Relationship between self-reported symptoms of fatigue and cognitive performance: switch cost as a sensitive indicator of fatigue

Abstract

In two correlational studies, we investigated the relationship between symptoms of mental fatigue connected with the ordinary daily activity of undergraduate students and the performance level in tasks engaging executive and attentional processes. We found that mild or moderate levels of fatigue are associated with only a few impairments in cognitive functioning, which suggests that the consequences of such a level of fatigue can be easily compensated by protection strategies adopted by participants. A notable exception was a significant positive correlation between the level of fatigue and higher accuracy switch cost in the Plus-minus task. Our participants also reported an increase in fatigue symptoms after performing several cognitive tasks and this change was larger for those who were more engaged in a sustained attention task. In a follow-up experiment, we investigated the effects of fatigue induced by the time on sustained attention task on switching task performance and reported symptoms of cognitive and executive fatigue. We confirmed that the level of accuracy switch cost is significantly higher in the participants who performed the sustained attention task than in the participants from the control group. We pointed out some possible practical implications of studies on the relationship between fatigue and cognition for such activities as driving a car.