Affect Across the Wake-Sleep Cycle

Abstract

Affective scientists traditionally have focused on periods of active wakefulness when people are responding to external stimuli or engaging in specific tasks. However, we live much of our lives immersed in experiences not related to the current environment or tasks at hand-mind-wandering (or daydreaming) during wakefulness and dreaming during sleep. Despite being disconnected from the immediate environment, our brains still generate affect during such periods. Yet, research on stimulus-independent affect has remained largely separate from affective science. Here, we suggest that one key future direction for affective science will be to expand our field of view by integrating the wealth of findings from research on mind-wandering, sleep, and dreaming to provide a more comprehensive account of affect across the wake-sleep cycle. In developing our argument, we address two key issues: affect variation across the wake-sleep cycle, and the benefits of expanding the study of affect across the full wake-sleep cycle. In considering these issues, we highlight the methodological and clinical implications for affective science.

Keywords: Affect coherence; Affect dynamics; Affect regulation; Dreaming; Mind-wandering; Sleep.

Fig. 1

Affect Varies Across the Wake-Sleep Cycle. Note. Affect varies across the wake-sleep cycle—from active wakefulness (when we are typically engaged in stimulus-dependent and/or task-related thoughts and experiences) to mind-wandering (characterized by stimulus-independent and/or task-unrelated thoughts and experiences) to dreaming during sleep (during which we are largely disconnected from the current environment). Existing studies suggest that the positivity bias—relative difference in positive vs negative affect—decreases across the wake-sleep cycle. Affect also differs depending on the method used to measure affect, that is, whether participants themselves rate the affect they experience using self-rating scales (referred to as self-ratings) or whether the affective content of narrative reports has been analyzed (referred to as affective content). Figures illustrate the findings from the experience sampling studies of (a) Gross et al. (2021) and (b) Sikka et al. (2021). a In Gross et al. (2021), 131 participants were probed three times during the day and two times during the night across 7 days about the affective nature of their experiences at that particular moment. b “The dynamics of affect across the wake-sleep cycle: From waking mind-wandering to night-time dreaming” by Sikka, P., Valli, K., Revonsuo, A., & Tuominen, J. (2021). Consciousness and Cognition, 94, 103189. 10.1016/j.concog.2021.103189. CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)