The study is designed to investigate the impact of three nights of sleep restricted to 4 hours per night, on the processing and regulation of emotional information compared to Insomnia Disorder and control. The investigators will address and attempt to answer two questions.
(i) How do three nights of reduced sleep or a diagnosis of Insomnia Disorder affect the processing and regulation of emotional information compared to typical, undisturbed sleep? (ii) What overlapping and distinct neural mechanisms are engaged and associated with behavioral effects when attempting to process and regulate emotions in a sleep restricted state or with a clinical diagnosis of Insomnia Disorder? This study will investigate sleep's role in emotion processing and regulation. The findings will help further understanding of the role of sleep in healthy emotional functioning.