Harrison Ritz
@hritz.bsky.social
cybernetic cognitive control 🤖
computational cognitive neuroscience 🧠
postdoc princeton neuro 🍕
he/him 🇨🇦 harrisonritz.github.io
computational cognitive neuroscience 🧠
postdoc princeton neuro 🍕
he/him 🇨🇦 harrisonritz.github.io
Pinned
Harrison Ritz
@hritz.bsky.social
· Jul 27
We put out this preprint a couple months ago, but I really wanted to replicate our findings before we went to publication.
At first, what we found was very confusing!
But when we dug in, it revealed a fascinating neural strategy for how we switch between tasks
doi.org/10.1101/2024.09.29.615736
🧵
At first, what we found was very confusing!
But when we dug in, it revealed a fascinating neural strategy for how we switch between tasks
doi.org/10.1101/2024.09.29.615736
🧵
Reposted by Harrison Ritz
The Sensorimotor Superlab with @gribblelab.org and @andpru.bsky.social is a unique place to work and learn. We are now accepting MSc and PhD applications for Fall 2026. Join our awesome team at Western University... For application instructions see diedrichsenlab.org and gribblelab.org/join.html!
Diedrichsenlab
diedrichsenlab.org
November 24, 2025 at 10:50 PM
The Sensorimotor Superlab with @gribblelab.org and @andpru.bsky.social is a unique place to work and learn. We are now accepting MSc and PhD applications for Fall 2026. Join our awesome team at Western University... For application instructions see diedrichsenlab.org and gribblelab.org/join.html!
Reposted by Harrison Ritz
📍Excited to share that our paper was selected as a Spotlight at #NeurIPS2025!
arxiv.org/pdf/2410.03972
It started from a question I kept running into:
When do RNNs trained on the same task converge/diverge in their solutions?
🧵⬇️
arxiv.org/pdf/2410.03972
It started from a question I kept running into:
When do RNNs trained on the same task converge/diverge in their solutions?
🧵⬇️
November 24, 2025 at 4:43 PM
📍Excited to share that our paper was selected as a Spotlight at #NeurIPS2025!
arxiv.org/pdf/2410.03972
It started from a question I kept running into:
When do RNNs trained on the same task converge/diverge in their solutions?
🧵⬇️
arxiv.org/pdf/2410.03972
It started from a question I kept running into:
When do RNNs trained on the same task converge/diverge in their solutions?
🧵⬇️
Reposted by Harrison Ritz
Re: recent studies about neural coding being high-dimensional, and I thought I'd contribute our recent preprint: www.researchsquare.com/article/rs-1...
@eliezyer.bsky.social and I will do a full thread on this when the paper comes out, but his work shows it's (as usual) a little more complicated 🧵
@eliezyer.bsky.social and I will do a full thread on this when the paper comes out, but his work shows it's (as usual) a little more complicated 🧵
November 24, 2025 at 1:12 PM
Re: recent studies about neural coding being high-dimensional, and I thought I'd contribute our recent preprint: www.researchsquare.com/article/rs-1...
@eliezyer.bsky.social and I will do a full thread on this when the paper comes out, but his work shows it's (as usual) a little more complicated 🧵
@eliezyer.bsky.social and I will do a full thread on this when the paper comes out, but his work shows it's (as usual) a little more complicated 🧵
Reposted by Harrison Ritz
Just published my "Programming for Psychologists" course! 👩💻 github.com/Naubody/prog...
Designed for Psychology & Cognitive Neuroscience Master's students starting their programming journey at @vuamsterdam.bsky.social.
Feel free to share! Feedback welcome!
Designed for Psychology & Cognitive Neuroscience Master's students starting their programming journey at @vuamsterdam.bsky.social.
Feel free to share! Feedback welcome!
November 24, 2025 at 1:14 PM
Just published my "Programming for Psychologists" course! 👩💻 github.com/Naubody/prog...
Designed for Psychology & Cognitive Neuroscience Master's students starting their programming journey at @vuamsterdam.bsky.social.
Feel free to share! Feedback welcome!
Designed for Psychology & Cognitive Neuroscience Master's students starting their programming journey at @vuamsterdam.bsky.social.
Feel free to share! Feedback welcome!
Reposted by Harrison Ritz
New Preprint alert 🚨
“Inter-areal coupling for cognition through coincident oscillatory transients” together with
@ycaoneuro.bsky.social
@ktsetsos.bsky.social
@donnerlab.bsky.social &
Andreas Engel
#MEG #neuroscience #bioRxiv
www.biorxiv.org/content/10.1...
“Inter-areal coupling for cognition through coincident oscillatory transients” together with
@ycaoneuro.bsky.social
@ktsetsos.bsky.social
@donnerlab.bsky.social &
Andreas Engel
#MEG #neuroscience #bioRxiv
www.biorxiv.org/content/10.1...
Inter-areal coupling for cognition through coincident oscillatory transients
How do large-scale brain networks interact to enable cognition? Correlated oscillations, a mechanism for inter-areal interactions, can be expressed as phase coherence or amplitude co-fluctuations. Whi...
www.biorxiv.org
November 24, 2025 at 7:21 AM
New Preprint alert 🚨
“Inter-areal coupling for cognition through coincident oscillatory transients” together with
@ycaoneuro.bsky.social
@ktsetsos.bsky.social
@donnerlab.bsky.social &
Andreas Engel
#MEG #neuroscience #bioRxiv
www.biorxiv.org/content/10.1...
“Inter-areal coupling for cognition through coincident oscillatory transients” together with
@ycaoneuro.bsky.social
@ktsetsos.bsky.social
@donnerlab.bsky.social &
Andreas Engel
#MEG #neuroscience #bioRxiv
www.biorxiv.org/content/10.1...
Reposted by Harrison Ritz
Excited to share our NeurIPS spotlight paper that develops cell-type dynamical systems to understand the effects of neural perturbations, and roles of distinct cell classes in a neural circuit!
Joint work w/ @dikshagup.bsky.social , Carlos Brody, @jpillowtime.bsky.social .
(Details below)
Joint work w/ @dikshagup.bsky.social , Carlos Brody, @jpillowtime.bsky.social .
(Details below)
December 6, 2024 at 2:39 PM
Excited to share our NeurIPS spotlight paper that develops cell-type dynamical systems to understand the effects of neural perturbations, and roles of distinct cell classes in a neural circuit!
Joint work w/ @dikshagup.bsky.social , Carlos Brody, @jpillowtime.bsky.social .
(Details below)
Joint work w/ @dikshagup.bsky.social , Carlos Brody, @jpillowtime.bsky.social .
(Details below)
Just want to encourage Canadian depts to hire cog psych/neuro again 🫣
November 24, 2025 at 2:17 AM
Just want to encourage Canadian depts to hire cog psych/neuro again 🫣
Another nail in the coffin for PCA?
- doesn’t linearize, distorting similarity metrics
- is biased by temporal jitter across epochs
- may miss important dimensions for transient amplification
If you think there is a state space, use a state space model!
- doesn’t linearize, distorting similarity metrics
- is biased by temporal jitter across epochs
- may miss important dimensions for transient amplification
If you think there is a state space, use a state space model!
“Our findings challenge the conventional focus on low-dimensional coding subspaces as a sufficient framework for understanding neural computations, demonstrating that dimensions previously considered task-irrelevant and accounting for little variance can have a critical role in driving behavior.”
Neural dynamics outside task-coding dimensions drive decision trajectories through transient amplification
Most behaviors involve neural dynamics in high-dimensional activity spaces. A common approach is to extract dimensions that capture task-related variability, such as those separating stimuli or choice...
www.biorxiv.org
November 23, 2025 at 3:16 PM
Another nail in the coffin for PCA?
- doesn’t linearize, distorting similarity metrics
- is biased by temporal jitter across epochs
- may miss important dimensions for transient amplification
If you think there is a state space, use a state space model!
- doesn’t linearize, distorting similarity metrics
- is biased by temporal jitter across epochs
- may miss important dimensions for transient amplification
If you think there is a state space, use a state space model!
Reposted by Harrison Ritz
I wrote a little bit about the "missing heritability" question and several recent studies that have brought it to a close. A short 🧵
The missing heritability question is now (mostly) answered
Not with a bang but with a whimper
theinfinitesimal.substack.com
November 21, 2025 at 10:34 PM
I wrote a little bit about the "missing heritability" question and several recent studies that have brought it to a close. A short 🧵
Reposted by Harrison Ritz
𝗖𝗼𝗴𝗻𝗶𝘁𝗶𝘃𝗲 𝗳𝗹𝗲𝘅𝗶𝗯𝗶𝗹𝗶𝘁𝘆 𝗮𝗻𝗱 𝘀𝘁𝗮𝗯𝗶𝗹𝗶𝘁𝘆 𝘁𝗵𝗿𝗼𝘂𝗴𝗵 𝘁𝗵𝗲
𝗹𝗲𝗻𝘀 𝗼𝗳 𝗱𝘆𝗻𝗮𝗺𝗶𝗰𝗮𝗹 𝘀𝘆𝘀𝘁𝗲𝗺𝘀
"...trade-off between cognitive flexibility and stability inherent to dynamical system models of varying complexity."
by S Musslick and A Bizyaeva
#neuroskyence
doi.org/10.1016/j.co...
𝗹𝗲𝗻𝘀 𝗼𝗳 𝗱𝘆𝗻𝗮𝗺𝗶𝗰𝗮𝗹 𝘀𝘆𝘀𝘁𝗲𝗺𝘀
"...trade-off between cognitive flexibility and stability inherent to dynamical system models of varying complexity."
by S Musslick and A Bizyaeva
#neuroskyence
doi.org/10.1016/j.co...
November 22, 2025 at 6:43 PM
𝗖𝗼𝗴𝗻𝗶𝘁𝗶𝘃𝗲 𝗳𝗹𝗲𝘅𝗶𝗯𝗶𝗹𝗶𝘁𝘆 𝗮𝗻𝗱 𝘀𝘁𝗮𝗯𝗶𝗹𝗶𝘁𝘆 𝘁𝗵𝗿𝗼𝘂𝗴𝗵 𝘁𝗵𝗲
𝗹𝗲𝗻𝘀 𝗼𝗳 𝗱𝘆𝗻𝗮𝗺𝗶𝗰𝗮𝗹 𝘀𝘆𝘀𝘁𝗲𝗺𝘀
"...trade-off between cognitive flexibility and stability inherent to dynamical system models of varying complexity."
by S Musslick and A Bizyaeva
#neuroskyence
doi.org/10.1016/j.co...
𝗹𝗲𝗻𝘀 𝗼𝗳 𝗱𝘆𝗻𝗮𝗺𝗶𝗰𝗮𝗹 𝘀𝘆𝘀𝘁𝗲𝗺𝘀
"...trade-off between cognitive flexibility and stability inherent to dynamical system models of varying complexity."
by S Musslick and A Bizyaeva
#neuroskyence
doi.org/10.1016/j.co...
Reposted by Harrison Ritz
In case you aren't already aware of one of the nerdiest, nich-est online games: TeXnique, where the goal is to type LaTeX formulae as quickly as possible. texnique.xyz
It is "fun."
It is "fun."
November 21, 2025 at 9:14 PM
In case you aren't already aware of one of the nerdiest, nich-est online games: TeXnique, where the goal is to type LaTeX formulae as quickly as possible. texnique.xyz
It is "fun."
It is "fun."
Reposted by Harrison Ritz
short sighted at best....NHP research has been instrumental in the development of new treatments for human conditions (as well as other animals conditions/diseases as well).
EXCLUSIVE: CDC to end all monkey studies. Decision handed down by recent college grad and former DOGE employee who is now deputy chief of staff at the agency. Animals were being used in studies of HIV prevention. Some may be euthanized. My latest for @science.org
Exclusive: CDC to end all monkey research
Studies related to HIV and other infectious diseases will be phased out, sources say; fate of the agency's animals remains unclear
www.science.org
November 21, 2025 at 5:44 PM
short sighted at best....NHP research has been instrumental in the development of new treatments for human conditions (as well as other animals conditions/diseases as well).
Reposted by Harrison Ritz
Simulation-based inference has really become a commonly used tool for parameter inference across many fields and applications. We (finally...) got together to write a tutorial introduction and guide to (hopefully) help users get started and navigate the different methods and diagnostics!
Simulation-based inference (SBI) has transformed parameter inference across a wide range of domains. To help practitioners get started and make the most of these methods, we joined forces with researchers from many institutions and wrote a practical guide to SBI.
📄 Paper: arxiv.org/abs/2508.12939
📄 Paper: arxiv.org/abs/2508.12939
Simulation-Based Inference: A Practical Guide
A central challenge in many areas of science and engineering is to identify model parameters that are consistent with prior knowledge and empirical data. Bayesian inference offers a principled framewo...
arxiv.org
November 21, 2025 at 3:34 PM
Simulation-based inference has really become a commonly used tool for parameter inference across many fields and applications. We (finally...) got together to write a tutorial introduction and guide to (hopefully) help users get started and navigate the different methods and diagnostics!
Reposted by Harrison Ritz
New Special Issue at @imagingneurosci.bsky.social! direct.mit.edu/collection/7... 🧲
Special Issue on Optically Pumped Magnetometers | MIT Press
Optically Pumped Magnetometers (OPMs) have the potential to revolutionize magnetoencephalography (MEG) by enabling wearable, cryogen-free, and high-sensiti
direct.mit.edu
November 21, 2025 at 4:48 PM
New Special Issue at @imagingneurosci.bsky.social! direct.mit.edu/collection/7... 🧲
Reposted by Harrison Ritz
Ten Simple Rules for AI-Assisted Coding in Science arxiv.org/abs/2510.22254 - our latest, led by @ericwbridgeford.bsky.social
Ten Simple Rules for AI-Assisted Coding in Science
While AI coding tools have demonstrated potential to accelerate software development, their use in scientific computing raises critical questions about code quality and scientific validity. In this pa...
arxiv.org
October 28, 2025 at 1:12 PM
Ten Simple Rules for AI-Assisted Coding in Science arxiv.org/abs/2510.22254 - our latest, led by @ericwbridgeford.bsky.social
Does anyone know how to include non-linear predictors on both location and distributional parameters in brms? (eg on phi for beta regression)?
@dingdingpeng.the100.ci @rmcelreath.bsky.social
@tjmahr.com
@dingdingpeng.the100.ci @rmcelreath.bsky.social
@tjmahr.com
November 21, 2025 at 4:06 AM
Does anyone know how to include non-linear predictors on both location and distributional parameters in brms? (eg on phi for beta regression)?
@dingdingpeng.the100.ci @rmcelreath.bsky.social
@tjmahr.com
@dingdingpeng.the100.ci @rmcelreath.bsky.social
@tjmahr.com
This rules. Do your model recovery!
arxiv.org/abs/2510.23321
arxiv.org/abs/2510.23321
November 21, 2025 at 2:14 AM
This rules. Do your model recovery!
arxiv.org/abs/2510.23321
arxiv.org/abs/2510.23321
[citation needed] Most modern theories of executive functioning are not focused on decisions per se, but the regulation of processes like decision-making (eg setting the bound height, not tracking when the bound is crossed)
Otherwise looks like a cool review of distributed decision signals :)
Otherwise looks like a cool review of distributed decision signals :)
November 21, 2025 at 2:00 AM
[citation needed] Most modern theories of executive functioning are not focused on decisions per se, but the regulation of processes like decision-making (eg setting the bound height, not tracking when the bound is crossed)
Otherwise looks like a cool review of distributed decision signals :)
Otherwise looks like a cool review of distributed decision signals :)
Reposted by Harrison Ritz
Thanks, Adrian! I’m excited to be starting a lab at the University of Utah (theluolab.org)!
We’re recruiting at all levels.
If you’re excited about neural computation, large-scale multi-region recordings, and machine learning, let’s talk!
And yes, the mountains are as incredible as they say!
We’re recruiting at all levels.
If you’re excited about neural computation, large-scale multi-region recordings, and machine learning, let’s talk!
And yes, the mountains are as incredible as they say!
November 20, 2025 at 8:51 PM
Thanks, Adrian! I’m excited to be starting a lab at the University of Utah (theluolab.org)!
We’re recruiting at all levels.
If you’re excited about neural computation, large-scale multi-region recordings, and machine learning, let’s talk!
And yes, the mountains are as incredible as they say!
We’re recruiting at all levels.
If you’re excited about neural computation, large-scale multi-region recordings, and machine learning, let’s talk!
And yes, the mountains are as incredible as they say!
Reposted by Harrison Ritz
New pontification piece with @awestbrook.bsky.social and Jean Daunizeau, just out in TICS:
Why is cognitive effort experienced as costly?
(or why does it hurt to think)
never written a review paper before in my life, that was a new and unusual experience
Why is cognitive effort experienced as costly?
(or why does it hurt to think)
never written a review paper before in my life, that was a new and unusual experience
Why is cognitive effort experienced as costly?
A widespread observation is that people avoid mentally effortful courses of action,
and much recent work examining cognitive effort has explained subjective effort evaluation
– and, consequently, pref...
www.cell.com
November 19, 2025 at 2:48 PM
New pontification piece with @awestbrook.bsky.social and Jean Daunizeau, just out in TICS:
Why is cognitive effort experienced as costly?
(or why does it hurt to think)
never written a review paper before in my life, that was a new and unusual experience
Why is cognitive effort experienced as costly?
(or why does it hurt to think)
never written a review paper before in my life, that was a new and unusual experience
Reposted by Harrison Ritz
Excited to see our paper with @mwcole.bsky.social finally out in peer-reviewed form @natcomms.nature.com! We examine how the human brain learns new tasks and optimizes representations over practice…1/n
November 19, 2025 at 6:03 PM
Excited to see our paper with @mwcole.bsky.social finally out in peer-reviewed form @natcomms.nature.com! We examine how the human brain learns new tasks and optimizes representations over practice…1/n
Reposted by Harrison Ritz
I'm recruiting PhD students for my lab at Northwestern! I'm reviewing applications for the Department of Psychology for the Cognitive Affective Neuroscience and Clinical areas, due 12/1. 🧠
Come join the CATS Lab: nucatslab.com
Learn about our latest research: iamh.northwestern.edu/research/res...
Come join the CATS Lab: nucatslab.com
Learn about our latest research: iamh.northwestern.edu/research/res...
CATS Lab
Child & Adolescent Translational Science Lab at Northwestern University
nucatslab.com
October 29, 2025 at 6:39 PM
I'm recruiting PhD students for my lab at Northwestern! I'm reviewing applications for the Department of Psychology for the Cognitive Affective Neuroscience and Clinical areas, due 12/1. 🧠
Come join the CATS Lab: nucatslab.com
Learn about our latest research: iamh.northwestern.edu/research/res...
Come join the CATS Lab: nucatslab.com
Learn about our latest research: iamh.northwestern.edu/research/res...
Reposted by Harrison Ritz
New work by Emily Oby et al. in Nature Neuroscience demonstrates that neural population activity in motor cortex follows fixed dynamical constraints: monkeys could not volitionally reorder or reverse latent trajectories during BCI control.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Dynamical constraints on neural population activity - Nature Neuroscience
Oby, Degenhart, Grigsby and colleagues used a brain–computer interface to challenge monkeys to override their natural time courses of neural activity. They found the time courses to be highly robust, ...
www.nature.com
November 18, 2025 at 1:02 PM
New work by Emily Oby et al. in Nature Neuroscience demonstrates that neural population activity in motor cortex follows fixed dynamical constraints: monkeys could not volitionally reorder or reverse latent trajectories during BCI control.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Reposted by Harrison Ritz
My paper is out!
Computational modeling of error patterns during reward-based learning show evidence that habit learning (value free!) supplements working memory in 7 human data sets.
rdcu.be/eQjLN
Computational modeling of error patterns during reward-based learning show evidence that habit learning (value free!) supplements working memory in 7 human data sets.
rdcu.be/eQjLN
A habit and working memory model as an alternative account of human reward-based learning
Nature Human Behaviour - In this study, Collins proposes an alternative dual-process (working memory and habit) model of reinforcement learning in humans.
rdcu.be
November 17, 2025 at 5:18 PM
My paper is out!
Computational modeling of error patterns during reward-based learning show evidence that habit learning (value free!) supplements working memory in 7 human data sets.
rdcu.be/eQjLN
Computational modeling of error patterns during reward-based learning show evidence that habit learning (value free!) supplements working memory in 7 human data sets.
rdcu.be/eQjLN
Reposted by Harrison Ritz
I'm excited to co-chair an #SfN2025 nanosymposium with the esteemed @neuronush.bsky.social on intracranial and behavioral readouts of neuromodulation for psychiatric symptoms!
NANO048: "Human Intracranial Recordings: Cognitive and Clinical Science"
Wed. Nov. 19 from 8-10am (🙃)
Room 23A
NANO048: "Human Intracranial Recordings: Cognitive and Clinical Science"
Wed. Nov. 19 from 8-10am (🙃)
Room 23A
November 17, 2025 at 7:17 PM
I'm excited to co-chair an #SfN2025 nanosymposium with the esteemed @neuronush.bsky.social on intracranial and behavioral readouts of neuromodulation for psychiatric symptoms!
NANO048: "Human Intracranial Recordings: Cognitive and Clinical Science"
Wed. Nov. 19 from 8-10am (🙃)
Room 23A
NANO048: "Human Intracranial Recordings: Cognitive and Clinical Science"
Wed. Nov. 19 from 8-10am (🙃)
Room 23A