Circadian Phase and Time-of-Day Effects in Cognitive Testing: A Review of an Ignored Confound

Authors

  • Emil-Peter Kollar-Bel Centre for Sleep Research, Hont Institute of Cognitive Neuroscience, Krupina, Slovakia Author
  • Dominica Errasti Centre for Research Methods, Sierra de Gredos Institute of Cognitive Neuroscience, Arenas de San Pedro, Spain Author
  • Jean-Paul Colling Department of Cognitive Psychology, Wiltz Valley Institute of Cognitive Neuroscience, Wiltz, Luxembourg Author

DOI:

https://doi.org/10.5281/zenodo.22680869

Keywords:

Circadian Phase and Time-of-Day Effects in Cognitive Testing; Cognitive neuroscience; Neurofeedback; Evidence synthesis; Research methodology

Abstract

Circadian Phase and Time-of-Day Effects in Cognitive Testing has moved quickly from a niche scientific question to something a
wider community can now investigate with reasonably reliable tools, but the evidence behind it has not always kept pace. We pull
together the current evidence for circadian phase and time-of-day effects in cognitive testing, covering the methodological,
practical, regulatory and cost angles, with an eye on where practice has genuinely settled and where researchers and reviewers
are still largely working it out for themselves. Selective, context-specific pursuit looks better supported by the evidence gathered
here than either broad rollout or blanket avoidance.

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Published

2025-02-10