Circadian Timing and Time Perception in Healthy Adults

NCT07292597 | Recruiting DMC

• 2 other identifiers: 1-10-72-108-2510.46540/4256-00108B
• Study Type: interventional
• Target: 128
• Locations: 1 country
• Sites: 1

Brief Summary

This study examines how a person's natural daily rhythm ("chronotype") affects the way time is experienced and judged. Healthy Danish-speaking adults (23-45 years) who are clearly morning-type or evening-type will complete two lab sessions in a crossover design: one at their preferred time of day (e.g., morning for morning-types) and one at the opposite time (misaligned). In each session, participants do brief computerized tasks that measure time estimation/production, vigilance (psychomotor vigilance task), decision-making, and responses to social information, plus simple color-vision tasks. Short questionnaires about sleepiness, mood, fatigue, and the subjective "passage of time" are collected before, during, and after testing. A subset will wear a wrist actigraphy device for one week beforehand to characterize sleep-wake patterns. Testing is conducted under standardized lab conditions with scheduled breaks. The main goal is to determine whether time judgments and vigilance are less accurate during the misaligned session and whether decision-making and social responses also vary with circadian timing. Risks are minimal and mainly relate to temporary tiredness when tested at a non-preferred time; participants may stop at any time. Participation is voluntary. Data are pseudonymized and handled under GDPR. Participants receive DKK 300 after completing both sessions (pro-rated if they withdraw early). Results will be published regardless of outcome, and de-identified data/code will be shared after publication.This study examines how a person's natural daily rhythm ("chronotype") affects the way time is experienced and judged. Healthy Danish-speaking adults (23-45 years) who are clearly morning-type or evening-type will complete two lab sessions in a crossover design: one at their preferred time of day (e.g., morning for morning-types) and one at the opposite time (misaligned). In each session, participants do brief computerized tasks that measure time estimation/production, vigilance (psychomotor vigilance task), decision-making, and responses to social information, plus simple color-vision tasks. Short questionnaires about sleepiness, mood, fatigue, and the subjective "passage of time" are collected before, during, and after testing. A subset will wear a wrist actigraphy device for one week beforehand to characterize sleep-wake patterns. Testing is conducted under standardized lab conditions with scheduled breaks. The main goal is to determine whether time judgments and vigilance are less accurate during the misaligned session and whether decision-making and social responses also vary with circadian timing. Risks are minimal and mainly relate to temporary tiredness when tested at a non-preferred time; participants may stop at any time. Participation is voluntary. Data are pseudonymized and handled under GDPR. Participants receive DKK 300 after completing both sessions (pro-rated if they withdraw early). Results will be published regardless of outcome, and de-identified data/code will be shared after publication.

Conditions

Circadian Rhythm; Time Perception

Keywords

chronotype; circadian misalignment; duration discrimination; time production; time estimation

Outcome Measures

Primary Outcomes (1)

• Time estimation bias

  Signed percent error across 10, 30, and 60 s trials with a fixation cross: ((estimated - target)/target) × 100. Three trials per duration; session-level mean computed. Primary contrast: incongruent - congruent (within-subject). Higher values = overestimation.

  Day 1 (once during each of the two laboratory sessions: morning and evening)

Secondary Outcomes (6)

• Psychomotor Vigilance Task (PVT) lapses (count)

  Day 1 (once during each of the two laboratory sessions: morning and evening)

• Time production bias (neutral stimuli, 10-60 s)

  Day 1 (once during each of the two laboratory sessions: morning and evening)

• Duration discrimination threshold (2AFC adaptive)

  Day 1 (once during each of the two laboratory sessions: morning and evening)

• Subjective passage-of-time rating (VAS 0-100)

  Day 1 (pre-, mid-, and post-session ratings during each of the two laboratory sessions)

• Decision-making exploration rate (%) - Alien Game

  Day 1 (once during each of the two laboratory sessions: morning and evening)

Study Arms (2)

Sequence AB - Congruent → Incongruent

EXPERIMENTAL

rossover sequence AB. Participants first complete a circadian-congruent session (morning types in the morning; evening types in the evening), followed by a circadian-incongruent session (opposite time). Intervention administered: Behavioral - Session timing relative to chronotype.

Behavioral: Session timing relative to chronotype

Sequence BA - Incongruent → Congruent

EXPERIMENTAL

Crossover sequence BA. Participants first complete a circadian-incongruent session (opposite of their preferred time), then a circadian-congruent session. Intervention administered: Behavioral - Session timing relative to chronotype.

Behavioral: Session timing relative to chronotype

Interventions

Session timing relative to chronotype BEHAVIORAL

Two-period, two-sequence crossover manipulation of testing time. Each participant completes both sessions: (1) circadian-congruent timing (morning types tested in the morning; evening types in the evening) and (2) circadian-incongruent timing (opposite time). Session order is randomized (AB/BA). Sessions are run morning and evening on the same day with a substantial interval; no visible clocks; 12-h pre-session caffeine/strenuous-exercise restriction; standardized lab light/temperature. Primary outcomes: time-estimation/production bias and PVT lapses/RT.

Also known as: Circadian alignment, Circadian misalignment, Timing condition

Sequence AB - Congruent → Incongruent; Sequence BA - Incongruent → Congruent

Eligibility Criteria

• Age: 23 Years - 45 Years
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Aged 23 to 45 years
• Able to understand and communicate in Danish
• Completed at least upper secondary education (e.g., gymnasium)
• Categorized as either a Morning Type (MT) or Evening Type (ET) based on standardized chronotype assessments:
• Munich Chronotype Questionnaire (MCTQ):
• MT: sleep midpoint on free days (MSFsc) ≤ 03:00
• ET: sleep midpoint on free days (MSFsc) ≥ 05:00
• Morningness-Eveningness Questionnaire (MEQ):
• One of four defined chronotype categories (definitely morning, moderately morning, moderately evening, definitely evening).

You may not qualify if:

• Current engagement in shift work, rotating schedules, or other forms of irregular sleep-wake timing
• Diagnosis of any neurological, psychiatric, or sleep-related disorder (e.g., insomnia, narcolepsy, sleep apnea)
• Use of medications that affect sleep, alertness, or circadian functioning (e.g., melatonin, stimulants, antidepressants)
• International travel across time zones within the four weeks preceding study participation
• Are classified as having an intermediate chronotype based on validated chronotype assessments (MCTQ or MEQ), as this group does not provide the necessary contrast to evaluate circadian alignment effects.

Sponsors & Collaborators

• University of Aarhus: lead

Study Sites (1)

Cognition and Behavior Lab

Aarhus, 8000, Denmark

RECRUITING

Central Study Contacts

Ali Amidi, PhD

CONTACT

+45 87165305; ali@psy.au.dk

Cehao Yu, PhD

CONTACT

cehao.yu@psy.au.dk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Two-period, two-sequence (AB/BA) crossover. Each participant completes both sessions: circadian-congruent timing and circadian-incongruent timing. Session order is randomized; sessions occur morning and evening on the same day with a substantial interval and standardized pre-session restrictions.

Study Record Dates

• First Submitted: November 14, 2025
• First Posted: December 18, 2025
• Study Start: October 25, 2025
• Primary Completion (Estimated): April 30, 2027
• Study Completion (Estimated): June 30, 2027
• Last Updated: December 22, 2025

Record last verified: 2025-10

Locations

DK (1)