Dual-Task Processing: Effects of Task Difficulty and Stimulus Similarity on Dual-Task Performance

Abstract

Previous research on factors that influence divided attention have focused on resource allocation, age of participants, task difficulty and familiarity, practice effects as well as brain areas that control dual task performance. The present study examined the effects of task difficulty and stimulus similarity on dual-task performance. One hundred and twenty participants, divided into four equal groups were asked to read a typewritten passage and at the same time to listen to an auditory message. The tasks for each group differed in terms of similarity and difficulty. The results showed no significant main effect of task difficulty ( F(1.116) = 1.36, p>0.05) and a significant main effect of stimulus similarity ( F(1.116) = 51.51, p<0.05). Performance in the conditions was dependent on stimulus similarity and information type. In terms of significant interaction effects, interference effects were observed more in the easy—dissimilar and difficult—dissimilar conditions than in the easy—similar and difficult—similar conditions. The results are discussed in the context of language processing and dual—task processing. Suggestions for future research are made.