Classification on the basis of conditional cues

Abstract

Subjects were presented with signals from two sources, either simultaneously or successively. The signal from one source, the “cue” signal, provided information about the type of classification to be made; the signal from the other source provided the data for the classification. Reaction times were recorded from the moment of presentation of the second signal to the moment the subject pressed the appropriate response key. By varying the order of presentation and the time interval between cue and data signal, the time required for the subject to select the appropriate dimension of variation in the data signal was examined.

When the cue signal preceded the data signal, the results were consistent with consecutive sequential processing of the two signals. When the data signal preceded the cue signal a further source of delay was evident. It is suggested that this results from a type of intermittency in which processing of irrelevant aspects of the data signal holds up the analysis of the cue signal.