Ongoing Projects  

Neurobiology of aging

vieillissementThe world’s population is aging. At the 2011 census, senior Canadians (65+ years) made up ~15% of the population, and this number is expected to reach ~30% within the next 25 years. Amongst the difficulties experienced by elderly adults, a highly prevalent and disabling problem is a decline in the ability to comprehend speech sounds in background noise, for example in the presence of multiple simultaneous talkers. Critically, speech perception difficulties reduce the effectiveness of communication as a whole and can lead to avoidance of social situations and isolation. Unfortunately, the causes of age-related speech perception difficulties are still unclear. While peripheral hearing impairments (“presbyacousy), which affects approximately 25-40% of adults over 65, lead to a reduced ability to comprehend speech, empirical evidence shows that age-related decline in speech perception can occur in the absence of peripheral hearing loss. Aging is also characterized by changes affecting speech production, though very little is known about the aging of speech production as well as the interplay between speech perception and production changes in aging.

Our aging research projects, funded by the FRQ-S and FRQ-SC, aim at identifying the underlying central neural mechanisms underlying changes in speech perception, speech production, voice, and hearing in aging. audiometryOur aging research focuses on several neurobiological factors that play a role the etiology of the changes that affect communicative skills, in particular, structural brain changes in regions involved in speech perception and production, functional brain changes in these regions, including the ability of the central nervous system to either sustain or counteract these changes through neural reorganisation (plasticity).

We are particularly interested in understanding the extent to which these neural changes affect
communication. (See Publications 2) Knowledge of the importance of specific regions is key to developing new rehabilitation therapies combining standard rehabilitation strategies with state-of-the-art brain stimulation such as transcranial magnetic stimulation (TMS) (which require selection of specific cortical targets), to either inhibit or enhance plasticity in these target areas to treat speech symptoms and enhance functional outcomes.

We are also interested in understanding the nature of the changes that affect the quality and stability of articulation, the intensity and pitch of voice, the rate at which speech is produced, and the error patterns in speech. We seek to understand the potential contribution of neuroanatomical and neurophysiological changes, as well as the contribution of changes in respiration, facial muscle patterns, muscle force and endurance to the ability to speak. Another goal of our aging research is to determine the extent to which age-related changes in speech and voice reduce communication intelligibility and efficiency and ultimately, whether these changes lead to reduced social participation and isolation. We are also interested in understanding the relationship between cognitive, auditory and sensorimotor aging, and aging of communication abilities.