A dual-task analysis of resource allocation in dysthymia and anhedonia

Research has shown dysthymic individuals to be hyporesponsive at various stages of information processing, yet it is not clear whether dysthymics are deficient in the amount of available attentional resources for information processing or, instead, in the allocation of those resources. To distinguish between these possibilities, the authors compared dysthymics to anhedonic and normal control Ss during the performance of memory tasks, under conditions of varying task priority and difficulty. Although there were no performance differences, dysthymics and anhedonics exhibited a consistently smaller P300 component of the event-related potential. Furthermore, P300 results indicated that dysthymics and anhedonics responded differently from controls to variations in task demands. Thus, although evidence was obtained for group differences in both resource capacity and resource allocation strategy, the overall pattern of results is interpreted as favoring the latter.