Sharp Brains: Brain Fitness and Cognitive Health News

Neuroplasticity, Brain Fitness and Cognitive Health News

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To boost brainpower, ignore “smart drugs” and focus on experiences that harness neuroplasticity the right way

brain_scans

Tra­di­tion­al sci­en­tif­ic ideas cast the human brain as a fixed and essen­tial­ly lim­it­ed sys­tem that only degrades with age. This view saw the brain as a rigid machine in many ways, pret­ty much set after child­hood. By con­trast, we have now come to appre­ci­ate that the human brain is actu­al­ly a high­ly dynam­ic and con­stant­ly reor­ga­niz­ing sys­tem, capa­ble of being shaped and reshaped across the entire lifes­pan. It is believed that every expe­ri­ence alters the brain’s orga­ni­za­tion at some lev­el. The cen­tral con­cept in this new approach is neu­ro­plas­tic­i­ty, the brain’s life­long capac­i­ty to change and rewire itself in response to the stim­u­la­tion of learn­ing and expe­ri­ence. This includes both the life­long abil­i­ty to cre­ate new neu­rons – neu­ro­ge­n­e­sis – and to cre­ate new con­nec­tions between neu­rons – synap­to­ge­n­e­sis.

In a young brain, neu­ro­plas­tic­i­ty, includ­ing neu­ro­ge­n­e­sis and synap­to­ge­n­e­sis, allows for fast learn­ing, as well as for poten­tial­ly faster repair. As we age, the rate of neu­ro­plas­tic­i­ty declines, but does not come to a halt.

Life­long neu­ro­plas­tic­i­ty has major con­se­quences. At a basic lev­el, it means that our lifestyles and actions play a mean­ing­ful role in how our brains phys­i­cal­ly change through­out life. More specif­i­cal­ly, neu­ro­plas­tic­i­ty gives us the pow­er to resist the effects of decline or dis­ease by sup­port­ing our abil­i­ty to accu­mu­late knowl­edge and expe­ri­ences, i.e., to learn. Learn­ing helps to increase the so-called brain reserve and strength­en the brain against age-relat­ed decline and poten­tial demen­tia pathol­o­gy by increas­ing the con­nec­tions between neu­rons, increas­ing cel­lu­lar metab­o­lism, and increas­ing the pro­duc­tion of nerve growth fac­tor, a sub­stance pro­duced by the body to help main­tain and repair neu­rons.

Fur­ther­more, neu­ro­plas­tic­i­ty not only enables us to pre­vent future cog­ni­tive decline but also pro­vides a basis for a more opti­mistic out­look when it comes to our abil­i­ty to address exist­ing deficits, such as learn­ing dif­fi­cul­ties and recov­ery after trau­mat­ic brain injury or stroke. And final­ly, beyond pre­vent­ing decline and over­com­ing deficits, neu­ro­plas­tic­i­ty is at the core of the abil­i­ty to active­ly improve our brains through brain train­ing. By prac­tic­ing a skill, one can repeat­ed­ly stim­u­late the same area of the brain, which strength­ens exist­ing neur­al con­nec­tions and cre­ates new ones. Over time, the brain can become more effi­cient, requir­ing less effort to do the same job.

Brain imag­ing pro­vides exam­ples of neu­ro­plas­tic­i­ty

A key con­trib­u­tor to our grow­ing under­stand­ing of large-scale neu­ro­plas­tic­i­ty was the devel­op­ment of high-lev­el brain imag­ing tech­nolo­gies. By allow­ing sci­en­tists to pro­duce images of the brain that show its struc­ture, as well as where activ­i­ty spikes as it is engages in var­i­ous cog­ni­tive activ­i­ties, these neu­roimag­ing meth­ods have rev­o­lu­tion­ized neu­ro­science in the same way that the tele­scope rev­o­lu­tion­ized astron­o­my.

Evi­dence of neu­ro­plas­tic­i­ty gleaned from brain imag­ing has come most­ly from the brains of indi­vid­u­als who became experts in a par­tic­u­lar skill. Why? Because, as you might  have guessed, changes asso­ci­at­ed with learn­ing occur mas­sive­ly when we become expert in a spe­cif­ic func­tion or domain.

For exam­ple, sev­er­al fas­ci­nat­ing stud­ies shows that Lon­don taxi dri­vers have a larg­er hip­pocam­pus than Lon­don bus dri­vers. This is explained by the fact that the hip­pocam­pus is impor­tant for form­ing and access­ing com­plex mem­o­ries, includ­ing the spa­tial mem­o­ries nec­es­sary for effi­cient nav­i­ga­tion. Taxi dri­vers have to nav­i­gate around Lon­don where­as bus dri­vers fol­low a lim­it­ed set of routes. Thus, the hip­pocam­pus of a taxi dri­ver is par­tic­u­lar­ly stim­u­lat­ed and changes over time as a result.

Plas­tic­i­ty can also be observed in the brains of bilin­guals. It looks like learn­ing a sec­ond lan­guage is direct­ly asso­ci­at­ed with struc­tur­al changes in the brain: a region called the left infe­ri­or pari­etal cor­tex is larg­er in bilin­gual brains than in mono­lin­gual brains. Plas­tic changes have also been found to occur in musi­cians’ brains (com­pared to non-musi­cians), with areas involved in play­ing music (motor regions, ante­ri­or supe­ri­or pari­etal areas, and infe­ri­or tem­po­ral areas) show­ing increased vol­ume.

These changes do not require a life­time to occur; a few years or even months can be enough. For instance, researchers imaged the brains of Ger­man med­ical stu­dents three months before their med­ical exam, and again right after the exam, and then com­pared the brains of these stu­dents to the brains of stu­dents who were not study­ing for the exam at this time. The results: Med­ical stu­dents’ brains showed changes in regions of the pari­etal cor­tex as well as in the pos­te­ri­or hip­pocam­pus. As you can prob­a­bly guess, these regions are known to be involved in mem­o­ry and learn­ing.

Don’t count on mir­a­cles

The large-scale changes observed in these stud­ies were the result of seri­ous effort over time, be it learn­ing the streets of Lon­don or study­ing for a med­ical exam. It would be nice, of course, if we could all just take a pill to quick­ly and pain­less­ly increase brain fit­ness: to sud­den­ly become more atten­tive, nev­er for­get a name, and per­form all the men­tal math we want. How­ev­er, despite large invest­ments, evi­dence that “smart” drugs actu­al­ly work is scarce at the present. The recent exten­sive NIH meta-analy­sis found no evi­dence that any of the med­ica­tions tracked (name­ly statins, anti­hy­per­ten­sive med­ica­tions, cholinesterase inhibitors, or estro­gen) were suc­cess­ful at improv­ing or main­tain­ing cog­ni­tive func­tion­ing over time. Some drugs have pro­duced pos­i­tive effects for peo­ple who have neu­ro­log­i­cal dis­or­ders such as Alzheimer’s dis­ease, Parkinson’s dis­ease, or Atten­tion Deficit Dis­or­der – when patients take these drugs, their symp­toms are usu­al­ly less­ened. How­ev­er, no sol­id sci­en­tif­ic evi­dence has shown so far that these drugs are reli­ably ben­e­fi­cial or safe for peo­ple with nor­mal func­tion­ing. Even in the sup­posed sce­nario that a smart drug that can “dou­ble brain­pow­er” with no side effects is dis­cov­ered, it would be mis­guid­ed to believe that the drug alone would be enough. If things worked that way, why do steroid-tak­ing ath­letes still have to pay atten­tion to their phys­i­cal exer­cise reg­i­mens?SharpBrainsGuide_3D_compressed

What is sup­port­ed by ample evi­dence is the brain’s capac­i­ty to be flex­i­ble and be mold­ed through expe­ri­ence. The ques­tion then becomes: “What activ­i­ties or behav­iors can pro­vide the right kind of expe­ri­ence to help opti­mize my brain?”

–This is an adapt­ed excerpt from the book “The Sharp­Brains Guide to Brain Fit­ness: How to Opti­mize Brain Health and Per­for­mance at Any Age” (April 2013; 284 pages), fea­tured by Kirkus Reviews as “A stim­u­lat­ing, chal­leng­ing resource, full of sol­id infor­ma­tion and prac­ti­cal tips for improv­ing brain health.”

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As seen in The New York Times, The Wall Street Journal, BBC News, CNN, Reuters,  SharpBrains is an independent market research firm tracking how brain science can improve our health and our lives.

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