Using Songbirds, Researchers Demonstrate That Sleeping Consolidates Learning (VIDEO)
Sleeping will aid the brain's ability to consolidate learning when two competing tasks are learned the in the same day, according to new research from the University of Chicago.
Researchers studied starlings' ability to recognize new songs; the songbirds well regarded for their ability to mimic sounds they hear. They are commonly kept as pets.
Other studies have demonstrated that sleep will consolidate learning for a new task. But this study, which measured starlings' ability to recognize new songs, shows that learning a second task can undermine the performance of the previously learned task, a University of Chicago news release states. The study is the first to show that a good night's sleep helps the brain retain both new memories.
"These observations demonstrate that sleep consolidation enhances retention of interfering experiences, facilitating daytime learning and the subsequent formation of stable memories," the authors wrote.
According to the study authors, starlings are an excellent model for studying memory because of fundamental biological similarities between avian and mammalian brains.
For the study, 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 preform a different pair of songs, the news release stated.
After learning a second pair of songs, the starlings were tested at various time intervals on the first pair of songs before going to sleep.
The birds had difficulty remembering the first pair of songs after being taught the second pair, regardless of the time lapse between the testing periods, the research found.
After the birds slept, they exhibited increased performance of both song sets, which suggests sleep consolidation enhances memory and overcomes the effects of interference. When researchers taught the birds a new set of songs after awaking, the birds were still able to remember what they learned the previous day, despite the interference.
"The study demonstrates that sleep restores performance and makes learning robust against interference encountered after sleep. This process is critical to the formation and stability of long-term memories," the authors said.
The paper was authored by University of Chicago researchers Howard Nusbaum, a leading expert on learning, and Daniel Margoliash who researches brain function and its development in birds. Graduate researcher Timothy Brawn was also credited as an author.
The paper, "Sleep Consolidation of Interfering Auditory Memories in Starlings," published in the current online edition of Psychological Science.