多走路有助于大脑

今天NYT上的报道对中年人都应该有启示, 这个关于锻炼如何影响大脑海马区域,尤其走路会帮助海马区域的增大,大概是近年来看到的最有意思的发现之一.

海马区(hippocampus)简介(ZT):

心理学家与神經學家对海马的作用存在争论，但是都普遍认同海马的重要作用是将经历的事件形成新的记忆 (情景记忆或 自传性记忆). 一些研究学者认为应该将海马看作对一般的 陈述性记忆起作用内侧颞叶记忆系统的一部分。 (陈述性记忆指的是那些可以被明确的描述的记忆，如“昨天晚饭吃了什么”这样的关于经历过的事情的情景记忆，以及“北京是中国的首都”这样的关于知识的概 念记忆).
有迹象显示，虽然这些形式的记忆通常能终身持续，在一系列的记忆强化以后海马便中止对记忆的保持。海马的损伤通常造成难以组织新的 记 忆(顺行性失忆症), 而且造成难以搜索过去的记忆 (逆行性失忆症)。尽管这样的逆行性效果通常在脑损伤的很多年之前就开始扩展，一些情况下相对久远一些的记忆能够维持下来。这表明海马将巩固以后的记忆转 入了脑的其他的部位。但是，旧的记忆是如何储存的要用实验来检测的话存在一些难点。另外，在一些逆行性失忆症案例中，在海马遭受损伤的数十年前的记忆也受 到了影响，导致了这一关于旧的记忆的观点的争议。
海马的损伤不会影响某一些记忆，例如学习新的技能的能力（如学习一种乐器），将设这样的能力依靠的是另外一种记忆(程序記憶)和不同的脑区域。有迹象表明著名的病人HM(作为治疗癫痫病的手段他的内侧颞叶被切除) 有组织新的概念记忆的能力

NYT ZT:

Taking Your Brain for a Walk

By TARA PARKER-POPE

Steve Johnson for The New York Times

Regular walking isn’t just good for the dog. It’s also good for your brain. As Paula Span reports:

In a study published on Jan. 31 in The Proceedings of the National Academy of Sciences, researchers randomly assigned 120 healthy but sedentary men and women (average age mid-60s) to one of two exercise groups. One group walked around a track three times a week, building up to 40 minutes at a stretch; the other did a variety of less aerobic exercises, including yoga and resistance training with bands.

After a year, brain scans showed that among the walkers, the hippocampus had increased in volume by about 2 percent on average; in the others, it had declined by about 1.4 percent. Since such a decline is normal in older adults, “a 2 percent increase is fairly significant,” said the lead author, Kirk Erickson, a psychologist at the University of Pittsburgh. Both groups also improved on a test of spatial memory, but the walkers improved more.

Other walking studies suggest spending time in a natural setting like walking in a park reduces brain fatigue and that for people in their 60s, regular walking appears to lower the risk of dementia.