Sleep Deprivation Affects Emotion Regulation, But Not Processing

Study data published in PLoS One describe the potential effects of sleep deprivation on emotion regulation. In a cohort of healthy adults exposed to sleep deprivation, processing and memory remained uninhibited, but the regulation of negative emotion experienced decrements.

This study was conducted in a controlled laboratory setting at the Sleep and Performance Research Center at Washington State University. Healthy adults spent 4 days in the laboratory, during which they underwent a battery of tests assessing memory, cognition, and emotion regulation.

After 1 night of monitored sleep and laboratory acclimation, patients were randomized in a 2:1 ratio to either a total sleep deprivation condition or a rested control condition. During night 2, patients in the sleep deprivation condition were kept awake, while patients in the control condition were given a 10 hour sleep window. At the end of day 3, all patients were given a 10 hour sleep opportunity. Subjects left the laboratory on the afternoon of day 4.

During each day, patients regularly completed the Positive and Negative Affect Schedule (PANAS) and the Affective Psychomotor Vigilance Test, which measured mood and sustained attention capacity, respectively. An emotion regulation task was also administered, during which patients were instructed to either attend or decrease their emotional response to a prompt image.

Finally, patients completed affective categorization tasks, in which they were asked to describe the emotions present in a prompt image. Linear mixed-effects models were used to capture the effect of study condition on emotion regulation and affective processing.

A total of 60 adults were randomized: 40 to the sleep deprivation condition and 20 to the rested condition. Patient ages ranged from 22 to 37 years and 50% were women.

A significant effect of the study condition was observed with a positive effect on the PANAS, with the sleep deprived group experiencing significant declines in positive affect scores over study duration (P <.001). The same effect was not observed for patients in the well-rested condition. Scores on the affective categorization task were not significantly different between study groups (P =.789), suggesting that sleep deprivation did not affect the patients’ ability to characterize emotional images.

Additionally, sleep deprivation did not appear to affect performance on attention or working memory tasks. However, a significant main effect of the study condition was observed on emotion regulation task outcomes. Specifically, patients in the deprivation condition rated images as more negative during the second (postdeprivation) regulation task compared with the first task (P <.001). This finding suggests that sleep deprivation may impair the ability to regulate responses to negative prompts. Patients in the well-rested condition did not display this effect.

These data provide insight into the impact of sleep deprivation on certain emotional processes. While patients in both conditions remained able to process and categorize emotional prompts, emotion regulation was impaired by sleep deprivation. Further research is necessary to better explore the relationship between affective processing and emotion regulation.

“[I]n contrast to past work…we found that sleep deprived individuals do not differ significantly from their rested counterparts in attending to, identifying, updating, and maintaining affective information, indicating that bottom-up flow of affective information is not affected by [total sleep deprivation],” the investigators wrote.

“In conclusion, our evidence indicates that sleep-loss related changes to emotional processing are not likely due to changes in bottom-up components of affective processing.”