Understanding the Neural Dynamics of Inner Speech: A Multimodal and Longitudinal Perspective

This project bridges research in BCI, neuroimaging, and machine learning, addressing the critical challenge of decoding complex and abstract thought processes, such as inner speech. While prior studies have translated brain activity into simple commands by recognizing patterns linked to specific movements, decoding inner speech remains a largely unresolved problem.

Amyotrophic lateral sclerosis (ALS), the most common type of motor neuron disease (MND) accounting for approximately 90% of the cases, is a progressive neurodegenerative disorder characterized by the loss of motor neurons, leading to muscle weakness and eventual respiratory failure. In Sweden, the incidence of ALS has risen in recent decades, now surpassing 4 cases per 100,000 person-years, higher than the European average of approximately 2.0–2.31 per 100,000 person-years . This increase may be partially attributed to aging populations and improved diagnostic accuracy, but other genetic and environmental factors are likely involved. Locked-in syndrome (LIS) resulting from late-stage ALS is characterised by loss of motor function and eventually of eye movements , which results in completely loss of communication with traditional non-invasive brain-computer interfaces (BCIs) methods that rely on eye movements. This project aims to develop advanced methods for decoding inner speech, directly interpret neural signals associated with thought. These innovations could significantly enhance communication for LIS individuals, aligning with Sweden’s goals of advancing innovation, equality, and accessibility. The primary objective of the project is to study the neural mechanisms of inner speech by combining electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). As the first to collect multimodal EEG-fMRI data for inner speech, this project aims to establish Sweden as a leader in this emerging research area.

Project duration: 2025-2027

Funded by

• Kempestiftelserna External link.

Project leader

• Foteini Simistira Liwicki

Extrernal collaborators

• Johan Eriksson External link., Professor at Umeå University, UFBI group memebr, cognitive neursoscience and fMRI specialist
• Caroline Ingre External link., Associate Professor and Research Group Leader of the ALS Center at the Department of Clinical Neuroscience at Karolinska Institutet, Sweden
• Spiridoula Stamouli External link., Specialized scientific personnel at the Institute for Language and Speech Processing - Language Technology Expert, Ph.D. in Linguistics
• Vassilis Katsouros External link., Director of the Institute for Language and Speech Processing at Athena Research Center, Greece
• Fotios Tsimpoukas External link., ICU director at General Hopsital of Lamia, Greece

References

1. Chourpiliadis, Charilaos, et al. "Association between cardiometabolic diseases and the risk and progression of motor neuron diseases in Sweden: a population-based case–control study." The Lancet Regional Health–Europe 49 (2025).
2. Imrell, Sofia, et al. "Increased incidence of motor neuron disease in Sweden: a population-based study during 2002– 2021." Journal of Neurology 271.5 (2024): 2730-2735.
3. Zilio, Federico, et al. "Altered brain dynamics index levels of arousal in complete locked-in syndrome." Communications Biology 6.1 (2023): 757.