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Circadian RhythmChronoTimeNCT07292597

Circadian Timing and Time Perception in Healthy Adults

A study testing Session timing relative to chronotype in people with Circadian Rhythm and Time Perception, run by University of Aarhus at 1 site in Denmark.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial 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… Read more about this study

Who is it for?
Ages 23 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Circadian Rhythm, Time Perception
What is being tested?
Session timing relative to chronotype
Could I receive a placebo?
No, everyone receives an active treatment
How many people
128 participants
Where
1 siteDenmark
Study dates
25 Oct 2025to 30 Jun 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 23 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • 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
Show all 9Show fewer
  • 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).

Who cannot join

  • 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.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Ali Amidi, PhD contact

+45 87165305

ali@psy.au.dk

Cehao Yu, PhD contact

cehao.yu@psy.au.dk

Denmark1 site, 1 recruiting
  • Cognition and Behavior Lab

    Aarhus, 8000

    Mette Hejberg Pedersen, +45 9350 8899, cobelab@au.dk

    Recruiting

Other trials in Denmark

About this study

Official title: How Do Individual Differences in Circadian Rhythms Influence Time Perception?

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.

Read the detailed description

Background/Rationale. Circadian rhythms vary across individuals (chronotypes) and can be misaligned with social schedules. Both circadian timing and time perception influence cognition and behavior, yet within-person effects of circadian alignment on temporal judgments and related functions are not well characterized.

Objectives/Hypotheses. Primary: test whether circadian misalignment (testing at a non-preferred time) increases time-estimation/production bias and reduces vigilance versus aligned testing. Secondary: assess effects on temporal variability, duration discrimination, decision-making strategies, social conformity, and simple color-perception measures (white-point/unique-hue).

Design. Randomized, two-condition crossover trial with within-subject comparison of circadian-congruent vs incongruent sessions (order counterbalanced). Sessions occur on the same day (morning and evening) with a substantial break; no visible clocks; caffeine/exercise restrictions prior to testing. A subset (n≈60) completes 7-day actigraphy and sleep diary.

Participants. Healthy adults, 23-45 years, Danish-speaking, clear morning or evening chronotype (MEQ/MCTQ). Key exclusions: shift work, recent trans-meridian travel, sleep/neurologic/psychiatric disorders, medications affecting sleep/cognition, intermediate chronotype.

Intervention. Behavioral manipulation of testing time relative to chronotype (congruent vs incongruent) in a crossover design.

Outcomes.

Primary: (1) Time-estimation/production bias across 10-60 s targets; (2) Psychomotor vigilance task (lapses, RT).

Secondary: Time-estimation variability (CV), duration discrimination threshold, passage-of-time ratings, KSS sleepiness, mood/fatigue scales, information-conformity effect, decision-making metrics, color-perception indices (white-point/unique-hue).

Outcome time frame: per session; within-subject contrast (incongruent-congruent).

Sample size/Analysis. Target N≈128. Within-subject models test condition effects, with chronotype and session order as factors; missing data handled with mixed-effects models. Alpha=0.05 (two-sided).

Data management/Sharing. Pseudonymized data stored per AU policy/GDPR. De-identified datasets and analysis code will be shared in an open repository within 12 months of primary publication.

Risk/Benefit. Minimal risk (temporary tiredness). Potential benefits include improved understanding of circadian influences on cognition with implications for scheduling and performance.

Being tested
Session timing relative to chronotype
Keywords
chronotype, circadian misalignment, duration discrimination, time production, time estimation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Session timing relative to chronotypeBehavioural

    Also called Circadian alignment, Circadian misalignment, Timing condition

    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.

Study groups in NCT07292597
Study groupRoleWhat they receive
Sequence AB - Congruent → IncongruentExperimentalrossover 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.
Receives: Behavioral: Session timing relative to chronotype
Sequence BA - Incongruent → CongruentExperimentalCrossover 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.
Receives: Behavioral: Session timing relative to chronotype

What is being measured

The primary outcome is the main question the study is designed to answer.

  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.

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

Secondary outcomes (6)
  1. Psychomotor Vigilance Task (PVT) lapses (count)

    Number of lapses (reaction time > 500 ms) during a 10-minute PVT. Session-level count. Primary contrast: incongruent - congruent (within-subject). Secondary PVT metrics (median RT, 10% slowest RT) analyzed separately.

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

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

    Signed percent error for produced intervals vs targets (10, 30, 60 s). Three trials per duration; session-level mean. Contrast: incongruent - congruent (within-subject).

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

  3. Duration discrimination threshold (2AFC adaptive)

    JND (ms or % of standard) from a 2-interval, 3-down/1-up staircase with sub-second to few-second standards; session-level threshold. Contrast: incongruent - congruent.

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

  4. Subjective passage-of-time rating (VAS 0-100)

    VAS rating of "how fast time felt" collected pre/mid/post session; session-level mean or change from baseline. Contrast: incongruent - congruent.

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

  5. Decision-making exploration rate (%) - Alien Game

    Percent exploratory choices and total reward in a computerized multi-armed task; session-level metrics. Contrast: incongruent - congruent.

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

  6. Social conformity effect (% shifts toward majority)

    Proportion of responses shifted toward displayed majority opinion vs own baseline on perceptual judgments; session-level effect size. Contrast: incongruent - congruent.

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

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Dec 2025
  2. Study start25 Oct 2025
  3. Primary completion30 Apr 2027 (estimated)
  4. Study completion30 Jun 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Model description
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.
Masking
None (open label)
Enrolment
128 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07292597
Sponsor's protocol ID
1-10-72-108-25
Other IDs
10.46540/4256-00108B
Acronym
ChronoTime
Status last verified
Oct 2025
First submitted
14 Nov 2025
Last updated
22 Dec 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A study testing Session timing relative to chronotype in people with Circadian Rhythm and Time Perception, run by University of Aarhus at 1 site in Denmark.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 22 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Ali Amidi, PhD (+45 87165305, ali@psy.au.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Time estimation bias (time frame: Day 1 (once during each of the two laboratory sessions: morning and evening)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Dec 2025.

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