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...
Elife
June 18, 2025
Samuel Noorman, Timo Stein, Jasper B. Zantvoord et al.
2 citations
Perceptual inference requires the integration of visual features through recurrent processing, the dynamic exchange of information between higher- and lower-level cortical regions. While animal research has demonstrated a crucial role of NMDA receptors in recurrent processing, establishing a causal link between NMDA receptors and recurrent processing in humans has remained challenging. Here, we...
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...
September 26, 2023
Timo Stein, Simon van Gaal, Johannes J Fahrenfort
preprint
The standard scientific approach to studying consciousness involves contrasting conscious operations with unconscious ones. However, challenges in establishing the absence of conscious awareness have led to debates about the extent and existence of unconscious processes. We collected experimental data on unconscious semantic priming, manipulating prime presentation duration to highlight the...
Perspectives on Psychological Science
May 2023
Matan Mazor, Simon Brown, Anna Ciaunica et al.
A target question for the scientific study of consciousness is how dimensions of consciousness, such as the ability to feel pain and pleasure or reflect on one's own experience, vary in different states and animal species. Considering the tight link between consciousness and moral status, answers to these questions have implications for law and ethics. Here we point out that given this link,...
PLoS Biology
May 1, 2021
Timo Stein, Daniel Kaiser, Johannes J Fahrenfort et al.
The study of unconscious processing requires a measure of conscious awareness. Awareness measures can be either subjective (based on participant's report) or objective (based on perceptual performance). The preferred awareness measure depends on the theoretical position about consciousness and may influence conclusions about the extent of unconscious processing and about the neural correlates...
Cognitive Neuroscience
2021
Johannes J Fahrenfort, Simon van Gaal
10 citations
Doerig and colleagues put forward the notion that we need hard and theory-neutral criteria by which to arbitrate between empirical (mechanistic) theories of consciousness. However, most of the criteria that they propose are not theory neutral because they focus on functional equivalence between systems. Because empirical theories of consciousness are mechanistic rather than functionalist, we...
bioRxiv
November 11, 2020
Timo Stein, Daniel Kaiser, Johannes J Fahrenfort et al.
preprint
The study of unconscious processing requires a measure of conscious awareness. Awareness measures can be either subjective (based on participant’s report) or objective (based on perceptual performance). The preferred awareness measure depends on the theoretical position about consciousness, and may influence conclusions about the extent of unconscious processing and about the neural correlates...
eNeuro
2019
Matthew D Weaver, Johannes J Fahrenfort, Artem Belopolsky et al.
Several influential theories of consciousness attempt to explain how, when and where conscious perception arises in the brain. The extent of conscious perception of a stimulus is often probed by asking subjects to provide confidence estimations in their choices in challenging perceptual decision-making tasks. Here, we aimed to dissociate neural patterns of "cognitive" and "sensory" information...
Proceedings of the National Academy of Sciences
April 4, 2017
Johannes J Fahrenfort, Jonathan Van Leeuwen, Christian N L Olivers et al.
102 citations
The visual system has the remarkable ability to integrate fragmentary visual input into a perceptually organized collection of surfaces and objects, a process we refer to as perceptual integration. Despite a long tradition of perception research, it is not known whether access to consciousness is required to complete perceptual integration. To investigate this question, we manipulated access to...