Emotion regulation strategies in subclinical insomnia: electrophysiological insights into neural processing...

This study aimed to investigate the neurobehavioral differences in emotion regulation strategies between individuals with insomnia disorder (ID) and normal controls (NC) using electrophysiological (EEG) assessment, addressing the research gap in understanding how insomnia affects emotion regulation strategies.

Twenty-five individuals with subclinical insomnia disorder symptoms (ID group) and twenty-two normal controls (NC group) were recruited from local universities. Participants completed emotion regulation tasks using Neutral-View (NV) and Controlled Reappraisal (CR) strategies while undergoing EEG recording. Behavioral responses, EEG measures including frontal alpha asymmetry, Event-Related Potentials (ERPs), and frequency-domain analyses were collected and compared between groups.

Behaviorally, the ID group showed longer response times when using NV versus CR strategy, while NC group showed no such difference. The ID group also reported lower arousal levels to emotional stimuli. Electrophysiologically, the ID group exhibited decreased frontal left-right alpha asymmetry and altered ERP components, including smaller N2, P2, and Late Positive Potential (LPP) amplitudes, but larger P3 amplitudes compared to NC group. Time-Frequency analysis revealed that ID group demonstrated greater theta power overall and enhanced posterior alpha power specifically when using CR strategy for negative images. In contrast, NC group showed distinct anterior-posterior beta power differences during NV strategy that were absent in ID group. Importantly, alpha oscillations correlated significantly with behavioral performance in NC group but not in ID group, suggesting altered brain-behavior coupling in insomnia.

These findings suggest that individuals with insomnia demonstrate distinct behavioral responses to top-down emotion regulation. The observed alterations in neural response patterns may serve as contributors to the persistence of both insomnia and associated emotional dysregulation.