Sook-Lei Liew, Ph.D., OTR/L

Sook-Lei Liew is an Assistant Professor at the University of Southern California in the divisions of Occupational Science and Occupational Therapy, Biokinesiology and Physical Therapy, and Neurology, a member of the Neuroscience Graduate Faculty, and Director of the Neural Plasticity and Neurorehabiltiation Laboratory. Prior to this, she completed a postdoctoral fellowship at the National Institute of Neurological Disorders and Stroke at the National Institutes of Health (NIH) and was a visiting fellow with Dr. Pablo Celnik at Johns Hopkins University. The goal of Dr. Liew’s research is to understand mechanisms of neural plasticity in healthy individuals and individuals after neurological injury in order to develop novel techniques for stroke rehabilitation, using neuroimaging, noninvasive brain stimulation, and behavioral approaches.

Ianessa Humbert, Ph.D.

Dr. Ianessa A. Humbert is an assistant professor of physical medicine and rehabilitation at the Johns Hopkins University School of Medicine. Her research focuses on swallowing disorders. Ianessa did her postdoctoral research fellow in swallowing neurophysiology at University of Wisconsin. She is a Speech-Language Pathologist specializing in swallowing neurophysiology.

Erik Hoyer, M.D.

Dr. Erik Hoyer is an assistant professor of physical medicine and rehabilitation at the Johns Hopkins University School of Medicine. His clinical interests include musculoskeletal and neurological rehabilitation, injection procedures to manage abnormal muscle tone (spasticity) and electrodiagnostic medicine (EMG).

Rachel Salas, M.D.

Rachel is a board certified sleep neurologist. She is interested on the physiological mechanisms underlying sleep disorders. She is an Associate Professor in the Dept. of Neurology.

Post-Doctoral Fellows

Robert Hardwick, Ph.D.

Robert completed his PhD at the University of Birmingham (UK) with Dr Martin Edwards in 2010, before moving on to work in the Predictive Sensorimotor Laboratory with Professor Chris Miall. In 2012 he moved to Johns Hopkins as a research fellow in the Human Brain Physiology and Neurostimulation laboratory with Dr Pablo Celnik, and joined the Brain, Learning, Movement, and Animation laboratory in 2014.

Panagiotis Kassavetis, Ph.D

Dr Panagiotis Kassavetis completed his MD degree at Athens Medical School, Greece. He then pursuit MSc and PhD degrees at the UCL, Institute of Neurology, London, UK. His research interests focus on human movement physiology and pathophysiology. During a 6-month post-doctoral fellowship at Dr Celnik’s lab he completed a project on the effects of muscle fatigue on motor learning. He is now a Neurology resident at Boston University.

Mary Gregory, Ph.D.

John Schlerf, Ph.D.

John earned his Ph.D. in Neuroscience from University of California, Berkeley. He studied how the cerebellum helps produce accurate movements. He currently works at eBay Advertising.

Hannah Block, Ph.D.

Hannah is an assistant professor of Kinesiology at Indiana University School of Public Health. Hannah earned her Ph.D. in Neuroscience from Johns Hopkins University in 2009. Hannah uses behavioral and neurophysiological techniques to study the neural basis of these compensatory sensorimotor processes in healthy adults.

Joseph M. Galea, Ph.D.

Originally from the United Kingdom, Joe graduated from the lab of Chris Miall. He is currently a Senior Research Fellow in Professor John Rothwell’s lab at UCL.

Jeffrey Willis, M.D., Ph.D.

Jeff earned his M.D. from University of Maryland and his Ph.D. from Johns Hopkins University. He is currently an Internal Medicine intern at GBMC and will start his Ophthalmology residency at UC Davis in 2012. Jeff is interested in the effects of action observation on motor training in chronic stroke patients and on low vision rehabilitation.

Nicholas Wymbs, Ph.D.

Nick joined the lab after receiving his Ph.D. in Psychology from UCSB working in Scott Grafton’s lab. He is interested in the diverse mechanisms that we use every day to tackle both novel learning situations and support the retrieval and modification of well-known behaviors. He uses a diverse set of tools (behavioral analysis, non-invasive stimulation, neuroimaging) to understand skill learning in both the healthy and the diseased brain.



Ph.D. Students

Gowri Jayaram, Ph.D

Gowri recieved her Ph.D from Johns Hopkins in 2013. Gowri graduated from Northwestern University with a B.S. and M.S. in Biomedical Engineering after doing research at the Rehabilitation Institute of Chicago. She currently works as an associate at McKinsey & Company.

Claudia Ammann

Claudia is originally from Germany and graduated from the Pablo de Olavide University (Seville) with a B.S. in Environmental Sciences and an M.S. in Neuroscience and Behavorial Biology. She completed a rotation studying learning and non-invasive brain stimulation in animal models. She plans on completing a post-doc in Dr. Celnik’s lab upon completing her PhD.


Masters Students

Vikram Rajan, M.S.


Research Assistants

Joel Ramirez


Sara Tankard


Neel Pasricha, B.A.

Neel graduated from Johns Hopkins University with a B.A. in Neuroscience. He is currently attending medical school in Duke University.

Loni Ajagbe, B.A.

Loni graduated from Dartmouth University with a B.A. in Neuroscience. She is currently completing a MPH at Johns Hopkins University.

Byron Tang, B.S.

Byron graduated from Johns Hopkins University with a B.S. in Biomedical Engineering. He worked with Dr. Bastian while earning his B.S. and transitioned to working with Dr. Celnik upon graduation. Byron is currently working as a Business Analyst for BTS in San Francisco.

Tziporah Thompson

Tziporah received her Bachelor’s in Neuroscience from Brandeis University in 2014. Previous work with Dr. Reggie Edgerton at UCLA involved studying the effects of spinal cord stimulation in the locomotion of full spinal rats. She is currently pursuing a career in medical illustration at the Medical and Biological Illustration Graduate Program at Johns Hopkins .


Samiran Bhattacharya, M.D.

Samiran graduated from Duke University with a B.S. in Biology, and graduated from Johns Hopkins University School of Medicine.  After completing a preliminary internship year at the University of Maryland he is currently applying for residency in Physical Medicine and Rehabilitation.