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Memory Training Reduces Brain Atrophy

Numer­ous stud­ies show ben­e­fits of cog­ni­tive train­ing in old­er adults, despite a recent study ques­tion­ing their valid­i­ty. The debate on the effects of spe­cif­ic cog­ni­tive inter­ven­tions is not set­tled.

A find­ing that researchers do seem to agree on is that aging is accom­pa­nied by brain and cog­ni­tive decline. These reduc­tions seem to be mod­i­fi­able through cog­ni­tive and phys­i­cal exer­cise. In this vein, our lab recent­ly demon­strat­ed that old­er adults involved in an 8-week mem­o­ry train­ing pro­gram show less brain atro­phy. This gives some hope for old­er adults won­der­ing whether their train­ing efforts are real­ly worth­while.

A major research inter­est in our lab is how brain struc­ture and mem­o­ry change across the human life-span. We have recent­ly been able to mea­sure region­al changes in the brain with­in the same old­er adults over time. In a recent study, my super­vi­sor, Anders Fjell and col­leagues found that nor­mal aging Amer­i­cans (about 60 years old) show region­al brain atro­phy (shrink­age) of about — 0.5 – 1.0 % after only one year.

The rea­son why the brain atro­phies (shrinks in size) with age is not com­plete­ly under­stood. An old myth about aging is that we lose neu­rons as we age. This does not seem to hold true for healthy old­er adults. Instead, researchers cur­rent­ly believe that the atro­phy is more like­ly to be dri­ven by 1) nerve cells shrink­ing and 2) loss of con­nec­tions between nerve cells

Not only brain size, but also cog­ni­tive per­for­mance declines as we age. Abil­i­ties like pro­cess­ing speed and long-term mem­o­ry declines steadi­ly. How­ev­er, the pace of aging varies great­ly among old­er indi­vid­u­als. Thus, a cen­tral pur­suit in con­tem­po­rary neu­ro­science is to under­cov­er mod­i­fiers of the aging process.

Var­i­ous fac­tors are found to be asso­ci­at­ed with age-relat­ed dif­fer­ences in brain struc­ture and cog­ni­tion. Your genet­ic make­up seems to be impor­tant. Also what socioe­co­nom­ic back­ground and edu­ca­tion­al lev­el you have plays a role.

Late­ly and thor­ough­ly reviewed in the Sharp­brains blog ear­li­er, lifestyle and behav­ior seem to have a sig­nif­i­cant impact. One exam­ple is nutri­tion. In fact, David Smith and col­leagues in Oxford showed ear­li­er this fall that old­er adults with mild cog­ni­tive impair­ment have less brain atro­phy if they take a vit­a­min-B sup­ple­ment reg­u­lar­ly.

Oth­er lifestyle fac­tors con­tribut­ing to indi­vid­ual age-dif­fer­ences in both brain and cog­ni­tive func­tion are phys­i­cal and men­tal exer­cise or brain train­ing. The basis for how these influ­ence the aging process is based on the con­cept of brain plas­tic­i­ty. Brain plas­tic­i­ty is a mul­ti­fac­eted con­cept, but can be described as your brain’s abil­i­ty to change struc­tural­ly and func­tion­al­ly at any age.

In our lab we were fas­ci­nat­ed by this abil­i­ty and asked the fol­low­ing ques­tion: Could mem­o­ry train­ing impact the brain atro­phy that takes place in the aging brain? With this in mind, my research group set out to inves­ti­gate the effects of a mem­o­ry train­ing pro­gram for healthy mid­dle-aged and old­er adults (mean age = 60 years).

Through a news­pa­per add, we recruit­ed more than 40 par­tic­i­pants and divid­ed them ran­dom­ly into a mem­o­ry train­ing and con­trol group. The mem­o­ry train­ers par­tic­i­pat­ed in an 8-week pro­gram where they learned a visu­al mnemon­ic tech­nique known as the Method of loci. Using this tech­nique the par­tic­i­pants had to learn and recall new ver­bal infor­ma­tion almost every­day, like the names of Amer­i­can pres­i­dents, Roman emper­ors, mem­bers of par­lia­ment, and the order of coun­tries in South-Amer­i­ca.

After 8-weeks of train­ing, we found that:

a) the mem­o­ry train­ers improved sig­nif­i­cant­ly in their abil­i­ty to remem­ber ver­bal infor­ma­tion in a par­tic­u­lar sequence (for instance the name of the 1st or 10th Amer­i­can pres­i­dent). How­ev­er, they did not improve more on oth­er domains of mem­o­ry func­tion than the con­trol group, which is in-line with oth­er stud­ies.

b) the thick­ness of the cere­bral cor­tex increased in sev­er­al regions of the brain among those who had trained their mem­o­ry func­tion. Also, par­tic­i­pants who had improved the most on the spe­cif­ic mem­o­ry test where the ones with the most increase in cor­ti­cal (brain) thick­ness.

The four regions of the brains in which mem­o­ry train­ing increased cor­ti­cal thick­ness are illus­trat­ed below. Two effects were locat­ed in the frontal lobes (lat­er­al orbitofrontal cor­tex), and one in the fusiform region of the right tem­po­ral lobe.

Fig­ure 1. The fig­ure show the strength of the effects mapped on a tem­plate brain. Top row is the right hemi­sphere in lat­er­al (from out­side), ven­tral (from under) and medi­al (from inside) views.

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The changes in cor­ti­cal thick­ness in the con­trol and train­ing groups are shown in the sec­ond fig­ure below. You can see that the con­trol group decreased slight­ly, where­as the mem­o­ry train­ers increased. Also note that the changes are small (less than 0.05 mm in most areas).

Fig­ure 2. Bar plots of the group-changes in cor­ti­cal thick­ness. The green bars are the con­trol group, the blue col­ors are the train­ing group. Lighter col­ors are the aver­age thick­ness at fol­low-up.

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What do these find­ings tell us? It seems as mid­dle-aged and old­er adults who train their mem­o­ry vig­or­ous­ly in a 2-month peri­od have dif­fer­ent, more pos­i­tive changes in brain struc­ture, com­pared with those who do not. The ones who had bet­ter mem­o­ry improve­ments also had more pos­i­tive changes in the brain. The effects on mem­o­ry per­for­mance were pos­i­tive, but the trans­fer effect was seen on brain struc­ture only. We did not look at the effects beyond the 2-months, and we are wait­ing to see whether cog­ni­tive exer­cise indeed alters the way our brains age in the long-term. Since our study was pub­lished, oth­er very recent stud­ies have shown that cog­ni­tive exer­cise in the elder­ly can also mod­i­fy the blood flow to, and the under­ly­ing nerve fibers (white mat­ter) of the frontal lobes.

Mem­o­ry train­ing improves spe­cif­ic mem­o­ry func­tions, but also seems to make pos­i­tive changes in the aging brain such as less atro­phy and even increased cor­ti­cal thick­ness. These results strength­en the con­clu­sions about the val­ue of men­tal exer­cise for old­er adults.

— Andreas Engvig was an intern at Sharp­brains a cou­ple of years ago. He is now a MD-PhD can­di­date in the Cen­ter for the Study of Human Cog­ni­tion at the Uni­ver­si­ty of Oslo, Nor­way. He is cur­rent­ly pur­su­ing his PhD inves­ti­gat­ing the effects of mem­o­ry train­ing on aging brain struc­tures. His first pub­li­ca­tion recent­ly achieved 8th place in Neuroimage’s “Top 25 Hottest Arti­cles” list.

Ref­er­ences

  • Engvig, A., Fjell, A.M., West­lye, L.T., Mober­get, T., Sund­seth, O., Larsen, V.A., Wal­hovd, K.B., 2010. Effects of mem­o­ry train­ing on cor­ti­cal thick­ness in the elder­ly. Neu­roIm­age 52, 1667–1676.
  • Engvig, A., Fjell, A.M., West­lye, L.T., Mober­get, T., Sund­seth, O., Larsen, V.A., Wal­hovd, K.B., sub­mit­ted man­u­script. Mem­o­ry train­ing impacts short-term changes in aging white mat­ter.
  • Esiri, M.M., 2007. Age­ing and the brain. J Pathol 211, 181–187.
  • Fjell, A.M., Wal­hovd, K.B., Fen­nema-Notes­tine, C., McEvoy, L.K., Hagler, D.J., Hol­land, D., Brew­er, J.B., Dale, A.M., 2009. One-year brain atro­phy evi­dent in healthy aging. J Neu­rosci 29, 15223–15231.
  • Kramer, A.F., Erick­son, K.I., 2007. Effects of phys­i­cal activ­i­ty on cog­ni­tion, well-being, and brain: human inter­ven­tions. Alzheimers Dement 3, S45-51.
  • Lam­precht, R., LeDoux, J., 2004. Struc­tur­al plas­tic­i­ty and mem­o­ry. Nat Rev Neu­rosci 5, 45–54.
  • Lov­den, M., Bodammer, N.C., Kuhn, S., Kauf­mann, J., Schutze, H., Tem­pel­mann, C., Heinze, H.J., Duzel, E., Schmiedek, F., Lin­den­berg­er, U., 2010. Expe­ri­ence-depen­dent plas­tic­i­ty of white-mat­ter microstruc­ture extends into old age. Neu­ropsy­cholo­gia 48, 3878–3883.
  • Mozolic, J.L., Hayasa­ka, S., Lau­ri­en­ti, P.J., 2010. A cog­ni­tive train­ing inter­ven­tion increas­es rest­ing cere­bral blood flow in healthy old­er adults. Front Hum Neu­rosci 4, 16.
  • Park, D.C., Reuter-Lorenz, P., 2009. The adap­tive brain: aging and neu­rocog­ni­tive scaf­fold­ing. Annu Rev Psy­chol 60, 173–196.
  • Reid, L., MacLul­lich, A., 2006. Sub­jec­tive Mem­o­ry Com­plaints and Cog­ni­tive Impair­ment in Old­er Peo­ple. Dement Geri­atr Cogn Dis­ord 22, 471–485.
  • Smith, A.D., Smith, S.M., de Jager, C.A., Whit­bread, P., John­ston, C., Agacin­s­ki, G., Oul­haj, A., Bradley, K.M., Jaco­by, R., Ref­sum, H., 2010. Homo­cys­teine-low­er­ing by B vit­a­mins slows the rate of accel­er­at­ed brain atro­phy in mild cog­ni­tive impair­ment: a ran­dom­ized con­trolled tri­al. PLoS ONE 5, e12244.
  • Valen­zuela, M., Sachdev, P., 2009. Can cog­ni­tive exer­cise pre­vent the onset of demen­tia? Sys­tem­at­ic review of ran­dom­ized clin­i­cal tri­als with lon­gi­tu­di­nal fol­low-up. Am J Geri­atr Psy­chi­a­try 17, 179–187.

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2 Responses

  1. My friend, THAT was an EXCELLENT piece! Very well laid out, and the EVIDENCE appears inar­guable. So that begs the ques­tion, who in their right mind would fail to see the ben­e­fits of strate­gic cog­ni­tive train­ing to improve their aging brain after see­ing this infor­ma­tion? I know I’ll ref­er­ence this when speak­ing to peo­ple I know who are enter­ing or liv­ing in their gold­en years. Trans­fer­abil­i­ty? It’s MEMORY for cry­ing out loud — that is very impor­tant! The way I fig­ure it, you throw in a lit­tle brain train­ing to help pro­cess­ing speed, tack on some brain train­ing to improve motor skills — all com­bined with mem­o­ry train­ing, med­i­ta­tion-relat­ed prac­tices, increased social inter­ac­tion, danc­ing, etc., and most peo­ple should be able enjoy a long term, high­er cog­ni­tive qual­i­ty of life.

  2. Andreas Engvig says:

    Thanks! Let me know if you need a pdf of the arti­cle. I like your idea of rec­om­mend­ing cross-modal brain train­ing to improve cog­ni­tive QoL after mid­dle-age.

    Cheers,

    -A

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