Initiating joint attention in typical and atypical development: an eye tracking study

BACKGROUND Joint attention (JA) is the human ability to coordinate our attention with that of other people. It has been established that joint attention is impaired early in Autism Spectrum Disorder (ASD). The aim of this eye-tracking study was to evaluate the visual patterns during tasks eliciting responding joint attention and initiating joint attention in High Risk – non ASD (HR-nASD) subjects as compared to ASD and typical development (TD) children. METHODS Fifty-two children participated in the study: 17 ASD, 19 HR-nASD and 16 TD. The sample age range was 18-33 months. All subjects enrolled underwent a comprehensive clinical assessment and eye tracking experiments using three tasks: one for responding JA (RJA) and two tasks for initiating joint attention (IJA-1 and IJA-2). Fixations, Transitions and alternating gaze were analyzed. RESULTS In the RJA task only the number of transitions from face to non- target object was significantly different between the HR- nASD and ASD subjects (p=0,004) with lower values for the HR-nASD group. In the IJA1 task alternating gaze between target object and the model’s face was statistically different between HR-nASD and ASD subjects (p<0,001) as well as between TD and ASD subjects (p= 0,029). Alternating gaze between the non-target object and the model’s face and between non-target object and target object differed significantly between the HR-nASD and TD groups (p= 0,012 and p= 0,003, respectively) with lower values for the HR- nASD population. In the IJA2 task alternating gaze between face and target object differed significantly between HR-nASD and ASD subjects (p