Summary
Brain potentials from normals and patients with Chronic Fatigue Syndrome (CFS) were recorded in four different experimental tasks: (1) Auditory target detection, (2) Short-term memory scanning, (3) Fore-warned reaction time (contingent negative variation), and (4) Self-paced movement. In the auditory target detection task, a slow negative potential shift (maximum at Cz), appears prior to stimulus onset in normals, but is markedly reduced in amplitude in patients with CFS. However, all other sensory and cognitive brain potentials do not differ between normals and CFS. Reaction times are slower in CFS compared to normals. In the memory task, a slow negative shift associated with memory scanning is reduced in patients with CFS. For the fore-warned reaction time and self-paced movement tasks, no differences were found between the patients and normals. The finding of premovement related potential abnormalities in CFS supports the concept that central motor preparation and execution are impaired in CFS. In certain tasks, measures of neural processes related to sensory processing and attention are normal for these patients. Results from the memory task suggest that neural processes related to short-term memory are also altered in CFS.