Social Attention, Higher Functioning ASD, and ADHD Symptoms

Background:   Autism Spectrum Disorder is characterized by deficits in social attention. However, it may not be possible to unambiguously identify attention deficits in studies of higher functioning children because many of these children also present with elevated symptoms associated with ADHD.  

Objectives:   The goal of this study was to compare attention and social attention in higher functioning children with ASD (HFASD), who exhibited either low or high levels of ADHD symptoms.

Methods: Four groups of school-aged children participated in this study: 45 with HFASD, 19 with HFASD and ADHD, 36 with ADHD but not ASD, and 39 with typical development. The groups were matched on age (means = 11.3, 10.9, 11.9, 11.7 respectively) but not on IQ (means = 104, 96, 101, 114). As a result, IQ was used as a covariate in all analyses. The groups also differed on parent report of ASD symptoms, as measured by the SCQ and SRS, as well parent report of ADHD symptoms, as measured by the Conners-3 ADHD Total t-scores (70.2, 84.6, 75.2, 49.5). Attention was assessed while children viewed a virtual classroom with 9 targets around a large table (one central target, 3 targets at intermediate positions left and right of center, and one target at an extreme position left and right of center). The task included three 3 minute conditions: 1) a Non-Social (NS) condition, during which children looked at 9 “lollipop” shaped forms around the table, 2) a Social Condition (SC), during which children looked at 9 avatar “peers”, and 3) a High-Demand Social Condition (HDSC), during which the avatars faded away if the child did not fixate them frequently. 

Results:   Analyses revealed diagnostic groups effects in all conditions for average duration of target fixations: NS, F (12, 304) = 2.08, p < .05, eta² = .07, SC, F (12, 304) = 2.21, p < .03, eta² = .07, and the HDSC, F (12, 304) = 2.08, p < .015, eta² = .08.  In the NS and SC, the ADHD group displayed longer fixations to the center target than did the other groups, the TD group displayed longer fixations to the intermediate targets than the other groups, and the HFASD groups displayed shorter fixations to all but the extreme targets relative to the other groups. On the HDSC task, the HFASD-ADHD group displayed a unique pattern of longer duration fixations to the central avatar and much shorter fixations to the intermediate targets than the other groups. 

Conclusions:   The results of this study indicate that individuals with HFASD, HFASD-ADHD and ADHD may all display patterns of attention that distinguish them from their typically developing peers on this task.  In particular, the HFASD groups displayed lower duration, more fleeting attention to social and non-social stimuli relative to the other groups. This tendency was exacerbated in the HFASD-ADHD group in the HDSC task, suggesting this sub-group may be especially vulnerable to increased demands in attention tasks.