The aging brain: cognitive improvement and decline

As we age, our whole body changes. The same is true for the brain. The most com­mon struc­tur­al change is brain atro­phy as neu­rons, and most­ly con­nec­tions between neu­rons, die. In terms of func­tion­al changes, age-relat­ed cog­ni­tive decline typ­i­cal­ly starts at about forty when the brain pro­cess­ing speed slows down.

Dr. Jer­ri Edwards, whose inter­view you will find at the end of Chap­ter 5, defines pro­cess­ing speed as “men­tal quick­ness”. Younger brains process infor­ma­tion faster than old­er brains. Young and old brains can accom­plish the same tasks but the old­er brains will do so more slow­ly. In our dai­ly life, the speed at which we process incom­ing infor­ma­tion can be cru­cial. This is the case for instance when one is dri­ving and has to assess the sit­u­a­tion and take deci­sion in a 1/45th of a second.

Along with speed of pro­cess­ing, oth­er brain func­tions decline over time. The decline typ­i­cal­ly hap­pens in areas that under­lie our capac­i­ty to learn and adapt to new envi­ron­ments, such as prob­lem-solv­ing in nov­el sit­u­a­tions, mem­o­ry, atten­tion, men­tal imagery, vision, hear­ing, dex­ter­i­ty and flex­i­bil­i­ty. Gen­er­al­ly, get­ting old­er reduces both one’s abil­i­ty to focus and the capac­i­ty for learn­ing new infor­ma­tion. As we age, it takes more and more inhi­bi­tion skills to tune out dis­trac­tions and stay focused. Of course, indi­vid­u­als vary in how and when they expe­ri­ence these decreas­es, but they will even­tu­al­ly occur.

At the same time, grow­ing old­er gen­er­al­ly means that one has acquired more knowl­edge and wis­dom. Indeed, some func­tions do tend to improve with age, such as vocab­u­lary and oth­er word-relat­ed lan­guage skills, pat­tern recog­ni­tion and emo­tion­al self-reg­u­la­tion. In gen­er­al, skills that depend heav­i­ly on accu­mu­lat­ed expe­ri­ence tend to improve. Wis­dom can be seen as the abil­i­ty that enables us to solve prob­lems effi­cient­ly, devel­op empa­thy and insight, and refine moral rea­son­ing. For exam­ple, as judges tack­le more com­plex cas­es, they devel­op wis­dom or an intu­ition for solu­tions and strategies.

In sum, as long as the envi­ron­ment does not change too rapid­ly, we tend to con­tin­ue to accu­mu­late valid wis­dom through­out our lives, yet our capac­i­ty to process and deal with change declines.

Keep learn­ing by read­ing more arti­cles in the Resources sec­tion, and also please con­sid­er join­ing our free month­ly Brain Fit­ness eNewsletter

This new online resource is based on the con­tent from the book The Sharp­Brains Guide to Brain Fit­ness (May 2009, $19.95), by Alvaro Fer­nan­dez and Dr. Elkhonon Goldberg.

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