Does sleep affect socio-emotional functioning?

In the first chapter I compare and contrast the extant literature on sleep loss and insomnia, including theories as to how insomnia develops and the role of the circadian and homeostatic systems. In Chapter 2 I summarize the extant literature on sleep, emotion perception, and social task performance, and review the relevant emotion literature. I then critically appraise this literature and suggest future directions for this field. In Chapter 3 I pilot an emotion recognition task among students, including measures of sleep and empathy. Results suggest that the previous nights’ sleep, as well as depression scores, are significant predictors of happiness recognition. In Chapter 4 I assess emotion recognition in insomnia using dynamic stimuli, and results suggest that insomnia disorder impairs the categorization accuracy of high intensity expressions of sadness and low intensity expressions of surprise. Sleep diary parameters were also found to be significant predictors of happiness recognition on both accuracy and reaction time measures. I then assess how normal sleepers perform with these stimuli in Chapter 5, testing subjects at different times since waking. Chapter 5 Experiment One suggests that the early group are more sensitive towards several temporal parameters, with no effects on emotion recognition. Chapter 5 Experiment Two suggests that normal sleepers tested early are less sensitive towards mid-intensity expressions of anger and sadness, with effects on intensity recognition. These results are interpreted in the context of differences with the two late-tested groups. Chapter 6 extends these results to static stimuli, with results suggesting that the early group tend to make more errors when categorizing happy faces. Chapter 7 returns to the daytime impairments in insomnia disorder, suggesting that theory of mind task performance is altered when reaction times are measured. As a result of issues raised in this thesis Chapter 8 systematically reviews the literature on how normal sleepers are screened for participation in research studies, suggesting future criteria. Chapter 9 summarizes these results in the context of hyperarousal and the etiology of insomnia disorder