Tracking Inner Experiences: Neuronal and Behavioral Perspectives in Conscious Neurotypical Participants.
| Registry | NCT07885020, acronym NEURO-IS |
|---|---|
| Status | Recruiting |
| Phase | Not applicable |
| Study type | Interventional; na, single group, masking: none, basic science |
| Enrollment | 35 (Estimated) |
| Sponsor | University of Liege (Other) |
| Conditions | Healthy Volunteer, Inner Speech, Visual Mental Imagery |
| Interventions | Inner Experience Induction Tasks and hdEEG (Behavioral) |
| Dates | start 2026-10-05 (estimated), primary completion 2027-10-31 (estimated), completion 2027-10-31 (estimated), first posted 2026-10-21, last updated 2026-10-21 |
| Locations | 1 site in Belgium |
Related Papers Related Patents Related Grants Related Experts
All trials for Healthy Volunteer All trials for Inner Speech All trials of Inner Experience Induction Tasks and hdEEG
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.
Background and scientific rationale :
The most frequently reported subjective experiences in the general population are visual mental imagery (VMI) and inner speech (IS). VMI refers to the ability to mentally "see" objects or actions in their physical absence, while IS is defined as the subjective experience of language without overt articulation. IS presents several phenomenological aspects, such as condensation, evaluative aspects, dialogic properties, and the involvement of others. It has been associated with high-level consciousness, self-reflection, and metacognition. Previous studies have identified EEG biomarkers reflecting the induction of both IS (e.g., N400, theta, beta, and gamma bands) and VMI (e.g., alpha band desynchronization, anterior negativity). The primary objective of this study is to determine which neurophysiological biomarkers resulting from the induction of these inner experience tasks are the most robust.
Study hypotheses :
The research is driven by three main hypotheses:
1. Mentally reciting a word will provide robust EEG biomarkers of IS (stable modulations in the beta and gamma bands), particularly in comparison with the passive listening of that same word.
2. A lower reflective consciousness will be associated with an overall reduction in the use of IS.
3. The condensation dimension of IS will be negatively correlated with reflective consciousness, whereas the dialogic dimension will be positively associated with levels of reflective consciousness.
General experimental plan :
The study will enroll neurotypical conscious adult participants. The experimental session involves both behavioral and neurophysiological assessments. First, participants will complete validated questionnaires evaluating self-consciousness and inner experiences, including the Short French Meta-Cognitions Questionnaire (MCQ-30), the Rumination-Reflection Questionnaire (RRQ), the Varieties of Inner Speech Questionnaire-Revised (VISQ-R), and the Vividness of Visual Imagery Questionnaire (VVIQ).
Following a training phase, participants will undergo high-density electroencephalography (hdEEG) recording during resting state and experimental tasks. The paradigms consist of four mental imagery conditions:
* IS (auditory presentation): Mentally repeating a word heard orally.
* IS (visual presentation): Mentally repeating a written word presented on a screen.
* VMI (hand movement): Mentally visualizing opening and closing the right hand.
* VMI (face imagery): Mentally visualizing a face. These tasks are designed to isolate specific cognitive constraints, with strictly controlled trials composed of a stimulus presentation followed by an action phase. A 5 minute passive listening period of an audio story comprising the target words will serve as a control condition to capture baseline electrophysiological activity during passive semantic processing.
After each main task block, participants will retrospectively evaluate their subjective experiences using visual analog scales (VAS) to assess task success, modality used, generated content, perceived difficulty, and modality mixing.
Data analyses will investigate behavioral measures and neurophysiological signatures (such as beta and gamma bands for IS, and alpha band for VMI) using standard statistical approaches. In an exploratory approach, a deep learning model based on a Convolutional Neural Network (CNN) will also be tested to classify EEG signals reflecting IS or VMI.
Clinical perspectives :
The investigation of these inner experiences and their biomarkers opens long-term clinical applications. For patients with aphasia, these tools could help determine if IS is preserved despite the loss of overt speech, and explore its potential impact on anosognosia. Additionally, for patients with disorders of consciousness, these neurophysiological tools could offer the opportunity to investigate "hidden cognition", ultimately contributing to reducing clinical diagnostic errors.
| Arm | Type | Interventions | Description |
|---|---|---|---|
| Healthy Volunteers | Experimental | Behavioral: Inner Experience Induction Tasks and hdEEG | 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. |
Sex: All, ages: 18 Years to 70 Years, accepts healthy volunteers
Inclusion Criteria: * Be aged 18 to 70. * Have French as a native language. Exclusion Criteria: * Presence of a neurological or psychiatric disorder. * Presence of an uncorrected sensory deficit. * Use of medications acting on the central nervous system.
| Facility | City | Country | Status |
|---|---|---|---|
| Université de Liège - GIGA Institute (Coma Science Group) | Liège, Wallonia | Belgium | Recruiting |