When subjects are instructed to group successively presented signals in that two responses must be simultaneously carried out, the total processing time is found to depend on the perceptual organisation of the stimulus display and on signal-response compatibility. Response grouping is very inefficient in the case of low SR compatibility, suggesting a mutual interference process between response choices. When subjects are asked to handle the signals successively, the processes were not affected by compatibility. The instruction was difficult to obey however and delivered results that did not fit the Welford-Davis model on the psychological refractory period. The results are consistent with the conception of the reaction process as a series of successive transformations of the signal.
Samenvatting