This study aimed inhibition mechanisms of auditory processing in the group with autistic features. Thirty-two children (autistic group = 16, typically developing [TD] group = 16) received neuropsychological tests, IQ test and experimental tasks. Both groups showed similar performances except the processing speed index. The results showed that the group with autistic features had less inhibition of return (IOR) than the TD group. However, we did not get a statistically significant group difference in the auditory Go-NoGo task. These results might be attributed to a ceiling effect due to an adjustment failure of a difficulty level instead of showing that the group with autistic features would have intact inhibitory or pitch discriminative function problems. In conclusion, this study showed that the group with autistic features could have an inhibitory processing difficulty in both auditory and visual IOR tasks even when their general cognitive functions are relatively intact. This study presented a possibility that the group with autistic features might have a basic inhibitory function problem, but these findings should be investigated in the further study with enough samples. In addition, we are going to revise the auditory Go-NoGo task and verify the feasibility as a tool to detect ASD in an early stage in the following study.
Keywords: Auditory inhibition of return; auditory Go-NoGo task; autistic features; intelligence; processing speed.