(Editor’s Note: In 1990, Con­gress des­ig­nated the 1990s the “Decade of the Brain.” Pres­i­dent George H. W. Bush pro­claimed, “A new era of dis­cov­ery is dawn­ing in brain research.” Dur­ing the ensu­ing decade, sci­en­tists greatly advanced our under­stand­ing of the brain. The edi­tors of Cere­brum asked the direc­tors of seven brain-related insti­tutes at the National Insti­tutes of Health (NIH) to iden­tify the biggest advances, great­est dis­ap­point­ments, and missed oppor­tu­ni­ties of brain research in the past decade—the decade after the “Decade of the Brain.” They also asked them what looks most promis­ing for the com­ing decade, the 2010s. Experts focused on research that might change how doc­tors diag­nose and treat human brain disorders.)

Neu­ro­science is at a his­toric turn­ing point. Today, a full decade after the “Decade of the Brain,” a con­tin­u­ous stream of advances is shat­ter­ing long-held notions about how the human brain works and what hap­pens when it doesn’t. These advances are also reshap­ing the land­scapes of other fields, from psy­chol­ogy to eco­nom­ics, edu­ca­tion and the law.

Until the Decade of the Brain, sci­en­tists believed that, once devel­op­ment was over, the adult brain under­went very few changes. This per­cep­tion con­tributed to polar­iz­ing per­spec­tives on whether genet­ics or envi­ron­ment deter­mines a person’s tem­pera­ment and per­son­al­ity, apti­tudes, and vul­ner­a­bil­ity to men­tal dis­or­ders. But dur­ing the past two decades, neu­ro­sci­en­tists have steadily built the case that the human brain, even when fully mature, is far more plastic—changing and malleable—than we orig­i­nally thought.1 It turns out that the brain (at all ages) is highly respon­sive to envi­ron­men­tal stim­uli and that con­nec­tions between neu­rons are dynamic and can rapidly change within min­utes of stimulation.

Neu­ro­plas­tic­ity is mod­u­lated in part by genetic fac­tors and in part by dynamic, epi­ge­netic changes that influ­ence the expres­sion of genes with­out chang­ing the DNA sequence. Epi­ge­netic processes are of par­tic­u­lar clin­i­cal inter­est because their exter­nal trig­gers (such as early parental care, diet, drug abuse and stress) can affect a person’s vul­ner­a­bil­ity to many dis­eases, includ­ing psy­chi­atric dis­or­ders. In addi­tion, in con­trast to genetic sequence dif­fer­ences, epi­ge­netic alter­ations are poten­tially reversible, and thus amenable to pub­lic health pol­icy interventions.

It also has become increas­ingly clear that the human brain is par­tic­u­larly sen­si­tive to social stim­uli, which likely has accel­er­ated the rate of human brain evo­lu­tion. Humans have evolved a com­plex neu­ronal cir­cuitry in large areas in the brain to process com­plex social infor­ma­tion (such as pre­dict­ing oth­ers’ reac­tions and emo­tions) and to respond appro­pri­ately. New research has revealed that social stim­uli (such as par­ent­ing style and early-life stress) can epi­ge­net­i­cally mod­ify the expres­sion of genes that influ­ence brain mor­phol­ogy and func­tion includ­ing the sen­si­tiv­ity of an indi­vid­ual to stress­ful stimuli.2 In the future, this knowl­edge will enable us to tai­lor per­son­al­ized pre­ven­tion inter­ven­tions that are based on infor­ma­tion on how genet­ics and epi­ge­net­ics affect brain func­tion and behav­ior. For exam­ple, a recent study showed that a pre­ven­tion inter­ven­tion based on improv­ing par­ent­ing style reduced the risk for sub­stance use dis­or­ders only in ado­les­cents with a par­tic­u­lar vari­ant of a gene that recy­cles the chem­i­cal sero­tonin back into the neu­rons, which is a vari­ant that results in greater sen­si­tiv­ity to social adversity.3

In the com­ing decade, insights about what under­lies neu­ro­plas­tic­ity, com­bined with tech­no­log­i­cal advances that allow us to “see” with greater pre­ci­sion the human brain in action, are bound to rev­o­lu­tion­ize the way we view learn­ing and the meth­ods we use to edu­cate young peo­ple. New research will also show us how to help peo­ple over­come or com­pen­sate for many of the deficits asso­ci­ated with drug abuse, addic­tion and other men­tal disorders.4

For exam­ple, sci­en­tists are using imag­ing tech­nolo­gies in neu­ro­feed­back pro­grams that train peo­ple to vol­un­tar­ily recal­i­brate their neural activ­ity in spe­cific areas of the brain, allow­ing them to gain unprece­dented con­trol over, for exam­ple, pain perception5 or emo­tional processing.6 Dur­ing drug addic­tion treat­ment, this approach could greatly reduce the risk of relapse by enabling a patient to con­trol the pow­er­ful crav­ings trig­gered by a host of cues (e.g., peo­ple, things, places) that have become tightly linked, in the brain of the user, to the drug experience.

Other promis­ing advances stem from ongo­ing research and devel­op­ment of direct com­mu­ni­ca­tion path­ways between a brain and exter­nal com­puter devices, the so called brain-computer inter­faces (BCI). In a recent study, one ver­sion of BCI appeared to help par­a­lyzed stroke vic­tims regain some move­ment control.7 In the next decade, forms of BCI might help peo­ple with a vari­ety of neu­ropsy­chi­atric con­di­tions that have proved resis­tant to tra­di­tional treat­ments. For exam­ple, early evi­dence sug­gests that BCI train­ing could ben­e­fit patients with epilepsy or attention-deficit/hyperactivity dis­or­der (ADHD) that is unre­spon­sive to drugs.8

As we build on these rapid advances in neu­ro­science research, we must keep a watch­ful eye on their vast social and polit­i­cal impli­ca­tions. For exam­ple, neu­rol­o­gists have started to uncover the mol­e­c­u­lar com­po­nents and neural cir­cuitry that under­lie the learn­ing process.9 We also are learn­ing how to use tran­scra­nial mag­netic stim­u­la­tion (TMS), a non­in­va­sive method to mod­u­late the activ­ity within a neural cir­cuit, more effectively.10 Should we use this knowl­edge to bet­ter edu­cate young peo­ple and teach new skills to seniors, or should we use these tools only to treat peo­ple with neu­ropsy­chi­atric dis­or­ders? As we begin to under­stand how par­ent­ing styles affect the devel­op­ment and func­tion of the brain, how far should we go to pro­tect chil­dren from the long-term and dele­te­ri­ous effects of bad parenting?

Recent progress in brain research and asso­ci­ated fields has been impres­sive, and we are sure to wit­ness fur­ther accel­er­a­tion in the pace of neu­ro­sci­en­tific dis­cov­ery in the next cou­ple of decades. Indeed, we are enter­ing a new era in which our tech­nolo­gies are begin­ning to affect our lives in pro­found ways. We are bound to recast our rela­tion­ship with our brains and, in the process, to redraw the bound­aries of human evolution.

(Note: ref­er­ences are avail­able below)

Nora D. Volkow, M.D., became direc­tor of the National Insti­tute on Drug Abuse (NIDA) in May 2003. Her work has been instru­men­tal in demon­strat­ing that drug addic­tion is a dis­ease of the human brain. As a research psy­chi­a­trist and sci­en­tist, Dr. Volkow pio­neered the use of brain imag­ing to inves­ti­gate the toxic effects of drugs and their addic­tive prop­er­ties. She also has made impor­tant con­tri­bu­tions to the neu­ro­bi­ol­ogy of obe­sity, ADHD, and the behav­ioral changes that occur with aging. Arti­cle is repub­lished with per­mis­sion from the Dana Foundation.

‘A Decade after The Decade of the Brain’ series, at Cere­brum

Thurs­day, Feb. 18: Nora D. Volkow, M.D., National Insti­tute on Drug Abuse

Fri­day, Feb. 19: Thomas R. Insel, M.D., National Insti­tute of Men­tal Health

Mon­day, Feb. 22: Story Lan­dis, Ph.D., National Insti­tute of Neu­ro­log­i­cal Dis­or­ders and Stroke

Tues­day, Feb. 23: Ken­neth R. War­ren, Ph.D., National Insti­tute on Alco­hol Abuse and Alcoholism

Wednes­day, Feb. 24: Paul A. Siev­ing, M.D., Ph.D., National Eye Institute

Thurs­day, Feb. 25: James F. Bat­tey Jr., M.D., Ph.D., National Insti­tute on Deaf­ness and Other Com­mu­ni­ca­tion Disorders

Fri­day, Feb. 26: Richard J. Hodes, M.D., National Insti­tute on Aging

Ref­er­ences

1.  A. Holt­maat and K. Svo­boda, “Experience-Dependent Struc­tural Synap­tic Plas­tic­ity in the Mam­malian Brain,” Nature Reviews Neu­ro­science 10, no. 9 (2009): 647–658; M. Butz, F. Wor­got­ter, and A. van Ooyen, “Activity-Dependent Struc­tural Plas­tic­ity,” Brain Research Reviews 60, no. 2 (2009): 287–305.

2. I. C. Weaver, N. Cer­voni, F. A. Cham­pagne, A. C. D’Alessio, S. Sharma, J. R. Seckl, S. Dymov, M. Szyf, and M. J. Meaney, “Epi­ge­netic Pro­gram­ming by Mater­nal Behav­ior,” Nature Neu­ro­science 7, no. 8 (2004): 847–854.

3. G. H. Brody, S. R. Beach, R. A. Philib­ert, Y. F. Chen, M. K. Lei, V. M. Murry, and A. C. Brown, “Par­ent­ing Mod­er­ates a Genetic Vul­ner­a­bil­ity Fac­tor in Lon­gi­tu­di­nal Increases in Youths’ Sub­stance Use,” Jour­nal of Con­sult­ing and Clin­i­cal Psy­chol­ogy 77, no. 1 (2009): 1–11.

4. N. D. Volkow, L. Chang, G. J. Wang, J. S. Fowler, D. Franceschi, M. Sedler, S. J. Gat­ley, E. Miller, R. Hitze­mann, Y. S. Ding, and J. Logan, “Loss of Dopamine Trans­porters in Metham­phet­a­mine Abusers Recov­ers with Pro­tracted Absti­nence,” Jour­nal of Neu­ro­science 21, no. 23 (2001): 9414–9418.

5. R. C. deCharms, F. Maeda, G. H. Glover, D. Lud­low, J. M. Pauly, D. Soneji, J. D. Gabrieli, and S. C. Mackey, “Con­trol over Brain Acti­va­tion and Pain Learned by Using Real-time Func­tional MRI,” Pro­ceed­ings of the National Acad­emy of Sci­ences USA 102, no. 51 (2005): 18626–18631; S. J. John­ston, S. G. Boehm, D. Healy, R. Goebel, and D. E. Lin­den, “Neu­ro­feed­back: A Promis­ing Tool for the Self-regulation of Emo­tion Net­works,” Neu­roim­age 49, no. 1 (2009): 1066–1072.

6. S. John­ston, S. Boehm, D. Healy, R. Goebel, and D. Lin­den, “Neu­ro­feed­back: A promis­ing tool for the self-regulation of emo­tion net­works,” Neu­roim­age 49 (2009):1066–1072.

7. E. Buch, C. Weber, L. G. Cohen, C. Braun, M. A. Dimyan, T. Ard, J. Mellinger, A. Caria, S. Soekadar, A. Fourkas, and N. Bir­baumer, “Think to Move: a Neu­ro­mag­netic Brain-Computer Inter­face (BCI) Sys­tem for Chronic Stroke,” Stroke 39, no. 3 (2008): 910–917.

8. N. Bir­baumer, A. Ramos Mur­guial­day, C. Weber, and P. Mon­toya, “Neu­ro­feed­back and Brain-Computer Inter­face Clin­i­cal Appli­ca­tions,” Inter­na­tional Review of Neu­ro­bi­ol­ogy 86 (2009): 107–117.

9. C. A. Miller, S. L. Camp­bell, and J. D. Sweatt, “DNA Methy­la­tion and His­tone Acety­la­tion Work in Con­cert to Reg­u­late Mem­ory For­ma­tion and Synap­tic Plas­tic­ity,” Neu­ro­bi­ol­ogy of Learn­ing and Mem­ory 89, no. 4 (2008): 599–603.

10. C. A. Dock­ery, R. Hueckel-Weng, N. Bir­baumer, and C. Plew­nia, “Enhance­ment of Plan­ning Abil­ity by Tran­scra­nial Direct Cur­rent Stim­u­la­tion,” Jour­nal of Neu­ro­science 29, no. 22 (2009): 7271–7277.

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