REALITY MONITORING

NCT ID: NCT05711082

Last Updated: 2025-03-06

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 39 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-01-15
• Study Completion Date: 2026-12-31

Brief Summary

Reality-monitoring characterizes the ability to determine whether information was perceived in the environment or only imagined . Impaired reality-monitoring abilities have been associated with hallucinations in patients with schizophrenia and patients with Parkinson's disease.

The investigators hypothesize a link between dopaminergic (DA) transmission and reality-monitoring.

Detailed Description

This hypothesis is based on several studies in the literature: 1) DA transmission anomalies are observed in both schizophrenia and Parkinson's disease; 2) DA agonists may induce hallucination; 3) DA antagonists reduce hallucinations and improve reality-monitoring abilities in patients with schizophrenia. In addition, also suggesting a link between mesocorticolimbic connectivity, subcortical DA transmission and reality-monitoring, The investigators have shown that fronto-temporal transcranial Direct Current Stimulation (tDCS) leads:

• on the one hand, to modulate reality-monitoring performance in healthy volunteers and patients;
• on the other hand, to induce subcortical DA release. However, to date, no study has yet explored the direct link between DA transmission and reality-monitoring.

Conditions

Neurosciences

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: SINGLE

Study Groups

Dopamine precursor

In the first condition, volunteers will receive a dopamine (DA) precursor (L-dopa, 100mg). L-dopa will be combined with a dose of an Aromatic amino acid decarboxylase inhibitor (Benserazide) 25mg to multiplicate its bioavailability and with a dose of domperidone 10mg (peripheral antagonist of DA) to minimize the risk of side effects.

Group Type: ACTIVE_COMPARATOR

Précurseur de la dopamine

Intervention Type: OTHER

In the first condition, volunteers will receive a 100mg dose of L-dopa, 25mg dose of Aromatic amino acid decarboxylase inhibitors (Benserazide) and 10mg dose of Domperidone. In the second condition, volunteers will receive Sulpiride 800mg. In the third condition, volunteers will receive placebo Reality-monitoring performances will be evaluated with a standardized task. Working-memory will be evaluated with the n-back task. Self-monitoring performances will be observed during a speech production experiment in which speakers monitor their auditory feedback while speaking.

Speech Bayesian reasoning: This task is a home-made task investigating the influence of prior on speech processing. Subjects will be required to identify speech in ambiguous auditory stimuli. Visual Bayesian reasoning: This task investigates the influence of prior on visual processing. Subjects will be required to recognize morph between faces and house.

D2 antagonist

In the second condition, volunteers will receive a D2 antagonist (Sulpiride, 800mg)

Group Type: ACTIVE_COMPARATOR

antagoniste D2

Intervention Type: OTHER

In the second condition, volunteers will receive Sulpiride 800 mg

PLACEBO

In the third condition, volunteers will receive a placebo (lactose)

Group Type: PLACEBO_COMPARATOR

PLACEBO

Intervention Type: OTHER

In the third condition, volunteers will receive placebo

Interventions

Précurseur de la dopamine

In the first condition, volunteers will receive a 100mg dose of L-dopa, 25mg dose of Aromatic amino acid decarboxylase inhibitors (Benserazide) and 10mg dose of Domperidone. In the second condition, volunteers will receive Sulpiride 800mg. In the third condition, volunteers will receive placebo Reality-monitoring performances will be evaluated with a standardized task. Working-memory will be evaluated with the n-back task. Self-monitoring performances will be observed during a speech production experiment in which speakers monitor their auditory feedback while speaking.

Speech Bayesian reasoning: This task is a home-made task investigating the influence of prior on speech processing. Subjects will be required to identify speech in ambiguous auditory stimuli. Visual Bayesian reasoning: This task investigates the influence of prior on visual processing. Subjects will be required to recognize morph between faces and house.

Intervention Type: OTHER

antagoniste D2

In the second condition, volunteers will receive Sulpiride 800 mg

Intervention Type: OTHER

PLACEBO

In the third condition, volunteers will receive placebo

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Healthy volunteers who have given their written informed consent
• Men and women from 18 to 45 years old
• Normal or corrected vision
• Being fluent in French or French for native language
• Being affiliated with health insurance

Exclusion Criteria

• Healthy volunteers who have given their written informed consent
• Men and women from 18 to 45 years old
• Normal or corrected vision
• Being fluent in French or French for native language
• Being affiliated with health insurance
• Inadmissibility of the subject's consent or refusal
• Working-memory deficit (as controlled with MMSE score< 23)
• Any past or current psychiatric or somatic condition(as controlled with the Mini International Neuropsychiatric Interview, MINI)
• Any past or current neurological condition
• History of cranio-cerebral trauma, arterial hypotension or hypertension, cardiological or serious medical condition
• Abnormal potassium dosage (below 3.1 mmol/L or above 4.9 mmol/L)
• Anormal ECG
• History of schizophrenia or bipolar disorder in first-degree relatives
• Alcohol-drinking and caffeine intake at least during 24 hours before each session
• Drug therapy excepting contraceptives
• Cardiologic or severe medical conditio
• Pregnancy(checked with a pregnancy autotest), lactation, or insufficient contraceptive measure (precautionary measure)
• Consumption of recreational drugs during the last 6 months
• Known sensitivity to any of the study medication and their excipients
• Lactose intolerance
• Porphyria
• Hepatic insufficiency

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Hôpital le Vinatier

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

FILIPE GALVAO

Role: PRINCIPAL_INVESTIGATOR

Centre Hospitalier le Vinatier

Locations

Centre Hospitalier le Vinatier

Bron, , France

Site Status: RECRUITING

Countries

France

Central Contacts

JEROME BRUNELIN

Role: CONTACT

jerome.brunelin@ch-le-vinatier.fr

0033437915565

VERONIQUE VIAL

Role: CONTACT

veronique.vial@ch-le-vinatier.fr

0033437915522

Facility Contacts

Marine Mondino

Role: primary

marine.mondino@ch-le-vinatier.fr

0437915565 ext. +33

Jérôme Brunelin

Role: backup

jerome.brunelin@ch-le-vinatier.fr

0437915297 ext. +33

Other Identifiers

2022-A01345-38

Identifier Type: -

Identifier Source: org_study_id