Ryutaro Uchiyama

Gradience as a cognitive principle for evaluating numerical notations | PNAS More than 100 historically, archaeologically and ethnographically attested numerical notations have been used over the past 5,000 y; however, becau...

OK, it finally happened! My new article, "Gradience as a cognitive principle for evaluating numerical notations", is now out today in @pnas.org. By focusing on numerals' use for communication instead of arithmetic, we have a new tool to assess their efficiency.
www.pnas.org/doi/10.1073/...

This difference in cognitive demand plausibly explains the merging of verbal and orthographic imagery.

More broadly, this is a "hidden difference in phenomenal experience" driven by material culture, and thus by the population dynamics of cultural evolution.

onlinelibrary.wiley.com/doi/full/10....

Neural & behavioral data suggest that alphabets are processed as serial transformation from orthography to phonology to meaning, whereas Chinese reading activates parallel encoding of phonology AND orthography, presumably as a neurocognitive adaptation to the statistical structure of the script.

I propose that this "ortho-verbal conjunction" may be a downstream consequence of the structural properties of the script. Chinese logographic script is a many-to-few mapping from 10,000s of symbols to several hundred sounds, imposing cognitive demands that differ qualitatively from alphabets

In the original US sample, an exploratory factor analysis revealed that orthographic imagery (mental representation of written symbols) and internal verbalization ("inner speech") constitute separate factors. In the present Chinese sample, these 2 modalities were merged into a single factor.

Sage Journals: Discover world-class research Subscription and open access journals from Sage, the world's leading independent academic publisher.

New paper out in Cross-Cultural Research:

Using Roebuck & @glupyan.bsky.social's Internal Representations Questionnaire, I test the preregistered hypothesis that writing systems shape the modality of mental imagery, with data from China and Japan.
journals.sagepub.com/doi/10.1177/...

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thank you!

thanks, could you share a link?

New paper for the Theory of Mind for AI workshop at AAAI Conference for Artificial Intelligence

I propose that ToM mechanisms are used not only for social cognition, but also for calibrating the dimensionality of motor exploration in cumulatively cultural skill acquisition

arxiv.org/abs/2601.01599

My new lab in Singapore is seeking a full-time RA to help investigate how exploratory cognitive states shape environmental representations (cognitive maps). The position is funded until late 2027, and comes with a postdoc-level salary package. Please forward!

careers.sutd.edu.sg/job/Singapor...

A Voyage Into the Art of Finding One’s Way at Sea

A Voyage Into the Art of Finding One’s Way at Sea www.nytimes.com/2025/11/18/s...

Congrats Witt博士, have a blast in Tokyo/Saitama

I’m recruiting PhD students at NYU (start Sept 2026).
Focus: cultural evolution, innovation & cooperation, AI & society, progress studies & development.

Deadline to apply is Dec 1- very soon.

I’ll share more about the move & new work soon.

Please share with students & retweet!

@glupyan.bsky.social
@michael.muthukrishna.com

Today is #alife2025 day 1! Workshops under way... We have our own workshop tmw on Cultural Evolution of Planet X, 13.30-16.30, room 4F. Exciting keynotes from James Borg and @uchiyama.bsky.social. Join us!

Next Tuesday: giving a keynote talk for the "Cultural Evolution of Planet X" workshop at the International Conference for Artificial Life, Kyoto @alife2025.bsky.social

Talk title, "Developmental complexity in cultural environments"; workshop is 13:30–16:30 Oct 7. If you're at ALIFE, please drop by!

Looking forward to my conversation with the Asian Cultural Evolution Seminar on zoom 29 July 🌏

🤯

Expressing fear enhances sensory acquisition - Nature Neuroscience This behavioral study finds that when subjects pose expressions of fear, they have a subjectively larger visual field, faster eye movements, and an increase in nasal volume and air velocity during bre...

Disgust is not only a behavioral state but also a sensory one, prioritizing fine-grained perceptual discrimination, whereas fear prioritizes sensory detection. Functionally similar to "what" vs "how". Motoric "how" is more important for predators. Might help explain.

www.nature.com/articles/nn....

🏰 PhD position on computational modelling | collective dynamics | cultural evolution 🏰

Get in touch with any questions you might have and join me in beautiful Marburg!

stellenangebote.uni-marburg.de/jobposting/c... (Deutsch)

stellenangebote.uni-marburg.de/jobposting/3... (English)

Postdoctoral position in Palaeolithic gene-culture coevolution, Department of Archaeology and Heritage Studies, Aarhus University - Vacancy at Aarhus University Vacancy at School of Culture and Society - Department of Heritage Studies, Aarhus University

3) 2.5 yr postdoctoral position in Palaeolithic gene-culture coevolution. Together with a palaeogenomics postdoc, we seek to generate material culture data such that we can capture these ancient gene-culture cophylogenetic dynamics international.au.dk/about/profil...

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

Welcome 🙏

🇺🇳 the UN just dropped their first report on AI governance. Discussion of governance as an enabler rather than hindrance — parallels with programs for vaccine equity (GAVI) and scientific coordination (CERN, EMBL). Regarding risks, they seem aware of vast unknown unknowns

www.un.org/en/ai-adviso...

Group leader position in comp-psych / cross-cult-psych at MPI EVA in Leipzig (Haun group). 6 years (+2). Deadline January 31st. Details here:
www.eva.mpg.de/career/posit...

This is so cool:
www.pnas.org/doi/10.1073/...
Bacteria store a memory of swarming proficiency (measured as the time lag to start swarming on suitable media) in the form of intracellular iron levels. This memory can be passed down for 4 generations!

indirect effects of collective action in journal-land

Figure 2, learning curriculum effects

Title and abstract of paper

Curriculum learning with infant egocentric video: really nice paper showing that young infants’ visual experience provides better learning input for computer vision models. openreview.net/pdf?id=zkfyO...

New TICS paper by Baumard et al— a masterful, panoramic theory of how to infer historical psychologies using cultural products as data

📚💀 Cognitive fossils: using cultural artifacts to reconstruct psychological changes throughout history

www.sciencedirect.com/science/arti...