Brain Networks Involved in Inner World Control (INNERWORLD)

Brain Networks Involved in the Cognitive Control of Inner Langage and Self Representation.

Inner speech (the "little voice" in our heads) plays a central role in our ability to perform complex cognitive tasks such as problem solving, reading, writing, thinking, and self awareness. It is estimated that at least a quarter of our lives is accompanied by inner speech, whether deliberate (mentally making a list) or more spontaneous (mind wandering). Although central to human life, its neural bases remain poorly understood. It has been recently discovered a single region in the human prefrontal cortex absent in nonhuman primates, the prefrontal operculum (PFO), which shows a pattern of functional connectivity with the rest of the brain that could give it a role in controlling inner speech. The aim of this research is to understand how the brain generates and controls inner speech using functional magnetic resonance imaging (fMRI). Dysfunctions of inner speech, especially when spontaneous and wandering, can lead to severe mental disorders (anxiety disorders, depression, verbal auditory hallucinations). It is therefore crucial to identify the role of the PFO and the networks that involve it, particularly the precuneus, in controlling inner speech across its different manifestations. The first hypothesis is that the PFO and the networks that include it play a key role in the cognitive control of inner speech in participants who experience inner speech. The second hypothesis is that the PFO is hyperactive in participants who lack inner speech (so called aphantasics), preventing the production of inner speech. To test these hypotheses, participants will complete a battery of well established questionnaires to determine whether they can produce inner speech (control participants with typical inner speech) or not (aphantasic participants). These participants will take part in an fMRI study contrasting tasks that recruit inner speech that do or do not require cognitive control. The third hypothesis is that the extent of inner speech depends on the capacity for self representation, and thus on the interaction between the PFO and the precuneus. The investigator hypothesize a positive correlation between inner speech ability and self representation capacity, associated with stronger functional connectivity between the PFO and the precuneus. The investigator predict reduced self representation in aphantasic participants. To test this, participants will complete a battery of well established questionnaires. The investigator will compute correlations between 1) behavioral performance on inner speech tasks and questionnaire scores, and 2) the network measures identified in fMRI (task activation and connectivity) and questionnaire scores.

Study Overview

• Status: Not yet recruiting
• Conditions: Neurosciences
• Intervention / Treatment: Behavioral: Neuropsychological evaluation, questionnaires, and training on the tasks that will be performed in the MRI.; Other: MRI visits

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Fadila Hadj-Bouziane; Phone Number: 04 72 91 34 04; Email: fadila.hadj-bouziane@inserm.fr

Study Locations

• France
  • Bron, France
    • CRNL, IMPACT team, INSERM U1028
    • Contact: Fadila Hadj-Bouziane; Phone Number: 04 72 91 34 04; Email: fadila.hadj-bouziane@inserm.fr
    • Principal Investigator: Fadila Hadj-Bouziane
  • Bron, France
    • Plateforme PRIMAGE, Cermep
    • Contact: Fadila Hadj-Bouziane; Phone Number: 04 72 91 34 04; Email: fadila.hadj-bouziane@inserm.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Registered with the national Social Security system.
• Right handed.
• Native French speakers.
• Visual acuity sufficient to read stimuli (contact lenses permitted).
• Willing to follow MRI instructions and recommendations.
• Able to provide written informed consent to participate in the study.

Exclusion Criteria:

• History of known neurological or psychiatric disorder.

  • Respiratory pathologies (in particular persistent asthma) or cardiovascular diseases.
  • Speech or language disorders (aphasia, dysphasia, dysarthria, stuttering, etc.).
  • Hearing impairments.
  • Memory disorders.
  • Cognitive impairments limiting understanding of instructions.

  • Recent use of psychotropic medications. Major treatments not permitted in this research include psychotropic drugs that can alter perception, sensations, mood, consciousness, or behavior, for example:

    • Antipsychotics (valproic acid, amisulpride, aripiprazole, clozapine, cyamemazine, haloperidol, loxapine, olanzapine, risperidone).
    • Antidepressants (amitriptyline, citalopram, clomipramine, duloxetine, escitalopram, fluoxetine, mianserin, mirtazapine, nortriptyline, paroxetine, sertraline, venlafaxine).
    • Anxiolytics.
  • Pregnant or breastfeeding women. No pregnancy test will be performed at inclusion; pregnancy must be reported by self declaration.
  • Minors.
  • Persons deprived of liberty by judicial or administrative decision.
  • Persons admitted to a health or social institution for reasons other than research.
  • Adults under legal protection measures (guardianship, conservatorship).
  • Persons not affiliated with a social security scheme or with a similar scheme only.
  • Participants refusing to be informed in case of an incidental finding on MRI.

  • Contraindications to fMRI, including:

    • Pacemaker, neurosensory stimulator, or implantable defibrillator: risk of transient or permanent device damage or heating of metal parts. In patients with such devices, scanning should be performed only if absolutely necessary, with the patient's informed agreement after clear explanation of risks, and in the presence of a physician from the referring service.
    • Metallic prostheses: potential for significant artifacts depending on size and ferromagnetic properties; certain neurosurgical clips or cardiac valves may pose problems and require verification of the exact implanted model.
    • Ferromagnetic ocular or intracranial foreign bodies near nervous structures: risk of displacement and ocular or cerebral injury.
    • Cochlear implants: risk of demagnetization, electrode heating, and artifacts.
    • Neurosurgical shunt valves.
    • Claustrophobic participants.
    • Dental appliances.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Neurotypical subjects; The study population will consist of healthy adult human participants, male and female, with inner speech, whose native language is French	Behavioral: Neuropsychological evaluation, questionnaires, and training on the tasks that will be performed in the MRI.; The neuropsychological/questionnaires evaluation is a 3 hour visit during which participants will complete a battery of neuropsychological tests and respond to questionnaires assessing their capacity for inner speech and self representation. In a second 30 minute visit, they will be trained on the tasks (inner speech tasks and control tasks) that they will perform in the MRI.; Other: MRI visits; There will be two 2 hour MRI visits. During the first visit, participants will perform the learned task conditions designed to test the control of inner speech; during the second visit, they will perform the control conditions and an anatomical MRI will be acquired, as well as a resting state fMRI scan to study functional connectivity and a DTI scan to study structural connectivity
Experimental: Aphantasic subjects; The study population will consist of healthy adult human participants, male and female, without inner speech, whose native language is French	Behavioral: Neuropsychological evaluation, questionnaires, and training on the tasks that will be performed in the MRI.; The neuropsychological/questionnaires evaluation is a 3 hour visit during which participants will complete a battery of neuropsychological tests and respond to questionnaires assessing their capacity for inner speech and self representation. In a second 30 minute visit, they will be trained on the tasks (inner speech tasks and control tasks) that they will perform in the MRI.; Other: MRI visits; There will be two 2 hour MRI visits. During the first visit, participants will perform the learned task conditions designed to test the control of inner speech; during the second visit, they will perform the control conditions and an anatomical MRI will be acquired, as well as a resting state fMRI scan to study functional connectivity and a DTI scan to study structural connectivity

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To assess the role of the prefrontal operculum (PFO) (and the brain network to which it belongs)	MRI measurement (without contrast injection) according to the conditions of inner speech used	at 60 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To assess the relation between MRI and behavioral measures - behavioral performance	MRI (task activation and functional connectivity) and diffusion tensor imaging DTI (structural connectivity) in correlation with behavioral performance on inner speech tasks. The unit of the behavioral performance is the percent correct	during 60 days
To assess the relation between MRI and behavioral measures - inner speech	MRI (task activation and functional connectivity) and diffusion tensor imaging DTI (structural connectivity) in correlation with scores on inner speech and self perception questionnaires specific to each participant (unit reflecting the participants' profile).	during 60 days

Collaborators and Investigators

• Sponsor: Hospices Civils de Lyon

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): May 1, 2028
• Study Completion (Estimated): May 1, 2028

Study Registration Dates

• First Submitted: February 24, 2026
• First Submitted That Met QC Criteria: March 10, 2026
• First Posted (Actual): March 13, 2026

Study Record Updates

• Last Update Posted (Actual): March 13, 2026
• Last Update Submitted That Met QC Criteria: March 10, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: imaging; self; precuneus; Prefrontal operculum; inner language
• Additional Relevant MeSH Terms: Health Care Quality, Access, and Evaluation; Investigative Techniques; Epidemiologic Methods; Data Collection; Health Care Evaluation Mechanisms; Quality of Health Care; Public Health; Environment and Public Health; Surveys and Questionnaires
• Other Study ID Numbers: 69HCL25_0796

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No