Neuropsychological considerations of drawing and seeing pictures
Introduction Pictures are commonly used as stimuli in neuropsychological tests. Since left hemisphere damage often leads to language impairment, pictures are used to assess the extent of impairment through such non-verbal means. Similarly, damage in the right hemisphere can result in loss of previous knowledge, of familiar faces, objects, maps, and spatial layouts, so pictures are used to determine what knowledge is preserved. In a wide range of neurological brain disorders there is no apictoria (a selective loss of the ability to understand any pictorial representation). With visual object agnosia there may be an impairment in deriving the meaning of pictured objects but the same patient may not have problems with recognizing pictured faces, pictures of scenes, of geometrical shapes, or of nonsense shapes. Primates, birds, and rats can be trained to respond to pictures. But, unlike humans, they cannot produce them. The production may be unique but the communicative value of pictures, on a certain level, is not unique to humans.