Apperceptive agnosia
Each patient that suffers from apperceptive agnosia does not have brain damage in exactly the same area. However, brain damage in proximity to the occipital lobe is largely correlated with the patterns of deficit seen in apperceptive agnosics. For example, patient JB suffered extensive damage to the parietal-occipital areas to the left cerebral hemisphere leading to his deficit in the ability to name distinguish between structurally similar object.
Apperceptive agnosia
Apperceptive visual agnosia results in profound difficulties on a patient's ability to recognize visually presented information. Apperceptive agnosia affects the perceptual processing of individuals. Impairments of elements such as color and motion makes it difficult to interpret shape or the spatial arrangements of objects. Deficits in apperceptive agnosics have not been linked to deficits in acuity. Additionally, patients have an intact ability to attend to cued stimuli. They have the ability to maintain fixation, reach for moving targets, and write as well. Those with apperceptive agnosia, however, have difficultly copying geometric shapes and letters. In some cases individuals are able to trace letters and shapes with their finger but they are unable to use the technique as a strategy to name objects.