Anomia in cerebral diseases.

Naming performance was studied in demented patients, age-matched controls, left-hemisphere stroke patients with aphasia and right-hemisphere stroke patients. The experimental naming test compared four levels of perceptual difficulty and two language variables: word frequency and word length. Naming accuracy and error types were compared among subject groups. Perceptual difficulty influenced naming in the demented and right-hemisphere stroke patients, but not in aphasics and controls. Visual errors, likewise, characterized the former two groups. Semantically-related errors and circumlocutions characterized the naming of aphasic and demented patients, while phonemic errors were common only in aphasics. The results suggested differing patterns of anomia in different patient groups.