Human cortical encoding of pitch in tonal and non-tonal languages

Junfeng Lu,Claire Tang,Jinsong Wu,Edward F Chang,Yuanning Li

doi:10.1038/s41467-021-21430-x

Abstract

Languages can use a common repertoire of vocal sounds to signify distinct meanings. In tonal languages, such as Mandarin Chinese, pitch contours of syllables distinguish one word from another, whereas in non-tonal languages, such as English, pitch is used to convey intonation. The neural computations underlying language specialization in speech perception are unknown. Here, we use a cross-linguistic approach to address this. Native Mandarin- and English- speaking participants each listened to both Mandarin and English speech, while neural activity was directly recorded from the non-primary auditory cortex. Both groups show language-general coding of speaker-invariant pitch at the single electrode level. At the electrode population level, we find language-specific distribution of cortical tuning parameters in Mandarin speakers only, with enhanced sensitivity to Mandarin tone categories. Our results show that speech perception relies upon a shared cortical auditory feature processing mechanism, which may be tuned to the statistics of a given language.

Highlights

Languages can use a common repertoire of vocal sounds to signify distinct meanings
What kind of information is represented in the superior temporal gyri (STG) is unknown: the acoustic absolute pitch frequency (F0)[16,17], a high-level auditory representation such as speaker-normalized pitch[18], or the abstract linguistic lexical tone identity10? is the encoding of tone-related pitch specialized in Mandarin speakers, compared with those who do not speak a tonal language? Understanding the neurological basis of tone processing can address fundamental questions about how specializations in the human auditory system transform acoustic cues into meaningful linguistic percepts
Cortical neural activity is recorded using high-density electrodes arrays, which are located on the lateral surface of the exposed temporal lobe, whereas participants passively listen to natural, continuous, Mandarin[20], and English speech[21,22]

Summary

Introduction

Languages can use a common repertoire of vocal sounds to signify distinct meanings. In tonal languages, such as Mandarin Chinese, pitch contours of syllables distinguish one word from another, whereas in non-tonal languages, such as English, pitch is used to convey intonation. Native Mandarin- and English- speaking participants each listened to both Mandarin and English speech, while neural activity was directly recorded from the non-primary auditory cortex Both groups show language-general coding of speaker-invariant pitch at the single electrode level. By using the same stimuli for both Mandarin-speaking and English-speaking participants in a cross-linguistic paradigm, our goal is to address how the human brain processes sound pattern variability within and across languages. This provides new fundamental insights into the shared potential mechanisms of auditory processing in tonal and non-tonal languages in humans

Objectives

Results

Conclusion