The amount of sleep we get can impact our mental health in later life, a study conducted by the University of Londonhas warned. Sleeping too little or for too long disrupts how we think and can age the brain by up to seven years, the findings show.
Getting less or more than the six to eight hours recommended sleep increases the speed of cognitive decline and affects abilities such as reasoning and vocabulary.
The researchers warned that worsening brain function could also triggerphysical decline and early death.
University of London scientists showed how changes in sleep over a five-year period in late middle age affects cognitive function in later life.
The six standard tests measured memory, reasoning, vocabulary, phonemic fluency, semantic fluency and global cognitive status.
Researchers found the ideal amount of sleep duration of seven hours per night resulted in the highest score for every cognitive measure, followed closely by six hours of nightly sleep.
Around seven hours of good quality sleep is fundamental to human functioning and well-being, according to the study.



英国伦敦大学一项研究日前发出警告，睡眠的多与少会影响人类晚年的精神健康。研究发现，睡的太多或不足都会扰乱人的思维，并最高可使大脑衰老7岁之多。


成人每日正常睡眠时间应为8小时，睡眠时间超过或者低于推荐值都将加快认知衰减的速度，从而影响人在诸如推理、语言应用等方面的能力。

研究人员警告，大脑功能的持续恶化还将引发身体功能的衰退和早逝。

伦敦大学科学家（通过测试）向人们展示了5年间睡眠时长的变化对中年人认知能力的影响。

6项测试标准包括：记忆力、推理、词汇、语音流畅度、语义流畅度以及全球认知水平。

结果发现，每晚睡眠7小时的中年男女在所有认知能力测试中得分最高，其次是每晚睡眠6小时的中年男女。

根据这项调查，每天7个小时左右的高质量睡眠是人体各项功能正常和健康的基础。

• amount [ə´maunt] n.总数；数量 v.合计 (初中英语单词)
• mental [´mentl] a.精神的；心理的 (初中英语单词)
• sleeping [´sli:piŋ] n.&a.睡着(的) (初中英语单词)
• function [´fʌŋkʃən] n.机能；职责 vi.活动 (初中英语单词)
• physical [´fizikəl] a.物质的；有形的 (初中英语单词)
• vocabulary [və´kæbjuləri, vəu-] n.词汇；词汇量 (初中英语单词)
• measure [´meʒə] n.量度；范围 vt.测量 (初中英语单词)
• fundamental [,fʌndə´mentl] a.基本的 n.原理 (初中英语单词)
• reasoning [´ri:zəniŋ] n.推理，评理 a.推理的 (高中英语单词)
• nightly [´naitli] a.&ad.每夜(的) (英语四级单词)
• impact [´impækt] n.影响，作用；冲击 (英语六级单词)
• trigger [´trigə] n.扳机 vt.触发，启动 (英语六级单词)
• duration [djuə´reiʃən] n.持久；持续期间 (英语六级单词)
• well-being [´wel´bi:iŋ] n.幸福；健康；福利 (英语六级单词)