Assistant Professor of Radiology Harvard Medical School

Associate Investigator Athinoula A. Martinos Center for Biomedical Imaging, Mass General Research Institute

brain mapping; event-related potentials, p300; evoked potentials, visual; pattern recognition, visual; perceptual masking; reaction time; recognition (psychology); visual cortex; visual perception

As a cognitive neuroscientist, my expertise is in using a variety of techniques, from psychophysics to event-related potentials (ERP), to functional MRI (fMRI), to study the function and organization of visual system in the brain. Currently, a large portion of my efforts are focused on studying fine-scale cortical structures within human visual cortex based on using high-resolution functional and structural imaging techniques in ultra-high field (7T) scanners.

The main goals of these studies are:

• To detect mesoscopic processing streams, usually not detectable by conventional neuroimaging techniques, that are involved in encoding fundamental visual features such as color, motion, shape and stereopsis (Nasr et al., 2016).
• To understand the link between the activity within these fine-scale streams and high-level visual capabilities such as object recognition and categorization.
• To understand the impact of statistics of natural scenes on organization of these fine-scale structures (Nasr and Tootell, 2016).

I am also involved in multiple projects in which my colleagues and I are studying the impact of neurodegenerative (e.g. Huntingtons disease), developmental (e.g. Amblyopia) and neuropsychological (e.g. Schizophrenia) disorders on cortical and subcortical visual processing.

The main goals of these studies is to highlight and understand the perceptual impairments in patients suffering from these disorders, and to assess their links to clinical symptoms such as abnormal social and/or cognitive behaviors (Nasr and Rosas, 2016).