Periodic Reporting for period 3 - COGNAP (To nap or not to nap? Why napping habits interfere with cognitive fitness in ageing)
Periodo di rendicontazione: 2021-01-01 al 2022-06-30
In parallel to data acquisition, the team participated to several congresses (see list below) and developed tools for data processing, the first of which was recently submitted for publication in a peer reviewed journal (paper on the PyActigraphy Toolbox: http://doi.org/10.5281/zenodo.2537921).
Even though our project is based on group comparisons which should be computed at final sample size, we started to run first proof-of concept analyses
WP01. Circadian ranking of the participants. As expected we observe a clear circadian profile of average time course of subjective sleepiness, psychomotor vigilance performance (all participants averaged) and melatonin data (available for first 10 participants so far). To proceed to ranking as explained in the project, melatonin data need to be analyzed for the entire participant pool.
WP2: Phenotyping cognitive and brain fitness. By waiting access to the full-set of in lab measures in the lab and before being able to proceed to group comparisons, we estimated circadian disruption using field actimetry indices and observed that these indices significantly explain variance on a memory and attention performance composite score, such that lower performance is associated with higher sleep-wake fragmentation. In that sense, our data corroborate an association between sleep-wake cycle fragmentation and cognition in the aged.
Functional imaging: By waiting access to the full-set of in lab measures in the lab, we estimated circadian disruption using a field actimetry indices. Preliminary analyses suggest under-recruitment in task-relevant superior parietal regions in individuals characterized by higher wake fragmentation.
WP3. Interventional approach. Nap suppression will effectively improve circadian organization and thereby optimize cognitive fitness in the aged. These data have not yet been processed in depth. Nevertheless, a preliminary analysis indicates that that after 6 month follow-up, the nap intervention group felt less negative affect as assessed by the PANAS (positive-negative affect) scale at follow up compared to their baseline measurement.
These preliminary outcomes will be presented at the 25th Congress of the European Sleep Research Society, which will be held from September 22th-25th 2020.