title: Effect of propranolol on facial scanning in autism spectrum disorder: a preliminary investigation.
abstract: BACKGROUND
  Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social communication impairments and restricted, repetitive behaviors. Whereas current pharmacological interventions for ASD focus primarily on psychiatric symptoms, including agitation and obsessive behaviors, few agents target core symptomatology. It has been previously hypothesized that abnormalities in facial scanning, such as reduced eye contact or increased mouth fixation, contribute to social communication deficits in ASD. In addition, previous reports have suggested elevated stress and anxiety in ASD, symptoms that are believed to impact facial scanning patterns.
  
  
  OBJECTIVE
  The present pilot study sought to explore the effects of pharmacological intervention via propranolol, a nonselective β-adrenergic antagonist and known anxiolytic, on facial scanning in ASD. Specifically, we wished to determine whether there is an increase in eye contact and a decrease in mouth fixation with administration of propranolol.
  
  
  METHODS
  A sample of 14 participants with ASD and 14 matched controls participated in two study sessions in which propranolol and placebo were administered in a counterbalanced, double-blinded manner. At each session, ocular fixation data were collected during presentation of video stimuli of 16 human faces. Fixation time on the eye, nose, and mouth regions of the face stimuli was analyzed.
  
  
  RESULTS
  The baseline fixation patterns for the ASD and control groups did not significantly differ; however, administration of propranolol was associated with a significant reduction in mouth fixation for the ASD group. Additionally, mouth fixation was positively related to nonverbal communication impairment in the ASD group.
  
  
  CONCLUSIONS
  Although eye fixation in ASD appears typical in the present study, the effect of propranolol in reducing mouth fixation suggests an important focus for further research. Future studies are needed to better characterize the relationship between stress and anxiety and facial scanning in ASD, as well as the effects of pharmacological intervention.
authors.affiliation: a Interdisciplinary Neuroscience Program , University of Missouri , Columbia , MO , USA.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Zamzow
authors.forename: Shawn E
authors.initials: SE
authors.lastname: Christ
authors.forename: Sanjida S
authors.initials: SS
authors.lastname: Saklayen
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Moffitt
authors.forename: Kimberly E
authors.initials: KE
authors.lastname: Bodner
authors.forename: Katherine F
authors.initials: KF
authors.lastname: Higgins
authors.forename: David Q
authors.initials: DQ
authors.lastname: Beversdorf
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D002659:Child Development Disorders, Pervasive / Q000188:drug therapy* / Q000503:physiopathology; D004311:Double-Blind Method; D005145:Face; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010865:Pilot Projects; D011433:Propranolol / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012938:Social Perception; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000319:Adrenergic beta-Antagonists; D011433:Propranolol
keywords: Autism; Eye tracking; Facial scanning; Noradrenergic; Propranolol