Sensory and Cognitive Predictions, and Their Disruptions in Schizophrenia (SensoSchiz)

Disturbances in the sense of self and time could play an important role in the development of psychotic symptoms. Previous work has shown that patients have difficulty preparing to process information on the scale of a second, but are abnormally disturbed by slightly asynchronous information on the millisecond scale. In both cases, the anomalies could explain the patients' unusual experience of time. The hypothesis in neurotypical patients is that small delays or asynchronies asynchronies are treated as irrelevant information and ignored and ignored, whereas in patients suffering from schizophrenia they would disrupt the flow of time. This hypothesis is tested with a new visual illusion.

Study Overview

• Status: Not yet recruiting
• Conditions: Schizophrenia; Sensory Processing Disorder
• Intervention / Treatment: Behavioral: Illusion task

Detailed Description

In the task, two squares move at constant speed in a straight line towards each other. When they collide and disappear neurotypical individuals perceive a gap between the two squares rather than contact. This unexpected effect cannot be explained by a 'cognitive' expectation, since what is consciously expected is collision and contact. It has been shown that it is sensory predictions which explain the illusion of space at the moment of contact. Indeed, a movement trajectory is accompanied by sensory predictions, which help to anticipate the position of the moving object, and of the contrast between the edges of the squares and the background. At the moment of collision, the contrast disappears and is processed as a prediction error. If subjects do not have time to correct the error, they see a gap, as if the figure-ground contrast was still there. Conversely, when a rebound effect is introduced into the task (the squares are moved in the opposite direction after the collision), the illusion diminishes, as if the rebound reinforces the (top-down) expectation of a collision.

Perturbations will be introduced during the trajectory in the illusion task with and without rebound to test this hypothesis (acceleration on a millisecond scale vs. uniform speed). Patients suffering from schizophrenia, whose prediction mechanisms are fragile, are expected to be abnormally sensitive to trajectory changes. The experimental manipulations will help to compare sensory prediction (illusion without rebound) and top-down (conscious) prediction (illusion with rebound).

The protocol will also help to specify which types of prediction (sensory or cognitive) underlie patients' sense patients' sense of self. In short, the protocol is designed to improve the pathophysiological understanding of sense-of-self disorders in schizophrenia

• Study Type: Interventional
• Enrollment (Estimated): 68
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Anne Giersch, MD PhD; Phone Number: 0033 3 88 116471; Email: giersch@unistra.fr
• Study Contact Backup: Name: Naoual MELLOUKI BENDIMRED, PhD; Phone Number: 0383925267; Email: unic@cpn-laxou.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Male or female;
• Age between 18 and 60 inclusive;
• Subject having dated and signed the consent form prior to the start of any trial-related procedure (guardian or curator where applicable);
• Member of a social security scheme or beneficiary of such a scheme.

Exclusion Criteria:

• Psychoactive substance use disorders (as defined by the DSM-V) (Diagnostic and Statistical Manual-V);
• Use of benzodiazepines, hallucinogens (in the period preceding before inclusion, for a duration equivalent to 5 half-lives of the product) or cannabis (in the 2 months preceding inclusion);
• Neurological pathology or sequelae;
• Attention deficit hyperactivity disorder (ADHD);
• Borderline personality disorder;
• Disabling sensory disorders (visual acuity <0.8);
• Person deprived of liberty or under court protection;
• Pregnant, parturient or breast-feeding women;
• Subjects in a period of exclusion defined by another clinical study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: effect of trajectory perturbation; All participants will run the task consisting in 2 squares moving towards each other. On each trial they will answer whether the squares touch or do not touch. All participants are tested with all experimental conditions. The rate of 'touch' responses will be compared when there is a trajectory perturbation without rebound vs. a trajectory with perturbation with rebound vs. a trajectory without perturbation and without rebound vs. a trajectory without perturbation and with rebound.

Behavioral: Illusion task; The task is the illusion already described in the arm description. All participants will additionally benefit from a short neuropsychological evaluation exploring attention (CPT-AX) and semantic knowledge (fNART) and a clinical evaluation exploring the sense of self (EASE).; Other Names: EASE evaluation; fNART; CPT-AX

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effect of a millisecond-level trajectory perturbation	Change in the rate of illusion in case of a trajectory perturbation (compared to the rate of illusion in the absence of perturbation)	Month 4

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Baseline rate of illusion	Frequency of the illusion perception when there is no trajectory perturbation and no rebound after the collision	month 4
Effect of a rebound (top-down, conscious influence)	Change in the rate of illusion in case of a rebound (compared to the rate of illusion in the absence of rebound)	month 4

Collaborators and Investigators

• Sponsor: Centre Psychothérapique de Nancy
• Collaborators: Institut National de la Santé Et de la Recherche Médicale, France
• Investigators: Principal Investigator: Anne Giersch, MD PhD, Institut National de la Santé Et de la Recherche Médicale, France

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2024
• Primary Completion (Estimated): April 30, 2027
• Study Completion (Estimated): February 28, 2028

Study Registration Dates

• First Submitted: April 3, 2024
• First Submitted That Met QC Criteria: April 9, 2024
• First Posted (Actual): April 11, 2024

Study Record Updates

• Last Update Posted (Actual): April 11, 2024
• Last Update Submitted That Met QC Criteria: April 9, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Keywords: sensory prediction; motion perception; prediction error
• Additional Relevant MeSH Terms: Mental Disorders; Schizophrenia Spectrum and Other Psychotic Disorders; Schizophrenia
• Other Study ID Numbers: 2023-A02464-41

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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