Individuals with autism often present with a narrow focus of attention and interest, as well as acute perception for details. Unlike neurotypical individuals, the cognitive processing style in autism favors details and locally configured information. Sometimes, this results in a competitive edge on tasks that benefit from these abilities.
In brain imaging studies of adults with autism, increased activation of sensory ventral-occipito-temporal areas and decreased activation in prefrontal areas are common. These patterns are typically described as evidence of preference for processing local, versus global, information.
The origins of this narrow processing style in autism can be attributable to difficulties in visual attention. Typically developing children learn to flexibly scan their environment and switch attention between different objects, which allows them to process global forms effectively. Infants with autism may lack this ability.
The pool of evidence accrued up to this time indicates that infants diagnosed with autism as toddlers show few differences in their behavior at 6 months but begin to show observable differences by about 12 months of age. Specific observable differences in behavior of children with autism include atypical social interactions, such as unusual eye contact, lack of orientation to child’s own name, and poor motor control.
A recent study which engaged infants 6-10 months old and the same infants at 12-15 month old mark showed that reduced flexibility in the control of visual attention is the early emerging feature of autism (Elsabbagh et al., 2013). The researchers found that infants who would be later diagnosed with autism spectrum disorder took longer to disengage from a centrally presented visual stimulus to look at a peripheral object. Consistent with this findings, some previous studies pointed out that preference for repetitive boring fixation stimulus was linked to greater impairment of social and communication skills at age 3.
Parents, however, should not diagnose their child with autism based on visual processing issues alone. Per CDC guidelines, a diagnosis of autism can be reliably made by age 2, so it will take a little bit of time and a lot of observations to arrive at the diagnostic conclusion.
For CDC developmental milestones tracker, please visit their page
Sources
CDC Digital Online Checklist, https://www.cdc.gov/ncbddd/actearly/milestones/digital-online-checklist.html
Elsabbagh, M., Fernandes, J., Webb, S. J., Dawson, G., Charman, T., Johnson, M. H., & British Autism Study of Infant Siblings Team. (2013). Disengagement of visual attention in infancy is associated with emerging autism in toddlerhood. Biological psychiatry, 74(3), 189-194.
M. Elsabbagh, K. Holmboe, T. Gliga, E. Mercure, K. Hudry, T. Charman, et al. (2011). Social and attention factors during infancy and the later emergence of autism characteristics. Prog Brain Res, 189, pp. 195-207