Categorical perception of lexical tones in mandarin-speaking congenital amusics

Abstract

Previous research suggests that within Mandarin-speaking congenital amusics, only a subgroup has behavioral lexical tone perception impairments (tone agnosia), whereas the rest of amusics do not. The purpose of the current study was to investigate the categorical nature of lexical tone perception in Mandarin-speaking amusics with and without behavioral lexical tone deficits. Three groups of listeners (controls, pure amusics, and amusics with tone agnosia) participated in tone identification and discrimination tasks. Indexes of the categorical perception (CP) of a physical continuum of fundamental frequencies ranging from a rising to level tone were measured. Specifically, the stimulus durations were manipulated at 100 and 200 ms. For both stimulus durations, all groups exhibited similar categorical boundaries. The pure amusics showed sharp identification slopes and significantly peaked discrimination functions similar to those of normal controls. However, such essential characteristics for the CP of lexical tones were not observed in amusics with tone agnosia. An enlarged step-size from 20 to 35 Hz was not able to produce any discrimination peaks in tone agnosics either. The current study revealed that only amusics with tone agnosia showed a lack of categorical tone perception, while the pure amusics demonstrated typical CP of lexical tones, indicating that the deficit of pitch processing in music does not necessarily result in the deficit in the CP of lexical tones. The different performance between congenital amusics with and without tone agnosia provides a new perspective on the proposition of the relationship between music and speech perception.

Tracing the Trajectory of Sensory Plasticity across Different Stages of Speech Learning in Adulthood

“…To calculate the category boundary and the slope of the identification curve, we fitted a logistic regression model on the tone identification function on an individual subject basis, consistent with prior work [59, 69], with the following formula: $$y=1/(1+\mathit{exp}(-b\ast (x-c)))$$…”

Neural bases of congenital amusia in tonal language speakers

“…For instance, Nan et al (2010) found that Mandarin-speaking amusics performed worse than musically intact controls in the identification and discrimination of Mandarin tones, though there was individual variation in the severity of lexical tone impairment. Furthermore, there is some evidence that the deficiency in tonal language speakers is not confined to auditory pitch processing, but prevails to higher-level phonological processing, impeding the categorical perception of lexical tone (Jiang et al 2012b; Huang et al 2015a). All these findings suggest that the musical pitch deficit prevails to pitch processing in language.…”

The effect of syllable variation on the perception of lexical tones in Cantonese-speaking amusics

“…While the aforementioned studies consistently pointed out that the impoverished lexical tone perception in tonal and nontonal language speakers with amusia is due to the domaingeneral pitch deficit, some studies have suggested that highlevel phonological processing of lexical tones might be impaired in native tonal language speakers with amusia. For instance, several studies provided evidence that categorical perception of native tones in tonal language speakers with amusia is impaired [19]- [21]. In contrast to the controls, Mandarin-speaking amusics showed no benefit for betweencategory tone discriminations, suggesting the absence or impairment of categorical perception of lexical tones, though one study found subgroup differences among Mandarinspeaking amusics [18], [19].…”

“…For instance, several studies provided evidence that categorical perception of native tones in tonal language speakers with amusia is impaired [19]- [21]. In contrast to the controls, Mandarin-speaking amusics showed no benefit for betweencategory tone discriminations, suggesting the absence or impairment of categorical perception of lexical tones, though one study found subgroup differences among Mandarinspeaking amusics [18], [19]. In another study, Zhang et al found that Cantonese-speaking amusics exhibited less benefit in between-category discriminations than controls in speech contexts (lexical tone and vowel), suggesting reduced categorical perception; on the other hand, they performed inferiorly compared to controls regardless of between-and within-category discriminations in nonspeech contexts (pure tone), suggesting impaired auditory pitch processing [21].…”