Human observers have optimal introspective access to perceptual processes even for visually masked stimuli
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Many believe that humans can ‘perceive unconsciously’ – that for weak stimuli, briefly presented and masked, above-chance discrimination is possible without awareness. Interestingly, an online survey reveals that most experts in the field recognize the lack of convincing evidence for this phenomenon, and yet they persist in this belief. Using a recently developed bias-free experimental procedure for measuring subjective introspection (confidence), we found no evidence for unconscious perception; participants’ behavior matched that of a Bayesian ideal observer, even though the stimuli were visually masked. This surprising finding suggests that the thresholds for subjective awareness and objective discrimination are effectively the same: if objective task performance is above chance, there is likely conscious experience. These findings shed new light on decades-old methodological issues regarding what it takes to consider a neurobiological or behavioral effect to be 'unconscious,' and provide a platform for rigorously investigating unconscious perception in future studies.
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Another possible method for measuring consciousness is the use of metacognitive judgments such as confidence ratings.
“Another possible method for measuring consciousness is the use of metacognitive judgments such as confidence ratings (e.g.Peters & Lau 2015).”
From Consciousness in Artificial Intelligence: Insights from the Science of Consciousness (2023) · cites this paper as Peters & Lau 2015
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- Authors
- Peters, M. A. K., & Lau, H.
- Affiliations
- University of California, Los Angeles (US)
- Corresponding author
- Peters, Megan A K
- Venue
- eLife
- Publisher
- eLife Sciences Publications, Ltd
- Published
- 2015-10-03
- Volume
- 4
- Pages
- e09651-e09651
- ISSN
- 2050-084X (ISSN-L)
- PMC
- PMC4749556
- OpenAlex
- W2192933481
- Cited by
- 197
- References
- 8
- Citations by year
- 2026: 6 · 2025: 12 · 2024: 40 · 2023: 40 · 2022: 21 · 2021: 17 · 2020: 14 · 2019: 9 · 2018: 11 · 2017: 17 · 2016: 10
- FWCI
- 6.93
- Type
- journal article
- Language
- en
- Update notices
- correction (2016-03-31)
- Open access
- gold
- doi.org
- Licence
- Locations
- eLife (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- eScholarship (California Digital Library) (submittedVersion)
- eScholarship (California Digital Library) (submittedVersion, cc-by)
- The HKU Scholars Hub (University of Hong Kong) (submittedVersion, cc-by-nc-nd)
- Funders
- National Institutes of Health (R01NS088628)
- Topics
- Life Sciences › Neuroscience › Cognitive Neuroscience › Visual perception and processing mechanisms
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Philosophy and Theoretical Science
- Life Sciences › Neuroscience › Cognitive Neuroscience › Memory Processes and Influences
- Keywords
- unconscious perception, visual masking, introspective access, subjective confidence, Bayesian ideal observer, subjective experience, discrimination thresholds, methodological quality
- MeSH terms
- Adult, Brain, Female, Humans, Male, Neurobiology, Perception, Young Adult
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