LIFE LINES 33

HOW NEURONS CREATE OUR MINDS


For most of the time we have existed as a species we have been self-aware and know that each person has a unique personality and sense of self. We call that self our mind. In some religious traditions that self is also identified with the soul, but other theologians have distinguished the mind and the soul. We know that a baby’s mind develops and we are not the same person at 25 as we were when we were 2. For that matter, if we live into our 80s or 90s we may find our minds are not what they were in our 30s, and we tend to forget and our skills diminish. We prefer a soul (if we believe there is a survival of the self after death) that is at its peak of efficiency, not at its state in premature death (an infant, for example) or in senescence with a severely impaired mental awareness.

Things changed after the cell theory showed a variety of tissues existed. Our brain is composed of neurons, about 100 billion of them. Studies of injuries or strokes revealed that the brain has regions specific to vision, hearing, judgment, emotions, control over our limbs, memory, learning, association, and other functions. These set aside neurons in specific regions of the brain are stimulated by nerve impulses brought by our peripheral nerves or sense organs and they cause neurons in the brain receiving the signals to form synapses or fusions of nerve fibers between the incoming nerves and the regional neurons receiving the signals. The more the region is stimulated by signals, the more the fibers connect and form permanent or long–lasting associations. This was first discovered by a Canadian psychologist, Donald Hebb. And the easy way students learn it is “neurons that fire together, wire together” Neurobiologists have learned how a stimulus travels along a nerve, what chemicals are released to stimulate the wiring of synapses, and what happens if a limb is amputated or we lose one of our senses (like sight or hearing). From these twentieth century findings, neurobiologists have learned how opiates and other painkillers work and how some chemicals produce feelings of elation or peace in a troubled individual. It has led to a shift in psychiatry from “talk therapy” for psychotics to chemical control of those centers of the brain that are functioning abnormally in the psychotic. It also has taught psychiatrists how some illegal (i.e., controlled) substances lead to addiction and behavioral changes. For many neurobiologists the mind or self is a creation of our neurons and unique to just our life and will die with us, surviving only in a metaphorical or historical sense through our writings or other creations and the lives we have touched.

Some people are troubled by that scientific assessment. I am not. I cherish my uniqueness and protect it from harm. When I studied the genetic effects of LSD at UCLA, I used Sandoz LSD supplied by the National Institute of Mental Health, and found it was not mutagenic and did not break chromosomes and did not lead to chromosome loss. Despite my access to the LSD I never tried it on myself. It was not a lack of curiosity, it was my belief that my mind is a product of my neurons and if I chemically alter or damage them, I am taking a risk, especially since my mother was a paranoid schizophrenic. Since I shared half her genes, I did not want to test the expression of them under conditions where I had no control and no certain knowledge of those risks. I much prefer being guided by science than by luck.