iiinova — where your digital self keeps evolving

Pascal Mamassian @mamassian.bsky.social · 17/09/2026

Congratulations to Dr Tarryn Balsdon for beautifully defending her “Habilitation à Diriger des Recherches”, i.e. autorisation to officially supervise her own PhD students!!!

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Pascal Mamassian @mamassian.bsky.social · 11/07/2026

Deeply honoured and very humbled to have received the 2026 Kurt Koffka Medal. Many thanks to the committee at the University of Giessen! www.uni-giessen.de/fbz/fb06/psy...

Pascal Mamassian (centre) receiving the 2026 Kurt Koffka Medal from Prof. Dr. Christiane Hermann (left) and Prof. Dr. Roland W. Fleming at the University of Giessen, Germany, on July 8, 2026.

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Pascal Mamassian @mamassian.bsky.social · 19/04/2026

A classic painting from the Mexican artist Octavio Ocampo. Try rotating the image upside-down if you don't see anything strange at first.

Octavio Ocampo (1992) “Equality”.
The mirror reflection of the woman's face is perceived as a man's face.

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Pascal Mamassian @mamassian.bsky.social · 03/04/2026

In this image, the square tiles look like diamond shapes when light grazes the surface. (The square tiles are actually floor heating elements) Probably related to the coffer illusion by Anthony Norcia.

Floor heating elements that have a square shape look like diamond tiles when light grazes the surface.

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Pascal Mamassian @mamassian.bsky.social · 16/03/2026

Congratulations to Ian Thornton and colleagues who published their Mainz-Linez illusion in i-Perception (@pec-ipe.bsky.social): the red dots appears to wave left and right when one looks at one of the black dots, but they actually move straight journals.sagepub.com/doi/10.1177/...

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Pascal Mamassian @mamassian.bsky.social · 20/02/2026

The European Summer School "Visual Neuroscience" in Rauischholzhausen castle, Germany, is coming back in 2026! Deadline: 8 March 2026 www.allpsych.uni-giessen.de/rauisch/

Flyer for 2026 edition of the European Summer School "Visual Neuroscience" in Rauischholzhausen castle, Germany.

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Pascal Mamassian @mamassian.bsky.social · 05/01/2026

Are we ready to tackle perceptual segmentation of natural scenes? Finally the review on perceptual segmentation you’ve been waiting for! www.sciencedirect.com/science/arti...

An illustration of how human perceptual segmentation and integration (PSI) of natural stimuli and image segmentation algorithms can be bridged.

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Pascal Mamassian @mamassian.bsky.social · 20/12/2025

This head is spinning continuously, but we see it rotating back and forth... ...presumably because of our strong prior expectation that faces are convex. This is a very nice example of the Hollow-Face illusion promoted by Richard Gregory: www.richardgregory.org/experiments/

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Pascal Mamassian @mamassian.bsky.social · 26/09/2025

We found that motion features were encoded in a temporally ordered sequence: orientation and spatial frequency emerged within 120 ms after stimulus onset, while temporal frequency and direction followed at later latencies. [2/3]

Graphical abstract of the main results of the study by Thomas Schaffhauser

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Pascal Mamassian @mamassian.bsky.social · 24/09/2025

A nice shift in perceived colour between central and peripheral vision. The fixated disc looks purple while the others look blue. The effect presumably comes from the absence of S-cones in the fovea. From Hinnerk Schulz-Hildebrandt: arxiv.org/pdf/2509.115...

An array of 9 purple discs on a blue background. Figure from Hinnerk Schulz-Hildebrandt.

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Pascal Mamassian @mamassian.bsky.social · 22/04/2025

The model can also fit continuous confidence ratings without binning these ratings. Matlab code here: github.com/mamassian/cn... (4/4)

modelling of continuous confidence judgments

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Pascal Mamassian @mamassian.bsky.social · 22/04/2025

Critically, the model includes a parameter that reflects whether confidence relies on the same information that was used for perceptual decisions, or some new information. We describe two ways to estimate this Confidence Boost parameter. (3/4)

estimation of confidence boost parameter

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Pascal Mamassian @mamassian.bsky.social · 22/04/2025

The CNCB (Confidence-Noise Confidence-Boost) model can be seen as an alternative to the popular meta-d’ and M-ratio analyses. It can take more than two stimulus strengths and is a bit more tolerant to sensory biases. (2/4)

effect of sensory criterion on confidence efficiency

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Pascal Mamassian @mamassian.bsky.social · 22/04/2025

If you work with perceptual confidence judgments, you may be interested in our CNCB model of confidence ratings. Joint work with Vincent de Gardelle. Uncorrected proofs here: dx.plos.org/10.1371/jour... (🧵 1/4)

relationship between sensory evidence and confidence evidence

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Pascal Mamassian @mamassian.bsky.social · 12/04/2025

Why is it so difficult for Large Language Models to properly read time? arxiv.org/abs/2502.05092

Erroneous clock time readings from different LLMs

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Pascal Mamassian @mamassian.bsky.social · 12/03/2025

The dynamic version is even more disturbing...

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Pascal Mamassian @mamassian.bsky.social · 27/01/2025

Congratulations! Richard Gregory probably helped to popularize the cultural hypothesis in his nice 1966 book “Eye and Brain”. But since then, isn’t the dominant theory related to a misuse of the low spatial frequency content of the image (its blurred part)? See e.g. doi.org/10.1068/p150...

The Müller-Lyer illusion on the left, and a blurred copy on the right that might be responsible for the illusion.

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Pascal Mamassian @mamassian.bsky.social · 24/01/2025

I agree that the coming and going of 3D perceptions makes this animation interesting! A nice development on the “stereokinetic effect” of Cesare Musatti a century ago, and more recently of the work of Zili Liu (UCLA): doi.org/10.1016/j.vi... original post here: bsky.app/profile/jcpo...

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Pascal Mamassian @mamassian.bsky.social · 22/12/2024

Interestingly, another model, “GPT-4o”, is also biased like humans, but it can generate some python code to analyse the image pixel by pixel to correct its error Overall, I agree with Tomer that it is not clear why we would want these models to fall for illusions the way humans do. 4/4

the model “GPT-4o” is also biased but has the option to check its answer

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Pascal Mamassian @mamassian.bsky.social · 22/12/2024

The model also “knows” that the effect is orientation dependent www.sciencedirect.com/science/arti... 3/4

the model “Claude” is also biased in the rotated version of the illusion

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Pascal Mamassian @mamassian.bsky.social · 22/12/2024

As predicted, it is also reporting the illusion when the lines are un-equal (“illusion-illusion”), and it explicitly refers to the vertical-horizontal illusion. 2/4

the model “Claude” is also biased when there is no illusion

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Pascal Mamassian @mamassian.bsky.social · 22/12/2024

Very interesting analysis! I have tried the vertical-horizontal illusion in its classic configuration. The model “Claude” is reporting the human-biased percept when the lines are physically equal (“illusion”) 1/4

the model "Claude" is biased by the vertical-horizontal illusion

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Pascal Mamassian @mamassian.bsky.social · 08/12/2024

Cast shadows are indeed so powerful! Here is another related picture from the following chapter that Dan Kersten and I wrote: hal.science/hal-03984071/

A man seems to be floating over a road because of a stain on the road that is interpreted as his cast shadow.

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Pascal Mamassian @mamassian.bsky.social · 21/10/2024

It was nice to see that many people interested in time perception at the first FAsT (French Association for Timing) meeting in Saclay last week! fast2024.sciencesconf.org

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Pascal Mamassian @mamassian.bsky.social · 27/11/2023

Happy to share the results of interdisciplinary discussions between scientists and artists on colour (in French) — Heureux de partager les résultats de discussions interdisciplinaires entre scientifiques et artistes sur la couleur (en français) doi.org/10.3917/herm...

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