Featured Research

from universities, journals, and other organizations

Autism Skews Developing Brain With Synchronous Motion And Sound

Date:
March 30, 2009
Source:
NIH/National Institute of Mental Health
Summary:
Individuals with autism spectrum disorders tend to stare at people's mouths rather than their eyes. Now, a study in 2-year-olds with the social deficit disorder suggests why they might find mouths so attractive: lip-sync -- the exact match of lip motion and speech sound. Such audiovisual synchrony preoccupied toddlers who have autism, while their unaffected peers focused on socially meaningful movements of the human body, such as gestures and facial expressions.

Individuals with autism spectrum disorders (ASD) tend to stare at people's mouths rather than their eyes. Now, an NIH-funded study in 2-year-olds with the social deficit disorder suggests why they might find mouths so attractive: lip-sync—the exact match of lip motion and speech sound.

Such audiovisual synchrony preoccupied toddlers who have autism, while their unaffected peers focused on socially meaningful movements of the human body, such as gestures and facial expressions.

"Typically developing children pay special attention to human movement from very early in life, within days of being born. But in children with autism, even as old as two years, we saw no evidence of this," explained Ami Klin, Ph.D., of the Yale Child Study Center, who led the research. "Toddlers with autism are missing rich social information imparted by these cues, and this is likely to adversely affect the course of their development."

Klin, Warren Jones, Ph.D., and colleagues at Yale, report the findings of their study, funded in part by the National Institute of Health's National Institute of Mental Health, online March 29, 2009 in the journal Nature.

For the first time, this study has pinpointed what grabs the attention of toddlers with ASDs," said NIMH Director Thomas R. Insel, M.D. "In addition to potential uses in screening for early diagnosis, this line of research holds promise for development of new therapies based on redirecting visual attention in children with these disorders."

A eureka moment in the research came when researchers followed up on a clue from children's responses to audiovisual synchrony embedded in a nursery rhyme cartoon.

While it was known that people with autism do not spontaneously orient to social signals, it was unclear what early-emerging mechanism may contribute to that. Nor was it clear exactly what they were attending to instead. To find out, Klin, Jones and colleagues tracked the eye movements of two-year-olds with and without the disorder while they looked at cartoon animations on split-screen displays.

The researchers borrowed a technique from the video game industry, called motion capture. They then reduced the movements to only points of light at each joint in the body, like animated constellations. These cartoons played normally – upright and forward – on one half of the screen, but upside-down and in reverse on the other half. The inverted presentation engages different brain circuits and is known to disrupt perception of biological motion in young children. The normal soundtrack of the actor's voice, recorded when the animations were made, accompanied the presentations.

Eye-tracking data initially showed that 21 toddlers with ASD had no preference for the upright animations, looking back and forth between the two. By contrast, 39 typically-developing toddlers and 16 developmentally delayed but non-autistic toddlers clearly preferred the upright animations.

However, responses to one animation didn't fit the pattern. The toddlers with ASD changed their behavior and shifted their attention to the upright figure as it played a game of pat-a-cake, where the figure claps his hands repeatedly. In this animation (see movie below), unlike the others, the movements of the points of light actually cause the clapping sound. This physical synchrony—dots colliding to produce a clapping sound—only existed on the upright side of the screen, because the inverted figure played in reverse and its motions weren't in sync with the soundtrack. The children with ASD chose the upright figure 66 percent of the time, a strong preference.

This clue led the researchers to suspect that what initially appeared to be random viewing by the ASD toddlers might actually reflect preference for audiovisual synchronies that were less obvious than the clapping. So they re-analyzed the data, factoring in more subtle synchronous changes in motion and sound.

"Audio-visual synchronies accounted for about 90 percent of the preferred viewing patterns of toddlers with ASD and none of unaffected toddlers," said Jones. "Typically-developing children focused instead on the most socially relevant information."

A follow-up experiment using new animations optimized for audiovisual synchrony confirmed these results.

Klin, Jones, and colleagues also recently reported that children with autism look more at peoples' mouths than eyes as early as age 2. Since the mouth is the facial feature with most audiovisual synchrony – lip motion with speech sound – the researchers propose that their new findings offer a likely explanation for this phenomenon.

"Our results suggest that, in autism, genetic predispositions are exacerbated by atypical experience from a very early age, altering brain development," said Klin. "Attention to biological motion is a fundamental mechanism of social engagement, and in the future, we need to understand how this process is derailed in autism, starting still earlier, in the first weeks and months of life."

NIMH is funding a related research project of Klin and Jones' that explores related behaviors in infants who have older siblings already diagnosed with ASD and who, because of the genetic heritability risk in autism, have greater risk of also developing the condition.

Also participating in the research were: David Lin, now at Harvard Medical School; Phillip Gorrindo, now at Vanderbilt University; Gordon Ramsay, Ph.D., Haskins Laboratories. The study was funded through the NIH's STAART Program (Studies To Advance Autism Research & Treatment).


Story Source:

The above story is based on materials provided by NIH/National Institute of Mental Health. Note: Materials may be edited for content and length.


Journal Reference:

  1. Klin A, Lin DJ, Gorrindo P, Ramsay G, Jones W. Two-year-olds with autism fail to orient toward human biological motion but attend instead to non-social physical contingencies. Nature, Mar 29, 2009

Cite This Page:

NIH/National Institute of Mental Health. "Autism Skews Developing Brain With Synchronous Motion And Sound." ScienceDaily. ScienceDaily, 30 March 2009. <www.sciencedaily.com/releases/2009/03/090329143314.htm>.
NIH/National Institute of Mental Health. (2009, March 30). Autism Skews Developing Brain With Synchronous Motion And Sound. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2009/03/090329143314.htm
NIH/National Institute of Mental Health. "Autism Skews Developing Brain With Synchronous Motion And Sound." ScienceDaily. www.sciencedaily.com/releases/2009/03/090329143314.htm (accessed September 2, 2014).

Share This




More Mind & Brain News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Can You Train Your Brain To Eat Healthy?

Can You Train Your Brain To Eat Healthy?

Newsy (Sep. 1, 2014) New research says if you condition yourself to eat healthy foods, eventually you'll crave them instead of junk food. Video provided by Newsy
Powered by NewsLook.com
Coffee Then Napping: The (New) Key To Alertness

Coffee Then Napping: The (New) Key To Alertness

Newsy (Aug. 30, 2014) Researchers say having a cup of coffee then taking a nap is more effective than a nap or coffee alone. Video provided by Newsy
Powered by NewsLook.com
Young Entrepreneurs Get $100,000, If They Quit School

Young Entrepreneurs Get $100,000, If They Quit School

AFP (Aug. 29, 2014) Twenty college-age students are getting 100,000 dollars from a Silicon Valley leader and a chance to live in San Francisco in order to work on the start-up project of their dreams, but they have to quit school first. Duration: 02:20 Video provided by AFP
Powered by NewsLook.com
Baby Babbling Might Lead To Faster Language Development

Baby Babbling Might Lead To Faster Language Development

Newsy (Aug. 29, 2014) A new study suggests babies develop language skills more quickly if their parents imitate the babies' sounds and expressions and talk to them often. 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