Featured Research

from universities, journals, and other organizations

New Brain Mechanism Identified For Interpreting Speech

Date:
December 20, 2007
Source:
University of Chicago Medical Center
Summary:
In conversation, humans recognize words primarily from the sounds they hear. However, scientists have long known that what humans perceive goes beyond the sounds and even the sights of speech. The brain constructs its own unique interpretation. Scientists have now identified brain areas responsible for this perception. One of these areas, Broca's region, is typically thought of as an area of the brain used for talking rather than listening.

In conversation, humans recognize words primarily from the sounds they hear. However, scientists have long known that what humans perceive goes beyond the sounds and even the sights of speech. The brain actually constructs its own unique interpretation, factoring in both the sights and sounds of speech.

For example, when combining the acoustic patterns of speech with the visual images of the speaker's mouth moving, humans sometimes reconstruct a syllable that is not physically present in either sight or sound. Although this illusion suggests spoken syllables are represented in the brain in a way that is more abstract than the physical patterns of speech, scientists haven't understood how the brain generates abstractions of this sort.

Researchers at the University of Chicago have identified brain areas responsible for this perception. One of these areas, known as Broca's region, is typically thought of as an area of the brain used for talking rather than listening.

"When the speech sounds do not correspond exactly to the words that are mouthed, the brain often conjures a third sound as an experience -- and this experience may often vary from what was actually spoken," explains Uri Hasson, lead author of the study and a post-doctoral scholar at the university's Human Neuroscience Laboratory.

"As an example, what would happen if a person's voice says 'pa,' but the person's lips mouth the word 'ka"' One would think you might hear 'pa' because that is what was said. But in fact, with the conflicting verbal and visual signals, the brain is far more likely to hear 'ta,' an entirely new sound," he explains.

This demonstration is called the McGurk effect (named after Harry McGurk, a developmental psychologist from England who first noticed this phenomenon in the 1970s). In the current study, scientists used functional magnetic resonance imaging (graphic depiction of brain activity) to demonstrate that Broca's region is responsible for the type of abstract speech processing that underlies this effect.

Although we experience speech as a series of words like print on a page, the speech signal is not as clear as print, and must be interpreted rather than simply recognized, Hasson explains.

He says this paper provides a glimpse into how such interpretations are carried out in the brain. These types of interpretations might be particularly important, when the speech sounds are unclear, such as when conversing in a crowded bar, listening to an unfamiliar accent, or coping with hearing loss. "In all these cases, understanding what is said requires interpreting the physical speech signal to determine what is said. And scientists now know the Broca's region is plays a major role in this process."

Details of this study were published in the December 20th issue of Neuron. Additional authors include Jeremy Skipper, Howard Nusbaum and Steven Small of the University of Chicago.

The National Institute of Mental Health supported this research.


Story Source:

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


Cite This Page:

University of Chicago Medical Center. "New Brain Mechanism Identified For Interpreting Speech." ScienceDaily. ScienceDaily, 20 December 2007. <www.sciencedaily.com/releases/2007/12/071219122901.htm>.
University of Chicago Medical Center. (2007, December 20). New Brain Mechanism Identified For Interpreting Speech. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2007/12/071219122901.htm
University of Chicago Medical Center. "New Brain Mechanism Identified For Interpreting Speech." ScienceDaily. www.sciencedaily.com/releases/2007/12/071219122901.htm (accessed April 23, 2014).

Share This



More Mind & Brain News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
Powered by NewsLook.com
Do We Get Nicer With Age?

Do We Get Nicer With Age?

Newsy (Apr. 22, 2014) A recent report claims personality can change over time as we age, and usually that means becoming nicer and more emotionally stable. Video provided by Newsy
Powered by NewsLook.com
How to Master Motherhood With the Best Work/Life Balance

How to Master Motherhood With the Best Work/Life Balance

TheStreet (Apr. 22, 2014) In the U.S., there are more than 11 million couples trying to conceive at any given time. From helping celebrity moms like Bethanny Frankel to ordinary soon-to-be-moms, TV personality and parenting expert, Rosie Pope, gives you the inside scoop on mastering motherhood. London-born entrepreneur Pope is the creative force behind Rosie Pope Maternity and MomPrep. She explains why being an entrepreneur offers the best life balance for her and tips for all types of moms. Video provided by TheStreet
Powered by NewsLook.com
Sorry, Guys, Only Women Can Make Their Voices Sound Sexier

Sorry, Guys, Only Women Can Make Their Voices Sound Sexier

Newsy (Apr. 21, 2014) According to researchers at Albright College, women have the ability to make their voices sound sexier, but men don't. 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:
from the past week

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