Sunday, May 29, 2011

two brains - two minds

Video - Dr. Strangelove survival plan and split-brained body misbehavior.

Journal of Cosmology | It is commonly supposed that consciousness has mental unity which is supported by the brain. However, it has been demonstrated that consciousness is actually a multiplicity which includes a duality maintained by the right and left half of the brain. In the normal brain it has sometimes been supposed that mental unity is supported and maintained via the extensive bridge of nerve fibers which interconnect the right and left cerebral hemispheres; i.e. the corpus callosum, and that only in conditions such as following callosotomy, does something akin to a splitting of the mind occur. Split-brain functioning following sectioning of the corpus callosum is discussed and a case study is presented. However, surgery provides only the most dramatic examples of this duality. Split-brain functioning is also characteristic during early childhood, and the results from experiments demonstrating this duality are presented. Further, partial splitting of the mind is evident even in the normal brain. It often occurs that people will express certain behaviors, act on various impulses, make "thoughtless", embarrassing statements or a "slip of the tongue" and "have no idea" as to "what came over" them. In some instances they may even fail to become aware that anything unusual or objectionable has resulted, or conversely, conjure up explanations for their actions. Similar anomolies confront us in regard to certain emotions, desires, impulses, and conflicts --the origins and source of which are seemingly submerged and hidden; at least from the language dominant hemisphere which maintains the language-dependent aspects of consciousness (i.e. in most instances the left). Because each half of the brain subserves unique (albeit overlapping) functions, such that functional lateralization is characteristic, in some situations one brain half may have little or no knowledge as to what is occurring in the other. Some forms of information cannot be transferred or even recognized by the opposite hemisphere. Functional lateralization also leads to the experience of forgotten dreams; and this is because it is the right hemisphere which produces much of the imagery experienced during the dream, whereas it is the left hemisphere which forgets the dream upon wakening. When the left hemisphere is denied access to information retained or processed by the right, and/or is unable to learn why a certain behavior or action was initiated, it typically makes up explanations (which it believes) or engages in active denial. These dualities are most evident following split-brain surgery, but can also explain some of the unique mental characteristics of childhood and the emotional difficulties experienced by the normal brain and the conscious mind.