Brain Plasticity: How Learning Changes Your Brain

Plas makes it look easy. The New Yorker April 17 1999. Art Spiegelman cover.

by Dr. Pascale Michelon

You may have heard that the brain is plas­tic. As you know the brain is not made of plas­tic. Neu­ro­plas­tic­ity or brain plas­tic­ity refers to the brain’s abil­ity to change through­out life. The brain has the amaz­ing abil­ity to reor­ga­nize itself by form­ing new con­nec­tions between brain cells (neurons).

In addi­tion to genetic fac­tors, the envi­ron­ment in which a per­son lives, as well as the actions of that per­son, play a role in plasticity.

Neu­ro­plas­tic­ity occurs in the brain:

1– At the begin­ning of life: when the imma­ture brain orga­nizes itself.
2– In case of brain injury: to com­pen­sate for lost func­tions or max­i­mize remain­ing functions.
3– Through adult­hood: when­ever some­thing new is learned and memorized

Plas­tic­ity and brain injury

A sur­pris­ing con­se­quence of neu­ro­plas­tic­ity is that the brain activ­ity asso­ci­ated with a given func­tion can move to a dif­fer­ent loca­tion as a con­se­quence of nor­mal expe­ri­ence, brain dam­age or recovery.

In his book “The Brain That Changes Itself: Sto­ries of Per­sonal Tri­umph from the Fron­tiers of Brain Sci­ence, Nor­man Doidge describes numer­ous exam­ples of func­tional shifts.
In one of them, a sur­geon in his 50s suf­fers a stroke. His left arm is par­a­lyzed. Dur­ing his reha­bil­i­ta­tion, his good arm and hand are immo­bi­lized, and he is set to clean­ing tables. The task is at first impos­si­ble. Then slowly the bad arm remem­bers how too move. He learns to write again, to play ten­nis again: the func­tions of the brain areas killed in the stroke have trans­ferred them­selves to healthy regions.

The brain com­pen­sates for dam­age by reor­ga­niz­ing and form­ing new con­nec­tions between intact neu­rons. In order to recon­nect, the neu­rons need to be stim­u­lated through activity.

Plas­tic­ity, learn­ing and memory

For a long time, it was believed that as we aged, the con­nec­tions in the brain became fixed. Research has shown that in fact the brain never stops chang­ing through learn­ing. Plas­tic­ity is the capac­ity of the brain to change with learn­ing. Changes asso­ci­ated with learn­ing occur mostly at the level of the con­nec­tions between neu­rons. New con­nec­tions can form and the inter­nal struc­ture of the exist­ing synapses can change.

Did you know that when you become an expert in a spe­cific domain, the areas in your brain that deal with this type of skill will grow?

For instance, Lon­don taxi dri­vers have a larger hip­pocam­pus (in the pos­te­rior region) than Lon­don bus dri­vers (Maguire, Wool­lett, & Spiers, 2006). Why is that? It is because this region of the hip­pocam­pus is spe­cial­ized in acquir­ing and using com­plex spa­tial infor­ma­tion in order to nav­i­gate effi­ciently. Taxi dri­vers have to nav­i­gate around Lon­don whereas bus dri­vers fol­low a lim­ited set of routes.

Plas­tic­ity can also be observed in the brains of bilin­guals (Mechelli et al., 2004). It looks like learn­ing a sec­ond lan­guage is pos­si­ble through func­tional changes in the brain: the left infe­rior pari­etal cor­tex is larger in bilin­gual brains than in mono­lin­gual brains.

Plas­tic changes also occur in musi­cians brains com­pared to non-musicians. Gaser and Schlaug (2003) com­pared pro­fes­sional musi­cians (who prac­tice at least 1hour per day) to ama­teur musi­cians and non-musicians. They found that gray mat­ter (cor­tex) vol­ume was high­est in pro­fes­sional musi­cians, inter­me­di­ate in ama­teur musi­cians, and low­est in non-musicians in sev­eral brain areas involved in play­ing music: motor regions, ante­rior supe­rior pari­etal areas and infe­rior tem­po­ral areas.

Finally, Dra­gan­ski and col­leagues (2006) recently showed that exten­sive learn­ing of abstract infor­ma­tion can also trig­ger some plas­tic changes in the brain. They imaged the brains of Ger­man med­ical stu­dents three months before their med­ical exam and right after the exam and com­pared them to brains of stu­dents who were not study­ing for exam at this time. Med­ical stu­dents’ brains showed learning-induced changes in regions of the pari­etal cor­tex as well as in the pos­te­rior hip­pocam­pus. These regions of the brains are known to be involved in mem­ory retrieval and learning.

Q and A about Brain plas­tic­ity

Q: Can hor­mones change my brain?

A: It seems that the brain reacts to its hor­monal milieu with struc­tural mod­i­fi­ca­tions.

Q: Can new neu­rons grow in my brain?

A: Yes in some areas and through­out your life­time.

Q: Where can I find more information?

A: Read The Sharp­Brains Guide to Brain Fit­ness: 18 Inter­views with Sci­en­tists, Prac­ti­cal Advice, and Prod­uct Reviews, to Main­tain Your Brain Sharp to pro­vide a com­pre­hen­sive and acces­si­ble entry into the research and how to apply it.

"Check out the big brain on Brad." Pulp Fiction, 1994.

A link to the SharpBrains site for those that are interested:

http://www.sharpbrains.com/blog/2008/02/26/brain-plasticity-how-learning-changes-your-brain/