Temporal dynamics of subjective sleepiness: A convergence analysis of two scales

ABSTRACT

While sleepiness assessment metrics were initially developed in medical research, subjective sleepiness assessment is now widely used in both fundamental and applied studies. The Stanford Sleepiness Scale (SSS) and the Karolinska Sleepiness Scale (KSS) are often considered the gold standard in sleepiness research. However, their convergence and specific features have not been sufficiently investigated. The present study aims to analyse the dynamics and convergence of subjective sleepiness as measured by the KSS and SSS. A total of 208 adults participated in the experiment. Our findings suggest that sleepiness generally increased from the evening till night and was highest early in the morning. The SSS score appeared to be more sensitive to certain factors. The SSS and KSS scores strongly correlated with each other and converged on sleepiness assessment. However, the KSS showed a more even distribution of scores than the SSS. Currently, we are continuously expanding the SSDD.

KEYWORDS:

• Sleepiness
• temporal dynamics
• convergence
• SSS
• KSS

Acknowledgments

This work was supported by the Russian Science Foundation under Grant No. 22-28-20509.

The authors would like to thank all the interns of the Cyberpsychology Lab who communicated with the participants and took part in data collection.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work was supported by the Russian Science Foundation [22-28-20509].