SEATTLE -- It's a problem faced by people joining noisy parties and by midshipman fish seeking mates: How to cut through the racket and find Mr. Right?
Now Cornell University biologists, who became underwater disc jockeys to study a homely fish that hums, say they have a clue as to how mate selection works. The auditory portion of the midbrain uses the acoustic qualities of all the noise to isolate one signal it is programmed to recognize as potentially interesting.
The biologists' research applies only to midshipman fish, but it could, they say, also be relevant to people.
"Neuroscientists call this auditory scene analysis," says Andrew H. Bass, Cornell professor of neurobiology and behavior who will present his group's findings June 25 at the International Congress on Acoustics-Acoustical Society of America meeting in Seattle. "It's really very similar to the cocktail party effect."
In a way, midshipman fish have more problems than people at loud parties. Only some of the male midshipman hum (See "Humming Fish Facts," attached), and those males are hiding in cavitylike nests they have excavated under rocks. All the humming males together sound like a huge hive of bees or a squadron of motor boats, and a female midshipman fish has to choose one nest in which to deposit her eggs. When a humming male succeeds in attracting a female, he fertilizes her eggs, which adhere to the rocky ceiling of his nest. The female leaves forever, and the male resumes humming in hopes of attracting another female with more eggs.
Wondering how the female fish find the right males, the Cornell biologists examined the structure and function of midshipman brains. From earlier studies with Robert Baker at the New York University Medical School, Bass knew that a part of the midshipman male brain, called the hindbrain, contains neurons that constitute a kind of vocal pacemaker. Like a rhythm generator, the pacemaker tells the sound-generating
Contact: Roger Segelken
Cornell University News Service