Autistic spectrum disorders (ASD) affect 1/88 people. Autism is highly heritable and is believed to be a congenital condition. Hundreds of genes are likely to be involved, and disruption caused by these (any/combination/all ) can lead to deviation from normal development process. In normal babies, social interaction emerge in first hours/weeks (preferential attention to familiar voices, faces, face-like stimuli, and biological motion) and is the foundation for socialisation.
Deficits in eye contact is a diagnostic feature of autism. How early ie before the onset of overt symptoms, does these defects appear ? Warren Jones and Ami Klin report the results of preliminary study that has revealed an interesting observation.
They measured preferential attention to the eyes of others in 59 infants at high risk (full siblings of a child with ASD) and 51 low risk infants. While infants viewed scenes of naturalistic care- giver interaction their visual scanning was measured with eye-tracking equipment.These were recorded from second month onwards. At 36 months, 20% of high risk group met criteria for autism.
Findings: In children who were later diagnosed with autism , eye fixation declines from month 2 and until month 24 and reach at a level that is approximately half that of typically developing children by 24 months. Early levels of eye looking seem to begin at normative levels. This was an unexpected finding. This contradicts prior hypotheses of a congenital absence of social adaptive orientation in autism. This window of time correlates with the shift from experience-expectant to experience-dependent mechanisms observed in animal studies. The findings need to be confirmed in larger samples.
Conclusion: If social adaptive mechanism is present at birth an intact until age 2 months, this would offer a remarkable opportunity for treatment. If the neural foundation for socialisation is there, ( i.e. not absent as believed before), interventions might help before the transition happens.
Summary of the article:
Jones W, Klin A. Nature. 2013 Nov 6