American scientists have for the first time used a new combination of neural imaging methods to discover exactly how the human brain adapts to injury.
The research, carried out at Carnegie Mellon University's Center for Cognitive Brain Imaging (CCBI), shows that when injury causes one area of the brain to lose function, secondary brain areas activate to fill in the gap.
"The human brain has a remarkable ability to adapt to various types of trauma, such as traumatic brain injury and stroke, making it possible for people to continue functioning after key brain areas have been damaged," said Marcel Just, the D. O. Hebb Professor of Psychology at CMU and CCBI director.
"It is now clear how the brain can naturally rebound from injuries and gives us indications of how individuals can train their brains to be prepared for easier recovery. The secret is to develop alternative thinking styles, the way a switch-hitter develops alternative batting styles. Then, if a muscle in one arm is injured, they can use the batting style that relies more on the uninjured arm."
For the study, Just, Robert Mason, senior research psychologist at CMU, and Chantel Prat, assistant professor of psychology at the University of Washington, used functional magnetic resonance imaging (fMRI) to study precisely how the brains of 16 healthy adults adapted to the temporary incapacitation of the Wernicke area, the brain's key region involved in language comprehension.
They applied Transcranial Magnetic Stimulation (TMS) in the middle of the fMRI scan to temporarily disable the Wernicke area in the participants' brains. The participants, while in the MRI scanner, were performing a sentence comprehension task before, during and after the TMS was applied. Normally, the Wernickearea is a major player in sentence comprehension.
The research team used the fMRI scans to measure how the brain activity changed immediately following stimulation to the Wernicke area.
The results showed that as the brain function in the Wernicke area decreased following the application of TMS, a "back-up" team of secondary brain areas immediately became activated and coordinated, allowing the individual's thought process to continue with no decrease in comprehension performance.
The study has been published in Cerebral Cortex. (ANI)