Matan Mazor

@matanmazor.bsky.social

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Interested in complex systems and in simple systems that believe they are complex systems. Head of the Oxford Self-Modelling Group (Dept. of Experimental Psychology, University of Oxford)

The human need for rationalizations has shaped consciousness science since its inception. Descartes saw his view that animals were unconscious automatons “not so much cruel to beasts but respectful to human beings… whom it absolves from any suspicion of crime whenever they kill or eat animals” (Descartes, 1999, cited in Kaldas, 2015). More recently, a new wave of biological naturalism, arguing that consciousness is inherently a property of living beings (Aru et al., 2023; Findlay et al., 2024; Seth, 2025) coincided with concerns about the potentially devastating moral implications of conscious AI (Long et al., 2024). As with Fleming and Michel’s fish, or Descartes’ beasts, there may be good epistemic reasons to favour a theory in which AI cannot be conscious. Yet a full understanding of consciousness science requires taking seriously the force of rationalizations in theory formation and selection.
Finally, while Exp. 2 confirmed that confidence in absence is affected by stimulus size in a way that parallels the effect of size on prospective confidence, it also produced a series of disappointing null findings, with no significant effect of size on confidence in presence and no correlations between size effects on post-decisional confidence and on prospective confidence or perceptual sensitivity. Disappointed by these null findings, we reminded ourselves that Exp. 2 had a smaller sample size and only 8 trials per block (half the number of trials in Exp. 1). As such, we are not confident that these correlations are truly absent — we cannot be certain that we would have detected them if they were present.
A) A schematic description of the ideal observer model. B) Comparison of human and simulated data for Exp. 1, for response time, error rate, and confidence. Lines and points represent human data; semi-transparent rectangles represent data simulated from model parameters, which were fitted to reaction time and accuracy (but not confidence) data of individual participants. Rectangles are centred at their mean value, and their height is twice the standard error.
A) visual sensitivity (measured as d’) as a function of stimulus size. B) mean confidence in correct responses as a function of target presence and size. Error bars represent the standard error; ***: p<.001. C) correlations between the effect of size on perceptual sensitivity and on confidence, separately for target-present and target-absent decisions.
Experiment 1. A) Stimuli. Left: example frames from target-present (blue) and target-absent (red) trials. Stimuli refreshed at 15 frames per second until a response was recorded. Right: on different trials, stimuli appeared big or small. C) trial structure. Participants performed two 16-trial detection blocks in which the target was the letter S and two blocks in which the target was the letter A. Stimulus presentation was preceded by a frame, and followed by an analog confidence rating scale. The order of the two letters was randomised between participants.
Some stuff from the paper: reverse correlation, sign consistency, model predictions for subjective confidence, equations, and taylor swift
A figure detailing the experimental paradigm, in which participants made decisions about the presence or absence of letters under different levels of stimulus occlusion.
A table of correlations between model parameters and occlusion effects on accuracy and reaction times, showing that correlations are significant between the parameter that controls the true visibility of stimuli and behaviour on target-present trials, and between the parameter that controls the believed visibility of stimuli and behaviour on target-absent trials.
An ideal observer model of visual detection
The title of the paper, "Beliefs about Perception Shape Perceptual Inference: An Ideal Observer Model of Detection", with the author names, and Fig. 1: a schematic of an inverse optics account of vision.
While browsing through arXiv postings, rambling between shelves of libraries, or sitting in the dining room of an institute, I met heroes and heroines. The last decade of my life was like living a chapter from ancient mythology. There were hundreds of characters, each one of them with a unique set of abilities. It was, and still is, a privilege to have connected with their minds. On clear days, I can see that I am a small and simple part of a big and complex ancient structure, like a mushroom sprouted from a giant underground fungal network. It feels good.