Information presented about commissurotomy and temporal lobe epilepsy
and other neuroscience facts are accurate to the best of my ability
to explain.  Well, except the part about people splitting into
different entities.  If you needed me to tell you that, Dr. Flannery
has a wing for you, too. 

Massachusetts General is a real hospital that still performs 
commissurotomies to this day, although infrequently, and only in
extreme cases is the corpus callosum completely severed.  The 
procedure is performed in an actual place called Epilepsy Surgery Unit;
however, the internal geography of the hospital is entirely fictional.

Fenboro is fictional, but other Massachusetts placenames are not.
There is no Massachusetts Institute of Mental Health.

For more information on the split brain procedure and its non-fictional
after-effects, visit your local library.  Or these web sites (but your
library could probably use the late fees):

http://design.otago.ac.nz:801/grant/psyc/TWOBRAIN.HTML
http://www.macalester.edu/~psych/whathap/UBNRP/Split_Brain/Pioneers.html
http://neurosurgery.mgh.harvard.edu/ep-sxtre.htm

--nev
  http://members.tripod.com/nevdull/