Saturday, October 02, 2010

David Weisman, M.D. - You Are Not a Unified Mind

In this post from his blog at Psychology Today, Neuro-Atheism: Grounding the soul, Dr. Weisman sets about dismantling the idea of the soul through examples from brain science.

He gives an example of brain damage, but much of what we know about mind and consciousness also reveal the multiplicity of mind - that we are multiple selves, often battling for control of consciousness (not in a dissociate identity disorder kind of way). Our brain smooths out the transitions as best as it can to create a sense of unity and cohesion.

None of this is new
- it's just that now we can use brain science and brain scans to show the same reality from different angles.
Brain tethers mind so close there is no string.

There is a common idea: our mind seems unified, so it really is. Many humans go a bit further and call that unified mind a soul. This step, from a unified self to soul, is an ancient assumption that now forms a bedrock for further religious claims, like life after death and religious morality. It is also a little god within us, mirroring and supporting the idea of a bigger God outside us. For the modern believers in the soul, let's call them soulists to avoid the opaque waters of dualism, the soul assumption appears to be the smallest of steps, so small it seems no one should question it.

Yet the soul is a claim for which there isn't any evidence, and we are right to question it. There is little evidence even for the place from which the soulists step off, the unified mind. In fact, neurology and neuroscience, working unseen over the past century, have eroded both the soul and the unified mind down to nothing. Experiences certainly do feel unified, but it is a mistake to take these feelings as reality. The way things seem isn't the way they are.

There are historical parallels. Scientists used to believe a substance called caloric made hot materials hot and flowed into colder materials to make them warmer. It seemed to be true until it turned out to be false, replaced by a better theory. Science is littered with such discredited theories with funny names like phlogiston, aether, and miasma. The soul is one of them.

Looking at the wide range of works along the axis of soulism ('Life After Death: The Evidence' by Dinesh D'Souza to ‘Absence of Mind' by Marilynne Robinson), we find little to no understanding of the brain. For example, Robinson writes, "Our religious traditions give us as the name of God two deeply mysterious words, one deeply mysterious utterance: I AM." The translation might be: Indoctrination tells us we have a soul, it feels like we are a unified little god in control of our bodies, so we are. To advance these ideas, the authors and their readers have to be almost completely unaware of twentieth century neurology and neuroscience.

If they were interested, they might learn of evidence supporting another view. Our brain creates an illusion of unity and control where there really isn't any. There are thousands of cases and experiments that demonstrate why science supports a view of the unified mind as illusion rather than reality. We'll take a single case I saw in the emergency room.

Mrs. Blanford got up from dinner with her husband, and dropped down. She could not move the left side of her body. I met Mrs. Blanford soon afterwards: her speech was normal, but she could not see objects to her left and could not move or feel her left face, arm, and leg. Mrs. Blanford was having a stroke.

An interesting thing happened when I brought her left arm up across her face so she could see it.

I ask, as I always ask such patients, "Who's arm is this?"

"That is your arm."

"Then why am I wearing your ring?" I point to her wedding band.

"That wedding band belongs on the arm of Mrs. Blanford."

"So who's arm is this?"

"That is your arm."

Some patients accuse me of stealing their rings or watches. Even if we demonstrate their arm is attached to their body, they are never convinced the arm belongs to them. At most, one is able to render them briefly confused, and then the condition reestablishes itself. The condition is called neglect and it is not at all extraordinary. Mrs. Blanford's case is not rare. When facing right brain strokes and masses the question is only what degree will the patient deny their left side.

What to make of it? How can we best explain it? Given that Mrs. Blanford had a stroke, we are best served by adopting a neurologic point of view. To do this, we need to understand a bit about how the brain works. In general, and in the broadest strokes possible, the brain is divided into two hemispheres. The left hemisphere processes speech and the motor and sensory information for the right side of the world. The right hemisphere processes nonverbal information and representations from the left side. This stroke rendered Mrs. Blanford's right hemisphere dysfunctional, no longer able to process anything from the left side of her world. It is not the left hemisphere's job to recognize the left arm, so it can't do that task. To the left brain, the left side of the body simply does not exist. The right brain has failed, not only to process arm information, but failed to let the left hemisphere know it failed (one thinks of the Bush White House).

It isn't only that her left brain can't do the right brain's task. The left hemisphere also can't recognize that there is missing data, or that there is something wrong with the data. It has to use the data it has, so the left hemisphere comes up with something called a confabulation, creating a verbal fabrication to explain missing information. In this case the confabulation becomes, "That is your arm." Although nonsense and easy to falsify, the idea is internally consistent, makes some sense of the (messed up) internal data, and feels right. The injured brain creates a confabulation to maintain unity of self and a feeling of control. We find a brain believing something that seems right, but isn't (again).

A neglect case only makes sense if you consider each hemisphere as its own separate entity. We see that when a stroke damages the brain, the mind follows--as a result. It is expected, like unplugging a mouse from the computer results in no curser movement.

Now consider yourself. Consider your own left arm. It feels perfect, under your control, a part of you, exactly where it should be. But this unified perception relies on neuronal machinery humming along under the surface. Your sense of unity, only perceptible to you, is a sheen on the surface, not a layer of reality.

Where does this leave the soul? Does the soul make any sense in the face of a brain and mind so easily fractured by ischemia? A soul is immaterial, eternal, a little god, impervious to injury, able to survive our deaths. Yet here we see one injured, tethered so close to the injured brain that there is no string. We see a hole in the brain, a hole in the soul, and through it we get a glimpse into the brain's inner workings. One part is damaged; another part falsely thinks it is whole and unified. How does the idea of a unified soul make one bit of sense in the face of this data?

The soul is an ancient hypothesis, older than caloric and just as false, falsified not only by a single case of neglect, but by the collected works of neurology and neuroscience. This leaves a distinct absence of soul, by whatever name. It does not leave the absence because of cultural biases and inertias, or because of overarching dogmas and hidden agendas and wishful thinking. It leaves an absence because neuroscientific data support it and tend to falsify everything else.

We gave Mrs. Blanford the treatment for stroke, tPA, almost one hour after symptom onset and less than 50 minutes from the time she came to the ER. It was close to my personal best treatment time. We also enrolled her into a stroke trial, and ensured that medical science took another tiny step forward. Perhaps it was because of our treatments, or perhaps because of her personal biologic fate, Mrs. Blanford did incredibly well. She walked out of our hospital about a week later, appearing nearly whole. She felt unified with her body and her mind, even though some of us know better: that reconnection isn't unification and that the way things seem isn't the way they are.

No comments: