Higher cortical visual function.

Abstract

Higher cortical visual function continues to be explored with both lesion and functional imaging studies. Studies with functional MRI confirm that the fusiform gyri are involved in color and face perception, and show multiple regions participating in motion perception, including V5, V3A, and a new area, the kinetic occipital region. There were numerous blindsight reports, including studies of spatial summation and "inhibition of return," and a refutation of the argument that blindsight is merely a "criterion shift." However, other studies failed to find blindsight-like ocular motor responses to moving stimuli. Occipitotemporal lesions were found to cause defects in perception of both first- and second-order motion. The psychophysical impairments of the motion-blind patient LM were shown to be similar to those of monkeys with V5 ablations, suggesting a close homology between this monkey visual area and the human motion area in the lateral occipitotemporal cortex.