Scientists at Carnegie Mellon University's Center for Cognitive Brain Imaging have used a new neural imaging technique to show how the human brain adapts to injury.
In a study published in the journal Cerebral Cortex, the researchers demonstrated that when one area of the brain loses function, secondary areas of the brain activate to fill in the gap.
Led by Robert Mason, a senior research psychologist at the school, functional MRI was used to study 16 healthy adults who had to adapt to the loss of function of the Wernicke area of the brain, the region critical to language comprehension. The researchers used transcranial magnetic stimulation (TMS) in the middle of an MRI scan to temporarily incapacitate the Wernicke area of patients, who were performing language comprehension tasks before, during and after the time TMS was applied.
The researchers found that as brain function in the Wernicke area decreased following the application of TMS, other "back-up" areas of the brain activated and allowed the patients to continue with the language comprehension task, with no loss of performance. These back-up areas included contralateral areas, which are areas in the mirror-image location of the brain; areas right next to the impaired area; and the frontal executive area.
Their research also showed that impairment of the Wernicke area impacted cortical partners with which the Wernicke area was working.
"Thinking is a network function," study author Marcel Just, director of the Center for Cognitive Brain Imaging, said in an announcement. "When a key node of a network is impaired, the network that is closely collaborating with the impaired node is also impaired. People do their thinking with groups of brain areas, not with single brain areas."
Just said the human brain has "a remarkable ability to adapt to various types of trauma ... making it possible for people to continue functioning after key brain areas have been damaged. 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," Just added, "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."