Mental fatigue impairs pre-attentive processing: a MMN study.

Individuals frequently experience mental fatigue during or after prolonged periods of cognitive activity. We investigated the effects of mental fatigue on the ability to detect minor changes in the pre-attentive stage of information processing by recoding MMN of ERP components. The equal probable paradigm was employed to elicit pure memory-comparison-based MMN component. Mental fatigue was induced by the continuous performance for 2h of mental arithmetic tasks. MMN amplitudes at fronto-central electrode sites were significantly decreased in subjects with mental fatigue than in subjects under control conditions, whereas temporal MMN was not affected by mental fatigue. These results suggest that mental fatigue impairs pre-attentive processing.