Healthy Sleepers Can Worsen Their Sleep by Wanting to Do so: The Effects of Intention on Objective and Subjective Sleep Parameters

Abstract

Purpose

Sleep is regulated by homeostatic and circadian factors. In addition, psychological factors have a strong modulatory impact on our sleep, but the exact underlying mechanisms are still largely unknown. Here, we examined the role of intentions on subjective and objective sleep parameters. Young healthy sleepers were instructed to voluntarily either worsen or improve their sleep. We predicted that participants would be capable of worsening, but not improving, their sleep compared to a regular sleep condition. In addition, we predicted that the instruction to alter sleep would lead to a higher discrepancy between subjective and objective sleep variables.

Participants and Methods

Twenty-two healthy students participated in one adaptation and three experimental nights. Polysomnography and subjective sleep parameters were measured during all four nights. Participants were instructed to sleep regularly (“neutral”), better (“good”) or worse (“bad”) than normal, in a counterbalanced order.

Results

The instruction to sleep “bad” increased objective sleep onset latency and the number of awakings during the night. The effects were stronger on subjective sleep variables, resulting in a higher sleep misperception in the “bad” condition as compared to the other two conditions. The instruction to sleep “good” did not improve sleep nor did it affect sleep misperception.

Conclusion

We conclude that intention is sufficient to impair (but not improve) subjective and objective sleep quality and to increase sleep misperception in healthy young sleepers. Our results have important implications for the understanding of the impact of psychological factors on our sleep.

Keywords:

• cognition
• sleep
• sleep quality
• intention
• sleep misperception

Acknowledgments

We thank Fiona Hart-Hoenig for leading the pilot study as well as Valentina Arnold, Sarah Locher, Rahel Schärli, and Anna Wick for helping with the data collection. A special thank goes to Louisa Clarke for her effort in proofreading. This study was supported by a grant from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement MemoSleep No. 677875).

Disclosure

Financial disclosure: AVA AG, Zurich supported the project with 900.00 CHF. Non-financial disclosure: The authors report no conflicts of interest for this work.