Cognitive Ability: Brain Games or Drugs?

A recent sci­en­tif­ic study is being wel­comed as a land­mark that shows how flu­id intel­li­gence can be improved through train­ing. I inter­viewed one of the researchers recent­ly (Can Intel­li­gence Be Trained? Mar­tin Buschkuehl shows how), and con­trib­u­tor Dr. Pas­cale Mich­e­lon adds her own take with the great arti­cle that fol­lows. Enjoy!

Ref­er­ence: Jaeg­gi, S. M., Buschkuehl, M., Jonides, J., & Per­rig, W. J. (2008). Improv­ing Flu­id Intel­li­gence With Train­ing on Work­ing Mem­o­ry. Pro­ceed­ings of the Nation­al Acad­e­my of Sci­ences of the Unit­ed States of Amer­i­ca, 105(19), 6829–6833

——————

What is intelligence? 

Intel­li­gence is a con­cept dif­fi­cult to define as it seems to cov­er many dif­fer­ent types of abilities.

One def­i­n­i­tion dis­so­ci­ates between crys­tal­lized intel­li­gence or abil­i­ties and flu­id intel­li­gence. Crys­tal­lized intel­li­gence refers to the knowl­edge acquired through­out life such as vocab­u­lary. Flu­id intel­li­gence is the abil­i­ty that allows us to adapt to new sit­u­a­tions or problems.

Age does not affect crys­tal­lized and flu­id intel­li­gence the same way. In 2004, Schaie and col­leagues pub­lished the results of the Seat­tle study. In this study, the researchers col­lect­ed infor­ma­tion on par­tic­i­pants over 7 test­ing cycles (from 1956 to 1998). The results showed that flu­id abil­i­ties tend to decline ear­li­er than crys­tal­lized abil­i­ties. In 2004, Lov­den and col­leagues pub­lished the results of the Berlin Aging Study, which includ­ed 516 par­tic­i­pants assessed 5 times over a peri­od of 13 years. The results show a steady decline in flu­id abil­i­ties. In con­trast, crys­tal­lized abil­i­ties were quite sta­ble over time and even tend­ed to increase.

Can we train intelligence?

There a lot of drugs that sup­pos­ed­ly increase intel­li­gence and makes one smarter. How­ev­er there is no sci­en­tif­ic evi­dence show­ing that these drugs have any mea­sur­able effects on performance.

In terms of train­ing, sev­er­al stud­ies have shown that prac­tic­ing spe­cif­ic tasks will indeed increase per­for­mance in these tasks. Prob­lem­at­i­cal­ly, trans­fer of the train­ing ben­e­fits to a dif­fer­ent task (not prac­ticed) has been rarely shown.

How­ev­er, in a very recent 2008 study pub­lished in the Pro­ceed­ings of the Nation­al Acad­e­my of Sci­ences, Jaeg­gi and her col­leagues were able to shown that flu­id intel­li­gence could be improved by train­ing on work­ing mem­o­ry. In oth­er words they showed that train­ing young adults using a work­ing mem­o­ry task induced per­for­mance ben­e­fits that trans­ferred to flu­id intel­li­gence tasks.

Jaeg­gi and her col­leagues trained four groups of young adults using a com­plex work­ing mem­o­ry task, called a dual n‑back task (Work­ing mem­o­ry is the abil­i­ty to hold infor­ma­tion for a short while in mem­o­ry and use that infor­ma­tion to solve a prob­lem). In the task par­tic­i­pants had to hold in mem­o­ry both the loca­tions of squares shown on a com­put­er screen and con­so­nants heard through head­phones. A response was required when­ev­er one of the pre­sent­ed stim­uli matched the one pre­sent­ed n posi­tions back in the sequence. Quite com­plex as you can see!

Par­tic­i­pants (approx­i­mate­ly 16 per group) were trained for 25 min­utes per day for 8 days, 12 days, 17 days or 19 days. Flu­id intel­li­gence was assessed before the train­ing and after the train­ing using stan­dard­ized tests (con­sist­ing in visu­al anal­o­gy problems).

Con­trol groups, who did not receive any train­ing, were also test­ed for flu­id intel­li­gence at the same inter­vals as the trained groups.

Results showed that the trained groups did bet­ter in the flu­id intel­li­gence tasks after the train­ing than before the train­ing. Impor­tant­ly, this gain was greater than the gain seen in the con­trol groups.

Why would the con­trol groups also improve when they did not get any train­ing? They mere­ly had some prac­tice tak­ing the intel­li­gence test giv­en that the test was admin­is­tered twice (this is why it is cru­cial to show that the trained groups shows more ben­e­fit than the con­trol groups).

This result is one of the rare ones show­ing that trans­fer of train­ing gains exists. Here the ben­e­fits from being trained on a com­plex work­ing mem­o­ry task trans­ferred to a test of flu­id intel­li­gence. This is prob­a­bly pos­si­ble because work­ing mem­o­ry and flu­id intel­li­gence are relat­ed in sev­er­al ways. First, both require to use atten­tion­al and con­trol process­es. Sec­ond, they both rely on sim­i­lar neur­al net­works: lat­er­al pre­frontal and pari­etal cortices.

Note that the effect of the train­ing on the intel­li­gence task became sig­nif­i­cant only after 17 days of train­ing and not before. How­ev­er, giv­en the small num­ber of par­tic­i­pants in each group, one would need more research includ­ing more par­tic­i­pants to know for sure how many days of train­ing are need­ed to get a ben­e­fit. It would also be inter­est­ing to learn how long these effects last.

In con­clu­sion it looks like one can use train­ing to boost one’s flu­id intelligence.

Trans­fer of train­ing effects are real­ly a must, espe­cial­ly in this domain, because new sit­u­a­tions come up all the time and you can­not train your­self on all pos­si­ble situations.

The same argu­ment applies to com­put­er­ized brain games: play­ing the same game over and over will increase your per­for­mance in that game. But what you real­ly want to see is a trans­fer of the ben­e­fits induced by play­ing that game to oth­er every­day tasks. More research is need­ed then!

— This arti­cle was writ­ten by Pas­cale Mich­e­lon, Ph. D., for SharpBrains.com. Copy­right 2008. Dr. Mich­e­lon has a Ph.D. in Cog­ni­tive Psy­chol­o­gy and has worked as a Research Sci­en­tist at Wash­ing­ton Uni­ver­si­ty in Saint Louis, in the Psy­chol­o­gy Depart­ment. She con­duct­ed sev­er­al research projects to under­stand how the brain makes use of visu­al infor­ma­tion and mem­o­rizes facts. She is now an Adjunct Fac­ul­ty at Wash­ing­ton Uni­ver­si­ty, and teach­es Mem­o­ry Work­shops in numer­ous retire­ment com­mu­ni­ties in the St Louis area.