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Impact of healthy aging on visual perceptual functions. A combined psychophysics and modeling study

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Directeur de thèse:
Doctorant: Daphne SILVESTRE
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Healthy aging alters all processing levels of the visual system, such as optics of the eye, retinal processing, early pre-attentive processing, and high-level attention-based processing. These alterations affect many visual functions such as visual acuity, contrast sensitivity, motion perception and visual attention.

The overall objective of this project is to characterize the age-related sensitivity losses on various visual functions and identifying the underlying functional and neurobiological alterations responsible for these perceptual losses. We will address these questions through experimental psychophysics by using the external noise paradigm, which enables the factorization of the sensitivity into internal equivalent noise and calculation efficiency. Our first objective is to characterize the effect of aging on cortical noise limiting contrast sensitivity at high spatial frequencies under bright conditions (e.g., daylight). The major aim of the study is to determine whether the effect of aging on a particular function is due to an increase in internal noise or a decrease in processing efficiency

This doctoral work is part of a larger research program, named SilverSight, carried out at the host laboratory Aging in Vision & Action led by A. Arleo at the Institute of Vision, Paris. The main strategic objective of SilverSight is to provide a unified characterization of how healthy aging shapes both sensory and cognitive aspects of visual perception and vision-based behavior. The adopted two-fold methodology (experiments and models) will offer a unique vantage point to generate a better understanding of the impact of normal aging across wide functional spectra and different organization levels. The ‘graying’ of the global population makes it increasingly urgent to stimulate knowledge-based sustainable solutions to the major societal challenge: accompany the elderly persons through accessible visual aids and rehabilitation protocols so as to meet their needs in a satisfactory, customized and appropriate manner, enhancing their healthcare treatment, autonomy and quality of life.