## Abstract Polymicrogyrias (PMG) are cortical malformations resulting from developmental abnormalities. In animal models PMG has been associated with abnormal anatomy, function, and organization. The purpose of this study was to describe the function and organization of human polymicrogyric cortex
Functional specialization and dynamic resource allocation in visual cortex
β Scribed by Gijs Plomp; Cees van Leeuwen; Andreas A. Ioannides
- Book ID
- 102846140
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 807 KB
- Volume
- 31
- Category
- Article
- ISSN
- 1065-9471
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β¦ Synopsis
Abstract
We studied the spatiotemporal characteristics of cortical activity in early visual areas and the fusiform gyri (FG) by means of magnetoencephalography (MEG). Subjects performed a visual classification task, in which letters and visually similar pseudoletters were presented in different surrounds and under different task demands. The stimuli appeared in a cued half of the visual field (VF). We observed prestimulus effects on amplitudes in V1 and Cuneus relating to VF and task demands, suggesting a combination of active anticipation and specialized routing of activity in visual processing. Amplitudes in the right FG between 150 and 350 ms after stimulus onset reflected task demands, while those in the left FG between 300 and 400 ms showed selectivity for graphemes. The contrasting stimulusβevoked effects in the right and left FG show that the former area is sensitive to task demands irrespective of stimulus content, whereas the left FG is sensitive to stimulus content irrespectively of task demand. Hum Brain Mapp, 2010. Β© 2009 WileyβLiss, Inc.
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