jueves, 17 de diciembre de 2009

Expanding the Human Mind: The Future of the Brain: Neurobiology, Electronics, and Other Tools Part 2

Why Pursue Brain/Mind Enhancement?
Why might we wish to move in this direction? One reason is simply to restore damaged brains. Physical injuries, strokes, tumors, and neuro-degenerative diseases in the brain cause heartbreaking disabilities. The afflicted individual may live a much reduced life for many years. What a tragedy to lie paralyzed, or to live among family and friends without comprehending their words.

Another motivation is personal development. We are not born equal. Our society is gradually acknowledging that many are born with strong propensities for mental illness such as depression or addiction, difficult or impossible to combat by pure mental effort--i.e., by a "strong will." Thus medicinal remedies are now accepted, which in reality are molecular probes that attach to selected neurons in the brain. Besides problems of outright disease, some of us are much smarter, happier, more confidant, fearless, and likeable than others. If we understand the basis for such differences, why should less-favored individuals not overcome their weaknesses, rather than struggle for a lifetime with their suboptimal neural constitution?

It is important to realize that most long-term mental changes will take considerable time to achieve, both to change the quantity and quality of the neurons involved and to create the more subtle modifications that will come with use. For example, instilling the qualities of pitch discernment, timing, and finger agility of skilled musicians would undoubtedly require the modification and growth of many auditory and motor circuits, plus much practice to develop their potential.
In general, the scope for quick, effortless change by taking a pill will be quite limited. This is fortunate, since human relationships, both personal and societal, depend on predictability. Rapid changes in personality, motivations, habits, and skills could produce social chaos.

Building Better Brains
Looking further ahead, can human beings add useful new capabilities to their minds? For example, a method of directly sensing by touch or sight the entire three-dimensional constitution of an object would be a giant mental leap, bringing to our mind the ability to directly observe the patterns of forces, motions, heat, and fluid flowing in our environment. You could be simultaneously aware of the actions and activities of all parts of your body, inside and out. Three-dimensional sensing would bring solutions at a glance to many practical problems that now require extensive training and computer aids to solve.
A personal digital assistant placed on or within your body could make comparable three-dimensional calculations, but the assistant would always be an outsider, integrating with your brain only as a little voice whispering in your ear or a screen holding up pictures to view. Integrating at a deeper level than the senses will require complex connections--and vastly more of them--as well as coping with the far greater speed of electronic pulses compared with neural pulses. Still, as we will see below, the digital assistant and the brain may eventually get together.

Our conscious mental sensations define us as humans and individuals. They are clearly associated with structures in the brain, which leads us to wonder if new neural structures supporting new mental powers will lead to new mental sensations.
It is certainly not clear what neural structures might support the three-dimensional sense I have just described. But we do have two existing senses to guide us. First, our bifocal vision is a partial sense of a three-dimensional surface. Second, our senses of touch, physical position, and motion combine to provide us with a crude three-dimensional sense of our body in space. When we learn how the neural structures supporting these senses function, they may guide us in designing and integrating into the brain comprehensive three-dimensional senses.

There are further possibilities--novel emotions, novel modes of sensing. Such explorations will take much effort, their purpose not pursuit of novelty for its own sake, but rather an attempt to explore the possibilities, to discover if there is a systematic world of mental sensations as real and extensive as the material world we perceive with our present senses.

Longer-Term Futures: Mind and Mental Function
In time, we will accumulate detailed functional descriptions of the brains of large numbers of individuals. Many will contribute all or part of their personal information to a common pool, sharing with the world how their individual differences in brain structure and function contribute to differences in mental characteristics, from personality to talents. The information will point in two directions. Just as today we acknowledge that some of us are especially susceptible to mental illness, tomorrow's vastly deeper knowledge of the functional differences in brains will foster greater understanding and acceptance of people as they are, how their lives are constrained by the physical constitution of their brains.

However, we will no longer be resigned to living with what we began life with. We can move to change our mental makeup by modifying our brain's functional structure, to enhance what we like and diminish what we don't, proceeding on the assumption that all normal human brains, free of major mutations or accidents of development, have the same complement of neural structures, just as we all have the same set of muscles, bones, and ligaments. Our physical individuality comes from the differences in their size, length, and shape.

At its simplest, functional differences in the same neural group will depend on the number of neurons in the group. We can place modified neurons within the group to send inhibitory signals that effectively decrease the number of neurons. To effectively increase their number, we can send stimulating signals that lower their firing threshold, thus making fewer neurons do more work. Over the long term, stimulation may also increase the number of neuron branches, further enhancing the neuron's effectiveness.

There is surely some limit to enhancing the existing neuron supply. When we need more neurons, we can place modified neurons within the group and induce them to form connections.

A far more formidable challenge will be to connect neuron groups to distant parts of the brain and body. One approach is to place a line of "beacon" cells to guide the growth of new branches along the desired path. Another, more radical way is to connect the neurons to an electronic interface, which would convert the neuron's signals to electronic signals and relay them directly to the target neuron group.

The electronic interface can be upgraded to make arbitrary connections by adding digital switching circuits. Additional circuits could turn the interface into a computational facility to aid memory or make instant simulations. The interface would become the digital assistant described earlier, with the potential to connect naturally to any portion of the brain rather than only to the sensory inputs. Of course, we would need a deep knowledge of brain function to make useful connections rather than creating chaos.

A New Brain, and What We Might Do with It
If we can systematically add (and subtract) neurons from functional groups, where can it all end? Can we effectively transmute one brain into another?

There are several qualifiers. First, we are dealing with actual growth, which takes time. Second, genes will vary between individuals, creating variations in each of the neuron types. While we can try to compensate for genetic variability by using modified neurons to administer neurotransmitters, inhibitors, enhancers, growth factors, etc., we would really need to modify each neuron's genetic complement to transmute its function completely. And third, brains have a lifetime of experience, which will impose biochemical adaptations on each neuron, reflected in its pattern of branching and its patterns of stimulation and response. Experience will still count. Nevertheless, biological inequality will no longer seem inevitable.

What about capabilities we have yet to conceive? Can we add a genuinely new capability to the human mind, complete with never-experienced mental sensations in our consciousness? For example, the light-detecting cells in the eye sense only three colors--red, green, and blue. Their signals are sent to the brain and combined to produce the perceptions of the thousands of colors we "see." In the future, can we examine the neural structures that produce color vision so as to design and grow neural structures that support vision that senses four primary colors and perceives millions?

If we can grow a neural structure that supports new mental sensations, we may be able to substitute other constituents for neurons while still producing the same results. For example, electronic circuits connected in the same manner as the neurons could potentially simulate the actions of neurotransmitters and receptors. Perhaps the circuits need only reproduce the vast complexity of electric field changes that accompany neuron action.

What are the advantages of replacing neurons? First, the circuits might be more compact, allowing us to stuff more brain power into our skulls; or perhaps they might speed up our mental powers to match the electronic speeds of the digital world.
More profoundly, extending our mental powers by engineered changes would allow us to systematically explore a potential world of mental sensations far beyond those we know today. Thus we might find that all our emotions are combinations of a few basic emotional "atoms." By studying the way the basic emotions combine to produce our present emotions, we could combine them in new ways to create emotions never before experienced. An enormous world of mental sensations awaits our exploration, analogous to the immense number and variety of biological species.

About the Author
William Holmes has a Ph.D. in biophysics and advanced training in artificial intelligence. His major activities have been in the fields of laboratory automation and computerized radiotherapy planning. He was for many years a faculty member in the Biochemistry Department and the Biomedical Computer Laboratory at the Washington University School of Medicine. He presents a detailed exposition on building neural structures in his forthcoming book, Mind over Matter: Building a Limitless Future through Biological Design. His address is 2335 East Seneca Street, Tucson, Arizona 85719. E-mail bholmes2@mindspring.com.

Article Title: Expanding the Human Mind: The Future of the Brain Neurobiology, Electronics, and Other Tools May Give Us Mental Powers That Are Truly Mind-Boggling. Contributors: William Holmes - author. Magazine Title: The Futurist. Volume: 41. Issue: 4. Publication Date: July-August 2007. Page Number: 41+. COPYRIGHT 2007 World Future Society; COPYRIGHT 2007 Gale Group

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