When Do Japanese Children with Autism Spectrum Disorder Comprehend Ambiguous Language Overliterally or Overnonliterally?

Abstract

The present study aimed to clarify whether comprehension of ambiguous sentences in Japanese children with high-functioning autism spectrum disorder (HFASD) varies depending on the degree to which the use of these sentences is conventional. We examined the relationship between comprehension by children with HFASD and college freshmen's assessment of conventionality of usage of these sentences in contexts encouraging literal or nonliteral interpretation. One hundred ninety-four freshmen participated. Children's interpretation preferences were correlated with freshmen's assessments of 9 ambiguous sentences for which previous data showed a significant intergroup difference in interpretation between 45 2nd to 6th graders with HFASD and 45 typically developing (TD) children matched for grade and gender. All the HFASD children fulfilled the criteria for pervasive developmental disorder of DSM-IV-TR, and they ranged in full-scale IQ from 79 to 129 (mean = 97.56, SD = 17.54) and in verbal-IQ from 80 to 136 (mean = 98.87, SD = 17.81). In 6 of these 9 sentences, the interpretation preferred more strongly by children with HFASD than TD children was rated by the freshmen as significantly less strange than the nonpreferred interpretation, regardless of whether it was literal or nonliteral. These results suggest that children with HFASD comprehend ambiguous sentences in accordance with their conventionality as assessed by freshmen. Even when TD children choose a literal interpretation, children with HFASD select the nonliteral one judged more conventional than its literal counterpart. This conformity of children with HFASD to conventional interpretation of ambiguous language seems to account for overliteralness and overnonliteralness.