NEURO-IS: Neurophysiology of Inner Speech Across Neurotypical Participants.

NCT07885020 | Recruiting

• 3 other identifiers: 2026-429B7072026000097CE2026-429
• Study Type: interventional
• Target: 35
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to investigate the brain activity associated with two common inner experiences: visual mental imagery (mentally seeing objects or actions) and inner speech (experiencing language without speaking out loud). Researchers aim to identify the most effective tasks to generate robust and detectable brain signals (EEG biomarkers) for these experiences in healthy adults. Participants will complete questionnaires and perform specific mental tasks, such as silently repeating words or imagining movements and faces, while their brain activity is recorded using high-density electroencephalography (hdEEG). These tasks will be compared to resting and passive listening conditions to better understand the relationship between inner experiences, self-awareness, and neurophysiology.

Conditions

Healthy Volunteer; Inner Speech; Visual Mental Imagery

Keywords

Inner Speech; Visual Mental Imagery; Electroencephalography; Metacognition; Inner Experiences

Outcome Measures

Primary Outcomes (1)

• Modulation of EEG spectral power (Alpha, Beta, and Gamma bands)

  The primary evaluation relies on the analysis of high-density EEG signals in response to the induction of inner experiences. Specifically, the analysis will focus on identifying the most robust paradigms by examining specific EEG characteristics: modulation in the beta and gamma frequency bands for Inner Speech (IS), and alpha band desynchronization for Visual Mental Imagery (VMI). The goal is to identify the most appropriate and effective tasks to generate these detectable biomarkers.

  Day 1

Secondary Outcomes (2)

• Difference in EEG biomarkers between passive listening and active mental repetition

  Day 1

• Correlation between self-consciousness scores and phenomenological dimensions of inner speech

  Day 1

Study Arms (1)

Healthy Volunteers

EXPERIMENTAL

Participants undergo a single experimental session. They first complete behavioral questionnaires evaluating self-consciousness and inner experiences (MCQ-30, RRQ, VISQ-R, VVIQ). Following a training phase, their brain activity is recorded using high-density electroencephalography (hdEEG). During the EEG recording, they perform cognitive tasks designed to induce inner speech (auditory and visual presentation of words) and visual mental imagery (imagining hand movements and familiar faces). Resting state and passive listening conditions are also recorded as baselines. Finally, they evaluate their subjective experience using visual analog scales.

Behavioral: Inner Experience Induction Tasks and hdEEG

Interventions

Inner Experience Induction Tasks and hdEEG BEHAVIORAL

The intervention consists of performing specific mental tasks to induce inner speech (mentally repeating heard or read words) and visual mental imagery (mentally visualizing a hand movement or a loved one's face). These tasks are performed while high-density EEG (hdEEG) is recorded. The protocol also includes a resting state period, a passive listening control condition, and the completion of psychological questionnaires (MCQ-30, RRQ, VISQ-R, VVIQ).

Healthy Volunteers

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Be aged 18 to 70.
• Have French as a native language.

You may not qualify if:

• Presence of a neurological or psychiatric disorder.
• Presence of an uncorrected sensory deficit.
• Use of medications acting on the central nervous system.

Sponsors & Collaborators

• University of Liege: lead

Study Sites (1)

Université de Liège - GIGA Institute (Coma Science Group)

Liège, Wallonia, 4020, Belgium

RECRUITING

Related Publications (26)

• Whitford TJ, Spencer KM, Godwin M, Hirano Y, Chung LK, Vodovozov W, Griffiths O, Harris AWF, Le Pelley ME, Jack BN. Gamma and Theta/Alpha-Band Oscillations in the Electroencephalogram Distinguish the Content of Inner Speech. eNeuro. 2025 Feb 10;12(2):ENEURO.0297-24.2025. doi: 10.1523/ENEURO.0297-24.2025. Print 2025 Feb.

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• Stephan F, Saalbach H, Rossi S. The Brain Differentially Prepares Inner and Overt Speech Production: Electrophysiological and Vascular Evidence. Brain Sci. 2020 Mar 4;10(3):148. doi: 10.3390/brainsci10030148.

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• Fama ME, Turkeltaub PE. Inner Speech in Aphasia: Current Evidence, Clinical Implications, and Future Directions. Am J Speech Lang Pathol. 2020 Feb 21;29(1S):560-573. doi: 10.1044/2019_AJSLP-CAC48-18-0212. Epub 2019 Sep 13.

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• Villena-Gonzalez M, Palacios-Garcia I, Rodriguez E, Lopez V. Beta Oscillations Distinguish Between Two Forms of Mental Imagery While Gamma and Theta Activity Reflects Auditory Attention. Front Hum Neurosci. 2018 Sep 25;12:389. doi: 10.3389/fnhum.2018.00389. eCollection 2018.

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• Pratts J, Pobric G, Yao B. Bridging phenomenology and neural mechanisms of inner speech: ALE meta-analysis on egocentricity and spontaneity in a dual-mechanistic framework. Neuroimage. 2023 Nov 15;282:120399. doi: 10.1016/j.neuroimage.2023.120399. Epub 2023 Oct 11.

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• Lee SH, Lee M, Lee SW. Neural Decoding of Imagined Speech and Visual Imagery as Intuitive Paradigms for BCI Communication. IEEE Trans Neural Syst Rehabil Eng. 2020 Dec;28(12):2647-2659. doi: 10.1109/TNSRE.2020.3040289. Epub 2021 Jan 28.

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• Langland-Hassan P, Gauker C, Richardson MJ, Dietz A, Faries FR. Metacognitive deficits in categorization tasks in a population with impaired inner speech. Acta Psychol (Amst). 2017 Nov;181:62-74. doi: 10.1016/j.actpsy.2017.10.004. Epub 2017 Oct 25.

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• Jack BN, Le Pelley ME, Han N, Harris AWF, Spencer KM, Whitford TJ. Inner speech is accompanied by a temporally-precise and content-specific corollary discharge. Neuroimage. 2019 Sep;198:170-180. doi: 10.1016/j.neuroimage.2019.04.038. Epub 2019 Apr 16.

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• Delamillieure P, Doucet G, Mazoyer B, Turbelin MR, Delcroix N, Mellet E, Zago L, Crivello F, Petit L, Tzourio-Mazoyer N, Joliot M. The resting state questionnaire: An introspective questionnaire for evaluation of inner experience during the conscious resting state. Brain Res Bull. 2010 Apr 5;81(6):565-73. doi: 10.1016/j.brainresbull.2009.11.014. Epub 2009 Dec 7.

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• Chung LK, Jack BN, Griffiths O, Pearson D, Luque D, Harris AWF, Spencer KM, Le Pelley ME, So SH, Whitford TJ. Neurophysiological evidence of motor preparation in inner speech and the effect of content predictability. Cereb Cortex. 2023 Dec 9;33(24):11556-11569. doi: 10.1093/cercor/bhad389.

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• Alderson-Day B, Mitrenga K, Wilkinson S, McCarthy-Jones S, Fernyhough C. The varieties of inner speech questionnaire - Revised (VISQ-R): Replicating and refining links between inner speech and psychopathology. Conscious Cogn. 2018 Oct;65:48-58. doi: 10.1016/j.concog.2018.07.001. Epub 2018 Jul 13.

  PMID: 30041067 BACKGROUND

Study Officials

• Olivia Gosseries, PhD

  University of Liege

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Olivia Gosseries, PhD

CONTACT

+32 4 323 36 14; ogosseries@uliege.be

Anaïs Gillet, Master

CONTACT

+32 4 323 36 14; agillet@uliege.be

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Dr. Olivia Gosseries

Study Record Dates

• First Submitted: October 13, 2026
• First Posted: October 21, 2026
• Study Start: October 5, 2026
• Primary Completion (Estimated): October 31, 2027
• Study Completion (Estimated): October 31, 2027
• Last Updated: October 21, 2026

Record last verified: 2026-10

Locations

BE (1)