Reza Shadmehr
@rezashadmehr.bsky.social
Father, husband, scientist
At SFN in San Diego.
November 15, 2025 at 3:28 PM
At SFN in San Diego.
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...
doi.org/10.1073/pnas...
November 9, 2025 at 4:55 PM
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...
doi.org/10.1073/pnas...
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...
November 7, 2025 at 1:27 PM
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...
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...
They have twice as many neurons per brain mass than mammals, including primates.
www.pnas.org/doi/abs/10.1...
November 7, 2025 at 12:55 PM
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...
They have twice as many neurons per brain mass than mammals, including primates.
www.pnas.org/doi/abs/10.1...
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.”
November 4, 2025 at 12:17 PM
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.”
Tenure-track faculty position in motor neuroscience at Penn State.
psu.wd1.myworkdayjobs.com/PSU_Academic...
psu.wd1.myworkdayjobs.com/PSU_Academic...
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...
psu.wd1.myworkdayjobs.com
October 3, 2025 at 8:51 PM
Tenure-track faculty position in motor neuroscience at Penn State.
psu.wd1.myworkdayjobs.com/PSU_Academic...
psu.wd1.myworkdayjobs.com/PSU_Academic...
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.
September 29, 2025 at 11:50 AM
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.
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.
University wide, international graduate student enrollment is down by 8% since last year.
September 23, 2025 at 11:44 AM
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.
University wide, international graduate student enrollment is down by 8% since last year.
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.
September 22, 2025 at 11:23 AM
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.
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.
Zoom link: email me.
September 19, 2025 at 8:02 AM
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.
Zoom link: email me.
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.
In this talk, Jorn Diedrichsen will present results suggesting that a better approach is to measure co-activation during specific tasks.
September 4, 2025 at 1:39 PM
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.
In this talk, Jorn Diedrichsen will present results suggesting that a better approach is to measure co-activation during specific tasks.
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
www.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...
www.middleeastneuro.com
July 30, 2025 at 10:56 AM
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
www.middleeastneuro.com
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.
During lunch with my students I looked at their beautiful young faces and wished for them a better world.
June 18, 2025 at 5:18 PM
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.
During lunch with my students I looked at their beautiful young faces and wished for them a better world.
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.
June 13, 2025 at 12:38 PM
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.
Reposted by Reza Shadmehr
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/...
By @martajhill.bsky.social
#neuroskyence
www.thetransmitter.org/hippocampus/...
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.
www.thetransmitter.org
June 13, 2025 at 12:05 PM
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/...
By @martajhill.bsky.social
#neuroskyence
www.thetransmitter.org/hippocampus/...
Rui Costa introduces a computational framework in which cerebellar networks learn to guide cerebral cortex dynamics with task-outcome predictions.
June 7, 2025 at 12:07 PM
Rui Costa introduces a computational framework in which cerebellar networks learn to guide cerebral cortex dynamics with task-outcome predictions.
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.
Seminars are open to all.
June 2, 2025 at 11:56 AM
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.
Seminars are open to all.
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/...
Work of Mohammad Amin Fakharian, Alden Shoup, Paul Hage, and Hisham Elseweifi
www.science.org/doi/10.1126/...
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...
www.science.org
May 22, 2025 at 6:56 PM
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/...
Work of Mohammad Amin Fakharian, Alden Shoup, Paul Hage, and Hisham Elseweifi
www.science.org/doi/10.1126/...
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.
May 22, 2025 at 12:53 PM
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.
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).
Enzo Nio and Dagmar Timmann explain the role of the cerebellum in learning to forget.
Seminars are open to all (contact me).
May 17, 2025 at 12:01 PM
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).
Enzo Nio and Dagmar Timmann explain the role of the cerebellum in learning to forget.
Seminars are open to all (contact me).
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.
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.
May 11, 2025 at 6:52 PM
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.
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.
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.
How does the cerebellum guide learning in all of its layers? David Ehrlich explains.
May 10, 2025 at 5:47 PM
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.
How does the cerebellum guide learning in all of its layers? David Ehrlich explains.
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...
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...
May 2, 2025 at 11:53 AM
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...
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...
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.
Fekrije Selimi explains how the parallel fibers and the climbing fibers find their Purkinje cell partners in the cerebellum.
April 26, 2025 at 11:58 AM
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.
Fekrije Selimi explains how the parallel fibers and the climbing fibers find their Purkinje cell partners in the cerebellum.
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
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
April 17, 2025 at 12:46 PM
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
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