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2010年6月23日 星期三

A New Brain for a New Century?

The recent political debate has prompted me to explore the mysteries of the human brain: how it works, how it may affect our emotions, our thinking and through our thinking, our action through our memory, belief systems and how the latter may themselves be affected by the new environment in which the human race has to live. I read a chapter of "The Naked Brain" (How the Emerging Neuorscience is changing How we Live, Work and Love (2006) by Richard Restak, M.D. He has written extensively on the functioning of the human brain e.g. Brainscapes (What Neuroscience has learned about the structure, function and abilities of the Brain (1995) Mysteries of the Mind (2000), The Secret Life of the Brain (2001) Poe's Heart and the Mountain Climber (Exploring the Effect of Anxiety on Our Brains and Our Culture) (2004), Mozart's Brain and the Fighter Pilot (Unleashing Your Brain's Potential) (2005), The Brain has a Mind of its Own (Insights from a Practising Neurologist).(2005).  It is the final chapter of his book in which he takes a look at what brain scientists are doing and peeps into the future to see what kind of scenario may emerge in the next twenty or thirty years. What follows is taken largely from this "Afterword" of his book.


To Restak, while our brain has not changed in size for the last 200,000 years, genetic research has discovered in 2005 variants of two genes which control brain development which may enhance higher intelligence or quicker thinking. That means we have not yet reached the final stage of brain development. There is still room for change of the human brain. But more importantly, we now know that culture exerts a more powerful influence on our intellectual and emotional development than strictly biological factors. The average IQ has climbed 24 points since 1918 due possibly to healthier diet, better education and perhaps the feeding of higher information content to our brain. Restak thinks the last the most crucial. Because of this, we can expect the rate of technological innovation to accelerate. According to Ray Kurzweil, writing in The Singularity is Near: When Humans Transcends Biology, we may experience 20,000 years of progress (measured by the rate of progress in 2000) or about 1000 times that in 20th century!He further predicts that by "the 2030s, the non-biological portion of our intelligence such as computers and prosthetic devices will predominate. By the 2040s, it will be billions of times more capable than the biological protion." That awaits to be seen.


In the meantime, we do know that the revolution in information technology is already radically affecting the way we live our lives. I cannot now imagine life without the internet with which I just communicated with my wife in America and my elder daughter in China and my younger daughter in Spain despite the tremendous geographical distances separating us. I can see them. They can see me. And we can talk through the computer screen and the mikes on the tiny video camera clipped to top of my computer screen! To Restak, this is already "altering our attitudes, our ways of relating to each other, the speed and cadence of our speech and even our attitude toward work and leisure.".


Another discovery by our brain scientists is that we now know that our brain cannot be understood by focusing on individuals because we are social creatures: we need to belong. Such a need is as basic as our need for food and for oxygen. Attachment and nurturing associations with other people have been crucial to our lives since birth and therefore we are acutely sensitive to each other's social signals and that is why exclusion, ridicule, separation, divorce, bereavement hurt so much and why attraction, altruism, identification, communication, compassion and co-operation between people are so important for our positive development.


We have now the kind of technology to tell us the chances of recovery of a patient and the likely consequences of a biological survival from brain scans. The question we ask is no longer whether "a patient is dead or alive" but "whether this life is worth living". This latter is a much more tricky question. We now know that even a vastly atrophied brain at birth does not necessarily mean that a meaningful life cannot be led. We now have evidence that an infant whose brain scan revealed that he merely had a thin line of consciousness which is tiny tiny fraction of what a "normal" child has finished high school, married, is now working as a bank teller and has children. We should never underestimate the ability of our "immature" brain to colonize other brain areas to serve equivalent functions performed by other sectors of a "normal" brain! What qualifies as an "abnormality" in a given scan may not be so if placed in the context of a different and vaster data base and if subjected to different statistical thresholds. "If the database or thresholds are altered, what initally appeared as an overly active area may fade into the general background of the image." Contexts is everything in an interpretation, in science as in art.


Whenever we try to link human traits and performances with specific locations within the brain, the context is extremely important. Douglas Hofstadter said in a symposium on the brain, "People yearn to find 'the' neural correlate of an emotion or even a creative thought. That hope seems about as silly as trying to find the key to the greatness of a novel by closely examining the typographical symbols that compose it.". Restak concludes that while brain science has much to contribute to our lives, "it cannot be allowed to define us.".


Will or can future generations be made smarter and more sociable? To Restak, to have better mental performance, we need to improve focus, concentration, memory and mental endurance. Focus and concentration help us remain centred on the task in hand and memory help us link our present to our past knowledge base whilst endurance enables us to maintain our performance through a longer period of time instead of being overly tired out and therefore lose concentration. Drugs available for enhancing these 4 functions have already been available for years e.g. amphetamine and such stimulants as Ritalin can enhance focus, concentration, memory and mental endurance but these are controlled drugs and can be prescribed for specific disorders as "attention deficit disorders" (ADD) and is addictive because of habituation, the patient requiring more and more as time goes on to achieve equivalent effect later. Yet they are now being increasingly prescribed for students. A survey at an Ivy Leaque college places the number of users at nearly 60%! Provigil (modafinil) is now routinely used by business people, entertainers, military personnel and others to remain fully awake for long periods and sometimes for days at times. This drug was originally developed for the irresistible drowsiness of narcolepsy and shift-work-induced drowsiness. Should these drugs be controlled?  Certainly, those taking them will be placed at an unfair advantage against those who don't when all of them have to undergo certain stringent competitive tests, exams etc requiring prolonged periods of high concentration in the same way that steroid is banned for Olympic athletes. There is little doubt that mood altering drugs help relieve the symptoms of grief, fatigue, lack of focus, mood variation, forgetfulness, distraction and other "unproductive" mental states.  Yet many people are now using these drugs , not to treat specific disorders but merely as "life-style" and "personality-changing" purposes. Some people think there is no problem. They think of "cognitive enhancers" as just a technical aid helping to improve learning ability "like providing a positive learning environment and practising good study habits" e.g bioethicist Thomas M Murray asks: " Is popping a pill a 'quick fix' instead of working toward improving cognitive ability through reading.?" If we cannot sleep, we take sleeping pills and in the morning, we take alertness enhancing drugs to bring us up to our "normal" acitivity pace. Should we undergo normal "grief" upon the death of someone dear to us? Or should we take a tranquilizer before the funeral and an anti-depressant during the period of bereavement in the weeks that follow?


We now know how to predict who is an introvert and who is an extrovert by performing fMRI upon various subjects: upon being shown a positive word, an extrovert's brain shows increased activation in the anterior cingulate,  as found by neuroscientist B W Hass of SUNY. He found that behaviorally, an extrovert tends to dwell longer on the positive and de-empahsize the negative in the same manner as positive neural messages stay longer in their anterior cingulate. That is why we enjoy their company. In the same manner, the more adept persons are in reading "social" clues, the less effort they need to activate their prefrontal cortex. We say that such people have high social intelligence. Brain scanning techniques are already being used by the American military in selecting their officers in their training of the Special Forces (SF) because they need officers who remain resilient under emotionally trying circumstances. When shown a series of faces displaying signs of fear and anger, the SF soldiers show heightened responses in the amygdala (closely associated with fear control and emotional arousal) and also increased activity in the anterior cingulate and inferior frontal cortex, both associated with emotional regulation. The scans therefore show that the SF soldiers show "normal" reaction to fear just like untrained volunteers, but they have better control of their fear "response". 


Brain research have also indicated that addiction to drugs, addiction to alcohol, addition to food, (leading to obesity) addiction to gambling, addiction to computer games may be treated as specific instances of a more general addiction involving both arousal and craving which can be measured and to the addiction for the release of dopamine (a brain-produced pleasure hormone)! Other research have indicated that we acitivate the same area of our brain when we attribute emotions to ourselves as those used when we attribute emotions to others. We have what has been called "mirror cells" which may be the physiological basis for the Confucian "empathy/compassion" and  the Christian "love". As I previously argued, this may be the ultimate biological basis for the development of the kind of altruism advocated by the various religions. 


As our knowledge of the functioning of our brain advances with our brain scanning technology and the development of newer and newer mood altering drugs, the question of their use and control becomes all the more urgent. To Restak, our challenge is this: "we can employ this emerging new knowledge about social neuroscience to advance human freedom within the neurosciety or we can allow irresponsible people to use this knowledge in ways that are not always to our advantage" eg. in advertisements, pop culture, political spin, movies and television. As always, scientific knowledge is always neutral. It really depends on ourselves whether we wish to apply our knowlege for good or for evil. That is a question which science cannot answer for us.


2 則留言:

  1. You've brought up an interesting issue here: Can we switch our minds and thoughts? And by what means, and what kind of brain surgery shall we perform? I'm satisfied with my present state of mind, then there is no need to perform any kind of brain surgery. Hahaha...
    [版主回覆06/23/2010 20:03:00]Ah, I have met my match! An eternal optimist! I am so pleased for you!

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  2. especially the emotionally provocative power of human brain  is changing, I don't know  it's good or not
    [版主回覆06/24/2010 16:59:00]There is always the risk of abuse. But to me, knowledge of how brain function is always preferable to ignorance. With knowledge comes the possibility of control and management of unruly emotions in the interest of order. Otherwise, we may be overwhelmed by the dark side or the shadow of our psyche, without even being aware of such risk!

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