PhD candidate in biomedical engineering (École Polytechnique)
Thesis : A calibrated fNIRS investigation of the impact of age related physiological changes on the preservation of semantic word processing
Description : With the growing demographic for elderly individuals in developed countries, the fields of neuropsychology of aging are of the utmost importance to understand age-related cognitive decline and encourage healthy aging. Functional near-infrared spectroscopy (fNIRS) has emerged recently as a new neuroimaging technique in fields of cognitive neurosciences because of its moderate running costs, portability and examinations in a natural setting. However, with aging, changes in measured hemodynamic response are not merely related to neuronal activity but also to modifications of the underlying physiology. Understanding the mechanism underlying semantic knowledge which has been proved by recent studies to be preserved well would help to comprehend the neurofunctional reorganization that allows the brain to maintain its cognitive abilities in face of some neurophysiological modifications. The protocol of this project is designed in an event-related fashion to investigate the neuronal activities underlying a semantic processing procedure evoked by a lexico-semantic decision task. The project takes profit from a multi-modal data acquisition consisted from anatomical MRI, Arterial Spin Labeling sequence (ASL) MRI, and time-domain optical imaging (TRS) in order to calibrate the functional fNIRS data by physiological and morphological changes observed in old population. This later augments the power of statistical inference and quantifies analysis in age group comparison.