Featured Research

from universities, journals, and other organizations

Perceptual Rivalry: Nostrils Alternate To Process Competing Odors

Date:
August 24, 2009
Source:
Rice University
Summary:
When the nose encounters two different scents simultaneously, the brain processes them separately through each nostril in an alternating fashion. This finding is the first demonstration of "perceptual rivalry" in the olfactory system.

When the nose encounters two different scents simultaneously, the brain processes them separately through each nostril in an alternating fashion.
Credit: iStockphoto

When the nose encounters two different scents simultaneously, the brain processes them separately through each nostril in an alternating fashion.

Related Articles


This finding by researchers at Rice University in Houston is the first demonstration of "perceptual rivalry" in the olfactory system. The study was published online August 20 by the journal Current Biology and will appear in the Sept. 29 print edition.

"Our discovery opens up new avenues to explore the workings of the olfactory system and olfactory awareness," said Denise Chen, assistant professor of psychology, who coauthored the research paper with graduate student Wen Zhou.

For the study, 12 volunteers sampled smells from two bottles containing distinctively different odors. One bottle had phenyl ethyl alcohol, which smells like a rose, and the other had n-butanol, which smells like a marker pen. The bottles were fitted with nosepieces so that volunteers could sample both scents simultaneously -- one through each nostril.

During 20 rounds of sampling, all 12 participants experienced switches between smelling predominantly the rose scent and smelling predominantly the marker scent. Some experienced more frequent and drastic switches than others, but there was no predictable pattern of the switch across the whole group of volunteers or within individuals.

Chen said this "binaral rivalry" between the nostrils resembles the rivalry that occurs between other pairs of sensory organs. When the eyes simultaneously view two different images -- one for each eye -- the two images are perceived in alternation, one at a time. And when alternating tones an octave apart are played out of phase to each ear, most people experience a single tone that goes back and forth from ear to ear.

In the laboratory setting in which each nostril simultaneously received a different smell, the participants experienced an "olfactory illusion," she said. "Instead of perceiving a constant mixture of the two smells, they perceive one of the smells, followed by the other, in an alternating fashion, as if the nostrils were competing with one another. Although both smells are equally present, the brain attends to predominantly one of them at a time."

"The binaral rivalry involves adaptations at the peripheral sensory neurons and in the cortex," Chen said. "Our work sets the stage for future studies of this phenomenon so we can learn more about the mechanisms by which we perceive smells."

In binaral rivalry, the tug-of-war between dominance and suppression of the olfactory perception exists only in the mind of the person who smells the odors, while the physical properties of the olfactory stimuli remain unchanged, Chen said. This gives humans the rare opportunity to dissociate olfactory perception and physical stimulation. As such, binaral rivalry may offer a unique window into consciousness and awareness in both healthy and ill people.

Human olfaction is a subject very much in its infancy. Chen said understanding the mechanisms with which people process olfactory information is not only important to basic science, but may also, over the long run, contribute to the assessment and cure of olfactory disorders in patients and, in particular, the elderly.


Story Source:

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


Cite This Page:

Rice University. "Perceptual Rivalry: Nostrils Alternate To Process Competing Odors." ScienceDaily. ScienceDaily, 24 August 2009. <www.sciencedaily.com/releases/2009/08/090820124050.htm>.
Rice University. (2009, August 24). Perceptual Rivalry: Nostrils Alternate To Process Competing Odors. ScienceDaily. Retrieved April 18, 2015 from www.sciencedaily.com/releases/2009/08/090820124050.htm
Rice University. "Perceptual Rivalry: Nostrils Alternate To Process Competing Odors." ScienceDaily. www.sciencedaily.com/releases/2009/08/090820124050.htm (accessed April 18, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Saturday, April 18, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Our Love Of Puppy Dog Eyes Explained By Science

Our Love Of Puppy Dog Eyes Explained By Science

Newsy (Apr. 17, 2015) Researchers found a spike in oxytocin occurs in both humans and dogs when they gaze into each other&apos;s eyes. Video provided by Newsy
Powered by NewsLook.com
Scientists Find Link Between Gestational Diabetes And Autism

Scientists Find Link Between Gestational Diabetes And Autism

Newsy (Apr. 17, 2015) Researchers who analyzed data from over 300,000 kids and their mothers say they&apos;ve found a link between gestational diabetes and autism. Video provided by Newsy
Powered by NewsLook.com
Video Messages Help Reassure Dementia Patients

Video Messages Help Reassure Dementia Patients

AP (Apr. 17, 2015) Family members are prerecording messages as part of a unique pilot program at the Hebrew Home in New York. The videos are trying to help victims of Alzheimer&apos;s disease and other forms of dementia break through the morning fog of forgetfulness. (April 17) Video provided by AP
Powered by NewsLook.com
Common Pain Reliever Might Dull Your Emotions

Common Pain Reliever Might Dull Your Emotions

Newsy (Apr. 16, 2015) Each week, millions of Americans take acetaminophen to dull minor aches and pains. Now researchers say it might blunt life&apos;s highs and lows, too. 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