When they look at models who are looking toward them versus away from them, the variation in brain activity in infants who later develop Autism Spectrum Disorders (ASD) is different than that of their peers who do not develop ASD, according to Mayada Elsabbagh and colleagues in a study published in Current Biology. Infants who do not later develop ASD apparently are already tuning into whether human-like models are looking at them, but those who develop ASDs are doing so to a lesser degree.
Professor Elsabbagh studied 104 children, about half of whom were classified as at risk for ASD because they had an older sibling who had an ASD. They initially tested them at six months of age and, later, broke them into four groups: (a) A control group, (b) children who were at-risk but had not developed ASD by age three, (c) children who were at-risk and developed ASD symptoms by age three, and (d) children who were at-risk and developed ASD early.
At 6 to 10 months of age, the brain activity of the infants in the control group and the at-risk-without-ASD group already showed sensitivity to whether a model was looking toward or away from the children. However, the brain activity of infants who later developed ASD showed less sensitivity. The accompanying graph illustrates the results on one of their measures. (Note that the measure shown in the figure here is not the one of greatest interest to the researchers.)
Even though it is difficult to find overt behavioral markers of ASD during the first year of life, these findings support the idea that there are brain function measures that can discriminate between groups of infants at risk for ASD. It’s important to note that these data are at the group level. They can’t be taken at the individual level, so the data are not ready for diagnostic purposes.
The researchers included a group from the collaborative network supporting research with infants at risk for autism in the UK, the British Autism Study of Infant Siblings (BASIS). This group and comparable groups elsewhere are wonderful partners for research and deserve great credit for the collaboration in efforts such as this.
Here is the abstract from the article:
Autism spectrum disorders (henceforth autism) are diagnosed in around 1% of the population [1]. Familial liability confers risk for a broad spectrum of difficulties including the broader autism phenotype (BAP) [ [2] and [3]]. There are currently no reliable predictors of autism in infancy, but characteristic behaviors emerge during the second year, enabling diagnosis after this age [ [4] and [5]]. Because indicators of brain functioning may be sensitive predictors, and atypical eye contact is characteristic of the syndrome [ [6], [7], [8] and [9]] and the BAP [ [10] and [11]], we examined whether neural sensitivity to eye gaze during infancy is associated with later autism outcomes [ [12] and [13]]. We undertook a prospective longitudinal study of infants with and without familial risk for autism. At 6–10 months, we recorded infants’ event-related potentials (ERPs) in response to viewing faces with eye gaze directed toward versus away from the infant [14]. Longitudinal analyses showed that characteristics of ERP components evoked in response to dynamic eye gaze shifts during infancy were associated with autism diagnosed at 36 months. ERP responses to eye gaze may help characterize developmental processes that lead to later emerging autism. Findings also elucidate the mechanisms driving the development of the social brain in infancy.
Elsabbagh, M., Mercure1, E., Hudry, K., Chandler, S., Pasco, G., Charman, T.,…the BASIS Team. (2012). Infant neural sensitivity to dynamic eye gaze is associated with later emerging autism. Current Biology. Advance online publication. doi:10.1016/j.cub.2011.12.056
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