Texture Segregation Processing

fMRI has been used to study the role of area V2 in texture segregation. Topographic mapping of human visual cortex was first performed to distinguish topographically organized visual areas V1, V3A, V4, and TEO. In ventral cortex, areas V2 and VP could not be distinguished from each other in all subjects, and, thus, the relevant data must be attributed to this amalgam. Subjects were presented blank displays or oriented line texture displays that were either homogeneous or contained checkerboard patterns that were defined by oriented line element boundaries. In area V4 of all subjects, the checkerboard pattern evoked a larger fMRI response than did the uniform texture display. Similarly, a statistically greater fMRI response to the checkerboard pattern was observed in area V2-VP of one subject, but this significance was not achieved when all subjects were combined (p<0.08). In area V1, the difference in responses between the homogeneous texture and the checkerboard texture was not significant. A texture segregation index was used to characterize the difference in responses to structured and unstructured textures. The greatest differential response to structured textures occurred in higher cortical areas V4, TEO, and V3A. However, the positive finding in V2-VP for one subject and the near-statistical significance in the pooled data suggest that V2 (VP) may be where the analysis of large-scale texture patterns first begins.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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