Children with Autism Spectrum Disorders (ASDs) exhibit deficits in their ability to disengage visual attention and initiate joint attention. In similar fashion, the infant siblings of children with an ASD (ASD-sibs) engage in fewer shifts in visual attention and initiating fewer joint attention behaviors than the infant siblings of typically developing comparison children (COMP-sibs). Few studies have examined how these early deficits relate to one another and to later ASD severity in ASD-sibs.
To examine the developmental associations between early visual attention, joint attention, and ASD severity in ASD-sibs and COMP-sibs.
In the Face to Face-Still-Face Protocol (FFSF) at six months, parents were instructed to play normally with their infant, hold a still-face, and then resume play. Visual attention was measured as the frequency of infants’ gaze shifts at and away from the parent’s face during the FFSF. The mean number of initiations of joint attention was calculated during the Early Social Communication Scales (ESCS) at 8, 10, 12, 15, and 18 months of age. Later ASD severity was measured as a calibrated score on the Autism Diagnostic Observation Schedule (ADOS) at 30 months (Gotham et al., 2007).
For ASD-sibs, there were strong associations between early frequency of gaze shifts and later initiating joint attention, and between initiating joint attention and later ASD severity. ASD-sibs’ (n = 28) frequency of gaze shifts was significantly correlated with later initiating joint attention, r = .57, p <.01, such that higher frequency gaze shifting was associate with more initiating joint attention behaviors. For COMP-sibs (n = 19), that correlation was not significant, r =.09, p = .72. For ASD-sibs (n = 10) initiating joint attention was significantly correlated with ASD severity, r = -.64, p <.05, such that more initiating joint attention behaviors were related to lower ASD severity. For COMP-sibs (n = 10), that correlation was not significant, r = -.23, p = .51. There was no significant correlation directly between frequency of gaze shifts and ASD severity for either ASD-sibs or COMP-sibs.
Among ASD-sibs, flexible attention allocation at and away from the parent’s face at six months predicted later initiating joint attention, which in turn predicted ASD severity on the ADOS a year later. Comp-sibs did not show these associations, perhaps because attentional flexibility did not constrain initiating joint attention among typically developing children. Difficulties with flexible allocation of visual attention—an essential behavioral component of initiating joint attention-- may be an early index of developing difficulties among infants at-risk for autism.