Dimitra Maoutsa's Avatar

Dimitra Maoutsa

@dimma

Theor/Comp Neuroscientist (postdoc) Prev @TU Munich Stochastic&nonlin. dynamics @TU Berlin&@MPIDS πŸ‘€ Learning dynamics, plasticity&geometry of representations https://dimitra-maoutsa.github.io https://dimitra-maoutsa.github.io/M-Dims-Blog

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03.07.2023
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Latest posts by Dimitra Maoutsa @dimma

Interested in dopaminergic learning, interaction of appetitive and aversive learning systems, & history-dependent modulation of learning? Come by my #cosyne2026 poster Thursday [1-096]: Reinforcement learning with distributed representations of prediction error and value.
#compneurosky #neuroskyence

11.03.2026 15:55 πŸ‘ 13 πŸ” 3 πŸ’¬ 0 πŸ“Œ 0

Very happy to share our review on Reinforcement Learning vs Statistical Learning, with @ambrafer.bsky.social and @predictivebrain.bsky.social:

www.sciencedirect.com/science/arti...

A nice summary:
www.sainsburywellcome.org/blog/two-eng...

11.03.2026 13:07 πŸ‘ 34 πŸ” 10 πŸ’¬ 0 πŸ“Œ 1

Is spatial navigation innate 🧠? Using #NeuroPixels we show that the #torus 🍩 underlying the #GridCell map exists already on day 10 in rats β€” before pups open eyes and ears and before they start upright walking. 🧡1:4
πŸ‘‡
www.biorxiv.org/content/10.6...

11.03.2026 10:34 πŸ‘ 77 πŸ” 21 πŸ’¬ 1 πŸ“Œ 5
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2/7 Using large-scale #Neuropixels recordings in rat pups (P8-P19), we recorded up to ~1000 simultaneous MEC-PaS units. We found toroidal manifolds in the medial entorhinal cortex (#MEC) as early as postnatal day 10 (P10), preceding eye/ear opening and active exploration🍩

11.03.2026 11:00 πŸ‘ 8 πŸ” 2 πŸ’¬ 1 πŸ“Œ 0

1/7 🧠 My journey into development begins with this work and question: how does the brain's spatial navigation system develop? We found that the neural networks for spatial navigation (tori and rings) are preconfigured and only later anchor gradually to the world with experience! 🧡

11.03.2026 11:00 πŸ‘ 97 πŸ” 44 πŸ’¬ 4 πŸ“Œ 13
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Come check out our poster at Cosyne 2026, on Thursday! Plasticity vs dynamics, RNN with online learning rule, inference based on structure and many other ideas!

BioRiv paper:
www.biorxiv.org/content/10.6...

11.03.2026 02:33 πŸ‘ 7 πŸ” 1 πŸ’¬ 0 πŸ“Œ 0
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Hippocampus a β€˜general-purpose statistical learning machine’ New cross-species findings may help settle a long-standing debate about whether the hippocampus is required for passively learning information.

Whether the hippocampus is involved in unrewarded learning has been a controversial question. A new preprint finds that it may be critical for passively learning information.

By @natmesanash.bsky.social

#neuroskyence

www.thetransmitter.org/memory/hippo...

10.03.2026 15:50 πŸ‘ 48 πŸ” 14 πŸ’¬ 0 πŸ“Œ 1
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Feedback control of random networks as a model of flexible motor cortical dynamics across tasks Kalidindi and Crevecoeur develop a computational framework linking feedback-controlled networks to limb dynamics. They demonstrate that optimal control of fixed network reproduces key motor cortical d...

Nice work, congratulations! In a recent model we found that similar neural dynamics may be due to similar task structure independent of network connectivity (supp. Figure). Could a simpler explanation be that all animals experienced essentially the same task structure?
www.cell.com/cell-reports...

10.03.2026 20:49 πŸ‘ 6 πŸ” 3 πŸ’¬ 1 πŸ“Œ 0
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To assess conserved neural computations, we tested the similarity of neural dynamics with Dynamical Similarity Analysis, an awesome technique for comparing the β€œrules” of two dynamical systems (arxiv.org/abs/2306.10168). Low dynamical distance, here, implies similar computations. 6/18

10.03.2026 17:42 πŸ‘ 6 πŸ” 2 πŸ’¬ 1 πŸ“Œ 0
Characteristics and dynamical signatures of recurrent cortical circuits during context-dependent processing Context profoundly shapes neural responses and behavior. During context-dependent sensory processing, recurrent connections shape the integration of feedforward sensory input and feed-back input from downstream brain regions. How do different cell types, interacting through spatially structured recurrent lateral connections, give rise to context-dependent processing and circuit stability, and what dynamical signatures reveal their individual roles? To answer these questions, we employ data-driven approaches to construct spatially extended stabilized supralinear network models that capture the responses of diverse cell types in the mouse primary visual cortex during context-dependent processing. Analysis of well-fitting models reveals that the dominant inhibitory cell type affecting excitatory neurons is not fixed but dynamically varies with stimulus and space. While PV-mediated stabilization is indispensable across all models and stimulus conditions, SST-mediated stabilization is also required, and likely in a stimulus-dependent manner. Interestingly, even when a specific inhibitory cell type is required for circuit stabilization, a uniform perturbation of it does not necessarily produce a paradoxical change in its mean activity. Instead, assessing cell-type-specific circuit stabilization requires patterned perturbations, where paradoxical effects manifest along specific activity modes. Finally, we show that recurrent connections and input-output nonlinearities are essential for integrating feedforward and feedback inputs to reproduce the observed spatial response profiles. Recurrent excitatory connections, in particular, are required to account for responses to small stimuli, where external inputs are relatively weak. Taken together, our work reveals the crucial role of ubiquitous biological components in context-dependent processing and delineates the characteristics and dynamical signatures of these circuits. ### Competing Interest Statement The authors have declared no competing interest. Gatsby Charitable Foundation, GAT3708 National Institutes of Health, https://ror.org/01cwqze88, 1RF1DA056397, U19NS107613, T32 EY013933 U.S. National Science Foundation, DGE-2036197 Simons Foundation, SCGB 543017 Agencia Estatal de InvestigaciΓ³n, PID2023-149174NB-I00

Interested in cell type diversity, the cortical operating regime, and how recurrent connections shape the integration of feedforward and feedback inputs during context-dependent processing? Come check out my poster [1-038] at #Cosyne2026.

Link: doi.org/10.64898/2026.02.06.704473

10.03.2026 14:15 πŸ‘ 11 πŸ” 2 πŸ’¬ 0 πŸ“Œ 0
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1-031, Poster session 1 (Thu, Mar. 12, 20:30): @maxschwabe.bsky.social (a Cosyne presenter awardee πŸŽ‰, a MASTER student) will present how decomposing neural dynamics to intrinsic and input-driven modes can tell us how naturalistic decision computations are realized in the RNNs.

09.03.2026 18:30 πŸ‘ 9 πŸ” 4 πŸ’¬ 1 πŸ“Œ 0

Check out our latest research drop! We show BLA dopamine signaling encodes the emotional weight of sensory transitions, but not the associative strength or value of stimuli. These signals dynamically rescale when the learning context changes: "this matters most!" www.biorxiv.org/content/10.1...

09.03.2026 15:06 πŸ‘ 58 πŸ” 25 πŸ’¬ 3 πŸ“Œ 0
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InputDSA: Demixing then comparing recurrent and externally driven dynamics in complex systems - Kempner Institute We explored how to measure the similarity between two complex systems when they are driven by external inputs, like biological neural circuits or reinforcement learning agents. Our novel method, calle...

NEW from the #KempnerInstitute: InputDSA, a tool to separate intrinsic dynamics from input-driven effectsβ€”enabling accurate, efficient comparisons of complex systems with external inputs.

Read the #DeeperLearning blog post by @annhuang42.bsky.social & @kanakarajanphd.bsky.social: bit.ly/4bkrvy9

09.03.2026 17:31 πŸ‘ 16 πŸ” 8 πŸ’¬ 0 πŸ“Œ 1
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Cerebellar climbing fibers impact experience-dependent plasticity in the mouse primary somatosensory cortex Optogenetic climbing fiber activation regulates experience-dependent plasticity in the primary somatosensory cortex of mice, suggesting a role of the olivo-cerebellum in instructive signaling across b...

Quite impressed with the results reported here, a cerebellar learning signal affects neocortex plasticity. In the context of credit assignment, this suggest a cross-system coordination of plasticity: elifesciences.org/articles/109...

09.03.2026 10:09 πŸ‘ 7 πŸ” 3 πŸ’¬ 0 πŸ“Œ 0
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Conflicting adaptations in an inhibitory feedback circuit Abstract figure legend We studied activity-dependent adaptation in the fruit fly Drosophila’s memory centre, the mushroom body. Here, excitatory Kenyon cells (KCs) receive feedback inhibition from th...

Check out our latest paper - In neural networks with inhibitory feedback, local homeostatic adaptation can conflict with adaptation at the network level doi.org/10.1113/JP29...

09.03.2026 08:34 πŸ‘ 17 πŸ” 4 πŸ’¬ 1 πŸ“Œ 1

Nepotism has made Iran weak.

by Jared Kushner and RFK Jr.

08.03.2026 22:56 πŸ‘ 1377 πŸ” 222 πŸ’¬ 18 πŸ“Œ 9
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Science thrives when diverse voices are heard.
This #InternationalWomensDay, we celebrate women everywhere - including women #neuroscientists who mentor, inspire & push the boundaries of discovery 🌟

Happy International Women’s Day from IBRO!

08.03.2026 08:00 πŸ‘ 7 πŸ” 3 πŸ’¬ 0 πŸ“Œ 0
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I’ll be presenting my work at #COSYNE2026. Stop by our poster to come learn about how the geometry of neural population activity shapes communication between brain areas during learned behavior πŸ¦β€β¬›πŸ§ πŸŽΆ

06.03.2026 23:17 πŸ‘ 12 πŸ” 2 πŸ’¬ 0 πŸ“Œ 0

Excited to give a talk at #Cosyne2026 about my PhD work!

We show that RNNs trained on visual search converge on brain-like solutions, producing primate-like behavior and neural representations. Happy to chat if you're at Cosyne!

πŸ“… March 15, 2026
πŸ“ Lisbon, Portugal
www.biorxiv.org/content/10.1...

06.03.2026 18:47 πŸ‘ 43 πŸ” 7 πŸ’¬ 1 πŸ“Œ 2
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Publisher demands $500 from impersonated author to retract paper Last year, we wrote about a Walsh Medical Media journal that refused to withdraw an author’s paper unless he paid a fee β€” even though he didn’t write or submit the article. For one reader, some details of that story were familiar. Laertis Ikonomou, an associate professor at the University of Buffalo in New York, … Continue reading Publisher demands $500 from impersonated author to retract paper

Lol. This is academic publishing taken to its logical end.

https://retractionwatch.com/2026/03/05/publisher-demands-500-from-impersonated-author-to-retract-paper/

07.03.2026 10:37 πŸ‘ 5 πŸ” 15 πŸ’¬ 0 πŸ“Œ 0
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Task learning increases information redundancy of neural responses in macaque visual cortex How does the brain optimize sensory information for decision-making in new tasks? One hypothesis suggests that learning reduces redundancy in neural representations to improve efficiency, whereas anot...

RIP redundancy reduction?

Beautiful work by Liu & colleagues showing that neural redundancy increases with learning, as predicted by a Bayesian model:
www.science.org/doi/10.1126/...

07.03.2026 11:08 πŸ‘ 68 πŸ” 25 πŸ’¬ 2 πŸ“Œ 1
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The most sensitive inputs to cutaneous representing regions of primary somatosensory cortex do not change with behavioral training - PubMed Learning a sensory detection task leads to an increased primary sensory cortex response to the detected stimulus, while learning a sensory discrimination task additionally leads to a decreased sensory cortex response to the distractor stimulus. Neural responses are scaled up, and down, in strength, …

Some people have written about how these two ideas may not be mutually exclusive.

pubmed.ncbi.nlm.nih.gov/26634900/

06.03.2026 14:48 πŸ‘ 3 πŸ” 1 πŸ’¬ 0 πŸ“Œ 0

As a result, we suspect the same neurons can exhibit different levels of stability to different stimuli based on network connectivity (as opposed to stimulus complexity/dimensionality). Just a hunch at this point, but seems plausible enough. More in this paper: www.nature.com/articles/s41...

05.03.2026 23:16 πŸ‘ 6 πŸ” 1 πŸ’¬ 1 πŸ“Œ 0

How are neural manifolds and single-neuron response properties related to circuit structure?

How degenerate are these relationships?

Theory and a plethora of examples can be found in the following paper, out today in Neuron 🌟

It was a privilege to co-supervise first author @lpezon.bsky.social!

06.03.2026 23:01 πŸ‘ 53 πŸ” 13 πŸ’¬ 1 πŸ“Œ 0
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3. We find that the circuit structure
– can impose symmetries on the network's low-dim. dynamics
– constrains the topology of the set of all single-neuron responses.
From the second point, we pinpoint topological features of neural activity relevant for comparing it with models.

06.03.2026 17:11 πŸ‘ 5 πŸ” 1 πŸ’¬ 1 πŸ“Œ 0
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Linking neural manifolds to circuit structure in recurrent networks Dimensionality reduction methods are widely used in neuroscience to investigate two complementary aspects of neural activity: the distribution of sing…

Excited to share our new paper to be published in Neuron!

With Valentin Schmutz @bio-emergent.bsky.social and Wulfram Gerstner @gerstnerlab.bsky.social, we explore how circuit structure in RNNs shapes network computation and single-neuron responses.
www.sciencedirect.com/science/arti...

06.03.2026 17:11 πŸ‘ 37 πŸ” 11 πŸ’¬ 1 πŸ“Œ 1
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Linking neural manifolds to circuit structure in recurrent networks Neural population activity can be described either by low-dimensional dynamics on neural manifolds or by single-neuron selectivities. Using a theoretical approach, Pezon et al. relate these two statistical descriptions to circuit structure in recurrent networks. Their results reveal both degeneracies and specific constraints in how circuit structure shapes neural activity.
06.03.2026 16:23 πŸ‘ 37 πŸ” 9 πŸ’¬ 0 πŸ“Œ 0

Orbitofrontal circuits for context-gated reward predictions https://www.biorxiv.org/content/10.64898/2026.03.05.709962v1

06.03.2026 15:16 πŸ‘ 8 πŸ” 5 πŸ’¬ 0 πŸ“Œ 1

Functional reorganization of motor cortex connectivity during learning https://www.biorxiv.org/content/10.64898/2026.03.03.709199v1

06.03.2026 04:18 πŸ‘ 3 πŸ” 1 πŸ’¬ 0 πŸ“Œ 0
View of How brains build higher order representations of uncertainty | Philosophy and the Mind Sciences Philosophy and the Mind Sciences (PhiMiSci) focuses on the interface between philosophy of mind, psychology, and cognitive neuroscience. PhiMiSci is a peer-reviewed, not-for-profit open-access journal...

it's out!

@hazimi.bsky.social and i explore how higher order representations of *one's own first-order representational uncertainty* -- not representations OF noisiness in the world -- can be studied, including how they are constructed in the first place.

philosophymindscience.org/index.php/ph...

06.03.2026 04:29 πŸ‘ 40 πŸ” 12 πŸ’¬ 0 πŸ“Œ 1