Human Brain's Seamless Backup Mechanism Observed
A new combination of neural imaging methods has been used by scientists at Carnegie Mellon University to discover exactly how the human brain adapts to injury.
The research shows that a "back-up" team of secondary brain areas immediately activates when one brain area loses functionality, replacing not only the unavailable area but also its confederates and allows the individual’s thought process to continue with no decrease in comprehension performance.
Functional magnetic resonance imaging (fMRI) was used by Robert Mason, senior research psychologist at CMU, and Chantel Prat to analyze 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 then 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, for which the Wernicke area is a key component, before, during and after the TMS was applied.
The dynamic data from the fMRI scans to measure how the brain activity changed immediately following stimulation to the Wernicke area showed the quick "rewiring" of the brains task areas to seamlessly continue operation.
"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 Just, who published the study with his collegues in the journal Cerebral Cortex.
Robert A. Mason, Chantel S. Prat, and Marcel Adam Just, Neurocognitive Brain Response to Transient Impairment of Wernicke’s Area, Cerebral Cortex, 2013, DOI: 10.1093/cercor/bhs423