RESUMO
Autism spectrum disorder (ASD) comprises a multi-dimensional set of quantitative behavioral traits expressed along a continuum in autistic and neurotypical individuals. ASD diagnosis-a dichotomous trait-is known to be highly heritable and has been used as the phenotype for most ASD genetic studies. But less is known about the heritability of autism spectrum quantitative traits, especially in adults, an important prerequisite for gene discovery. We sought to measure the heritability of many autism-relevant quantitative traits in adults high in autism spectrum traits and their extended family members. Among adults high in autism spectrum traits (n = 158) and their extended family members (n = 245), we calculated univariate and bivariate heritability estimates for 19 autism spectrum traits across several behavioral domains. We found nearly all tested autism spectrum quantitative traits to be significantly heritable (h2 = 0.24-0.79), including overall ASD traits, restricted repetitive behaviors, broader autism phenotype traits, social anxiety, and executive functioning. The degree of shared heritability varied based on method and specificity of the assessment measure. We found high shared heritability for the self-report measures and for most of the informant-report measures, with little shared heritability among performance-based cognition tasks. These findings suggest that many autism spectrum quantitative traits would be good, feasible candidates for future genetics studies, allowing for an increase in the power of autism gene discovery. Our findings suggest that the degree of shared heritability between traits depends on the assessment method (self-report vs. informant-report vs. performance-based tasks), as well as trait-specificity. LAY SUMMARY: We found that the scores from questionnaires and tasks measuring different types of behaviors and abilities related to autism spectrum disorder (ASD) were heritable (strongly influenced by gene variants passed down through a family) among autistic adults and their family members. These findings mean that these scores can be used in future studies interested in identifying specific genes and gene variants that are associated with different behaviors and abilities related with ASD.
Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Adulto , Transtorno do Espectro Autista/genética , Função Executiva , Humanos , Fenótipo , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Learning through social observation (i.e., watching other people interact) lays the foundation for later social skills and social cognition. However, social situations are often complex, and humans are only capable of attending to one aspect of a scene at a time. How do people choose where to allocate their visual resources when viewing complex social scenarios? For typically developing (TD) individuals, faces are often given priority. Depending upon context, however, it may be more useful to attend to other aspects of the environment, such as hands, tools, or background objects. Previous studies reported reduced face looking in individuals with autism spectrum disorder (ASD), but modulation of visual attention in response to contextual differences (e.g., according to social richness, or the presence/absence of communicative behaviors between two people) has only briefly been explored. In this study, we used eye-tracking technology to test the extent to which ASD adults and TD adults use social context to guide their gaze behavior. METHODS: Fifty-five adults participated (28 with ASD). The location and duration of participants' gaze were recorded while they watched a series of naturalistic social videos. Half of the videos depicted two people engaging in non-verbal communication (rich social scenes) while playing with toys. The other half depicted two people playing with toys separately, not interacting with each other (lean social scenes). RESULTS: ASD and TD adults both increased their attention to faces in communicative contexts (rich social scenes) as compared to non-communicative contexts (lean social scenes). However, TD adults increased their attention to faces significantly more when watching two people communicate than did ASD adults, who increased their attention to a lesser degree. Further analysis revealed that ASD adults persisted in looking at hands and toys, even when observing two people communicate in a rich social scene. CONCLUSIONS: Diminished gaze to faces when observing two people communicating may lead to fewer opportunities for social learning and subsequent reductions in social knowledge. Naturalistic measures of contextual modulation could help identify areas of need for individuals learning about the social world and could become treatment targets to improve everyday social learning.
Assuntos
Adaptação Psicológica/fisiologia , Atenção/fisiologia , Transtorno do Espectro Autista/fisiopatologia , Transtorno de Comunicação Social/fisiopatologia , Percepção Social , Percepção Visual/fisiologia , Adulto , Transtorno do Espectro Autista/complicações , Medições dos Movimentos Oculares , Reconhecimento Facial/fisiologia , Feminino , Fixação Ocular/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Transtorno de Comunicação Social/etiologia , Adulto JovemRESUMO
There is increasing recognition that adults with autism spectrum disorder (ASD) would benefit from treatment to improve social functioning, a key factor in adults' overall quality of life. However, the various behavioral components of social functioning (i.e., categories of behaviors underlying social functioning), including social motivation, social anxiety, social cognition, and social skills, have not all been assessed together in any sample of adults with ASD, making it difficult to know the relative levels of impairment in these various categories, the relationships among these categories, or promising targets for treatments. We hypothesized there would be significant correlations among measures within the same category, but fewer correlations of measures between categories, indicating the heterogeneity of impairments in adults with ASD. Twenty-nine adults with ASD without co-occurring intellectual disability completed multiple assessments measuring social motivation, social anxiety, social cognition, and social skills, as well as measures of overall ASD symptom levels and community functioning. Results revealed significant positive correlations among measures within most categories; positive correlations between measures of social motivation and all other categories, except for social cognition; as well as positive cross-domain correlations between measures of anxiety and ASD phenotype; measures of social skills and community functioning; and measures of social skills and ASD phenotype. Further studies are warranted to determine causal relationships among these behavioral categories, across developmental stages. However, the lack of correlations between many categories suggests the potential importance of multidimensional treatments that target the particular components of social functioning most in need of improvement in individuals. Autism Res 2018, 11: 488-502. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: The goal of this study was to measure behaviors that contribute to social functioning difficulties in adults with ASD, with the ultimate goal of guiding treatment development. We found that motivation to interact with others was significantly related to social anxiety and social skill. Our results suggest that motivation may be important to target in treatment, and that treatments should be tailored to the areas most in need of improvement in each individual.