Philosophers throughout the millennia have spent much effort in trying to define 'the mind' and even today it's not all clear what exactly it is. Some would say that the mind is the seat of the soul and others that it is nothing more than the sum total of one's experience, which could also be called 'consciousness'. For the sake of simplicity. I am calling 'mind' here all that which can be said to be primarily experienced in the head - personality, thinking process, intellectual capacity, moods as in feeling 'up' or 'down', and emotions such as love and fear.
Ironically perhaps for the 'seat of feeling', the brain has no pain receptors, so after cutting through the skull with local anesthetic, brain surgery can be done without anesthetic and the patient conscious. The brain seems a well-defined organ but some of the nerves within it are over a meter long......so where does the brain end and the body begin? one could say the brain ends at our fingertips, working on a computer terminal, for example, that's how far the brain's messages go ( biologically, at least. Technically, the brain is about three pounds of pink and grey wet matter, 90 percent water.
From an engineering and computational point of view, the brain is the most complex, structure known as it is thought to have 100billion cells and 100,000 billion possible connections.
With training, people with a certain aptitudes can perform remarkable mathematical feats, as in the case quoted in Supernature 11, of Aitken who, when asked to turn 4/47 into a decimal he replied in four seconds with 'point 0851063829782340425531914', then he paused for and continued '98361702127659574468',and that's the repeating point.
It starts again then at 085.' Aitken who was a professor of mathematics at the University of Edinburgh, is obviously a smart guy, but to accomplish these feats, he had to train his memory, which everyone can do. as far as can be guessed, good memory was evolutionarily advantageous in the days when we needed to communicate survival information, history and custom from generation to generation, but had no writing with which to do di. the memorizers were the libraries. Then, as now the brain constantly modifies itself, learning more each day, using and re-using connections, finding new ways to do things.
As we know, if children are started early enough with intense teaching, they can absorb a phenomenal amount of information by their teens. why we have this huge mental capacity and whatever its evolutionary past may be, it is a delight for humans to exercise and test our brains. We take pride in being able to fix the car, finish the crossword, win an argument, put our political point, pass the exam and so on. But the brain is more than our valid tool, it is our friend, our confidant, our security and our home.
We more than remember and compute, we feel. Tears pop out of our eyes; rage turns our face red. all this may be evolutionary advantage - if we didn't feel angry when someone stole our last fish, we wouldn't fight to get it back and maybe we would have starved; if we didn't feel love, who would take care of the babies? Emotions may not seem so great when you're sitting on the sofa, tears rolling down the cheeks because your partner has just moved out, but it's a mechanism, feeling, loss, which accentuates its other side - feelings great together, which is the glue that keeps us in the evolutionary-favourable pair-bonding and social groups.
Working in small or large teams, whether specialist or not, means we can get more done more easily. That's one reason why we are where we are - in control of the world. These days the brain is under tremendous pressure. Was it designed, I wonder, to do what a typical day in a modern city requires of it? We all wake up to the news - which is usually bad, if not horrifying ( and depressing), then the post arrives, with more bills we can't pay. The drive to work packed with too many people in an underground train.
Breathing in the polluted air, commands come at us 'walk' or don't walk' the signals say. The commands continue when we get to the workplace, in which we have to watch our mouths and our moves or we might get made redundant. Whatever politics and unpleasantness is thrown at us, we have to get on with it, or there's no money on payday.
Flickering through magazines during our ten-minute tea break, we read articles telling us to be better mothers, fathers, lovers, slimmers, dressers, lookers achievers. We start feeling guilty. On the way home from work we stop at the supermarket. More decisions. We pick up an apple - is it fresh enough? has it been waxed, irradiated, or sprayed with chemicals' We pick up a yogurt' - has the out-of-date- ticked expired, what's in it? We look in the freezer - will one of these products be acceptable to all members of the family or is someone going to say , ' I don't eat that'? Temptation looms in the checkout, then the bill arrives. we go home and watch TV. We cry at a sad old movie, then watch horrified at the news pictures of a plane crash.
Half an hour later we're sitting on the edge of our seats , cheering on out team in football. Then the ads come on and scream 'Buy me Buy me!. We think about tomorrow, put a load of wasting in the machine and iron a couple of shirts, by the time we get into bed, we're exhausted - mentally as much as physically. Was the mind designed for all this, or was it meant to look out over a clear night sky and ponder the nature of the universe?
It would be convenient for scientists if all brains were the because it would be much easier to establish a 'normal' brain from which others could be judged. But it's not that simple - every brain is different. Nevertheless, the measuring goes on. Not only do we have static computerized axial tomography (CAT) scan photos, we've got moving living images through positron-emission tomography (PET) , magnetic resonance imaging (MRI) and superconducting quantum interference devices (SQUIDS).
A great deal has ben heard this past couple of decades, about neurotransmitters or brain chemicals. You hear the word serotonin, noradrenaline and so on bandied around as if they were every day things we knew everything about, especially as many modern drugs are intended to mimic them in some way. In fact the only synapse in the mammalian central nervous system, where scientists are certain what the transmitter is, is in the case of the acetylcholine (ACh) synapses between the motor neuron axon collaterals and interneurons. Except in this case, scientists have been unbale to make pure cultures of other synapses and although the action of ACh is understood at neuromuscular junctions, how the ACh circuits in the brain is still not known.
Books on the brain are full of words like presumably, probably and may, and expressions like 'one must be very careful about drawing conclusions.' This isn't out of misplaced lack of confidence, but actual fact - we don't know how the brain's chemicals work. According to Richard Thompson in The Brain, ' we are only beginning to understand the functional circuitry of the brain'. Apparently, ' the most is known about the least common transmitters in the brain', dopamine and norepinephrine, and the neurons that contain then - but they account for any a few percent of total neurotransmitters in the brain. Besides transmitters, many neuron terminals also contain peptides - which could act as transmitters, but not a great deal is known about their function.
Human beings have been building up a library of information on opium for a least five thousand years , science discovered only relatively recently that the brain produces opiates in the neurons and the pituitary, which, like morphine, alleviate pain and produce pleasurable sensations.
We know there are several opiate receptors on the neurons in the brain but Thompson admits 'little' is really known about the possible differential functions of the different brain opioids and the different opioid receptors. What little we know about opiates has been highlighted by the very recent discovery, by Dr Goldstein at Stamford University, of dynorphin which is over 200 times more potent than morphine. The mind boggles!
Scientifically, there's a world of difference between knowing that a certain chemical can effect a certain change, and knowing how it does it. Brain science is at the stage of rec organising that certain brain chemicals elicit a certai9n response, and mostly they seek to inhibit or encourage the flow of these chemicals. However, let us not overestimate what is known or how ell understood modern drugs are. According to Thompson, on the drug, used to treat manic depression, for example, 'the reasons for Lithium's effectiveness are still largely obscure'.
Reference:The Fragrant Mind : Valerie A Worwood
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