Diagnostic Imaging Online
January 23, 2003
Researchers map music hot spots in the brain
Wonder why you can't get that new Eminem song out of your head? Researchers at Dartmouth College have come one step closer to discovering why some tunes get stuck in your brain.
Using fMRI, the researchers discovered that people store knowledge of harmonic relationships in the rostromedial prefrontal cortex and not in the temporal lobe where basic sounds are processed.
"The rostromedial prefrontal cortex is believed to integrate emotional, cognitive, and visceral information," said Petr Janata, Ph.D., a research assistant professor of psychological and brain sciences at Dartmouth. "It is also one of the 'hottest' areas in the brain during rest, meaning that it shows a high level of metabolic activity during alert resting states, such as during spontaneous thought."
Janata and colleagues scanned each of eight subjects three times, with about one week between the scans. All the subjects had some level of musical experience.
During the scan, the researchers asked the listeners to perform two perceptual tasks while listening to a melody composed by one of the researchers, Jeffrey Birk. The melody went through all of the 24 major and minor keys.
For the first task, the listeners responded whenever they heard a note played by a flute instead of a standard clarinet. For the second task, they responded whenever they perceived notes that violated the local tonality.
The listeners were asked to perform the two different tasks while listening to the same piece of music, so the researchers could identify those areas of the brain that exhibit tonality tracking independent of the task being performed. The study was published in the December 13 issue of Science.
"Because the relationships among musical keys can be represented geometrically as a torus, we are able to model how a melody that we composed for the experiment should activate our representation of musical keys," Janata said.
As to how this affects why certain tunes stick in your brain, the only link so far is guilt by association.
"The observation that musical space is represented in brain regions that are highly active during spontaneous thought raises the hypothesis that these regions are, in part, where melodies might be spontaneously called to mind," Janata said.
For more information from Diagnostic Imaging online:
RSNA preview: MR maps new territory in brain
fMRI allows study of language processing
-- By Merlina Trevino
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