Performance of rhesus monkeys on spatial delayed response (indirect method).

Abstract

This report describes a series of experiments designed to elucidate the role of stimulus and response factors in delayed-response (indirect method) performance of monkeys. It was shown that: (a) longer stimulus presentation durations (11 sec.) result in poorer performance than do shorter durations (1 sec.); (b) an equivalent relation exists for length of delay; (c) performance is better when all trials are conducted with light stimuli of a single color than it is when a different color is used on successive trials; (d) proficiency is lower if the response is executed when both correct and incorrect boxes are lighted than it is when none of the boxes is lighted; (e) there is a strong tendency for the centralmost of five stimuli to occasion the most difficulty; and (f) the intermingling of long-delay trials with short-delay trials causes a reduction in performance on the short-delay trials, (g) Screening the stimuli during the delay period seriously disrupted performance. (h) The irradiated monkeys performed as proficiently as did the normal monkeys. (PsycINFO Database Record (c) 2006 APA, all rights reserved)