Thu Oct 17, 2002
NEW YORK (Reuters Health) - People with autism focus on a speaker's eyes only half as often as other listeners do, letting their gaze fall more often on a speaker's mouth or body, US researchers report.
This behavior may help explain why autistics often have problems relating to others, according to Dr. Ami Klin and his colleagues from Yale University in New Haven, Connecticut.
Eyes convey important, silent cues about what a person is thinking and feeling, they write, and, sometimes, information gleaned from eyes can contradict what a person says with his mouth. Focusing on the mouth over the eyes, therefore, may cause autistic people to miss certain nuances of communication, potentially leading to social difficulties, Klin's team notes.
The differences in gazing patterns between autistics and non-autistics appears early: even in infancy, babies without autism begin to focus on people more often than objects, and their eyes will linger longer on a person's eyes than the mouth. Measuring where a baby's concentration lies, therefore, could allow doctors to diagnose autism within the first few months of life. And the earlier autism is diagnosed and treated, researchers say, the better the person could fare.
Klin and colleagues obtained their findings from 15 autistic men and 15 men without the condition, observing them as they watched scenes of intricate social interactions from the film "Who's Afraid of Virginia Woolf." The authors employed eye-tracking technology to determine how much time observers spent watching a speaker's mouth, eyes and body, and what portion of their concentration was spent fixed on inanimate objects.
The investigators found that people with autism concentrated on mouths, bodies and objects twice as often as others, but focused on eyes only half as often as non-autistics. Comparing gaze patterns to social competence, the authors also found that how well an autistic person fared in social situations was linked to the proportion of time he spent looking at a speaker's mouth, with more socially competent individuals tending to focus more often on the mouth.
In contrast, the longer autistic people spent gazing at objects during the emotional scenes from the movie, the more likely they were to have difficulties in social situations, the authors report in a recent issue of Archives of General Psychiatry.
Eyes offer a wealth of subtle social clues, so the fact that autistics who fared better socially focused more on the speakers' mouths seems contradictory--but may also make sense, the researchers explain.
"Given the well-known association between level of verbal skills and better outcome in autism, it is possible that the participants in our study were focusing on mouths because that is where speech comes from," Klin's team writes.
"By concentrating their efforts on something that they can understand, they might attain better understanding of social situations," they add.
However, that technique is "not without its limitations," the report indicates, given that it prevents autistic people from picking up on certain nuances of communication seen only in a speaker's eyes.
SOURCE: Archives of General Psychiatry 2002;59:809-816.