I'v gathered some links and illustrations for those of you interested in the anatomy, technique, and history of corpus collostomy--the surgery at the center of Lauren Slater's Lying.
An illustration of the Corpus callosum, from above (from David Hubel's "The Corpus Callosum and Stereopsis"). Notice how it fans out and joins the brain's two hemispheres.
LINKS
"The Corpus Callosum and Stereopsis," from David Hubel's Mind, Brain, and Vision site (Harvard Medical School)
"The Neurosurgeon's Interest in the Corpus Callosum" (a historical account) by Joseph E. Bogen (Cal Tech)
"Epilespy Surgery" (Neurosurgery at the Washington University School of Medicine)
"Splitting the Human Brain" by Paul Pietsch (Indiana University School of Optometry)
An illustration of the Corpus callosum, also from above (from Paul Pietch's "Splitting the Human Brain")