Slipped lips: onset asynchrony detection of auditory-visual language in autism.

Background: It has frequently been suggested that individuals with autism spectrum disorder (ASD) have deficits in auditory-visual (AV) sensory integration. Studies of language integration have mostly used non-word syllables presented in congruent and incongruent AV combinations and demonstrated reduced influence of visual speech in individuals with ASD. The aim of our study was to test whether adolescents with high-functioning autism are able to integrate AV information of meaningful, phrase-length language in a task of onset asynchrony detection.
Methods: Participants were 25 adolescents with ASD and 25 typically developing (TD) controls. The stimuli were video clips of complete phrases using simple, commonly occurring words. The clips were digitally manipulated to have the video precede the corresponding audio by 0, 4, 6, 8, 10, 12, or 14 video frames, a range of 0-500ms. Participants were shown the video clips in random order and asked to indicate whether each clip was in-synch or not.
Results: There were no differences between adolescents with ASD and their TD peers in accuracy of onset asynchrony detection at any slip rate.
Conclusion: These data indicate that adolescents with ASD are able to integrate auditory and visual components in a task of onset asynchrony detection using natural, phrase-length language stimuli. We propose that the meaningful nature of the language stimuli in combination with presentation in a non-distracting environment allowed adolescents with autism spectrum disorder to demonstrate preserved accuracy for bi-modal AV integration.