Brain Bisection and Personal Identity

Roland Puccetti, The British Journal for the Philosophy of Science, December 1973, 24, 4, 339–355.

Excerpt: It is customary to think of a human being as having a single brain, possessing a unitary mind, constituting a unique individual person. However recent studies of patients whose cerebral commissures have been sectioned to prevent interhemispheric spread of epileptic seizures suggest a very different state of affairs.

The operation is relativley simple in conception, if not in execution. Both a frontal and a posterior opening are made in the top of the skull, followed by mid-line sectioning of the corpus callosum, and anterior and hippocampal commissures, and in some cases the massa intermedia as well. Upon recovery these patients appear to function just about as well in ordinary situations as before the operation, except for some loss of short term memory. …