title: Olfactory processing in adults with autism spectrum disorders.
abstract: BACKGROUND
  As evidenced in the DSM-V, autism spectrum disorders (ASD) are often characterized by atypical sensory behavior (hyper- or hypo-reactivity), but very few studies have evaluated olfactory abilities in individuals with ASD.
  
  
  METHODS
  Fifteen adults with ASD and 15 typically developing participants underwent olfactory tests focused on superficial (suprathreshold detection task), perceptual (intensity and pleasantness judgment tasks), and semantic (identification task) odor processing.
  
  
  RESULTS
  In terms of suprathreshold detection performance, decreased discrimination scores and increased bias scores were observed in the ASD group. Furthermore, the participants with ASD exhibited increased intensity judgment scores and impaired scores for pleasantness judgments of unpleasant odorants. Decreased identification performance was also observed in the participants with ASD compared with the typically developing participants. This decrease was partly attributed to a higher number of near misses (a category close to veridical labels) among the participants with ASD than was observed among the typically developing participants.
  
  
  CONCLUSIONS
  The changes in discrimination and bias scores were the result of a high number of false alarms among the participants with ASD, which suggests the adoption of a liberal attitude in their responses. Atypical intensity and pleasantness ratings were associated with hyperresponsiveness and flattened emotional reactions, respectively, which are typical of participants with ASD. The high number of near misses as non-veridical labels suggested that categorical processing is functional in individuals with ASD and could be explained by attention-deficit/hyperactivity disorder. These findings are discussed in terms of dysfunction of the olfactory system.
authors.affiliation: Institut de Neurosciences de la Timone. CNRS & Université Aix-Marseille, Campus Santé Timone 27, Boulevard Jean Moulin, 13385 Marseille cedex 05, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Wicker
authors.affiliation: Integrative, Multisensory, Perception, Action and Cognition Team, Lyon, F-69000 France ; University Lyon 1, Lyon, F-69000 France ; Institut de Médecine Environnementale, Paris, France.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Monfardini
authors.affiliation: INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Olfaction : From Coding to Memory Team, Lyon, F-69000 France ; University Lyon 1, Lyon, F-69000 France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Royet
mesh_terms: D000328:Adult; D000067877:Autism Spectrum Disorder / Q000503:physiopathology* / Q000523:psychology; D004056:Differential Threshold / Q000502:physiology; D004644:Emotions / Q000502:physiology; D005260:Female; D006801:Humans; D006941:Hyperesthesia / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D006987:Hypesthesia / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D008297:Male; D009812:Odorants; D009833:Olfactory Pathways / Q000503:physiopathology*; D055696:Olfactory Perception / Q000502:physiology; D057181:Pleasure; D021641:Recognition, Psychology / Q000502:physiology; D012684:Sensory Thresholds; D055815:Young Adult
keywords: Autism spectrum disorders; Hyperresponsiveness; Identification; Intensity; Olfaction; Pleasantness; Suprathreshold detection