Understanding how the brain gives rise to conscious experience is one of the central scientific challenges. While modern neuroscience has revealed many of the mechanisms that allow us to detect and respond to sensory information, it remains unclear how and when these neural processes become part of our subjective experience: what we consciously see, feel, or perceive. This question is not only of fundamental scientific interest. It also has practical implications for conditions such as epilepsy, Parkinson’s disease, psychiatric disorders involving hallucinations, and states in which patients are unresponsive or unable to communicate. In these contexts, we urgently need objective, mechanistic markers of conscious experience that do not depend solely on verbal reports.
The project addresses this gap by focusing on a central idea: conscious perception may emerge from a gradual accumulation of sensory evidence in the brain. This “leaky evidence accumulation process” (LEAP) offers a biologically plausible explanation for how a fleeting stimulus becomes a stable conscious experience, how long this experience lasts, and why subjective reports can differ even when sensory input is identical. To investigate this mechanism, the project brings together computational modelling, cognitive psychology, and human intracranial electrophysiology. Its overall objectives are:
WP1: To develop and validate a mechanistic model of conscious perception based on leaky evidence accumulation, using both theoretical and biologically grounded simulations.
WP2: To test the model’s predictions in humans, using rare intracranial recordings that capture activity from local populations of neurons and, in some cases, single neurons within carefully selected brain regions.
WP3: To develop causal tests using direct electrical stimulation.
WP4: To generalise this mechanism to explain false perceptions such as hallucinations in Parkinson's disease, providing insights relevant for both basic science and clinical applications.
Together, these goals aim to establish a new mechanistic framework for studying consciousness—one that links conscious experience to specific patterns of neural population activity. By integrating computational and experimental approaches, the project seeks to move the field beyond descriptive correlations and toward testable explanations of how conscious experiences arise and unfold over time. The expected impact is twofold. Scientifically, the project proposes a unifying account of subjective perception that explains multiple types of subjective reports (detection, confidence, duration) and generalises across tasks. Clinically, the work lays the foundation for better understanding hallucinations and related symptoms. Overall, the project aims to shift consciousness research toward mechanistic, model-based, and clinically grounded approaches, providing new tools and conceptual advances that can benefit both fundamental neuroscience and medicine.
