Time of day and chronotype in the assessment of cognitive functions.

The results of the research show that time-of-day effects on basic and more complex cognitive functions depend on an individual's chronotype with a dominant effect of synchrony between chronotype and time of cognitive testing, with large differences in circadian cycles between younger and older age groups. It is suggested that chronotype assessment and time of day control should be included as important variables in the diagnosis of cognitive function in both healthy and clinical populations. There is also an emerging need for further investigations to better understand how chronotype and circadian rhythms modulate human brain physiology and cognition.