title: Early event-related potentials to emotional faces differ for adults with autism spectrum disorder and by serotonin transporter genotype.
abstract: To test differences in neural sensitivity to facial expressions, including expressions with open versus closed mouths, exhibited by (1) adults with autism spectrum disorder (ASD) compared to neurotypical adults, and by (2) short versus long serotonin transporter allele (SLC6A4) carriers.
  
  
  
  Event related potentials (ERPs) to happy, fearful, and neutral expressions were collected from neurotypical adults (n=25) and adults with ASD (n=27)-of whom 32 had short and 13 had homozygous long SLC6A4 alleles.
  
  
  
  In the neurotypical group, we confirmed that the N170, VPP and EPN, but not the P1, were influenced by emotional expressions, and determined the EPN was the earliest component modulated by open mouth. Compared to the neurotypical group, individuals with ASD exhibited differences in EPN amplitude in response to open versus closed mouths and in hemispheric distribution. Across groups, short serotonin transporter allele carriers had reduced P1 amplitude compared to long allele carriers.
  
  
  
  Individuals with ASD exhibited a different pattern of neural response when encoding and recognizing facial expressions at the EPN component. Across groups, SLC6A4 allele type modulated early sensory attention at the P1.
  
  
  
  These results provide insight into the nature of early responses to emotional information according to genetic variation and clinical condition.
authors.affiliation: University of Washington, Department of Psychology, Box 351525, Seattle, WA 98195, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Faja
authors.affiliation: University of Washington, Department of Psychology, Box 351525, Seattle, WA 98195, USA; University of Washington, Department of Psychiatry and Behavioral Sciences, Box 356560, Room BB1644, Seattle, WA 98195, USA.
authors.forename: Geraldine
authors.initials: G
authors.lastname: Dawson
authors.affiliation: Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Aylward
authors.affiliation: University of Washington, Department of Medicine, Division of Medical Genetics, Box 356420, Seattle, WA 98195, USA; University of Washington, Department of Biostatistics, Box 357232, Seattle, WA 98195, USA.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Wijsman
authors.affiliation: University of Washington, Department of Psychiatry and Behavioral Sciences, Box 356560, Room BB1644, Seattle, WA 98195, USA. Electronic address: sjwebb@uw.edu.
authors.forename: Sara Jane
authors.initials: SJ
authors.lastname: Webb
mesh_terms: D000293:Adolescent; D000328:Adult; D000067877:Autism Spectrum Disorder / Q000503:physiopathology*; D016022:Case-Control Studies; D004644:Emotions; D005071:Evoked Potentials; D005149:Facial Expression; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins
keywords: Autism; Electrophysiology; Emotion; Event related potential; SLC6A4; Serotonin