Back to the Future: Anticipatory synchronisation as a core mechanism for interarea brain communication

Projektinformationen

BACK2FUTURE

ID Finanzhilfevereinbarung: 101116685

DOI

10.3030/101116685

EK-Unterschriftsdatum 14 November 2023

Startdatum 1 Januar 2024

Enddatum 31 Dezember 2028

Finanziert unter

• European Research Council (ERC)

Gesamtkosten

€ 1 499 750,00

EU-Beitrag

€ 1 499 750,00

Koordiniert durch

UNIVERSITEIT MAASTRICHT
Netherlands

Periodic Reporting for period 1 - BACK2FUTURE (Back to the Future: Anticipatory synchronisation as a core mechanism for interarea brain communication)

Berichtszeitraum: 2024-01-01 bis 2026-06-30

Zusammenfassung vom Kontext und den Gesamtzielen des Projekts

The human brain works through continuous communication between different areas and the external world. Sensory regions process information from the outside world, while frontal brain areas provide context to sensory regions by integrating new information with past knowledge, guiding future behavior. For this communication to be effective, signals must arrive at the right moment, not just carry the right information.

A central challenge is that sensory brain areas need to remain closely connected to incoming information from the environment, while at the same time being influenced by feedback from frontal regions. For this to be possible, frontal brain areas need to anticipate upcoming sensory activity, so that their feedback arrives in time to shape processing rather than reacting too late. How the brain achieves this precise timing remains poorly understood.

The objective of this project is to understand the mechanistic underpinnings of anticipatory communication as well as to externally simulate or amplify such mechanisms using electrical brain stimulation. By focusing on how frontal areas time their feedback to sensory regions, the project aims to provide a new explanation for how different brain areas coordinate their activity efficiently. This work seeks to resolve a long-standing question about the timing of brain communication and to lay the foundation for future applications that rely on precisely timed interaction between brain regions.

Arbeit, die ab Beginn des Projekts bis zum Ende des durch den Bericht erfassten Berichtszeitraums geleistet wurde, und die wichtigsten bis dahin erzielten Ergebnisse

The project has made strong progress in developing and evaluating a new explanation for how different brain areas coordinate their activity over time.

Computational modelling work examined multiple candidate mechanisms for coordination between sensory and frontal brain regions while maintaining sensitivity to external input. This work identified that even though frontal cortex is the main driver for determining the content of information during inter-area communication, anticipation requires that frontal cortex does not drive the neuronal temporal coordination. Modelling work showed that one viable solution allowing such coordination is a connection scheme relying on inhibitory feedback loops in frontal areas, so-called anticipated synchronization. This coordination allows for efficient coordination without disrupting sensory processing. Besides the theoretical implications, the work also identified and developed suitable analytical approaches able to quantify anticipatory communication in the brain. Currently, we are applying these methods to human intracranial EEG data verifying the existence of anticipatory synchronization in the brain.

In parallel, behavioural and neurophysiological experiments were conducted to investigate the role of anticipatory synchronization during sensory processes requiring continuous monitoring and evaluation of incoming input. While some experimental paradigms required refinement, this led to improved designs better suited to studying anticipatory mechanisms in the brain.

The final goal of the project is to use transcranial electrical stimulation to induce anticipatory synchronization by implementing a feedback loop in an online, closed-loop setting. Achieving this requires two key capabilities: (1) the ability to record and analyse EEG data in real time, and (2) reliable removal of stimulation-related artifacts from EEG signals recorded during electrical stimulation. The first objective has been successfully achieved. We implemented a closed-loop EEG framework and used it in an initial study to test whether aligning stimulation or sensory input with specific phases of ongoing brain activity can improve memory performance. The results demonstrate the potential of precisely timed, phase-specific interventions. The second objective is currently underway. A complete combined brain stimulation–EEG dataset has been collected, and we are now verifying whether our newly developed artifact-removal methods enable reliable analysis of EEG data recorded during stimulation.

Fortschritte, die über den aktuellen Stand der Technik hinausgehen und voraussichtliche potenzielle Auswirkungen (einschließlich der bis dato erzielten sozioökonomischen Auswirkungen und weiter gefassten gesellschaftlichen Auswirkungen des Projekts)

The project has delivered important results at both the theoretical and empirical level, advancing understanding of how temporal coordinating between brain areas is achieved. Additionally, several tools are being developed to advance the closed-loop application of electrical brain stimulation.

Computational modelling provided a key result by demonstrating fundamental limitations in existing models of inter-area phase synchronization and identifying anticipatory synchronization as a viable solution for coordinating sensory and frontal brain activity without disrupting sensory processing. This work establishes a theoretical framework that can guide future modelling and experimental studies. Further uptake will benefit from continued integration of these models into empirical research and comparative testing across datasets.

Empirically, the project demonstrated that closed-loop, phase-dependent presentation of sensory information can improve memory performance, highlighting the functional relevance of precise timing in brain processing. This finding motivates further studies to assess robustness across modalities and cognitive domains.

In addition, the project enabled the use of causal analysis strategies in human intracranial EEG data to directly test dynamical systems predictions, representing a methodological advance for studying brain communication. Wider adoption will require further validation and accessible implementation of these methods.

Finally, the project has contributed to a principled framework for interpreting entrainment in transcranial alternating current stimulation and initiated methodological development toward reliable removal of stimulation-related artifacts. These advances are essential for studying and applying closed-loop brain stimulation, and their further development is a key requirement for broader impact.