人老大脑萎缩，但工作照旧
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Scientists know that our brains shrink with aging, but does less gray matter really matter? Apparently not, according to a new study of 446 people in Australia. "We found that, on average, men aged 64 years have smaller brains than men aged 60," said Helen Christensen of the Australian National University. "However, despite this shrinkage, cognitive functions -- like memory, attention and speed of processing -- are unaffected." The conclusion was based on questionnaires and brain scans. The study, announced Friday, yielded another surprise. Previous studies had indicated that higher levels of education or continuing intellectual activity could serve as a sort of Pilates for the brain, keeping an aging mind fit. "Our findings do not support these beliefs," Christensen said. "In the present study, we found no relationship between brain shrinkage and education level." Older minds do sometimes fail, of course, owing to conditions such as Alzheimer’s that scientists are only beginning to understand. Little is known about brain shrinkage, too. "It is known that the brain shrinks over the course of a person’s life, although the exact trajectory is not well understood, and there are huge individual differences," Christensen said. 科学家们已经得知，随着年龄的逐渐增长，人们的大脑也会相应地老化，发生萎缩。而澳大利亚6月10日公布的一项最新研究结果却显示，大脑的萎缩并不会影响人们的脑部功能。 据美国“生活科学”6月10日报道，澳大利亚国立大学的研究人员通过分析446人的脑部扫描图以及研究了这些人的问卷调查结果后，得出了上述结论。研究者之一的海伦·克里斯坦森表示：“我们发现，平均起来，64岁的男性其大脑要比60岁的男性的大脑小一些，然而，大脑的一些认知功能，如记忆、注意力以及处理问题的速度等，却都没有因此而受到影响。” 以前曾有研究显示，接受高水平教育或是持续进行脑力活动可以被认为是一种脑部锻炼，能使逐渐老化的大脑保持健康。克里斯坦森说：“我们的研究结果并不支持以前的这些观点，我们在研究中发现大脑的萎缩与受教育水平两者之间没有联系。” 报道说，由于老年痴呆症等一些情况的存在，逐渐老化的大脑有时确实会出现一些问题。但是目前，人们对老年痴呆症的了解也是刚刚才开始；而人们对于脑部萎缩也是知之甚少。对此，克里斯坦森也表示，虽然人们对脑部萎缩发生的准确轨迹并不十分了解，而且个体之间也存在着很大的差异，但目前据人们所知脑部萎缩的过程会贯穿一个人的一生。 |
