Effect of mental fatigue on nonattention: a visual mismatch negativity study

Individuals experience mental fatigue during or after prolonged periods of cognitive activity. The aim of the present study was to investigate the effect of mental fatigue on detection of changes at the preattentive stage in the visual system by recording visual mismatch negativity of event-related potential components. Twenty-four students who volunteered for the study were divided randomly into either a mental fatigue group or a control group. Participants in the mental fatigue group were asked to perform an AX continued practice test for 2.5 h while the control group rested in the lab for 2.5 h. Then, subjective fatigue and mood state were measured by the Subjective Fatigue Symptom Questionnaire and the Profile of Mood States, respectively. Preattentive processing was evaluated as well by assessing the duration of the passive oddball task both before and after manipulation. In participants who performed the AX continued practice test, we observed a significant increase in feelings of fatigue and tiredness, and negative emotion. In these same participants, we observed a significant decrease in attention and positive emotion. This indicates that continuous cognitive operation induces mental fatigue. In addition, we found that the visual mismatch negativity amplitude was significantly reduced in participants with mental fatigue, implying that visual deviant/change detection is affected by mental fatigue. These results suggest that preattentive change detection and automatic processing decline as a result of mental fatigue.