MedPath

Study of Visual Mecanisms Involved in Face Recognition

Not Applicable
Not yet recruiting
Conditions
Young Healthy Adults
Healthy
Registration Number
NCT06851923
Lead Sponsor
Université Catholique de Louvain
Brief Summary

Since the 19th century, perception has been regarded as an inferential process in which sensory input is compared with prior knowledge, namely the internalised representation of the visual environment. This notion is central to the understanding of everyday perception and cognition in general, and is attracting much attention in various areas of psychology and cognitive neuroscience. However, it is unclear whether and how the primary visual refinement that is thought to underlie the convergence of bottom-up inputs with top-down prior knowledge applies to the processing of meaningful stimuli in our everyday lives. The investigators have shown that human face processing mechanisms are shaped by prior knowledge that the horizontal range of face information conveys the richest and most reliable cues. Furthermore, investigators' previous data suggest that the primary visual cortex is recruited during the progressive refinement of face representation. Using very high field neuroimaging, the present project proposes to follow the neural mechanisms underlying the cortical refinement of horizontal information in human face processing, and to study their contribution to behaviour.

Detailed Description

Not available

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
100
Inclusion Criteria

Participants will be screened (see annex 2) to ascertain they fit with all these inclusion criteria:

  • Be between 18 and 50 years old,
  • have normal eyesight or eyesight corrected with contact lenses,
  • Have no neurological disorder,
  • Not have had a skull fracture or head surgery,
  • Have no chronic progressive illness or mental deficiency,
  • Have no metal parts in their body (dental braces or pins, metal plates, pacemakers, implanted prostheses, etc.),
  • Have no tattoos containing metallic particles or implanted jewellery (e.g. piercings) that cannot be removed,
  • Not to have worked with metals,
  • Do not take any medicines or substances that may affect brain function (e.g. drugs, energy drinks, alcohol),
  • Not to be pregnant or breastfeeding.
  • Do not be claustrophobic.
Exclusion Criteria

Participants presenting a counter-indication (responding yes to one of the questions of the screening questionnaire, see annex 2) to participate will be excluded from participation.

Participants will be screened to ascertain they do not present any of these counter-indications to the participation to the MRI measurement. We will exclude people with these characteristics:

  • Be younger than 18 or older than 50 years old,
  • have poor eyesight,
  • Have neurological disorder,
  • have had a skull fracture or head surgery,
  • Have a chronic progressive illness or mental deficiency,
  • Have metal parts in their body (dental braces or pins, metal plates, pacemakers, implanted prostheses, etc.),
  • Have tattoos containing metallic particles or implanted jewellery (e.g. piercings) that cannot be removed,
  • have worked with metals,
  • take medicines or substances that may affect brain function (e.g. drugs, energy drinks, alcohol),
  • pregnant or breastfeeding.
  • claustrophobic.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Primary Outcome Measures
NameTimeMethod
Orientation tuning in the visual system2 years

fMRI will be used to analyse brain responses along the ventral visual pathway to the visual presentation of orientation-filtered visual face and scene stimuli

Emergence of orientation tuning over processing course in the visual system2 years

fMRI will be used to analyse brain responses along the ventral visual pathway to the visual presentation of temporally masked orientation-filtered visual stimuli

Receptive field mapping of the visual system2 years

fMRI will be used to measure population receptive fields using stimuli varying in position and size randomly

Behavioral task performance2 years

Participants will identify famous faces presented on-screen and respond via keypress.

Secondary Outcome Measures
NameTimeMethod
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