Is There a Specific Executive Capacity for Dual Task Coordination? Evidence From Alzheimer's Disease

Robert H. Logie, Gianna Cocchini, Sergio Delia Sala, Alan D. Baddeley
2004 Neuropsychology  
Three experiments compared groups of Alzheimer's disease (AD) patients and healthy older and younger participants on visuospatial tracking and digit sequence recall, as single tasks and performed concurrently. In Experiment 1, tasks were performed concurrently with very low demand relative to span. Only the AD patients showed a dual task deficit. In Experiment 2, single task demand was manipulated on each task from below span to above span for each individual. All groups showed the same
more » ... ed the same performance reductions with increasing demand. In Experiment 3, demand on 1 task was constant, whereas demand on the concurrent task was varied. AD patients showed a clear dual task deficit but were no more sensitive than control groups to varying demand. Results suggest an identifiable cognitive resource for dual task coordination within a multiple component working memory system. Baddeley, Logie, Bressi, Della Sala, and Spinnler (1986) reported a specific impairment in the ability of patients with Alzheimer's disease (AD) to perform two tasks concurrently. This effect did not appear to be present in normal aging, and the impairment appeared to be quite independent of any impact of the disease on the performance of each task separately. Moreover, dual task performance declined as the disease progressed, and the effect did not appear to arise from overall effects of task demand
doi:10.1037/0894-4105.18.3.504 pmid:15291728 fatcat:y5eijdvzszefddf2umlslvq56q