When: 19 February 19 2021, 11h00
Where: Visioconference (Zoom link here)
Speaker: Dr. Stephen Ramanoël (website)
Institutions
- UCA, LAMHESS, Nice, France
- Sorbonne Universités, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France
- Université Grenoble Alpes, CNRS, LPNC, 38000 Grenoble, France
- Université Grenoble Alpes, INSERM, CHU Grenoble, GIN, 38000 Grenoble, France
Title: The neural correlates of visuo-spatial information processing in healthy and pathological aging
Abstract: The 21st century is marked by a demographic “graying” of the global population. In this context, spatial navigation as a complex behavior encompassing perceptual, cognitive and motor processes, provides an ideal framework for the study of normal and pathological aging. Older adults exhibit prominent impairments in their capacity to navigate efficiently, reorient in unfamiliar environments or update their path when faced with obstacles. These changes in navigation capabilities reduce older adults’ autonomy and mobility, resulting in an increased risk of progression of age-related disorders such as Alzheimer’s disease. This decline in navigational capabilities has traditionally been ascribed to memory impairments and dysexecutive function whereas the impact of visual aging has often been overlooked. The ability to perceive visuo-spatial information such as the overall layout of an environment or the salient landmarks it contains is essential to navigate in space efficiently. To date, the functional and neurobiological factors responsible for the deterioration of visuo-spatial functions in healthy and pathological aging remain insufficiently characterized. To address this issue, we implemented a highly interdisciplinary approach, bringing together clinical, psychophysical and behavioral assessments as well as neuroimaging paradigms combining morphometric measurements, connectivity analyses, functional magnetic resonance imaging (fMRI) and virtual reality. During this seminar, I will present some experimental results from young and healthy older participants as well as from AMD patients using an integrative approach from passive perception of visual scenes to active navigation tasks. This work helps towards a better comprehension of the neural dynamics subtending visual and navigation processing and it provides new insights for the development of innovative remediation methods, such as visual devices or spatial environment designs, in order to improve the autonomy and healthcare of these populations.
Short bio: I completed a first Master’s degree in Sport Sciences at the University of Grenoble, France, and a second Master’s degree in Cognitive Sciences at the Institut National Polytechnique de Grenoble. I then worked as a research engineer on functional magnetic resonance imaging (fMRI) in monkeys at the Neurosciences Cognitive Center (Lyon, France) for one year. In 2015, I obtained my PhD in Cognitive Sciences from the University of Grenoble Alpes under the supervision of Carole Peyrin (LPNC) and Michel Dojat (GIN). My thesis focused on the study of perception and cognition in the human brain using psychophysics and neuroimaging approaches. More specifically, I investigated (i) the retinotopic organization of spatial frequency processing in the visual cortex and (ii) the brain plasticity in normal and pathological aging (aged-related macular degeneration) using fMRI associated with retinotopic mapping. In addition, my thesis included methodological developments linked to the acquisition and the processing of fMRI data for clinical applications. In February 2016, I joined the Aging in Vision and Action laboratory at the Vision Institute in Paris as a postdoctoral fellow. I studied the impact of healthy aging on the cerebral bases of visual processing and spatial cognition using fMRI. In 2020, I realized a short postdoctoral internship at Genève University to investigate the cerebral bases of the need of autonomy. I recently joined the University Côte d’Azur as an associate professor of Psychology, Cognitive Neuroscience and Sport Sciences. My current research focuses on the impact of healthy aging on the cerebral bases subtending visual processing and spatial cognition. The methodological approach is highly interdisciplinary, bringing together clinical, psychophysical and behavioral assessments as well as neuroimaging paradigms and virtual reality. I am also very interested in advanced MRI data processing (pre-processing and statistical modelling) as well as optimization methods.
Keywords: Spatial frequency, Visual perception, Healthy aging, AMD patients, Spatial cognition, fMRI, MRI, Connectivity, Retinotopic mapping, Virtual Reality.
