The Executive Brain: Frontal Lobes and the Civilized Mind [Paperback]

I just have one other comment about this, although not the specific focus of the book, but much of this information has relevance to the classical philosophical issue of the mind-body problem, and I thought I would make a few comments on that.

Although we may not understand consciousness at the neuronal level very well yet, this doesn't mean that someday consciousness won't be completely reduced to a neuronal explanation. Even if complete reductionism is unattainable, it still seems an unavoidable conclusion that consciousness must depend on the brain as a result of studies based on many areas, of which I will only mention one here: those related to the study of brain damage, many examples of which get discussed in this book.

For example, it is easy to demonstrate that as a result of certain degenerative brain diseases and syndromes, neurons in different parts of the brain begin to deteriorate and die off. Eventually, the person becomes extremely impaired intellectually, and ultimately, consciousness itself fades away into nothing.

This progressive deterioration of the mind and consciousness as the brain cells die off, with the degree of impairment being proportional to the degree of brain damage, provides powerful evidence that the brain is behind these phenomena, despite our current inability to arrive at a complete explanation. In fact, it seems impossible to reconcile them in any other way.

If the physiology and anatomy of the brain are not behind the mind and consciousness, then how are the above facts to be explained?"

On the contrary, since without the brain the sense organs cannot function, the body cannot perform its work, and the mind in all of its many aspects, including consciousness, completely disappears, the brain itself has to be the basis for it.

Furthermore, although we can't explain fully how consciousness arises from neuronal mechanisms, this doesn't mean we don't know where it is in the brain. In fact, we can localize it to a particular area. This is the cerebral cortex itself. In Greek, cortex means "bark," or thin layer, and that is exactly what it is. The human cerebral cortex is only a few millimeters thick, but without it, there is no consciousness, no lower or higher mental or cognitive functions, no language capability, and no personality as we know it. Remove this thin sheet of neurons, and what remains in a human being is only very primitive vegetative and physiological functions such as thirst, hunger, fear, and basic motor functions. However, even motor control in a human is irreparably damaged, resulting in a condition known as "decerebrate rigidity," where the skeletal muscles become excessively rigid and inflexible.

Recent research shows that consciousness is the result of processes and mechanisms occurring in diverse and separate parts of the cortex which have to be coordinated in time for consciousness to occur. In other words, there is no one area in the cortex or the brain in which consciousness resides, and it is actually composed of many different components, in contrast to classical philosophical models which saw consciousness as a simple, monolithic, indivisable construct or phenomenon.

Anyway, just a few thoughts on the subject of mind-brain dualism, and why the traditional dichotomy in philosophy is so wrong-headed and false.