Leonardo G. Cohen, M.D.

Senior Investigator

Human Cortical Physiology and Stroke Neurorehabilitation Section


Building 10, Room 7D54
9000 Rockville Pike
Bethesda, MD 20892



Research Topics

The goal of our activity is to understand the mechanisms underlying plastic changes in the human central nervous system (CNS) and to develop novel therapeutic approaches for recovery of function based on these advances. Our work has focused on the human motor system and on plastic changes taking place across sensory modalities for example in blind individuals (crossmodal plasticity). We have studied cortical reorganization in patients with CNS lesions in particular stroke and traumatic brain injury. In healthy volunteers, we studied cortical plasticity associated with deafferentation and motor skill learning.

We utilize different techniques in the context of well defined hypothesis-driven investigations including transcranial magnetic (TMS, video) and DC (tDCS) stimulation, fMRI, TMS in combination with fMRI, MR spectroscopy, diffusion tensor imaging (DTI), PET scanning and magnetoencephalography (MEG). We are interested in the development of these techniques to help us to understand mechanisms of human plasticity and to modulate human brain processes. Our research protocols in healthy volunteers are geared to identify mechanisms of human neuroplasticity and to develop interventional approaches to enhance them when they play a beneficial role and down-regulate them when they are maladaptive. Advances in this understanding in healthy volunteers are subsequently applied to patients with neurological conditions like stroke in attempts to enhance neurorehabilitative processes. In blind individuals, we seek to understand the mechanisms underlying the remarkable compensatory processes involved in crossmodal plasticity, and to facilitate them using noninvasive techniques.

Our future goals are to improve our understanding of mechanisms underlying plasticity of function in humans. On the basis of these insights, we are engaged in translational efforts to develop rational rehabilitative interventions to improve motor disability after stroke in particular using peripheral nerve stimulation, TMS and tDCS. In patients with severe hand paralysis, we use an MEG-based brain computer interface to control grasping motions of an orthosis attached to the paralyzed hand (video).


Dr. Cohen received his MD from the University of Buenos Aires. He did his neurology residency at Georgetown University and received postdoctoral training in clinical neurophysiology at the Department of Neurology, University of California (Irvine) and in motor control and movement disorders at the Human Motor Control Section, NINDS. In 1998 he became chief of the Human Cortical Physiology Section, NINDS. He received the prestigious Humboldt award (1999) from the Republic of Germany and is an elected member of the American Neurological Association. Dr. Cohen's lab is interested in the mechanisms underlying plastic changes in the human central nervous system and in the development of novel therapeutic approaches for recovery of function based on the understanding of these mechanisms.

Selected Publications

  1. Censor N, Horovitz SG, Cohen LG. Interference with existing memories alters offline intrinsic functional brain connectivity. Neuron. 2014;81(1):69-76.

  2. Saposnik G, Cohen LG, Mamdani M, Pooyania S, Ploughman M, Cheung D, Shaw J, Hall J, Nord P, Dukelow S, Nilanont Y, De Los Rios F, Olmos L, Levin M, Teasell R, Cohen A, Thorpe K, Laupacis A, Bayley M, Stroke Outcomes Research Canada. Efficacy and safety of non-immersive virtual reality exercising in stroke rehabilitation (EVREST): a randomised, multicentre, single-blind, controlled trial. Lancet Neurol. 2016;15(10):1019-27.

  3. Song S, Cohen LG. Practice and sleep form different aspects of skill. Nat Commun. 2014;5:3407.

  4. Censor N, Buch ER, Nader K, Cohen LG. Altered Human Memory Modification in the Presence of Normal Consolidation. Cereb Cortex. 2016;26(9):3828-37.

  5. Soekadar SR, Witkowski M, Cossio EG, Birbaumer N, Robinson SE, Cohen LG. In vivo assessment of human brain oscillations during application of transcranial electric currents. Nat Commun. 2013;4:2032.

This page was last updated on August 31st, 2017