In Chapter 11, Dr. Doidge introduces us to Michelle Mack, a
29 year old who was born with only the right hemisphere of her brain. At birth,
her doctors were not aware of this and now that they do know, they only have
theories of what happened before birth. In order for Michelle to function well,
her right hemisphere had to learn the function of the left hemisphere and
economize its own function. At 29 she holds down a part time job and enjoys her
family. There are some outwards signs of her lack of a left hemisphere: bent,
twisted right hand that can be used for some things; brace on right leg; she is
a lefty and her left limbs are normal. Her right visual field is limited as she
has a hard time seeing things coming from her right. Blindness on her right
side has helped her develop an extremely keen sense of hearing. Thus she can
experience sensory overload in her hearing and touch.
During pregnancy, Michelle’s mother had some difficulties
and apparently her body was trying to miscarriage. Both mom and daughter are
happy it didn’t. Michelle’s parents began to notice things that indicated developmental
problems – vision, motor. They noticed that she was tracking visually so she
was not totally blind. Her dad noticed that she likes music and wanted to hear
certain music over and over. He had her crawl to the record player to earn
listening again. This helped develop her brain and function.
Michelle explained to Dr. Doidge that she would use rhyming,
nonsensical words when frustrated. Concrete thinking is much easier than
abstract thinking. She can play Solitaire very quickly because the decisions
are very concrete. Other, more abstract decisions are more difficult for her.
Michelle demonstrated savant abilities. She could tell what
day of the week a date was within the last 18 years by memory. For those dates
before that time, she would have to figure it out, but still could do it
quickly and accurately. Doidge told her about the work of Alexandr Luria, a
Russian neuropsychologist with a memory artist who had a photographic memory.
Also, he told her about “synesthetes” whose senses were “cross-wired” so that
they had a color code for days of the week. Michelle said she had a scene
connected with days of week.
Dr. Jordan Grafman, the chief of the Cognitive Neurosciences
section of the National Institutes of Health, National Institute of Neurological
Disorders and Stroke has been working with Michelle Mack. His background
includes working with a woman whose brain was damaged in an assault. After five
years, other doctors had given up on increasing this woman’s function. However,
Grafman began an intensive program of rehab – mind and body –and the woman’s
function increased. He also served our military personnel in Viet Nam. In this
case as well, he saw increase in function where none was expected. He
formulated a theory integrating “nondoctrinaire localization and plasticity.
His research revealed four kinds of plasticity.
1) “Map
Expansion” – neurons in the center of an area focus more on a task than the
ones on the outer limit. Different areas compete for those peripheral neurons.
The greater the demand the more likely the use for that area.
2) “Sensory
Reassignment” – When one sense is blocked, another area takes over the function
of the blocked sense. In blindness, the senses of hearing or touch develop more
and are keener.
3) “Compensatory
Masquerade” – once explained as “alternative strategies” when there is more
than one way to do something.
4) “Mirror
Region Takeover” – this occurs when a part of one hemisphere fails to do its
job, the mirror region on the other side takes over the function as well as it
can. When the damage occurs before specialization develops, function
approximates “normal” more than when it is later. P. 276 This is true for
Michelle, the damage was before birth, while her brain was being formed.
Michelle’s parents are making preparations for Michelle’s
care after they are gone, but she is pretty happy the way she is. Doidge again
introduces a person and researchers as windows into the plasticity of the
brain.
See: Doidge, N. The Brain that Changes Itself. https://www.amazon.com/Brain-That-Changes-Itself-Frontiers/dp/1501223607
Courtesy of my daughter
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