A neuropsychological disorder in which a person is unable to recognize objects by touch, despite retained tactile sensitivity, strength, and coordination. That is, with the eyes closed or without visual control, the patient cannot identify familiar objects (for example, keys or coins), even if he feels their shape and texture.The condition usually occurs when the parietal lobe of the brain, especially the opposite somatosensory cortex, which processes bodily sensations, is affected.