Stefano Palminteri
banner
stepalminteri.bsky.social
Stefano Palminteri
@stepalminteri.bsky.social
Computational cognitive scientist interested in learning and decision-making in human and machiches
Research director of the Human Reinforcement Learning team
Ecole Normale Supérieure (ENS)
Institut National de la Santé et Recherche Médicale (INSERM)
Pinned
New paper our in @pnas.org, lead by @isabellehoxha.bsky.social with Léo Sperber. We use evolutionary simulation to assess and compare the adaptive value of positivity bias and gradual perseveration in reinforcement learning. Follow the thread below (and Isabelle!) for more details!
Ever wondered why you keep going to that restaurant with stale fries? Is it because you went often in the past (perseveration) or because you remember past good experiences better (positivity bias)? Our study out in PNAS investigates the normative basis for these biases www.pnas.org/doi/10.1073/...
Evolving choice hysteresis in reinforcement learning: Comparing the adaptive value of positivity bias and gradual perseveration | PNAS
The tendency to repeat past choices more often than expected from the history of outcomes has been repeatedly empirically observed in reinforcement...
www.pnas.org
Also found in the old sci-fi stash recently purchased in Bologna
The plot’s crux is an illustration of the alignment problem (an all-powerful AI with wildly misaligned goals). Basically, the paperclip maximiser has gone rogue.
(but do not expect great writing and depth of reflection)
November 10, 2025 at 8:25 AM
Reposted by Stefano Palminteri
🚨 New preprint 🚨

Are reinforcement learning models complete accounts of decisions from experience if they ignore explicit memory?

In this new preprint, we show that people indeed form robust explicit memory representations that flexibly guide later decisions.

🔗 Preprint: doi.org/10.1101/2025...
October 29, 2025 at 8:24 AM
Reposted by Stefano Palminteri
🇪🇺 I am a bit late for this, but is important:

R.I.P. Sofia Corradi (1934 – 2025), the beautiful mind behind the ERASMUS project, one of the most successful and beloved EU programme.

It has changed the life (and mind) of ~15 million Europeans (including mine).

en.wikipedia.org/wiki/Sofia_C...
October 27, 2025 at 8:17 PM
🇪🇺 I am a bit late for this, but is important:

R.I.P. Sofia Corradi (1934 – 2025), the beautiful mind behind the ERASMUS project, one of the most successful and beloved EU programme.

It has changed the life (and mind) of ~15 million Europeans (including mine).

en.wikipedia.org/wiki/Sofia_C...
October 27, 2025 at 8:17 PM
Just read this old-school sci-fi gem I found in a vintage bookstore in Bologna, where a Practical Philosopher Corps is deployed across the galaxy to assess sentience and cognition in alien species.
I guess the dream job for @birchlse.bsky.social @petergs.bsky.social
October 26, 2025 at 4:22 PM
At a time when prominent thinkers like @anilseth.bsky.social Seth and Ned Block advocate a "strategic withdrawal" toward biologism in considering consciousness beyond the human case, our contrarian proposal is a methodological behaviourist computationalism.
www.linkedin.com/posts/stefan...
October 26, 2025 at 1:22 PM
Reposted by Stefano Palminteri
🚨 New publication: How to improve conceptual clarity in psychological science?

Thrilled to see this article with @ruimata.bsky.social out. We discuss how LLMs can be leveraged to map, clarify, and generate psychological measures and constructs.

Open access article: doi.org/10.1177/0963...
October 23, 2025 at 7:27 AM
Reposted by Stefano Palminteri
Very thought-provoking post by @prakhargodara.bsky.social. Is confirmation bias/positivity bias a statistical "ghost" of model specification? Specifically not including temporally decaying learning rates? The evidence suggests this is not the case and here is why (1/n)
Is confirmation bias a real cognitive flaw, or a statistical ghost created by our models? My new PNAS paper shows a startling result: fitting Q-learning models to behavior in bandit tasks detect a bias, even from the behavior of a perfectly rational Bayesian learner.
October 19, 2025 at 8:22 AM
Very thought-provoking post by @prakhargodara.bsky.social. Is confirmation bias/positivity bias a statistical "ghost" of model specification? Specifically not including temporally decaying learning rates? The evidence suggests this is not the case and here is why (1/n)
Is confirmation bias a real cognitive flaw, or a statistical ghost created by our models? My new PNAS paper shows a startling result: fitting Q-learning models to behavior in bandit tasks detect a bias, even from the behavior of a perfectly rational Bayesian learner.
October 19, 2025 at 8:22 AM
The associated online tool, however definitely nerdy, is addictive. Many kudos to @dirkwulff.bsky.social and co for setting this up and opening it to the community!
🚨 New preprint and online tool 🚨

Thrilled to share new work, mapping the 🗺️ landscape of behavioral reinforcement learning using an 🤖 LLM-powered bibliometric approach.

We built an online tool so you can explore the landscape yourself.

Online tool: mpib.berlin/vFVqU
Preprint: osf.io/6c2va_v1
October 19, 2025 at 7:50 AM
It was a real pleasure to be involved in the meta-scientific collaboration about the (historical, semantic and to some extent sociological) structure of the behavioral reinforcement learning field. Check @annaithoma.bsky.social thread below for more info!
🚨 New preprint: What does the research landscape of behavioral reinforcement learning look like 🌍?

We developed an LLM-powered bibliometric analysis to characterize article clusters, investigate their connections, and examine the distribution of topics across the landscape.

osf.io/6c2va_v1
OSF
osf.io
October 19, 2025 at 7:48 AM
If you want to know more about the reinforcement learning biases framework, I summarised it here:

www.researchgate.net/publication/...
October 14, 2025 at 7:38 AM
Reposted by Stefano Palminteri
Very cool study showing that "apparent" asymmetric update in reinforcement learning can emerge from Bayes optimal principles by Prakhar Godara in @pnas.org

www.pnas.org/doi/abs/10.1...
Apparent learning biases emerge from optimal inference: Insights from master equation analysis | PNAS
Recent studies [S. Palminteri, G. Lefebvre, E. J. Kilford, S. J. Blakemore, PLoS Comput. Biol. 13, e1005684 (2017); G. Lefebvre, M. Lebreton, F. Me...
www.pnas.org
October 13, 2025 at 12:03 PM
Very cool study showing that "apparent" asymmetric update in reinforcement learning can emerge from Bayes optimal principles by Prakhar Godara in @pnas.org

www.pnas.org/doi/abs/10.1...
Apparent learning biases emerge from optimal inference: Insights from master equation analysis | PNAS
Recent studies [S. Palminteri, G. Lefebvre, E. J. Kilford, S. J. Blakemore, PLoS Comput. Biol. 13, e1005684 (2017); G. Lefebvre, M. Lebreton, F. Me...
www.pnas.org
October 13, 2025 at 12:03 PM
Reposted by Stefano Palminteri
Thought experiments such as the Blockhead and Super-Super Spartans are often taken as “definitive” arguments against behavior-based inference of cognitive processes.
In our review -with @thecharleywu.bsky.social- we argue they may not be as definitive as originally thought.
October 9, 2025 at 12:34 PM
Reposted by Stefano Palminteri
I haven't given any news a while, I've been nose deep into this novel preprint with my excellent collaborators @stepalminteri.bsky.social, @urihertz.bsky.social and Bahador Bahrami: "Uncovering the semantics of teaching in
experiential learning with Large Language Models".
doi.org/10.31234/osf...
OSF
doi.org
October 11, 2025 at 5:32 AM
Thought experiments such as the Blockhead and Super-Super Spartans are often taken as “definitive” arguments against behavior-based inference of cognitive processes.
In our review -with @thecharleywu.bsky.social- we argue they may not be as definitive as originally thought.
October 9, 2025 at 12:34 PM
Reposted by Stefano Palminteri
New (revised) preprint with @thecharleywu.bsky.social
We rethink how to assess machine consciousness: not by code or circuitry, but by behavioral inference—as in cognitive science.
Extraordinary claims still need extraordinary evidence.
👉 osf.io/preprints/ps...
#AI #Consciousness #LLM
October 8, 2025 at 9:02 AM
New (revised) preprint with @thecharleywu.bsky.social
We rethink how to assess machine consciousness: not by code or circuitry, but by behavioral inference—as in cognitive science.
Extraordinary claims still need extraordinary evidence.
👉 osf.io/preprints/ps...
#AI #Consciousness #LLM
October 8, 2025 at 9:02 AM
Reposted by Stefano Palminteri
This book by @anilananth.bsky.social is great — perfect for those, like me, who have an intuitive and geometric grasp of math but unfortunately no formal training. Highly recommended!
October 1, 2025 at 3:47 PM
This book by @anilananth.bsky.social is great — perfect for those, like me, who have an intuitive and geometric grasp of math but unfortunately no formal training. Highly recommended!
October 1, 2025 at 3:47 PM
Reposted by Stefano Palminteri
Preprint alert! Navigating Inflationary and Deflationary Claims Concerning Large Language Models Avoiding Cognitive Biases.
Very fun and efficient collaboration with @giadapistilli.com
To help cognitively bounded humans balancing hype and dismall of LLMs capabilities
osf.io/preprints/ps...
OSF
osf.io
March 25, 2025 at 12:06 PM
Check out @bcdavidson.bsky.social's preprint (w/ @georgiaturner.bsky.social @orbenamy.bsky.social @livia-tomova.bsky.social and co.) about the (computational) consequences of social isolation in social media use during covid!
🚨 New Preprint 🚨

Prolonged Isolation is associated with an increased behavioural sensitivity to ‘Likes’ on social media.

🧵

Social media rewards are inherently social—but does posting change during social isolation, when in-person social rewards are limited?

It turns out, yes!
September 16, 2025 at 1:51 PM
Braitenberg's Vehicles arrived yesterday and I'm already halfway through it. An amazingly funny, clear, and lucid treatment of the question of attributing higher cognitive functions to artificial systems. Obviously very timely for current debates in AI
September 11, 2025 at 8:01 AM