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Brain mechanisms for perceiving illusory lines in humans.

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Název: Brain mechanisms for perceiving illusory lines in humans.
Autoři: Anken, J., Tivadar, R.I., Knebel, J.F., Murray, M.M.
Rok vydání: 2025
Sbírka: Université de Lausanne (UNIL): Serval - Serveur académique lausannois
Témata: Adult, Contrast Sensitivity/physiology, Electroencephalography/methods, Evoked Potentials, Visual/physiology, Female, Functional Neuroimaging/methods, Humans, Illusions/physiology, Male, Occipital Lobe/diagnostic imaging, Occipital Lobe/physiology, Pattern Recognition, Visual Cortex/diagnostic imaging, Visual Cortex/physiology, Young Adult, Event-related potential (ERP), Illusory contour, Kanizsa, Visual evoked potential (VEP)
Popis: Illusory contours (ICs) are perceptions of visual borders despite absent contrast gradients. The psychophysical and neurobiological mechanisms of IC processes have been studied across species and diverse brain imaging/mapping techniques. Nonetheless, debate continues regarding whether IC sensitivity results from a (presumably) feedforward process within low-level visual cortices (V1/V2) or instead are processed first within higher-order brain regions, such as lateral occipital cortices (LOC). Studies in animal models, which generally favour a feedforward mechanism within V1/V2, have typically involved stimuli inducing IC lines. By contrast, studies in humans generally favour a mechanism where IC sensitivity is mediated by LOC and have typically involved stimuli inducing IC forms or shapes. Thus, the particular stimulus features used may strongly contribute to the model of IC sensitivity supported. To address this, we recorded visual evoked potentials (VEPs) while presenting human observers with an array of 10 inducers within the central 5°, two of which could be oriented to induce an IC line on a given trial. VEPs were analysed using an electrical neuroimaging framework. Sensitivity to the presence vs. absence of centrally-presented IC lines was first apparent at ∼200 ms post-stimulus onset and was evident as topographic differences across conditions. We also localized these differences to the LOC. The timing and localization of these effects are consistent with a model of IC sensitivity commencing within higher-level visual cortices. We propose that prior observations of effects within lower-tier cortices (V1/V2) are the result of feedback from IC sensitivity that originates instead within higher-tier cortices (LOC).
Druh dokumentu: article in journal/newspaper
Popis souboru: application/pdf
Jazyk: English
ISSN: 1095-9572
Relation: NeuroImage; https://iris.unil.ch/handle/iris/104789; serval:BIB_3507DEC71B52; 000445165600016
DOI: 10.1016/j.neuroimage.2018.07.017
Dostupnost: https://iris.unil.ch/handle/iris/104789
https://doi.org/10.1016/j.neuroimage.2018.07.017
Přístupové číslo: edsbas.380E552E
Databáze: BASE
Popis
Abstrakt:Illusory contours (ICs) are perceptions of visual borders despite absent contrast gradients. The psychophysical and neurobiological mechanisms of IC processes have been studied across species and diverse brain imaging/mapping techniques. Nonetheless, debate continues regarding whether IC sensitivity results from a (presumably) feedforward process within low-level visual cortices (V1/V2) or instead are processed first within higher-order brain regions, such as lateral occipital cortices (LOC). Studies in animal models, which generally favour a feedforward mechanism within V1/V2, have typically involved stimuli inducing IC lines. By contrast, studies in humans generally favour a mechanism where IC sensitivity is mediated by LOC and have typically involved stimuli inducing IC forms or shapes. Thus, the particular stimulus features used may strongly contribute to the model of IC sensitivity supported. To address this, we recorded visual evoked potentials (VEPs) while presenting human observers with an array of 10 inducers within the central 5°, two of which could be oriented to induce an IC line on a given trial. VEPs were analysed using an electrical neuroimaging framework. Sensitivity to the presence vs. absence of centrally-presented IC lines was first apparent at ∼200 ms post-stimulus onset and was evident as topographic differences across conditions. We also localized these differences to the LOC. The timing and localization of these effects are consistent with a model of IC sensitivity commencing within higher-level visual cortices. We propose that prior observations of effects within lower-tier cortices (V1/V2) are the result of feedback from IC sensitivity that originates instead within higher-tier cortices (LOC).
ISSN:10959572
DOI:10.1016/j.neuroimage.2018.07.017