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.”

About SharpBrains

SHARPBRAINS is an independent think-tank and consulting firm providing services at the frontier of applied neuroscience, health, leadership and innovation.
SHARPBRAINS es un think-tank y consultoría independiente proporcionando servicios para la neurociencia aplicada, salud, liderazgo e innovación.

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