BOB HIRSHON (host):
Ringing in the brain…I’m Bob Hirshon and this is Science Update.
Tinnitus, or ringing in the ears, is triggered by hearing loss, and the brain’s attempt to fill the missing frequencies with sound of its own. In most cases, the brain’s limbic system keeps us from actually hearing this noise. But Georgetown University Medical Center neuroscientist Josef Rauschecker and his colleagues scanned the brains of chronic tinnitus patients using functional magnetic resonance imaging, or fMRI, and found that their limbic systems were focusing on the sounds, rather than filtering them out. He also found a connection between tinnitus and mood.
JOSEF RAUSCHECKER (Georgetown University Medical Center):
The limbic system is considered the neural substrate of emotions and mood. If you’re in a negative mood we have more tinnitus.
In addition to tinnitus, the research may lead to new insights into chronic pain, which may also be caused by the limbic system’s inability to filter out unneeded signals. I’m Bob Hirshon, for AAAS, the science society.