Neuroscience of Consciousness
January 1, 2024
Clara Colombatto, Stephen M Fleming
71 citations
A majority of a sample of 300 US residents were willing to attribute some possibility of phenomenal consciousness—subjective experiences like feelings and sensations—to large language models. These attributions were robust, predicting attributions of mental states typically linked to phenomenality, but also flexible, as they varied with individual differences such as how often participants used the technology. The findings suggest that folk intuitions about AI consciousness can diverge from expert views, with potential implications for the legal and ethical treatment of AI.
Neuroscience and Biobehavioral Reviews
March 1, 2025
Liad Mudrik, Melanie Boly, Stanislas Dehaene et al.
68 citations
In a structured public debate at the 2022 meeting of the Association for the Scientific Study of Consciousness, proponents of five major theories—Global Neuronal Workspace Theory, Higher-Order Theories, Integrated Information Theory, Recurrent Processing Theory, and Predictive Processing—clarified their theories' core mechanisms, foundational premises, and what each theory aims to explain. The discussion revealed more controversy than agreement, particularly on the most basic questions: what consciousness is, how to identify conscious states, and what any adequate theory must account for. Addressing these foundational disagreements is essential for advancing the field and enabling meaningful comparison of competing theories.
The Behavioral and brain sciences
April 21, 2025
Stephen M Fleming, Matthias Michel
26 citations
Conscious vision is surprisingly slow, with unconscious integration windows lasting up to 400 milliseconds, as shown by postdictive effects. Because it is slow, conscious vision cannot guide online actions; instead, it evolved to support offline cognition, such as planning and internal simulation. This shift likely accompanied the water-to-land transition, where larger terrestrial visual horizons made model-based planning advantageous over the fast, reflexive actions typical of aquatic environments. The capacity for internal simulation created pressure for reality monitoring—distinguishing internal from external signals and solving when to stop integrating evidence to fix a model of reality. This reality monitoring function is linked to the emergence of consciousness, in line with higher-order theories. The account generates novel predictions about conscious versus unconscious vision in aquatic and terrestrial animals.
Trends in Cognitive Sciences
July 17, 2024
Stephen M Fleming, Nicholas Shea
26 citations
The quality space hypothesis holds that conscious sensory states, such as colors, are experienced in relation to one another—red feels more like orange than like green or blue. Recent evidence indicates that subjective similarity among experiences can be explained by similarities in neural activation patterns. This review examines how localist, workspace, and higher-order theories of consciousness can account for the qualitative character of experience and functionally support a quality space. Existing empirical evidence for each theoretical position is assessed, and novel experimental methods—including altering local activation spaces through brain stimulation or behavioral training—are highlighted as ways to distinguish among these accounts.
Journal of Vision
May 1, 2024
Nadine Dijkstra, Matan Mazor, Stephen M Fleming
9 citations
Perceptual reality monitoring errors can lead individuals to confuse imagined experiences with real ones. In two experiments involving 150 participants, confidence ratings aligned with decision-making shifts, indicating failures in distinguishing reality at both perceptual and metacognitive levels. While participants showed overall awareness of their errors, this insight did not correlate with specific trial-level confidence. These findings suggest that confidence does not effectively differentiate between imagination and reality during perception, highlighting the complexity of how we assess our own experiences.
PNAS Nexus
February 1, 2024
Benjy Barnett, Lau M Andersen, Stephen M Fleming et al.
7 citations
Perceptual vividness—the intensity of conscious experience—varies across different experiences, but how the brain registers this variation is unclear. In other psychological domains like number or reward, magnitude is represented independently of sensory features. Reanalyzing existing magnetoencephalography and functional MRI data from two studies that quantified vividness via subjective awareness and visibility ratings, evidence emerged for content-invariant neural signatures of vividness distributed across visual, parietal, and frontal cortices. These findings suggest that neural correlates of subjective vividness may share properties with magnitude codes in other cognitive domains.
Communications Psychology
May 21, 2025
Nicolás Sánchez-Fuenzalida, Simon van Gaal, Stephen M Fleming et al.
3 citations
Confidence reports during perceptual decision-making do not uniquely reflect subjective experience. Across two experiments with 204 participants and three bias manipulations, non-perceptual factors such as changes in stimulus base rates or asymmetric payoff matrices leaked into confidence judgments. This shows that confidence can be influenced by response biases unrelated to actual perception, complicating its use as a pure measure of subjective experience. The relative strength of biases in first-order choices versus confidence may help distinguish whether a manipulation truly alters perception or only affects decision strategy.
Nature Mental Health
June 1, 2026
George E. Chapman, Philip R. Corlett, Stephen M Fleming et al.
Fixed, false beliefs called delusions are a core feature of psychotic disorders, but why they remain fixed is not well understood. This review proposes a clearer vocabulary for describing delusion fixity—using the terms conviction, incorrigibility, persistence, and stability—and examines factors from diagnosis, psychopathology, psychodynamics, social context, cognition, metacognition, and cognitive neuroscience that may influence fixity. The authors present a working model of delusion fixity and call for interdisciplinary longitudinal studies to better understand it and to improve therapeutic strategies.
Trends in Cognitive Sciences
July 7, 2026
Nicolas W Schuck, Marit Petzka, Stephen M Fleming
Neural replay, the reactivation of patterns of brain activity, can now be studied noninvasively in humans. While human research has aimed to align with rodent findings, it often implicitly assumes that replay is tied to conscious, deliberate thought. This assumption limits the investigation of how replay relates to consciousness and overlooks broader cross-species differences.
Trends in Cognitive Sciences
June 1, 2026
Patrick Butlin, Robert Long, Tim Bayne et al.
A method for assessing whether AI systems might be conscious is presented, drawing on existing neuroscientific theories of consciousness. The approach involves deriving indicators from such theories to inform beliefs about AI consciousness. This method can make progress because computational functionalist theories, which are influential, have empirically testable implications for AI. The work does not claim that any current AI is conscious but outlines a rigorous framework for future assessment.
Nature Communications
May 8, 2026
Nicolás Sánchez-Fuenzalida, Chris Jungerius, Stephen M Fleming et al.
A key challenge in consciousness research is separating genuine conscious perception from non-perceptual biases when observers report whether they saw a stimulus. In experiments with 505 participants who detected and reproduced dim or absent visual patterns under different conditions—attentional cues, asymmetrical base rates, and payoff schemes—a Hurdle-Gaussian model decomposed responses into a perceptual continuous component and a non-perceptual hurdle component. Statistical priors and reward structures shifted the non-perceptual hurdle, while attentional cues selectively shifted the perceptual component, consistent with changes in conscious experience. Crucially, including detection trials contaminated reproduction reports with non-perceptual criterion effects, urging caution in interpreting detection-based measures in consciousness research.
Trends in Cognitive Sciences
March 1, 2024
Tim Bayne, Anil K. Seth, Marcello Massimini et al.
New tests for consciousness (C-tests) are urgently needed to resolve uncertainty about when consciousness arises in human development, when it is lost due to neurological disorders and brain injury, and how it is distributed in nonhuman species. This need is amplified by recent developments in AI, neural organoids, and xenobot technology. Existing C-tests are of limited use, and no tests exist for many critical populations. The paper identifies challenges facing any attempt to develop C-tests, proposes a multidimensional classification of such tests, and identifies strategies for validating them.
arXiv Preprint Archive
August 17, 2023
Patrick Butlin, Robert Long, Eric Elmoznino et al.
No current AI systems are conscious, but there are no obvious technical barriers to building ones that might be, according to an analysis grounded in neuroscientific theories of consciousness. The report surveys prominent theories—recurrent processing, global workspace, higher-order, predictive processing, and attention schema—and derives computational indicator properties from them. Applying these indicators to recent AI systems yields no evidence of consciousness, but the authors argue that future systems could potentially implement the necessary properties.
Alzheimer's & dementia (New York, N. Y.)
January 1, 2021
Jonathan Huntley, Stephen M Fleming, Daniel C Mograbi et al.
People with Alzheimer's disease show a range of changes in consciousness, including reduced awareness of cognitive deficits, diminished self-awareness, and impaired introspection, which appear early and worsen as the disease progresses. These awareness impairments are linked to brain damage in areas that overlap with proposed neural correlates of consciousness. The authors argue that recognizing Alzheimer's disease as a disorder of consciousness is overdue and important for understanding patients' lived experience and improving care.
arXiv Preprint Archive
May 31, 2019
Stephen M Fleming
Humans can report being aware of something, but the decision processes behind such reports are poorly understood. This article proposes a computational framework treating awareness reports as metacognitive inferences about a generative model of perceptual content. Internal states supporting awareness reports are simple and abstract, varying along a one-dimensional continuum from absent to present. A critical feature is that this architecture is higher-order and asymmetric: many perceptual states are nested under "present," but far fewer under "absent." Simulations show this asymmetry naturally accounts for "global ignition" observations in brain-imaging studies of awareness reports.
Frontiers in Psychology
November 5, 2018
Matthias Michel, Stephen M Fleming, Hakwan Lau et al.
A survey of 249 participants, mostly in academia and about 40% experts in consciousness research, assessed views on the field's progress, funding, job opportunities, and scientific rigor. 78% of respondents said scientific research on consciousness has been making progress. However, most perceived obtaining funding and getting a job in consciousness research as more difficult than in other neuroscience subfields. Work in consciousness research was seen as less rigorous than other neuroscience subfields, but this perception was not linked to the perceived difficulty in funding and jobs. Global workspace theory was rated most promising overall (about 28%), while among non-experts integrated information theory (IIT) was most popular (about 22%).