I googled for "brain hemispheres", and came across a few interesting links, about people who had their Corpus Collosum severed ( a few years ago, the witch doctors thought that cutting it would prevent seizures). Anyways, it seems either hemisphere is capable of providing the function of the other...maybe at a subdued level.

Personally, I believe the brain is like a radio tranceiver. We tune into certain "thought broadcasts", and likewise, we transmit. But it also has a "dis-connected auto-mode", which sadly, most people run on. :-)