Sleep can help reinforcelearning in both men and women, such as college students readying for an exam. But to absorb certain kinds of knowledge, known as perceptual learning, men needed a nap whereas women didn't, according to another study presented at the sleep medicine academy's meeting.

In the study, 126 subjects completed a task that required them to identify differences in the movement of dots on a screen. The subjects then underwent some training in the task and were tested again to see how much they had learned. Men only learned after a nap. Women learned whether they napped or not. 'It may be the case that women are better suited for tasks requiring sustained perception, jobs like air-traffic controllers or radiologists who are reading MRIs,' says Elizabeth McDevitt, a study coordinator at the University of California, San Diego and the lead author of the study.

Life changes, including pregnancy and menopause, can wreak havoc on women's sleep. Overall, however, men wake up more often during the night, partly because of their greater risk for obstructive sleep apnea, researchers say.

Some researchers say some women may not feel they're getting a good night's sleep because sleep studies may not be seeing the whole picture when it comes to insomnia. New studies using PET scans have shown that in patients with insomnia, glucose metabolism is elevated in some parts of the brain. So even when they're asleep 'their brain isn't completely shut off,' says Dr. Buysse. Women are about 50% more likely to have insomnia than men. Other researchers say women, more than men, tend to suffer from depression and anxiety disorders, which can lead to insomnia.

Andrea Petersen

• awaken [ə´weikən] v.唤起，叫醒 (初中英语单词)


• amount [ə´maunt] n.总数；数量 v.合计 (初中英语单词)


• factor [´fæktə] n.因素；原动力；要素 (初中英语单词)


• instance [´instəns] n.例子，实例，例证 (初中英语单词)


• pittsburgh [´pitsbə:g] n.匹兹堡 (初中英语单词)


• partner [´pɑ:tnə] n.伙伴 v.同….合作 (初中英语单词)


• research [ri´sə:tʃ] n.&vi.调查；探究；研究 (初中英语单词)


• physical [´fizikəl] a.物质的；有形的 (初中英语单词)


• assistant [ə´sistənt] n.助手；助理；助教 (初中英语单词)


• security [si´kjuəriti] n.安全；证券；抵押品 (初中英语单词)


• derive [di´raiv] v.得出；衍生 (初中英语单词)


• academy [ə´kædəmi] n.专科学校；学会；协会 (初中英语单词)


• annual [´ænjuəl] a.每年的 n.年刊 (初中英语单词)


• compound [kəm´paund] n.&a.混合(的) v.合成 (初中英语单词)


• healthy [´helθi] a.健康的 (初中英语单词)


• therefore [´ðeəfɔ:] ad.&conj.因此；所以 (初中英语单词)


• contrast [´kɔntrɑ:st] n.对比 v.使对比(照) (初中英语单词)


• associate [ə´səuʃieit] v.联合a.同伴的n.伙伴 (初中英语单词)


• medical [´medikəl] a.医学的；医疗的 (初中英语单词)


• whereas [weər´æz] conj.鉴于；因此；而 (初中英语单词)


• journal [´dʒə:nəl] n.日记；日报；杂志 (初中英语单词)


• international [,intə´næʃənəl] a.国际的，世界的 (初中英语单词)


• complain [kəm´plein] vi.抱怨，叫屈；控诉 (初中英语单词)


• investigation [in,vesti´geiʃən] n.调查(研究) (初中英语单词)


• performance [pə´fɔ:məns] n.履行；行为；工作 (初中英语单词)


• computer [kəm´pju:tə] n.计算机；电子计算器 (初中英语单词)


• reaction [ri´ækʃən] n.反应(力) (初中英语单词)


• learning [´lə:niŋ] n.学习；学问；知识 (初中英语单词)


• absorb [əb´sɔ:b] vt.吸收；吸引 (初中英语单词)


• identify [ai´dentifai] vt.认出；鉴定；验明 (初中英语单词)


• movement [´mu:vmənt] n.活动；运动；动作 (初中英语单词)


• screen [skri:n] n.银幕 vt.遮蔽 (初中英语单词)


• reading [´ri:diŋ] n.(阅)读；朗读；读物 (初中英语单词)


• california [,kæli´fɔ:njə] n.加利福尼亚 (初中英语单词)


• partly [´pɑ:tli] ad.部分地；不完全地 (初中英语单词)


• depression [di´preʃən] n.沮丧，抑郁；萧条 (初中英语单词)


• anxiety [æŋ´zaiəti] n.挂念；渴望；焦虑的事 (初中英语单词)


• regularly [´regjuləli] ad.有规律地；经常地 (高中英语单词)


• classic [´klæsik] a.第一流的 n.杰作 (高中英语单词)


• behavior [bi´heiviə] n.举止，行为 (高中英语单词)


• so-called [´sou ´kɔ:ld] a.所谓的，号称的 (高中英语单词)


• harvard [´hɑ:vəd] n.哈佛大学 (高中英语单词)


• exposure [ik´spəuʒə] n.暴露；曝光(时间) (高中英语单词)


• eliminate [i´limineit] vt.消除；淘汰 (高中英语单词)


• saying [´seiŋ, ´sei-iŋ] n.言语；言论；格言 (高中英语单词)


• critical [´kritikəl] a.批评的；关键性的 (高中英语单词)


• reinforce [,ri:in´fɔ:s] vt.增援 n.加固物 (高中英语单词)


• learned [´lə:nid] a.有学问的，博学的 (高中英语单词)


• seeing [si:iŋ] see的现在分词 n.视觉 (高中英语单词)


• increasingly [in´kri:siŋli] ad.日益，愈加 (英语四级单词)


• objective [ɔb´dʒektiv] a.客观的 n.目标 (英语四级单词)


• bedtime [´bedtaim] n.就寝时间 (英语四级单词)


• trying [´traiiŋ] a.难堪的；费劲的 (英语四级单词)


• uncommon [ʌn´kɔmən] a.非常的，非凡的，罕见的 (英语四级单词)


• perception [pə´sepʃən] n.感觉；概念；理解力 (英语四级单词)


• chronic [´krɔnik] a.慢性的；剧烈的 (英语六级单词)


• biological [,baiə´lɔdʒikəl] a.生物学(上)的 (英语六级单词)


• extended [iks´tendid] a.伸长的；广大的 (英语六级单词)