The Cocktail Party Effect in Post-Stroke Fatigue: an EEG study

Abstract

AbstractObjectiveAn inability to selectively attend away from task irrelevant stimuli is thought to drive post-stroke fatigue. In this study we investigated if neural processing of task relevant stimuli, in the presence of noise (task-irrelevant stimuli), is compromised in post-stroke fatigue.MethodsAn auditory oddball task consisting of target, standard and novel tones was carried out with and without background noise while recording neural responses using electroencephalography. Participants responded to target tones with a button press. After each block, participants rated how effortful the block felt. Fatigue was measured using the fatigue severity scale. The effect of fatigue and noise on behaviour (response time, accuracy, and effort rating) and neural responses (amplitude and latency) was examined using mixed model ANOVAS.ResultsThose with fatigue had slower responses both in ‘noise’ and ‘no noise’ conditions. The response amplitude to the novel tones in the ‘noise’ condition was smaller, than ‘no noise’ condition, which was modulated by fatigue. The latency of response was longer, in the ‘noise’ when compared to ‘no noise’ condition which was not modulated by fatigue. likewise, perceived effort was also greater in the ‘noise’ condition, but not modulated by fatigue.InterpretationProcessing of novel stimuli in the presence of background noise is significantly altered in post-stroke fatigue, indicating a problem with attentional switching processes, one that selectively contributes to the feeling of fatigue without affecting performance.