Higher Order Motion Processing

The role of area V2 in the processing of first- and second-order motion in the human visual cortex has been investigated using fMRI. Retinotopic mapping of visual cortex was first accomplished using contrast-reversing checkerboard hemifields or wedges. Then various first-order and second-order motion and static control stimuli were presented while subjects fixated on the center of the concentric ring stimuli. Regions of interest (ROI) were then applied to the different cortical areas on two-dimensional cortical maps, and the response magnitude for each stimulus condition was determined for each ROI. Areas V1 and V2 responded to all stimuli that contained dynamic flicker and did not prefer stimuli that contained second-order motion signals. This contrasts with the responses in areas V3, VP, V3A, V3B, and MT that demonstrated strong preferences for second-order motion. Thus, the responses in area V2 were governed by local changes in luminance rather than the higher order motion cues.

Understanding And Treating Autism

Understanding And Treating Autism

Whenever a doctor informs the parents that their child is suffering with Autism, the first & foremost question that is thrown over him is - How did it happen? How did my child get this disease? Well, there is no definite answer to what are the exact causes of Autism.

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