Reduced Sensitivity to Between-Category Information but Preserved Categorical Perception of Lexical Tones in Tone Language Speakers With Congenital Amusia.

Fei Chen,Gang Peng

doi:10.3389/fpsyg.2020.581410

Abstract

Previous studies have shown that for congenital amusics, long-term tone language experience cannot compensate for lexical tone processing difficulties. However, it is still unknown whether such difficulties are merely caused by domain-transferred insensitivity in lower-level acoustic processing and/or by higher-level phonological processing of linguistic pitch as well. The current P300 study links and extends previous studies by uncovering the neurophysiological mechanisms underpinning lexical tone perception difficulties in Mandarin-speaking amusics. Both the behavioral index (d′) and P300 amplitude showed reduced within-category as well as between-category sensitivity among the Mandarin-speaking amusics regardless of the linguistic status of the signal. The results suggest that acoustic pitch processing difficulties in amusics are manifested profoundly and further persist into the higher-level phonological processing that involves the neural processing of different lexical tone categories. Our findings indicate that long-term tone language experience may not compensate for the reduced acoustic pitch processing in tone language speakers with amusia but rather may extend to the neural processing of the phonological information of lexical tones during the attentive stage. However, from both the behavioral and neural evidence, the peakedness scores of the d′ and P300 amplitude were comparable between amusics and controls. It seems that the basic categorical perception (CP) pattern of native lexical tones is preserved in Mandarin-speaking amusics, indicating that they may have normal or near normal long-term categorical memory.

Highlights

As two old and unique products of the human brain, speech and music are present across all cultures (Patel, 2008)
In order to illuminate the level of lexical tone processing difficulties in Mandarin-speaking amusics, this study manipulated tonal category along a pitch continuum to directly dissociate acoustic processing from the phonological processing of lexical tones for native speakers, an approach that was widely adopted in previous event-related potential (ERP) studies (Xi et al, 2010; Zhang et al, 2012; Yu et al, 2014, 2017)
(between-category deviant) as a distinct tone category in both speech and nonspeech contexts. As reflected by both the behavioral and electrophysiological measures, the d′ scores and P300 amplitudes. In both speech and nonspeech contexts were systematically lower in the amusics than the controls when responding to both within‐ and between-category deviants, indicating that both lower-level acoustic processing and higher-level phonological processing were compromised among the tone language speakers with amusia, regardless of the linguistic status of the signal

Summary

Introduction

As two old and unique products of the human brain, speech and music are present across all cultures (Patel, 2008). On the other hand, compared with non-musicians, musicians tend to be more skilled at detecting non-native lexical tone contrasts (e.g., Wong et al, 2007; Lee and Hung, 2008; Chandrasekaran et al, 2009) and even more sensitive to native linguistic tone categories (Tang et al, 2016). These studies imply a two-way transferability of pitch expertise across the domains of music and speech

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