Abstract
Patients with visual form agnosia are severely impaired at perceptual organization of visual information and consequently, at shape perception and object recognition, despite intact retinal and low level vision. At the same time many of these patients have the intact ability to imagine shapes and objects, implying spared long-term representation of visual information. What remains unclear in these patients is whether they can acquire new long-term visual representations
We studied the ability of a visual form agnosic patient to learn new visual classes, abstracted from simple exemplars (stripes pairs), which were distributed across one dimension (stripe width). Initially, this patient was unable to classify stripes wider than 2 degrees, suggesting a deficit in processing stimuli that require neurons with large receptive fields. However, following long training the patient succeeded to learn the classification pattern, suggesting that he acquired and maintained representations of the new visual classes. The possible loci of plasticity/processing modification will be discussed.