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12/3/12

Michael Gazzaniga: The Mind's Past

Bookmark and Share In The Mind's Past, Gazzaniga reminds me of age-old teachings in Buddhism and Advaita. Of course in this he is not out of tune with other neuroscientists.   I am reminded of Benjamin Libet,  I am also reminded of neurophilosopher Thomas Metzinger, who publishes opinions reminiscent of ancient Eastern views of self and mind. (Not that neurophilosphers intend it, although some borrow from the teachings without acknowledging their sources.) Neuroscience also provides evidence that corroborates some of the teachings.

The essential Eastern teachings focus on everyday life rather than mystical experiences, which come and go. As a single tenet, they tell us that the ego/self is an illusory fabric to be seen through and that there is no character narrating a life story. They go further than Gazzaniga and other researchers/thinkers, but at least in this there is a kind of accord.

As for Libet, his research-findings against free will are famous. Still, I cannot go that far, either for him, or for the East. My view is that the Eastern teachings do not account for a different understanding of self and free will, which holds that decisions are made and we feel ourselves making them. Absent from Libet's study was any actual decision-making. Subjects had only a yes or no to muscle response and no election between various options. The yes or no: Libet pointed out that his subjects could always veto an act.  Fact is, decisions are made between various options, not just a yes or no.  Libet's research does not nail a lid on the coffin of "agency."

As for free will itself, the question becomes, Free from what? The question is a non-starter, not answerable with empirical data, and the empirical question is, How do we make decisions? (I say this while I know that real questions are not always just empirical.)
 
Gazzaniga's thesis is that we are puppets controlled by our brains. Our brains are clever indeed, even producing the illusion that a self is in control of its thoughts and actions. This is typical of neuro-research, and such research findings/opinions so disturbed Tom Wolfe that he wrote his well-known "Sorry, But Your Soul Just Died." (See sidebar.)

Gazzaniga is a founder of cognitive neuroscience and has studied brain architecture in terms of the nature of the self. In his book he musters battalions of arguments to show it as an illusory construct. Near the opening he has this to say:

"We think our personal selves are directing the show most of the time. I argue that recent research shows this is not true but simply appears to be true because of a special device in our left brain called the interpreter. This one device creates the illusion that we are in charge of our actions, and it does so by interpreting our past--the prior actions of our nervous system."

An example of illusory control can be found in some epileptics who have had the corpus callosum severed to eliminate their seizures. It connects the right and left brain hemispheres and without it the two do not "talk" to one another. A split-brain patient is shown an image in his left visual field (the left half of what both eyes take in) and cannot name what he has seen. Why? Because speech-control is on the brain's left side and left-field images are sent only to the opposite, right, side of the brain.

Take a split-brain patient and flash a picture to only one side of his visual field. Suppose they flash a picture of a chicken to the right brain only. The patient cannot say what he is seeing because the left hemisphere, the interpreter, controls language, and the right side is severed from it. If asked to point to the chicken picture the patient can do it because the interpreter is not involved.

The interpreter plays tricks to maintain the illusion of control. When the patient's right brain is shown a command like WALK, he begins to walk to the door. When asked why he is leaving, his interpreter has an answer for the researcher: To get a drink of water.

The first chapter of The Mind's Past is titled "The Fictional Self," and addresses the existence of the interpreter in the left hemisphere. The author explains it as a narrator that reconstructs our past and weaves it into a life story. As narrator, it promotes the belief (for Gazzaniga, read "illusion") that we are in control of our story. When reading about it, the term "spin doctor" came to my mind. Yet, most of our neurons fire below the level of consciousness, and as automatic systems work outside our awareness. I do not have to make a deliberate decision on each of these keys as I type.

Titled "Brain Construction," the second chapter would provide a revelation for 18th Century philosophers such as John Locke, who said the mind is a blank slate, or tabula rasa, to be written on by environment. Revelation, in that we have learned so much about the brain that was unknown in Locke's day. For moderns, though, it would provoke argument. Gazzaniga urges that today too much importance has been assigned to environment and neuroplasticity. In his work with obsessive-compulsive patients and neuroplasticity Jeffrey Schwartz would be among those who differed with him. (See Schwartz, Neuroplasticity and The Power of Mental Force.) Divided on simplistic lines, we have here the nature/nurture debate, in which Gazzaniga comes down on the side of nature. He sees in brain modularity and genetically-driven mechanisms a powerful argument for nature.

The third chapter, "The Brain Knows Before You Do," argues against the belief that we are in control. In short, our brain and its mechanisms control cognition as well as behavior, and leave the false impression that they have been controlled, and are not the controllers they are. An illustration in the book shows a brain dragging somebody into the future, while he lags behind in an illusory "now." (In his experiments Benjamin Libet provided evidence that decision to respond happens after the actual response by roughly 500 milliseconds.) Gazzaniga boldly opens the chapter with this declaration: "By the time we think we know something--it is part of our conscious experience--the brain has already done its work. It is old news to the brain, but fresh to us." This puts an end to the self and its belief in control, he in effect says.

Elsewhere in the book he explains that most memories serve the narrative self in that events are reconstructed to support belief in the continuity of self, and personality. Popular lore has memory as a trove of organized recollections and when one part of the brain is stimulated by a modern Wilder Penfield a certain memory sparks up, and with a different part, a different memory. Not so, according to the author. Instead they just help the brain's interpreter.

Gazzaniga probably believes that we will eventually discover the neural correlates of consciousness, and well we may. That still leaves me with David Chalmers' "the hard problem of consciousness": What is it like to be me? What is it like to be you? Consider a totally color-blind person perceiving black/white/grey who has scientifically studied color (wave-lengths, etc.) all her life. At the end of her studies will she be able to appreciate the beauty of flowers in a garden? Such problems have turned Chalmers into a kind of dualist (the universe cannot be reduced to just one thing). Others--Daniel Dennett, for example-- dismiss Chalmers and his hard problem as simply a non-problem. Gazzaniga's faith in the scientific method is heard when he states that the "old" psychology is dead because "the grand questions [of] classical psychology have evolved into matters other scientists can address." In a gracious sweep, he includes various psychologists and their fields.

Eastern religions are anchored in not-knowing, a glue for morality and social fabric. Of that from which all emerges, the Bhagavad-Gita says it "cannot be pierced or burned, made wet or dry," thus indicating these are only words pointing to something beyond concepts. (Nisargadattta: "Fight with all the strength at your disposal against the idea that you are nameable and describable.") That is not the case with science. It is about establishing concepts, about knowing and wanting to know. In reading this book, Tom Wolfe's phrase returned to me again and again. "Sorry, but your soul just died." Wolfe had more than an apology in mind. He sees the far-reaching consequences of the remark. Thomas Metzinger (The Ego Tunnel) expresses concern for ethics and societal health should the idea become widespread that "mind" and "self" are fictions. Still, science must know while scientists ask Why?, and rightly so. Despite that, I remain ambivalent toward our future. In step with the physicists who developed the atomic bomb--and I say this with irony although I am not a Luddite--science marches on.Bookmark and Share