Étude comparative des circuits neuronaux entre voyants et non-voyants utilisant simultanément l'IRM de structure et de diffusion

 

Hélène Nadeau

Centre de recherche en neuropsychologie et cognition (CERNEC)

 

Domaine : Neurosciences, santé mentale et toxicomanies

Programme Programme d'appui à la recherche pour les enseignants-chercheurs de collège

Concours 2016-2017

It is well-established that the brain is sufficiently adaptable that it can compensate for an individual's disability. For example, in blind people, those regions of the brain that are usually used for sight, in particular the occipital cortex, can be re-organized to process audio stimuli. Indeed, the compensation is such that blind people often have an enhanced sense of hearing compared to sighted people. However, the degree and type of adaptation greatly depends on the age of onset of blindness, and varies among individuals.

The goal of this project is to study the morphological differences between the brains of certain groups of blind and sighted people. In order to carry it out, we will use a computer program we recently developed. This program combines information from various magnetic-resonance images in order to compare the morphologies and neural circuits of the brains of different groups of people. We will compare three groups: those with early-onset blindness (blind before the age of five), those with late-onset blindness (became blind during adolescence or as adults), and those with normal sight. All were adults when the scans were performed. The determination of the morphological differences between the brains of the three groups will help us understand the adaptation mechanisms to sensorial deprivation.

Many types of treatment can increase the autonomy of a person with a visual disability. These include surgery on the optic nerve, the implant of a neuroprosthesis, etc. However, in order to maximize its effectiveness, the treatment must be compatible with the adaptation mechanism present in the brain. A deeper understanding of these mechanisms may therefore lead to improved medical treatments.