Le jeudi 16 janvier 2025, Madame Roya SHARIFPOUR, titulaire d’un Master in medical physics (Tehran University of medical sciences) et d’un Certificat de formation à la recherche en sciences biomédicales et pharmaceutiques, présentera l'examen en vue de l'obtention du grade de Doctorat en sciences biomédicales et pharmaceutiques, sous la direction de Monsieur Gilles VANDEWALLE.

Cette épreuve consistera en la défense publique d'une thèse intitulée : «Multimodal Investigation of Non-Image Forming Effects of Light on the Brain: Impact of Time of Day and Developmental Stage». 

Le jury sera composé de :

Pierre MAQUET (Président), BAHRI Mohamed Ali (Secrétaire), Christian CAJOCHEN (Univ. Basel), Valérie GOFFAUX (UCLouvain), Christophe PHILLIPS, Gilles VANDEWALLE.

Résumé de la thèse

Light exerts various non-image-forming (NIF) effects on human physiology and behavior, such as regulating circadian rhythms, mood, alertness, and cognitive function. These effects are largely mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs), which are particularly sensitive to blue-wavelength light. While the NIF effects of light are relatively well-established, the brain mechanisms behind these effects, as well as how they differ by age and time of day, remain unclear.

This thesis explores the NIF effects of light on the brain across adolescence and young adulthood, as well as at different times of day. Using a multimodal approach, including Transcranial Magnetic Stimulation coupled with EEG (TMS-EEG) and functional MRI (fMRI), we assessed the impact of blue light on cortical excitability and examined how blue-enriched light modulates regional brain activity (specifically in the hypothalamus) and functional connectivity among regions involved in an executive task.

Our findings reveal different responses to light between adolescents and young adults, as well as differences between morning and evening light exposure. These results highlight the importance of further research to deepen our understanding of how light influences brain function across different developmental stages and times of day, with the aim of optimizing light-based interventions.