iiinova — where your digital self keeps evolving

Reposted by Dr. Alexandra Witt

Kenji Itao @kenjiitao.bsky.social · 02/03/2026

From Apr 1, 2026, I’ll launch my own lab at Tohoku University as an Assistant Professor! I’m happy to host applicants for the JSPS International Postdoc Fellowships. If you’re interested in mathematical models of human history, feel free to DM me!

jsps.go.jp

About the Program (Standard)｜Postdoctoral Fellowships for Research in Japan｜Postdoctoral Fellowships for Research in Japan

Official Website of Japan Society for the Promotion of Science (JSPS)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 28/01/2026

Happy to announce I started a postdoc with @watarutoyokawa.bsky.social at RIKEN-CBS! 🎉 I'm absolutely thrilled to be here (and not just because it's easy to find great waterfalls) For this position, I'm broadening my research to include more interactive and naturalistic social learning settings 🧠

Me at the RIKEN Center for Brain Science, my new place of work!

Me at Haha no Shirataki, a gorgeous waterfall near Mt. Fuji. It's pictured half-frozen, making it outstandingly cool

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Reposted by Dr. Alexandra Witt

Pantelis P. Analytis @pantelispa.bsky.social · 01/12/2025

I am hiring a postdoc for a DFF-funded project on social influence, and the decision processes that fuel rich-get-richer dynamics in the online/offline world. The position is for up to a year, competitive Danish salary, remote work possible. Interested or know somebody? DM me or share!

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Dr. Alexandra Witt @alexthewitty.bsky.social · 25/11/2025

Other highlights of the day included the cockiest slide I’ve made in my life, and my hat being almost the right size

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Dr. Alexandra Witt @alexthewitty.bsky.social · 25/11/2025

Over the moon to announce that, as of last Friday, I’m officially #PhDone! I’d like to thank everyone who supported me along the way, including, but not limited to, my amazing supervisor @thecharleywu.bsky.social, and all members (past or present) of the HMC lab and the @velezcolab.bsky.social 🎓

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Reposted by Dr. Alexandra Witt

Bonan Zhao (赵博囡) @bonan.bsky.social · 17/08/2025

My Lab at the University of Edinburgh🇬🇧 has funded PhD positions for this cycle! We study the computational principles of how people learn, reason, and communicate. It's a new lab, and you will be playing a big role in shaping its culture and foundations. Spread the words!

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Reposted by Dr. Alexandra Witt

SFB 1528 - Cognition of Interaction @sfb1528.bsky.social · 07/08/2025

Don't miss it! Submit your abstract for our Satellite Symposium on Computational Neuroscience to celebrate 20 years Bernstein Center for Computational Neuroscience Göttingen! Deadline for your abstracts is August 17! Participation is free! Join us in Göttingen on Oct 15!

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Dr. Alexandra Witt @alexthewitty.bsky.social · 02/08/2025

Happening today after lunch! Stop by W-213 (conveniently placed at the very entrance of the salon, near fresh air!) to hear about positivity biases across individual and social learning #cogsci2025

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Reposted by Dr. Alexandra Witt

Vélez Lab at UCSD @velezcolab.bsky.social · 29/07/2025

The CoLab is headed to #CogSci2025!! 🥳 Here's where to find us!

A lineup showing upcoming talks and posters for the CoLab at CogSci 2025.

Wednesday
Natalia Vélez: Understanding structural diversity in human collaboration
Metareasoning Workshop, Pacific H, 10:30-11:10am

Thursday
Huang Ham: Collaborative encoding of visual working memory
P1-H-244

Friday
Bonan Zhao (new PI!): Discovering hidden laws in innovation by recombination
P2-Z-231

Elizabeth Mieczkowski: A normative account of specialization: How task and environment shape role differentiation in collaboration
P2-M-133

Bella Fascendini: Are two-year-olds intrinsically motivated to explore their own competence?
Learning & Development 2, Salon 6, 1-2:30pm

Saturday
Renée Creppy (first-timer!): Children’s expectations of dominant and prestigious leaders
P3-C-40

Natalia Vélez: Thinking in teams
Invited Symposium: New Theoretical Directions in Cognitive Science
Salon 7, 2:15-3:45pm

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Reposted by Dr. Alexandra Witt

Björn Lindström @bjornlindstrom.bsky.social · 23/07/2025

Thrilled that our paper on the mechanisms underlying social learning strategies is out! First big paper from my @erc.europa.eu & @kawresearch.bsky.social funded group. More to come! I'm currently looking to recruit two post docs, get in touch if you find this line of research interesting.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 24/07/2025

This was so fun! Thanks to everyone for coming, presenting, and exchanging ideas! :)

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Reposted by Dr. Alexandra Witt

Junyi Chu @junyi.bsky.social · 06/06/2025

Delighted to announce our CogSci '25 workshop at the interface between cognitive science and design 🧠🖌️! We're calling it: 🏺Minds in the Making🏺 🔗 minds-making.github.io June – July 2024, free & open to the public (all career stages, all disciplines)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 26/05/2025

Taken together, we find that learning rate biases are more flexible than expected, and especially flexible (and adaptive) in social learning settings. Thanks for reading this far, and since you already put in all this effort, consider giving the full paper a read! :)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 26/05/2025

We also find that bias isn't as stable as we expected: while there is still a significant positivity bias in individual + rich, we also find a high proportion of unbiased learners. Participants changed their bias between conditions, rather than being consistently positivity-(or negativity-) biased.

Bar chart showing the proportion of participants best fit by an unbiased learning model vs. positivity- and negativity-biased participants (determined by the difference in bias in participants best fit by a biased learning model). Proportions vary across conditions, with the highest proportion of positivity bias in social + poor, followed by individual + poor. Individual + rich has the highest proportion of unbiased participants (but no negativity biased participants), while social + rich has the highest proportion of negativity-biased participants.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 26/05/2025

Participants were significantly positivity-biased in both individual conditions (matching previous findings), but they were only positivity biased in poor environments for social learning, while we found no significant bias in rich environments (where positivity bias is maladaptive).

Beeswarm plots comparing positive and negative learning rates across conditions. The positive learning rate is significantly higher than the negative learning rate in poor and rich environments for individual learning, and in poor environments for social learning. There is no significant difference between learning rates in rich environments for social learning.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 26/05/2025

We then ran a within-subjects 2x2 design as an online experiment. Each participant completed two armed bandits in rich and poor environments, and while learning socially or individually.

Experiment design: participants went through poor and rich environments for both individual and social learning conditions. In the individual learning condition, they made choices and received direct feedback. In the social learning condition, they observed multiple reviews, before making one choice.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 26/05/2025

What bias is adaptive depends on what kind of environment you're in: in poor environments (rare rewards), a positivity bias is beneficial, while the opposite is true in rich environments. Our simulations show that this holds regardless of individual or social contexts.

Simulation results across poor and rich environments, and individual and social learning. Regardless of learning type, positivity biased agents perform better than negativity biased agents in poor environments, and vice versa.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 26/05/2025

However, one of the major perks of social learning is supposed to be that you can learn from others' mistakes, so you don't have to repeat them yourself. This would imply we should be negativity biased when learning from others. So does the stable positivity bias hold regardless?

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Dr. Alexandra Witt @alexthewitty.bsky.social · 26/05/2025

In individual learning, prior research often reports a stable positivity bias: learning rates for positive prediction errors are higher than those for negative ones (i.e. we update positive outcomes more strongly than negative ones).

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Dr. Alexandra Witt @alexthewitty.bsky.social · 26/05/2025

🚨CogSci preprint alert🚨 When you look at reviews, do you like to focus on positive or negative ones? @stepalminteri.bsky.social, @thecharleywu.bsky.social and I set out to investigate how learning rate biases differ between individual and social learning in our new study. osf.io/bcrw9_v2 🧵 below!

osf.io

OSF

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Reposted by Dr. Alexandra Witt

Charley Wu @thecharleywu.bsky.social · 12/03/2025

👨‍🎤COSMOS strikes back🌠! This time in Tokyo 🇯🇵 with a fantastic new program designed to teach computational modeling of social phenomena. As always, it's free to attend & we will offer travel stipends to ensure diverse attendance. For details visit 👉 cosmossummerschool.github.io/application/ pls share🙏

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Dr. Alexandra Witt @alexthewitty.bsky.social · 23/09/2024

Secret 8/7 -- if you don't have access to PNAS, the preprint is also still around osf.io/preprints/ps... 🔓

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Dr. Alexandra Witt @alexthewitty.bsky.social · 23/09/2024

Thank you, and good catch! Looks like my 🎉got parsed into the link by accident. Here's the paper: www.pnas.org/doi/10.1073/... :)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 23/09/2024

7/7 I'm beyond thrilled that this project is officially published now, and forever grateful to my collaborators, without whom this would've been impossible -- @watarutoyokawa.bsky.social, Kevin Lala, Wolfgang Gaissmaier, and @thecharleywu.bsky.social. Now off with you! Go read the full paper!

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Dr. Alexandra Witt @alexthewitty.bsky.social · 23/09/2024

6/7 Participants used social information as an exploration tool: when it was possible to learn from others, they reduced the amount of directed individual exploration they did -- this might be resource-rational, given that exploration has been found to be cognitively costly.

A plot showing the value of the directed exploration parameter within participant across condition (solo vs. group rounds). Directed exploration is significantly higher in solo than in group rounds.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 23/09/2024

5/7 Participants adjusted how much they relied on social information to the task -- when we lowered social correlations, they stopped using social information altogether.

A plot showing the protected exceedance probability (a measure of model fit) across different social correlations. Asocial Learning is the best fitting model when social correlations are low (0.1), while Social Generalization is the best fitting model at correlations of 0.6.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 23/09/2024

4/7 Participants treated social information as noisy individual information, following the predictions of our Social Generalization model. They also performed better when they relied on social information, using it to their advantage.

A plot showing the significant negative correlation between social noise (a parameter that is low when relying on social information) and mean reward.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 23/09/2024

3/7 To investigate how humans handle settings where preferences are non-identical, we ran 3 experiments using the socially correlated bandit -- a task in which social information is helpful, but imitation is not optimal.

A screenshot of the socially correlated bandit task. Groups of 4 participants explore spatially correlated bandits, which are also socially correlated. They have a limited number of clicks to explore, and are trying to maximize their payoff.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 23/09/2024

2/7 In prior research on how we can computationally model social learning, participants and demonstrators generally shared the exact same goal, making imitation optimal. In real life, however, you might not want to blindly imitate any person you come across.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 23/09/2024

How do we integrate social information from others with similar, but distinct, preferences? Find the answer in the first publication of my PhD, now out in PNAS! (pnas.org/doi/10.1073/... Or get the quick rundown in the thread below 🧵

Multiple people give different star ratings about the same product

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Dr. Alexandra Witt @alexthewitty.bsky.social · 25/07/2024

Ever had to go through the gruelling process of finding a good restaurant based on Google reviews? 🍝 Come check out my poster today to learn how humans use social information from others with similar, but nonidentical, tastes! #CogSci2024 (P1-LL-178!)

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Reposted by Dr. Alexandra Witt

Senne Braem @sebraem.bsky.social · 27/03/2024

We're looking for a new PhD student to come and work with us on the topics of cognitive control and reinforcement learning! Deadline April 26th. For more information, please see users.ugent.be/~sbraem/

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Dr. Alexandra Witt @alexthewitty.bsky.social · 22/03/2024

Happy to share that I recently started a research visit at the @velezcolab.bsky.social - looking forward to collaborating with the experts on collaboration, and to delve back into neuroscience 🥳 🧠

The poster is standing in front of the Princeton Neuroscience Institute and pointing at the sign.

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Dr. Alexandra Witt @alexthewitty.bsky.social · 27/02/2024

This work wouldn't have been possible without my supervisor @thecharleywu.bsky.social as well as our lovely collaborators @watarutoyokawa.bsky.social, Kevin Lala, and Wolfgang Gaissmaier. Immensely grateful to all of them for their help, and to you for reading this far! :)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 27/02/2024

In our second experiment, we additionally compared individual and social behaviour. We find evidence that social information use partially replaces potentially costly exploration. In our case, this also made participants perform better at the task - win-win! (6/7)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 27/02/2024

Using simulations, we can show that this is optimal in our task setup, and can be seen as an extension of prior models to more general settings, i.e. not everyone having the same preferences, skills, or goals. (5/7)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 27/02/2024

Across two experiments (one of them a preregistered replication), we find that participants in this task are best described by a Social Generalization model, which treats social information as noisier individual information (taking it with a grain of salt, perhaps? 🧂) (4/7)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 27/02/2024

Instead, there are some things everyone looks for in a good restaurant (high ingredient quality, hygiene standards), while others are matters of taste. We formalize this idea into a socially correlated bandit task, where learning from others is good, but imitation isn't optimal. (3/7)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 27/02/2024

Prior research on social learning has often been limited to cases where the demonstrator and learner share identical goals. But when you're asking a friend for restaurant recommendations, it's probably not because your tastes are identical. (2/7)

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Dr. Alexandra Witt @alexthewitty.bsky.social · 27/02/2024

Super stoked to announce that the preprint for my first PhD project is out! 🥳 In everyday life, we often rely on other people's opinions, despite them not sharing our exact preferences. But how do we do this adaptively? Find out in this 🧵 (1/7) or here: osf.io/e4g3q

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Reposted by Dr. Alexandra Witt

Natalia Vélez @natvelali.bsky.social · 22/02/2024

Our fearless inaugural lab manager @bellafascendini.bsky.social is going to grad school (🥳🎉), so the CoLab is hiring a lab manager!! Please share with anyone who wants to deepen their experience in cog sci before grad school. Review starts on 3/15! research-princeton.icims.com/jobs/18575/r...

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Wataru Toyokawa @watarutoyokawa.bsky.social · 04/01/2024

📣 We are hiring!! 📣 A postdoc position in the Computational Group Dynamics (COGNAC) lab, RIKEN CBS, Tokyo (Wako). Starting in April 2024 or soon after. Interested in experimenting human collective behaviour? See full details 👉 cbs.riken.jp/en/careers/2... Please Repost 🙏

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Reposted by Dr. Alexandra Witt

Nivi Mani @nivimani.bsky.social · 22/11/2023

Been saving this for my first post here. As part of a new Research Training Group on Curiosity to be established at Göttingen (www.uni-goettingen.de/de/681631.html), we advertise a PhD position in developmental curiosity research in my group. More details here: www.uni-goettingen.de/de/document/...

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Jeremy Hogeveen @jeremyhogeveen.bsky.social · 02/12/2023

New paper alert: a mini meta analysis of human studies related to exploration and exploitation. Hopefully the start of a great collab with this team! www.sciencedirect.com/science/arti...

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Reposted by Dr. Alexandra Witt

Chaz Firestone @chazfirestone.bsky.social · 20/11/2023

Out today! www.pnas.org/doi/10.1073/...

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