Time processing, the ability to process and encode temporal information, is essential for cognitive functioning and for a large number of daily life activities. In particular, the processing of durations of several seconds is central to cognition, impaired in several pathologies, and has been associated with cognitive changes with advancing age. While behavioral studies have been conducted to specify the neural bases of temporal cognition and their association with other cognitive functions, the mechanisms underlying age-related changes, and individual differences, remain unknown. The project will characterize ageing effects on timing mechanisms and their neural underpinnings. Building on recent advances from neuroscience and age-related cognitive changes, the project focuses on the precision of duration processing, that declines with age, and the associated neural bases. Participants will perform a duration judgement task while (a) electroencephalography, and (b) functional magnetic resonance imaging activity are simultaneously recorded to investigate age effects on structural and functional network connectivity. In addition, striatal dopamine will be measured using a FDOPA PETscan. Evaluation of other temporal cognition processes and general cognition will also be performed. This combination offers a unique opportunity to accurately specifying the neurophysiological underpinning of aging effects on time processing changes. This project will further our understanding of the variability of cognitive performance with advancing age, and contribute to identifying new measures of temporal impairments.
Membership of a social security scheme or beneficiary of such a scheme.
At least 7 years' schooling.
Acceptance and signature of the informed consent form
Fluency in French (as assessed by the project leader)
Persons under guardianship, curators or safeguard of justice.
Pregnant women, women in labor and nursing mothers
Chronic neurological conditions
Uncorrected visual difficulties
Healthy participant with no diagnosed condition
Case-control
Prospective
FDOPA injection before PET imaging
RadiationFluorodopa labelled with fluorine 18 (physical half-life of 109.6 min) is used at a dosage of 1 to 2 MBq/kg in neuroimaging, depending on the sensitivity of the PET camera used. For these reasons, a dose of 2 MBq/kg will be administered slowly intravenously (approximately 1 minute for a maximum bolus of 10 mL). PET acquisitions will be performed at 90 minutes post-injection and will last 30 minutes. Participants will be asked to have fasted for at least 4 hours at the time of injection, with no restriction on fluid intake.
Time perception tasks
BehavioralThe main tasks involves the comparison of duration to assess aging effects on the precision of temporal representations
fMRI imaging
DeviceImaging of brain structure during the completion of the time perception task
EEG imaging
DeviceRecording of neural dynamics during the completion of the time perception task
3 year follow-up
BehavioralBehavioral and EEG follow-up (for older adults only)
EEG phase lag index differences between group
Functional connectivity (EEG phase lag index (PLI) in each frequency band) differences between young and older adults during completion of the duration comparison task
Click on the lead sponsor to view all of their trials.
