Sequential computed tomography scans in acute cerebral infarct.

We reported double-dissociation between the visual processing of the edges and the surfaces of objects. Patients with lateral occipital damage showed selective impairment in the perception of edges whereas those with medial ventral occipital damage showed selective impairment in the perception of the 3D structure of the surface. Patients with medial ventral occipital damage also exhibited impaired perception of color, which is also a surface property. Those results were consistent with those from neuroimaging studies. Taken together, those studies suggest that objects may be processed in two separate pathways in the ventral occipital cortex: the edges of objects are processed in the lateral pathway and the surface of objects are processed in the medial pathway. Both edges and surfaces play important roles in object recognition, and both types of perception should be evaluated in patients with visual agnosia.

Cerebral Infarction↗