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Left Hemisphere / Right Hemisphere
"The great pleasure and feeling in my right brain is more than my left brain can find the words to tell you." - Roger Sperry.
Science has long known that different hemispheres of the brain control or are in charge of specific types of functions. Left brain has long been associated with language and cognition; right brain with intuition, style, and feeling. In some ways the right hemisphere has been maligned. Karl Popper and John Eccles, authors of The Self and Its Brain, described the brain's right hemisphere as the "minor brain".
But as researchers delve deeper into brain function and discover the remarkable people who turn all of the well established notions upside down, what is "known" about brain science is often a great deal less than what is unknown.
“When someone says they are right or left-brain it’s really just a metaphor for a cognitive style”, says neuropsychologist Professor Michael Saling from the University of Melbourne. “Without a doubt the popular left and right division of the brain is an over-simplification. "For example, research is showing that musical, artistic and intuitive thinking can’t be thought of as strictly ... or exclusively of the right hemisphere ".
At three years of age, Nico of Spain, was about to undergo a hemispherectomy*. He was having close to one hundred epileptic seizures a day. The right hemisphere was the source of the trouble and surgeons, in an attempt to save his life, removed it.
He is now epilepsy-free, has many friends, and with the help of a computer he is powering through school. Nico demonstrates a high IQ and possesses exceptional language skills for his age. Speech and language are understood to be primarily capacities of the left brain.
He also has difficulty controlling the left side of his body and he cannot see out of his left eye. After all, the visual cortex is missing for his left eye. Beyond this it is impossible to tell that Nico has only half of his brain.
"In a neurophysiological sense Nico had been forced to develop a new brain, a new hemisphere, in his first three years of life", writes Battro. "...Nico is a normal child. Only his brain images remind (us) of his brain condition…he has a well kept secret in his skull". Only time will tell if the missing hemisphere will present a problem, but his prognosis is very promising. He does not seem to need his right hemisphere.
* Removal of one hemisphere of the brain.
Michelle Mack's Story
Michelle Mack lost half her brain while still in the womb. As far as anyone knows Michelle had a stroke while still a developing fetus; her left hemisphere never fully developed, though there are tiny fragments of it there.
Normally the left hemisphere is thought to control language processing and verbalization and by that model Michelle should not be able to speak. But she does, and quite well at that.
Michelle has very obvious problems controlling the right side of her body, but little else seems to be wrong with her. In fact she helps her mother, a pastor, with sorting and organizing church records. "I take them home and I update them on my computer at home and I bring them back to my mother and I file them." said Michelle.
Out of concern for her future, Michelle's mother contacted the National Institute of Health and mother and daughter visit the institute about once a month. They are trying to determine just how Michelle's brain copes with a very different workload than is typical of a complete brain.
On a recent visit Michelle's mom revealed that she had an interesting talent. If you told Michelle a date she could tell what day of the week that date occurred on.
On the flip side she lacks a particular talent that would normally be associated with left brain. She has a great deal of difficulty with spatial organization and ideation. The thinking is that so much of Michelle's brain has been (self) rewired to take the place of the missing hemisphere that there is "no room" for the usual spatial functions.
The "Unfortunate" Story of Phineas Gage
On September 13, 1848, Phineas Gage was a railroad construction foreman in charge of blasting gang on the Rutland & Burlington Railroad outside the town of Cavendish, Vermont. After an assistant drilled a hole in a large granite rock, added gunpowder, and sand (the sand may have been omitted by accident), Gage was to add a fuse, and tamp the mixture down just prior to blasting. Gage was standing (or sitting [accounts vary]) and was momentarily distracted. No witness was able to state what the distraction was. The tamper slipped from Gage's hand and fell into the hole. A spark from the granite ignited the powder and it exploded sending the iron rod (see photograph) flying. It entered the left side of his face, shattered his upper jaw, passed behind his left eye, and out the top of his head. The rod ended up roughly eighty feet away and Phineas seemed none the worse for the accident. He spoke to coworkers and walked under his own power to a cart that took him the three quarters of a mile to town.
Dr. Edward H. Williams examined Phineas and stated that "I first noticed the wound upon the head before I alighted from my carriage, the pulsations of the brain being very distinct. Mr. Gage, during the time I was examining this wound, was relating the manner in which he was injured to the bystanders. I did not believe Mr. Gage's statement at that time, but thought he was deceived. Mr. Gage persisted in saying that the bar went through his head....Mr. G. got up and vomited; the effort of vomiting pressed out about half a teacupful of the brain, which fell upon the floor."
Dr. John Martin Harlow was the next physician to see him. Phineas underwent a long recovery with possibly two infections, one of which left him in delirium, but by April 1849 he seemed to have completely recovered. However, according to a medical paper written two decades later, friends reported that he could no longer control his emotions or temper and some even went so far as to say Phineas was no longer "Phineas."
In 18681 Dr. Harlow wrote: "The equilibrium or balance, so to speak, between his intellectual faculties and animal propensities, seems to have been destroyed. He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. A child in his intellectual capacity and manifestations, he has the animal passions of a strong man. Previous to his injury, although untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart businessman, very energetic and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was 'no longer Gage."
It is known that Gage took advantage of his notoriety and appeared at P.T. Barnum's American Museum. Later in life Gage took a job in Chile as a long distance coach driver for seven years. Prior to that at a livery in San Francisco for a year and a half. This indicates that Gage somehow recovered from all of the injuries and lived a socially adjusted, normal life.
This was the case that bolstered the idea that separate areas of the brain controlled distinct thought processes. Yet, what is written about it may largely be conjecture based on almost no actual research of first hand accounts.
1That Dr. Harlow wrote negatively of Gage twenty years after the accident is taken with a great deal of skepticism by researchers today. First, because twenty years later Harlow had no contact with Gage as he'd been dead nine years. Second, because Gage obviously had employment that only a fully functioning person could obtain. Dr. Harlow also promoted the concept of phrenology; a "science" that could determine a personality from bumps on the head.
This is the third in a series of articles discussing the new field of research called "Brain Plasticity."
Brain Plasticity Science
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