Titre
Cue-dependent circuits for illusory contours in humans.
Type
article
Institution
UNIL/CHUV/Unisanté + institutions partenaires
Périodique
Auteur(s)
Anken, J.
Auteure/Auteur
Knebel, J.F.
Auteure/Auteur
Crottaz-Herbette, S.
Auteure/Auteur
Matusz, P.J.
Auteure/Auteur
Lefebvre, J.
Auteure/Auteur
Murray, M.M.
Auteure/Auteur
Liens vers les personnes
Liens vers les unités
ISSN
1095-9572
Statut éditorial
Publié
Date de publication
2016
Volume
129
Première page
335
Dernière page/numéro d’article
344
Peer-reviewed
Oui
Langue
anglais
Résumé
Objects' borders are readily perceived despite absent contrast gradients, e.g. due to poor lighting or occlusion. In humans, a visual evoked potential (VEP) correlate of illusory contour (IC) sensitivity, the "IC effect", has been identified with an onset at ~90ms and generators within bilateral lateral occipital cortices (LOC). The IC effect is observed across a wide range of stimulus parameters, though until now it always involved high-contrast achromatic stimuli. Whether IC perception and its brain mechanisms differ as a function of the type of stimulus cue remains unknown. Resolving such will provide insights on whether there is a unique or multiple solutions to how the brain binds together spatially fractionated information into a cohesive perception. Here, participants discriminated IC from no-contour (NC) control stimuli that were either comprised of low-contrast achromatic stimuli or instead isoluminant chromatic contrast stimuli (presumably biasing processing to the magnocellular and parvocellular pathways, respectively) on separate blocks of trials. Behavioural analyses revealed that ICs were readily perceived independently of the stimulus cue-i.e. when defined by either chromatic or luminance contrast. VEPs were analysed within an electrical neuroimaging framework and revealed a generally similar timing of IC effects across both stimulus contrasts (i.e. at ~90ms). Additionally, an overall phase shift of the VEP on the order of ~30ms was consistently observed in response to chromatic vs. luminance contrast independently of the presence/absence of ICs. Critically, topographic differences in the IC effect were observed over the ~110-160ms period; different configurations of intracranial sources contributed to IC sensitivity as a function of stimulus contrast. Distributed source estimations localized these differences to LOC as well as V1/V2. The present data expand current models by demonstrating the existence of multiple, cue-dependent circuits in the brain for generating perceptions of illusory contours.
PID Serval
serval:BIB_ABE11F3C14D0
PMID
Date de création
2016-02-16T16:35:23.499Z
Date de création dans IRIS
2025-05-21T04:50:09Z
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Nom
26827814_AM.pdf
Version du manuscrit
postprint
Taille
1013.23 KB
Format
Adobe PDF
PID Serval
serval:BIB_ABE11F3C14D0.P001
URN
urn:nbn:ch:serval-BIB_ABE11F3C14D00
Somme de contrôle
(MD5):7c8776d45ed1df2d40a83b8b8ff5994c