Featured Research

from universities, journals, and other organizations

How Do We Hear While We Sleep?

Date:
April 30, 1998
Source:
Johns Hopkins University
Summary:
A Johns Hopkins University undergraduate has found the part of the brain that processes sound during sleep, waking a mother when her infant cries but letting her sleep on while a truck roars past.

Hopkins student finds place in the brain that 'listens' while we snooze

Using electrodes implanted directly on the human cortex, a Johns HopkinsUniversity undergraduate has located the part of the brain thatappears to process sounds while people sleep. This site, in thefrontal lobe, may be part of a vigilance system that, for instance, rouses amother when her baby cries but lets the woman sleep when a truckrumbles by.

Serena J. Gondek, a 21-year-old junior majoring in biomedicalengineering, is slated to present her findings on Tuesday, April28, at the annual meeting of the American Academy of Neurology inMinneapolis, Minn. About 8,000 people are expected to attend theworld's largest gathering of neurologists and neuroscienceprofessionals. Administrators at the academy said it is unusualfor an undergraduate to be chosen to make an oral researchpresentation at the event.

Previous studies on hearing during sleep have relied onelectrodes attached to a subject's shaved scalp. Gondek'sexperiment is believed to be the first of its type to useelectrodes implanted directly on the brain, a technique thatyields far more precise information about which parts areactivated by sounds during sleep.

Gondek is from the Chicago suburb of Oak Brook, Ill. Sheconducted her experiment under the supervision of Gregory L.Krauss, an assistant professor of neurology at the Johns HopkinsSchool of Medicine. Krauss is co-author of the paper, titled, "Howdo we hear while we sleep?"

"It is controversial how we monitor our environment while wesleep," says Krauss. "It's a pretty big part of our lives, butsleep is poorly understood. The main thing that Serena did was toshow where on the cortex we hear while we sleep. She did aterrific job, particularly in the brain mapping."

Gondek is the second Hopkins undergraduate in recent months topresent research findings at a major medical conference incollaboration with Krauss. "Undergraduates are great for thesekind of projects because they're very enthusiastic," says Krauss,"and they work very hard."

Hopkins professors often encourage undergraduates to take part inhigh-level scientific studies. "That's why I really lookedforward to coming to Hopkins," says Gondek, "It's been as easy asknocking on a few doors to become involved in research projects,even during my freshman year."

For her experiment, Gondek obtained the cooperation of fivepatients who were about to undergo brain surgery to curtailepileptic seizures. To find the focal points of these seizures, asurgeon had cut open the patients' skulls and implanted electrodegrids directly on their brains.

Prior to their surgery, Gondek placed special plugs in thepatients' ears. The plugs blocked out room noise but allowed thepatients to hear sequences of two tones emitted by Gondek'sequipment, one tone pitched at 500 hertz, the other at 1,000.

She played various tone patterns while the patients were awake,during light sleep and during deep sleep. The electrodes detectedwhich portions of the brain were activated. Gondek analyzed theresults and mapped them onto MRI and CT scans made of thepatients' brains.

"We found that during waking, only areas around primary auditorycortex are activated by the tones," she says. "Then, during lightand deep sleep, you find not only primary auditory activation,but the frontal lobe also responds."

The frontal lobe is believed to play a key role in vigilancefunctions, such as screening new stimuli and preparing the bodyto react. During sleep, Gondek speculates, this part of the brainmay analyze sounds to decide whether the person needs to beawakened to respond. This mechanism would allow a camper in thewoods to sleep through non-threatening cricket chirps. But itmight awaken the camper quickly to the growl of a bear.

Gondek and Krauss are planning follow-up experiments to learnmore about how the brain processes specific environmental soundsduring sleep. Their research may also shed light on connectionsbetween sleep disorders and mental illnesses such as depressionand dementia.

Finding the place where the brain processes sounds during sleephas been a critical first step to cracking a tough physiologicalpuzzle. "At this point," Gondek explains, "we can say that thisis where it's happening. But it's still very unclear what's goingon there, how this processing works."

Her project was supported by a General Electric FoundationUndergraduate Engineering Research Stipend.

###

Reporters, please note: Color slides are available. Contact Phil Sneiderman atthe phone number or e-mail address at the top of this release.


Story Source:

The above story is based on materials provided by Johns Hopkins University. Note: Materials may be edited for content and length.


Cite This Page:

Johns Hopkins University. "How Do We Hear While We Sleep?." ScienceDaily. ScienceDaily, 30 April 1998. <www.sciencedaily.com/releases/1998/04/980430044534.htm>.
Johns Hopkins University. (1998, April 30). How Do We Hear While We Sleep?. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/1998/04/980430044534.htm
Johns Hopkins University. "How Do We Hear While We Sleep?." ScienceDaily. www.sciencedaily.com/releases/1998/04/980430044534.htm (accessed October 20, 2014).

Share This



More Mind & Brain News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Your Birth Season Might Determine Your Temperament

Your Birth Season Might Determine Your Temperament

Newsy (Oct. 20, 2014) A new study says the season you're born in can determine your temperament — and one season has a surprising outcome. Video provided by Newsy
Powered by NewsLook.com
Court Ruling Means Kids' Online Activity Could Be On Parents

Court Ruling Means Kids' Online Activity Could Be On Parents

Newsy (Oct. 17, 2014) In a ruling attorneys for both sides agreed was a first of its kind, a Georgia appeals court said parents can be held liable for what kids put online. Video provided by Newsy
Powered by NewsLook.com
The Best Foods To Boost Your Mood

The Best Foods To Boost Your Mood

Buzz60 (Oct. 17, 2014) Feeling down? Reach for the refrigerator, not the medicine cabinet! TC Newman (@PurpleTCNewman) shares some of the best foods to boost your mood. Video provided by Buzz60
Powered by NewsLook.com
You Can Get Addicted To Google Glass, Apparently

You Can Get Addicted To Google Glass, Apparently

Newsy (Oct. 15, 2014) Researchers claim they’ve diagnosed the first example of the disorder in a 31-year-old U.S. Navy serviceman. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins