a test for the corpus callosum.
If you touch someone lightly on the inside of his fingers
with his hand behind his back where he can't see what you
did, and then you ask him to show you on the other hand where
he was touched, that information has to go through our old
friend, the CC.
is fully matured by about ten years old, so no adult
should make more than one or two mistakes on this. If you
find someone with reading problems who is intelligent, makes
mistakes on the rnisspelled homophones and blows the tactile
localization test, you are as sure as you are going to get
in this world that you are looking at dyslexia.
is how you do it:
child's paint brush ready for light touching. Imagine the
finger broken into three sections called "pads"
separated by the joints. The three sections are the
fleshy parts of the finger. You will touch either the far
pad (fingerprint area) or the near pad next to his palm (never
the middle one.) Have your friend hold out both his
hands, palms up, fingers spread out, one in front of him and
one behind. Explain that you will be touching the fingers
on the hand behind him where he can't see it. He is
to point with his thumb on his front hand to where you touched
him. Hold out your own hand, touch one of your fingers, and
ask him where he would point on his own hand. Do this with
several spots on both the inside and the outside joints of
your fingers until you know he has the idea and never tries
to touch that middle joint. Warn him that when you have touched
the hand behind him, he
is NOT to wiggle those fingers at all.
him twice on each location on each finger, skipping around,
of course, making a total of 16 touches, four to a finger,
on each hand. Make sure
your touches are light and quick!
Mark on your diagram
of the hands, the spot where you touched him. If he identified
it right, make an 0, if he pointed to the wrong spot, make
an X. If he makes two or more errors, his CC is not transferring
information from one hemisphere to the other quickly and accurately.