Friday, July 13, 2007

Mind and Brain (Repost from AMNAP 1.0)

One of the assumptions of most people with a "scientific" worldview is that human consciousness is entirely a function of the brain. One reason for this is the well-known finding of neuroscience, that damage to the brain often affects the functioning of the mind. For example, damage to or destruction of the hippocampus through stroke or brain injury will lead to memory impairment of varying degrees. Probing different parts of the brain with electrical currents can lead to reliving memories or experiencing emotions. And a loss of blood flow to the brain leads to immediate unconsciousness.

However these phenomena can be interpreted in multiple ways. The standard reductionist viewpoint of the brain could be termed the "ipod model". That is, the hardware, software and content are all encoded and packaged into a stand-alone device. The obvious alternative to this is the "radio" model. A radio looks very much like a tape player or an ipod. Removing components from the radio may prevent it from playing certain bands (AM or FM), lock the tuning onto a particular station, or create distortion in the music. However the music itself is external to the device, and destroying the radio does not destroy the music.

Which of these two models is correct? Is mind / awareness / memory solely a product of the brain, or does the brain "tune into" and affect the mind in some fashion? There are a number of relevant points of fact that shed some light on this question.

The first pertinant factor is the current state of understanding of the mind from the findings of neuroscience. Have the mysteries been solved? Despite the absolute certainty of reductionists that the mind is fully explainable in terms of neural properties, the most prominent questions today are the same questions we had fifty years ago. Certainly, neuroscientists have faith that most or all of these questions will be answered soon with materialist explanations, but this is more a matter of faith in their assumptions than anything else.

Despite many decades of investigation, the sacrifice of thousands of laboratory animals and the efforts of the best minds in neuroscience, memory traces have never been located in the brain. In exasperation, some have posited a "holographic" or distributed storage of memories throughout most or all of the cortex, while others embraced a non-material aspect to the mind and memories.

Brain functions are highly plastic, after a stroke, some patients are able to recover from massive loss of abilities through remapping areas of the brain to take on new functions. What, exactly, is organizing this recovery?

Some people have demonstrated a high degree of functioning despite the lack of most or nearly all of their brain tissue.

Psi experiments provide substantial evidence that mind phenomena extend beyond an individual brain in space-time.

Near-death experiences with veridical perception have been reported when the brain is completely shut down.

Genuine mediums have brought back information from the deceased, even under tightly-controlled experimental conditions that preclude ordinary explanations.

All of these factors give support to the "radio" model of the brain and consciousness versus the "ipod" model.

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