Thursday, April 29, 2010

Mind, body and brain

By Steve Rensberry

The human brain interacts with the body by way of a complex network appropriately called the central nervous system. This itself is composed of functional units such as the brain stem, spinal cord and the matter which makes up the brain itself. Other functional units: the limbic system - associated with such things as anxiety - and the motor system - associated with such things as speech.

A series of membranes lying just under the skull effectively creates a blood-brain barrier that allows only a restricted range of substances to pass through to the brain. Beginning with the brain, the central nervous system extends through the brain stem, through the spinal cord and through a series of ganglia and peripheral nerves branching out throughout the body. The peripheral nervous system consists of nerves and nerve roots. The anatomic nervous system controls such things as heart beat and digestive processes.

Large bundles of nerves or conduits, themselves composed of millions of nerve cells and neurons, exist to help the brain communicate with other parts of the body. Scientists have identified more than 200 neurotransmitters.

The brain's primary source of energy is blood glucose. Also important are those nutrients which are necessary for the metabolism of glucose, such as magnesium, pantothenic acid, biotin, thiamine, riboflavin, niacin and chromium. Vitamins B12 and B6, protein, copper, zinc, folacin and iron are believed to be essential in the creation of red blood cells, which are responsible for delivering oxygen to the brain. Other nutrients, such as potassium, assist in the transmission of nerve impulses.

What evidence is there that the human mind is anything more than a product of this complex, multi-functional physical organ we call the brain? Can the totality of mental phenomenon be adequately explained as a product of purely non-personal, physical and chemical processes? Can the conscious mind exist apart from what is generally understood to be the brain?

On my way to positing a theory, let me first note the following:

- At no time in human history has any human being ever been shown to have thoughts after their brain is removed or after it is denied oxygen for more than but a very few minutes. They have, however, been shown to have a very high propensity to decay, with barely the slightest sign of reconstitution.

- Split brain studies undertaken by Michael Gazzaniga, Roger Sperry and Joseph Bogen at the California Institute of Technology several years ago revealed striking differences between the two hemispheres, with the left brain (responsible for such things as invention and interpretation) appearing to have a substantially higher degree of consciousness than the right (responsible for such things as emotion, subconscious processes, vision and pattern recognition.) Dr. Robert Buckman, who wrote "Can We Be Good Without God? Behaviour, Belonging and the Need to Believe," points to brain research as suggesting that "supernatural experiences" are a uniquely right temporal lobe phenomenon.

- Dr. Paul MacLean, a researcher with the National Institute of Mental Health, suggests that conflict arises among the three, fundamentally distinct types of brains we all have, one being the reptilian brain centered in the brain stem and associated body organs; another being the mammalian brain, central to learning and memory; and the other being the primate brain centered in the frontal lobes and responsible for intellectual theorizing, higher reasoning and experimentation. The urges and needs of each are not always aligned.

-  The classic 1902 book, "The Varieties of Religious Experience," by William James argues that all humans share impulses belonging to one of two types: lower level, instinct-based impulses, and those involving higher, more cognitive processes. James claims that these two types of impulses, acting together, is what gives rise to religious experience. You'll note the assumption on my part that so-called religious experience or all experiences of the supernatural for that matter, are tied in some way to some measure of philosophical and metaphysical dualism, in the belief that a person's mind is a separate and living entity set completely apart from the physical brain within our skulls.

- While working on his doctorate in 2003 at the University of Illinois at Champaign-Urbana, Clinical Psychologist Ben Hidalgo wrote a thesis entitled "The Utility of a Neuropsychological of Religious Experience." Included in the piece is a composite definition of religious experience, in which Hidalgo cites works by William James, Walter N. Pahnke, Roland Fischer and James B. Pratt.  See:  I quote:

"These characteristics can be present in any combination to identify a religious experience and have each been verified as characteristic of a religious experience through observation and self report. Together they address all known cultural expressions of religion."

He lists these characteristics: 1) Loss of awareness of discrete limited being, passage of time. 2) Obliteration of self-other dichotomy. 3) Visual, auditory hallucinations. 4) Feelings of bliss, ecstasy, transcendence, internal unity, cosmic union and consciousness, transcendence of space and time. 5) Sense of presence of a higher being or reality. 6) Sense of insight into the very nature of the universe. 7) Trance states. 8) Sense of sacredness. 9) Sense of ineffability. 10) A preoccupation with ritual.

- A growing body of evidence exists showing the two-way relationship between a person's mind and body. The body, using a variety of biochemical substances, can affect an individual's mood, attractions, appetite, alertness, and overall state of mind. Physical activity is known to cause the release of endorphins, working against feelings of depression and anger. Do we think about things such as intimacy with a loved one because the chemical in our bodies prompt us to, or do our hearts beat faster and our bodies become aroused because we tell them to? What I read seems to suggests that it's a bit of both.

- The placebo affect, as it relates to both mental and physical health, is well documented. Believe you took an antidepressant, and the sugar-pill you took may just have an effect on par with that high-powered pharmaceutical. Allow yourself to be convinced that a simple sugar-filled capsule contains a powerful narcotic and will eliminate your pain, and in some cases it does just that. Why? Because while our brains have the ability to direct the actions of our body at the same time that the body works its magic directly upon our brains using such biochemicals as endorphins, bombesin and vasopressin.

There's certainly something to be said for the feeling that some sort of dualism is at play within the universe and the mind in particular. Mental phenomenon can be exceedingly bizarre, throwing us into a world of self reflection and contemplation, unlimited by time and space, tradition or conventions, allowing us to conceptualize and  move nearly seamlessly from image to emotion to desire to conviction to deep, abstract analysis on a level unmatched anywhere else on earth. Humans are exceedingly unique and unusual. Plato described the body as a prison for the soul. Death preceded the life we live, therefore life must follow again once we die, he says. Sacrates argues for a soul that exists prior to birth because of what we appear to know almost instinctively upon birth. The invisible (Forms) outlasts the visible, thus the soul (mind) must outlast the body, he reasons. Hume, Locke, Descartes and many others have all weighed in on the issue of mind and dualism, but a good summation of the common flaw among those who believe in some sort of dualism, that mind can exist apart from the brain, was given by Nagel.

An entry on Dualism and Mind in the "Internet Encyclopedia of Philosophy" (Problems with Leibniz's Law Arguments for Dualism, (see written by Scott Calef, reads:

"Although each of these arguments for dualism may be criticized individually, they are typically thought to share a common flaw: they assume that because some aspect of mental states, such as privacy, internationality, truth, or meaning cannot be attributed to physical substances, they must be attributable to non-physical substances. But if we do not understand how such states and their properties can be generated by the central nervous system, we are no closer to understanding how they might be produced by minds . . . . Dualists cannot explain the mechanisms by which souls generate meaning, truth, internationality or self-awareness. Thus, dualism creates no explanatory advantage. As such, we should use Ockham’s razor to shave off the spiritual substance, because we ought not to multiply entities beyond what is necessary to explain the phenomena. Descartes’ prodigious doubt notwithstanding, we have excellent reasons for thinking that bodies exist. If the only reasons for supposing that non-physical minds exist are the phenomena of internationality, privacy and the like, then dualism unnecessarily complicates the metaphysics of personhood."

My take on it: Creativity, the ability to shape and suspend belief, to imagine, to dream, to rationalize and establish meaning on a purely subjective level, is one of the single most powerful human faculties that makes us who we are, that sets us above and beyond every other known creature on the planet, giving us a deciding advantage in particular when working in groups and in social formations. But almost by default it is a faculty without limits. The feeling of dualism, of a mind or soul that is categorically distinct from our flesh and blood bodies is thus, fundamentally, a matter of simply failing (or deciding not) to apply the brakes. We suspend belief in a naturalistic universe in the hopes that we are right, because we want desperately to be right. We imagine, pray, dream and desire to be unrestrained by the limitations of the human condition, willfully allowing ourselves to be sucked into rationalizing the existence of that which does not exist. Meaning and value are no less important to the good life, whether you presuppose they come from an invisible realm shared by mind and spirit, or from a singular earthly realm shared by neurons and synapse gaps. But there's pleasure in believing the magical realm is real, an evolutionary advantage perhaps .... in imagining a world beyond our own, in throwing the entire weight of one's cognitive devotion into a whole-hearted belief in the paranormal or the supernatural and the presumed permanence that comes with it.

Carl Sagan on God, Faith and Religion