Les différences des corrélats neuronaux de l'encodage selon l'âge

 

David Maillet

Université Havard

 

Domaine : Vieillissement

Programme : Formation postdoctorale (citoyens canadiens ou résidents permanents)

Concours 2016-2017

Partenaire:

Réseau québecois de recherche sur le vieillissement (RQRV)

Current demographical trends predict that the proportion of elderly adults in Québec will increase in coming years. One of the most common complaints in the elderly is a reduction in the ability to encode (i.e. learn) and remember events from one's personal life. These memory losses impair older adults' daily functioning and can lead to detrimental health effects. It is thus critical to better understand age-related differences in memory functioning to help alleviate or reverse these negative effects. In the current project, we will use a state-of-the-art neuroimaging technique called functional magnetic resonance imaging (fMRI) to better understand the neurobiological correlates of memory in young (18-35 years) and older (60-80 years) individuals.

Contrary to initial predictions, research in this area has revealed that older adults do not simply activate brain regions to a lesser extent compared to their younger counterparts. Rather, while older adults do activate some specific brain regions of occipital cortex less than young (regions involved in visual perception), older adults also over-activate a different set of brain regions involved in internally-directed attention. In the current study, we will test the hypothesis that this overall pattern of altered brain activation reflects a shift in focus with increasing age: away from specific perceptual details (e.g. color, size, orientation, location of objects), and towards affective thoughts/feeling regarding the personal relevance or importance of ongoing events.

Such a result would highlight how previously reported age-related changes in brain activation in fMRI studies may reflect a change in focus with age, rather than a core memory deficit. This has implications on how memory is assessed in older adults and on methods aimed at improving memory in older adults.