Sex Differences in Neural Response to Emotional Faces in Children with ASD

Poster Presentation
Saturday, May 4, 2019: 11:30 AM-1:30 PM
Room: 710 (Palais des congres de Montreal)
L. H. Singer, T. Winkelman, M. R. Altschuler, E. Hamo, E. Jarzabek, J. Wolf, B. Lewis, A. Naples and J. McPartland, Child Study Center, Yale University School of Medicine, New Haven, CT

Previous studies indicate that males and females with autism spectrum disorder (ASD) exhibit different social behaviors. School-aged girls with ASD tend to be more socially motivated and mimic peers in social interactions more frequently than boys with ASD (Sedgewick et al., 2016; Dean et al, 2016). Event related potential (ERP) recordings show promise in clarifying the neural basis of sex differences in ASD. One study found that in response to static, neutral faces, girls with ASD showed weaker neural activity than boys at the N170, an ERP marker of face perception (Coffman et al., 2015). However, a general population study indicates that autism-like traits are associated with poorer performance on emotion recognition tests in boys, but not girls (Kothari, 2013). While the body of ERP research focuses on response to static faces, the current study is unique both in that it utilizes dynamic faces and that the faces exhibit emotional expressions.


The study aims to assess potential sex differences in N170 and P100 amplitudes in response to dynamic, emotional faces in typically developing (TD) children and children with ASD.


The current study included 30 children with ASD (24 male, 6 female) and 24 TD children (14 male, 10 female) matched on age (ASD: M = 13.78 , SD = 2.83; TD: M = 12.83, SD = 2.94) and IQ (ASD: M = 107.38, SD = 28.56; TD: M = 109.75, SD = 11.31). Participants were presented with photorealistic faces with neutral facial expressions. When a participant fixated directly on a face, as measured by eye-tracking, the facial expression changed to happy or fearful. Data were filtered, re-referenced, epoched from -100 to 500 ms, baseline corrected, artifact detected, and averaged for each stimulus (happy and fear). ERP latencies and amplitudes were extracted from left and right occipitotemporal electrodes. Amplitude difference scores were calculated as fear minus happy condition.


A two-way ANOVA indicated a significant interaction between diagnosis and sex, F(1, 63) = 5.57, p = .022, η2 = 0.10, with a medium effect size, on amplitude difference. Post-hoc independent samples T-tests were performed with Bonferroni correction (.050/2: p < .025). Among the ASD group but not the TD group, males showed significantly attenuated N170 amplitudes in the left hemisphere in response to emotional faces (M = -.41, SD =1.91) relative to females (M = 2.37, SD = 3.58), t(28) = -2.66, p = .013.


These findings highlight sex differences in neural activity when viewing emotionally salient stimuli that may underlie sex differences between social difficulties in children with ASD, which may help to identify new, specific therapeutic targets for individuals with autism of both sexes. Analyses in progress examine relationships among sex differences in neural response and clinical phenotype.