NCT05711082

REALITY MONITORING

MONITORING OF REALITY AND DOPAMINE: A PHARMACOLOGICAL RESEARCH

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 39 (estimated)
• Sponsor: Hôpital le Vinatier · Academic / Other
• Sex: All
• Age: 18 Years – 45 Years
• Healthy volunteers: Accepted

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

Interventions

Type	Name	Description
OTHER	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.
OTHER	antagoniste D2	In the second condition, volunteers will receive Sulpiride 800 mg
OTHER	PLACEBO	In the third condition, volunteers will receive placebo

Timeline

• Start date: 2024-01-15
• Primary completion: 2026-06-30
• Completion: 2026-12-31
• First posted: 2023-02-02
• Last updated: 2025-03-06

Locations

1 site across 1 country: France