dyslectic person is using his right hemisphere instead of
his left to read and spell.
The two most important contributers to dyslexia are an underutilized
an out-of-whack central bridge of tissue in the brain, called
the corpus callosum. (The
bibliography contains technical details from some of the brain-scan
research which has documented these two problems.) But why
does it matter which side of the brain you use? Because the
left-hemisphere is programmed to do the things you need for
reading and the right is not.
a letter with its sound,
information that comes into your brain in strings, like
the sounds in a word - one letter after the other, rather
than seeing a word as a single picture,
a word into its individual sounds, and
grammar and syntax.
hemisphere is different. It deals in areas and space and patterns.
It doesn't understand parts of speech, or keep track of letter-order
in spelling. It "reads" a word as a line drawing that it has
been taught has a meaning, -- a sketch, not a line up of sounds.
So if it sees this:
that these "drawings" represent a place where somebody lives.
But it is just as apt to say home or residence (or igloo or
tepee) as house. You can see that if the left side leaves
the reading to the right side, the result can come out scrambled
the corpus callosum, it
is a bridge of nerve cells over which information from one
side of the brain gets to the other. Everything you see or
hear goes to both sides, but each side has it own specialty.
The corpus callosum not only transfers information, it helps
decide which is the appropriate side, and sends it there.
Obviously a wimpy CC may not deliver language tasks to the
left where they belong. On top of that, it transmits slowly,
so part of the information arrives out of sync with the rest. (See the "Jigsaw Puzzle")
if all that weren't enough, the language areas in the
dyslectic brain tend to be smaller than they are in a
standard brain. Now you take a wimpy corpus callosum,
an over eager right-hemisphere, and an undersized left
language area, and you have the recipe for trouble.