Dynamics of perceptual decisions about symmetry in visual cortex.
Neuroimage
; 167: 316-330, 2018 02 15.
Article
em En
| MEDLINE
| ID: mdl-29175495
ABSTRACT
Neuroimaging studies have identified multiple extra-striate visual areas that are sensitive to symmetry in planar images (Kohler et al., 2016; Sasaki et al., 2005). Here, we investigated which of these areas are directly involved in perceptual decisions about symmetry, by recording high-density EEG in participants (n = 25) who made rapid judgments about whether an exemplar image contained rotation symmetry or not. Stimulus-locked sensor-level analysis revealed symmetry-specific activity that increased with increasing order of rotation symmetry. Response-locked analysis identified activity occurring between 600 and 200 ms before the button-press, that was directly related to perceptual decision making. We then used fMRI-informed EEG source imaging to characterize the dynamics of symmetry-specific activity within an extended network of areas in visual cortex. The most consistent cortical source of the stimulus-locked activity was VO1, a topographically organized area in ventral visual cortex, that was highly sensitive to symmetry in a previous study (Kohler et al., 2016). Importantly, VO1 activity also contained a strong decision-related component, suggesting that this area plays a crucial role in perceptual decisions about symmetry. Other candidate areas, such as lateral occipital cortex, had weak stimulus-locked symmetry responses and no evidence of correlation with response timing.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Reconhecimento Visual de Modelos
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Desempenho Psicomotor
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Percepção Espacial
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Córtex Visual
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Imageamento por Ressonância Magnética
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Eletroencefalografia
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Neuroimagem Funcional
Tipo de estudo:
Prognostic_studies
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article