Sharp Brains: Brain Fitness and Cognitive Health News

Neuroplasticity, Brain Fitness and Cognitive Health News


Promoting Healthy, Meaningful Aging Through Social Involvement: Building an Experience Corps

(Editor’s note: Path­ways respon­si­ble for higher-order think­ing in the pre­frontal cor­tex (PFC), or exec­u­tive cen­ter of the brain, remain vul­ner­a­ble through­out life—during crit­i­cal early-life devel­op­men­tal win­dows, when the PFC fully matures in the early 20s, and finally from declines asso­ci­ated with old age. At all ages, phys­i­cal activ­ity and PFC-navigated social con­nec­tions are essen­tial com­po­nents to main­tain­ing brain health. The Expe­ri­ence Corps, a community-based social-engagement pro­gram, part­ners seniors with local schools to pro­mote purpose-driven involve­ment. Par­tic­i­pat­ing seniors have exhib­ited imme­di­ate short-term gains in brain regions vul­ner­a­ble to aging, such as the PFC, indi­cat­ing that peo­ple with the most to lose have the most to gain from envi­ron­men­tal enrichment.)

Over the last decade, sci­en­tists made two key dis­cov­er­ies that reframed our under­stand­ing of the adult brain’s poten­tial to ben­e­fit from life­long envi­ron­men­tal enrich­ment. First, they learned that the adult brain remains plas­tic; it can gen­er­ate new neu­rons in response to phys­i­cal activ­ity and new expe­ri­ences. Sec­ond, they con­firmed the impor­tance of social con­nect­ed­ness to late-life cog­ni­tive, psy­cho­log­i­cal, and phys­i­cal health. The inte­gra­tion of these find­ings with our under­stand­ing of indi­vid­u­als’ devel­op­men­tal needs through­out life under­scores the impor­tance of the “social brain.” The pre­frontal cor­tex (PFC) is par­tic­u­larly inte­gral to nav­i­gat­ing com­plex social behav­iors and hier­ar­chies over the life course.

In this arti­cle, I will briefly artic­u­late how the above find­ings inform the design of a social health-promotion pro­gram, the Expe­ri­ence Corps, which lever­ages seniors’ accu­mu­lated expe­ri­ences and social knowl­edge while pro­mot­ing con­tin­ued social, men­tal, and phys­i­cal health into the third age, when a person’s life goals are increas­ingly directed to legacy build­ing. Expe­ri­ence Corps har­nesses the time and wis­dom of one the world’s largest nat­ural grow­ing resources—aging adults—to pro­mote aca­d­e­mic achieve­ment and lit­er­acy in our devel­op­ing nat­ural resources—children—during a crit­i­cal period in child devel­op­ment. In so doing, older vol­un­teers instill a readi­ness to learn that may alter the child’s tra­jec­tory for edu­ca­tional and occu­pa­tional attain­ment, as well as life­long health. At the same time, pre­lim­i­nary evi­dence sug­gests that the senior vol­un­teers expe­ri­ence mea­sur­able improve­ments in their cog­ni­tive and brain health.

The Devel­op­ing Pre­frontal Cortex

The pre­frontal cor­tex is the brain’s plan­ning, or exec­u­tive, cen­ter. It inte­grates past and present infor­ma­tion to pre­dict the future and to select the best course of action. Exec­u­tive processes gen­er­ally involve the ini­ti­a­tion, plan­ning, coor­di­na­tion, and sequenc­ing of actions toward a goal. While we take these skills for granted, the brain requires con­sid­er­able resources to nav­i­gate unpre­dictable envi­ron­ments and to inte­grate the mul­ti­ple streams of infor­ma­tion that each of us cal­cu­lates hun­dreds of times per day. We often must flex­i­bly and quickly update plans and pri­or­i­ties and inhibit dis­tract­ing or irrel­e­vant infor­ma­tion in the envi­ron­ment and in mem­ory that may direct atten­tion away from a goal.

The PFC is evo­lu­tion­ar­ily the newest and largest region of the brain, and its growth over the mil­len­nia cor­re­sponds to the increas­ing impor­tance of social behav­ior to human sur­vival. Over time, col­lab­o­ra­tion and nego­ti­a­tion became at least as impor­tant to our sur­vival as agility. PFC mat­u­ra­tion is not com­plete until one’s early 20s,1 pre­sum­ably because the abil­ity to inte­grate mul­ti­ple streams of infor­ma­tion requires the mat­u­ra­tion of phys­i­cal, lin­guis­tic, and emo­tional sen­sory networks.2 The PFC’s extended devel­op­men­tal win­dow involves mat­u­ra­tion of net­works that con­trol atten­tion steadily from child­hood to adult­hood, allow­ing us to fil­ter mul­ti­ple streams of infor­ma­tion more efficiently.3, 4 For evi­dence, we have only to look at the deci­sions that ado­les­cents make; teens are often enam­ored with liv­ing in the moment and con­sid­er­ing the con­se­quences later. With age and expe­ri­ence, these pri­or­i­ties reverse and thoughts of con­se­quences pre­vail over the moment.

Dur­ing the PFC’s devel­op­men­tal win­dow, the brain may be par­tic­u­larly vul­ner­a­ble to insult.5–8 Early-life brain imag­ing and cog­ni­tive test­ing stud­ies show that lower socioe­co­nomic sta­tus (SES) in chil­dren, as mea­sured by fam­ily income, is asso­ci­ated with devel­op­men­tal lags in lan­guage and exec­u­tive func­tion and their asso­ci­ated brain struc­tures, like the PFC. We do not yet know if these mat­u­ra­tional lags make the brain more vul­ner­a­ble to the effects of addi­tional insults that accu­mu­late with age, nor do we know how mod­i­fi­able or reversible these imprints are in a fully devel­oped adult brain.

In addi­tion, we do not yet know whether socioe­co­nomic depri­va­tion in early life leaves a last­ing imprint on the devel­op­ing brain. We have estab­lished that birth to age two is a crit­i­cal period of rapid brain growth and devel­op­ment, and head growth is 75 per­cent com­plete by age two.9 From age two to seven, lan­guage typ­i­cally devel­ops rapidly through spo­ken and then writ­ten expres­sion. As such, there are crit­i­cal win­dows of brain and lan­guage devel­op­ment that, when nur­tured among chil­dren of all socioe­co­nomic back­grounds, may lead to long-lasting effects on school suc­cess, occu­pa­tional oppor­tu­ni­ties, and cog­ni­tive and psy­cho­log­i­cal health through­out life, thus reduc­ing eco­nom­i­cally related health disparities.

The late-developing PFC appears to be more vul­ner­a­ble than other brain regions. With increas­ing age come increas­ing dif­fi­cul­ties in exec­u­tive con­trol. Through lon­gi­tu­di­nal obser­va­tion, we have found that com­po­nents of exec­u­tive func­tion decline ear­lier than mem­ory in older community-dwelling adults, and inter­ven­tion tar­get­ing these com­po­nents may delay and mit­i­gate mem­ory decline that leads to dementia.10 Con­sis­tent with this find­ing, stud­ies of the aging human brain show that loss of brain vol­ume is greater in the PFC than in pos­te­rior areas of the cortex.11–15

Healthy aging is not defined sim­ply as the avoid­ance and man­age­ment of chronic dis­eases. Healthy behav­iors, includ­ing phys­i­cal activ­ity, social sup­ports and engage­ment, and cog­ni­tive activ­ity, remain impor­tant to over­all health and pre­ven­tion of cog­ni­tive decline and dis­abil­ity as peo­ple age—even into the old­est ages.16, 17 How­ever, it has proven dif­fi­cult to moti­vate older adults to par­tic­i­pate in health-behavior change pro­grams, espe­cially for sus­tained peri­ods of time.18 Accord­ing to devel­op­men­tal psy­chol­o­gist Erik Erik­son, the third act of life rep­re­sents an oppor­tu­nity to use a life­time of accu­mu­lated knowledge—the kind of knowl­edge that is not eas­ily mem­o­rized from books, class­room lec­tures, or online searches—to find purpose.19 This type of knowl­edge comes from decades of inter­pret­ing and under­stand­ing unpre­dictable social behav­iors in order to pre­dict and shape future rewards—not one’s own future, but that of suc­ceed­ing gen­er­a­tions through the legacy of trans­fer. I will out­line here a ratio­nale for valu­ing these abil­i­ties and, in so doing, iden­tify a vehi­cle by which to main­tain cog­ni­tive, phys­i­cal, and social activ­ity through­out life to buffer the effects of age and dis­ease on the mind and body.

To con­tinue read­ing this arti­cle by Michelle C. Carl­son, Ph.D., pub­lished in Cere­brum, please click Here.

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Categories: Cognitive Neuroscience, Education & Lifelong Learning, Health & Wellness

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