Birds Practice Singing in Sleep

Oct. 26 -- Birds and people may not have much in common, but we might share at least one experience: dreaming.

And songbirds dream of what they know best — singing.

“Dreaming is not a very scientific term,” says Daniel Margoliash, a biologist at the University of Chicago and principle investigator of the recent study in the journal Science. “But I think dreaming is a close description of what happens to the animal.”

Margoliash and the lead author, Amish Dave, a medical student at the University of Illinois, found that the brain cells of zebra finches fire in very similar patterns while the birds are sleeping and while they are singing. And there may be a reason why the zebra finches sing in their dreams — to help them remember their songs. Songs are critical for birds in attracting mates and marking territory.

Sleeping to Learn

Recent experiments in humans and rats have demonstrated a strong correlation between learning and sleeping. One study found that groups of neurons in rats fire the same patterns while the rats negotiate a maze wide-awake and then while they slumber. In another study, also published in Science, people learned how to play the computer game Tetris. Later, when the subjects went to sleep, they were awakened throughout the night and asked to reveal their dreams. Nearly all reported they were dreaming about the computer game.

By replaying the day’s events in dreams, scientists argue, the brain is able to coalesce information it has taken in during the day and make sense of it.

“Practically all the experiments coming out to date say that your mother is right — that you need sleep before you train and learn and, most importantly, after you train and learn,” says Robert Stickgold, the Harvard psychologist who conducted the Tetris study.

Stickgold suspects that sleep deprivation may play a big role in learning problems and even in brain disorders — such as Alzheimer’s disease — that occur later in life.