Purpose: To explore whether sleep electroencephalogram (EEG) microarousals of different standard durations predict daytime mood and attention performance in healthy individuals after mild sleep restriction.
Participants and Methods: Sixteen (nine female) healthy college students were recruited to examine the correlations between nocturnal EEG microarousals of different standard durations (≥ 3 s, ≥ 5 s, ≥ 7 s, ≥ 9 s) under mild sleep restriction (1.5 h) and the following morning’s subjective alertness, mood, sustained attention, and selective attention task performance.
Results: Results revealed that mild sleep restriction significantly reduced subjective alertness and positive mood, while having no significant effect on negative mood, sustained attention and selective attention performance. The number of microarousals (≥ 5 s) was negatively associated with positive mood at 6:30. The number of microarousals was significantly and positively correlated with the response time difference value of disengagement component of the selective attention task at around 7:30 (≥ 5 s and ≥ 7 s) and 9:00 (≥ 5 s). The number of microarousals (≥ 7 s) was significantly and positively correlated with the inaccuracy difference value of orientation component of the selective attention task at around 9:00.
Conclusion: The number of EEG microarousals during sleep in healthy adults with mild sleep restriction was significantly and negatively related to their daytime positive affect while positively associated with the deterioration of disengagement and orientation of selective attention performance, but this link is dependent on the standard duration of microarousals, test time and the type of task.

Keywords: microarousal, alertness, sustained attention, selective attention, sleep restriction