Le lundi 18 mars 2024, Madame Islay CAMPBELL, titulaire d'un Master of 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 : 

"Investigating the biological impact of light on brain function using 7T ultra high field MRI".

Le jury sera composé de :

Christine BASTIN (Présidente), Christophe PHILLIPS, Yvonne KORT (Univ. Eindhoven), Steve MAJERUS, Nina MILOSAVLJEVIC (Univ. Manchester), Christina SCHMIDT, Gilles VANDEWALLE

Résumé de la thèse

It is starting to be established that our light environments can influence our health and wellbeing with several health issues being associated with aberrant lighting. The human retina detects environmental irradiance through the non-image forming (NIF) system, which is maximally sensitive to the shorter blue wavelength of visible light (~480nm). This system mediates light influence on several circadian, neuroendocrine, and neurobehavioral functions. Energy-efficient white light-emitting diodes are a common form of lighting and are a blue-enriched light sources with a peak around 440–460 nm.

The brain circuitry underlying light’s stimulating impact is not yet established in humans. To understand how the NIF impact of blue-enriched light may influence the brain functions, we utilised two techniques, ultra-high-field 7 Tesla functional magnetic resonance imaging and infrared eye tracking equipment. Young healthy adults completed an fMRI scan with simultaneous eye tracking whilst exposed to light of various illuminance and engaged in auditory cognitive tasks. In my thesis, we found that light illuminance influences the task-evoked pupil response associated with auditory inputs, presumably through the recruitment of the locus coeruleus. Also, there are regional differences to light illuminance across the human hypothalamus and amygdala whilst engaged in cognitive tasks.