title: The effect of intranasal oxytocin versus placebo treatment on the autonomic responses to human sounds in autism: a single-blind, randomized, placebo-controlled, crossover design study.
abstract: BACKGROUND
  Many individuals with autism spectrum disorders (ASD) have difficulty with verbal communication, which might be due to a lack of spontaneous orientation toward social auditory stimuli. Previous studies have shown that a single dose of oxytocin improves speech comprehension in autism. The primary aim of this study was to investigate whether the orientation behaviors toward human sounds are different for neurotypical (NT) adults and adults with ASD and whether oxytocin has an effect on their orientation behaviors toward human sounds.
  
  
  METHODS
  This was a randomized, placebo-controlled, within-subject, crossover design study of intranasal oxytocin versus placebo in 13 NT adults and 16 adults with ASD. Subjects were randomized to 24 IU intranasal oxytocin or placebo on different days, and they were blind to the treatment. The participants then listened passively to human and non-human affective sounds while their skin conductance responses (SCRs) and the changes in peripheral blood vessel constriction were monitored as an indicator of spontaneous orientation. The monitored data were analyzed by a mixed-design ANOVA.
  
  
  RESULTS
  Oxytocin enhanced the difference between the SCRs to human and non-human sounds in both the NT and ASD groups (F(1,56) = 6.046, p = 0.017). Further correlation coefficient analysis showed significant correlations between this SCR difference and the scores in the autism spectrum quotient 'attention to detail' and 'social skill' subscales and interpersonal reactivity index and social functioning scale in the ASD group. Oxytocin was well tolerated, and no serious adverse effects were reported.
  
  
  CONCLUSIONS
  The difference in SCRs implies that oxytocin nasal spray may enhance orientation behaviors toward human sounds in the presence of other environmental sounds in both ASD and NT adults.
  
  
  BACKGROUND
  UMIN-CTR Clinical Trial, Unique trial number: UMIN000005809.
authors.affiliation: NTT Communication Science Laboratories, NTT Corporation, 3-1, Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan. lin.ifan@lab.ntt.co.jp.
authors.forename: I-Fan
authors.initials: IF
authors.lastname: Lin
authors.forename: Makio
authors.initials: M
authors.lastname: Kashino
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Ohta
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamada
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tani
authors.forename: Hiromi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Chieko
authors.initials: C
authors.lastname: Kanai
authors.forename: Taisei
authors.initials: T
authors.lastname: Ohno
authors.forename: Yuko
authors.initials: Y
authors.lastname: Takayama
authors.forename: Akira
authors.initials: A
authors.lastname: Iwanami
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Kato