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Neuroelectromagnetic correlates of perceptual closure processes.
- Source :
-
The Journal of neuroscience : the official journal of the Society for Neuroscience [J Neurosci] 2010 Jun 16; Vol. 30 (24), pp. 8342-52. - Publication Year :
- 2010
-
Abstract
- Perceptual closure refers to the coherent perception of an object under circumstances when the visual information is incomplete. Although the perceptual closure index observed in electroencephalography reflects that an object has been recognized, the full spatiotemporal dynamics of cortical source activity underlying perceptual closure processing remain unknown so far. To address this question, we recorded magnetoencephalographic activity in 15 subjects (11 females) during a visual closure task and performed beamforming over a sequence of successive short time windows to localize high-frequency gamma-band activity (60-100 Hz). Two-tone images of human faces (Mooney faces) were used to examine perceptual closure. Event-related fields exhibited a magnetic closure index between 250 and 325 ms. Time-frequency analyses revealed sustained high-frequency gamma-band activity associated with the processing of Mooney stimuli; closure-related gamma-band activity was observed between 200 and 300 ms over occipitotemporal channels. Time-resolved source reconstruction revealed an early (0-200 ms) coactivation of caudal inferior temporal gyrus (cITG) and regions in posterior parietal cortex (PPC). At the time of perceptual closure (200-400 ms), the activation in cITG extended to the fusiform gyrus, if a face was perceived. Our data provide the first electrophysiological evidence that perceptual closure for Mooney faces starts with an interaction between areas related to processing of three-dimensional structure from shading cues (cITG) and areas associated with the activation of long-term memory templates (PPC). Later, at the moment of perceptual closure, inferior temporal cortex areas specialized for the perceived object are activated, i.e., the fusiform gyrus related to face processing for Mooney stimuli.
- Subjects :
- Adult
Cerebral Cortex anatomy & histology
Cerebral Cortex blood supply
Electroencephalography methods
Female
Functional Laterality physiology
Humans
Image Processing, Computer-Assisted methods
Magnetic Resonance Imaging methods
Male
Oxygen blood
Pattern Recognition, Visual physiology
Photic Stimulation methods
Reaction Time physiology
Spectrum Analysis methods
Time Factors
Visual Pathways blood supply
Visual Pathways physiology
Young Adult
Brain Mapping
Cerebral Cortex physiology
Magnetoencephalography methods
Perceptual Closure physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1529-2401
- Volume :
- 30
- Issue :
- 24
- Database :
- MEDLINE
- Journal :
- The Journal of neuroscience : the official journal of the Society for Neuroscience
- Publication Type :
- Academic Journal
- Accession number :
- 20554885
- Full Text :
- https://doi.org/10.1523/JNEUROSCI.5434-09.2010