Working memory deficits associated with chronic fatigue syndrome

Cognitive impairments are among the most frequently reported and least inve stigated components of the chronic fatigue syndrome (CFS). As part of a mul tifaceted study of the CFS, the present study investigated the cognitive fu nctioning of chronic fatigue patients. The performance of 20 CFS patients w as compared to that of controls (N = 20) on 4 tests of working memory (WM). Digit Span Forward was used to assess the storage capacity of WM. Multiple aspects of central executive functioning were assessed using several stand ard measures: Digit Span Backward, and Trails A and Trails B. More recently developed measures of WM were used to assess control of processing under t emporal demands (working memory task) and resistance to interference (a sus tained attention task). Deficits were restricted to more demanding tasks, r equiring resistance to interference and efficient switching between process ing routines. The overall results clearly implicate deficits in the control aspects of central executive function in CFS.