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M Ganesh Kumar

@mgkumar138.bsky.social
269 followers 220 following 34 posts

Neuro-AI Postdoc @ MPI Biological Cybernetics. Previously @Harvard, A*STAR & NUS. 🇸🇬

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Reposted by M Ganesh Kumar
Athena Akrami @athenaakrami.bsky.social · 16/02/2026
Thrilled to finally share this work! 🧠🔊 Using a new reinforcement-free task we show mice (like humans) extract abstract structure from sound (unsupervised) & dCA1 is causally required by building factorised, orthogonal subspaces of abstract rules. Led by Dammy Onih! www.biorxiv.org/content/10.6...
biorxiv.org
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Panos Roussos @panosroussos.bsky.social · 21/01/2026
Now out in @nature.com: Biological insights into schizophrenia from ancestrally diverse populations. @sinaibrain.bsky.social @sinaigenetics.bsky.social cs.bsky.social @timbigdeli.bsky.social #CDNeurogenomics #MountSinaiPsych #MillionVeteranProgram and many collaborators Read: rdcu.be/eZ7he
rdcu.be
Biological insights into schizophrenia from ancestrally diverse populations
Nature - Genome-wide association studies incorporating data for populations of African ancestry provide an expanded view of the genetic basis of schizophrenia, which has previously been studied...
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Reposted by M Ganesh Kumar
Nature @nature.com · 22/01/2026
Rates of ADHD have been rising quickly over the past few decades, for reasons that are not entirely clear — a mystery that underscores how much we still have to learn about the condition. go.nature.com/49TQWG5
go.nature.com
ADHD is on the rise, but why?
The more we learn, the less we seem to understand this condition.
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Mark Brandon @markbrandonlab.bsky.social · 14/01/2026
I’m very happy to share the latest from my lab published in @Nature Hippocampal neurons that initially encode reward shift their tuning over the course of days to precede or predict reward. Full text here: rdcu.be/eY5nh
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M Ganesh Kumar @mgkumar138.bsky.social · 19/01/2026
All theory is wrong until verified by data. Greatly indebted to @mhyaghoubi.bsky.social, @markbrandonlab.bsky.social, @douglasresearch.bsky.social for finding the hippocampus encoding reward prediction! Grateful to my advisor @cpehlevan.bsky.social, @kempnerinstitute.bsky.social. #RL #hippocampus
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Reposted by M Ganesh Kumar
PessoaBrain @pessoabrain.bsky.social · 07/09/2025
𝗕𝗿𝗮𝗶𝗻-𝗯𝗼𝗱𝘆 𝗽𝗵𝘆𝘀𝗶𝗼𝗹𝗼𝗴𝘆: 𝗟𝗼𝗰𝗮𝗹, 𝗿𝗲𝗳𝗹𝗲𝘅, 𝗮𝗻𝗱 𝗰𝗲𝗻𝘁𝗿𝗮𝗹 𝗰𝗼𝗺𝗺𝘂𝗻𝗶𝗰𝗮𝘁𝗶𝗼𝗻 Excellent review paper about reactive and anticipatory processes. #neuroskyence doi.org/10.1016/j.ce...
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M Ganesh Kumar @mgkumar138.bsky.social · 27/08/2025
I am extremely grateful to be awarded the National University of Singapore (NUS) Development Grant, and to be a Young NUS Fellow! Look forward to collaborating with the Yong Loo Lin School of Medicine on exciting projects. This is my first grant and hopefully many more to come! #NUS #NeuroAI
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Ann Kennedy @antihebbiann.bsky.social · 20/08/2025
I wrote a Comment on neurotheory, and now you can read it! Some thoughts on where neurotheory has and has not taken root within the neuroscience community, how it has shaped those subfields, and where we theorists might look next for fresh adventures. www.nature.com/articles/s41...
nature.com
Theoretical neuroscience has room to grow
Nature Reviews Neuroscience - The goal of theoretical neuroscience is to uncover principles of neural computation through careful design and interpretation of mathematical models. Here, I examine...
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Elliott Wimmer @elliottwimmer.bsky.social · 20/08/2025
🧵 New paper! We studied depression symptoms and goal-directed decisions under uncertainty @shiyiliang.bsky.social, with @evanrussek.bsky.social & @robbrutledge.bsky.social Surprisingly, we found that apathy–anhedonia was linked to enhanced goal-directed behavior. www.biorxiv.org/content/10.1...
biorxiv.org
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M Ganesh Kumar @mgkumar138.bsky.social · 19/08/2025
Not just for AI but these theories can improve our understanding of biological networks too!
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tal boger @talboger.bsky.social · 19/08/2025
On the left is a rabbit. On the right is an elephant. But guess what: They’re the *same image*, rotated 90°! In @currentbiology.bsky.social, @chazfirestone.bsky.social & I show how these images—known as “visual anagrams”—can help solve a longstanding problem in cognitive science. bit.ly/45BVnCZ
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Tomer Ullman @tomerullman.bsky.social · 19/08/2025
trying this with GPT-5 and charting new frontiers in gaslighting
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David G. Clark @david-g-clark.bsky.social · 19/08/2025
Wanted to share a new version (much cleaner!) of a preprint on how connectivity structure shapes collective dynamics in nonlinear RNNs. Neural circuits have highly non-iid connectivity (e.g., rapidly decaying singular values, structured singular-vector overlaps), unlike classical random RNN models.
arxiv.org
Connectivity structure and dynamics of nonlinear recurrent neural networks
Studies of the dynamics of nonlinear recurrent neural networks often assume independent and identically distributed couplings, but large-scale connectomics data indicate that biological neural circuit...
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M Ganesh Kumar @mgkumar138.bsky.social · 13/08/2025
3. We present TeDFA-δ, a bio. plaus. deep spiking RL model that leverages temporal integration and weak learning rules to outperform standard MLPs+BP for policy learning, highlighting the importance of neural dynamics over credit assignment for effective control: 2025.ccneuro.org/poster/?id=S...
2025.ccneuro.org
Poster Presentation
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M Ganesh Kumar @mgkumar138.bsky.social · 13/08/2025
2. We developed a bio. plaus. computational model of the dentate gyrus that shows how both impaired synaptic plasticity and increased neurogenesis—modulated by Cbln4-Neo1 complex—disrupt behavioral pattern separation: 2025.ccneuro.org/poster/?id=P...
2025.ccneuro.org
Poster Presentation
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M Ganesh Kumar @mgkumar138.bsky.social · 13/08/2025
1. We developed a RNN-based meta-RL framework that models schizophrenia-like decision-making deficits. We see a positive correlation between the number of dynamical attractor states and suboptimal behavior: 2025.ccneuro.org/poster/?id=4...
2025.ccneuro.org
Poster Presentation
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M Ganesh Kumar @mgkumar138.bsky.social · 13/08/2025
1 proceeding and 2 extended abstracts at Cognitive Computational Neuroscience (CCN) Conference 2025! Short summaries and links are in the thread. Look forward to the discussions! #CCN25
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Nature Reviews Neuroscience @natrevneuro.nature.com · 11/08/2025
The emergence of NeuroAI: bridging neuroscience and artificial intelligence — a Comment article by Sadra Sadeh & Claudia Clopath @sdrsd.bsky.social @clopathlab.bsky.social ‪ #neuroscience #neuroskyence www.nature.com/articles/s41...
nature.com
The emergence of NeuroAI: bridging neuroscience and artificial intelligence - Nature Reviews Neuroscience
Neuroscience has inspired artificial intelligence (AI) for decades but, in recent years, AI tools have begun to revolutionize neuroscience research. The emerging field of NeuroAI has the potential to ...
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Reposted by M Ganesh Kumar
Hyunwoo Gu @hyunwoogu.bsky.social · 29/07/2025
Excited to share that our paper is now out in Neuron @cp-neuron.bsky.social (dlvr.it/TM9zJ8). Our perception isn't a perfect mirror of the world. It's often biased by our expectations and beliefs. How do these biases unfold over time, and what shapes their trajectory? A summary thread. (1/13)
dlvr.it
Attractor dynamics of working memory explain a concurrent evolution of stimulus-specific and decision-consistent biases in visual estimation
People exhibit biases when perceiving features of the world, shaped by both external stimuli and prior decisions. By tracking behavioral, neural, and mechanistic markers of stimulus- and decision-rela...
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Reposted by M Ganesh Kumar
Andrew Lampinen @lampinen.bsky.social · 05/08/2025
In neuroscience, we often try to understand systems by analyzing their representations — using tools like regression or RSA. But are these analyses biased towards discovering a subset of what a system represents? If you're interested in this question, check out our new commentary! Thread:
What do representations tell us about a system? Image of a mouse with a scope showing a vector of activity patterns, and a neural network with a vector of unit activity patterns
Common analyses of neural representations: Encoding models (relating activity to task features) drawing of an arrow from a trace saying [on_____on____] to a neuron and spike train. Comparing models via neural predictivity: comparing two neural networks by their R^2 to mouse brain activity. RSA: assessing brain-brain or model-brain correspondence using representational dissimilarity matrices
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Sam Gershman @gershbrain.bsky.social · 04/08/2025
A landmark volume, The Handbook of Dopamine, is now online: www.sciencedirect.com/handbook/han... Big kudos to the editors, Stephanie Cragg and Mark Walton, for putting this together.
sciencedirect.com
Handbook of Behavioral Neuroscience | Volume 32: The Handbook of Dopamine | ScienceDirect.com by Elsevier
Read the latest chapters of Handbook of Behavioral Neuroscience at ScienceDirect.com, Elsevier’s leading platform of peer-reviewed scholarly literature
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David Sussillo @sussillodavid.bsky.social · 04/08/2025
Coming March 17, 2026! Just got my advance copy of Emergence — a memoir about growing up in group homes and somehow ending up in neuroscience and AI. It’s personal, it’s scientific, and it’s been a wild thing to write. Grateful and excited to share it soon.
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Dan Goodman @neural-reckoning.org · 11/07/2025
How can we test theories in neuroscience? Take a variable predicted to be important by the theory. It could fail to be observed because it's represented in some nonlinear, even distributed way. Or it could be observed but not be causal because the network is a reservoir. How can we deal with this?
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Grace Lindsay @neurograce.bsky.social · 23/07/2025
This summer my lab's journal club somewhat unintentionally ended up reading papers on a theme of "more naturalistic computational neuroscience". I figured I'd share the list of papers here 🧵:
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M Ganesh Kumar @mgkumar138.bsky.social · 12/07/2025
First #ICML2025 conference proceeding (icml.cc/virtual/2025...)! We (@frostedblakess.bsky.social, @jzv.bsky.social, @cpehlevan.bsky.social) developed a simple model to better understand state representation learning dynamics in both artificial and biological intelligent systems!
icml.cc
ICML Poster A Model of Place Field Reorganization During Reward MaximizationICML 2025
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M Ganesh Kumar @mgkumar138.bsky.social · 28/04/2025
State representation learning in the hippocampus?
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M Ganesh Kumar @mgkumar138.bsky.social · 23/04/2025
I'm heading back to Singapore for ICLR25! Hit me up for discussions or where to find good food! #neuroai #home
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M Ganesh Kumar @mgkumar138.bsky.social · 27/03/2025
Interestingly, we found no significant difference in under and over-updating behavior in Schizophrenia patient data (Nassar et al. 2021). Instead, analyzing the behavior using the delta area metric showed a significant difference, suggesting the utility of model-guided human-behavior data analysis.
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M Ganesh Kumar @mgkumar138.bsky.social · 27/03/2025
We used a fixed point finder algorithm and found that suboptimal agents (lower delta area value) exhibited smaller number of unstable fixed points compared to more optimal agents. The number of stable fixed points remained consistent across the delta area metric.
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M Ganesh Kumar @mgkumar138.bsky.social · 27/03/2025
Besides the (1) reward discount factor, we explored (2) prediction error scaling, (3) probability of disrupting RNN dynamics, (4) rollout buffer length. Each hyperparameter differently influenced the suboptimal decision making behavior, which we termed as delta area.
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M Ganesh Kumar @mgkumar138.bsky.social · 27/03/2025
Agents have to learn 2 solutions to predict changes in target location (change-point) and ignore outliers (oddballs). Decreasing the reward discount factor caused agents to under-update and over-update in each conditions respectively, replicating the maladaptive behavior seen in patients.
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M Ganesh Kumar @mgkumar138.bsky.social · 27/03/2025
New preprint! We trained an RNN using RL to solve a decision making task used to characterize suboptimal decision making by Schizophrenic patients. First project exploring comp psych models, thanks to @adam-manoogian.bsky.social @shawnrhoadsphd.bsky.social @bqian.bsky.social @cpehlevan.bsky.social
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M Ganesh Kumar @mgkumar138.bsky.social · 27/03/2025
I am speaking at COSYNE 2025. Please check out my talk if you're attending the event! #cosyne2025 #cosyne25
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M Ganesh Kumar @mgkumar138.bsky.social · 12/01/2025
I will be dropping by mid March, hope to catch you then!
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M Ganesh Kumar @mgkumar138.bsky.social · 10/01/2025
Thanks for setting this up, would love to be added!
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M Ganesh Kumar @mgkumar138.bsky.social · 10/01/2025
Congrats! Was nice meeting you in Singapore!
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M Ganesh Kumar @mgkumar138.bsky.social · 09/01/2025
Great review! Nice to see that schema is becoming popular again!
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M Ganesh Kumar @mgkumar138.bsky.social · 24/12/2024
Cool work!
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M Ganesh Kumar @mgkumar138.bsky.social · 24/12/2024
Interesting! Looking forward to the poster.
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M Ganesh Kumar @mgkumar138.bsky.social · 24/12/2024
Our Model on Place Field Reorganization with @frostedblakess.bsky.social, @jzv.bsky.social, @cpehlevan.bsky.social has been accepted at COSYNE! Look forward to sharing it with everyone! www.biorxiv.org/content/10.1...
biorxiv.org
A Model of Place Field Reorganization During Reward Maximization
When rodents learn to navigate in a novel environment, a high density of place fields emerges at reward locations, fields elongate against the trajectory, and individual fields change spatial selectiv...
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M Ganesh Kumar @mgkumar138.bsky.social · 18/12/2024
There is still a long way to go in the season. Let's see!
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M Ganesh Kumar @mgkumar138.bsky.social · 18/12/2024
Hopefully they remain 3rd in the table 😅 #ynwa
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M Ganesh Kumar @mgkumar138.bsky.social · 17/12/2024
Sorry for missing it out. Here it is! www.biorxiv.org/content/10.1...
biorxiv.org
A Model of Place Field Reorganization During Reward Maximization
When rodents learn to navigate in a novel environment, a high density of place fields emerges at reward locations, fields elongate against the trajectory, and individual fields change spatial selectiv...
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M Ganesh Kumar @mgkumar138.bsky.social · 17/12/2024
Link to the preprint: www.biorxiv.org/content/10.1...
biorxiv.org
A Model of Place Field Reorganization During Reward Maximization
When rodents learn to navigate in a novel environment, a high density of place fields emerges at reward locations, fields elongate against the trajectory, and individual fields change spatial selectiv...
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M Ganesh Kumar @mgkumar138.bsky.social · 17/12/2024
Thanks Erdem! Would love to be part of this community!
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M Ganesh Kumar @mgkumar138.bsky.social · 17/12/2024
We're currently validating some of these model predictions by analyzing neural datasets. If you are interested in exploring this model further or have relevant datasets, please DM me! #Hippocampus #RL #NeuroAI
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M Ganesh Kumar @mgkumar138.bsky.social · 17/12/2024
Ablation studies in 1D and 2D environments show that inducing these biological representations improve policy convergence and facilitate learning new targets.
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M Ganesh Kumar @mgkumar138.bsky.social · 17/12/2024
Noisy updates in place field parameters drive neural drift while compensatory plasticity mechanism maintains stable navigation behavior.
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M Ganesh Kumar @mgkumar138.bsky.social · 17/12/2024
A reward maximization objective also causes place fields to grow in size and shift backwards towards the start location, suggesting the development of a reward predictive representation.
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M Ganesh Kumar @mgkumar138.bsky.social · 17/12/2024
Place fields rapidly move closer to the target location to increase reward representation. The reorganization dynamics is modulated by the value of a location.
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