DEVELOPMENTAL ASPECTS OF THE BODY SCHEME

Abstract

The studies reported pertain to the basic body scheme in Henry Head's sense, that is, a stable cognitive structure built up from past sensory experience. The postamputation phantom is viewed as a symptom of the persisting schema. Investigations of individuals with congenitally missing limbs, of childhood amputees, of mentally defective amputees, and of patients with leprosy having lost body parts surgically or through absorption show that past sensory experience is a crucial determinant of the emergence of the phantom and, therefore, of the persistent body scheme. Such sensory experience depends both on sensory input and some minimal stability of cognitive organization. In current discussions it often appears as if Head's (Head & Holmes, 1911-12; 1912) notion of the postural-tactile model of the body were merely of historical interest. Evidently his scheme of the body served as a point of departure for Schilder (1935), who promptly elaborated it into a much more complex body image, a concept that has caught the sometimes rather fanciful imagination of many writers since. This, it seems to me, is a very onesided reading of history. Head's notion was a systematic concept, filling a systematic need. It arose from observation of patients with disturbances, due to cerebral lesions, in the recognition of body posture and passive motion. These observations of instances in which the simple peripheral correlates of perception had been impaired forced him to consider the organization of past experience. In brief, Head argued that perception of the position of the body, and of changes in position, whether actively or passively produced, does not depend solely on the specific input from proprioceptive receptor