HIERARCHY OF VISION

NCT03905616 | Withdrawn

• 2 other identifiers: 69HCL18_09332019-A00465-52
• Study Type: interventional
• Target: N/A
• Locations: 0 countries
• Sites: N/A

Brief Summary

Little is known about the exact role of feedback in cortical processing. Hypotheses on its function range from attentional control to the transmission of Bayesian priors in the interpretation of sensory events, such as in the theory of Predictive Coding. Recent advances in identification of functional signatures of feedback and feedforward signal, as well as additional techniques based on causal relations in signal processing open a unique methodology for probing such processes in awake and behaving organisms and testing these theories and more generally the hierarchical processing between cortical areas. The objective of this project is to study feedback and feedforward relations and localization in the well established pathways between cortical areas V1 and Medial Temporal (MT) that have been implicated in early integration processes in motion perception.

Conditions

Neurologic Signs

Keywords

Vision; perception; BOLD activity

Outcome Measures

Primary Outcomes (1)

• Non-invasive Blood oxygenation level dependent (BOLD) fMRI activity

  Blood oxygenation level dependent (BOLD) imaging is the standard technique used to generate images in fMRI studies, and relies on regional differences in cerebral blood flow to delineate regional activity. This non-invasive technic is not inducing any particular risk. The non invasive BOLD fMRI activity will be recorded in healthy subjects during a task of visual perception.

  At inclusion

Study Arms (1)

healthy subjects

EXPERIMENTAL

25 healthy subjects with a normal/corrected vision fitting to all of the inclusion/exclusion criteria. All the subjects will be tested on the same visual stimuli, leading to intrasubject comparison analyses of functional magnetic resonance imaging (fMRI) activity between conditions.

Device: functional Magnetic Resonance Imaging

Interventions

functional Magnetic Resonance Imaging DEVICE

In a 2-hour session, the subject we be shown different control and experimental conditions (all being visual stimuli) in perceptive tasks.

healthy subjects

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Aged between 18 and 40 years old
• Affiliated to a social security scheme
• Be right-handed
• Have signed the informed consent

You may not qualify if:

• Subjects with a neurological or psychiatric history
• Subjects with visual disturbances not corrected
• Pregnant, lactating or childbearing women without contraception.
• Persons under guardianship, trusteeship or any other administrative or judicial measure of deprivation of rights or liberty, as well as adults protected by law.
• Participants refusing to be informed of the results of the medical examination.
• Participants refusing to be informed of the possible detection of an anomaly.
• Volunteers with contraindications to the MRI examination: people using a pacemaker or an insulin pump, persons wearing a metal prosthesis or an intracerebral clip as well as claustrophobic subjects, neurosensory stimulator or implantable defibrillator, cochlear implants, ferromagnetic foreign body ocular or cerebral close to the nerve structures, agitation of the subject (non-cooperating or agitated subjects), ventriculoperitoneal neurosurgical bypass valves, dental apparatus.

Sponsors & Collaborators

• Hospices Civils de Lyon: lead

MeSH Terms

Conditions

Neurologic Manifestations

Interventions

Magnetic Resonance Imaging

Condition Hierarchy (Ancestors)

Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Tomography; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 4, 2019
• First Posted: April 5, 2019
• Study Start: July 22, 2019
• Primary Completion: February 17, 2021
• Study Completion: February 17, 2021
• Last Updated: February 25, 2021

Record last verified: 2021-02