Musicians and tone-language speakers share enhanced brainstem encoding but not perceptual benefits for musical pitch

Behavioral and neurophysiological transfer effects from music experience to language processing are well-established but it is currently unclear whether or not linguistic expertise (e.g., speaking a tone language) benefits music-related processing and its perception. Here, we compare brainstem responses of English-speaking musicians/non-musicians and native speakers of Mandarin Chinese elicited by tuned and detuned musical chords, to determine if enhancements in subcortical processing translate to improvements in the perceptual discrimination of musical pitch. Relative to non-musicians, both musicians and Chinese had stronger brainstem representation of the defining pitches of musical sequences. In contrast, two behavioral pitch discrimination tasks revealed that neither Chinese nor non-musicians were able to discriminate subtle changes in musical pitch with the same accuracy as musicians. Pooled across all listeners, brainstem magnitudes predicted behavioral pitch discrimination performance but considering each group individually, only musicians showed connections between neural and behavioral measures. No brain-behavior correlations were found for tone language speakers or non-musicians. These findings point to a dissociation between subcortical neurophysiological processing and behavioral measures of pitch perception in Chinese listeners. We infer that sensory-level enhancement of musical pitch information yields cognitive-level perceptual benefits only when that information is behaviorally relevant to the listener.     

Relative influence of musical and linguistic experience on early cortical processing of pitch contours

To assess domain specificity of experience-dependent pitch representation we evaluated the mismatch negativity (MMN) and discrimination judgments of English musicians, English nonmusicians, and native Chinese for pitch contours presented in a nonspeech context using a passive oddball paradigm. Stimuli consisted of homologues of Mandarin high rising (T2) and high level (T1) tones, and a linear rising ramp (T2L). One condition involved a between-category contrast (T1/T2), the other, a within-category contrast (T2L/T2). Irrespective of condition, musicians and Chinese showed larger MMN responses than nonmusicians; Chinese larger than musicians. Chinese, however, were less accurate than nonnatives in overt discrimination of T2L and T2. Taken together, these findings suggest that experience-dependent effects to pitch contours are domain-general and not driven by linguistic categories. Yet specific differences in long-term experience in pitch processing between domains (music vs. language) may lead to gradations in cortical plasticity to pitch contours.     

Dialectal differences in hemispheric specialization for Japanese lexical pitch accent

Language experience can alter perceptual abilities and the neural specialization for phonological contrasts. Here we investigated whether dialectal differences in the lexical use of pitch information lead to differences in functional lateralization for pitch processing. We measured cortical hemodynamic responses to pitch pattern changes in native speakers of Standard (Tokyo) Japanese, which has a lexical pitch accent system, and native speakers of ‘accentless’ dialects, which do not have any lexical tonal phenomena. While the Standard Japanese speakers showed left-dominant responses in temporal regions to pitch pattern changes within words, the accentless dialects speakers did not show such left-dominance. Pitch pattern changes within harmonic-complex tones also elicited different brain activation patterns between the two groups. These results indicate that the neural processing of pitch information differs depending on the listener’s native dialect, and that listeners’ linguistic experiences may further affect the processing of pitch changes even for non-linguistic sounds.     

Functional ear (a)symmetry in brainstem neural activity relevant to encoding of voice pitch: a precursor for hemispheric specialization?

Pitch processing is lateralized to the right hemisphere; linguistic pitch is further mediated by left cortical areas. This experiment investigates whether ear asymmetries vary in brainstem representation of pitch depending on linguistic status. Brainstem frequency-following responses (FFRs) were elicited by monaural stimulation of the left and right ear of 15 native speakers of Mandarin Chinese using two synthetic speech stimuli that differ in linguistic status of tone. One represented a native lexical tone (Tone 2: T2); the other, T2′, a nonnative variant in which the pitch contour was a mirror image of T2 with the same starting and ending frequencies. Two 40-ms portions of f₀ contours were selected in order to compare two regions (R1, early; R2 late) differing in pitch acceleration rate and perceptual saliency. In R2, linguistic status effects revealed that T2 exhibited a larger degree of FFR rightward ear asymmetry as reflected in f₀ amplitude relative to T2′. Relative to midline (ear asymmetry = 0), the only ear asymmetry reaching significance was that favoring left ear stimulation elicited by T2′. By left- and right-ear stimulation separately, FFRs elicited by T2 were larger than T2′ in the right ear only. Within T2′, FFRs elicited by the earlier region were larger than the later in both ears. Within T2, no significant differences in FFRS were observed between regions in either ear. Collectively, these findings support the idea that origins of cortical processing preferences for perceptually-salient portions of pitch are rooted in early, preattentive stages of processing in the brainstem.     

ERP correlates of language-specific processing of auditory pitch feedback during self-vocalization

The present study investigated whether the neural correlates for auditory feedback control of vocal pitch can be shaped by tone language experience. Event-related potentials (P2/N1) were recorded from adult native speakers of Mandarin and Cantonese who heard their voice auditory feedback shifted in pitch by −50, −100, −200, or −500 cents when they sustained the vowel sound /u/. Cantonese speakers produced larger P2 amplitudes to −200 or −500 cents stimuli than Mandarin speakers, but this language effect failed to reach significance in the case of −50 or −100 cents. Moreover, Mandarin speakers produced shorter N1 latencies over the left hemisphere than the right hemisphere, whereas Cantonese speakers did not. These findings demonstrate that neural processing of auditory pitch feedback in vocal motor control is subject to language-dependent neural plasticity, suggesting that cortical mechanisms of auditory-vocal integration can be shaped by tone language experience.     

Implicit Association Test (IAT) Studies Investigating Pitch-Shape Audiovisual Cross-modal Associations Across Language Groups

Previous studies have shown that Chinese speakers and non-Chinese speakers exhibit different patterns of cross-modal congruence for the lexical tones of Mandarin Chinese, depending on which features of the pitch they attend to. But is this pattern of language-specific listening a conscious cultural strategy or an automatic processing effect? If automatic, does it also apply when the same pitch contours no longer sound like speech? Implicit Association Tests (IATs) provide an indirect measure of cross-modal association. In a series of IAT studies, conducted with participants with three kinds of language backgrounds (Chinese-dominant bilinguals, Chinese balanced bilinguals, and English speakers with no Chinese experience) we find language-specific congruence effects for Mandarin lexical tones but not for matched sine-wave stimuli. That is, for linguistic stimuli, non-Chinese speakers show advantages for pitch-height congruence (high-pointy, low-curvy); no congruence effects were found for Chinese speakers. For non-linguistic stimuli, all participant groups showed advantages for pitch-height congruence. The present findings suggest that non-lexical tone congruence (high-pointy, low-curvy) is a basic congruence pattern, and the acquisition of a language with lexical tone can alter this perception.     

Enhanced production and perception of musical pitch in tone language speakers

Individuals differ markedly with respect to how well they can imitate pitch through singing and in their ability to perceive pitch differences. We explored whether the use of pitch in one’s native language can account for some of the differences in these abilities. Results from two studies suggest that individuals whose native language is a tone language, in which pitch contributes to word meaning, are better able to imitate (through singing) and perceptually discriminate musical pitch. These findings support the view that language acquisition fine-tunes the processing of critical auditory dimensions in the speech signal and that this fine-tuning can be carried over into nonlinguistic domains.     

The effects of late acquisition of L2 and the consequences of immigration on L1 for semantic and morpho-syntactic language aspects

It has been hypothesized that some aspects of a second language (L2) might be learned easier than others if a language is learned late. On the other hand, non-use might result in a loss of language skills in one's native, i.e. one's first language (L1) (language attrition). To study which, if any, aspects of language are affected by either late acquisition or non-use, long-term German immigrants to the US and English native speakers who are long-term immigrants to Germany as well as two additional control groups of native German speakers were tested with an auditory semantic and morpho-syntactic priming paradigm. German adjectives correctly or incorrectly inflected for gender and semantically associated or not associated with the target noun served as primes. Participants made a lexical decision on the target word. All groups of native German speakers gained from semantically and morpho-syntactically congruent primes. Evidence for language attrition was neither found for semantic nor morpho-syntactic priming effects in the German immigrants. In contrast, English native speakers did not gain from a morpho-syntactic congruent prime, whereas semantic priming effects were similar as for the remaining groups. The present data suggest that the full acquisition of at least some syntactic functions may be restricted to limited periods in life while semantic and morpho-syntactic functions seem to be relatively inured to loss due to non-use.     

A mouse with a roof? effects of phonological neighbors on processing of words in sentences in a non-native language

The architecture of the language processing system for speakers of more than one language remains an intriguing topic of research. A common finding is that speakers of multiple languages are slower at responding to language stimuli in their non-native language (L2) than monolingual speakers. This may simply reflect participants' unfamiliarity with words in the L2, however it may also be the reflection of interference from competing lexical alternatives both across and within the participants' multiple languages. In the current studies (one behavioral, one electrophysiological) we investigate how interference from phonologically similar words within the L2 alone may account for problems in auditory language comprehension in non-native speakers. To this end a cross modal lexical priming (CMLP) paradigm was implemented, which allowed us to look for effects of spoken word primes embedded in sentences on the recognition of target stimuli. Specifically, we investigated whether a word such as mouse, which has a close phonological neighbor, house, would show a modulating effect on recognition of a word semantically related to house but not to mouse (i.e., roof). We hypothesized that L2 speakers, less efficient at categorizing phonemes in their L2 would show a difference in the processing of roof preceded by mouse as compared to roof preceded by another unrelated word, such as lamp, due to a residual co-activation of the phonological neighbor mouse. Furthermore, L1 speakers, highly proficient at recognizing phonemes in their native tongue, should show no such effect. The results of both studies clearly support our hypothesis, indicating that phonological neighbors in the L2 may greatly interfere with L2 word recognition.     

A limit on behavioral plasticity in speech perception

It is well attested that we perceive speech through the filter of our native language: a classic example is that of Japanese listeners who cannot discriminate between the American /l/ and /r/ and identify both as their own /r/ phoneme (Goto, 1971). Studies in the laboratory have shown, however, that perception of non-native speech sounds can be learned through training (Lively et al., 1994). This is consistent with neurophysiological evidence showing considerable experience-dependent plasticity in the brain at the first levels of sensory processing (Edeline and Weinberger, 1993; Merzenich and Sameshima, 1993; Weinberger, 1993; Kraus et al., 1995). Outside of the laboratory, however, the situation seems to differ: we here report a study involving Spanish-Catalan bilingual subjects who have had the best opportunities to learn a new contrast but did not do it. Our study demonstrates a striking lack of behavioral plasticity: early and extensive exposure to a second language is not sufficient to attain the ultimate phonological competence of native speakers.     

Predicting lexical accent perception in native Japanese speakers: An investigation of acoustic pitch sensitivity and working memory

Spoken language perception may be constrained by a listener's cognitive resources, including verbal working memory (WM) capacity and basic auditory perception mechanisms. For Japanese listeners, it is unknown how, or even if, these resources are involved in the processing of pitch accent at the word level. The present study examined the extent to which native Japanese speakers could make correctness judgments on and categorize spoken Japanese words by pitch accent pattern, and how verbal WM capacity and acoustic pitch sensitivity related to perception ability. Results showed that Japanese listeners were highly accurate at judging pitch accent correctness (M = 93%), but that the more cognitively demanding accent categorization task yielded notably lower performance (M = 61%). Of chief interest was the finding that acoustic pitch sensitivity significantly predicted accuracy scores on both perception tasks, while verbal WM had a predictive role only for the categorization of a specific accent pattern. These results indicate first, that task demands greatly influence accuracy and second, that basic cognitive capacities continue to support perception of lexical prosody even in adult listeners.     

The Puzzle of Absolute Pitch

Absolute pitch—the ability to name or produce a note of particular pitch in the absence of a reference note—is generally considered to be extremely rare. However, it has been found that native speakers of two different tone languages—Mandarin and Vietnamese—display a remarkably precise form of absolute pitch in enunciating words. Given these findings, it is proposed that absolute pitch may have evolved as a feature of speech, analogous to other features such as vowel quality. It is also conjectured that tone–language speakers generally acquire this feature during the 1st year of life, in the critical period when infants acquire other features of their native language. For speakers of nontone languages, the acquisition of absolute pitch by rare individuals may be associated with a critical period of unusually long duration, so that it extends to the age at which the child can begin taking music lessons. According to this line of reasoning, the potential for acquiring absolute pitch is universal at birth, and can be realized by giving the infant the opportunity to associate pitches with verbal labels during the 1st year or so of life.     

The KEY to the ROCK: Near-homophony in nonnative visual word recognition

To test the hypothesis that native language (L1) phonology can affect the lexical representations of nonnative words, a visual semantic-relatedness decision task in English was given to native speakers and nonnative speakers whose L1 was Japanese or Arabic. In the critical conditions, the word pair contained a homophone or near-homophone of a semantically associated word, where a near-homophone was defined as a phonological neighbor involving a contrast absent in the speaker’s L1 (e.g., ROCK-LOCK for native speakers of Japanese). In all participant groups, homophones elicited more false positive errors and slower processing than spelling controls. In the Japanese and Arabic groups, near-homophones also induced relatively more false positives and slower processing. The results show that, even when auditory perception is not involved, recognition of nonnative words and, by implication, their lexical representations are affected by the L1 phonology.     

Abstraction and the (Misnamed) Language Familiarity Effect

Talkers are recognized more accurately if they are speaking the listeners’ native language rather than an unfamiliar language. This “language familiarity effect” has been shown not to depend upon comprehension and must instead involve language sound patterns. We further examine the level of sound‐pattern processing involved, by comparing talker recognition in foreign languages versus two varieties of English, by (a) English speakers of one variety, (b) English speakers of the other variety, and (c) non‐native listeners (more familiar with one of the varieties). All listener groups performed better with native than foreign speech, but no effect of language variety appeared: Native listeners discriminated talkers equally well in each, with the native variety never outdoing the other variety, and non‐native listeners discriminated talkers equally poorly in each, irrespective of the variety's familiarity. The results suggest that this talker recognition effect rests not on simple familiarity, but on an abstract level of phonological processing.     

Cognitive strategies in discourse processing: A comparison of Chinese and English speakers

Three experiments tested the hypothesis that, when processing a normative language, individuals tend to adopt the discourse processing strategies that they use in their native language. In a natural language processing task, native speakers of English and Chinese read English passages that were heavily loaded with zero anaphora. Native Chinese speakers found the passages more comprehensible than did native English speakers, presumably because zero anaphora occurs much more often in Chinese than in English. However, in an artificial laboratory task, native Chinese speakers did not find it easier to recover the missing referents than did native English speakers, suggesting that the two groups were equally capable of reference retrieval although they differed in their natural language discourse-processing strategies. These results suggest that the strategies used for processing foreign-language discourse are influenced by those used to process native-language discourse.This research was supported in part by Dean's Small Grants from the Graduate School of the University of Colorado to Liang Tao and United States Army Research Institute Contracts MDA903-90-K-0066 and MDA903-93-K-0010 to the University of Colorado (Alice Healy, Principal Investigator).We thank Barbara Fox, Lise Menn, and Nanfang Jiang for stimulating discussions about this research.An earlier version of this paper was presented at the First International Conference on Chinese Linguistics held in Singapore, 1992.     

/n/-/l/音位合并现象的神经机制：来自MMN的证据

采用ERP技术,比较音位合并者与非音位合并者辨别合并音位/n/-/l/的脑电和行为反应。结果发现,非音位合并者在注意前阶段展现了显著的MMN;而音位合并者没有展现MMN,但在晚期展现了一个显著的负波。行为实验发现,相比于音位合并者,非音位合并者在分辨/n/-/l/时正确率更高,反应时更短。这些结果表明：两组被试区分/n/-/l/的能力在早期自动加工阶段就已经有了显著的差异。方言经验可能降低了音位合并者在听觉感觉加工阶段检测合并音位差异的敏感度。     

Strength of German accent under altered auditory feedback.

Borden's (1979, 1980) hypothesis that speakers with vulnerable speech systems rely more heavily on feedback monitoring than do speakers with less vulnerable systems was investigated. The second language (L2) of a speaker is vulnerable, in comparison with the native language, so alteration to feedback should have a detrimental effect on it, according to this hypothesis. Here, we specifically examined whether altered auditory feedback has an effect on accent strength when speakers speak L2. There were three stages in the experiment. First, 6 German speakers who were fluent in English (their L2) were recorded under six conditions--normal listening, amplified voice level, voice shifted in frequency, delayed auditory feedback, and slowed and accelerated speech rate conditions. Second, judges were trained to rate accent strength. Training was assessed by whether it was successful in separating German speakers speaking English from native English speakers, also speaking English. In the final stage, the judges ranked recordings of each speaker from the first stage as to increasing strength of German accent. The results show that accents were more pronounced under frequency-shifted and delayed auditory feedback conditions than under normal or amplified feedback conditions. Control tests were done to ensure that listeners were judging accent, rather than fluency changes caused by altered auditory feedback. The findings are discussed in terms of Borden's hypothesis and other accounts about why altered auditory feedback disrupts speech control.     

Relative power of harmonics in human frequency-following responses associated with voice pitch in American and Chinese adults

When the fundamental frequency (f0) is removed from a complex stimulus, the pitch of the f0 is still perceived by the listener. Through the use of the scalp-recorded frequency-following response, this study examined the relative contributions of thef0 and its harmonics in pitch processing by systematically manipulating the speech stimulus to remove component frequencies. 12 American and 12 Chinese adults were recruited. There were statistically significant effects of pitch strength and frequency error for the experimental-condition factor. There were significantly larger responses to the harmonics-only conditions than those obtained in the f0-only and control conditions. No statistically significant difference was observed between the two groups of participants. These findings indicate that neural responses associated with individual harmonics dominate the pitch processing in the human brainstem, irrespective of whether the listener's native language is nontonal or tonal.     

Effects of Phonetic Similarity in the Identification of Mandarin Tones

Tonal languages differ in how they use phonetic correlates e.g. average pitch height and pitch direction, for tonal contrasts. Thus, native speakers of a tonal language may need to adjust their attention to familiar or unfamiliar phonetic cues when perceiving non-native tones. On the other hand, speakers of a non-tonal language may need to develop sensitivity to tonal correlates absent from their native system. The current study examines and compares five language groups’ perception of two synthesized Mandarin tones: the high level tone and the high falling tone. It aims to examine how listeners from tonal and non-tonal backgrounds identify and categorize acoustically equidistant pitches varying along two phonetic dimensions: pitch onset and slope. Results reveal “universal” perceptual patterns across groups and also tendencies caused by native tonal systems. Our findings confirm that L1 tonal and prosodic systems affect speakers’ sensitivity to novel perceptual cues and their abilities to discern relevant phonetic differences.