模拟题：雅思阅读经典模拟题（七）b
|
Dr Brinkman， a brain researcher at the Australian National University in Canberra， has suggested that evolution of speech went with right-handed preference. According to Brinkman， as the brain evolved， one side became specialised for fine control of movement （necessary for producing speech） and along with this evolution came righthand preference. According to Brinkman， most left-handers have left hemisphere dominance but also some capacity in the right hemisphere. She has observed that if a left-handed person is brain-damaged in the left hemisphere， the recovery of speech is quite often better and this is explained by the fact that left-handers have a more bilateral speech function.In her studies of macaque monkeys， Brinkman has noticed that primates （monkeys） seem to learn a hand preference from their mother in the first year of life but this could be one hand or the other. In humans， however， the specialisation in function of the two hemispheres results in anatomical differences； areas that are involved with the production of speech are usually larger on the left side than on the right. Since monkeys have not acquired the art of speech， one would not expect to see such a variation but Brinkman claims to have discovered a trend in monkeys towards the asymmetry that is evident in the human brain. Two American researchers， Geschwind and Galaburda， studied the brains of human embryos and discovered that the left-right asymmetry exists before birth. But as the brain develops， a number of things can affect it. Every brain is initially female in its organisation and it only becomes a male brain when the male foetus begins to secrete hormones. Geschwind and Galaburda knew that different parts of the brain mature at different rates； the right hemisphere develops first， then the left. Moreover， a girl's brain develops somewhat faster than that of a boy. So， if something happens to the brain's development during pregnancy， it is more likely to be affected in a male and the hemisphere more likely to be involved is the left. The brain may become less lateralised and this in turn could result in left-handedness and the development of certain superior skills that have their origins in the left hemisphere such as logic， rationality and abstraction. It should be no surprise then that among mathematicians and architects， left-handers tend to be more common and there are more left-handed males than females. The results of this research may be some consolation to left-handers who have for centuries lived in a world designed to suit right-handed people. However， what is alarming， according to Mr. Charles Moore， a writer and journalist， is the way the word 'right' reinforces its own virtue. Subliminally he says， language tells people to think that anything on the right can be trusted while anything on the left is dangerous or even sinister. We speak of left-handed compliments and according to Moore， 'it is no coincidence that left-hand， often develop a stammer as they are robbed of their freedom of speech'. However， as more research is undertaken on the causes of left handedness， attitudes towards left-handed people are gradually changing for the better. Indeed when the champion tennis player Indeed when the champion tennis player Ivan Lendl was asked what the single thing improve his game， he said he would like to become a left-hander. |
