Human Responses to the Human Split Brain :: Biology Essays Research Papers

When neuroscientists first made rate contact with the right cerebral cerebral hemisphere of the brain, during neurological tests of split brain gay subjects, it was as if they had found intelligent, albeit speechless, life on Mars. At a era when brain imaging techniques were crude or nonexistent, the only way to keep on and communicate with the brains right hemisphere unimpeded by the left hemisphere was by testing split brain subjects (1). The right hemisphere, previously suppositional mute, illiterate, mentally retarded, and completely subordinate to the left hemisphere, had a mind of its birth (1). While it could not speak, it could respond to commands and questions via its contralateral control of the left hand. It had dissimilar abilities and even opinions and emotional states than the neighboring left hemisphere (2). These discoveries led to a model of hemispheric specialization of normal tender-hearted brain function, with an analytic, verbal, conundrum solving left h emisphere and a visuospatial, synthetic, creative right hemisphere (1, 2). The formation of this model in turn offers insight into the brains of the observers as easily as the observed. The observers behavior supported some of their own hypotheses about the human brain, split or unsplit.The term split-brain is commonly used to describe a person whose corpus callosum has been surgically severed (3). The corpus callosum, comprised of approximately cc million neuronal fibers connecting the left and right hemispheres of brain, exists only in mammals brains, and is largest in human brains (1, 3). Until the 1960s neuroscientists were unsure what purpose the corpus callosum served (3). By observing deficits in split brains functions, scientists could better assess the corpus callosums function (1). Roger Sperry and his colleagues pioneered the operation rift the corpus callosum, known as callosal commisurectomy, in the 1960s, as a hold out ditch effort to control the seizures of life th reateningly severe epilepsy by creating a fire wall to prevent electrical impulses from traveling betwixt hemispheres (1). This treatment was successful, and after recovering from the surgery, the split-brain patients appeared normal in every twenty-four hour period interactions and even during a routine physical exam (1). However, Sperry and his colleagues, after abundant and specific neurological tests of split brain patients, posited that the corpus callosum communicated stimuli and responses between the devil hemispheres, each specialized for different cognitive functions (1).Using a tachistoscope, Sperry delivered visual stimuli to a single visual field of the subject (1). He spy that, with the exception of olfactory stimuli, the hemispheres of the brain receive sensory stimuli and exercise motor control contralaterally (1, 3, 5).