Recently, Darwinian evolutionary biologist Jerry Coyne was holding forth on split brains, arguing that “perhaps the notion of consciousness and of will are things that merely report to us after the fact the deterministic actions of our brain, and are not in any way part of a causal chain.”
Split surgery, called commissurotomy by neurosurgeons, is an operation that treats certain kinds of seizures. I’ve performed that operation myself and have taken care of the patients before and after the surgery. Beforehand, they are often incapacitated—they may have 20 or 30 seizures per day. In the surgery, we cut a portion (occasionally all) of the corpus callosum, which is a bundle of fibers that connects the two hemispheres of the brain. This procedure prevents seizures from moving across hemispheres and usually greatly reduces their severity.
What is most remarkable about these patients—what spurred Roger Sperry to do his landmark Nobel Prize-winning research—is that after the surgery they are unaffected in everyday life, except for the diminished seizures. They are one person after the surgery, as they were before. They are basically the same, even after their brain has been functionally cut in half. They feel the same, act the same, and think the same, for all intents and purposes.Michael Egnor, “Split brains are weird, but not the way you think” at Mind Matters News
So, Jerry? Jerry … ? Aw, never mind. He’ll be onto something else soon enough.
Meanwhile, if you enjoyed this piece, you may want to look at some of Dr. Egnor’s other recent articles on the immateriality of the mind:
How can mind interact with matter? Nature itself provides examples of how the immaterial interacts with the material.
Four researchers whose work sheds light on the reality of the mind The brain can be cut in half, but the intellect and will cannot, says Michael Egnor. The intellect and will are metaphysically simple
An Oxford neuroscientist explains Mind vs. Brain. Sharon Dirckx explains the fallacies of materialism and the logical and scientific strengths of dualism
What is abstract thought? A reply to Dr. Ali. Abstract thoughts cannot arise from material things because a cause cannot give what it does not have.