Abstract
AIM: To examine visual engagement to social stimuli and response to joint attention in young children with neurofibromatosis type 1 (NF1) and typically developing peers (controls). METHOD: Forty-five preschool children were studied cross-sectionally (mean age [SD] = 4 years 3 months [10 months]), 25 with NF1 and 20 typically developing controls. Participants passively viewed two eye-tracking paradigms. The first measured participants' time to first social fixation and duration of attention to social stimuli. The second assessed response to joint attention by recording the time taken to fixate on the target of an actor's eye gaze and the percentage of time maintaining joint attention. RESULTS: Compared to typically developing controls, children with NF1 were slower to fixate on social information (Cohen's d = 1.03, 95% confidence interval [CI] = 0.40-1.65), spent less time attending to social stimuli (d = -0.60, 95% CI = -1.27 to -0.01), and were slower to establish joint attention (rank-biserial correlation r = -0.49, 95% CI = -0.79 to -0.19). Slower fixation to social stimuli was associated with elevated autism traits (r = 0.41, p = 0.03) and lower social adaptive functioning (r = -0.49, p = 0.02) in children with NF1. INTERPRETATION: Our findings in preschool children build on previous evidence of diminished attention to social information in school-age children with NF1 and could inform early interventions to ameliorate the impact of reduced social attention on everyday social functioning in this population.