Unusual Brain Conditions
Some things that can happen with our brains…
Secondary Personality?
Many people believe that there is a separate personality that exists within
each hemisphere of the brain
One of these personalities is the dominant one. That is the one that controls
the way we normally behave and is the one that others see that lets them
determine what our personality traits are. The second personality must
therefore be dormant or repressed under most circumstances.
But do we ever relinquish control to this secondary personality ?
Humming tunes, Name Shouting, Dreaming
Alien Hand Syndrome
The feeling that one's hand is possessed by a force outside of ones control.
Patients retain sensation of feeling in the affected hand or arm, but lose any
sense of control over the renegade limb.
This disorder involves several parts of the brain at once, suggesting that
simultaneous damage to the parts of the brain that control movement may
be responsible.
In right-handed persons, injury to the corpus callosum can give rise to
“purposeful” movements of the left hand, while injury to the brain's frontal
lobe can trigger “grasping” and other purposeful movements in the dominant
right hand.
In other cases, “aimless movements of either hand” occur in patients
affected by injury to the brain's cerebral cortex.
More complex alien hand movements -- such as unbuttoning or tearing of
clothes -- are usually associated with brain tumours, aneurysm or stroke.
Synaesthesia
Stimulation of one sensory modality leads to realistic, vivid sensation in one
or more senses - “Union of the senses”
Rare perceptual phenomena
Greek: syn = together + aisthesis = perception
Most common: Numbers, letters, musical notation, musical sounds, days of
the week and months of the year induce Colour
Savant Syndrome
The juxtapositions of severe mental handicap and prodigious mental ability
Often associated with autism.
Normally the left side of our brain, which deals with language and
understanding, controls our consciousness --- however not in autistic people.
Kim Peek
He had an enlarged head with a gap in skull, no corpus callosum and damage
to the cerebellum.
At the age 16-20 months Kim was able to memorize every book that was read
to him. His parents moved Kim's finger along each sentence being read. Kim
would memorize a book after a single reading and having read that particular
book he would put it aside, upside down, so that no one would attempt to
read it to him again. Even today, all reading materials are placed by Kim
upside down or put backwards on a shelf.
Daniel Tammet
Many of the traits of autism but no restricted emotional and social
development - Capable of describing what, and more importantly how, he is
thinking.
Traces the changes in his brain to a series of seizures he had as a child.
He can remember 1,000 playing cards in an hour and recite them backwards
and forwards. He can tell you on what day of the week a date will fall 100
years from now. He speaks nine languages.
Asperger’s syndrome, Savant syndrome and synaesthesia
sees numbers as textured, layered landscapes in his mind.
Phantom Limb
Sometimes when a person has part of their body amputated they still “feel”
that it is there!
Oliver Sacks
The Man who Mistook his wife for a Hat
The Disembodied Lady
The Man who Fell out of Bed
Eyes Right
The President’s Speech