Effects of pre-sleep cognitive intrusions on subjective sleep and next-day cognitive performance in insomnia

Pre-sleep cognitive intrusions about next-day activities, or proprioceptive and environmental stimuli are thought to trigger insomnia in neurocognitive models. Recent research showed that intrusive cognitions at bedtime may interact with sleep in influencing next-day emotional functioning; their effects on cognitive functioning, however, is largely unknown. We tested the effects of pre-sleep cognitive intrusions on subjective sleep and next-day cognitive performance in 80 participants, either with chronic insomnia or good sleepers. Pre-sleep intrusions were inspected using a validated questionnaire and sleep was assessed with a sleep diary. Cognitive functioning the following morning was measured using task switching paradigm assessing executive functions. Structural equation modelling with manifest variables (i.e., path analysis) shows that pre-sleep cognitive intrusions predicted increased sleep onset latency and wake after sleep onset, and lowered sleep efficiency. Moreover, task switching accuracy was independently predicted by pre-sleep cognitive intrusions in the previous night in those with insomnia but not in controls, beyond the effects of trait anxiety, task switching components, and previous night's sleep. Findings confirm detrimental effects of pre-sleep intrusions on sleep continuity and suggest the presence of links between pre-sleep conscious activity and next-day executive performance in patients with insomnia, with the need to better elucidate potential mediators.