??study suggests link between long sleep times,?cognitive?loss

研究表明，睡得太久与认知能力的下降存在关联

scientists have long said getting a good night’s sleep is important to your health. the u.s. national institute of health says?lack of sleep?may even increase the risk of impaired brain activity, or?cognitive decline, and alzheimer’s disease.

科学家们一直认为，晚上睡个好觉对你的健康很重要。美国国家卫生研究院表示，睡眠不足甚至可能会增加大脑活动受损、认知能力下降和阿尔茨海默病的风险。

now, an american team of scientists reports that too much sleep might be similarly linked to such conditions.?researchers at washington university school of medicine in st. louis, missouri, did the sleep study.?

现在，一个美国科学家团队报告称，睡眠过长可能也会导致类似的情况。位于密苏里州圣路易斯的华盛顿大学医学院的研究人员开展了这项睡眠研究。

the study examined 100 adults who had been under medical observation for cognitive ability, the ability to think, for an average of 4.5 years. the average age of the study subject was 75. eighty-eight of the group had been identified as free of cognitive?impairment, or damage. eleven subjects were judged very mildly impaired, and one was identified as mildly impaired.

该研究对100名成年人进行了平均4.5年的认知能力（即思考能力）医学观察。研究对象的平均年龄为75岁，其中88人经确认不患有认知障碍或损伤，11位受试者被判定为轻度受损，1人被认定为轻度受损。

during the study, they were asked to complete several tests for signs of cognitive decline. the tests are combined into a cognitive score – the higher the score, the better. they also wore electroencephalography (eeg) devices for four to six nights to measure their brain activity during sleep.

在研究期间，受试者被要求完成几项认知衰退迹象的测试。这些测试被合并成一个认知分数——分数越高表示认知能力越好。他们还需要在4至6个晚上佩戴脑电图设备，以测量他们在睡眠时的大脑活动。

overall, cognitive scores declined for those who slept less than 4.5 hours or more than 6.5 hours per night — as measured by eeg. but the scores stayed the same for those in the middle of the range.

总体而言，通过脑电图测量，每晚睡眠少于4.5小时或多于6.5小时的人认知能力得分有所下降，但是那些睡眠时间处于4.5小时和6.5小时之间的人的分数保持不变。

dr. brendan lucey is director of the washington university?sleep medicine center?and led the research. he said, “our study suggests that there is a middle range, or ‘sweet spot,’ for total sleep time” for best cognitive performance.?”short and long sleep times were?associated?with worse cognitive performance, perhaps due to?insufficient?sleep or poor sleep quality, ” lucey added.

华盛顿大学睡眠医学中心的主任布伦丹·路西主导了这项研究。他说：“我们的研究表明，总睡眠时间存在一个中间区间，也就是‘最佳点’。”路西补充道：“睡眠时间过短或过长都会导致认知表现的下降，这可能是睡眠不足或睡眠质量差所导致的。”

greg elder is a sleep researcher at northumbria university in new castle, britain. he was surprised about the findings that sleeping longer than 6.5 hours was linked with cognitive decline. he?wrote?in the conversation, “this is low when we consider that older adults are?recom

mended?to get between?seven and eight hours?of sleep every night.”

英国纽卡斯尔诺森比亚大学的睡眠研究员格雷格·埃尔德对睡眠时间超过6.5小时与认知能力下降有关的研究结果感到惊讶。他在《对话》杂志中写道，“考虑到我们一般建议老年人每晚睡7至8小时，那么6.5小时的标准就太低了。”

elder also noted that the research did not consider other information about the individuals studied, including their general health or economic conditions.

埃尔德还指出，这项研究没有考虑到受试者的其他信息，包括他们的一般健康状况或经济状况。

other studies have shown that lack of sleep was linked with cognitive decline. a small 2018 study?published?in the proceedings of the national academy of sciences found that losing just one night of sleep led to an increase in beta-amyloid production. beta-amyloid is a?metabolic?waste product found in between brain cells. it has been long linked to brain disorders, such as alzheimer’s disease.

其他研究表明，睡眠不足与认知能力下降有关。2018年发表在《美国国家科学院院刊》上的一项小型研究发现，仅仅一夜不睡就会导致β-淀粉样蛋白的生成增加，β-淀粉样蛋白是一种存在于脑细胞之间的代谢废物，它与阿尔茨海默症等脑部疾病密切相关。

the national sleep foundation?advises?that healthy adults need between seven and nine hours of sleep per night. babies, young children, and teens need even more sleep for their growth and development. and people over 65 should also get seven to eight hours per night, the foundation says.

美国国家睡眠基金会建议，健康的成年人每晚需要7至9个小时的睡眠，婴幼儿和青少年需要更多的睡眠以促进成长与发展。该基金会表示，65岁以上的人每晚也应该有7至8小时的睡眠时间。

one unanswered question from the washington university study is whether increasing sleep time for short sleepers would help their cognitive performance.?but lead writer lucey said each person’s sleep needs are individual. if people feel rested, there is no need to change how they sleep. but those who are not sleeping well should know that sleep problems often can be treated, lucey said.

华盛顿大学这项研究未能回答的一个问题是，增加短睡眠者的睡眠时间是否有助于他们的认知能力的提升。该研究的主要作者路西表示，每个人的睡眠需求都是因人而异的，如果自己感到休息好了，就没有必要刻意改变睡眠方式，但那些睡眠不佳的人应该知道，睡眠问题通常是可以治疗的。

(全文共542个词，黑体单词为考研重难点词汇)

重难点词汇：

cognitive?[?kɑ?ɡn?t?v] adj. 认知的；感知的

insufficient?[??ns??f??nt] adj. 不充分的；不足的

metabolic?[?met??bɑ?l?k] adj. 代谢的；新陈代谢的

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