Diminished Empathic and Social Responses in Infancy As Early Markers of ASD Diagnosis
However, no study to date has examined empathic responding during the first year of life as a predictor of subsequent ASD diagnosis. This is likely because up until recently it has been assumed that empathic concern only emerges during the second year of life (Hoffman, 2001). But recent research shows that, contrary to this theoretical assumption, typically-developing infants can also express empathy for distressed others early in the first year of life (Roth-Hanania, Davidov, & Zahn-Waxler, 2011; Davidov et al., 2013). Reduced empathic responses during the first year should thus be studied as early markers of evolving ASD.
Objectives: The current study sought to investigate empathic abilities as early markers (prodromal signs) of ASD in a prospective longitudinal study of high risk infants. We predicted that empathic concern and social interest at 6-months would be negatively correlated with subsequent ASD diagnosis.
Methods: The sample consists of infants, siblings of children with ASD, assessed at age 6, 12 and 18-months. Here we present the results of the first 12 infants, who have completed the assessment so far, as an initial pilot sample of a larger cohort.
At 6-months, Infants' responses to two distress simulations (enacted by mother and experimenter) were assessed and blindly coded for empathic concern (on a 0-3 validated scale). Infants' social interest was also measured using an eye-tracking task examining preference for images of people vs. objects.
At 12-months, a clinical, neurological and developmental examination was performed including morphometric measurements and assessment of milestones.
At 18-months, diagnostic assessment of ASD was conducted (screeners- SACS, M-chat, Q-chat; ADOS-2). Two of the infants have been diagnosed with ASD, eight as typically-developing, and two with developmentally-delayed communicative abilities.
Results: Consistent with hypothesis, empathic concern at 6-months (for both simulations combined) was significantly negatively correlated with subsequent ASD diagnosis, r=-.77, p=.003. Moreover, at-risk infants later diagnosed had significantly lower empathic concern mean score compared to a large normative sample of typically-developing 6-month-olds that we have collected (N=155; respective means: 0.44 vs. 1.03, t=-2.33, p=.05). In contrast, the at-risk infants subsequently found to be typically-developing did not differ from the normative sample (1.12 vs. 1.03, t=.55, ns). Finally, in the people vs. objects task, there was a significant negative correlation between the tendency to prefer people (proportion of trials in which the infant first fixated on the person image) and subsequent ASD diagnosis, r=-.65, p=.044.
Conclusions: Empathic abilities and social interest in early infancy may be promising prodromal markers of subsequent ASD diagnosis in high risk infants. Additional research is needed to establish these early markers, which may promote early diagnosis and intervention.