Fascinating research following up Roger Sperry’s work — which showed that the mind is not split when the brain is — has confirmed and extended his findings:
Michael Egnor: There has been some absolutely intriguing work done since Sperry that I think very clearly shows the existence of an immaterial aspect of the mind. Or, at least, it shows that the mind is, in fundamental ways, not splittable; it’s not material.
The first kind was done by Justine Sergent (1950–1994), a neuroscientist working at McGill University in Canada. Sergent extended Sperry’s work in the 1980s and what she did was absolutely brilliant. (01:05:54)
She took patients who had had split brain surgery and she would show either consonants or vowels in their visual fields. She would flash a k or an a — or a p or an i — in their visual fields. And she would ask them to push a button when they saw a vowel or a consonant.
So a patient would be sitting there and she’d be flashing consonants and vowels in different visual fields. She would ask them: When you see a vowel anywhere, left or right, push a button. So she’d do it a thousand times. (01:06:28)
She understood that, in people who had had a corpus callosotomy [severing the two halves of the brain], the right visual field was connected to the right arm and the left visual field was connected to the left arm … but there was no connection between the two hemispheres (halves) that control opposite sides of the body.
So a person pushing a button with the right hand had to be pushing the button — at least from a material standpoint –- based on what the left hemisphere had seen. That is what was in the right visual field. The right hand had no way of knowing what was in the left visual field because it was a disconnected hemisphere.
She found that, if she asked them, “Whenever you see a vowel anywhere, in either hemisphere, push this button with your right hand,” the right hand would push the button. Whether the vowel was seen by the right hemisphere or the left hemisphere. Even though the hemispheres were not capable of material connection with one another. (01:07:13)
So, she said, somehow the right hand knew what it was not connected to materially. If the vowel was put in the left visual field, the right hand had no way, metaphorically, to see it. But it still knew it. That happened with the other hand too. The left hand could respond to stimuli in the right visual field, even though there was no material connection that would allow information to get to the left hand from the right visual field. (01:08:15) News, “How the split brain emphasizes the reality of the mind” at Mind Matters News
Takehome: One investigator, whose work followed up and confirmed Roger Sperry’s, called her split brain findings “perceptual disconnection with conscious unity.”
Here are transcripts and notes for the first hour and six minutes:
The brain can be split but the mind can’t. Neuroscientist Roger Sperry found that splitting the brain in half does not split consciousness in half. It just gives you a rather interesting, but very subtle set of perceptual disabilities.
Neurosurgeon Michael Egnor has split patients’ brains, while treating serious epilepsy, and the results are not at all what a materialist might expect.
How philosopher John Locke turned reality into theatre His “little theater in the mind” concept means that you can’t even know that nature exists. It may just be a movie that’s being played in front of your eyes.
Aristotle and Aquinas’s traditional philosophical approach, Michael Egnor argues, offers more assurance that we can truly perceive reality.
How did Descartes come to make such a mess of dualism? Mathematician René Descartes strictly separated mind and matter in a way that left the mind very vulnerable. After Descartes started the idea that only minds have experiences, materialist philosophers dispensed with mind, then puzzled over how matter has experiences.
What’s the best option for understanding the mind and the brain? Theories that attempt to show that the mind does not really exist clearly don’t work and never did. Neurosurgeon Michael Egnor reviews the mind-brain theories for East Meets West: Theology Unleashed. He think dualism makes the best sense of the evidence.
How we can know mental states are real?
Mental states are always “about” something; physical states are not “about” anything. Michael Egnor argues that doing science as a physicalist (a materialist) is like driving a car with the parking brake on; it’s a major impediment to science.
Why neurosurgeon Mike Egnor stopped being a materialist atheist. He found that materialism is just not working out in science. Most propositions in basic science are based on mathematics and mathematics is not a material thing.
How science points to meaning in life. The earliest philosopher of science, Aristotle, pioneered a way of understanding it. Neurosurgeon Michael Egnor talks about the four causes of the events in our world, from the material to the mind.
You may also wish to read: Why the universe itself can’t be the most fundamental thing. Atheist biology professor Jerry Coyne is mistaken in dismissing my observation that proofs of God’s existence follow the same logical structure as any other scientific theory. (Michael Egnor)