The ancient question of what it means to be conscious is generally associated with animals possessing relatively more complex brains and cognitive abilities. Closely tied to consciousness is the idea of self awareness, thought to be even more evolutionarily advanced than consciousness. Most scientist agree that consciousness is defined as " the ability to think" while self awareness is defined as " being able to realize that one is a thinking being and having the ability to think about one's thoughts". However research has been done in recent years that challenges this assumption. A review published in 1999 compiled case studies of children with hydranencephaly, the most severe form of bilateral cerebral cortical destruction which results in the complete absence of the cerebral hemispheres. In some of these cases, the children were able to respond to and recognize others, interact with their environment, show emotion (ie. laugh, smile, and cry), and process sounds, even showing preference for certain types of music. Clearly these children are what we would deem "conscious". A study by Philippi and Rudrauf published earlier this year, focuses on a patient named Roger who suffered from herpes simplex encephalitis. Most of his insular cortex, anterior cingulate cortex and medial prefrontal cortex were destroyed by his illness. These are the very regions that current science tells us are responsible for self awareness, a trait thought to be even more complex in origin, a progression of consciousness. However, after a battery of rigorous testing, Phillipi and Rudrauf found that Roger, despite many cognitive deficits, maintains his self-awareness. The two researchers use their own work with Roger as well as the 1999 study as evidence that consciousness and self awareness are arguably more rudimentary and less dependent on the cerebral cortex than previously thought. If it is possible to be conscious (and maybe even self-aware) without a brain, what other animals or non-animals are out there thinking, or thinking about their thoughts?
Jabr, Ferris. Nov/Dec. 2012. Self Awareness with a Simple Brain. Scientific American Mind, 28-29.
This is fascinating. I have just read an article about the study done in the University of Iowa challenging the idea that there are only three brain regions important for self awareness : the insular cortex, the anterior cingulate cortex, and the medial prefrontal cortex. Recently, it is suggested that there are more areas associated with self awareness that create a complex, diffuse patchwork of pathways. Perhaps, this finding can help explaining why patients, like Roger display self awareness while missing all the areas that are typically thought to be needed for self awareness.
ReplyDelete