title: Infant social attention: an endophenotype of ASD-related traits?
abstract: As a neurodevelopmental disorder, symptoms of ASD likely emerge from a complex interaction between preexisting genetic vulnerabilities and the child's environment. One way to understand causal paths to ASD is to identify dimensional ASD-related traits that vary in the general population and that predispose individuals with other risk factors toward ASD. Moving beyond behavioral traits to explore underlying neurocognitive processes may further constrain the underlying genetics. Endophenotypes are quantitative, heritable, trait-related differences that are generally assessed with laboratory-based methods, can be identified in the general population, and may be more closely tied to particular causal chains that have a more restricted set of genetic roots. The most fruitful endophenotypes may be those observed in infancy, prior to the emergence of behavioral symptoms that they are hypothesized to cause. Social motivation is an ASD-related trait that is highly heritable. In this study, we investigate whether infant endophenotypes of social attention relate to familial risk for lower social motivation in the general population.
  
  
  
  We examined whether infant social attention (measured using habituation, EEG power, and event-related potential tasks previously used in infants/toddlers with ASD) varies quantitatively with parental social motivation in 117 six-month-old and 106 twelve-month-old typically developing infants assessed cross-sectionally. To assess heritable aspects of social motivation, primary caregiver biological parents completed two self-report measures of social avoidance and discomfort that have shown high heritability in previous work.
  
  
  
  Parents with higher social discomfort and avoidance had infants who showed shorter looks to faces but not objects; reduced theta power during naturalistic social attention; and smaller P400 responses to faces versus objects.
  
  
  
  Early reductions in social attention are continuously related to lower parental social motivation. Alterations in social attention may be infant endophenotypes of social motivation traits related to ASD.
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck, University of London, London, UK.
authors.forename: Emily J H
authors.identifier: 0000-0001-5747-9540
authors.initials: EJ
authors.lastname: Jones
authors.affiliation: Center on Human Development and Disability, University of Washington, Seattle, WA, USA.
authors.forename: Kaitlin
authors.initials: K
authors.lastname: Venema
authors.affiliation: Center on Human Development and Disability, University of Washington, Seattle, WA, USA.|Department of School Psychology, University of Washington, Seattle, WA, USA.
authors.forename: Rachel K
authors.initials: RK
authors.lastname: Earl
authors.affiliation: Center on Human Development and Disability, University of Washington, Seattle, WA, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Lowy
authors.affiliation: Department of Psychiatry & Behavioral Sciences, University of Washington, Seattle, WA, USA.|Center for Child Health, Behavior & Development, Seattle Children's Research Institute, Seattle, WA, USA.
authors.forename: Sara J
authors.initials: SJ
authors.lastname: Webb
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D000067877:Autism Spectrum Disorder / Q000503:physiopathology*; D058256:Brain Waves / Q000502:physiology*; D003430:Cross-Sectional Studies; D058068:Endophenotypes; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D018730:Infant Behavior / Q000502:physiology*; D008297:Male; D009042:Motivation / Q000502:physiology; D010290:Parents; D012919:Social Behavior; D012938:Social Perception
keywords: Autism spectrum disorders; endophenotype; infancy; social attention