Certain specific disabilities following lesions of the dominant hemisphere particularly those involving the parietal region, have been recognized for many years. The syndrome of dyscalculia, dysgraphia, right-left disorientation and finger agnosia is usually known as Gerstmann's syndrome, following that author's descriptions in 1924 and 1940. It has been suggested that of these four main components of the syndrome, finger agnosia might be the fundamental disturbance, bringing the others in its train. Thus, as a result of the postulated importance of the digits for numeration, acalculia would naturally follow. Dysgraphia would result from the loss of the “schema” for the fingers—a part of the body-image—and right-left disorientation might be a consequence of the same body-image disturbance—a “hand” agnosia.