A new study has found that autistic toddlers look significantly more at the mouths of others, and less at their eyes, as compared to their normal counterparts.
Led by researchers at Yale School of Medicine, the study suggests that this abnormality predicts the level of disability.
Study leaders Warren Jones, Ami Klin, and Katelin Carr 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, such as playing games like peek-a-boo.
The researchers say that infants start looking in the eyes of others after the first few weeks of life, beginning the processes of socialization.
They describe the act of looking at the eyes of others as a window into people's feelings and thoughts, and a powerful facilitator in shaping the formation of the social mind and brain.
According to them, the amount of time toddlers spent focused on the eyes predicts their level of social disability.
The researchers are of the view that their findings may offer a useful biomarker for quantifying the presence, and severity of autism early in life and screen infants for autism.
They also believe that scientists researching the neurobiology and genetics of autism may find their findings interesting.
"The findings offer hope that these novel methods will enable the detection of vulnerabilities for autism in infancy," said Jones, a research scientist from the Yale School of Medicine Interdepartmental Neuroscience Program and the Yale Child Study Center.
"We hope this technology can be used to detect and measure signs of an emerging social disability, potentially improving a child's outcome. Earlier intervention would capitalize on the neuroplasticity of the developing brain in infancy," the researcher added.
Ami Klin, director of the Autism Program at the Child Study Center, has revealed that the research team was planning to used their technology in a large prospective study of the younger siblings of children with autism, who are at greater risk of also developing the condition.
"By following babies at risk of autism monthly from the time they are born, we hope to trace the origins of social engagement in human infants and to detect the first signs of derailment from the normative path," said Klin.
The researchers are side-by-side conducting more studies to identify the mechanisms underlying abnormal visual fixation in infants with autism.
"Our working hypothesis is that these children's increased fixation on mouths points to a predisposition to seek physical, rather than social contingencies in their surrounding world. They 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," said Jones.
"These 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 researcher added.
A research article on the study has been published in the Archives of General Psychiatry.