Neural and Attentional Indices of Joint Attention in ASD
Objectives: We developed an interactive neuroscience experiment to assess: (1) brain activity during simulated joint attention tasks in individuals with ASD; (2) visual attention and its relationship to brain activity during an interaction; and (3) the relationship of brain activity and attention to social function.
Methods: EEG was recorded from adolescents with ASD (N=33, mean age=14.15, mean IQ=112) and TD controls (N=31, mean age=14.4, mean IQ=110) using a 128 electrode net. ET was simultaneously recorded at 500hz and enabled the experiment to respond to the participants’ gaze, simulating a social interaction. When participants looked at an onscreen face, it responded by returning gaze to the participant or looking to a treasure chest target in one of four corners of the screen. If the participant maintained eye contact with the onscreen face, they were rewarded with the face reciprocally smiling. If they followed gaze to the treasure chest, they were rewarded by the chest opening and showing a jewel. ERPs were time-locked to joint attention bids from the onscreen face (averted gaze or eye contact) and feedback (smiling faces, jewels).
Results: Preliminary analyses indicated that individuals with ASD displayed differential patterns of brain activity and attention during interactions. Individuals with ASD were slower to look to cued targets [t=-2.6, p=.008] and exhibited larger P100s to non-social feedback [F(41)=5.79, p=.021], suggesting differential patterns of anticipation. Temporally subsequent brain activity revealed that both groups displayed greater response to social feedback at the P200 [F(41)=8.58, p=.006] and P300 [F(41)=13.558, p=.001]. This activity was correlated with social function across groups such that reduced neural sensitivity to social reward predicted poorer social function on the Social Responsiveness Scale [r=.37, p=.033] and the Child Behavior Checklist [r=.44, p=.009]. Analyses in progress incorporate pupil dilation and oscillatory activity.
Conclusions: In an interactive social context, individuals with ASD exhibited atypical patterns of anticipation and response as measured by both brain activity and eye-tracking. Overall, both groups showed similar patterns of brain activity in response to social and non-social feedback, suggesting preserved basic mechanisms across groups. However, variability in phenotype predicted differential brain response, reflecting the importance of individual differences across groups. These findings demonstrate that interactive neuroscience approaches occupy a fruitful middle ground between passive experimental measures and unconstrained clinical contexts, and reveal meaningful relationships between clinical heterogeneity and well-specified markers of brain activity.
See more of: Brain Function (fMRI, fcMRI, MRS, EEG, ERP, MEG)