Exploring Sex Differences in Social Attention in ASD

Background:

Autism Spectrum Conditions (ASC) are estimated to affect males about 3 times more often than females. The majority of previous studies only studied males and only recently have systematic investigations of females with ASC begun (Lai, et al, 2015). Sex differences have been found in aspects of social cognition, such as empathy (Baron-Cohen et al, 2004). However, so far, sex differences not been explored in social motivation (often measured as spontaneous social attention), which has been proposed to also underpin social-communicative impairments.

Objectives:

1. To examine sex differences in social attention across different ages; 2. To investigate whether abnormalities in social attention relate to level of social-communicative impairments and/or level of social adaptive function in males/females.

Methods:

Participants with ASC (199 males, 78 females) and age-matched typically developing (TD) participants (151 males, 71 females) were recruited as part of the EU-AIMS Longitudinal European Autism Project (LEAP). An eye-tracking battery included a set of 6 still images of naturalistic social scenes, each presented for 15 seconds. Eye movements were recorded using Tobii eye-trackers. Areas of Interests (AOIs) focused on the whole face, eye region, mouth, relevant objects (defined by their role in a social interaction) and irrelevant objects. IQ was assessed using the WASI, autism social symptom severity using the parent-report Social Responsiveness Scale (SRS), and level of adaptive functioning using the Vineland Adaptive Behaviour Scale (VABS-III). To test our predictions, 2 (group) x 2(sex) x 3 (age group: child, adolescent, adult) between-subject ANOVAs were used.

Results:

We found a significant effect of group on % gaze time on faces (F(1,487)=8.898, p=.05, r=.02) and a significant group x age interaction (F(2,487)=3.946, p<.05, r = .01). Only TD adults looked longer at faces than adults with ASC, while there were no significant group differences in children and adolescents. In both groups, females looked longer at eyes (F(1,487)=3.729, p=.05, r=.01) than males. However, post-hoc analyses suggested that this pattern was only found during childhood. Gaze time on relevant/ irrelevant objects decreased with age, except for TD females: TD females looked longer at relevant objects than any other group during childhood but shorter during adolescence.

In the ASC group, % gaze on the mouth region was related to higher social-communicative impairments (r =.12, p=.05) and higher levels of adaptive behaviour (VABS composite) (r=.19, p=.01). Among the TD group, longer looking times on faces was linked to lower social-communicative symptoms (r=-.20, p=.05) and higher levels of adaptive functioning (all

Conclusions:

In both groups, females looked longer at eyes than males. Contrary to expectations, these sex differences were only seen during childhood. We also found differential relationships between gaze times on face/ mouth and level of social-communicative symptoms in the ASC and control groups.

Background:

Autism Spectrum Conditions (ASC) are estimated to affect males about 3 to 8 times more often than females. The majority of previous studies only studied males and only recently have systematic investigations of females with ASC begun (Lai, et al, 2015). Sex differences have been found in aspects of social cognition, such as empathy (Baron-Cohen et al, 2004). However, so far, sex differences not been explored in social motivation (often measured as spontaneous social attention), which has been proposed to also underpin social-communicative impairments.

Objectives:

1. To examine sex differences in social attention across different ages; specifically the hypothesis that sex differences become more pronounced in adolescence/adulthood in both groups due to biological (Craig et al., 2007) and/or social factors (Gould & Ashton-Smith, 2011). 2. To investigate whether abnormalities in social attention relate to level of social-communicative impairments and/or level of social adaptive function in males/females.

Methods:

Participants with ASC (199 males, 78 females) and age-matched TD participants (151 males, 71 females) were recruited as part of the EU-AIMS Longitudinal European Autism Project (LEAP). An eye-tracking battery included a set of 6 still images of naturalistic social scenes, each presented for 15 seconds. Eye movements were recorded using Tobii eye-trackers. Areas of Interests (AOIs) focused on the whole face, eye region, mouth, relevant objects (defined by their role in a social interaction) and irrelevant objects. IQ was assessed using the WASI, ASD social symptom severity using the parent-report Social Responsiveness Scale (SRS), and level of adaptive functioning using the Vineland Adaptive Behaviour Scale (VABS-III). To test our predictions, 2 (group) x 2(sex) x 3 (age group: child, adolescent, adult) between-subject ANOVAs were used.

Results:

We found a significant effect of group on % gaze time on faces (F(1,487)=8.898, p=.05, r=.02) and a significant group x age interaction (F(2,487)=3.946, p<.05, r = .01). Only TD adults looked longer at faces than adults with ASD, while there were no significant group differences in children and adolescents. A trend indicated that in both groups females looked longer at eyes (F(1,487)=3.729, p=.05, r=.01) than males. However, posthoc analyses suggested that this pattern was only found during childhood. Gaze time on relevant/ irrelevant objects decreased with age, except for TD females: TD females looked longer at relevant objects than any other group during childhood but shorter during adolescence.

In the ASC group, %gaze on the mouth region was related to higher social-communicative impairments (r =.12, p=.05) and higher levels of adaptive behaviour (VABS composite) (r=.19, p=.01). Among the TD group, longer looking times on faces was linked to lower social-communicative symptoms (r=-.20, p=.05) and higher levels of adaptive functioning (all p=.05),

Conclusions:

We found a trend suggesting that in both groups, females looked longer at eyes than males. Contrary to expectations, these sex differences were only seen during childhood. We also found differential relationships between gaze times on face/ mouth and level of social-communicative symptoms in the ASC and control groups.