{=page1} CORPUS CALLOSUM

The secret to understanding the split brain research is to \
understand that each of our eyes has a left and a right {:VISUAL FIELD}.  \
It is not correct to say that information from the left eye feeds \
into the right brain and vice versa.  Rather, it \
is correct to say that information from the right visual \
field of both eyes will be sent directly to the \
left {:CEREBRAL HEMISPHERE}, and information from the \
left visual field of both eyes will be directly sent to \
the right cerebral hemisphere.

{=page2} The {:OPTIC NERVE} which sends visual information from \
the {:RETINA} to the {:OCCIPITAL LOBES} is both crossed and \
uncrossed.  The place where the {:AXONS} of the optic nerve cross \
is called the {:OPTIC CHIASM}.

{=page3} Information from the left visual field crosses to the opposite \
side of the retina and then is sent to the right {:VISUAL CORTEX} of the \
occipital lobe.  (There is an intervening {:SYNAPSE} in the {:THALAMUS}, \
but we don't need to be conceed with this here.)  So the right cortex gets \
direct visual information from the left visual fields of both eyes.

{=page4} Conversely, information appearing in the right visual field of \
both eyes stimulates the opposite side of the retina and then in sent to \
the left {:VISUAL CORTEX} of the occipital lobe.

{=page5} Because you and I have a functioning {:CORPUS CALLOSUM}, \
information about the experiences of the right {:CORTEX} will be \
transmitted to the left cortex. The corpus callosum is a \
{:TRACT} (or bundle of {:AXONS}) that connect cell bodies in the right \
cortex with the left cortex and vice versa.  Because of the corpus \
callosum, each cortex will intimately know about the experiences, \
wishes, thoughts, etc., of the other cortex.