Reaction time and the psychological refractory period in children and adults

The psychological refractory period-the prolonged reaction time (RT) to the second of 2 closely-spaced stimuli-was investigated in groups of 13 children and 13 adults. Subjects responded as fast as possible to the 2nd of 2 loud clicks that were presented after a soft click which served as a ready signal. The inter-stimulus interval (ISI), or time between loud clicks, was investigated as an independent variable. The results for ISI's of 50, 100, 250, and 500 msec confirmed the existence of an inverse relationship between RT and ISI. In accordance with the hypothesis investigated, RT was more prolonged in children than in adults as ISI decreased. Findings were consistent with the view that refractory period (RP) of an information-processing element in the central processor is longer in children than in adults. A single-channel model of information processing was proposed which could explain the inverse relationship between RT and ISI; could account for the slope differences between the RT vs ISI curves from children and adults; and could account, in part, for the overall longer RT's of children than of adults.