Abstract
The patterning or microstructure of a situation where subjects were presented with two sets of information from two independent ‘high decision’ information processing tasks, was investigated. Thirty-two subjects worked at the five-choice serial-response task (designated by instructions to be the main task), whilst being presented with a transformation task which required that seven had to be added to a presented auditory digit (designated by instructions to be the secondary task). Results suggested that subjects were not able to process two streams of information in parallel, and that the way in which the attention process was ordered was partly a function of task instructions and partly a function of the random occurrence of each digit in relation to the on-going serial task. Results also gave support to the view that the locus of disruption was the production of the response to the secondary task. Explanations of this effect are considered.