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Reza Shadmehr

@rezashadmehr.bsky.social
817 followers 752 following 87 posts

Father, husband, scientist

PostsRepliesMedia
Reza Shadmehr @rezashadmehr.bsky.social · 02/10/2026
How hard it is to get a grant these days? NIH funding rates in 2025 have fallen to the lowest in 30 years. (This graph combines established investigators with at-risk investigators, as defined by NIH).
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Reza Shadmehr @rezashadmehr.bsky.social · 22/09/2026
Faculty position opening in computational neuroscience at Duke University. academicjobsonline.org/ajo/jobs/32697
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Reza Shadmehr @rezashadmehr.bsky.social · 20/09/2026
How does cerebellar output interact with motor cortex and basal ganglia to support goal-directed behavior? Dimitar Kostadinov will present. Talks are open to all (email me for link) Recorded talks: youtube.com/@shadmehrlab
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Reza Shadmehr @rezashadmehr.bsky.social · 28/08/2026
How does the brain know when to act? Hidehiko Inagaki will present neural mechanisms that allow animals to time self-initiated movements, and how learning rewires circuits to adjust this internal timer. A fascinating look at how the brain turns intention into action.
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Reza Shadmehr @rezashadmehr.bsky.social · 23/08/2026
Tranquility.
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Reza Shadmehr @rezashadmehr.bsky.social · 28/07/2026
If an action results in error, each neuron requires an individualized teaching signal that guides change in its output. This is the credit assignment problem of learning. Are there neurons in the brain that can compute such a sophisticated teaching signal? Yes. www.biorxiv.org/content/10.6...
biorxiv.org
Climbing fibers encode the gradient of a loss function for the cerebellum
Neurons in the brain are often many synapses away from motoneurons, yet if a movement results in error, each distant neuron needs a teacher that considers its specific contribution to production of th...
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Reza Shadmehr @rezashadmehr.bsky.social · 19/06/2026
www.youtube.com/watch?v=IW-6...
youtube.com
How the Brain Predicts the Future | Prof. Reza Shadmehr
YouTube video by Wandering Thoughts
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Reza Shadmehr @rezashadmehr.bsky.social · 15/03/2026
Today I received a note from a grad student who lives in Tehran. Her note gives you firsthand experience of what it’s like to live in a city that is being bombed, and what it’s like to be young and feel despair about your future. rezashadmehr.blogspot.com/2026/03/hope...
rezashadmehr.blogspot.com
Hopeless in Tehran
Essays on neuroscience
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Reza Shadmehr @rezashadmehr.bsky.social · 26/02/2026
80% of the neurons in our brain are in the cerebellum, and most of those are granule cells. What are these cells doing and why do we need so many of them? David DiGregorio will explain. The talks are open to all (contact me for link). Recorded talks: www.youtube.com/@shadmehrlab
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Reza Shadmehr @rezashadmehr.bsky.social · 16/02/2026
NeuroBridges brings together students from the countries of the middle east to learn about the brain, and each other. Applications are now open. neurobridges.net/upcoming
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Reza Shadmehr @rezashadmehr.bsky.social · 16/02/2026
Mark Goldman will present computational models of interacting cortical and nuclear plasticity and propose a metaplasticity mechanism that adaptively tunes spike-timing-dependent plasticity at the parallel fiber–Purkinje cell synapse. This is a zoom talk: all are welcome
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Reza Shadmehr @rezashadmehr.bsky.social · 04/02/2026
Citing reduced federal funding, Johns Hopkins is exploring new low cost student housing.
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Reza Shadmehr @rezashadmehr.bsky.social · 25/01/2026
Aleksandr Solzhenitsyn: “One should never direct people towards happiness, because happiness is an idol of the marketplace. One should direct them towards mutual affection...only human beings can feel affection for each other, and this is the highest achievement they can aspire to.”
Image credit: https://unsplash.com/photos/man-holding-card-with-seeking-human-kindness-text-8UG90AYPDW4
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Reza Shadmehr @rezashadmehr.bsky.social · 22/01/2026
Autism is a disorder that particularly affects the cerebellum. Synaptic protein abnormalities appear to underlie disrupted development, potentially resulting in cognitive symptoms. The recorded talks are available here: www.youtube.com/@shadmehrlab...
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Reza Shadmehr @rezashadmehr.bsky.social · 20/01/2026
Neurobridges is a summer school that brings together students from the middle east, teaching them about synapses and circuits, but hoping to build understanding. Here is a little essay about some of the conversations that took place in 2025. rezashadmehr.blogspot.com/2026/01/neur...
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Reza Shadmehr @rezashadmehr.bsky.social · 10/01/2026
The fastest inhibitory connection in the brain appears to be via a basket of axons electrically acting to inhibit Purkinje cells. The seminars are open to all (please contact me for link).
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Reposted by Reza Shadmehr
Jonathan Tsay @tsay.bsky.social · 08/01/2026
Happy New Year, everyone! Excited to share that our paper, “Goal uncertainty attenuates sensorimotor adaptation,” is now published in the Journal of Neurophysiology. Huge thanks to our collaborators—Sritej, Bobby, and Reza @rezashadmehr.bsky.social. Paper: tinyurl.com/yyfast5m
tinyurl.com
Goal uncertainty attenuates sensorimotor adaptation | Journal of Neurophysiology | American Physiological Society
Implicit sensorimotor adaptation—the automatic correction of movement errors—is driven by a perceptual prediction error, the mismatch between the perceived movement outcome and its intended goal. Alth...
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Reza Shadmehr @rezashadmehr.bsky.social · 01/01/2026
My group of explorers, aiming to chart the cerebellum in 2026.
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Reposted by Reza Shadmehr
Paul Gribble 🇨🇦 @gribblelab.org · 17/12/2025
Are you interested in a MSc/PhD in human sensorimotor neuroscience? Learn to design experiments, analyze data, read & write papers, present at conferences, & work with a vibrant group of students & faculty in a world-class research environment. #neuroskyence #psychscisky gribblelab.org/join.html
gribblelab.org
Paul Gribble PhD
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Reza Shadmehr @rezashadmehr.bsky.social · 10/12/2025
Monogamy appears to coincide with the rise of cooperative society. But how monogamous are humans? DNA analysis suggests that humans are more monogamous than many other mammals, but unlike others, we live in groups in which multiple male-female pairs are monogamous and breed. tinyurl.com/mryrnufc
tinyurl.com
Human monogamy in mammalian context
Abstract. Monogamy has been argued to have played an important role in human evolution and, across animals more generally, evolutionary transitions to high
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Reza Shadmehr @rezashadmehr.bsky.social · 08/12/2025
We tend to think of neurons as either excitatory or inhibitory, but some neurons chemically inhibit their downstream targets while electrically exciting their neighbors. What is gained by having an inhibitory neuron excite its neighbor? www.biorxiv.org/content/10.6...
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Reza Shadmehr @rezashadmehr.bsky.social · 05/12/2025
Some forms of episodic ataxia are caused by mutations in the gene that encodes a calcium channel. Currently, no medications exist to treat it. Heather Snell presents new results on a potential therapeutic target for episodic ataxia. The seminars are open to all (contact me for zoom link).
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Reza Shadmehr @rezashadmehr.bsky.social · 28/11/2025
A study finds that cats meow harder to greet their male caregivers than female. Females are more verbally interactive, more skilled at interpreting cat meows. Apparently males require more meows to notice and respond to the needs of their cats. onlinelibrary.wiley.com/doi/10.1111/...
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Reza Shadmehr @rezashadmehr.bsky.social · 22/11/2025
Tenure track position in motor control at Northeastern University northeastern.wd1.myworkdayjobs.com/careers/job/...
northeastern.wd1.myworkdayjobs.com
Open Rank (Professor, Associate or Assistant) AI, Sensors, and Human Movement
About the Opportunity About Northeastern Founded in 1898, Northeastern is a global research university and the recognized leader in experience-driven lifelong learning. Our world-renowned experiential...
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Reza Shadmehr @rezashadmehr.bsky.social · 21/11/2025
Shadows of our lab mates as the sun sets over San Diego and SFN comes to an end.
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Reza Shadmehr @rezashadmehr.bsky.social · 15/11/2025
At SFN in San Diego.
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Reza Shadmehr @rezashadmehr.bsky.social · 09/11/2025
Our intelligence and cognitive abilities are perhaps due to an expansion of our cerebral cortex. But surprisingly, compared to highly intelligent birds, primates have many more neurons in their cerebellum as compared to the cerebral cortex. doi.org/10.1073/pnas...
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Reza Shadmehr @rezashadmehr.bsky.social · 07/11/2025
The bird branch of evolution separated from mammals hundreds of millions of years ago. Yet, their cerebellum has the same structure as ours, including the zebrin bands. Here is the cerebellum of the zebra finch and the most amazing flyer of them all, the hummingbird. doi.org/10.1159/0005...
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Reza Shadmehr @rezashadmehr.bsky.social · 07/11/2025
Birds are both intelligent and incredibly agile, yet they are quite small. How do they achieve this with their little brains? They have twice as many neurons per brain mass than mammals, including primates. www.pnas.org/doi/abs/10.1...
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Reza Shadmehr @rezashadmehr.bsky.social · 04/11/2025
George Washington wrote to a Jewish congregation in Rhode Island that the United States was founded not on “toleration … as if it was by the indulgence of one class of people,” but on a government that “gives to bigotry no sanction.”
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Reza Shadmehr @rezashadmehr.bsky.social · 03/10/2025
Tenure-track faculty position in motor neuroscience at Penn State. psu.wd1.myworkdayjobs.com/PSU_Academic...
psu.wd1.myworkdayjobs.com
Open-Rank Faculty Position in Sensorimotor Control and Rehabilitation Neuroscience
APPLICATION INSTRUCTIONS: CURRENT PENN STATE EMPLOYEE (faculty, staff, technical service, or student), please login to Workday to complete the internal application process. Please do not apply here, a...
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Reza Shadmehr @rezashadmehr.bsky.social · 29/09/2025
I don't have much of a view from my office window, but this morning, the wind was brushing the vapor trails left by the rushing jets, leaving behind the froth of a cresting wave. If this was a superhero movie, there would be a surfer riding the waves in the sky.
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Reza Shadmehr @rezashadmehr.bsky.social · 23/09/2025
Since start of 2025, as compared to the same period in 2024, Johns Hopkins has received 40% fewer federal awards, a decline of ~50% in research funding, a reduction of $500 million. University wide, international graduate student enrollment is down by 8% since last year.
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Reza Shadmehr @rezashadmehr.bsky.social · 22/09/2025
The cerebellum receives a surprisingly rich amount of information regarding stimulus value via its climbing fibers. What role does this pathway play in learning to make better decisions? Haining Zhong will explain.
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Reza Shadmehr @rezashadmehr.bsky.social · 19/09/2025
Haining Zhong imaged climbing fibers during auditory discrimination, finding that they encode cue identities and perceptual choices. The responses were reshaped by reversal learning. The predictive nature of these signals suggests a role for climbing fibers in decision-making. Zoom link: email me.
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Reza Shadmehr @rezashadmehr.bsky.social · 04/09/2025
To understand cortico-cerebellar connectivity in humans, the usual approach is to exploit the correlations of functional brain imaging signals during rest. In this talk, Jorn Diedrichsen will present results suggesting that a better approach is to measure co-activation during specific tasks.
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Reza Shadmehr @rezashadmehr.bsky.social · 30/07/2025
At the Society for Neuroscience Conference this year, a scientific meeting to bring closer the neuroscientists who have cultural ties to the middle east. Please join us. www.middleeastneuro.com
middleeastneuro.com
Middle Eastern Systems Neuroscience Symposium
Join the Middle Eastern Systems Neuroscience Symposium on November 14, 2025, at UCSD Faculty Club, San Diego, in conjunction with the Society for Neuroscience (SfN) meeting. This event fosters scienti...
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Reza Shadmehr @rezashadmehr.bsky.social · 18/06/2025
In my drive this morning I thought how lucky I am to have a road and a working car in a city that is not being bombed. During lunch with my students I looked at their beautiful young faces and wished for them a better world.
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Reza Shadmehr @rezashadmehr.bsky.social · 13/06/2025
Shlomi Haar will present longitudinal studies of Parkinson's disease, focusing on anatomical and connectivity changes in the brain. Before diagnosis, there is a surprising increase in cerebellar white matter volume, followed by degeneration post-diagnosis.
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Reposted by Reza Shadmehr
The Transmitter @thetransmitter.bsky.social · 13/06/2025
For black-capped chickadees, looking out at a location activates the same place cells as actually being there, a study from Columbia University shows. By @martajhill.bsky.social #neuroskyence www.thetransmitter.org/hippocampus/...
thetransmitter.org
Gazing from afar activates place cells in chickadees
The results help explain how the hippocampus can recall information about a place without an animal physically revisiting it.
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Reza Shadmehr @rezashadmehr.bsky.social · 07/06/2025
Rui Costa introduces a computational framework in which cerebellar networks learn to guide cerebral cortex dynamics with task-outcome predictions.
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Reza Shadmehr @rezashadmehr.bsky.social · 02/06/2025
The cerebellum builds internal models of self motion, making it possible for us to read both the signs on the road, and our phones, while we walk. Jean Laurens will describe this computation. Seminars are open to all.
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Reza Shadmehr @rezashadmehr.bsky.social · 22/05/2025
Neuronal computation in the cerebellum via a vector calculus. Work of Mohammad Amin Fakharian, Alden Shoup, Paul Hage, and Hisham Elseweifi www.science.org/doi/10.1126/...
science.org
A vector calculus for neural computation in the cerebellum
Null space theory predicts that neurons generate spikes not only to produce behavior but also to prevent the undesirable effect of other neurons on behavior. In this work, we show that this competitiv...
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Reza Shadmehr @rezashadmehr.bsky.social · 22/05/2025
In people who suffer from essential tremor, excessive cerebellar oscillations give rise to involuntary, rhythmic movements. Ming-Kai Pan will present evidence from both mice and humans demonstrating that the cerebellum contributes to real-time motor control by encoding motor frequencies.
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Reza Shadmehr @rezashadmehr.bsky.social · 17/05/2025
To unlearn is hard, but necessary for recovery, because without it, some memories can bring us depression and anxiety. This process is called extinction learning. Enzo Nio and Dagmar Timmann explain the role of the cerebellum in learning to forget. Seminars are open to all (contact me).
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Reza Shadmehr @rezashadmehr.bsky.social · 11/05/2025
This little bluebird was born 2 weeks ago. Today he ventured to the opening of his birdhouse, felt the sun and the wind for the first time, stood there gripping the edge, deliberating for about 15 minutes, and then finally, leaped forward, opened his wings, and left home.
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Reza Shadmehr @rezashadmehr.bsky.social · 10/05/2025
Artificial neural networks use backprop, which attributes errors starting at the output layer, then works backwards. Cerebellum is also a multilayer network, but learning does not rely on backprop. How does the cerebellum guide learning in all of its layers? David Ehrlich explains.
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Reza Shadmehr @rezashadmehr.bsky.social · 02/05/2025
A group of neurons in the thalamus receive converging inputs from the basal ganglia and the cerebellum. Richard Roth explains the role of these neurons in motor control and motor learning. You can join live (email me), or watch the recordings: www.youtube.com/@shadmehrlab...
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Reza Shadmehr @rezashadmehr.bsky.social · 26/04/2025
Wiring of the brain during development is like a dance where neurons try different partners, then choose the perfect one. Fekrije Selimi explains how the parallel fibers and the climbing fibers find their Purkinje cell partners in the cerebellum.
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Reza Shadmehr @rezashadmehr.bsky.social · 17/04/2025
If the cerebellum is damaged, talking and singing become difficult, as if you have marbles in your mouth. Yet, the cerebellum is usually not included in the brain's vocal circuitry, particularly in songbirds. Lubica Kubikova explains how the cerebellum contributes to learning and performance of song
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