Owlets Sleep Like Human Babies

Rock-a-bye owlet, in the treetop …

Baby owls and baby mammals, including humans, sleep in an analogous manner, spending a similar amount of time in an awakelike phase called REM (rapid-eye movement), in which dreams are thought to occur, at least during adulthood, new research suggests.

In both owls and humans, REM sleep decreases with increasing age. Baby humans spend about 50 percent of their snooze time in this REM phase, whereas that figure decreases to less than 25 percent in adults, according to a statement from the Max Planck Institute for Ornithology. (Applying the REM term to owls, whose eyes are fixed in their heads, may seem a stretch, but researchers use the phrase anyway.)

In the new study, published in July in the journal Frontiers in Zoology, the researchers attached electroencephalograms (EEGs) and movement data loggers to 66 young barn owls to record how much time the animals spent in REM sleep and how much they moved while snoozing. They later removed the EEGs, which measure brain waves, and found that the birds mated normally and didn't appear to have suffered any negative effects from the devices, the statement noted.

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Sleep Consolidation of Interfering Auditory Memories in Starlings

Mar. 20, 2013 — Sleep plays an important role in the brain's ability to consolidate learning when two new potentially competing tasks are learned in the same day, research at the University of Chicago demonstrates.

Other studies have shown that sleep consolidates learning for a new task. The new study, which measured starlings' ability to recognize new songs, shows that learning a second task can undermine the performance of a previously learned task. But this study is the first to show that a good night's sleep helps the brain retain both new memories.

Starlings provide an excellent model for studying memory because of fundamental biological similarities between avian and mammalian brains, scholars wrote in the paper, "Sleep Consolidation of Interfering Auditory Memories in Starlings," published in the current online edition of Psychological Science.

"These observations demonstrate that sleep consolidation enhances retention of interfering experiences, facilitating daytime learning and the subsequent formation of stable memories," the authors wrote.

The paper was written by Timothy Brawn, a graduate researcher in psychology at UChicago; Howard Nusbaum, professor of psychology; and Daniel Margoliash, professor of psychology, organismal biology and anatomy. Nusbaum is a leading expert on learning, and Margoliash is a pioneer in the research of brain function and its development in birds.

For the study, the researchers conducted two experiments using 24 starlings each. They played two recorded songs from other starlings and tested the birds' ability to recognize and repeat the two songs. After learning to recognize the two songs, the birds were later trained to recognize and perform a different pair of songs.

Continued:  http://www.sciencedaily.com/releases/2013/03/130320133236.htm