Attention allocation deficits in aphasia: An explanation of performance variability

This experiment assessed attention allocation patterns of persons with and without aphasia using a paradigm of target-detection single and dual attention tasks. Nineteen adult participants performed one non-linguistic single attention task (gender identification), one linguistic single attention task (word-picture match), and one dual attention task combining the two single tasks (word-picture match and/or gender identification). Eleven participants were adults with aphasia; six reliably performed all three attention tasks, two were reliable on both single attention tasks but not on the dual task, and three were reliable on only one single attention task. Eight participants were adults without aphasia who were matched on age and gender to the eight participants with aphasia who reliably performed at least 2 of the attention tasks. A repeated measures ANOVA on performance accuracy revealed no significant difference between the aphasia group and the control group. A repeated measures ANOVA on reaction time revealed significant main effects for group and task as well as a significant interaction. Post-hoc repeated t-tests revealed significant differences between the aphasia and control groups on the two linguistic tasks but not on the non-linguistic task. Inspection of standard deviation values revealed a higher level of variability in reaction time performance for individuals with aphasia than for individuals without aphasia. Similarly, greater variability was evident for the aphasia group as a whole than for the control group as a whole. Greater variability and slowed reaction time performances by participants with aphasia indicate an inefficiency in attention allocation, especially in linguistic tasks. These results support McNeil, Odell and Tseng\u27s (1991) attention framework for explaining the variability in language and communication performance of people with aphasia as an inefficiency in the allocation of attention resources