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Touching a Nerve: The Self as Brain
by Patricia S. Churchland
W.W. Norton & Company, 2013
304 pages (Hardcover)
Source: Personal library
A pillar of most religious belief is the idea of the self as soul. There are always variations on this theme, but the immaterial side—especially in Western thought—is that which is the true you and that which makes spirituality possible. The self as soul has been assumed to be the case by theologians and most philosophers for millennia, that is until science had to go screw it all up.
In Touching a Nerve: The Self as Brain, Patricia S. Churchland, professor emerita of philosophy at the University of California, San Diego, explores the connections between science and philosophy on the issue of the brain and the mind. While combing the shelves at Brilliant Books in Traverse City, I was happy to run into this book. I recently heard Churchland on the podcast Philosophy Bites, in which she talked about neuroscience and what it means for morality. A book by her on the subject of the brain and the mind made perfect sense.
Throughout the volume, Churchland explores those various aspects of humanity that we associate with our essence—from the soul to gender identity and from aggression to war—and demonstrates how these things are connected to the brain. The conclusion is hard to miss: “My brain and I are inseparable,” writes Churchland, “I am who I am because my brain is what it is.”
She offers a great deal of evidence for the idea that I am my brain, from oxytocin in relationships to the results of split-brain patients. As to the first, what is the love between a mother and a child?
Simplified, here is how attachment and bonding works. Genes in the fetus and in the placenta make hormones that are released into the mother’s blood…This leads to a sequestering of oxytocin in neurons in the mother’s hypothalamus…. Just before the baby is born, progesterone levels drop sharply, the density of oxytocin receptors in the hypothalamus increases, and a flood of oxytocin is released from the hypothalamus. The brain is not the only target of oxytocin, however. Oxytocin is also released into the mother’s body during birth, facilitating the contractions that push the baby out. During breastfeeding, oxytocin is released in the brain of both mother and infant…. Gazing down at the infant on your breast, you feel overwhelming love and the desire to protect. Your infant gazes back, attachment deepening.
Attachment, or lack thereof, affects social behavior. Love is a brain thing and it is a good thing. Humans are unable to survive without community and so attachment is evolution’s way of making sure that mothers and fathers feel the pain of their infants and take care of them until they are able to care for themselves. An implication of this, however, is that love is not the result of an immaterial self; if it were, the brain would be an unnecessary redundancy.
Consider the idea of the self as related to split-brain patients, one of my favorite subjects when discussing the brain (see the video below). If there is anything that we now know about the brain that messes with the standards of the immaterial, undivided soul, then it is what happens after a person’s corpus callosum is divided.
In split-brain subjects, each hemisphere may separately experience the stimuli delivered exclusively to it. If, for example, a key is placed in the left hand and a ring is placed in the right hand and the subject is asked to use his hands to point to a picture of what he felt, the left hand points to a picture of a key and the right hand to a picture of a ring….Or if a visual stimulus for example, is presented to just one hemisphere, the other hemisphere knows nothing about it….Did splitting the brain split the soul?…if the brain’s hemispheres are disconnected, mental states are disconnected. Those results were a powerful support for the hypothesis that mental states are in fact states of the physical brain itself, not states of a nonphysical soul.
Churchland navigates the difficult world of neuroscience and pyschology in relationship to the self and she does so in a very accessible way. There are plenty of opportunities for a volume covering a topic of this scope to get lost in the details of which parts of the brain do what. For the novice, Churchland manages to keep these complications to a minimum and appears to be very conscientious about it. For example, she writes with an aside to the reader: “First, there is a subcortical area close to the thalamus called (sorry about this) the bed mucleus of the stria terminalis (BNST).”
Admittedly, the subject of the brain, self, neuroscience, and evolutionary psychology is a hobby horse for me (see here), but my enthusiasm for Touching a Nerve is because it is a good introduction to the subject through the eyes of a philosopher. It has all the right examples, maintaining the proper balance between the details and their significance. There is a lot to explore between the front and back covers.
The field of neuroscience and the use of the fMRI (Functional magnetic resonance imaging) are still young enough that there is much more to be discovered. What is evident is that the relationship of the brain to self is not what we humans used to think it was prior to what we know now. If my brain, when connected to another brain, can move a rat’s tail or another person’s hand (a case of “I think, therefore you are”), then can we really say that the soul is in charge? This reality has even prompted some Christian philosophers and theologians to embrace a form of Christian materialism with the hope of updating Christian thought to the discoveries of science.
Brain science, while not to the point of explaining everything yet, is creating a Copernican moment for the discussion of human nature. Like any scientific success, it has to work to survive the opportunism of hyped commercialism selling junk neuroscience and media oversimplification, but there is already a move to counter these things (see Brainfacts.org). For many these are welcomed discoveries that help to explain the world and for others it is anti-religious rhetoric. But for those who are undecided, I recommend reading Touching a Nerve, it will give your brain food for thought.