Types of body representation and the sense of embodiment.

The sense of embodiment is vital for self recognition. An examination of anosognosia for hemiplegia--the inability to recognise that one is paralysed down one side of one's body--suggests the existence of 'online' and 'offline' representations of the body. Online representations of the body are representations of the body as it is currently, are newly constructed moment by moment and are directly "plugged into" current perception of the body. In contrast, offline representations of the body are representations of what the body is usually like, are relatively stable and are constructed from online representations. This distinction is supported by an analysis of phantom limb--the feeling that an amputated limb is still present--phenomena. Initially it seems that the sense of embodiment may arise from either of these types of representation; however, an integrated representation of the body seems to be required. It is suggested information from vision and emotions is involved in generating these representations. A lack of access to online representations of the body does not necessarily lead to a loss in the sense of embodiment. An integrated offline representation of the body could account for the sense of embodiment and perform the functions attributed to this sense.