Left hemisphere lateralization for lexical and acoustic pitch processing in Cantonese speakers as revealed by mismatch negativity

Native language background affects the perception of duration and pitch

Estonian is a quantity language with both a primary duration cue and a secondary pitch cue, whereas Chinese is a tonal language with a dominant pitch use. Using a mismatch negativity experiment and a behavioral discrimination experiment, we investigated how native language background affects the perception of duration only, pitch only, and duration plus pitch information. Chinese participants perceived duration in Estonian as meaningless acoustic information due to a lack of phonological use of duration in their native language; however, they demonstrated a better pitch discrimination ability than Estonian participants. On the other hand, Estonian participants outperformed Chinese participants in perceiving the non-speech pure tones that resembled the Estonian quantity (i.e., containing both duration and pitch information). Our results indicate that native language background affects the perception of duration and pitch and that such an effect is not specific to processing speech sounds.

Native language advantage in electrical brain responses to speech sound changes in passive and active listening condition

It is not clear whether the brain can detect changes in native and non-native speech sounds in both unattended and attended conditions, but this information would be important to understand the nature of potential native language advantage in speech perception. We recorded event-related potentials (ERPs) for changes in duration and in Chinese lexical tone in a repeated vowel /a/ in native speakers of Finnish and Chinese in passive and active listening conditions. ERP amplitudes reflecting deviance detection (mismatch negativity; MMN and N2b) and attentional shifts towards changes in speech sounds (P3a and P3b) were investigated. In the passive listening condition, duration changes elicited increased amplitude in the MMN latency window for both standard and deviant sounds in the Finnish speakers compared to the Chinese speakers, but no group differences were observed for P3a. In passive listening to lexical tones, P3a was increased in amplitude for both standard and deviant stimuli in Chinese speakers compared to Finnish speakers, but the groups did not differ in MMN. In active listening, both tone and duration changes elicited N2b and P3b, but the groups differed only in pattern of results for the deviant type. The results thus suggest an overall increased sensitivity to native speech sounds, especially in passive listening, while the mechanisms of change detection and attentional shifting seem to work well for both native and non-native speech sounds in the attentive mode.

Perception of grammatical tone in Akan patients with left and right hemisphere brain damage

It remains a matter of debate what roles the left and right hemispheres play in processing speech prosody. Brain lesion studies have demonstrated that lexical tone perception among native speakers of tonal languages is more disrupted in left hemisphere damaged (LHD) individuals than right hemisphere damaged (RHD) individuals. This has been taken to suggest that linguistically-relevant prosodic cues are predominantly left-lateralised, whereas non-linguistic stimuli are predominantly right-lateralised. However, this phenomenon has only been examined in lexical tone, leaving grammatical tone perception unexplored. The aim of this study was twofold: Firstly, to examine how individuals with LHD and RHD perceive grammatical tone, and secondly to compare grammatical tone to non-linguistic tone perception. Therefore, native Akan speakers with LHD, RHD and no-brain damage (NBD) controls were tested in two discrimination tasks that examined linguistic and non-linguistic tone perception. The results showed that while both the individuals with LHD and RHD show impairment in grammatical tone perception, there was a trend of a better performance for the RHD group. Nonetheless, for non-linguistic tone perception, individuals with LHD outperformed the RHD individuals, although both had reduced performance compared to the NBD individuals. A further analysis revealed that the reduced perceptual abilities of both the LHD and RHD groups in grammatical tone perception can be attributed to grammatical problems rather than tone per se. We conclude that there is potentially a bilateral involvement of the two hemispheres in grammatical tone processing, with the left being the dominant hemisphere.

The more the better? Effects of L1 tonal density and typology on the perception of non-native tones

This study investigates the effects of L1 tonal density and typology on naïve listeners' perception of L2 Cantonese tones and pitch-equivalent pure tones. Native speakers of two canonical tone languages (Vietnamese and Mandarin) and a pitch-accent language (Japanese) with varying degrees of tonal density were recruited as listeners in a discrimination task followed by a perceptual assimilation task. Results implied that Mandarin listeners with a sparser tone inventory exhibited significantly better performance than Vietnamese listeners, suggesting that denser tonality in L1 did not facilitate or even interfere with L2 tone perception. Furthermore, both groups of canonical tone listeners processed pitch contours in a domain-general manner, with comparable performance in the perception of lexical tones and pure tones. However, Japanese listeners of the pitch-accent language perceived pure tones better than lexical tones, showing a domain-specific mechanism. These findings suggest that both L1 tonal density and typology may modulate the perception of non-native tones.

Decoding lexical tones and vowels in imagined tonal monosyllables using fNIRS signals

Objective.Speech is a common way of communication. Decoding verbal intent could provide a naturalistic communication way for people with severe motor disabilities. Active brain computer interaction (BCI) speller is one of the most commonly used speech BCIs. To reduce the spelling time of Chinese words, identifying vowels and tones that are embedded in imagined Chinese words is essential. Functional near-infrared spectroscopy (fNIRS) has been widely used in BCI because it is portable, non-invasive, safe, low cost, and has a relatively high spatial resolution.Approach.In this study, an active BCI speller based on fNIRS is presented by covertly rehearsing tonal monosyllables with vowels (i.e. /a/, /i/, /o/, and /u/) and four lexical tones in Mandarin Chinese (i.e. tones 1, 2, 3, and 4) for 10 s.Main results.fNIRS results showed significant differences in the right superior temporal gyrus between imagined vowels with tone 2/3/4 and those with tone 1 (i.e. more activations and stronger connections to other brain regions for imagined vowels with tones 2/3/4 than for those with tone 1). Speech-related areas for tone imagery (i.e. the right hemisphere) provided majority of information for identifying tones, while the left hemisphere had advantages in vowel identification. Having decoded both vowels and tones during the post-stimulus 15 s period, the average classification accuracies exceeded 40% and 70% in multiclass (i.e. four classes) and binary settings, respectively. To spell words more quickly, the time window size for decoding was reduced from 15 s to 2.5 s while the classification accuracies were not significantly reduced.Significance.For the first time, this work demonstrated the possibility of discriminating lexical tones and vowels in imagined tonal syllables simultaneously. In addition, the reduced time window for decoding indicated that the spelling time of Chinese words could be significantly reduced in the fNIRS-based BCIs.

The effects of alphabetic literacy, linguistic-processing demand and tone type on the dichotic listening of lexical tones

Brain lateralization of lexical tone processing remains a matter of debate. In this study we used a dichotic listening paradigm to examine the influences of the knowledge of Jyutping (a romanization writing system which provides explicit Cantonese tone markers), linguistic-processing demand and tone type on the ear preference pattern of native tone processing in Hong Kong Cantonese speakers. While participants with little knowledge of Jyutping showed a previously reported left-ear advantage (LEA), those with a good level of Jyutping expertise exhibited either a right-ear advantage or bilateral processing during lexical tone identification and contour tone discrimination, respectively. As for the effect of linguistic-processing demand, while an LEA was found in acoustic/phonetic perception situations, this advantage disappeared and was replaced by a bilateral pattern in conditions that involved a greater extent of linguistic processing, suggesting an increased involvement of the left hemisphere. Regarding the effect of tone type, both groups showed an LEA in level tone discrimination, but only the Jyutping group demonstrated a bilateral pattern in contour tone discrimination. Overall, knowledge of written codes of tones, greater degree of linguistic processing and contour tone processing seem to influence the brain lateralization of lexical tone processing in native listeners of Cantonese by increasing the recruitment of the left-hemisphere language network.

Learning to Perceive Non-Native Tones via Distributional Training: Effects of Task and Acoustic Cue Weighting

As many distributional learning (DL) studies have shown, adult listeners can achieve discrimination of a difficult non-native contrast after a short repetitive exposure to tokens falling at the extremes of that contrast. Such studies have shown using behavioural methods that a short distributional training can induce perceptual learning of vowel and consonant contrasts. However, much less is known about the neurological correlates of DL, and few studies have examined non-native lexical tone contrasts. Here, Australian-English speakers underwent DL training on a Mandarin tone contrast using behavioural (discrimination, identification) and neural (oddball-EEG) tasks, with listeners hearing either a bimodal or a unimodal distribution. Behavioural results show that listeners learned to discriminate tones after both unimodal and bimodal training; while EEG responses revealed more learning for listeners exposed to the bimodal distribution. Thus, perceptual learning through exposure to brief sound distributions (a) extends to non-native tonal contrasts, and (b) is sensitive to task, phonetic distance, and acoustic cue-weighting. Our findings have implications for models of how auditory and phonetic constraints influence speech learning.

Musicianship Influences Language Effect on Musical Pitch Perception

Given its practical implications, the effect of musicianship on language learning has been vastly researched. Interestingly, growing evidence also suggests that language experience can facilitate music perception. However, the precise nature of this facilitation is not fully understood. To address this research gap, I investigated the interactive effect of language and musicianship on musical pitch and rhythmic perception. Cantonese and English listeners, each divided into musician and non-musician groups, completed the Musical Ear Test and the Raven’s 2 Progressive Matrices. Essentially, an interactive effect of language and musicianship was found on musical pitch but not rhythmic perception. Consistent with previous studies, Cantonese language experience appeared to facilitate musical pitch perception. However, this facilitatory effect was only present among the non-musicians. Among the musicians, Cantonese language experience did not offer any perceptual advantage. The above findings reflect that musicianship influences the effect of language on musical pitch perception. Together with the previous findings, the new findings offer two theoretical implications for the OPERA hypothesis—bi-directionality and mechanisms through which language experience and musicianship interact in different domains.

Early differentiation of memory retrieval processes for newly learned voices and phonemes as indexed by the MMN

Linguistic and vocal information are thought to be differentially processed since the early stages of speech perception, but it remains unclear if this differentiation also concerns automatic processes of memory retrieval. The aim of this ERP study was to compare the automatic retrieval processes for newly learned voices vs phonemes. In a longitudinal experiment, two groups of participants were trained in learning either a new phoneme or a new voice. The MMN elicited by the presentation of the two was measured before and after the training. An enhanced MMN was elicited by the presentation of the learned phoneme, reflecting the activation of an automatic memory retrieval process. Instead, a reduced MMN was elicited by the learned voice, indicating that the voice was perceived as a typical member of the learned voice identity. This suggests that the automatic processes that retrieve linguistic and vocal information are differently affected by experience.

Cantonese advantage on English stress perception: Constraints and neural underpinnings

A prevailing conception of cross-linguistic transfer is that first language experience poses perceptual interference, or at best null effect, on second language speech perception. Surprisingly, a recent study found that Cantonese listeners outperformed English listeners on English stress perception. The present study further evaluated whether segmental variations would constrain the Cantonese advantage on English stress perception. Cantonese and English listeners were tested with both active and passive oddball paradigms in which ERP responses to English stress deviations were elicited. Behaviorally, the Cantonese listeners exhibited a perceptual advantage relative to the English listeners, but this advantage disappeared upon the introduction of segmental variations. Neurophysiologically, segmental variations diminished the P3b amplitudes of the Cantonese but not the English listeners. Collectively, results suggest that segmental variations constrain the Cantonese advantage on English stress perception.

Acoustics versus linguistics? Context is Part and Parcel to lateralized processing of the parts and parcels of speech

The purpose of this review is to provide an accessible exploration of key considerations of lateralization in speech and non-speech perception using clear and defined language. From these considerations, the primary arguments for each side of the linguistics versus acoustics debate are outlined and explored in context of emerging integrative theories. This theoretical approach entails a perspective that linguistic and acoustic features differentially contribute to leftward bias, depending on the given context. Such contextual factors include stimulus parameters and variables of stimulus presentation (e.g., noise/silence and monaural/binaural) and variances in individuals (sex, handedness, age, and behavioural ability). Discussion of these factors and their interaction is also aimed towards providing an outline of variables that require consideration when developing and reviewing methodology of acoustic and linguistic processing laterality studies. Thus, there are three primary aims in the present paper: (1) to provide the reader with key theoretical perspectives from the acoustics/linguistics debate and a synthesis of the two viewpoints, (2) to highlight key caveats for generalizing findings regarding predominant models of speech laterality, and (3) to provide a practical guide for methodological control using predominant behavioural measures (i.e., gap detection and dichotic listening tasks) and/or neurophysiological measures (i.e., mismatch negativity) of speech laterality.

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

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.

Different languages rely on different vocal sounds to convey meaning. Here the authors show that language-general coding of pitch occurs in the non-primary auditory cortex for both tonal (Mandarin Chinese) and non-tonal (English) languages, with some language specificity on the population level.

Visual mismatch negativity elicited by semantic violations in visual words

The remarkable rapidity and effortlessness of speech perception and word reading by skilled listeners or readers suggest implicit or automatic mechanisms underlying language processing. In speech perception, the implicit mechanisms are reflected by the auditory mismatch negativity (MMN) response, suggesting that phonemic, lexical, semantic, and syntactic information are automatically and rapidly processed in the absence of focused attention. In visual word reading, implicit orthographic and lexical processing are reflected by visual mismatch negativity (vMMN), the visual counterpart of auditory MMN. The semantic processing of spoken words is reflected by MMN. This study investigated whether semantic processing is also reflected by vMMN. For this purpose, visual Chinese words belonging to different semantic categories (color, taste, and action) were presented to participants in oddball paradigms. A set of words belonging to the same semantic category was frequently presented as standards; a word belonging to a different semantic category was presented sporadically as deviant. Participants were instructed to perform a visual cross-change detection task and ignore the words. Significant vMMN was elicited in Experiments 1 to 3, in which the deviant word carried a semantic radical that overtly indicated the word's semantic category information. The vMMNs were most prominent around 260 ms after word onset, were parieto-occipital distributed, and were significantly left-hemisphere lateralized, suggesting rapid semantic processing of the visual words' category-related information. No significant vMMN was elicited in Experiment 4, in which the deviant word did not carry any semantic radicals. Thus, the semantic radical, which has a high frequency of occurrence because it is carried by many words, may be critical for the elicitation of vMMN.

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

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.

One-week phonemic training rebuilds the memory traces of merged phonemes in merged speakers

The phonemic merger is a unique phenomenon which is referred to as acoustically very different phonemes are recognized as the same phoneme. In our previous study, we demonstrated that the merged speakers had lost the ability to discriminate the merged phonemes pre-attentively, as revealed by their failure in mismatch negativity (MMN) elicitation in the oddball stream of the merged phonemes /n/-/l/. In this study, we investigated the recovery of the discrimination ability via phonemic training and found that the merged speakers regained the ability of discriminating merged phonemes pre-attentively, after a 7-day /n/-/l/ phonemic training, as revealed by the reactivation of MMN brain response to the /n/-/l/ phoneme categories. Our finding indicates that separate memory traces of merged phonemes could be rebuilt during the training process.

Lateralization of Auditory Processing of Silbo Gomero

Left-hemispheric language dominance is a well-known characteristic of the human language system. However, it has been shown that leftward language lateralization decreases dramatically when people communicate using whistles. Whistled languages present a transformation of a spoken language into whistles, facilitating communication over great distances. In order to investigate the laterality of Silbo Gomero, a form of whistled Spanish, we used a vocal and a whistled dichotic listening task in a sample of 75 healthy Spanish speakers. Both individuals that were able to whistle and to understand Silbo Gomero and a non-whistling control group showed a clear right-ear advantage for vocal dichotic listening. For whistled dichotic listening, the control group did not show any hemispheric asymmetries. In contrast, the whistlers’ group showed a right-ear advantage for whistled stimuli. This right-ear advantage was, however, smaller compared to the right-ear advantage found for vocal dichotic listening. In line with a previous study on language lateralization of whistled Turkish, these findings suggest that whistled language processing is associated with a decrease in left and a relative increase in right hemispheric processing. This shows that bihemispheric processing of whistled language stimuli occurs independent of language.

Influence of different acoustic cues in L1 lexical tone on the perception of L2 lexical stress using principal component analysis: an ERP study

Previous studies have widely explored the prosodic transfer from L1 to L2 during speech perception across stress languages. However, few if any studies have investigated the transfer from L1 tonal language to L2 stress language and the relative roles of different acoustic cues underlying the transfer. Therefore, the current study was conducted to compare the perception of English lexical stress between Mandarin and Cantonese speakers who learn English as a foreign language. The event-related potential measurements and the principal component analysis were conducted for the two groups to explore the roles of different acoustic cues in the perception of English speech. The results demonstrated that compared with the Mandarin group, the Cantonese speakers relied more on pitch information and the reliance holds even when all the three cues varied simultaneously. Therefore, it was concluded that prosodic transfer from L1 lexical tone to L2 lexical stress occurred at the acoustic level, and the native linguistic background shaped the manner how speakers perceived the L2 speech.

Acute separate and combined effects of cannabinoid and nicotinic receptor agonists on MMN-indexed auditory deviance detection in healthy humans

The high prevalence of concomitant cannabis and nicotine use has implications for sensory and cognitive processing. While nicotine tends to enhance function in these domains, cannabis use has been associated with both sensory and cognitive impairments, though the underlying mechanisms are unclear. Additionally, the interaction of the nicotinic (nAChR) and cannabinoid (CB₁) receptor systems has received limited study in terms of sensory/cognitive processes. This study involving healthy volunteers assessed the acute separate and combined effects of nabilone (a CB₁ agonist) and nicotine on sensory processing as assessed by auditory deviance detection and indexed by the mismatch negativity (MMN) event-related potential. It was hypothesized that nabilone would impair auditory discriminability as shown by diminished MMN amplitudes, but not when administered in combination with nicotine. 20 male non-smokers and non-cannabis-users were assessed using a 5-stimulus 'optimal' multi-feature MMN paradigm within a randomized, placebo controlled design (placebo; nabilone [0.5 mg]; nicotine [6 mg]; and nicotine + nabilone). Treatment effects were region- and deviant-dependent. At the temporal regions (mastoid sites), MMN was reduced by nabilone and nicotine separately, whereas co-administration resulted in no impairment. At the frontal region, MMN was enhanced by co-administration of nicotine and nabilone, with no MMN effects being found with separate treatment. These neural effects have relevance for sensory/cognitive processes influenced by separate and simultaneous use of cannabis and tobacco and may have treatment implications for disorders associated with sensory dysfunction and impairments in endocannabinoid and nicotinic cholinergic neurotransmission.

The Effects of Acoustic Variation on the Perception of Lexical Tone in Cantonese-Speaking Congenital Amusics

Purpose Congenital amusia is an inborn neurogenetic disorder of fine-grained pitch processing. This study attempted to pinpoint the impairment mechanism of speech processing in tonal language speakers with amusia. We designed a series of perception tasks aiming at selectively probing low-level pitch processing and relatively high-level phonological processing of lexical tones, with an aim to illuminate the deficiency mechanism underlying tone perception in amusia. Method Sixteen Cantonese-speaking amusics and 16 matched controls were tested on the effects of acoustic (talker/syllable) variations on the identification and discrimination of Cantonese tones in two conditions. In the low-variation condition, tones were always associated with the same talker or syllable; in the high-variation condition, tones were associated with either different talkers (with the syllable controlled) or different syllables (with the talker controlled). Results Largely similar results were obtained in talker and syllable variation conditions. Amusics exhibited overall poorer performance than controls in tone identification. Although amusics also demonstrated poorer performance in tone discrimination, the group difference was more obvious in low-variation conditions, where more acoustic constancy was provided. Besides, controls exhibited a greater increase in discrimination sensitivity from high- to low-variation conditions, implying a stronger benefit of acoustic constancy. Conclusions The findings suggested that amusics' lexical tone perception abilities, in terms of both low-level pitch processing and high-level phonological processing, as measured in low- and high-variation conditions, are impaired. Importantly, amusics were more impaired in taking advantage of low acoustic variation contexts and thus less efficiently sharpened their perception of tones when perceptual anchors in talker/syllable were provided, suggesting a possible "anchoring deficit" in congenital amusia. Supplemental Material https://doi.org/10.23641/asha.7616555.

Brain Processing (Auditory Event-Related Potential) of Stressed Versus Unstressed Words in Thai Speech

This study investigated the effect of the stressed word in Thai language on auditory event-related potential (aERP) in unattended conditions. We presented 30 healthy participants with monosyllabic Thai words consisting of either stressed or unstressed words. We instructed them not to attend to the sound stimuli, but rather to watch and memorize the contents of a silent natural documentary without subtitles. The two listening conditions consisted of 20% deviant stimuli (70 stressed and 70 unstressed words, respectively) and 80% standard stimuli (other 280 unstressed words) presented pseudorandomly and binaurally via a pair of earphones. Participants' aERPs from the two conditions were evaluated by the mismatch negativity (MMN) component of aERP. The mismatch negativity amplitudes in the stressed word condition were significantly higher than those in the unstressed word condition, especially in frontal and left fronto-central brain areas. Therefore, these data show the role of the frontal and left fronto-central brain regions in auditory preattentive processing of stressed word perception among native Thai speakers. This is the first study demonstration that stressed meaningful monosyllable words in tonal language facilitate word perception in this preattentive stage. This result has implications for developing clinical tests evaluating preattentive speech perception.

The Functional Neuroanatomy of Lexical Tone Perception: An Activation Likelihood Estimation Meta-Analysis

In tonal language such as Chinese, lexical tone serves as a phonemic feature in determining word meaning. Meanwhile, it is close to prosody in terms of suprasegmental pitch variations and larynx-based articulation. The important yet mixed nature of lexical tone has evoked considerable studies, but no consensus has been reached on its functional neuroanatomy. This meta-analysis aimed at uncovering the neural network of lexical tone perception in comparison with that of phoneme and prosody in a unified framework. Independent Activation Likelihood Estimation meta-analyses were conducted for different linguistic elements: lexical tone by native tonal language speakers, lexical tone by non-tonal language speakers, phoneme, word-level prosody, and sentence-level prosody. Results showed that lexical tone and prosody studies demonstrated more extensive activations in the right than the left auditory cortex, whereas the opposite pattern was found for phoneme studies. Only tonal language speakers consistently recruited the left anterior superior temporal gyrus (STG) for processing lexical tone, an area implicated in phoneme processing and word-form recognition. Moreover, an anterior-lateral to posterior-medial gradient of activation as a function of element timescale was revealed in the right STG, in which the activation for lexical tone lied between that for phoneme and that for prosody. Another topological pattern was shown on the left precentral gyrus (preCG), with the activation for lexical tone overlapped with that for prosody but ventral to that for phoneme. These findings provide evidence that the neural network for lexical tone perception is hybrid with those for phoneme and prosody. That is, resembling prosody, lexical tone perception, regardless of language experience, involved right auditory cortex, with activation localized between sites engaged by phonemic and prosodic processing, suggesting a hierarchical organization of representations in the right auditory cortex. For tonal language speakers, lexical tone additionally engaged the left STG lexical mapping network, consistent with the phonemic representation. Similarly, when processing lexical tone, only tonal language speakers engaged the left preCG site implicated in prosody perception, consistent with tonal language speakers having stronger articulatory representations for lexical tone in the laryngeal sensorimotor network. A dynamic dual-stream model for lexical tone perception was proposed and discussed.

Normal pre-attentive and impaired attentive processing of lexical tones in Cantonese-speaking congenital amusics

The neural underpinnings of congenital amusia, an innate neurogenetic disorder of musical pitch processing, are not well understood. Previous studies suggest that amusia primarily impairs attentive processing (P300) of small pitch deviations in music, leaving pre-attentive pitch processing (mismatch negativity or MMN) more or less intact. However, it remains unknown whether the same neuro-dynamic mechanism of deficiency underlies pitch processing in speech, where amusics also often show impairment behaviorally. The current study examined how lexical tones are processed in pre-attentive (MMN) and attentive (P300) conditions in 24 Cantonese-speaking amusics and 24 matched controls. At the pre-attentive level, Cantonese-speaking amusics exhibited normal MMN responses to lexical tone changes, even for tone pairs with small pitch differences (mid level vs. low level tone; high rising vs. low rising tone). However, at the attentive level, amusics exhibited reduced P3a amplitude for all tone pairs, and further reduced P3b amplitude for tone pairs with small pitch differences. These results suggest that the amusic brain detects tone changes normally pre-attentively, but shows impairment in consciously detecting the same tone differences. Consistent with previous findings in nonspeech pitch processing, this finding provides support for a domain-general neuro-dynamic mechanism of deficient attentive pitch processing in amusia.

Are lexical tones musical? Native language's influence on neural response to pitch in different domains

Language experience shapes musical and speech pitch processing. We investigated whether speaking a lexical tone language natively modulates neural processing of pitch in language and music as well as their correlation. We tested tone language (Mandarin Chinese), and non-tone language (Dutch) listeners in a passive oddball paradigm measuring mismatch negativity (MMN) for (i) Chinese lexical tones and (ii) three-note musical melodies with similar pitch contours. For lexical tones, Chinese listeners showed a later MMN peak than the non-tone language listeners, whereas for MMN amplitude there were no significant differences between groups. Dutch participants also showed a late discriminative negativity (LDN). In the music condition two MMNs, corresponding to the two notes that differed between the standard and the deviant were found for both groups, and an LDN were found for both the Dutch and the Chinese listeners. The music MMNs were significantly right lateralized. Importantly, significant correlations were found between the lexical tone and the music MMNs for the Dutch but not the Chinese participants. The results suggest that speaking a tone language natively does not necessarily enhance neural responses to pitch either in language or in music, but that it does change the nature of neural pitch processing: non-tone language speakers appear to perceive lexical tones as musical, whereas for tone language speakers, lexical tones and music may activate different neural networks. Neural resources seem to be assigned differently for the lexical tones and for musical melodies, presumably depending on the presence or absence of long-term phonological memory traces.

Auditory to Visual Cross-Modal Adaptation for Emotion: Psychophysical and Neural Correlates

Adaptation is fundamental in sensory processing and has been studied extensively within the same sensory modality. However, little is known about adaptation across sensory modalities, especially in the context of high-level processing, such as the perception of emotion. Previous studies have shown that prolonged exposure to a face exhibiting one emotion, such as happiness, leads to contrastive biases in the perception of subsequently presented faces toward the opposite emotion, such as sadness. Such work has shown the importance of adaptation in calibrating face perception based on prior visual exposure. In the present study, we showed for the first time that emotion-laden sounds, like laughter, adapt the visual perception of emotional faces, that is, subjects more frequently perceived faces as sad after listening to a happy sound. Furthermore, via electroencephalography recordings and event-related potential analysis, we showed that there was a neural correlate underlying the perceptual bias: There was an attenuated response occurring at ∼ 400 ms to happy test faces and a quickened response to sad test faces, after exposure to a happy sound. Our results provide the first direct evidence for a behavioral cross-modal adaptation effect on the perception of facial emotion, and its neural correlate.

Exploring the neural correlates of lexical stress perception in english among Chinese-English bilingual children with autism spectrum disorder: An ERP study

Previous studies found that individuals with autism spectrum disorder (ASD) were less sensitive to the variations of lexical stress in their native language than typically developing controls. However, no study has been conducted to explore the perception of lexical stress in the second language among individuals with ASD. Using ERPs (event-related potentials) measurement with an oddball paradigm, the current study examined and compared the neural responses by Chinese-English bilingual children with ASD and typically developing controls in the processing of English lexical stress. The results showed that when compared with typically developing controls, children with ASD manifested reduced MMN (mismatch negativity) amplitude at the left temporal-parietal and parietal sites, indicating that they were less sensitive to lexical stress. However, a more negative MMN response was found for ASD group than for typically developing group at the right central-parietal, temporal-parietal, and temporal sites. In addition, the right hemisphere was more activated than the left hemisphere for ASD group, which might be derived from the reversed asymmetry of brain activation for individuals with ASD when processing language-related stimuli.

Deficits of congenital amusia beyond pitch: Evidence from impaired categorical perception of vowels in Cantonese-speaking congenital amusics

Congenital amusia is a lifelong disorder of fine-grained pitch processing in music and speech. However, it remains unclear whether amusia is a pitch-specific deficit, or whether it affects frequency/spectral processing more broadly, such as the perception of formant frequency in vowels, apart from pitch. In this study, in order to illuminate the scope of the deficits, we compared the performance of 15 Cantonese-speaking amusics and 15 matched controls on the categorical perception of sound continua in four stimulus contexts: lexical tone, pure tone, vowel, and voice onset time (VOT). Whereas lexical tone, pure tone and vowel continua rely on frequency/spectral processing, the VOT continuum depends on duration/temporal processing. We found that the amusic participants performed similarly to controls in all stimulus contexts in the identification, in terms of the across-category boundary location and boundary width. However, the amusic participants performed systematically worse than controls in discriminating stimuli in those three contexts that depended on frequency/spectral processing (lexical tone, pure tone and vowel), whereas they performed normally when discriminating duration differences (VOT). These findings suggest that the deficit of amusia is probably not pitch specific, but affects frequency/spectral processing more broadly. Furthermore, there appeared to be differences in the impairment of frequency/spectral discrimination in speech and nonspeech contexts. The amusic participants 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 across the board regardless of between- and within-category discriminations in nonspeech contexts (pure tone), suggesting impaired general auditory processing. These differences imply that the frequency/spectral-processing deficit might be manifested differentially in speech and nonspeech contexts in amusics—it is manifested as a deficit of higher-level phonological processing in speech sounds, and as a deficit of lower-level auditory processing in nonspeech sounds.

Pitch shape modulates the time course of tone vs pitch-accent identification in Mandarin Chinese

In Mandarin Chinese pitch is used to express both lexical meanings via tones and sentence-level meanings via pitch-accents raising the question of which information is processed first. While research with meaningful sentence materials suggested a general processing advantage of tone over pitch-accents, research on pure tones and nonce speech in pre-attentive processing found that the f0-shape led to timing and site processing differences. The current study reconciles these results by exploring whether the tone advantage found in meaningful speech materials is modulated by the f0-shape by establishing via a gating paradigm the relative timing of tone and pitch-accent identification. Target words containing static (T1) and dynamic (T2, T4) tones were embedded into meaningful sentences and were divided into 50 ms gates which were added incrementally either from the left- or right-edge of the target word. Results showed that dynamic targets had either a tone or pitch-accent advantage contingent on the direction of gate processing. In contrast, for static T1 targets, tone and pitch-accent were identified simultaneously regardless of the direction of gate processing. Altogether, these results indicate that the f0-shape, as defined by pitch dimensions of f0 and pitch range, mediates the timing of tone and pitch-accent identification in meaningful speech supporting highly interactive models of speech perception.

Neural bases of congenital amusia in tonal language speakers

Congenital amusia is a lifelong neurodevelopmental disorder of fine-grained pitch processing. In this fMRI study, we examined the neural bases of congenial amusia in speakers of a tonal language - Cantonese. Previous studies on non-tonal language speakers suggest that the neural deficits of congenital amusia lie in the music-selective neural circuitry in the right inferior frontal gyrus (IFG). However, it is unclear whether this finding can generalize to congenital amusics in tonal languages. Tonal language experience has been reported to shape the neural processing of pitch, which raises the question of how tonal language experience affects the neural bases of congenital amusia. To investigate this question, we examined the neural circuitries sub-serving the processing of relative pitch interval in pitch-matched Cantonese level tone and musical stimuli in 11 Cantonese-speaking amusics and 11 musically intact controls. Cantonese-speaking amusics exhibited abnormal brain activities in a widely distributed neural network during the processing of lexical tone and musical stimuli. Whereas the controls exhibited significant activation in the right superior temporal gyrus (STG) in the lexical tone condition and in the cerebellum regardless of the lexical tone and music conditions, no activation was found in the amusics in those regions, which likely reflects a dysfunctional neural mechanism of relative pitch processing in the amusics. Furthermore, the amusics showed abnormally strong activation of the right middle frontal gyrus and precuneus when the pitch stimuli were repeated, which presumably reflect deficits of attending to repeated pitch stimuli or encoding them into working memory. No significant group difference was found in the right IFG in either the whole-brain analysis or region-of-interest analysis. These findings imply that the neural deficits in tonal language speakers might differ from those in non-tonal language speakers, and overlap partly with the neural circuitries of lexical tone processing (e.g. right STG).

Maturation of Brain Regions Related to the Default Mode Network during Adolescence Facilitates Narrative Comprehension

Objectives

Although the Default Mode Network (DMN) has been examined extensively in adults, developmental characteristics of this network during childhood are not fully understood.

Methods

In this longitudinal study, we characterized the developmental changes in the DMN in fifteen children who were each scanned three times during a narrative comprehension task using magnetic resonance imaging.

Results

Despite similar brain-activation patterns along developmental ages 5 to 18 years when listening to stories, increased, widely distributed deactivation of the DMN was observed in children between the ages of 11 and 18 years. Our findings suggest that changes occurring with increased age, primarily brain maturation and cognitive development drive deactivation of the DMN, which in turn might facilitate attendance to the task.

Conclusions

The interpretation of our results is as a possible reference for the typical course of deactivation of the DMN and to explain the impaired patterns in this neural network associated with different language-related pathologies.

Emotional and Interactional Prosody across Animal Communication Systems: A Comparative Approach to the Emergence of Language

Across a wide range of animal taxa, prosodic modulation of the voice can express emotional information and is used to coordinate vocal interactions between multiple individuals. Within a comparative approach to animal communication systems, I hypothesize that the ability for emotional and interactional prosody (EIP) paved the way for the evolution of linguistic prosody - and perhaps also of music, continuing to play a vital role in the acquisition of language. In support of this hypothesis, I review three research fields: (i) empirical studies on the adaptive value of EIP in non-human primates, mammals, songbirds, anurans, and insects; (ii) the beneficial effects of EIP in scaffolding language learning and social development in human infants; (iii) the cognitive relationship between linguistic prosody and the ability for music, which has often been identified as the evolutionary precursor of language.

The time course of lexical competition during spoken word recognition in Mandarin Chinese: an event-related potential study

The present study investigated the effect of lexical competition on the time course of spoken word recognition in Mandarin Chinese using a unimodal auditory priming paradigm. Two kinds of competitive environments were designed. In one session (session 1), only the unrelated and the identical primes were presented before the target words. In the other session (session 2), besides the two conditions in session 1, the target words were also preceded by the cohort primes that have the same initial syllables as the targets. Behavioral results showed an inhibitory effect of the cohort competitors (primes) on target word recognition. The event-related potential results showed that the spoken word recognition processing in the middle and late latency windows is modulated by whether the phonologically related competitors are presented or not. Specifically, preceding activation of the competitors can induce direct competitions between multiple candidate words and lead to increased processing difficulties, primarily at the word disambiguation and selection stage during Mandarin Chinese spoken word recognition. The current study provided both behavioral and electrophysiological evidences for the lexical competition effect among the candidate words during spoken word recognition.

Lexical tonal discrimination in Zapotec children. A study of the theta rhythm

BACKGROUND

Zapotec is a language used mainly in the state of Oaxaca in Mexico of tonal characteristic; homophone words with difference in fundamental frequency with different meanings. Our objective was to analyze changes in the electroencephalographic (EEG) theta rhythm during word discrimination of lexical tonal bi-syllabic homophone word samples of Zapotec.

METHODS

We employed electroencephalography analysis during lexical tonal discrimination in 12 healthy subjects 9-16 years of age.

RESULTS

We observed an increase in theta relative power between lexical discrimination and at rest eyes-open state in right temporal site. We also observed several significant intra- and inter-hemispheric correlations in several scalp sites, mainly in left fronto-temporal and right temporal areas when subjects were performing lexical discrimination.

CONCLUSIONS

Our data suggest more engagement of neural networks of the right hemisphere are involved in Zapotec language discrimination.

Functionally integrated neural processing of linguistic and talker information: An event-related fMRI and ERP study

Speech signals contain information of both linguistic content and a talker's voice. Conventionally, linguistic and talker processing are thought to be mediated by distinct neural systems in the left and right hemispheres respectively, but there is growing evidence that linguistic and talker processing interact in many ways. Previous studies suggest that talker-related vocal tract changes are processed integrally with phonetic changes in the bilateral posterior superior temporal gyrus/superior temporal sulcus (STG/STS), because the vocal tract parameter influences the perception of phonetic information. It is yet unclear whether the bilateral STG is also activated by the integral processing of another parameter - pitch, which influences the perception of lexical tone information and is related to talker differences in tone languages. In this study, we conducted separate functional magnetic resonance imaging (fMRI) and event-related potential (ERP) experiments to examine the spatial and temporal loci of interactions of lexical tone and talker-related pitch processing in Cantonese. We found that the STG was activated bilaterally during the processing of talker changes when listeners attended to lexical tone changes in the stimuli and during the processing of lexical tone changes when listeners attended to talker changes, suggesting that lexical tone and talker processing are functionally integrated in the bilateral STG. It extends the previous study, providing evidence for a general neural mechanism of integral phonetic and talker processing in the bilateral STG. The ERP results show interactions of lexical tone and talker processing 500-800ms after auditory word onset (a simultaneous posterior P3b and a frontal negativity). Moreover, there is some asymmetry in the interaction, such that unattended talker changes affect linguistic processing more than vice versa, which may be related to the ambiguity that talker changes cause in speech perception and/or attention bias to talker changes. Our findings have implications for understanding the neural encoding of linguistic and talker information.

Processing Cantonese lexical tones: Evidence from oddball paradigms

Two event-related potential (ERP) experiments were conducted to investigate whether Cantonese lexical tones are processed with general auditory perception mechanisms and/or a special speech module. Two tonal features (f0 direction and f0 height deviation) were manipulated to reflect acoustic processing, and the contrast between syllables and hums was used to reveal the involvement of a speech module. Experiment 1 adopted a passive oddball paradigm to study a relatively early stage of tonal processing. Mismatch negativity (MMN) and novelty P3 (P3a) were modulated by the interaction between tonal feature and stimulus type. Similar interactions were found for N2 and P3 in Experiment 2, where more in-depth tonal processing was examined with an active oddball paradigm. Moreover, detecting tonal deviants of syllables elicited N1 and P2 that were not found in hum detection. Together, these findings suggest that the processing of lexical tone relies on both acoustic and linguistic processes from the early stage. Another noteworthy finding is the absence of brain lateralization in both experiments, which challenges the use of a lateralization pattern as evidence for processing lexical tones through a special speech module.

Modulation of pre-attentive spectro-temporal feature processing in the human auditory system by HD-tDCS

The present study examined the functional lateralization of the human auditory cortex (AC) for pre-attentive spectro-temporal feature processing. By using high-definition transcranial direct current stimulation (HD-tDCS), we systematically modulated neuronal activity of the bilateral AC. We assessed the influence of anodal and cathodal HD-tDCS delivered over the left or right AC on auditory mismatch negativity (MMN) in response to temporal as well as spectral deviants in 12 healthy subjects. The results showed that MMN to temporal deviants was significantly enhanced by anodal HD-tDCS applied over the left AC only. Our data indicate a left hemispheric dominance for the pre-attentive processing of low-level temporal information.

Cortical pitch response components index stimulus onset/offset and dynamic features of pitch contours

Voice pitch is an important information-bearing component of language that is subject to experience dependent plasticity at both early cortical and subcortical stages of processing. We have already demonstrated that pitch onset component (Na) of the cortical pitch response (CPR) is sensitive to flat pitch and its salience … CPR responses from Chinese listeners were elicited by three citation forms varying in pitch acceleration and duration. Results showed that the pitch onset component (Na) was invariant to changes in acceleration. In contrast, Na–Pb and Pb–Nb showed a systematic decrease in the interpeak latency and decrease in amplitude with increase in pitch acceleration that followed the time course of pitch change across the three stimuli. A strong correlation with pitch acceleration was observed for these two components only – a putative index of pitch-relevant neural activity associated with the more rapidly-changing portions of the pitch contour. Pc–Nc marks unambiguously the stimulus offset … and their functional roles as related to sensory and cognitive properties of the stimulus. [Corrected]