Time Perception

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.

Perceiving and representing the passage of time allows us to temporally organize perceptions and memories for the coordination of actions, planning, and the mobilization of cognitive processes toward a goal. This innovative project aims to clarify the profile of time impairment associated with normal aging and the progression of age-related pathologies. This project proposes to develop a new neuropsychological tool for quantifying and preventing changes in the relationship to time associated with Alzheimer's disease. Four aspects of time are distinguished, which are measured separately and distributed along a continuum between perception and memory: (a) perception of simultaneity and order; (b) processing of durations; (c) subjective sense of the passage of time; and (d) mental time travel. Crucially, many neurological and psychiatric disorders are associated with impairment in one or more aspects of time. However, time remains largely unexplored in clinical practice. Patients with Alzheimer's disease will complete the CHRONOS battery. This battery allows for a rapid assessment (approximately ten minutes) of the four aspects of time. This new battery will enable the identification of behavioral markers aimed at improving prognosis and prevention regarding individual cognitive trajectories of aging. The relationship to time is closely linked to each person's personal experience. This project will help to put into words difficulties that are not always expressed in terms of time. Thus, considering these pathologies from the perspective of time aims to better understand and prevent their difficulties and to guide the identification of new markers and new avenues for remediation.

The purpose of this study is to investigate whether the experience of a daily time delay can affect our internal circadian rhythm.

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.

This study examines how the internal body clock (circadian rhythms) influences the way healthy adults experience time, think, and feel when they stay awake for an extended period. Participants will spend about 36 hours in a controlled sleep laboratory while remaining awake the entire time. Light, posture, food intake, and activity are kept as constant as possible (a "constant routine") so that changes over time mainly reflect the body's internal clock and increasing sleepiness, rather than changes in the environment. Every two hours, participants complete a brief test battery that includes ratings of sleepiness and mood, a reaction-time task, and short tasks that assess how fast or slow time seems to pass, how accurately they can estimate time intervals, how they respond to simple decisions, and how they judge colours. Saliva samples are collected repeatedly to measure melatonin, a hormone that indicates circadian phase. By comparing changes in behaviour, perception, and melatonin levels across the 36-hour wake period, the study aims to identify when during the circadian cycle people are most vulnerable to distortions in time perception and reduced alertness. The findings may help improve scheduling of shift work and other activities that require sustained wakefulness.

Premature neonates are able to discriminate phonemes and voice from 28wGA at a time the neuronal network establish contact between the environment and the cortical neurones. In the present monocentric study the investigators will analyse the response of the cortical network in premature aged between 25 and 36 wGA in response to auditory stimuli using High Resolution Electroencephalography and High Density Near Infrared Spectroscopy.

Premature neonates are able to discriminate phonemes and voice from 28wGA at a time the neuronal network establish contact between the environment and the cortical neurones. In the present monocentric study the investigators will analyse the response of the cortical network in premature aged between 28 and 40 wGA in response to auditory stimuli using High Resolution Electroencephalography and High Density Near Infrared Spectroscopy