Two scientists at the Stanford University School of Medicine have taken a big step toward sorting out how the brain accomplishes this task. In the Jan. 19 issue of Nature, the researchers show that a mechanism for prioritizing information - previously reported only in primates - is also used by birds.
"What our experiment demonstrates is a fundamental principle of how the brain pays attention," said the paper's senior author, Eric Knudsen, PhD, the Edward C. and Amy H. Sewall Professor of Neurobiology. "The promise here is that because we are doing this in owls, we can get at the mechanisms of how this works."
The study determined that the circuits in the brain that process auditory information are influenced powerfully by the circuits that control where the animal is looking-the animal's direction of gaze.
"The ability to hear and the direction of gaze aren't necessarily linked," said the paper's first author, postdoctoral scholar Daniel Winkowski, PhD. Sounds originating from any direction don't require visualization to be heard. "It's exciting to find that the circuits in the brain that control gaze direction affect how the brain processes auditory information," he added.
With funds from the National Institutes of Health, Winkowski and Knudsen used electrodes to stimulate the area of the brain responsible for controlling the direction of gaze in barn owls, and then studied how that affected the neural responses in regions of the brain that process auditory information. When the gaze control circuit was activated, they found that the owls' auditory system responded more strongly and more sele
Source:Stanford University Medical Center