Special Seminar February 2026

Sleeping while awake: How sleep-like intrusions within wakefulness shape the stream of consciousness

Abstract: Understanding how the brain sustains conscious experience during wakefulness remains a central challenge in neuroscience. Contrary to the classical view of wake as a stable, globally coherent state, accumulating evidence shows that wakefulness is intrinsically heterogeneous and dynamically fragile. In this talk, I will focus on research demonstrating that sleep-like dynamics can emerge locally within the awake brain, giving rise to transient lapses in attention, and subjective awareness. I will show in particular how local sleep-like slow waves during wakefulness reflect a fine-grained regulation of cortical activity, shaped by prior use, neuromodulatory changes, and ongoing cognitive demands. These local intrusions of sleep into wakefulness have measurable behavioural consequences, from attentional lapses to altered perceptual processing, and provide a powerful framework to dissociate conscious state (the capacity for experience) from conscious content (what is experienced at a given moment). I will also present how this framework allows to explore inter-individual differences in attention and the dynamics of conscious experience, and provides new tools and insights into clinical populations such as individuals with attentional disorders (ADHD), hypersomnolence or neuredegenerative diseases. Indeed, beyond lapses of attention and mind wandering, sleep intrusions in wakefulness could also account for episodes of mind blanking or hallucinations. By examining wakefulness through the lens of local sleep, this work reframes consciousness as an emergent and continuously property of distributed neural systems, rather than an all-or-none global state. This perspective offers new insights into everyday cognitive failures as well as clinical conditions marked by impaired vigilance, positioning local sleep during wake as a key mechanism for probing how brain activity shapes conscious experience.

Bio: Thomas Andrillon is a neuroscientist at INSERM (French NHMRC) and the Paris Brain institute (Sleep, Dream and Cognition team aka DreamTeam). He obtained his PhD in 2016 from the Ecole Normale Supérieure in Paris. Dr Andrillon moved to Australia for a postdoc at UNSW in the team of Prof Joel Pearson and then at Monash University in the lab of Prof Nao Tsuchiya. In 2018 he obtained a fellowship from NHMRC and became a Research Fellow at Monash University. He relocated in 2021 at the Paris Brain Institute. Since 2024, he is Co-Editor-in-Chief of Neuroscience of Consciousness, the journal of the Association for the Scientific Study of Consciousness (ASSC). Dr Andrillon researches how fluctuations of brain activity across wakefulness and sleep shape cognitive processes and the stream of consciousness in healthy and clinical populations.

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