Arnav Raha
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arnavraha.bsky.social
Arnav Raha
@arnavraha.bsky.social
Neuroscience PhD candidate at Columbia University | UC Berkeley alum | Studying RL mechanisms for vocal learning (+ fan of animals 🐋🦇🦜🦋🦑 🦎🦕)
Pinned
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)
Reposted by Arnav Raha
My first PhD paper is published! 🎉 We compared how wild bonobo and chimpanzee infants (0-5.5y) become independent from their mothers. Here is the open-access link: onlinelibrary.wiley.com/doi/epdf/10....

🧵(1/5)
Great Ape Childhoods: Social and Spatial Pathways to Independence in Bonobo and Chimpanzee Infants
onlinelibrary.wiley.com
December 16, 2025 at 12:19 PM
Reposted by Arnav Raha
Cross-species consensus atlas of the primate basal ganglia https://www.biorxiv.org/content/10.64898/2025.12.15.694496v1
December 16, 2025 at 2:15 PM
Reposted by Arnav Raha
A quick tip on insect wings
#sciart #art #insects
December 16, 2025 at 2:46 PM
Reposted by Arnav Raha
what's in a meow?? 🐈

New from @berlinbatlab.bsky.social!

1. "we examined meows and purrs to establish how individual identity is encoded"
2. stronger individual signature in purrs than in meows
3. domestic cat meows more variable than those of wild felids

#bioacoustics
#prattle 💬
#neuroskyence
December 15, 2025 at 3:45 PM
Reposted by Arnav Raha
1/X Excited to present this preprint on multi-tasking, with
@david-g-clark.bsky.social and Ashok Litwin-Kumar! Timely too, as “low-D manifold” has been trending again. (If you read thru the end, we escape Flatland and return to the glorious high-D world we deserve.) www.biorxiv.org/content/10.6...
A theory of multi-task computation and task selection
Neural activity during the performance of a stereotyped behavioral task is often described as low-dimensional, occupying only a limited region in the space of all firing-rate patterns. This region has...
www.biorxiv.org
December 15, 2025 at 7:41 PM
Reposted by Arnav Raha
An American Tree Sparrow (left) and a Dark-eyed Junco (right) having a discussion about who gets to look for food in this patch of snow.
December 14, 2025 at 11:52 PM
Reposted by Arnav Raha
Colossal Biosciences: "we have mammoths at home"

The mammoth at home:
Hey mammalogists, what kind of elephant is this?
December 7, 2025 at 8:07 PM
Reposted by Arnav Raha
PLEASE SHARE

🚨🚨 6-month RA position available at the Univ. of St Andrews to work with Sue Healy (@cogwild.bsky.social), Simone Meddle (@simonemeddle.bsky.social) and I on the behavioural neuroendocrinology of early reproduction in zebra finches.

tinyurl.com/577cx9tj

Deadline: 03/12/2025
⬇️
November 19, 2025 at 6:23 PM
Reposted by Arnav Raha
Seasonal vs opportunistic breeders, a seasonal morphological and endocrine comparative study of the gonadal cycle in birds | www.sciencedirect.co... | General and Comparative Endocrinology | #ornithology 🪶
Seasonal vs opportunistic breeders, a seasonal morphological and endocrine comparative study of the gonadal cycle in birds
Avian reproduction is usually seasonal and strongly influenced by environmental factors, primarily photoperiod, which is mainly perceived by deep brai…
www.sciencedirect.com
November 11, 2025 at 10:25 AM
Reposted by Arnav Raha
Now in PRX: Theory linking connectivity structure to collective activity in nonlinear RNNs!
For neuro fans: conn. structure can be invisible in single neurons but shape pop. activity
For low-rank RNN fans: a theory of rank=O(N)
For physics fans: fluctuations around DMFT saddle⇒dimension of activity
Connectivity Structure and Dynamics of Nonlinear Recurrent Neural Networks
The structure of brain connectivity predicts collective neural activity, with a small number of connectivity features determining activity dimensionality, linking circuit architecture to network-level...
journals.aps.org
November 3, 2025 at 9:47 PM
Reposted by Arnav Raha
not to be confused with quesadilla
October 27, 2025 at 7:21 PM
Reposted by Arnav Raha
October 23, 2025 at 5:35 PM
Come learn about naked mole rat brains!
NYC 🗣️

Please join/spread the word of this free neuroscience event!

Our LNS team puts on monthly events that are open to the public that are intended to give our NYC community insight on what happens in a Columbia lab. A tour of the lab space is provided! Please share! 🧠🌙
October 23, 2025 at 12:17 AM
Reposted by Arnav Raha
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 🧵)
September 24, 2025 at 8:30 PM
Reposted by Arnav Raha
New video about a piece by the modern artist Sol LeWitt, and the group theory behind it.

youtu.be/_BrFKp-U8GI
September 7, 2025 at 12:39 PM
Reposted by Arnav Raha
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
September 3, 2025 at 1:47 AM
woah are the japanese 鳥類 (chorui?) & bangla চড়ুই (chorui) somehow related or is it (I presume) just a fun coincidence
August 29, 2025 at 11:58 PM
Reposted by Arnav Raha
(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
August 25, 2025 at 5:17 PM
It was a great experience mentoring this cohort for the past 8 months—excited to see what they get up to next!
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.
August 23, 2025 at 9:30 PM
Reposted by Arnav Raha
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
July 25, 2025 at 3:57 PM
Reposted by Arnav Raha
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
July 23, 2025 at 6:30 PM
Reposted by Arnav Raha
Everyone, please meet Sphenodraco! A newly described sphenodontian (a tuatara relative) from the Late Jurassic of Europe published TODAY!

#paleoart #reptiles #sciart #art
July 2, 2025 at 1:34 PM
Reposted by Arnav Raha
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.
July 2, 2025 at 1:43 PM
Reposted by Arnav Raha
We are looking for early carrer researchers who want to share their fascination for Neuroethology by introducing their work.
July 2, 2025 at 2:29 PM