearly demonstrated "attentional" control of the chimpanzee's auditory discrimination behavior and the interaction between two dimensions of auditory stimuli. © 1990 Japan Monkey Center.