An out-of-body experience (OBE) involves viewing one's body and surroundings from outside the physical self. While prior research linked OBEs to the temporoparietal junction, this case report describes a 46-year-old woman who experienced monthly OBEs before surgery for a brain tumor in the posterior cingulate cortex (PCC) and none afterward. Her OBEs involved a clear separation of the subjective and objective bodies. The case suggests the PCC may play a role in creating spatial unity between self and body, with its removal eliminating the experiences.
The subjective feeling that consciousness is singular—that there is only one 'me'—may be an illusion created by the need to respond coherently to the environment. A review of neuropsychological conditions such as anosognosia, neglect, and split-brain, alongside psychiatric disorders and psychoactive drugs, suggests that perceptual, language, memory, attentional, and motor processes can operate largely in parallel without integration. The sense of unity, or 'Me-ness', arises only when an organism must produce a coherent response constrained by environmental affordances.