The Consciousness Delusion

"You don't have a soul. You are a soul. You have a body."   C.S. Lewis

Wherever you are reading this, take a moment now and notice your body: Are your legs crossed? Is your posture straight or are you slouching? Are you slightly warm or cold? Now notice your surroundings: Is your body in a serene or noxious environment?  Is it being transported in a moving vehicle, rocking slightly from side to side? If you could precisely answer any of those questions, congratulations! You are conscious. How consciousness arises from, as the great neuroscientist V.S. Ramachandran mused, "a three-pound mass of jelly that you can hold in your palm" is one of science's deepest enigmas.  At the present moment, two of its components - body ownership and self-location - are studied in the brain using multi sensory bodily illusions and MRI.

 Body ownership.

You own a body. Your body.  Although similar to other bodies ambulating Earth, your body is unique in appearance and movement. How do you know your body is yours?

In a 2011 study, Petkova et al had participants feel touch on their chest in the MRI while viewing a mannequin also being touched on its chest (See below). 

This is known as the "body swap illusion."  The most important thing to gather from this study is that the virtual body was viewed from a first-person perspective, the same view one would see if touching their own body.  Activity in the vPMc (ventral premotor cortex) correlated with the strength of the virtual body illusion.  In other words, the participant felt the ownership of a body that was not their own. Among many fascinating stories, Sam Kean describes in his book, The Tale of the Dueling Neurosurgeons, the way V.S. Ramachandran tricked the brains of WWI amputees to "see" their phantom limb: by simply placing a mirror alongside their existing limb.   This allowed the patient's brain to virtually "own" an absent part of their body. 

Self Location.

Ionta et al, by contrast had participants feel touch on their back while videos of a human body were being touched on its back (See above).

The main difference is that the virtual body was viewed from a third-person perspective, a location other than that occupied by their own body.  The right and left (TPJ) temporo-parietal-junction were activated in these subjects, areas important for the integration of inputs from "tactile, proprioceptive and visual systems, and critically, from the vestibular system."  In other words, the participants felt a kinship with the virtual body, but not in the same location/space.  Lesions in this area result in "out of body experiences." 

 Out of body experiences refer to the sensations of being located outside the physical body and of seeing and perceiving the world and sometimes oneself from a location outside own physical body, as if taking a third-person perspective of one's body.

Alien Abduction.

Can you own a body without changing its location? Yes.  Can you then change its location and still keep your body? No. Clinical evidence supports this claim.  During out-of-body experiences, patients report "a loss of connection between the self and the physical body" and "a strong affinity with the seen body while their sense of location is strongly disturbed."  Dissociating body ownership and self-location implies the two rely on distinctly different neural networks.

Certitude about Consciousness.

Another key area for sensory self-monitoring is the insular cortex.  The enfacement illusion, in which stimulation between one's own and another person's face is used to evoke changes in self-identification, shows activity in this area.  Interestingly, participants with “high interoceptive awareness are less ready to experience ownership, probably because they have a stronger sense of ownership for their own body.”  Namely, if you have strong sense of what your body feels like – you won’t be easily fooled.  The authors also shared this illusion correlated positively with emphatic traits.   A large body of evidence suggests that the TPJ is involved in mind-reading, theory of mind, and empathy.  In other words, a shift in perspective. Besides illuminating the dark corridors of consciousness, the implications of understanding empathy on such a grand scale are incredibly encouraging. 

If your emotional abilities aren't in hand, if you don't have self-awareness, if you are not able to manage your distressing emotions, if you can't have empathy and have effective relationships.  Daniel Goleman
ResearchBlogging.org Serino, A., Alsmith, A., Costantini, M., Mandrigin, A., Tajadura-Jimenez, A., & Lopez, C. (2013). Bodily ownership and self-location: Components of bodily self-consciousness Consciousness and Cognition, 22 (4), 1239-1252 DOI: 10.1016/j.concog.2013.08.013