John Assad

John Assad, Ph.D.

Professor of Neurobiology, Harvard Medical School

Director of the Harvard Program in Neuroscience, Harvard Medical School

617-432-2804

Assad Lab Website

Research
Publications

Open the John Assad faculty profile graphic in Canva (opens in a new tab)

John Assad, PhD

Professor of Neurobiology
Department of Neurobiology, Harvard Medical School
Director, Harvard Program in Neuroscience

Email: john_assad@hms.harvard.edu
Website: Assad Lab website – more information about John Assad’s research (opens in a new tab)

The Aim

The Assad lab studies how the brain decides when to initiate voluntary movement.

The Impact

Our lab studies how the brain decides when to move. While most research has focused on reactions to outside events, we are interested in what triggers self‑initiated actions by investigating how different brain regions and cell types contribute to this process. This has implications for people who struggle to start movements on their own, such as is the case in those with Parkinson’s disease.

A Closer Look

Quanta Magazine – December 2021: Dopamine and the timing of voluntary movement (article, opens in a new tab)

Quanta covered Assad’s discovery that dopamine, known mainly as a reward signal, slowly builds in the seconds before a mouse makes a voluntary movement, with its rate of rise predicting almost exactly when the animal will act. This finding has direct implications for Parkinson’s disease, in which self‑initiated movement is disrupted.

Harvard Griffin GSAS – July 2021: Exploring the mechanisms that underlie the timing of movement (article, opens in a new tab)

A Harvard profile on Assad and a PhD candidate in his lab explores the mechanisms that underlie the timing of movement. Their research revealed that dopamine neurons may function as the brain’s “go” signal for voluntary action.

Publications View

A mechanism linking dopamine's roles in reinforcement, movement and motivation.

Authors: Authors: Hamilos AE, Wijsman IC, Ding Q, Assawaphadungsit P, Ozcan Z, Assad JA.
bioRxiv 2025-04-05
View full abstract on Pubmed

Explaining dopamine through prediction errors and beyond.

Authors: Authors: Gershman SJ, Assad JA, Datta SR, Linderman SW, Sabatini BL, Uchida N, Wilbrecht L.
Nat Neurosci 2024-07-25
View full abstract on Pubmed

Slowly evolving dopaminergic activity modulates the moment-to-moment probability of reward-related self-timed movements.

Authors: Authors: Hamilos AE, Spedicato G, Hong Y, Sun F, Li Y, Assad J.
Elife 2021-12-23
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Neuronal Mechanisms of Visual Categorization: An Abstract View on Decision Making.

Authors: Authors: Freedman DJ, Assad JA.
Annu Rev Neurosci 2016-07-08
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Instituting recruiting meritocracy in Italy.

Authors: Authors: Assad J.
Science 2016-04-22
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Multipoint-emitting optical fibers for spatially addressable in vivo optogenetics.

Authors: Authors: Pisanello F, Sileo L, Oldenburg IA, Pisanello M, Martiradonna L, Assad JA, Sabatini BL, De Vittorio M.
Neuron 2014-06-18
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Neuroscience: Updating views of visual updating.

Authors: Authors: Assad JA.
Nature 2014-03-27
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Relative timing: from behaviour to neurons.

Authors: Authors: Aghdaee SM, Battelli L, Assad JA.
Philos Trans R Soc Lond B Biol Sci 2014-03-05
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Visuomotor adaptation changes stereoscopic depth perception and tactile discrimination.

Authors: Authors: Volcic R, Fantoni C, Caudek C, Assad JA, Domini F.
J Neurosci 2013-10-23
View full abstract on Pubmed

Biased associative representations in parietal cortex.

Authors: Authors: Fitzgerald JK, Freedman DJ, Fanini A, Bennur S, Gold JI, Assad JA.
Neuron 2013-01-09
View full abstract on Pubmed