Towards understanding human consciousness: How internal brain states and environmental context shape our subjective experience

Project Information

HUMANCONSCIOUSNESS

Grant agreement ID: 101044686

DOI

10.3030/101044686

EC signature date 7 December 2022

Start date 1 September 2023

End date 31 August 2028

Funded under

• European Research Council (ERC)

Total cost

€ 1 999 562,50

EU contribution

€ 1 999 562,50

Coordinated by

UNIVERSITEIT VAN AMSTERDAM
Netherlands

Periodic Reporting for period 1 - HUMANCONSCIOUSNESS (Towards understanding human consciousness: How internal brain states and environmental context shape our subjective experience)

Reporting period: 2023-09-01 to 2026-02-28

Summary of the context and overall objectives of the project

Consciousness is subjective experience, ‘what it feels like’ to seeing a beautiful scene, hearing a piece of music or to feel joy or sadness. In the last three decades tremendous progress has been made in identifying the neural correlates of consciousness, mostly at the level of whole brain regions. To further increase our understanding of consciousness however, incorporating new insights into the biochemical and psychological factors that underly conscious experience is crucial. In particular, we need to bring together new insights about the neurotransmitter systems that drive sensory processing, the mechanisms that cause changes in wakefulness and arousal, and how the brain shapes perception by predicting patterns and regularities in the world. In this ERC consolidator project, we do so by combining brain imaging techniques (fMRI and EEG) with measures of bodily signals like pupil size, pharmacological interventions, and computational modeling, all while participants perform novel tasks designed to probe their subjective perceptual experiences.

This project has three main aims, tackled in three separate work packages. I will first test the hypothesis that excitatory (NMDA-mediated) and inhibitory (GABAergic) neurotransmitter systems play central, albeit different roles in recurrent neural processes, crucial for conscious experience. Second, I will test how subjective experience is shaped by spontaneous fluctuations in arousal and levels of physical activity of the body. Third, I will test how conscious experience is modulated by the interplay between predictions and sensory input. This research promises to provide an integrative framework for understanding the neural and biochemical mechanisms of consciousness, and will reveal how it is shaped and determined by being a human agenhttps://ec.europa.eu/research/participants/grants-app/reporting/VAADIN/themes/sygma/icons/arrowOff.pngt that interacts with and predicts its environment.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The first two years of this ERC Consolidator project have been highly productive. An excellent, well-coordinated team has been assembled, enabling strong progress across all three work packages (WPs).

WP1 investigates the neural and chemical mechanisms of conscious experience. Despite a slight start-up delay, participant recruitment is underway. Studies by PhD students focus on how GABAergic modulation and expectations shape feedforward and feedback processing using pharmacology (Lorazepam), EEG, fMRI, and pupil-linked arousal measures.

WP2 examines how fluctuations in brain states (arousal) influence conscious experience. Several large datasets have been collected, and are currently analyzed, exploring the effects of sleep deprivation, task difficulty, and active versus passive states on perception and neural processing. Initial findings already show that pupil-linked arousal affects feedback but not feedforward activity. We have also developed new methodologies, including a novel analysis protocol that separates pupil-linked arousal into long-, medium-, and short-term arousal fluctuations, rather than treating them as a single measure. Additional theoretical work is underway to clarify assumptions about pupil size as a marker of neuromodulatory activity.

WP3 explores the interplay between predictions and conscious experience. An initial study has been completed, and follow-up studies are planned to further understand how different types of predictions shape conscious perception.

Overall, despite the complexity of the studies, substantial phttps://ec.europa.eu/research/participants/grants-app/reporting/VAADIN/themes/sygma/icons/arrowOff.pngrogress has been made in data collection, method development, and theoretical integration.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

As the project is still in its early stages, having been underway for only two years, it is too soon to report results that go beyond the current state-of-the-art. Instead, the focus so far has been on establishing the team, developing novel methodologies, collecting several high-quality datasets, and laying the groundwork for the analyses and discoveries that the project is designed to achieve.