多走路有助於大腦

今天NYT上的報道對中年人都應該有啟示, 這個關於鍛煉如何影響大腦海馬區域,尤其走路會幫助海馬區域的增大,大概是近年來看到的最有意思的發現之一.

海馬區(hippocampus)簡介(ZT):

心理學家與神經學家對海馬的作用存在爭論，但是都普遍認同海馬的重要作用是將經曆的事件形成新的記憶 (情景記憶或 自傳性記憶). 一些研究學者認為應該將海馬看作對一般的 陳述性記憶起作用內側顳葉記憶係統的一部分。 (陳述性記憶指的是那些可以被明確的描述的記憶，如“昨天晚飯吃了什麽”這樣的關於經曆過的事情的情景記憶，以及“北京是中國的首都”這樣的關於知識的概 念記憶).
有跡象顯示，雖然這些形式的記憶通常能終身持續，在一係列的記憶強化以後海馬便中止對記憶的保持。海馬的損傷通常造成難以組織新的 記 憶(順行性失憶症), 而且造成難以搜索過去的記憶 (逆行性失憶症)。盡管這樣的逆行性效果通常在腦損傷的很多年之前就開始擴展，一些情況下相對久遠一些的記憶能夠維持下來。這表明海馬將鞏固以後的記憶轉 入了腦的其他的部位。但是，舊的記憶是如何儲存的要用實驗來檢測的話存在一些難點。另外，在一些逆行性失憶症案例中，在海馬遭受損傷的數十年前的記憶也受 到了影響，導致了這一關於舊的記憶的觀點的爭議。
海馬的損傷不會影響某一些記憶，例如學習新的技能的能力（如學習一種樂器），將設這樣的能力依靠的是另外一種記憶(程序記憶)和不同的腦區域。有跡象表明著名的病人HM(作為治療癲癇病的手段他的內側顳葉被切除) 有組織新的概念記憶的能力

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.