The Case Against Reality -1
A chapter wise summary of the book "The Case Against Reality" by Donald Hoffman
THE SPLIT- BRAIN SURGERY
In 1962, Joseph Bogena and Philip Vogel sliced in half the brain of Bill Jenkins. Bill Jenkins was a patient who underwent a pioneering surgical procedure in 1962 by neurosurgeons James Bogen and Philip Vogel. Mr. Jenkins had been plagued by the seizures. The convulsions grew so intractable that he lived in a perpetual fog, unable to think clearly or function normally. Medicinal remedies had failed, leaving him increasingly disabled and despondent. Desperate for an answer, doctors James Bogen and Philip Vogel conceived a radical surgical plan. They would cut the neural fibers comprising Jenkins' corpus callosum — the trunk-like bundle connecting the two hemispheres of his brain.
The brain is divided into two hemispheres, left and right. Each hemisphere has 43 billion neurons. Their axons subdivide, like branches of a tree, to allow trillions of links among them. But, in contrast to the rich interconnections within a hemisphere, the bond between hemispheres is a tiny cable, the corpus callosum, with just over 200 million axons. Bogen and Vogel planned on severing this connection. The hope was that severing this physical bridge would prevent seizures from spreading from one half of the brain to the other.
On the face of it the surgery was successful. Bill Jenkins didn’t suffer from any more drop attacks, and just two general convulsions in the next ten years. But there were some interesting side-effects, which we will come to later on.
THE SEARCH FOR A SCIENTIFIC THEORY OF CONSCIOUSNESS
Donald Hoffman was part of the Helmholtz club at UC Irvine. The purpose of the club was to explore how advances in neuroscience might spawn a scientific theory of consciousness.
They were interested in questions like the ones below:
What kind of creature are you? How is your body related to your conscious experiences and propositional attitudes? How is your experience of a chai latte related to activities in your brain? Are you just a biochemical machine? If so, how does your brain give rise to your conscious experiences? The question is deeply personal and, as it happens, deeply mysterious.
A special 2005 issue of the journal Science ranked the top 125 open questions in science. The runner-up was: What is the biological basis of consciousness? This is the question that the Helmholtz Club pursued. If you read the question carefully, there is an assumption. It is looking for a “biological basis” of consciousness. To be precise, the scientists were expecting to find a “Neural Origin” for consciousness.
It reveals the kind of answer that most researchers expect—that there is a biological basis for consciousness, that consciousness is somehow caused by, or arises from, or is identical to, certain kinds of biological processes. Given this assumption, the goal is to find the biological basis and describe how consciousness arises from it.
And there was a reason why scientists had this assumption. For a long time, there was a debate between biologists and vitalists over what distinguishes living from non-living systems. Vitalists believed there must be some non-physical, vital force or "élan vital" that gives life, which could not be explained purely by physical mechanisms and ingredients. However, this vitalist view was proven wrong by the 1953 discovery of the double helix structure of DNA by Watson and Crick. This showed that the genetic code and ability to replicate, the essentials of life, could arise mechanistically from just physical/chemical components organized into the DNA molecule. This victory of the physicalist, mechanistic explanation over vitalism allowed molecular biology to unite with evolutionary theory to comprehensively understand life's origin, evolution over billions of years, and opened the way to redesign living systems through genetic technologies - all from the basis of physical principles without need for any non-physical vital forces. The DNA discovery decisively settled the centuries-old debate in favour of a fully physical, not vitalist, account of what makes something alive.
Inspired by this victory, the members of the Helmholtz club expected that eventually there would be a mechanistic explanation provided by neuroscience that would explain consciousness. And so, scientists began looking for the Neural Correlates of Consciousness (NCC).
Many experiments hunt for correlations between neural activity and consciousness, expecting that as the hunt succeeds, as the list of correlations grows, a critical discovery will solve the mystery of consciousness, just as the double helix solved the mystery of life.
INTERESTING FINDINGS FROM EXPERIMENTS DONE ON SPLIT BRAIN PATIENTS
Coming back to the split-brain operations. Roger W. Sperry was a neuroscientist who conducted extensive research on split-brain patients in the 1960s and 1970s. He won the Nobel Prize in 1981 for his work.
Paul Gazzaniga is another scientist wo worked on split brain patients. Here, I’ll describe his results.
Here are some facts about our body: The left hemisphere of our brain controls the right side of our body and the right hemisphere of the brain controls the left side of our body. So, information processed by the left eye enters the right side of our brain and vice versa. Also, Left brain contains the speech center.
When a patient was shown an object only to its left visual field, and then was asked what they were looking at, they were unable to say it. Because the information acquired by the left visual field went to the right hemisphere, and the speech center is in the left hemisphere. And because their corpus callosum was severed, there was no communication between the two hemispheres. But if they were asked to write the name of the object with their left hand, they could correctly write what image they were seeing, because the information entered the right hemisphere and the right hemisphere controls the left hand. Now if you show what the patient had written to the right visual field and ask them why they had written that name, if they hadn’t seen it, they would either say “I don’t know” or they would come up with a story to justify why they wrote that name.
From the outcomes of these experiments, it seems like there are 2 conscious entities that reside within our brain. So far there are no definitive explanation for this behaviour.
The outcomes of these experiments on split-brain patients leads us to ask some profound questions about our identity and being:
What kind of creatures are we that our beliefs, desires, personalities, and perhaps the destinies of our souls can be split with a scalpel? Why are we conscious? What is consciousness? Can neuroscience decipher the perennial mystery of human consciousness? The searchlight of science, which has revealed insights into the realm of the impersonal—black holes, bound quarks, slow tectonic plates—is now being directed toward what matters to us most: our deeply personal world of conscious beliefs, desires, emotions, and sensory experiences. Might we glimpse and even comprehend our very selves? This is an aspiration of the science of consciousness.
SEARCHING FOR THE NEURAL CORRELATES OF CONSCIOUSNESS
The objective of Neural Correlates of Consciousness is to hunt for correlations between neural activity and consciousness, expecting that as the hunt succeeds, as the list of correlations grows, a critical discovery will solve the mystery of consciousness, just as the double helix solved the mystery of life.
Here’s the rationale behind hunting for Neural Correlates of Consciousness. If we want a theory that links neurons and consciousness, and we have no plausible ideas, then we can start by looking for correlations between them. Inspecting these correlations, we might discover a pattern that turns on a conceptual lightbulb.
We know that specific activities of the brain correlate with specific conscious (and unconscious) mental states…… for instance, activity in area V4 of the temporal lobe correlates with conscious experiences of color.10 A stroke in V4 of the left hemisphere leads the patient to lose color in the right half of the visual world, a condition known as hemi-achromatopsia. If the patient stares, say, at the middle of a red apple, then the left half of the apple looks red and the right half looks gray. If, instead, a stroke damages area V4 in the right hemisphere, then the right half of the apple looks red and the left half looks gray. Normal person can enter briefly into the color world of the hemi-achromatopsic via transcranial magnetic stimulation (TMS). TMS is induced by a strong magnet placed near the scalp, whose magnetic field is set either to enhance or impair activity in regions of the brain nearby. If TMS impairs activity of V4 in the left hemisphere, then, as the person watches, color drains from the right half of the world: if they look directly at a red apple, the right half of the apple fades to gray.11 Turn off the TMS, and red color seeps back into the right half of the apple. If TMS stimulates V4, then the person will hallucinate “chromatophenes”—colored rings and halos.12 With TMS, you can pour colors into consciousness, or siphon them out of consciousness.
But for all the work done in NCC, it still hasn’t been able to explain consciousness. NCC has found correlation between brain activities and conscious experience, but it hasn’t been able to explain the CAUSE. How does a specific brain activity cause a particular conscious experience, and not something other? NCC provides no description of the mechanism that can explain the causation. It only measures the correlation. So NCC didn’t bring us closer to a scientific theory of consciousness.
What do we want in a scientific theory of consciousness? Consider the case of tasting chocolate versus hearing a siren. For a theory that proposes that brain activity causes conscious experiences, we want mathematical laws or principles that state precisely which brain activities cause the conscious experience of tasting chocolate, precisely why this activity does not cause the experience of, say, hearing a siren, and precisely how this activity must change to transform the experience from tasting basil to, say, tasting rosemary. These laws or principles must apply across species, or else explain precisely why different species require different laws. No such laws, indeed no plausible ideas, have ever been proposed.
A DIFFERENT WAY OF LOOKING AT THE PROBLEM
Perhaps we haven’t found the crucial experiment that unveils the breakthrough idea, and eventually someone will come up with it and we will finally have a theory of consciousness.
Or maybe we are limited by our own intellect. Just like cats can’t comprehend calculus or quantum theory, the human intellect simply isn’t evolved enough to tackle the problem of coming up with a scientific theory of consciousness.
BUT there might be a third possibility: perhaps we DO possess the necessary intelligence, but instead are hindered by a false belief.
So, what is this false belief that’s holding us back? Donald Hoffman proposes this: “We see reality as it is.”
As per evolution by natural selection, Donald Hoffman states that we do not see reality as it is.
….. evolution by natural selection entails a counterintuitive theorem: the probability is zero that we see reality as it is. This theorem applies not just to taste, odor, and color, but also to shape, position, mass, and velocity—even to space and time. We see none of reality as it is.
Hoffman proves this statement (along with mathematician Chetan Prakash) through the mathematics of probability by formulating a theorem named Fitness Beats Truth Theorem, aka the FBT Theorem.
Hoffman proposes that if we are to come up with a theory of consciousness that provides us with mathematical laws or principles that state precisely how we feel/ experience a specific conscious experience, we have to discard space-time itself. That is, get rid of the assumption that space time exists as an objective reality independent of the observer.
In the upcoming essays, we will go into the details that justifies this stance.