Customer Reviews

The Mind's Past

5 star:		(4)
4 star:		(7)
3 star:		(5)
2 star:		(2)
1 star:		(0)

 

 

This book takes a look at long held assumptions about human consciousness, and examines them in the light of modern empirical neuroscience. It examines the processes of perception and the work of the left brain's "interpreter." It's an uncommon look at "common sense."

The first chapter of the book examines the "Fictional Self," and continues to weave this thread of thought throughout the book. What fascinated me most about this line of thought was that it paralleled ancient Eastern thought about the illusion of individual reality. However, Dr. Gazzaniga's book does not draw on these ancient traditions, and it is up to the reader to figure them out.

Dr. Gazzaniga writes, "... the primate brain prepares cells for decisive action long before we are even thinking about making a decision! These automatic processes sometimes get tricked and create illusions - blatant demonstrations of these automatic devices that operate so efficiently that no one can do anything to stop them. They run their course and we see them in action; as a consequence we have to conclude that they are a big part of us." p. 20

In The Bhagavad-Gita it says, " As the ignorant act with attachment to actions, Arjuna, so wise men should act with detachment to preserve the world." (3rd Teaching, 25, translated by Barbara Stoler Miller) Just like "The Mind's Past," The Bhagavad-Gita points out the illusion of willful action. Dr. Gazzaniga's empirical observations have a poetic parallel in The Bhagavad-Gita.

The book also examines the dual functions of perception, the flow of perceptual information to the parietal and temporal lobes simultaneously, one prepares the body to act within reality, and the other constructs an illusionary perception of reality. This was also noted by physicist Richard Feynman in his lecture on space/time, commenting on our inability to perceive space/time as it really is; which is also a fundamental concept found in Hinduism, Buddhism and Taoism.

On page 157, Dr. Gazzaniga reports on an experiment in which humans, using the left brain "interpreter," chose the right response 68% of the time, while none-interpreting animals get it right 80% of the time. "While it quickly becomes evident that the top button is being illuminated more often, subjects keep trying to figure out the whole sequence and deeply believe they can. Yet by adopting this strategy, they are rewarded only about 68 percent of the time. If they always press the top button, they are rewarded 80 percent of the time. Rats and other animals are more likely to learn to maximize and press only the top button. It turns out that our right hemisphere behaves like a rat's. It does not try to interpret its experience and find deeper meaning. It continues to live only in the thin moment of the present." This right brain strategy is Taoism at its essence.

This book is an interesting read, and highly recommended to anyone who is a student of perception. It will challenge the egocentric view of reality, and will provide an unwelcome jolt to a belief-system of egocentric reality, but it does so with humor and scientific insight.

This lightly told, but hardly frivolous, study of the mind/brain refutes many long-held notions of what comprises the conscious mind. Gazzinga's approach is an attempt to inform us all of the real status of "self." He contends the "self" - hence, "free will" is a conceit. We pretend to have consciousness through our desire to establish identity, but the brain has its own, hidden, mechanisms of which we are only now becoming aware. He stresses the evolutionary roots of our minds, roots which may not compel behaviour, but certainly drive it with forces we fail to perceive readily. It's an amazingly complete work in spite of its brevity, rewarding to anyone opening its pages.

Gazzaniga is a clinical researcher, not a field worker. This doesn't impede his stressing an evolutionary development for how our minds work. Gazzaniga posits an "interpreter" as residing within our left brains. The distinctive roles of the left and right halves of the brain have been the subject of intensive research during the past years, but his assessment has some novelty. It is rather more than the classical "Cartesian Theatre" which has held sway in the minds of many psychologists and philosophers over the years. Gazzaniga's "interpreter" outperforms the role of "observer" postulated by Descartes. It has moved from Descartes' pineal gland to the left cortex. In Gazzaniga's view, the "interpreter" has a more active role, even powered to stimulate activity in sensory areas, previously thought to be wholly reactive. This device is rooted in our animal ancestors, living in a dangerous environment, needing to predict events for survival and reproduction. We have progressed beyond those roots, but the function has had long career, according to Gazzaniga. He stresses that we must learn more about its abilities and operations.

His use of sources is awkward. While utilizing the work of numerous researchers in his account, his attributions are hazy. The appended notes are collected by chapters, but relating the list to the text is difficult. Countless workers noted in the text fail to appear in the notes. We have only Gazzaniga's assurances that his references are valid. While his approach makes for easy readability, one's own "interpreter" sits uncomfortable at these omissions. Many well-known figures in consciousness studies are omitted. He builds a superb case, but it seems to rest on a shaky foundation. Still, his assertions need response and it will be fascinating to see who answers his contentions.

The first half of this book is a very good story about how mammalian brains function. Mercifully, it's not a drawn out document on neuroanatomy and neurophysiology, but rather a description how the emergent forms of neuroanatomy and neurophysiology function; about how the brain works. In this respect it's a fascinating and informative essay written for the lay reader by a very eminent neurologist. Gazzaniga's ease of translating the dessicated lexicon of neurology into a cozy fireside tale is certainly a testement to his literary skill over and above his medical acumen.

The second half of the book trails off into monotonous case studies and lacks the zing of the opening chapters. I rated this book a five however because it carries such a seminal point that in itself is of astounding significance. The human brain is no where near as plastic as it's given credit for being in the popular literature. We all know what a brain looks like. Just thinking of the word brings to mind a fixed image we've all seen in myriads of represnetations. They all sort of look the same, and guess what, they all sort of function the same way too: function follows form, or, as Sartre said, the essence is revealed in the appearance, not concealed by it. This is not to say that the brain functions how it looks, but an analogy illustrating that a brain's function is based on its form, or, its anatomy and physiology. You'd think this would be obvious but apparently for some reason it isn't. It's is an important point and Gazzaniga breaks it down very plainly and simply. The idea that neural function follows form is not immediately apparent to the lay person because it is a very politically unpopular view. Not a neurologically unpopular view but a politically unpopular view. Think about it. Contemporary social policy strongly prefers a view that the brain is molded by environment so it can sell policies to solve problems. The brain, long evolved over eons has its own agenda however. Any pediatric neurologist can tell you, tragically, how the brain tolerates very little variation in local structure and chemistry; kids born with slight variations in brain anatomy and chemistry are subject to acute difficulties. We're all really very much more similar in terms of how our brains function than we generally allow for. The brain is, to be blunt, a product of genetics, "those pesky little robots of nature" as Gazzaniga calls them. Obviously, as E. O. Wilson learned, the world is not yet ready for sociobiology. Gazzaniga ignores such political correctness and proceeds to discuss how the brain actually functions, not how some may wish it to. Gazzaniga would have us consider behavior based on neural function as an endocrinologist would consider diabetes relative to pancreatic function; by material cause and effect. Can you imagine the chaos such a view would cause in a cultural system based on the idea of free will from the Protestant aesthetic of John Winthrop? More, it seems, of people's behavior is based on their brain structure and chemistry than on environmental factors, an idea clearly counter to popular beliefs.

Gazzaniga also takes great pleasure in pointing out that we unconsciously lie a lot and concoct in voluminous quantities. This is how our brains are evolved to function, that is, to lie and create fantastic realities; and to great adaptive success one might add. This idea is not necessarily new for sophisticated idealists, although it is still not palatable to uprightly moral types because they tell the truth (really they do). We make the world we observe to a very large extent in our materially imaginative minds and Gazzaniga elucidates such a fantastic notion in a straight forward discussion that raises as many questions as it answers.

All in all a short, sweet, easy read on how brains function by a highly qualified observer.

Gazzaniga argues succesfully that the brain, and therefore the mind, is a product of evolution and to an extent genetic determinism. His descriptions of the developing brain are compelling. The book is overall a review, from Gazzanigas point of view, of cognitive neurosciences. Few other people could be better qualified. Gazzaniga is the editor of the New Cognitive Neurosciences, arguably the best and most complete collection on the subject. Insight after insight follow from his quick and witty prose. This is an informative and easy book, that anyone interested in neuroscience should enjoy. Maybe some things could have been given much more space, but Gazzaniga sticks with what he knows best, like, for example, split-brain patients.

If I would have a complaint it would be on his poor treatment of consciousness. The study of consciousness is probably the most promising and difficult, and some would say the only true mystery left in the neurosciences. Gazzaniga presents a left-hemisphere interpreter theory, but as far as I can see, that is a theory of reportability and organization of conscious experience, not consciousness itself. It seems that what compells Gazzaniga in this point is the fact that language is, generally, a left hemispher function, and a presuposition that language is essential for consciousness. This is far from being established, and in fact, I believe evidence points to the possiblity of consciousness without language. Consider a monkey that has working memory, adequate behavior, self recognition in a mirror, and who some use to study binocular rivalry. Even much more critically, consider an aphasic or a deaf-mute.

This little book (200 pages) attempts to take the reader on a tour through the latest developments in cognitive neuroscience. Ultimately, The Mind's Past highlights the importance of narrative in constructing the conceptual self. It's fair to say that the book succeeds in rousing interest in the subject, though it's also fair to say that Gazzaniga is not a gifted science popularizer. At times it is hard to know whom the book is written for - layperson or expert. There are some instances where Gazzaniga makes no concession to a popular audience, and other times when he seems to oversimplify. At no time are we in doubt as to his opinions of his fellow scientists, however, as he goes out of his way to praise or criticize.

Gazzaniga also makes no effort to disguise his disdain for psychology as a scientific endeavor. "The grand questions originally asked by those trained in classical psychology have evolved into matters other scientists can address ...Psychology itself is dead." What Gazzaniga means by this stance is that classical psychology actually leads nowhere because "the answers don't point to a body of knowledge where one result leads to another." On the other hand, cognitive neuroscience focuses on the biological mechanisms which cause the brain to enable the mind to perceive reality and construct the "fictional self."

Gazzaniga is at his most interesting when he explores the notion of the "interpreter", a mechanism in our left brain which "creates the illusion that we are in charge of our actions and does so by interpreting our past." Through a cursory explanation of key experiments in cognitive science, Gazzaniga shows how the left brain is involved in the persistence of personal narrative. The interpreter's job is to conflate events and weave a meaningful story around those events. This is fascinating stuff. It seems that the need to construct narrative is deeply rooted in the brain. But why, and to what purpose?

As an evolutionist, Gazzaniga repeatedly asks the question "What's it for?" in his approach to explanations. Ultimately the brain's purpose is to increase chances of reproductive success. Everything else is frosting on the cake. The purpose of the constructed self, and the purpose of memory, says Gazzaniga, is ultimately to localize things in space. Memory helps us remember where we stored food, where base camp is, and where we saw the desirable mate. Memory is notoriously self-serving, however, and quite false by nature. "As we spin our tale, calling on the large items for the schema of our past memory, we simply drag into the account likely details that could have been part of the experience." Memory is by nature unreliable. While the right brain "regurgitates" the literal story, the interpreter (located in the left brain) "remembers the gist of the story line and fills in the details by using logic, not real memories." The findings bear heavily on false memory syndrome, especially in children, where experiments have shown that 58 % of children claimed that at least one of the false events presented to them in an experiment happened to them, and 25% produced false narratives for the majority of them!

The substantive difference between our species and animals is our ability to reason. All sorts of animals can engage in associative learning, which allows them to make connections, say, between eating something and getting sick, in order to avoid doing it again. What humans do is to take it one step further, asking "Why did that plant make me sick?" "Sustained syllogistic reasoning, the capacity to state a major premise, then a minor premise, followed by a deductive conclusion, is what our species alone can do." This ability to reason has huge payoffs for our species in helping us to make predictions about the future. Where it fails us is in attempting to interpret large sets of meaningless data, superimposing a spurious narrative which gives comfort to our false sense of self, making us feel in control when we aren't.

Gazzaniga does not venture into metaphysical territory, but the import of recent findings in cognitive neuroscience certainly lend themselves to all kinds of speculations. If, as Gazzaniga says, our right brain is a mechanism which lives entirely in the present, refusing to interpret its experience to find deeper meaning, and the left brain always comes up with a theory for things, even at the expense of superimposing a false theory to replace randomness, what does this mean about meditative states? When we meditate, are we somehow suppressing the left brain, allowing our conceptual self to dissolve in order to experience the immediacy and primacy of experience which the left brain normally denies us? Someday we might know. Our interpreter asks "how infinite numbers of things relate to each other and gleans productive answers to that question," leading inevitably to the question "Who is solving these problems?". The simple and not quite accurate answer to that question is "I am." The conceptual self which the interpreter creates reinforces our notion of centrality, thereby providing a glue that holds our story together. The accuracy of our story is not the point; the imposition of a narrative notion of self is. Ultimately these narratives of our past pervade our awareness. To be aware of the limitations of our brains and the way brain and mind relate is to be empowered to transcend those limitations.

PHYSICAL: Neat little book (measures 7.25" by 5.25"). STYLE:It suggests an edited compendium of lecture notes, written in a style both colloquial and academic. STRUCTURE: Lots of neat experimental results summarized in (usually) clear manner... these are the 'pumpkins'. Following the 'vines' connecting the 'pumpkins' can be both interesting and confusing, as the overall structure is somewhat convoluted. Oh, and there are a lot of 'leaves' hiding the pumpkins. This book was NOT written using an outliner program! CONTENTS: Lots of good stuff: how the brain makes decisions before consciousness rubber-stamps the unconscious choices with its "yup!"; how Kant's later writings may have been strongly influenced by a left prefrontal lobe tumor; language development being a direct outgrowth of specific brain tissue development; why the brain notices movement in the lower half of the field of vision more so than in the upper (why guerrillas might well be advised to hide in trees); oodles of information about brain structure (no maps included, so get out your Gray's); etc, etc. APPENDICES: Good Bibliography (arranged by Chapter) and good Index. Sample mentions from Ch 1 bibliography : Noam Chomsky, Richard Dawkins, Jane Goodall, Stephen J. Gould, Stephen Pinker, E.O. Wilson... pretty wide ranging. The experimenters whose studies fill page after page are mostly unknown to me, but their results provide fascinating insights. ... Could this book have been better? Sure, but it's not a bad read anyway -- a good place to start following one of those 'pumpkin vines' into new patches of knowledge....

This book is, of course, an attempt to provide for the layman a comprehensive, comprehensible summary of the current state of cognitive neuroscience, not an easy task. Gazzaniga has the credentials to do this, being Director of Cognitive Neuroscience at Dartmouth and the author of several authoritative texts on the subject.

The suprise is that he has the capacity to make this palatable for the lay reader. I found his discription of the methodology and the current findings absolutely astounding. To read the clever experiments that pry open the functions of the brain is awe inspiring. The reader can only marvel at the complexity of human mental function, but with an inkling that we have the power to unravel its mysteries.

This book clearly demonstrates the progress that we are making in this area. Moreover the study of abnormal brain function is eye-opening in its implications for our understanding of normal brain activity.

Well worth reading!

In the 1960's, Michael Gazzaniga and Roger Sperry (the Nobel laureate) undertook a series of pioneering and innovative studies of human split-brain patients. These were people in whom the corpus callosum, a bundle of nerve fibers which links the left and right cerebral hemispheres, had to be excised for medical reasons. Gazzaniga and Sperry went on to make many startling discoveries about these patients. One of the key discoveries from these and subsequent studies was that one of the functions of the left hemisphere is to continually provide an interpretive framework for our experiences. Much of "The Mind's Past" concerns the issue of how this left brain device (Gazzaniga dubs it "the interpreter") provides us with a convenient fiction: that we are autonomous agents, independent selves, with free will, fully in control and capable of determining our own actions. Gazzaniga sets out to show the reader how that interpreter is superimposed over the operations of a multitude of other brain devices, which perform their work `behind the scenes' so to speak; thus, "the brain knows before `you' do".

Gazzaniga's central thesis is this: the brain comes filled with a variety of built-in gadgets (what Steven Pinker would call `organs of computation'). These specialized modules are products of natural selection (the only purely physical process capable of generating complex design) and they handle the kinds of problems that must be solved in order to get around in the world, to survive and ultimately to procreate. Fortunately for us, this staggering multitude of processes goes on outside of our awareness - the gadgets work on automatic pilot. Approximately 98% of the brain's operations are not consciously accessible, though we can certainly be aware when some of these devices malfunction as when, for example, we lose the ability to detect motion in the world around us. The brain's computational organs just churn away, working on the basis of given assumptions (some of these assumptions can be made explicit with clever visual illusions) and they take care of the main tasks of life. They have done this for thousands of years.

The interpreter, then, is a device that sits atop of the information processing hierarchy; on top of a hierarchy of sub-symbolic information processing stages. It can make us aware of some of the output of those automatic functions - sometimes making gross errors in the process. Gazzaniga's discussion of the interpreter and his examples of the extents to which this narrative-constructing device is ready to impose order on events is the most interesting part of the book. His own research with split-brain patients informs a great deal of this discussion.

Gazzaniga cites a plethora of research findings to bolster his case, including some of the big findings that have emerged from the fields of evolutionary psychology, cognitive neuroscience and developmental neurobiology. He also takes issue with the more extreme versions of connectionism which view the brain as a general purpose problem solver. According to that view it is the environment, via massive backward propagation, which calibrates appropriate outputs to relevant inputs (i.e., the organism learns appropriate ways of responding to categories of environmental events). In contrast to this 'tabula rasa' theory, Gazzaniga sides with the main tenet of evolutionary psychology: the structure of the problem space comes embedded in brains in a variety of modules -- complexity is a given not a construction.

Unfortunately, the book has several drawbacks. For one, the writing is a bit dry in some places and this makes reading the book, despite its brevity, a laborious process at times. Also, the research which is covered often involves complex experimental designs which resist being summarized in a few paragraphs - and while the intention was to present the basic implications, some times these are difficult to really grasp without the relevant context and background. Another problem is that the book vacillates between seeming to assume at least some familiarity with the field at one point, but then over-simplifying the issues at another end. All in all, a somewhat inconsistent effort, that does not cover much in terms of new material.

Gazzaniga's concept of the "interpreter" has made a major contribution to my understanding of what goes on in my brain, for which I'm grateful. The research he describes in support of the idea is very convincing, but there are some serious problems with his conception of mind/brain duality.

On page 151, he gives a brief summary of the interpreter's job: "In general the interpreter seeks to understand the world."

Located in the left hemisphere--at least in the subjects who've been tested--the interpreter is intertwined with the use of language. Language is required for the kind of understanding that involves the construction of rational arguments, an activity that brains without language are incapable of. Non-linguistic brains can learn by associating a stimulus with a response, but it takes language to ask "why" the stimulus provoked the response.(p. 152)

This kind of understanding-through-language places some rather profound limitations on the abilities of the interpreter which Gazzaniga fails to explore in depth, with the result that confusion reigns where clarity otherwise might. Like many other writers on brain function, he is stuck with a conception of "mind" that results in a plethora of paradoxical statements.

The confusion begins on page 1: "After the brain computes an event, the illusory `we' (that is, the mind) becomes aware of it..." (His parenthesis.) This is as close as he comes to defining "mind," although we can get some further ideas of what he means from contexts in which he uses it. For example, a few pages later he writes:

"Our mind has an absurdly hard time when it tries to control our automatic brain. Remember the night you woke up at 3 A.M., full of worry about this and that? Such concerns always look black in the middle of the night. Remember how you tried to put them aside and get back to sleep? Remember how bad you were at it?"(p. 22)

And on the next page:

"Nowhere is the issue of ourselves and our brain more apparent than when we see how ineffectual the mind is at trying to control the brain. In those terms, the conscious self is like a harried playground monitor, a hapless entity charged with the responsibility of keeping track of multitudinous brain impulses running in all directions at once. And yet the mind is the brain, too. What's going on?"(p. 23)

He never answers that last question, although he discusses a lot of information that might allow him to. The answer is that the mind (our conscious experience, including the interpreter and its language as well as sensory experience), is the product of brain processes, and it doesn't control anything, much less the "automatic brain" that creates it.

Our conscious experience is the measure of the brain's abilities and of what it knows about its own processes, and if we read Gazzaniga's book for explanations of the gaps in the brain's understanding of itself and the rest of the world, and why it has them, there is much to be learned. He can teach us things that he doesn't seem to know himself.

The brain has many abilities that it doesn't understand, and Gazzaniga points out quite a few: the brain can walk, talk, produce a useful visual model of the world, etc., without having a clue about how it does any of these things: "As I sit and write, I am not aware of how the neural messages arise from various parts of my brain and are programmed into something resembling a rational argument. It all just happens." (p. 22) If Gazzaniga doesn't know, his brain doesn't know, either. It can construct a rational argument without knowing how it does it.

Another limitation on the brain's verbal explanations is that it doesn't have a wiring diagram of itself, and if parts of it get damaged, it often is not aware of the abilities it has lost unless it tries to do something it remembers being able to do and finds that it cannot. The brain can't attach language to information it doesn't have; it can't explain anything unless it has some awareness of it. Here's one of several descriptions of this kind of phenomenon: "...the patient with the central lesion doesn't have a complaint because the part of the brain that might complain has been injured."(p. 135)

To see how eliminating the mind/brain duality can add some clarity to Gazzaniga's discussions, let's go back to his example of 3 A.M., struggling with our thoughts, trying to get back to sleep. It's not that the mind is struggling with the automatic brain, as he puts it, to quiet these thoughts that are keeping one awake. It's that there's a neural network (or circuit, or brain state) that is concerned with sleep and rest that is alternating with another neural network that evaluates the problems one's thinking about as more important than sleep. What we experience in consciousness is, at one moment, the neural network that is in favor of sleep comes to the fore and says, "I've got to stop thinking about this stuff," and the next moment, the neural network that evaluates the priorities of these disturbing thoughts is bringing them to the fore; it's winning the competition on what is important at that moment. This competition is the result of all the things that the brain is aware of at the time, prompted by the environment: the bills that have to be paid with not enough money, etc. and the part of the brain that deals with those issues is in the ascendency. It's getting reinforcement from other parts of the brain. It's like a committee meeting in that there are different factions and some say, "Oh, this is the thing that we have to deal with," while another faction says, "Oh no, this is the thing we have to deal with." We aren't aware of all the behind-the-scenes negotiations; we are only aware of what emerges in the foreground: this vacillation between the need for sleep and the need to deal with these issues. (In this video from late 2008, Gazzaniga describes a process very much like this in talking about consciousness:[...])

If you apply a similar construction to all Gazzaniga's uses of "mind," you will have a much clearer idea of the human condition and his contribution to its understanding. I'll give one more example from his final conclusions: "The interpretation of things past... produces the wonderful sensation that our self is in charge of our destiny... Because of that, maybe we can drive our automatic brains to greater accomplishments and enjoyment of life."(p. 175)

Rephrased: If the brain realizes that the "sensation that our self is in charge of our destiny" is an illusion, it may turn its attention to the likely determinants of its self-concepts, its accomplishments and its enjoyment of life; the understanding of which will open up vast new opportunities for the brain to consider.

In this accessible and interesting book, Gazzaniga offers persuasive evidence to support his premise that the brain makes choices and begins to act before we are consciously aware of the fact. He suggests that an "interpreter" in the brain's left hemisphere constructs a coherent narrative of consciousness after the fact, which provides us with an illusion of free will. However, the evidence for the existence of this interpreter is strictly (if powerfully) circumstantial, and Gazzaniga never offers details as to where specifically he thinks the interpreter is located, how it would have evolved, and how specifically it functions. I also felt that his condescending attitude toward those who disagree with him kept him from seeing their evidence, and interfered with the effectiveness of his own argument.