Infants who focus on mouths rather eyes could be autistic

Sep 28 2008

Researchers in the United States say young children who focus on mouths rather than on eyes could be autistic and they believe the extent of such behaviour indicates the severity of the Autism Spectrum Disorder.

The researchers at Yale School of Medicine found that two-year-olds with autism looked significantly more at the mouths of others, and less at their eyes, than other children.

The research team led by Warren Jones used eye-tracking technology to quantify the visual fixations of two-year-olds who watched caregivers approach them and engage in typical mother-child interactions.

The researchers say during the first week of life, typical human newborns give preferential attention to the eyes of others and studies in animals also suggests that attention to the eyes is an important factor in social development.

Children with autism, however, make far less eye contact and some will avoid it altogether.

In infancy and throughout life, the act of looking at the eyes of others is a window into people's feelings and thoughts and a powerful facilitator in shaping the formation of the social mind and brain.

The research team were interested in finding out what the earliest point of diagnosis in autism could be.

For the study a group of children, 15 with autism, 15 developmentally delayed but nonautistic and 36 typically developing children, were all shown videos where an actress looking directly into the camera, played the role of caregiver, engaging the viewer with games such as pat-a-cake and peek-a-boo.

The researchers then tracked and measured the children's visual fixation patterns to eyes, mouth, body, and object.

They found that with the autistic children looking at the eyes of others was significantly decreased in comparison with both the other groups and fixation on eyes by the children with autism correlated with their level of social disability - less fixation on eyes predicted greater social disability.

The researchers say looking at the eyes of others is important in early social development and in social adaptation throughout life and in children with autism, this behaviour is already derailed.

They suggest it offers a potential marker for quantifying the presence and severity of autism early in life and for screening infants for autism.

Jones, a research scientist from the Yale School of Medicine Interdepartmental Neuroscience Program and the Yale Child Study Center says their findings could aid research on the neurobiology and genetics of autism, work that is dependent on quantifiable markers of syndrome expression.

Researcher Ami Klin, director of the Autism Program at the Child Study Center, says they are now using the technology in a large prospective study of the younger siblings of children with autism, who are at greater risk of also developing the condition.

Klin says by following babies at risk of autism monthly from the time they are born, they hope to trace the origins of social engagement in human infants and to detect the first signs of derailment from the normal path.

Jones and Klin are also carrying out parallel research studies aimed at identifying the mechanisms underlying abnormal visual fixation in infants with autism.

They say autistic children's increased fixation on mouths possibly indicates a focus on the physical synchrony between lip movements and speech sounds, rather than on the social-affective context of the entreating eye gaze of others, suggesting a predisposition to seek physical, rather than social contingencies in their surrounding world.

Jones says autistic children may be seeing faces in terms of their physical attributes alone - watching a face without necessarily experiencing it as an engaging partner sharing in a social interaction.

The study is published in the Archives of General Psychiatry.