From phantom limb to phantom body. Varieties of extracorporeal awareness

Abstract

Corporeal awareness refers to the experience of having a body. While this may appear self-evident given our constant daily experience of embodiment, the neuronal processes mediating this experience are nonetheless highly manifold and complex. Corporeal awareness relies on perceptual functions (e.g., tactile, proprioceptive, gravitational, visual) and on motor programs for bodily action. Yet, it also comprises a sense of the self as the object of sensory stimulation and as the agent of motor intentions and executions. Moreover, identifying with a body implies knowledge of its borders. Thus, the study of corporeal awareness includes investigations of the many functionally organized spaces for each distinct sensory and motor representation that surrounds our body. In the past, various terms have been used to capture some of the heterogeneous functions that guarantee a continuous sense of embodiment. Some of the more frequently used terms are body schema, body image, body self, somesthesis, coaenesthesia, and somatognosia. Critchley (1955/1979) complained about the fact that these terms were employed more or less interchangeably despite the fact that they had originally been introduced to designate specific facets of bodily perception and representation. He therefore proposed the deliberately less definitive term corporeal awareness as an all-encompassing descriptor of the experience of having a body.