In this talk, we will present our recent developments in the context of Personalized functional Near Infra-Red Spectroscopy (fNIRS) investigations, which consist in optimizing placement of fNIRS sources and detectors on the head of the participant in order to maximize fNIRS sensitivity to some targeted brain regions, while allowing accurate local 3D reconstructions of fluctuations of oxy-hemoglobin and deoxy-hemoglobin along the cortical surface. Personalized fNIRS investigations could be ...