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Arnav Raha

@pantamallion.bsky.social

300 followers 310 following 20 posts

Neuroscience PhD student at Columbia University | UC Berkeley alum | Studying RL mechanisms for vocal learning (+ fan of animals 🐋🦇🦜🦋🦑 🦎🦕)

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Arnav Raha @pantamallion.bsky.social · Mar 17

We know dopamine guides reinforcement learning in externally rewarded behaviors—think a mouse learning to press a lever for food or juice. But what about skills like speech or athletics, where there’s no explicit external reward, just an internal goal to match? 🧵 (1/7)

Arnav Raha @pantamallion.bsky.social · Mar 12

Excited to share our latest work! It’s been a great experience working on this (including building a whole new lab!) 😊

www.nature.com/articles/s41...

Natural behaviour is learned through dopamine-mediated reinforcement - Nature

Studies in zebra finches show that dopamine has a key role as a reinforcement signal in the trial-and-error process of learning that underlies complex natural behaviours.

www.nature.com

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Rebecca R Helm @rebeccarhelm.bsky.social · 13d

I get that the news cycle is packed right now, but I just heard from a colleague at the Smithsonian that this is fully a GIANT SQUID BEING EATEN BY A SPERM WHALE and it’s possibly the first ever confirmed video according to a friend at NOAA

10 YEAR OLD ME IS LOSING HER MIND (a thread 🧵)

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Grant Sanderson @3blue1brown.com · Sep 7

New video about a piece by the modern artist Sol LeWitt, and the group theory behind it.

youtu.be/_BrFKp-U8GI

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Eugene Vinitsky 🍒 @eugenevinitsky.bsky.social · Sep 3

Reminded again of Kevin Murphy's excellent RL overview: arxiv.org/abs/2412.05265
A lot of the stuff covered here really is at the cutting edge and not compiled so nicely anywhere else

Reinforcement Learning: An Overview

This manuscript gives a big-picture, up-to-date overview of the field of (deep) reinforcement learning and sequential decision making, covering value-based methods, policy-based methods, model-based m...

arxiv.org

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Arnav Raha @pantamallion.bsky.social · Aug 29

woah are the japanese 鳥類 (chorui?) & bangla চড়ুই (chorui) somehow related or is it (I presume) just a fun coincidence

Reposted by Arnav Raha

David G. Clark @david-g-clark.bsky.social · Aug 25

(1/26) Excited to share a new preprint led by grad student Albert Wakhloo, with me and Larry Abbott: "Associative synaptic plasticity creates dynamic persistent activity."
www.biorxiv.org/content/10.1...

Associative synaptic plasticity creates dynamic persistent activity

In biological neural circuits, the dynamics of neurons and synapses are tightly coupled. We study the consequences of this coupling and show that it enables a novel form of working memory. In recurren...

www.biorxiv.org

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Arnav Raha @pantamallion.bsky.social · Aug 23

It was a great experience mentoring this cohort for the past 8 months—excited to see what they get up to next!

Columbia University's Zuckerman Institute @zuckermanbrain.bsky.social · Aug 23

Last week we proudly celebrated the graduating BRAINYAC class with a poster session highlighting the students’ research! BRAINYAC partners 10th & 11th graders from schools in Upper Manhattan & the Bronx with @columbiauniversity.bsky.social neuroscientists.

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Ralph Emilio Peterson @ralphpeterson.bsky.social · Jul 25

New preprint!  

tl;dr — We ran around late at night to record wild rats in NYC and figured out how to quantify their behavior and environment. 🧵

w/ Dima Batenkov, @zamakany.bsky.social, Emily Mackevicius

www.biorxiv.org/content/10.1...

Computational Urban Ecology of New York City Rats

Urban rats are highly adaptable, thriving in the dynamic and often inhospitable conditions of modern cities. Despite substantial mitigation efforts, they remain an enduring presence in urban environme...

www.biorxiv.org

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Asher Hellbein @asherelbein.bsky.social · Jul 23

Proud to make my National Geographic debut with this incredible discovery! Meet Mirasaura, an extremely weird little guy with independently-evolved "feathers" that solves a longstanding Triassic mystery and makes one of the period's oddest families even stranger.

(Now with a fixed link!)

Is it a bird? A monkey? No, it's a 'miraculous' new prehistoric reptile

Mirasaura grauvogeli had a featherlike crest and a tail like a monkey. “It's been a long time since I've been so blown away by a new fossil discovery.”

www.nationalgeographic.com

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Gabriel Ugueto @serpenillus.bsky.social · Jul 2

Everyone, please meet Sphenodraco! A newly described sphenodontian (a tuatara relative) from the Late Jurassic of Europe published TODAY!

#paleoart #reptiles #sciart #art

An illustration showing Sphenodraco perched on a tree trunk while a group of Rhamphorhynchus fly in the background

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Ishmail Abdus-Saboor @ishmailsaboor.bsky.social · Jul 2

I am happy to share that I’ve been awarded tenure here at Columbia University. Alhamdulillah. I thank my wife, parents, mentors, colleagues, friends, and family. I thank my lab members, present and past, for entrusting their careers in my hands and making this a thrilling journey.

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International Society for Neuroethology @neuroethology.org · Jul 2

We are looking for early carrer researchers who want to share their fascination for Neuroethology by introducing their work.

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Ken Miller @kenmiller.bsky.social · Jun 25

Mamdani winning and it's not even close! Rejection of Machiavellian power-mad sex-harasser w full support of Dem establishment & $20M in PAC $$, in favor of a young fresh, guy really committed to ordinary people with a huge grassroots volunteer effort. Huge grassroots victory!

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Timothy Burke @bubbaprog.xyz · Jun 25

"GOOD FUCKING RIDDANCE"

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Kashana @kashana.blacksky.app · Jun 25

Turns out there was a more exciting message than better things aren’t possible

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gamera obscura @ohrobin.bsky.social · Jun 25

When we run leftist candidates, those candidates win. Because leftist values ARE the values the people believe in. Respond to. Show up for.

Whatever the donor class may tell you, and however hard they may fight us, remember that. These are the policies that WIN.

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Hannah Payne @hannahpayne.bsky.social · Jun 11

My latest Aronov lab paper is now published @Nature!

When a chickadee looks at a distant location, the same place cells activate as if it were actually there 👁️

The hippocampus encodes where the bird is looking, AND what it expects to see next -- enabling spatial reasoning from afar

bit.ly/3HvWSum

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Angela Stoeger @angelastoeger.bsky.social · May 19

Check out my review of Is Anyone Listening?: What Animals Are Saying to Each Other and to Us by marine biologist and dolphin researcher Denise L. Herzing, published in Current Biology:
www.cell.com/curre.../abs...

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George Ordiway @georgeordiway.bsky.social · Jun 13

youtube.com/shorts/v-JNF...

Incredible, not just a "how did dinosaurs go from teeth to beaks" but also how young and old animals had completely different diets.

Chew on This! Or...Maybe Not...

YouTube video by Your Dinosaurs Are Wrong

youtube.com

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Rosemary Mosco @rosemarymosco.com · May 22

Found a baby songbird? Here's a newly updated chart!

A chart that explains what to do If You Find A Baby Songbird Out Of The Nest. Is it hurt or did a cat get it? (Cat bites & scratches cause deadly infections.) or, Has a person kept it for over a day, given it food or water, or gotten it wet? If yes, Contact a licensed wildlife rehabilitator
or wildlife care center near you. An online search can help. If no, what does it look like? Eyes not yet open. You have a hatchling. It's very young. Eyes open; feathers few & may be in tube-like sheaths. You have a nestling. Feathered; awkwardly hops or flutters; tail & wings short. You have a fledgling. Many sharp teeth; large claw on second toe. You have a velociraptor. If a hatchling or nestling, can you see the nest? If yes, Return it to its nest. The parents won’t care if they can smell you. If no, Make a nest from a basket & dried grass. Wire it to a tree. (Note: A few species, like Juncos, need a nest on the ground.) If a fledgling, is it in immediate danger? If yes, carefully move it to a safer spot nearby. If no, DO NOT INTERVENE! Though the bird looks awkward, it’s in a natural stage & the parents are still feeding it. If a velociraptor, has it seen you? If yes, back away slowly. Do not show fear. If no, run. Watch for others that may attack from the sides. FYI: Some babies (eg. swifts, most woodpeckers) only sit on the ground if in trouble. When in doubt, keep watch & contact a wildlife rehabilitator if needed!

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Javier Lazaro - illustration @lazaroillustration.bsky.social · May 7

May will be the month of the hyena. Here you have your daily dose.
#SciArt #hyaena #wildlife #art #mammals @mpi-animalbehav.bsky.social

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Caxela @caxela.bsky.social · May 3

Koreaceratops

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Max Kozlov @maxkozlov.bsky.social · Apr 10

NEW: Entire scientific fields have been wiped out by the nearly 800 grants cancelled at NIH, finds a @nature.com analysis of the unprecedented cuts.

About half of all 2024 NIH projects related to LGBT+ health or vaccine hesitancy — gone.

See the other topics and US states hardest hit here:

How Trump 2.0 is slashing NIH-backed research — in charts

Nature analyses which fields of science and US states are being hit hardest by grant terminations.

www.nature.com

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Satpreet (Sat) Singh @satpreetsingh.bsky.social · Apr 7

Kristopher Jensen (@kristorpjensen.bsky.social): Recurrent network models of planning in prefrontal cortex
www.youtube.com/watch?v=baY8...

Kristopher Jensen: Recurrent network models of planning in prefrontal cortex

YouTube video by NeuroAgents Workshop

www.youtube.com

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Satpreet (Sat) Singh @satpreetsingh.bsky.social · Apr 7

📽️Recordings from our
@cosynemeeting.bsky.social
#COSYNE2025 workshop on “Agent-Based Models in Neuroscience: Complex Planning, Embodiment, and Beyond" are now online: neuro-agent-models.github.io
🧠🤖

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animal prattle @animal-prattle.bsky.social · Apr 8

🔥 Spicy take alert!

"Vocal Learning Versus Speech Evolution: Untangling a False Equivalence", new from Adriano Lameira
onlinelibrary.wiley.com/doi/10.1002/...

#prattle 💬
#bioacoustics

Screenshot of abstract from linked paper, with a sentence highlighted

A head‐start of millions of years of vocal evolution didn't produce linguistic elephants, bats, or birds, suggesting that hominids' humble vocal beginnings were determinant for verbal evolution.

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