Multimedia Gallery

Your Brain Is Always Listening

This is The Discovery Files, from the U.S. National Science Foundation.

Did you know that, even while you are sound asleep, your brain continues to listen to the sounds around you?

Some scientists believe this is a feature of the brain that alerts us to possible danger.

A new study revealed distinct differences in the way the brain processes sound while asleep, compared to when awake.

Funded in part by NSF, researchers at UCLA were seeking to understand the signals generated by the brain, in response to music and other sounds, during sleep versus waking hours.

The researchers monitored the brain activity of volunteer participants. They measured their brains' responses to both music and words, when the participants were awake and asleep.

During both states, the listening brain performs like an orchestra of neurons that never stops encoding incoming sounds.

Although researchers observed auditory responses in the sleeping brain were similar to those in a wakeful state, they found a key component was missing: "the conductor," the feedback signals from the higher regions of the brain that focus on, regulate and interpret incoming sounds when a participant was awake.

This discovery suggests the brain's feedback signals are essential to conscious sensory processing and could lead to better understanding of the role of "the conductor" and how people process sensory information in all modes.

It may also lead to new methods to improve our memory while we sleep.

Discover how the U.S. National Science Foundation is advancing research at nsf.gov. And check out NSF's Discovery Files podcast, available wherever you get podcasts.

"The discovery files" covers projects funded by the government's National Science Foundation. Federally sponsored research -- brought to you, by you! Learn more at nsf.gov or on our podcast.

Images and other media in the National Science Foundation Multimedia Gallery are available for use in print and electronic material by NSF employees, members of the media, university staff, teachers and the general public. All media in the gallery are intended for personal, educational and nonprofit/non-commercial use only.

Images credited to the National Science Foundation, a federal agency, are in the public domain. The images were created by employees of the United States Government as part of their official duties or prepared by contractors as "works for hire" for NSF. You may freely use NSF-credited images and, at your discretion, credit NSF with a "Courtesy: National Science Foundation" notation.

Additional information about general usage can be found in Conditions.