Externalization and Stimulation

NCT05936307 | Unknown DMC

• 1 other identifier: 2023-A00452-43
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The distinction between self-generated and external information is impaired in patients with schizophrenia, who are assumed to confuse imagination with real perceptions. To better understand the underlying mechanisms of these abnormalities, the investigator will investigate the brain mechanisms supporting auditory externalization. Auditory externalization is the ability to perceive whether a sound comes from inside or outside oneself. Our study, in healthy participants, will use functional brain imaging to identify the brain areas involved in the externalization of sound sources and to test whether neuromodulation of this area can modify this ability and provide a therapeutic lead in pathological populations

Conditions

Healthy Participants

Keywords

externalization; auditory processing; reality-monitoring; stimulation; HD-TDCS

Outcome Measures

Primary Outcomes (1)

• Externalization abilities

  proportion of sounds perceived as coming from an external source in the externalization task (range 0-100%)

  one year

Secondary Outcomes (6)

• Reality monitoring performance

  one year

• Self-agency

  one year

• Psychometric characteristics that may influence externalization abilities and stimulation effects

  baseline

• Psychometric characteristics that may influence externalization abilities and stimulation effects

  baseline

• Side effects of stimulation

  1 time before (baseline) and within 1 hour after stimulation

Study Arms (2)

15 healthy participants active then placebo

ACTIVE COMPARATOR

15 healthy participants will receive a session of active HD-tDCS and then a session of placebo HD-tDCS.

Procedure: High-definition transcranial direct current (HD-tDCS), active condition; Procedure: High-definition transcranial direct current (HD-tDCS), placebo condition

15 healthy participants placebo then active

PLACEBO COMPARATOR

15 healthy participants will receive a session of placebo HD-tDCS and then a session of active HD-tDCS.

Procedure: High-definition transcranial direct current (HD-tDCS), active condition; Procedure: High-definition transcranial direct current (HD-tDCS), placebo condition

Interventions

High-definition transcranial direct current (HD-tDCS), active condition PROCEDURE

Participants will receive a session of active HD-tDCS at a current intensity of 2 mA for a duration of 25min. The placement of electrodes will be determined to specifically target the brain area that has been identified as being involved in the process of externalization, as evidenced by fMRI. During the stimulation, participants will be engaged in a computer-based externalization task.

15 healthy participants active then placebo; 15 healthy participants placebo then active

High-definition transcranial direct current (HD-tDCS), placebo condition PROCEDURE

Participants will receive a session of placebo HD-tDCS, which will be delivered following the same procedures as active HD-tDCS but the intensity of the current will be set at 2mA during the 30 first seconds at the beginning of the 25-min period of the stimulation, and equal to 0 mA for the reminding period of stimulation to simulate the tingling sensation often experienced by individuals during active stimulation. The placement of electrodes will be determined to specifically target the brain area that has been identified as being involved in the process of externalization, as evidenced by fMRI. During the stimulation, participants will be engaged in a computer-based externalization task

15 healthy participants active then placebo; 15 healthy participants placebo then active

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Having given their written informed consent
• Affiliated with a social security scheme
• French speakers and readers

You may not qualify if:

• With contraindication to HD-tDCS stimulation or fMRI
• With a history of or current hearing problems, including tinnitus
• Taking medication (except contraceptives)
• With a history of or current psychiatric diagnosis (DSM-5 criteria)
• First-degree relatives with a diagnosis of schizophrenia spectrum disorder or bipolar disorder (DSM5)
• Have a personal history of neurological disorders or head trauma with loss of consciousness
• With an intellectual disability (Raven's Matrices)
• With developed musical abilities (i.e., regular practice of a musical instrument for at least 10 years with assiduity or at a music school or conservatory)
• Pregnant or nursing
• Under guardianship

Sponsors & Collaborators

• Hôpital le Vinatier: lead

Study Sites (1)

Centre Hospitalier le Vinatier

Bron, 69678, France

RECRUITING

Study Officials

• Marine MONDINO, Phd

  hospital le Vinatier

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Marine MONDINO, PhD

CONTACT

0437915565; marine.mondino@ch-le-vinatier.fr

Lydie SARTELET

CONTACT

0437915531; lydie.sartelet@ch-le-vinatier.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Participants and experimenters (including tDCS operator) will not be informed about the nature (active or placebo) of the stimulation they will receive.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Double-blind, placebo-controlled, randomized crossover study including 30 healthy participants who will receive active and placebo HD-tDCS in a counterbalanced order.

Study Record Dates

• First Submitted: June 16, 2023
• First Posted: July 7, 2023
• Study Start: January 16, 2024
• Primary Completion: January 16, 2025
• Study Completion: September 30, 2025
• Last Updated: March 7, 2024

Record last verified: 2023-06

Locations

FR (1)