The effect of distraction on selective attention.

Abstract

The effects of a vigilance distractor were investigated with respect to recall of task-relevant and task-incidental information on a memory task. 40 children per grade in the first, third, fifth, and seventh grades were given the task; half were tested under distraction conditions. It was found that recall of task-relevant material increased regularly with age, while recall of taskirrelevant (incidental) material showed no significant change with age level. Distraction had a very significant effect on the task-relevance performance but did not affect incidental performance except at the oldest grade level. No interaction was found between type of recall measure and distraction. Correlations between central and incidental performance were significantly negative at the seventh-grade level only. These findings are consistent with the information-processing model presented, which accounts for the development of selective attention processes. That attention and memory abilities increase with age during childhood is well known, but the reason for the improvement is far from established. To offer an explanation, Maccoby and Hagen (1965) have formulated an information-processing model based on previous work of Broadbent (1958). Broadbent conceptualizes the nervous system as a single communication channel with a limited capacity. Within this limited capacity, selective filters operate to separate relevant from irrelevant information. These selective mechanisms encode information on the basis of some fairly gross This study is based on a thesis submitted by the author to Stanford University as partial fulfilment for the requirements for the Doctor of Philosophy degree. The author was a predoctoral fellow of the National Institute of Mental Health at the time. The author wishes to express thanks to Earl Whitaker, Assistant Superintendent of Schools, Redwood City, California, for his cooperation, and to Linda George and Richard Ashmore for their assistance in this study.