Completed

NCT Number: NCT02840305

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

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.

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Key information

Conditions

Healthy Volunteer

Age range

4 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

UniversityHospitalGrenoble

La Tronche, 38700, France

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

for young adults :

Subjet over 18 years and less than 30 years
Affiliation to a social security
Free signed consent
Medical exam done before participation to the study
Normal or corrected visual acuity

Exclusion criteria

four young adults :

Counter-argument to MRI
Pregnant, breast-feeding or parturient women
Adults non protected or unable to express their consent
Adults protected
Important earing or visual disorder
Neuropsychiatric disorder current or past passée ou présente (exept benign epilepsy)
Severe affection on a general level (cardiac, respiratory, hematologic, renal, hépatic, cancerous)
Drug treatment in progress (exept anti-epileptic drug) likely to de modulate brain activity

Inclusion criteria

for old adults :

Subjet over 50 years
Affiliation to a social security
Free signed consent
Medical exam done before participation to the study
Normal or corrected visual acuity

Exclusion criteria

four old adults :

Counter-argument to MRI
Pregnant, breast-feeding or parturient women
Adults non protected or unable to express their consent
Adults protected
Important earing or visual disorder
Neuropsychiatric disorder current or past passée ou présente (exept benign epilepsy)
Severe affection on a general level (cardiac, respiratory, hematologic, renal, hépatic, cancerous)
Drug treatment in progress (exept anti-epileptic drug) likely to de modulate brain activity

Inclusion criteria

for children :

Children between 4 and 12 years
Affiliation to a social security
Free signed consent
Medical exam done before participation to the study
Normal or corrected visual acuity

Exclusion criteria

four children :

Counter-argument to MRI
Important earing or visual disorder
Important development disorder and/or acquisitions identified by parents and/or school teachers
Neuropsychiatric disorder current or past passée ou présente (exept benign epilepsy)
Severe affection on a general level (cardiac, respiratory, hematologic, renal, hépatic, cancerous)
Drug treatment in progress (exept anti-epileptic drug) likely to de modulate brain activity

Treatment and study plan

Evaluation of visual function

Other

Magnetic Resonance Imaging

Other

Other names: MRI

Primary outcomes

Identify brain bases of natural scenes's visual perception of the natural scenes

Time frame: 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

Sponsors and collaborators

Lead sponsor

University Hospital, Grenoble

Other

Registry information

Official study title

Brain Bases of Visual Perceptionnatural Scenes of Natural Scenes.

Acronym: SCENES

Important dates

Study start: 2012
Primary completion: 2016
Study completion: 2016
First posted: Jul 21, 2016
Registry last updated: Jan 18, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

Completed