Speech-specific categorical perception deficit in autism: An Event-Related Potential study of lexical tone processing in Mandarin-speaking children

Abstract

Recent studies reveal that tonal language speakers with autism have enhanced neural sensitivity to pitch changes in nonspeech stimuli but not to lexical tone contrasts in their native language. The present ERP study investigated whether the distinct pitch processing pattern for speech and nonspeech stimuli in autism was due to a speech-specific deficit in categorical perception of lexical tones. A passive oddball paradigm was adopted to examine two groups (16 in the autism group and 15 in the control group) of Chinese children’s Mismatch Responses (MMRs) to equivalent pitch deviations representing within-category and between-category differences in speech and nonspeech contexts. To further examine group-level differences in the MMRs to categorical perception of speech/nonspeech stimuli or lack thereof, neural oscillatory activities at the single trial level were further calculated with the inter-trial phase coherence (ITPC) measure for the theta and beta frequency bands. The MMR and ITPC data from the children with autism showed evidence for lack of categorical perception in the lexical tone condition. In view of the important role of lexical tones in acquiring a tonal language, the results point to the necessity of early intervention for the individuals with autism who show such a speech-specific categorical perception deficit.

Effects of native language experience on Mandarin lexical tone processing in proficient second language learners

“…The new perspective also offers a testable approach for further verification of L2 speech learning models and the study of various contributors to the dynamic process of perceptual warping of acoustic and phonological information in the time course of L2 speech acquisition. The present study builds on previous studies on L2 learners (e.g., Hao, ; Wayland & Guion, ), native speakers (e.g., Wang et al, ; Xi et al, ; K. Yu et al, ; L. Yu et al, ), and nonnative listeners (e.g., Gandour et al, ; Klein, Zatorre, Milner, & Zhao, ; Wong, Parsons, Martinez, & Diehl, ), and we argue that L2 speech acquisition can be conceptualized as a dynamic process of fine‐tuning perceptual sensitivities to the acoustic and phonological information in the target L2 sound system. For the beginning stages, L2 learners may primarily process the L2 speech contrasts in an “acoustic” mode.…”

“…The new perspective also offers a testable approach for further verification of L2 speech learning models and the study of various contributors to the dynamic process of perceptual warping of acoustic and phonological information in the time course of L2 speech acquisition. The present study builds on previous studies on L2 learners (e.g., Hao, 2012;Wayland & Guion, 2004), native speakers (e.g., Wang et al, 2017;Xi et al, 2010;K. Yu et al, 2014;L.…”

“…These were similar to the findings in Xi et al (), which used the same tonal continuum to explore native speakers’ categorical perception of Mandarin lexical tones. Many other studies have also used this tonal continuum to detect native speakers’ categorical perception of Mandarin lexical tones successfully (Wang et al, ; Xi et al, ; K. Yu et al, ; L. Zhang et al, , ).…”

“…Chen, Liu, & Kager, 2016;Huang & Johnson, 2011). Moreover, this tonal continuum has been used successfully to detect native speakers' categorical perception of Mandarin lexical tones in many previous studies (Wang, Wang, Fan, Huang, & Zhang, 2017;Xi et al, 2010;K. Yu et al, 2014;L.…”

“…Furthermore, the pitch features of Tone 3 are complex, and even native speakers could perform poorly when identifying them (e.g., A. Chen, Liu, & Kager, ; Huang & Johnson, ). Moreover, this tonal continuum has been used successfully to detect native speakers’ categorical perception of Mandarin lexical tones in many previous studies (Wang, Wang, Fan, Huang, & Zhang, ; Xi et al, ; K. Yu et al, ; L. Zhang et al, , ). Given the well‐established protocol and findings, we chose the same synthetic tonal continuum from Mandarin Tone 2 to Tone 4 as the test materials.…”