Chronotype Alignment and Time Perception

Official title

Circadian Match and Mismatch Effects on Temporal Cognition in Morning- and Evening-Type Adults

Overview

People differ in chronotype - whether they function best in the morning ("larks") or the evening ("owls"). This study asks whether the match or mismatch between a person's chronotype and the time of day at which they are tested changes how they perceive time. Healthy morning-type and evening-type adults at three sites (Aarhus, Denmark; Changzhou, China; and Hong Kong) complete the same battery of perception and cognition tasks twice - once in the early morning (about 08:00) and once late in the evening (about 22:00), in counterbalanced order. The primary outcome is the accuracy (signed bias) of time-perception judgements; the key comparison is the interaction between chronotype and time of day (the "synchrony effect"). Secondary measures include timing precision, the subjective passage of time, sleepiness, mood, colour perception (with and without blue-blocking glasses) and perceptual decision-making. By testing the same protocol across three cultures and latitudes, the study examines whether circadian match/mismatch effects on temporal cognition generalise across populations.

Detailed description

Background and rationale: Time perception is shaped by attention and physiological arousal, both of which follow a circadian rhythm that differs systematically between morning-type and evening-type individuals. The "synchrony effect" holds that performance is optimal when testing occurs at a person's circadian-preferred time. Whether this match/mismatch alters the perceived speed and precision of an internal clock, and whether any such effect generalises across cultures and latitudes, is not well established.

Design: a 2 (chronotype: morning-type vs evening-type; between-subjects) x 2 (session time: morning about 08:00 vs evening about 22:00; within-subjects, counterbalanced) mixed design, replicated at three sites. "Match" = tested at the circadian-preferred time; "mismatch" = tested at the non-preferred time. Site is included as an additional factor for generalisability.

Procedure: volunteers are screened online (Morningness-Eveningness Questionnaire to classify chronotype, with intermediate types excluded; Munich ChronoType Questionnaire; Pittsburgh Sleep Quality Index; demographics; colour-vision and health checks) and keep a 7-day sleep diary. Eligible participants attend two laboratory sessions and complete an identical battery each time: time-perception tasks (interval production/estimation, duration discrimination, passage-of-time judgement), state measures (sleepiness, mood, arousal), colour tasks (unique-hue settings with and without blue-blocking glasses; an ambiguous-colour image), a perceptual conformity task, and a vigilance task.

Primary hypothesis: a chronotype-by-time-of-day interaction on time-perception bias. Analysis uses linear mixed-effects models (participant as a random effect; chronotype, session time, their interaction, and site as fixed effects), with false-discovery-rate correction across secondary outcomes. Session order is counterbalanced to separate time-of-day from practice and order effects.

Interventions

• Behavioral Morning test session (about 08:00)
  Full perception and cognition battery administered shortly after habitual wake (about 08:00): time-perception tasks (interval production/estimation, duration discrimination, passage-of-time judgement), state measures (sleepiness, mood, arousal), colour tasks, a perceptual conformity task, and a vigilance task.
• Behavioral Evening test session (about 22:00)
  The identical battery administered late in the evening (about 22:00), enabling within-participant comparison of the same measures at the two times of day.

Primary outcome measures

• Time-perception bias measured by the two-alternative forced-choice duration-comparison point of subjective equality [Time frame: Each of two laboratory sessions, morning about 08:00 and evening about 22:00, completed within about 2 weeks.]

Secondary outcome measures (7)

• Temporal precision measured by the two-alternative forced-choice duration-discrimination Weber fraction [Time frame: Each of two laboratory sessions, morning about 08:00 and evening about 22:00, completed within about 2 weeks.]
• Subjective passage of time measured by a passage-of-time rating scale [Time frame: Each of two laboratory sessions, morning about 08:00 and evening about 22:00, completed within about 2 weeks.]
• Subjective sleepiness measured by the Karolinska Sleepiness Scale [Time frame: Each of two laboratory sessions, morning about 08:00 and evening about 22:00, completed within about 2 weeks.]
• Mood measured by the Multidimensional Mood Questionnaire [Time frame: Each of two laboratory sessions, morning about 08:00 and evening about 22:00, completed within about 2 weeks.]
• Unique-hue settings measured as hue angle in the Commission Internationale de l'Éclairage Colour Appearance Model 2016 (CIECAM16) [Time frame: Each of two laboratory sessions, morning about 08:00 and evening about 22:00, completed within about 2 weeks.]
• Ambiguous-colour image perception measured by forced-choice categorisation of the dress image [Time frame: Each of two laboratory sessions, morning about 08:00 and evening about 22:00, completed within about 2 weeks.]
• Perceptual conformity measured by change in perceptual judgement after social-response exposure [Time frame: Each of two laboratory sessions, morning about 08:00 and evening about 22:00, completed within about 2 weeks.]

Eligibility criteria

Inclusion criteria

• Healthy adult, 18-40 years
• Clear morning-type or evening-type on the Morningness-Eveningness Questionnaire (MEQ-SA); intermediate types excluded (state exact cut-offs, e.g. evening-type 41 or below, morning-type 59 or above)
• Normal or corrected-to-normal visual acuity
• Normal colour vision (e.g. Ishihara screening)
• Fluent in the testing-site language (Danish, Chinese, or English)
• Able to attend both an early-morning (about 08:00) and a late-evening (about 22:00) session

Exclusion criteria

• Intermediate chronotype (MEQ in the middle band)
• Night or rotating shift work in the past 3 months, or recent trans-meridian travel (more than 2 time zones in the past 4 weeks)
• Diagnosed sleep disorder (e.g. insomnia, sleep apnoea)
• Current psychiatric or neurological disorder
• Use of sleep medication or psychoactive or CNS-active drugs
• Colour-vision deficiency
• Substance-use disorder

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Open label

Primary purpose

Basic science

Study locations

Hong Kong · 1 center

• Child Development Centre — Hong Kong

Publications

• Kuriyama K, Uchiyama M, Suzuki H, Tagaya H, Ozaki A, Aritake S, Shibui K, Xin T, Lan L, Kamei Y, Takahashi K. Diurnal fluctuation of time perception under 30-h sustained wakefulness. Neurosci Res. 2005 Oct;53(2):123-8. doi: 10.1016/j.neures.2005.06.006. PMID 16039739
• Kuriyama K, Uchiyama M, Suzuki H, Tagaya H, Ozaki A, Aritake S, Kamei Y, Nishikawa T, Takahashi K. Circadian fluctuation of time perception in healthy human subjects. Neurosci Res. 2003 May;46(1):23-31. doi: 10.1016/s0168-0102(03)00025-7. PMID 12725909
• Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res. 1989 May;28(2):193-213. doi: 10.1016/0165-1781(89)90047-4. PMID 2748771
• Roenneberg T, Wirz-Justice A, Merrow M. Life between clocks: daily temporal patterns of human chronotypes. J Biol Rhythms. 2003 Feb;18(1):80-90. doi: 10.1177/0748730402239679. PMID 12568247
• May CP, Hasher L. Synchrony effects in inhibitory control over thought and action. J Exp Psychol Hum Percept Perform. 1998 Apr;24(2):363-79. doi: 10.1037//0096-1523.24.2.363. PMID 9554091
• Horne JA, Ostberg O. A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms. Int J Chronobiol. 1976;4(2):97-110. PMID 1027738

Identifiers

NCT: NCT07677111 · HSEARS20260622001

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗