Chromatic and Motion Processing

Early positron emitted tomographic (PET) studies of the functional organization of visual cortex in humans have concentrated on determining the location and specialization of the human homologs of macaque monkey areas V4 and MT. In a color-processing study aimed at identifying human homologs, regional cerebral blood flow (rCBF) measures were made while subjects viewed either chromatic or gray Mondrian patterns. Two statistically significant foci of activation were observed in the visual cortex: one in the occipital pole corresponding to V1-V2 and a second area in the lingual and fusiform gyrus corresponding to V4. In a motion-processing study aimed at identifying human MT, rCBF measures were made while subjects viewed either stationary or moving small black squares. Again two statistically significant foci were observed: one corresponding to V1-V2 and the second at the junction of the parietal and occipital cortices corresponding to area MT. Given the spatial resolution of the PET technique and the similarity of response properties in V1 and V2, these authors were unable to distinguish activation in V2 from that in V1. Nevertheless, this focus was active in each of the four stimulus conditions tested. Thus, V1-V2 were found to participate in both chromatic and gray scale analyses as well as in stationary and moving square analyses.

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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