Some Observed Differences in Degree of Concentration and Their Effects on Shadowing

Abstract

Three shadowing experiments investigated the hypothesis that difficulties in concentration are caused by internal factors as well as by the novelty, intensity or salience of background events. On the last trial of each experiment, a background message, which subjects had been instructed to ignore, changed unexpectedly. Most subjects noticed these changes and were disrupted by them (Experiments 1, 2 and 3). A smaller number of “concentrators” reported that they were unaware the changes had taken place. These concentrators were less disrupted by the background message than the non-concentrators both on the last trial and on earlier dichotic trials (Experiments 1 and 3). However, even concentrators were momentarily disrupted by the background changes (Experiment 3). Increased attended task difficulty increases the likelihood that subjects will fail to notice the changes (Experiment 2). The results support the view that good concentration consists in the ability to keep distracting events from consciousness.