Lotfi B. Merabet, O.D., Ph.D., MPH

Harvard Medical School

Associate Professor of Ophthalmology

Massachusetts Eye and Ear

Optometrist
Associate Scientist

Research Summary

Center/Research Area Affiliations

Biography

Dr. Merabet is a clinician scientist and a member of the Vision Rehabilitation Service at Massachusetts Eye and Ear. His research focuses on understanding how the brain adapts to the loss of sight. In the past, he has investigated the role of compensatory visual pathways using electrophysiological recording techniques in animal models. Currently, he uses advanced neuroimaging and noninvasive brain stimulation techniques to investigate the neuroplasticity of the visual system and mechanisms associated with sensory processing in individuals living with blindness and visual impairment. His recent work has concentrated on developing virtual environments and video game-based learning strategies for improving navigation and other cognitive skills in blind adolescents.

Download his CV or biosketch [PDF] for more information.

Education

Ph.D., Neuroscience, University of Montreal, Canada (1999)
O.D., New England College of Optometry (2001)
M.MSc., Clinical Investigation, Harvard-MIT Health Sciences Technology (2003)
M.P.H., Clinical Effectiveness, Harvard School of Public Health (2011)

Postgraduate Training

Postdoctoral Fellowship, Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center (2001-2003)
Postdoctoral Fellowship, Neuroimaging, Boston University and Mass General Hospital, Martinos Center for Biomedical Imaging (2003-2004)

Honors

2016: Low Vision Research Award, Research to Prevent Blindness
2015: Award of Distinguished Speaker, Principles and Practice of Clinical Research, Harvard Medical School
2014: Editor's Pick, TEDx Lecture Series
2011: Nominee, Young Mentor Award, Harvard Medical School
2002: Fellow, American Academy of Optometry
2001: Feinbloom Award for Excellence in Low Vision, New England College of Optometry
2001: Postdoctoral Fellowship Award, Canadian Institutes of Health Research (CIHR)

His Story

Dr. Merabet attended the University of Ottawa for his undergraduate degree in biology. He later earned a master’s in physiology at the University of Sherbrooke, a doctorate in neuroscience at the University of Montreal, a doctorate in optometry at the New England College of Optometry, and master’s degrees in both Clinical Investigation at HMS-MIT/HST and Public Health at Harvard. He has also completed two postdoctoral research fellowships in noninvasive brain stimulation (HMS/Beth Israel Deaconess Medical Center) and neuroimaging (Boston University/Mass General Hospital). He continues to lecture and serve as an advocate within the local blind community. He also serves on the Board of Directors at the Carroll Center for the Blind and National Braille Press.

Today, he studies individuals' adaptations to loss of sight and profound blindness. His main research interests include the development of assistive technology, and much of this work is done in local collaboration with the Carroll Center and Perkins School for the Blind, as well as internationally in Italy. His work is supported by the National Institutes of Health (NIH).

Projects

Research Interests

  • Development of assistive technology for individuals who are blind
  • Understanding how the brain adapts to the loss of sight (from ocular and brain-related causes)

Neuroplasticity and Compensatory Behaviors in the Blind

It is generally believed that individuals who are blind develop compensatory behavioral strategies through the use of their remaining senses. In some cases, it has been shown that the blind possess superior sensory abilities compared to the sighted (e.g., localizing sounds, discriminating tactile patterns, identifying smells, verbal memory recall). It is now well established that the development of these compensatory behaviors is intimately related to dramatic structural and functional changes occurring within the brain, termed “neuroplasticity.” Given that the brain is highly specialized, and that different regions of the brain are responsible for processing different sensory modalities, we can ask the question: “what is the fate of regions of the brain normally associated with the processing of visual information in an individual how is blind?" To answer this question, we employ a variety of specially designed stimulus presentation devices combined with behavioral sensory testing approaches and functional neuroimaging to uncover the functional contribution of different regions of the brain to non-visual forms of sensory processing.

Navigation Spatial Cognition and Video Game-Based Learning in the Blind

For those who are blind, learning to navigate is a very important skill to master in order to remain functionally independent in a world that is largely designed for the sighted. Researchers are considerably interested in virtual reality and computer-based video games as a means to motivate and improve contextual learning. At the same time, communication and entertainment industries have driven many technical advances (both software and hardware), such as high-speed and high-quality graphics, highly realistic sounds, and tactile and motion feedback joystick controllers with the aim of creating greater sense of environmental “immersion” for the user. Dr. Merabet and colleagues have developed user-centered, computer-based navigation software designed to help blind inviduals develop navigation skills through immersive virtual navigation. Using auditory spectral cues, a user navigates through a simulated virtual environment based on the spatial layout of an place for which they are unfamiliar. Following exploration, the user is able to transfer the knowledge gained regarding the spatial layout and navigate their way in the physical building model in the software.

Neuroplasticity Associated with Cortical Visual Impairment

Cortical visual impairment (CVI) is characterized by visual dysfunction primarily associated with damage to central cerebral structures rather than the eyes. In developed countries, CVI is the leading cause of permanent visual impairment in children. Despite this significant public health concern, it remains poorly understood. More research is needed to fully understand how the developing brain reorganizes itself in response to early damage. The goal of this investigation is to establish a conceptual framework relating sensory function with structural brain reorganization to better understand the underlying developmental neurophysiology of individuals with CVI. In this effort, we use high-resolution structural reconstruction and characterization of the white matter pathways of the brain using diffusion based imaging (specifically, High Angular Resolution Imaging, or HARDI).

Current Research Funding

2/1/10-1/31/19
National Eye Institute
Audio-haptic virtual environments for large-scale navigation in the blind
7/1/16-12/31/19 Research to Prevent Blindness/Lions Clubs International Foundation Low Vision Research Award
Characterizing the neurophysiology of cortical/cerebral visual impairment with combined structural and functional imaging

Publications

H-index

31 (Google Scholar, as of August 2017)

Selected Publications

Dr. Merabet has published more than 80 peer-reviewed articles and 13 text books, chapters, and monographs. Below is a list of selected publications. View his publications on PubMed, Google Scholar, or ORCID.

  1. Bauer CM, Hirsch GV, Zajac L, Koo BB, Collignon O, Merabet LBMultimodal MR-imaging reveals large-scale structural and functional connectivity changes in profound early blindness. PLoS One. 2017 Mar 22;12(3):e0173064.
  2. Martín MB, Santos-Lozano A, Martín-Hernández J, López-Miguel A, Maldonado M, Baladrón C, Bauer CM, Merabet LB. Cerebral versus Ocular Visual Impairment: The Impact on Developmental Neuroplasticity. Front Psychol. 2016 Dec 26;7:1958.
  3. Merabet LB, Connors EC, Halko MA, Sánchez J. Teaching the blind to find their way by playing video games. PLoS One. 2012;7(9):e44958.
  4. Merabet LB, Pascual-Leone A. Neural reorganization following sensory loss: the opportunity of change. Nat Rev Neurosci. 2010 Jan;11(1):44-52. 
  5. Pascual-Leone A, Amedi A, Fregni F, Merabet LB.The plastic human brain cortex. Annu Rev Neurosci. 2005;28:377-401.

Laboratory

Current Members of Dr. Lotfi Merabet's Laboratory

Instructor and Senior Research Fellow
Corinna M. Bauer, Ph.D.

Postdoctoral Fellow
Christopher R. Bennett, Ph.D.

Study Coordinator
Emma S. Bailin

Assistant Programmer
Timothy K. Gottlieb

Founder & CEO, Access to Places
Antonio Guimaraes

Collaborators and Friends

Perkins School for the Blind
Carroll Center for the Blind
National Braille Press
Boston University School of Medicine Center for Biomedical Imaging
University of Milano-Bicocca, Italy
University of Brescia, Italy
Project Prakash – Sinha Lab, MIT
Somers Lab, Boston University
Bex Lab, Northeastern University

Alumni

More than nine trainees have worked in Dr. Merabet’s laboratory. To view the complete list of alumni, download his CV [PDF].