Abstract: | This paper reviews the implications of a number of experimental results for a test between two different types of models of perceptual processing: models that assume a limitation of perceptual capacity vs models that postulate independent, parallel perceptual channels. The results of recent “detection” experiments (e.g., Estes & Taylor, 1966) have been consistent with the limited-capacity model developed by Rumelhart (1970). The same results, however, are predicted by the “ICC” independent-parallel-channels model, an extension of work by Eriksen and Spencer (1969) developed in the present paper. This model emphasizes the interaction of two factors: decisional properties of the detection task, plus perceptual confusion phenomena known to occur under tachistoscopic conditions.Two experiments relevant to a test between the ICC and Rumelhart conceptions are reported. Experiment I involved a “time-sharing” paradigm that varied the demands of two detection tasks performed within a single trial. Experiment II involved the elimination of certain perceptual confusion phenomena. The results of Expts I and II appeared consistent with the ICC model but inconsistent with the Rumelhart model. After consideration of alternative limited-capacity models, it was concluded that: (1) a decision-confusion interaction is a necessary component of information-processing models, and that (2) the ICC independent-parallel-channels model is sufficient to account for the broad spectrum of experimental results reviewed. |