Face Processing and the Broad Autism Phenotype

Background: The Broader Autistic Phenotype (BAP) consists of milder Autistic Spectrum Disorder (ASD) characteristics that occur in some relatives of individuals who have ASD.  The core ASD deficits in communication, socialization, and stereotyped/repetitive behavior have been found to manifest themselves separately in the BAP.  Due to the strong hereditary nature of ASD, the autistic symptomatology  expressed in ASD family members meeting criteria for the BAP can serve as endophenotypes in the study of ASD.  Many of the social problems experienced by people with ASD stem from deficits in facial processing.  Since the BAP consists of mild socialization impairment, face processing has also been studied in ASD relatives, in particular parents, with mixed results of subclinical similarity and dissimilarity to ASD.  Lacking in these face processing studies has been: the examination of typical ASD face processing strategies, as well as measures of both face identity and emotion recognition.   

Objectives: The present study sought to explore the effects of Gender and BAP level on face processing deficits in parents and siblings of individuals with ASD.  We aimed to assess if gender and BAP levels would each account for differences on face processing tasks, as well as if an interaction effect of gender and BAP level could be found.  

Methods: 178 biological parents and siblings, (62 males and 116 females), of individuals with ASD (Mean IQ=109.63) were assessed on: IQ (Wonderlic-WPT-Q), the Let’s Face It Skills Battery (LFI), the Broad Autistic Phenotype Questionnaire (BAPQ), and the Social Communication Questionnaire (SCQ).  Specifically, the LFI evaluates 10 areas of face processing involving subtests of face discrimination, emotion recognition, and non-face objects.  The BAPQ measures an overall BAP level as well as three sub levels of: aloofness, pragmatic language, and rigidity.  All assessments were conducted on-line.   

Results: Results suggest that relatives of ASD children performed at normal levels of face processing.  A 2x2 Manova was conducted with gender and each of the BAP criteria levels.  Gender x Total BAPQ: only gender showed a main effect, on discrimination Pillai’s Trace V=.094, F (5, 136)=2.81, p<.05, no interaction effect.  Gender x Aloofness: the main effect of Gender approached significance, on discrimination Pillai’s Trace V=.074, F(5, 136)=2.18, p=.059, no interaction effect.  Gender x Pragmatic Language: Gender revealed a main effect, on discrimination Pillai’s Trace V=.091, F(5, 136)=2.73, p<.05, no interaction effect.  Gender x Rigidity: both Gender, on discrimination Pillai’s Trace V=.092, F(5, 136)=2.77, p<.05 and Rigidity showed a main effect, on discrimination Pillai’s Trace V=.101, F(5, 136)=3.06, p<.05 and on non-face objects Pillai’s Trace V=.070, F(2, 147)=5.50, p<.01, no interaction effect.  

Conclusions: Evidence suggests that Gender and BAP level differentially effect ASD family members and may contribute to mild social skill difficulties that mimic those difficulties typically found in biological relatives who have an ASD diagnosis.  These findings suggest that effects of BAP level can be distinguished from gender differences.  These results give further insight into the investigation of endophenotypes of ASD as expressed in the BAP, as well as the need to examine the influence of family environment.