Attentional bias towards sleep-related stimuli in insomnia disorder: a behavioural and ERP study.

Many studies have used behavioural experiments to show an attentional bias towards sleep-related stimuli in people with insomnia disorder. A measurement of event-related potential is needed to investigate the cognitive processing mechanism of the attentional process. The present study used the emotional Stroop paradigm and event-related potentials to measure attentional bias towards sleep-negative, sleep-positive and sleep-unrelated neutral words. The study comprised 16 participants with insomnia disorder and 15 participants who were good sleepers. Behavioural data indicated that there was a significant interference effect of sleep-positive words between the insomnia group and the good sleepers, and a marginally significant interference effect from sleep-negative words between groups. In the insomnia group, event-related potential data showed that sleep-negative words elicited higher amplitudes of P1 and N1 components than did sleep-positive and sleep-unrelated words. Our results provide evidence for the early cognitive processing of sleep-negative stimuli, which suggests that the psychological treatment of insomnia could benefit from addressing early hypervigilance towards these stimuli.