Longevity, Ageing & Long-term Care

    Medical Treatment & Drug Development

    Mental Health & Neurology

Post-Doctoral Fellowships


Effects of light on cognitive performance, circadian markers, autonomic nervous system and sleep homeostasis in healthy elderly men and women with different PER3 genotypes

Scientists have proven that exposure to bright polychromatic light at night can increase alertness and cognitive performance. Dr. Antoine Viola is among the first to investigate how people react to exposure to bright light based on their genetic predisposition. The PER3 gene comes in two forms: people with the longer version are more affected by sleep deprivation. The results could provide a means to enhance alertness and performance, but also new treatments for certain sleep disorders.

Feeling sleepy? Go into the light!

In his own words...

The coding region of the clock gene, PER3, contains a variable number tandem repeat which has evolved in primates, with inter- and intra-specific length polymorphisms. In humans, we have reported the longer allele (five tandem repeats) to associate with morningness, and the shorter allele (four tandem repeats) with eveningness and delayed sleep phase syndrome . Findings from the most recent study have suggested that the association between diurnal preference and the PER3 polymorphism is strongest in young people (age 18-29) and attenuates with increasing age. My principal research focuses are on the circadian and sleep physiology of individuals possessing the homozygous type of PER3 polymorphism (PER3-4/4 or PER3-5/5) selected purely on the basis of genotype.

To add or modify information on this page, please contact us at the following address:



University of Basel





ORCID Open Researcher and Contributor ID, a unique and persistent identifier to researchers