ArticleProceedings of the National Academy of Sciences of the United States of America2021
An implicit representation of stimulus ambiguity in pupil size.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.
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10 citing papers in PubMed.
- Pupil size predicts exploration through critical slowing in prefrontal dynamics.Communications biology · 2025Article
- Pupil size predicts the onset of exploration and changes in prefrontal dynamics.bioRxiv : the preprint server for biology · 2025Article
- Pupillometry: A Simple and Automatic Way to Explore Implicit Cognitive Processing.Bio-protocol · 2025Article
- Pupil Size Tracks the Effects of Global Context and Semantic Ambiguity on Word-Meaning Processing.Journal of cognition · 2025Article
- Multi-level processing of emotions in life motion signals revealed through pupil responses.eLife · 2024Article
- Perceptual awareness of near-threshold tones scales gradually with auditory cortex activity and pupil dilation.iScience · 2024Article
- Introspective inference counteracts perceptual distortion.Nature communications · 2023Article
- Article
- A unitary model of auditory frequency change perception.PLoS computational biology · 2023Article
- Implicit and Explicit Voice Training Effects on Speech-on-Speech Perception and Listening Effort.Ear and hearingArticle
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4 authors.
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Abstract
To guide behavior, perceptual systems must operate on intrinsically ambiguous sensory input. Observers are usually able to acknowledge the uncertainty of their perception, but in some cases, they critically fail to do so. Here, we show that a physiological correlate of ambiguity can be found in pupil dilation even when the observer is not aware of such ambiguity. We used a well-known auditory ambiguous stimulus, known as the tritone paradox, which can induce the perception of an upward or downward pitch shift within the same individual. In two experiments, behavioral responses showed that listeners could not explicitly access the ambiguity in this stimulus, even though their responses varied from trial to trial. However, pupil dilation was larger for the more ambiguous cases. The ambiguity of the stimulus for each listener was indexed by the entropy of behavioral responses, and this entropy was also a significant predictor of pupil size. In particular, entropy explained additional variation in pupil size independent of the explicit judgment of confidence in the specific situation that we investigated, in which the two measures were decoupled. Our data thus suggest that stimulus ambiguity is implicitly represented in the brain even without explicit awareness of this ambiguity.
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