title: Overreactive brain responses to sensory stimuli in youth with autism spectrum disorders.
abstract: OBJECTIVE
  Sensory over-responsivity (SOR), defined as a negative response to or avoidance of sensory stimuli, is both highly prevalent and extremely impairing in youth with autism spectrum disorders (ASD), yet little is known about the neurological bases of SOR. This study aimed to examine the functional neural correlates of SOR by comparing brain responses to sensory stimuli in youth with and without ASD.
  
  
  METHODS
  A total of 25 high-functioning youth with ASD and 25 age- and IQ-equivalent typically developing (TD) youth were presented with mildly aversive auditory and visual stimuli during a functional magnetic resonance imaging (fMRI) scan. Parents provided ratings of children's SOR and anxiety symptom severity.
  
  
  RESULTS
  Compared to TD participants, ASD participants displayed greater activation in primary sensory cortical areas as well as amygdala, hippocampus, and orbital-frontal cortex. In both groups, the level of activity in these areas was positively correlated with level of SOR severity as rated by parents, over and above behavioral ratings of anxiety.
  
  
  CONCLUSIONS
  This study demonstrates that youth with ASD show neural hyper-responsivity to sensory stimuli, and that behavioral symptoms of SOR may be related to both heightened responsivity in primary sensory regions as well as areas related to emotion processing and regulation.
authors.affiliation: University of California-Los Angeles (UCLA). Electronic address: shulamite@ucla.edu.
authors.forename: Shulamite A
authors.initials: SA
authors.lastname: Green
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Rudie
authors.forename: Natalie L
authors.initials: NL
authors.lastname: Colich
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Wood
authors.forename: David
authors.initials: D
authors.lastname: Shirinyan
authors.forename: Leanna
authors.initials: L
authors.lastname: Hernandez
authors.forename: Nim
authors.initials: N
authors.lastname: Tottenham
authors.forename: Mirella
authors.initials: M
authors.lastname: Dapretto
authors.forename: Susan Y
authors.initials: SY
authors.lastname: Bookheimer
mesh_terms: D000293:Adolescent; D000679:Amygdala / Q000503:physiopathology; D001007:Anxiety / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000503:physiopathology*; D005260:Female; D059907:Functional Neuroimaging / Q000295:instrumentation / Q000379:methods*; D006624:Hippocampus / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010468:Perceptual Disorders / Q000503:physiopathology; D017397:Prefrontal Cortex / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D012678:Sensation Disorders / Q000503:physiopathology*; D012720:Severity of Illness Index
keywords: amygdala; anxiety; autism spectrum disorders; functional magnetic resonance imaging (fMRI); sensory over-responsivity