Dream affect : Conceptual and Methodological Issues in the Study of Emotions and Moods Experienced in Dreams

Abstract: We experience affect—emotions and mood—not only when we are awake but alsoduring dreaming. Despite considerable research, existing theories and empiricalfindings disagree about the frequency, nature, and correlates of dream affect. In thisthesis, I discuss the conceptual and methodological issues that underlie thesediscrepancies. I present five empirical studies, the overall aim of which was toinvestigate the phenomenology and correlates of dream affect and how resultsregarding these are influenced by study methodology. Studies I–III focusedspecifically on methodological issues, by comparing self- and external ratings ofdream affect (Studies I–II) or the affective content of home and laboratory dreamreports (Study III). Studies IV and V investigated the waking well-being and neuralcorrelates of dream affect, respectively. These studies show that results andconclusions regarding dream affect are very different, even contradictory, dependingon whether dream reports have been collected using sleep laboratory awakenings orhome dream diaries (Study III) or whether dream affect has been measured usingself- or external ratings (Studies I–II). Self- and external ratings of dream affect arealso differently correlated with waking well-being (Study IV). Together, theseresults caution against making broad generalizations about affective dreamexperiences from findings obtained with one type of methodology only. The studiesalso demonstrate that dream affect is related to aspects of waking well-being and illbeing(Study IV) and that certain affective states experienced in dreams, specificallyanger, rely on similar neural processes as in wakefulness (Study V). These findingssuggest that the phenomenology and neural correlates of affective experiences are,at least to some extent, continuous across sleep and wakefulness. Overall, this thesisshows how the conceptual and methodological issues in the study of dream affectmay limit the validity, generalizability, and replicability of findings and,consequently, pose challenges to theory building and theory testing. It contributes todream research by highlighting the need, and suggesting ways, to enhance theconceptual clarity and methodological rigour of research on dream affect. Due to theinterdisciplinary nature of the thesis, the theoretical discussion and novel empiricalfindings also have implications for emotion research, sleep research, well-beingresearch, consciousness research, and affective neuroscience.