Reaction time and the psychological refractory period in children and adults

Abstract

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.

A comparison between the models of the psychological refractory period proposed by Welford and Surwillo and Titus

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A model of the psychological refractory period (PRP) proposed by Surwillo and Titus (1976) is compared critically with that proposed by Welford (1952) noting the following points:(1) Surwillo and Titus augment the single channel hypothesis of Welford's model with other assumptions that are unnecessary as Welford's model fits their data (and the great bulk of other studies) with great precision.(2) An anomaly overlooked in their application of the model to the data was found, namely, a counterintuitive decrease in reaction time to the 2nd stimulus below its asymptotic value. This has not been reported in any PRP data.

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“…A model of the psychological refractory period (PRP) proposed by Surwillo and Titus (1976) is compared critically with that proposed by Welford (1952) noting the following points:…”

“…The model of the psychological refractory period (PRP) proposed by Surwillo and Titus (1976) is overelaborate in that the original single channel theory as put forward by Welford (1952) provides a very good description of the data that Surwillo and Titus used to justify their model, without the elaboration of input to processing being gated by the brain's a-rhythm. Welford's simple model states that a response to the 2nd of 2 signals given in close succession will be delayed by the duration needed to process the 1st.…”