medRxiv
August 31, 2026
Jonathan Huntley, Benjy Barnett, Daniel Bor et al.
preprint
Despite extensive knowledge of the progressive sequence of cognitive and functional deficits in Alzheimer's Disease (AD), the impact of neurodegeneration on the conscious experience of patients remains largely unexplored. Understanding how the content of consciousness, particularly perceptual awareness, changes with the progression of AD is crucial to enable meaningful person-centred care. This...
Trends in Cognitive Sciences
July 7, 2026
Nicolas W Schuck, Marit Petzka, Stephen M Fleming
Noninvasive methods are making it possible to study neural replay in humans. Although focused on alignment with rodent findings, human research often tacitly assumes that replay is linked to conscious, deliberate thought. This assumption represents a missed opportunity to investigate the links between replay and consciousness, as well as cross-species differences more broadly.
The Behavioral and brain sciences
June 25, 2026
Stephen M Fleming, Matthias Michel
Our response to commentaries further clarifies the links between visual postdictive phenomena, conscious experience, reality monitoring, and planning. We also engage with suggestions about the limits and generality of our conclusions for other sensory modalities and visually guided behavior in aquatic organisms. We conclude that the role of sensory horizons in visual consciousness offers...
Nature Mental Health
June 1, 2026
George E. Chapman, Philip R. Corlett, Stephen M Fleming et al.
Delusions are a key feature of psychotic disorders, yet their fixity remains underexplored. Here, the authors propose a refined vocabulary for delusion fixity, review influencing factors, and present a working model. The Review calls for interdisciplinary longitudinal studies that could enhance the understanding of delusion fixity and facilitate the advancement of therapeutic strategies. Fixed,...
Trends in Cognitive Sciences
June 1, 2026
Patrick Butlin, Robert Long, Tim Bayne et al.
Rapid progress in artificial intelligence (AI) capabilities has drawn fresh attention to the prospect of consciousness in AI. There is an urgent need for rigorous methods to assess AI systems for consciousness, but significant uncertainty about relevant issues in consciousness science. We present a method for assessing AI systems for consciousness that involves exploring what follows from...
Nature Communications
May 8, 2026
Nicolás Sánchez-Fuenzalida, Chris Jungerius, Stephen M Fleming et al.
A central challenge in consciousness research is determining whether observers have a conscious experience of a stimulus. However, present/absent detection judgments are often biased by contextual factors, making it difficult to isolate conscious perception from non-perceptual influences. Traditional psychophysical methods struggle to disentangle these components. To address this, we conducted...
Communications Psychology
May 21, 2025
Nicolás Sánchez-Fuenzalida, Simon van Gaal, Stephen M Fleming et al.
3 citations
In noisy perceptual environments, people frequently make decisions based on non-perceptual information to maximize rewards. Therefore, a central problem in psychophysics, metacognition and consciousness research is to distinguish between decisions resulting from changes in subjective experience and those arising from non-perceptual information. It has recently been proposed that confidence...
The Behavioral and brain sciences
April 21, 2025
Stephen M Fleming, Matthias Michel
26 citations
It is not obvious why we are conscious. Why can't all of our mental activities take place unconsciously? What is consciousness for? We aim to make progress on this question, focusing on conscious vision. We review evidence on the timescale of visual consciousness, showing that it is surprisingly slow: postdictive effects reveal windows of unconscious integration lasting up to 400 milliseconds....
Neuroscience and Biobehavioral Reviews
March 1, 2025
Liad Mudrik, Melanie Boly, Stanislas Dehaene et al.
68 citations
As the field of consciousness science matures, the research agenda has expanded from an initial focus on the neural correlates of consciousness, to developing and testing theories of consciousness. Several theories have been put forward, each aiming to elucidate the relationship between consciousness and brain function. However, there is an ongoing, intense debate regarding whether these...
Trends in Cognitive Sciences
July 17, 2024
Stephen M Fleming, Nicholas Shea
26 citations
The quality space hypothesis about conscious experience proposes that conscious sensory states are experienced in relation to other possible sensory states. For instance, the colour red is experienced as being more like orange, and less like green or blue. Recent empirical findings suggest that subjective similarity space can be explained in terms of similarities in neural activation patterns....
Journal of Vision
May 1, 2024
Nadine Dijkstra, Matan Mazor, Stephen M Fleming
9 citations
Perceptual reality monitoring refers to the ability to distinguish internally triggered imagination from externally triggered reality. Such monitoring can take place at perceptual or cognitive levels-for example, in lucid dreaming, perceptual experience feels real but is accompanied by a cognitive insight that it is not real. We recently developed a paradigm to reveal perceptual reality...
Trends in Cognitive Sciences
March 1, 2024
Tim Bayne, Anil K. Seth, Marcello Massimini et al.
Which systems/organisms are conscious? New tests for consciousness ('C-tests') are urgently needed. There is persisting 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 and rapid developments in artificial intelligence (AI), neural...
PNAS Nexus
February 1, 2024
Benjy Barnett, Lau M Andersen, Stephen M Fleming et al.
7 citations
Some conscious experiences are more vivid than others. Although perceptual vividness is a key component of human consciousness, how variation in this magnitude property is registered by the human brain is unknown. A striking feature of neural codes for magnitude in other psychological domains, such as number or reward, is that the magnitude property is represented independently of its sensory...
Neuroscience of Consciousness
2024
Clara Colombatto, Stephen M Fleming
71 citations
Technological advances raise new puzzles and challenges for cognitive science and the study of how humans think about and interact with artificial intelligence (AI). For example, the advent of large language models and their human-like linguistic abilities has raised substantial debate regarding whether or not AI could be conscious. Here, we consider the question of whether AI could have...
arXiv Preprint Archive
August 17, 2023
Patrick Butlin, Robert Long, Eric Elmoznino et al.
Whether current or near-term AI systems could be conscious is a topic of scientific interest and increasing public concern. This report argues for, and exemplifies, a rigorous and empirically grounded approach to AI consciousness: assessing existing AI systems in detail, in light of our best-supported neuroscientific theories of consciousness. We survey several prominent scientific theories of...
Alzheimer's & dementia (New York, N. Y.)
2021
Jonathan Huntley, Stephen M Fleming, Daniel C Mograbi et al.
People with Alzheimer's disease (AD) demonstrate a range of alterations in consciousness. Changes in awareness of cognitive deficit, self-awareness, and introspection are seen early in AD, and dysfunction of awareness and arousal progresses with increasing disease severity. However, heterogeneity of deficits between individuals and a lack of empirical studies in people with severe dementia...
arXiv Preprint Archive
May 31, 2019
Stephen M Fleming
Humans have the ability to report the contents of their subjective experience - we can say to each other, "I am aware of X". The decision processes that support these reports about mental contents remain poorly understood. In this article I propose a computational framework that characterises awareness reports as metacognitive decisions (inference) about a generative model of perceptual...
Frontiers in Psychology
November 5, 2018
Matthias Michel, Stephen M Fleming, Hakwan Lau et al.
The scientific study of consciousness emerged as an organized field of research only a few decades ago. As empirical results have begun to enhance our understanding of consciousness, it is important to find out whether other factors, such as funding for consciousness research and status of consciousness scientists, provide a suitable environment for the field to grow and develop sustainably. We...
Science (New York, N.Y.)
September 17, 2010
Stephen M Fleming, Rimona S Weil, Zoltán Nagy et al.
The ability to introspect about self-performance is key to human subjective experience, but the neuroanatomical basis of this ability is unknown. Such accurate introspection requires discriminating correct decisions from incorrect ones, a capacity that varies substantially across individuals. We dissociated variation in introspective ability from objective performance in a simple...