This open access article may interest my sleep & fatigue colleagues. They looked at how post-sleep experiences influence a person’s subjective evaluation of their sleep evaluation from the previous night.
ABSTRACT
How we form judgements of sleep quality is poorly understood. Emerging literature suggests that people infer their sleep quality based on multiple sources of accessible information, raising the possibility that sleep quality judgement may evolve as new relevant information becomes available. This study investigated whether people’s rating of sleep quality of the night before changes throughout the following day, and what post-sleep factors are associated with the changes.
A prospective experience sampling study of 119 healthy young adults, who completed eight short online surveys interspaced 2 hr apart from 08:00 hours to 22:00 hours. Each survey asked the participants to report total sleep time and sleep quality of the night before, and to provide ratings of current mood, physical and social activity, and pain/discomfort. A memory test was added to the final survey of the day to measure the participants’ recall of their first survey responses to sleep quality, as well as total sleep time and mood.
The absolute majority (91.1%) of the participants had one or more change in their sleep quality rating across the eight surveys. A similar percentage of change was found for mood rating (100%) but not total sleep time report (20.5%). Memory test in the final survey revealed that the within-person variations in sleep quality rating were not simply memory errors. Instead, positive physical activity post-sleep predicted increases in sleep quality rating.
Therefore, judgement of sleep quality of the night before changes as the day unfolds, and post-sleep information can be used by people to infer their sleep quality.
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Some interesting observations from the full paper:
- People’s evaluations of their sleep quality changed over different times of the day when asked for their evaluation (91% revised their original sleep quality score)
- They note that “changes in participants’ SQ ratings were not simply the result of memory or reporting errors. Instead, physical activities that occurred after the sleep period had an influence on people’s SQ ratings during the day, even when the effects of age, gender, ethnicity, chronotype and the start hour of the day were controlled for” (p7)
- The “valence of physical activity made a difference in that only positive physical activity had a significant effect on the SQ change score” (p7). That is, only positive physical activities had a statistically significant effect on changes in sleep quality ratings post-sleep
- Thus, sleep quality “is an inferential process, subject to changes that occurred during the day after the sleep period” (p7)
- They also note that changes in sleep quality “are not a confound of circadian rhythm. They were not mere reporting instability or memory errors, because similar changes were not observed for TST reports and the participants were able to recall their first SQ rating of the day with greater accuracy” (p7)
Importantly, they clarify that the judgement of sleep quality isn’t necessarily unreliable just because it evolves over the day. Nor is it a reason to “justify the often-held assumption that ratings of SQ are somehow less scientific or informative than SQ scores calculated from multiple device-measured sleep parameters” (p8).
Instead, the findings indicate that sleep quality ratings reflect more than just the night-time sleep experience and also incorporate the evaluation of post-sleep experiences. Thus, “This renewed definition of SQ ratings helps explain why a combination of a large number of PSG-defined sleep measures explains only up to 17% of variance in SQ ratings” (p8).
They provide some insights on how these insights can be leveraged. One idea is to adopt more of a 24-h perspective on sleep quality, by “actively focusing on both improving sleep experience at night as well as enhancing activity engagement during the day” (p8).
The findings also have implications for the monitoring and assessment of sleep & fatigue indices, such as from occupational fatigue perspectives.
Study Link: https://doi.org/10.1111/jsr.13764
Link to the LinkedIn post: https://www.linkedin.com/posts/benhutchinson2_judgement-of-sleep-quality-of-the-previous-activity-7004988693316866048-KZLZ?utm_source=share&utm_medium=member_desktop
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