Differential delay-of-reward training and subsequent discrimination learning in children

Abstract

Four groups of 16 first-grade children were given 40 single-stimulus training trials and then 100 trials on a subsequent two-choice visual discrimination test which employed the previous stimuli as discriminanda. Two groups (D-0; D-10) experienced differential delays (either zero or 10 seconds) of reward following a response to each stimulus during the training trials. One Group (N-0) of nondifferentially trained Ss experienced a zero-second delay of reward, while Ss in the other nondifferential Group (N-10) experienced a 10-second delay, following a response to both stimuli. During the discrimination test the stimuli associated with zero delay in the differential conditions became positive for one group of subjects (D-0) and negative for the other (D-10). The positive discriminative stimuli in the nondifferential conditions were assigned randomly. Response speeds to the stimuli during training were inversely related to the delay of reward associated with that stimulus. Ss in Group D-10 began the discrimination with a significant number of incorrect responses. Their performance over trials, however, increased rapidly, and the overall level of discriminative performance for the differential Groups (D-0 and D-10) was superior to that following non-differential training (N-0 and N-10). Results were interpreted in terms of a mediating response model.