Abstract/Summary

As an information-bearing auditory attribute of sound, pitch plays a crucial role in the perception of speech and music. Studies examining pitch processing in autism spectrum disorder (ASD) have produced equivocal results. To understand this discrepancy from a mechanistic perspective, we used a novel data-driven method, the reverse-correlation paradigm, to explore whether the equivocal findings in ASD have high-level origins in top-down comparisons of internal mental representations of pitch contours. Thirty-two Mandarin-speaking autistic individuals and 32 non-autistic individuals undertook three subtasks testing mental representations of pitch contours in speech, complex tone, and melody, respectively. The results indicate that while the two groups exhibited similar representations of pitch contours across the three conditions, the ASD group showed a significantly higher intra-group variability than the non-ASD group. In addition, the two groups did not differ significantly in internal noise, a measure of the robustness of participant responses to external variability, suggesting that the present findings translate genuinely qualitative differences and similarities between groups in pitch processing. These findings uncover for the first time that pitch patterns in speech and music are mentally represented in a similar manner in autistic and non-autistic individuals, through domain-general top-down mechanisms.