Friday, 31 October 2014

Brain Plasticity: How Learning Changes Your Brain Fast

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).

neuroplasticity and brain researchIn 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 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 3 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.

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