According to a recent ASA announcement, Anu Sharma, PhD, a researcher in the Department of Speech Language and Hearing Science at University of Colorado, applied fundamental principles of neuroplasticity to determine how the brain adapts to hearing loss, as well as the consequences of those changes.
Sharma and colleagues in the Brain and Behavior Laboratory used electroencephalographic (EEG) recordings of adults and children with deafness and lesser hearing loss to gain insights into the ways their brains respond differently from those of people with normal hearing.
Adults with early-stage age-related hearing loss (right) show decreased activation of the hearing portion of the brain compared with normal hearing age-matched adults (left).
Sharma explained via the ASA announcement that EEG recordings involve placing multiple tiny sensors on the scalp, which allows researchers to measure brain activity in response to sound simulation. For her study, sound simulation, such as recorded speech syllables, was delivered via speakers to elicit a response in the form of “brain waves” that originate in the auditory cortex—the most important center for processing speech and language—and other areas of the brain.
Adults with mild age-related hearing loss (right) show brain reorganization in hearing portions of brain, which are recruited for processing visual patterns. This is not seen in age-matched adults with normal hearing (left).
“We can examine certain biomarkers of cortical functioning, which tell us how the hearing portion of a deaf person’s brain is functioning compared to a person with normal hearing,” Sharma said.
ASA reports that Sharma and other researchers have recently discovered that the areas of the brain responsible for processing vision or touch can recruit areas in which hearing is normally processed, but which receive little or no stimulation in deafness. This is called “cross-modal” cortical reorganization and reflects a fundamental property of the brain to compensate in response to its environment.
- See more at: http://www.hearingreview.com/2015/05/researchers-discover-brain-reorganizes-hearing-loss/#sthash.UpMFY7oZ.dpuf