Brain Bases of Natural Scenes's Visual Perception of Natural Scenes

Not Applicable

Completed

• Conditions: Healthy Volunteer
• Interventions: Other: Evaluation of visual function; Other: Magnetic Resonance Imaging

• Registration Number: NCT02840305
• Lead Sponsor: University Hospital, Grenoble

Brief Summary

Using the available data from psychophysics, cellular electrophysiology and functionnal neuroanatomy of visual pathway, current models of visual recognition suppose that the perception of scenes start with a parallel extraction of differents elementary visual characteristics to different spatial frequencies according to a default processing principle named : 'coarse-to-fine'.

According to this principle, the visual scene's analysis would be decomposed in two steps. Fisrt, the fast analysis of the global information borne by low frequency of the scene will provide an overview of the scene's structure and would enable a first perceptive categorisation which would be then refined, approved or denied by the latest analysis of the most local, detailed and precise information, carried by the very high spatial frequency of the scene.

The research carried out since several years is preparing a biologically plausible model and to find brain bases by different imaging techniques among healthy subjects but also patients with a brain lesion and patients with a peripheral lesion.

The main goal of this Magnetic Resonance Imaging study is to find brain bases of natural scenes's visual perception of the natural scenes.

Three studies in Magnetic Resonance Imaging will be conducted, during which subjects will have to categorize pictures of natural scenes filtered in spatial frequencies. The outcome of this study will allow to refine models of visual recognition, most of them based on analysis of spatial frequencies.

Detailed Description

Not available

Study Timeline

• Study Start: 2012-04
• Primary Completion: 2016-03
• Study First Submitted: 2016-07-18
• Study First Submitted QC: 2016-07-18
• Study First Posted: 2016-07-21
• Study Completion: 2016-08
• Status Verified: 2017-01
• Last Update Submitted: 2017-01-17
• Last Update Posted: 2017-01-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 141

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Expérience 1	Magnetic Resonance Imaging	Brain bases of spatial frequencies treatment 30 young adults, 20 old adults 20 children between 4 and 6 years, 20 children between 6 and 12 years and 20 young adults
Expérience 1	Evaluation of visual function	Brain bases of spatial frequencies treatment 30 young adults, 20 old adults 20 children between 4 and 6 years, 20 children between 6 and 12 years and 20 young adults
Expérience 3	Evaluation of visual function	Part of parahippocampal gyrus in Computer to Film (CtF) analysis 30 young adults, 20 old adults.
Expérience 3	Magnetic Resonance Imaging	Part of parahippocampal gyrus in Computer to Film (CtF) analysis 30 young adults, 20 old adults.
Expérience 2	Evaluation of visual function	Brain bases of Computer to Film (CtF) analysis 30 young adults, 20 old adults
Expérience 2	Magnetic Resonance Imaging	Brain bases of Computer to Film (CtF) analysis 30 young adults, 20 old adults

Primary Outcome Measures

Name	Time	Method
Identify brain bases of natural scenes's visual perception of the natural scenes	About 80 minutes	Evaluation 1 = Visual tasks Experience 1 : Brain bases of spatial frequencies treatment Experience 2 : Brain bases of Computer to Film (CtF) natural scenes analysis MRI exam Experience 3 : Part of parahippocampal gyrus in Computer to Film (CtF) natural scenes analysis MRI exam About 30 minutes; Evaluation 2 = Retinotopy : only adults that have shown activations inside occipital cortex during evaluation 1 MRI exam about 50 minutes

Trial Locations

Locations (1)

UniversityHospitalGrenoble; 🇫🇷 La Tronche, France