Impaired executive functions in subjects with frequent nightmares as reflected by performance in different neuropsychological tasks.
Brain and Cognition April 1, 2012 Péter Simor, Péter Pajkossy, Klára Horváth et al.
People who frequently experience nightmares show measurable impairments in certain thinking tasks during the day, particularly those requiring suppression of irrelevant information. In two studies, nightmare subjects were slower on emotional Go/NoGo and Stroop tasks, made more perseveration errors, and generated fewer words on a verbal fluency task compared to matched controls. These deficits appeared as an overall slowing regardless of whether the stimuli were emotionally positive, negative, or neutral. Poor sleep quality and waking anxiety accounted for some but not all of the differences. The findings suggest that frequent nightmares are linked to executive function difficulties involving the control of task-irrelevant semantic information.