Rhythm's gonna get you: Regular meter facilitates semantic sentence processing

Integrated sentence-level speech perception evokes strengthened language networks and facilitates early speech development

Natural poetic speeches (i.e., proverbs, nursery rhymes, and commercial ads) with strong prosodic regularities are easily memorized by children and the harmonious acoustic patterns are suggested to facilitate their integrated sentence processing. Do children have specific neural pathways for perceiving such poetic utterances, and does their speech development benefit from it? We recorded the task-induced hemodynamic changes of 94 children aged 2 to 12 years using functional near-infrared spectroscopy (fNIRS) while they listened to poetic and non-poetic natural sentences. Seventy-three adult as controls were recruited to investigate the developmental specificity of children group. The results indicated that poetic sentences perceiving is a highly integrated process featured by a lower brain workload in both groups. However, an early activated large-scale network was induced only in the child group, coordinated by hubs for connectivity diversity. Additionally, poetic speeches evoked activation in the phonological encoding regions in the children's group rather than adult controls which decreases with children's ages. The neural responses to poetic speeches were positively linked to children's speech communication performance, especially the fluency and semantic aspects. These results reveal children's neural sensitivity to integrated speech perception which facilitate early speech development by strengthening more sophisticated language networks and the perception-production circuit.

The Effect of Prosodic Timing Structure on Unison Production in People With Aphasia

PURPOSE

Unison production is a common aphasia treatment technique in which the clinician and the person with aphasia (PWA) produce phrases aloud together. It can be implemented using a typical "conversational," syntax-influenced prosodic timing structure, or with a "metrical," beat-based timing structure, but to date no study has directly compared these two approaches. This study compared the effects of metrical versus conversational prosodic timing during unison production on the (a) accuracy of participants' spoken output and (b) timing alignment of participants' productions with the stimuli.

METHOD

PWAs and controls listened to conversationally timed and metrically timed sentences and repeated them in unison with audio recordings. Productions were transcribed and scored in two ways: (a) Accuracy was calculated as the percentage of correctly produced syllables, and (b) timing alignment was determined by extracting the voice onset moment of identical target syllables in the unison stimuli and participant productions in both conditions and comparing the corresponding time points.

RESULTS

Metrical timing yielded a greater number of accurate syllables in both groups, with larger effect in PWAs than in controls. Both groups exhibited more anticipatory, less variable timing when speaking along with metrical stimuli, though evidence of such prediction was also present in the conversational condition.

CONCLUSIONS

Results suggest that unison production works via entrainment-a process that utilizes prediction to guide synchronous production of spoken output. Metrically regular stimuli may facilitate this process as they are more rhythmically predictable. Future work will examine key behavioral variables that predict benefit from unison production and metrical timing.

The use of lexical semantics for processing face-masked speech in monolinguals and bilinguals

Face masks impede visual and acoustic cues that help make speech processing and language comprehension more efficient. Many studies report this phenomenon, but few examined how listeners utilize semantic information to overcome the challenges posed by face masks. Fewer still investigated this impact on bilinguals' processing of face-masked speech [Smiljanic, Keerstock, Meemann, and Ransom, S. M. (2021). J. Acoust. Soc. Am. 149(6), 4013-4023; Truong, Beck, and Weber (2021). J. Acoust. Soc. Am. 149(1), 142-144]. Therefore, this study aims to determine how monolingual and bilingual listeners use semantic information to compensate for the loss of visual and acoustic information when the speaker is wearing a mask. A lexical priming experiment tested how monolingual listeners and early-acquiring simultaneous bilingual listeners responded to video of English word pairs. The prime-target pairs were either strongly related, weakly related, or unrelated and were both either masked or unmasked. Analyses of reaction time results showed an overall effect of masking in both groups and an effect of semantic association strength on processing masked and unmasked speech. However, speaker groups were not different; subsequent analyses of difference values showed no effect of semantic context. These results illustrate the limited role of word-level semantic information on processing in adverse listening conditions. Results are discussed in light of semantic processing at the sentence level.

Alternation preferences affect focus marking in German and English differently

This study investigates the interplay between alternation preferences and corrective focus marking in the production of German and English speakers. Both languages prefer an alternation of strong and weak, and both use pitch accenting to indicate focus structure. The objective of the study is to determine whether the preference for rhythmic alternation can account for variations in the prosodic marking of focus. Contrary to previous claims, the results obtained from three production experiments indicate that rhythmic adjustment strategies do occur during focus marking. However, despite the similarities between the two languages, they employ different strategies when alternation and focus marking work in opposite directions. German speakers often employ a melodic alternation of high and low by realizing the first of two adjacent focus accents with a rising pitch accent (L^*H), while English speakers frequently omit the first focus accent in clash contexts. This finding is further supported by a second experiment that investigates pitch accent clashes in rhythm rule contexts under various focus environments. The findings suggest that the preference for alternation can influence the prosodic marking of focus and contributes to variation in the realization of information-structure categories.

Rhythm Perception, Speaking Rate Entrainment, and Conversational Quality: A Mediated Model

PURPOSE

Acoustic-prosodic entrainment, defined as the tendency for individuals to modify their speech behaviors to more closely align with the behaviors of their conversation partner, plays an important role in successful interaction. From a mechanistic perspective, acoustic-prosodic entrainment is, by its very nature, a rhythmic activity. Accordingly, it is highly plausible that an individual's rhythm perception abilities play a role in their ability to successfully entrain. Here, we examine the impact of rhythm perception in speaking rate entrainment and subsequent conversational quality.

METHOD

A round-robin paradigm was used to collect 90 dialogues from neurotypical adults. Additional assessments determined participants' rhythm perception abilities, social competence, and partner familiarity (i.e., whether the conversation partners knew each other prior to the interaction. Mediation analysis was used to examine the relationships between rhythm perception scores, speaking rate entrainment (using a measure of static local synchrony), and a measure of conversational success (i.e., conversational quality) based on third-party listener observations. Findings were compared to the same analysis with three additional predictive factors: participant gender, partner familiarity, and social competence.

RESULTS

Results revealed a relationship between rhythm perception and speaking rate entrainment. In unfamiliar conversation partners, there was a relationship between speaking rate entrainment and conversational quality. The relationships between entrainment and each of the three additional factors (i.e., gender, partner familiarity, and social competence) were nonsignificant.

CONCLUSIONS

In unfamiliar conversation partners, better rhythm perception abilities were indicative of increased conversational quality mediated by higher levels of speaking rate entrainment. These results support theoretical postulations specifying rhythm perception abilities as a component of acoustic-prosodic entrainment, which, in turn, facilitates conversational success. Knowledge of this relationship contributes to the development of a causal framework for considering a mechanism by which rhythm perception deficits in clinical populations may impact conversational success.

How poetry evokes emotions

Poetry evokes emotions. It does so, according to the theory we present, from three sorts of simulation. They each can prompt emotions, which are communications both within the brain and among people. First, models of a poem's semantic contents can evoke emotions as do models that occur in depictions of all kinds, from novels to perceptions. Second, mimetic simulations of prosodic cues, such as meter, rhythm, and rhyme, yield particular emotional states. Third, people's simulations of themselves enable them to know that they are engaged with a poem, and an aesthetic emotion can occur as a result. The three simulations predict certain sorts of emotion, e.g., prosodic cues can evoke basic emotions of happiness, sadness, anger, and anxiety. Empirical evidence corroborates the theory, which we relate to other accounts of poetic emotions.

In Time with the Beat: Entrainment in Patients with Phonological Impairment, Apraxia of Speech, and Parkinson's Disease

In the present study, we investigated if individuals with neurogenic speech sound impairments of three types, Parkinson’s dysarthria, apraxia of speech, and aphasic phonological impairment, accommodate their speech to the natural speech rhythm of an auditory model, and if so, whether the effect is more significant after hearing metrically regular sentences as compared to those with an irregular pattern. This question builds on theories of rhythmic entrainment, assuming that sensorimotor predictions of upcoming events allow humans to synchronize their actions with an external rhythm. To investigate entrainment effects, we conducted a sentence completion task relating participants’ response latencies to the spoken rhythm of the prime heard immediately before. A further research question was if the perceived rhythm interacts with the rhythm of the participants’ own productions, i.e., the trochaic or iambic stress pattern of disyllabic target words. For a control group of healthy speakers, our study revealed evidence for entrainment when trochaic target words were preceded by regularly stressed prime sentences. Persons with Parkinson’s dysarthria showed a pattern similar to that of the healthy individuals. For the patient groups with apraxia of speech and with phonological impairment, considerably longer response latencies with differing patterns were observed. Trochaic target words were initiated with significantly shorter latencies, whereas the metrical regularity of prime sentences had no consistent impact on response latencies and did not interact with the stress pattern of the target words to be produced. The absence of an entrainment in these patients may be explained by the more severe difficulties in initiating speech at all. We discuss the results in terms of clinical implications for diagnostics and therapy in neurogenic speech disorders.

Rhythmic subvocalization: An eye-tracking study on silent poetry reading

The present study investigates effects of conventionally metered and rhymed poetry on eyemovements in silent reading. Readers saw MRRL poems (i.e., metrically regular, rhymed language) in two layouts. In poem layout, verse endings coincided with line breaks. In prose layout verse endings could be mid-line. We also added metrical and rhyme anomalies. We hypothesized that silently reading MRRL results in building up auditive expectations that are based on a rhythmic “audible gestalt” and propose that rhythmicity is generated through subvocalization. Our results revealed that readers were sensitive to rhythmic-gestalt-anomalies but showed differential effects in poem and prose layouts. Metrical anomalies in particular resulted in robust reading disruptions across a variety of eye-movement measures in the poem layout and caused re-reading of the local context. Rhyme anomalies elicited stronger effects in prose layout and resulted in systematic re-reading of pre-rhymes. The presence or absence of rhythmic-gestalt-anomalies, as well as the layout manipulation, also affected reading in general. Effects of syllable number indicated a high degree of subvocalization. The overall pattern of results suggests that eye-movements reflect, and are closely aligned with, the rhythmic subvocalization of MRRL.

This study introduces a two-stage approach to the analysis of long MRRL stimuli and contributes to the discussion of how the processing of rhythm in music and speech may overlap.

The impact of musical expertise on anticipatory semantic processing during online speech comprehension: An electroencephalography study

Musical experience has been found to aid speech perception. This electroencephalography study further examined whether and how musical expertise affects high-level predictive semantic processing in speech comprehension. Musicians and non-musicians listened to semantically strongly/weakly constraining sentences, with each sentence being primed by a congruent/incongruent sentence-prosody. At the target nouns, a N400 reduction effect (strongly vs. weakly constraining) was observed in both groups, with the onset-latency of this effect being delayed for incongruent (vs. congruent) priming. At the transitive verbs preceding these target nouns, musicians' event-related-potential amplitude (in incongruent-priming) and beta-band oscillatory power (in congruent- and incongruent-priming) showed a semantic-constraint effect, and were correlated with the predictability of incoming nouns; non-musicians only demonstrated an event-related-potential semantic-constraint effect, which was correlated with the predictability of current verbs. These results indicate musical expertise enhances semantic prediction tendency in speech comprehension, and this effect might be not just an aftereffect of facilitated acoustic/phonological processing.

Linguistic syncopation: Meter-syntax alignment affects sentence comprehension and sensorimotor synchronization

The hierarchical organization of speech rhythm into meter putatively confers cognitive affordances for perception, memory, and motor coordination. Meter also aligns with phrasal structure in systematic ways. In this paper, we show that this alignment affects the robustness of syntactic comprehension and discuss possible underlying mechanisms. In two experiments, we manipulated meter-syntax alignment while sentences with relative clause structures were either read as text (experiment 1, n = 40) or listened to as speech (experiment 2, n = 40). In experiment 2, we also measured the stability with which participants could tap in time with the metrical accents in the sentences they were comprehending. In addition to making more mistakes, sensorimotor synchronization was disrupted when syntactic cues clashed with the metrical context. We suggest that this reflects a tight coordination of top-down linguistic knowledge with the sensorimotor system to optimize comprehension.

One Way or Another: Cortical Language Areas Flexibly Adapt Processing Strategies to Perceptual And Contextual Properties of Speech

Cortical circuits rely on the temporal regularities of speech to optimize signal parsing for sound-to-meaning mapping. Bottom-up speech analysis is accelerated by top-down predictions about upcoming words. In everyday communications, however, listeners are regularly presented with challenging input-fluctuations of speech rate or semantic content. In this study, we asked how reducing speech temporal regularity affects its processing-parsing, phonological analysis, and ability to generate context-based predictions. To ensure that spoken sentences were natural and approximated semantic constraints of spontaneous speech we built a neural network to select stimuli from large corpora. We analyzed brain activity recorded with magnetoencephalography during sentence listening using evoked responses, speech-to-brain synchronization and representational similarity analysis. For normal speech theta band (6.5-8 Hz) speech-to-brain synchronization was increased and the left fronto-temporal areas generated stronger contextual predictions. The reverse was true for temporally irregular speech-weaker theta synchronization and reduced top-down effects. Interestingly, delta-band (0.5 Hz) speech tracking was greater when contextual/semantic predictions were lower or if speech was temporally jittered. We conclude that speech temporal regularity is relevant for (theta) syllabic tracking and robust semantic predictions while the joint support of temporal and contextual predictability reduces word and phrase-level cortical tracking (delta).

Hierarchical control as a shared neurocognitive mechanism for language and music

Although comparative research has made substantial progress in clarifying the relationship between language and music as neurocognitive systems from both a theoretical and empirical perspective, there is still no consensus about which mechanisms, if any, are shared and how they bring about different neurocognitive systems. In this paper, we tackle these two questions by focusing on hierarchical control as a neurocognitive mechanism underlying syntax in language and music. We put forward the Coordinated Hierarchical Control (CHC) hypothesis: linguistic and musical syntax rely on hierarchical control, but engage this shared mechanism differently depending on the current control demand. While linguistic syntax preferably engages the abstract rule-based control circuit, musical syntax rather employs the coordination of the abstract rule-based and the more concrete motor-based control circuits. We provide evidence for our hypothesis by reviewing neuroimaging as well as neuropsychological studies on linguistic and musical syntax. The CHC hypothesis makes a set of novel testable predictions to guide future work on the relationship between language and music.

Dynamic acoustic salience evokes motor responses

Audio-motor integration is currently viewed as a predictive process in which the brain simulates upcoming sounds based on voluntary actions. This perspective does not consider how our auditory environment may trigger involuntary action in the absence of prediction. We address this issue by examining the relationship between acoustic salience and involuntary motor responses. We investigate how acoustic features in music contribute to the perception of salience, and whether those features trigger involuntary peripheral motor responses. Participants with little-to-no musical training listened to musical excerpts once while remaining still during the recording of their muscle activity with surface electromyography (sEMG), and again while they continuously rated perceived salience within the music using a slider. We show cross-correlations between 1) salience ratings and acoustic features, 2) acoustic features and spontaneous muscle activity, and 3) salience ratings and spontaneous muscle activity. Amplitude, intensity, and spectral centroid were perceived as the most salient features in music, and fluctuations in these features evoked involuntary peripheral muscle responses. Our results suggest an involuntary mechanism for audio-motor integration, which may rely on brainstem-spinal or brainstem-cerebellar-spinal pathways. Based on these results, we argue that a new framework is needed to explain the full range of human sensorimotor capabilities. This goal can be achieved by considering how predictive and reactive audio-motor integration mechanisms could operate independently or interactively to optimize human behavior.

The effect of regular rhythm on the perception of linguistic and non-linguistic auditory input

Regular distribution of auditory stimuli over time can facilitate perception and attention. However, such effects have to date only been observed in separate studies using either linguistic or non-linguistic materials. This has made it difficult to compare the effects of rhythmic regularity on attention across domains. The current study was designed to provide an explicit within-subject comparison of reaction times and accuracy in an auditory target-detection task using sequences of regularly and irregularly distributed syllables (linguistic material) and environmental sounds (non-linguistic material). We explored how reaction times and accuracy were modulated by regular and irregular rhythms in a sound- (non-linguistic) and syllable-monitoring (linguistic) task performed by native Spanish speakers (N = 25). Surprisingly, we did not observe that regular rhythm exerted a facilitatory effect on reaction times or accuracy. Further exploratory analysis showed that targets that appear later in sequences of syllables and sounds are identified more quickly. In late targets, reaction times in stimuli with a regular rhythm were lower than in stimuli with irregular rhythm for linguistic material, but not for non-linguistic material. The difference in reaction times on stimuli with regular and irregular rhythm for late targets was also larger for linguistic than for non-linguistic material. This suggests a modulatory effect of rhythm on linguistic stimuli only once the percept of temporal isochrony has been established. We suggest that temporal isochrony modulates attention to linguistic more than to non-linguistic stimuli because the human auditory system is tuned to process speech. The results, however, need to be further tested in confirmatory studies.

ERP mismatch response to phonological and temporal regularities in speech

Predictions of our sensory environment facilitate perception across domains. During speech perception, formal and temporal predictions may be made for phonotactic probability and syllable stress patterns, respectively, contributing to the efficient processing of speech input. The current experiment employed a passive EEG oddball paradigm to probe the neurophysiological processes underlying temporal and formal predictions simultaneously. The component of interest, the mismatch negativity (MMN), is considered a marker for experience-dependent change detection, where its timing and amplitude are indicative of the perceptual system’s sensitivity to presented stimuli. We hypothesized that more predictable stimuli (i.e. high phonotactic probability and first syllable stress) would facilitate change detection, indexed by shorter peak latencies or greater peak amplitudes of the MMN. This hypothesis was confirmed for phonotactic probability: high phonotactic probability deviants elicited an earlier MMN than low phonotactic probability deviants. We do not observe a significant modulation of the MMN to variations in syllable stress. Our findings confirm that speech perception is shaped by formal and temporal predictability. This paradigm may be useful to investigate the contribution of implicit processing of statistical regularities during (a)typical language development.

Shared neural resources of rhythm and syntax: An ALE meta-analysis

A growing body of evidence has highlighted behavioral connections between musical rhythm and linguistic syntax, suggesting that these abilities may be mediated by common neural resources. Here, we performed a quantitative meta-analysis of neuroimaging studies using activation likelihood estimate (ALE) to localize the shared neural structures engaged in a representative set of musical rhythm (rhythm, beat, and meter) and linguistic syntax (merge movement, and reanalysis) operations. Rhythm engaged a bilateral sensorimotor network throughout the brain consisting of the inferior frontal gyri, supplementary motor area, superior temporal gyri/temporoparietal junction, insula, intraparietal lobule, and putamen. By contrast, syntax mostly recruited the left sensorimotor network including the inferior frontal gyrus, posterior superior temporal gyrus, premotor cortex, and supplementary motor area. Intersections between rhythm and syntax maps yielded overlapping regions in the left inferior frontal gyrus, left supplementary motor area, and bilateral insula-neural substrates involved in temporal hierarchy processing and predictive coding. Together, this is the first neuroimaging meta-analysis providing detailed anatomical overlap of sensorimotor regions recruited for musical rhythm and linguistic syntax.

Rhythm in speech and animal vocalizations: a cross-species perspective

Why does human speech have rhythm? As we cannot travel back in time to witness how speech developed its rhythmic properties and why humans have the cognitive skills to process them, we rely on alternative methods to find out. One powerful tool is the comparative approach: studying the presence or absence of cognitive/behavioral traits in other species to determine which traits are shared between species and which are recent human inventions. Vocalizations of many species exhibit temporal structure, but little is known about how these rhythmic structures evolved, are perceived and produced, their biological and developmental bases, and communicative functions. We review the literature on rhythm in speech and animal vocalizations as a first step toward understanding similarities and differences across species. We extend this review to quantitative techniques that are useful for computing rhythmic structure in acoustic sequences and hence facilitate cross-species research. We report links between vocal perception and motor coordination and the differentiation of rhythm based on hierarchical temporal structure. While still far from a complete cross-species perspective of speech rhythm, our review puts some pieces of the puzzle together.

Word Recall is Affected by Surrounding Metrical Context

It has been claimed that English has a metrical structure, or rhythm, in which stressed and unstressed syllables alternate. In previous research regular, alternating patterns have been shown to facilitate online language comprehension. Expanding these findings to downstream processing would lead to the prediction that metrical regularity enhances memory. Research from the memory literature, however, indicates that regular patterns are less salient and therefore less well remembered, and also that strings of similar sounds are harder to remember. This work suggests that, like lists of words with similar sounds, lists of words with similar metrical patterns are less accurately remembered than comparable metrically irregular patterns. The present study tests these conflicting predictions by examining the effects of metrical regularity in a recall task. We find that words are better recalled when they do not match their metrical context, suggesting that a regular metrical structure may not be beneficial in all contexts.

Second Language Learners' Listener Impressions of Foreigner-Directed Speech

Background According to sociolinguistic frameworks such as Communication Accommodation Theory, English native speakers modify their speech to meet the communicative needs of non-native speakers (Beebe & Giles, 1984). However, when foreigner-directed speech is used inappropriately, it may lead to overaccommodation, which in turn can act counterproductively toward communicative goals. Purpose To date, much of the research on foreigner-directed speech toward non-native speakers has focused on its acoustic parameters, but few studies have examined how second language learners interpret it emotionally and pragmatically. Method This study asked 36 English second language learners to listen to four types of speech accommodation styles (casual, clear, infant-directed, and foreigner-directed) spoken by four different speakers. Their task was to evaluate the extent to which the speaker was easy to understand, competent, condescending, friendly, and respectful. Results Acoustic analyses of the speech stimuli showed that speakers used distinct acoustic cues for each speech accommodation style, for example, slower speech rate for foreigner-directed speech. The rating results show that second language learners of English judged casual speech as least intelligible, least competent, and least friendly compared to all other speech types. Respectfulness ratings show that participants perceived casual speech as less respectful compared to clear speech and infant-directed speech, but not foreigner-directed speech. However, no effects were found for condescension. Conclusion The results suggest second language learners in the current experiment generally perceived speech accommodation positively.

Rhythmic pattern facilitates speech production: An ERP study

Rhythm affects the speech perception of events unfolding over time. However, it is not clear to what extent the rhythm could affect the processes of sentence speech production. In this event-related potential (ERP) study, we examined whether a particular rhythmic pattern could affect the planning of speech production before articulation. We recorded electrophysiological (EEG) and behavioural (reaction time) data while participants read aloud a target speech in Chinese. Target speeches were sentences or phrases consisting four characters, with regular (e.g., the 2 + 2 pattern; numbers in the brackets represent the number of syllables) or irregular (e.g., 1 + 3) rhythmic patterns, which were preceded by congruent or incongruent musical rhythmic patterns formed by simple pure tones with different temporal intervals. Behavioural and ERP findings indicated a rhythmic priming effect in comparing congruent and incongruent conditions in the regular target speeches, but not in the irregular ones. An early component (N100) that was elicited in response to target speeches that were rhythmically mismatched to primes was linked to the detection of hierarchical linguistic units, which did not conform to expectations. A later negative component (N400) was thought to reflect the violation of expectation on rhythmic pattern in speech production. These findings suggest that rhythmic pattern constrains grammatical and prosodic encoding during speech production, and support the hypothesis that speakers form a grammatical or a prosodic abstract frame before articulation.

Do Patients With Neurogenic Speech Sound Impairments Benefit From Auditory Priming With a Regular Metrical Pattern?

Purpose Earlier investigations based on word and sentence repetition tasks had revealed that the most prevalent metrical pattern in German (the trochee)-unlike the iambic pattern-facilitates articulation in patients with apraxia of speech (AOS; e.g., Aichert, Späth, & Ziegler, 2016), confirming that segmental and prosodic aspects of speech production interact. In this study, we investigated if articulation in apraxic speakers also benefits from auditory priming by speech with a regular rhythm. Furthermore, we asked if the advantage of regular speech rhythm, if present, is confined to impairments at the motor planning stage of speech production (i.e., AOS) or if it also applies to phonological encoding impairments. Method Twelve patients with AOS, 12 aphasic patients with postlexical phonological impairment (PI), and 36 neurologically healthy speakers were examined. A sequential synchronization paradigm based on a sentence completion task was conducted in conditions where we independently varied the metrical regularity of the prime sentence (regular vs. irregular prime sentence) and the metrical regularity of the target word (trochaic vs. iambic). Results Our data confirmed the facilitating effect of regular (trochaic) word stress on speech accuracy in patients with AOS (target effect). This effect could, for the first time, also be demonstrated in individuals with PI. Moreover, the study also revealed an influence of the metrical regularity of speech input in both patient groups (prime effect). Conclusions Patients with AOS and patients with PI exploited rhythmic cues in the speech of a model speaker for the initiation and the segmental realization of words. There seems to be a robust metrical influence on speech at both the phonological and the phonetic planning stages of speech production.

Event-Related Potential Evidence of Implicit Metric Structure during Silent Reading

Under the Implicit Prosody Hypothesis, readers generate prosodic structures during silent reading that can direct their real-time interpretations of the text. In the current study, we investigated the processing of implicit meter by recording event-related potentials (ERPs) while participants read a series of 160 rhyming couplets, where the rhyme target was always a stress-alternating noun–verb homograph (e.g., permit, which is pronounced PERmit as a noun and perMIT as a verb). The target had a strong–weak or weak–strong stress pattern, which was either consistent or inconsistent with the stress expectation generated by the couplet. Inconsistent strong–weak targets elicited negativities between 80–155 ms and 325–375 ms relative to consistent strong–weak targets; inconsistent weak–strong targets elicited a positivity between 365–435 ms relative to consistent weak–strong targets. These results are largely consistent with effects of metric violations during listening, demonstrating that implicit prosodic representations are similar to explicit prosodic representations.

Cross-Modal Priming Effect of Rhythm on Visual Word Recognition and Its Relationships to Music Aptitude and Reading Achievement

Recent evidence suggests the existence of shared neural resources for rhythm processing in language and music. Such overlaps could be the basis of the facilitating effect of regular musical rhythm on spoken word processing previously reported for typical children and adults, as well as adults with Parkinson’s disease and children with developmental language disorders. The present study builds upon these previous findings by examining whether non-linguistic rhythmic priming also influences visual word processing, and the extent to which such cross-modal priming effect of rhythm is related to individual differences in musical aptitude and reading skills. An electroencephalogram (EEG) was recorded while participants listened to a rhythmic tone prime, followed by a visual target word with a stress pattern that either matched or mismatched the rhythmic structure of the auditory prime. Participants were also administered standardized assessments of musical aptitude and reading achievement. Event-related potentials (ERPs) elicited by target words with a mismatching stress pattern showed an increased fronto-central negativity. Additionally, the size of the negative effect correlated with individual differences in musical rhythm aptitude and reading comprehension skills. Results support the existence of shared neurocognitive resources for linguistic and musical rhythm processing, and have important implications for the use of rhythm-based activities for reading interventions.

What does it take to stress a word? Digital manipulation of stress markers in ataxic dysarthria

BACKGROUND

Stress production is important for effective communication, but this skill is frequently impaired in people with motor speech disorders. The literature reports successful treatment of these deficits in this population, thus highlighting the therapeutic potential of this area. However, no specific guidance is currently available to clinicians about whether any of the stress markers are more effective than others, to what degree they have to be manipulated, and whether strategies need to differ according to the underlying symptoms.

AIMS

In order to provide detailed information on how stress production problems can be addressed, the study investigated (1) the minimum amount of change in a single stress marker necessary to achieve significant improvement in stress target identification; and (2) whether stress can be signalled more effectively with a combination of stress markers.

METHODS & PROCEDURES

Data were sourced from a sentence stress task performed by 10 speakers with ataxic dysarthria and 10 healthy matched control participants. Fifteen utterances perceived as having incorrect stress patterns (no stress, all words stressed or inappropriate word stressed) were selected and digitally manipulated in a stepwise fashion based on typical speaker performance. Manipulations were performed on F0, intensity and duration, either in isolation or in combination with each other. In addition, pitch contours were modified for some utterances. A total of 50 naïve listeners scored which word they perceived as being stressed.

OUTCOMES & RESULTS

Results showed that increases in duration and intensity at levels smaller than produced by the control participants resulted in significant improvements in listener accuracy. The effectiveness of F0 increases depended on the underlying error pattern. Overall intensity showed the most stable effects. Modifications of the pitch contour also resulted in significant improvements, but not to the same degree as amplification. Integration of two or more stress markers did not result in better results than manipulation of individual stress markers, unless they were combined with pitch contour modifications.

CONCLUSIONS & IMPLICATIONS

The results highlight the potential for improvement of stress production in speakers with motor speech disorders. The fact that individual parameter manipulation is as effective as combining them will facilitate the therapeutic process considerably, as will the result that amplification at lower levels than seen in typical speakers is sufficient. The difference in results across utterance sets highlights the need to investigate the underlying error pattern in order to select the most effective compensatory strategy for clients.

The Temporal Prediction of Stress in Speech and Its Relation to Musical Beat Perception

While rhythmic expectancies are thought to be at the base of beat perception in music, the extent to which stress patterns in speech are similarly represented and predicted during on-line language comprehension is debated. The temporal prediction of stress may be advantageous to speech processing, as stress patterns aid segmentation and mark new information in utterances. However, while linguistic stress patterns may be organized into hierarchical metrical structures similarly to musical meter, they do not typically present the same degree of periodicity. We review the theoretical background for the idea that stress patterns are predicted and address the following questions: First, what is the evidence that listeners can predict the temporal location of stress based on preceding rhythm? If they can, is it thanks to neural entrainment mechanisms similar to those utilized for musical beat perception? And lastly, what linguistic factors other than rhythm may account for the prediction of stress in natural speech? We conclude that while expectancies based on the periodic presentation of stresses are at play in some of the current literature, other processes are likely to affect the prediction of stress in more naturalistic, less isochronous speech. Specifically, aspects of prosody other than amplitude changes (e.g., intonation) as well as lexical, syntactic and information structural constraints on the realization of stress may all contribute to the probabilistic expectation of stress in speech.

Effects of metric hierarchy and rhyme predictability on word duration in The Cat in the Hat

Word durations convey many types of linguistic information, including intrinsic lexical features like length and frequency and contextual features like syntactic and semantic structure. The current study was designed to investigate whether hierarchical metric structure and rhyme predictability account for durational variation over and above other features in productions of a rhyming, metrically-regular children's book: The Cat in the Hat (Dr. Seuss, 1957). One-syllable word durations and inter-onset intervals were modeled as functions of segment number, lexical frequency, word class, syntactic structure, repetition, and font emphasis. Consistent with prior work, factors predicting longer word durations and inter-onset intervals included more phonemes, lower frequency, first mention, alignment with a syntactic boundary, and capitalization. A model parameter corresponding to metric grid height improved model fit of word durations and inter-onset intervals. Specifically, speakers realized five levels of metric hierarchy with inter-onset intervals such that interval duration increased linearly with increased height in the metric hierarchy. Conversely, speakers realized only three levels of metric hierarchy with word duration, demonstrating that they shortened the highly predictable rhyme resolutions. These results further understanding of the factors that affect spoken word duration, and demonstrate the myriad cues that children receive about linguistic structure from nursery rhymes.

Rhythmic facilitation of sensory processing: A critical review

Here we review the role of brain oscillations in sensory processing. We examine the idea that neural entrainment of intrinsic oscillations underlies the processing of rhythmic stimuli in the context of simple isochronous rhythms as well as in music and speech. This has been a topic of growing interest over recent years; however, many issues remain highly controversial: how do fluctuations of intrinsic neural oscillations-both spontaneous and entrained to external stimuli-affect perception, and does this occur automatically or can it be actively controlled by top-down factors? Some of the controversy in the literature stems from confounding use of terminology. Moreover, it is not straightforward how theories and findings regarding isochronous rhythms generalize to more complex, naturalistic stimuli, such as speech and music. Here we aim to clarify terminology, and distinguish between different phenomena that are often lumped together as reflecting "neural entrainment" but may actually vary in their mechanistic underpinnings. Furthermore, we discuss specific caveats and confounds related to making inferences about oscillatory mechanisms from human electrophysiological data.

Sentence-Level Effects of Literary Genre: Behavioral and Electrophysiological Evidence

The current study used event-related brain potentials (ERPs) and behavioral measures to examine effects of genre awareness on sentence processing and evaluation. We hypothesized that genre awareness modulates effects of genre-typical manipulations. We manipulated instructions between participants, either specifying a genre (poetry) or not (neutral). Sentences contained genre-typical variations of semantic congruency (congruent/incongruent) and morpho-phonological features (archaic/contemporary inflections). Offline ratings of meaningfulness (n = 64/group) showed higher average ratings for semantically incongruent sentences in the poetry vs. neutral condition. ERPs during sentence reading (n = 24/group; RSVP presentation at a fixed per-constituent rate; probe task) showed a left-lateralized N400-like effect for contemporary vs. archaic inflections. Semantic congruency elicited a bilateral posterior N400 effect for incongruent vs. congruent continuations followed by a centro-parietal positivity (P600). While N400 amplitudes were insensitive to the genre, the latency of the P600 was delayed by the poetry instruction. From these results, we conclude that during real-time sentence comprehension, readers are sensitive to subtle morphological manipulations and the implicit prosodic differences that accompany them. By contrast, genre awareness affects later stages of comprehension.

The Role of Slow Speech Amplitude Envelope for Speech Processing and Reading Development

This study examined the putative link between the entrainment to the slow rhythmic structure of speech, speech intelligibility and reading by means of a behavioral paradigm. Two groups of 20 children (Grades 2 and 5) were asked to recall a pseudoword embedded in sentences presented either in quiet or noisy listening conditions. Half of the sentences were primed with their syllabic and prosodic amplitude envelope to determine whether a boost in auditory entrainment to these speech features enhanced pseudoword intelligibility. Priming improved pseudoword recall performance only for the older children both in a quiet and a noisy listening environment, and such benefit from the prime correlated with reading skills and pseudoword recall. Our results support the role of syllabic and prosodic tracking of speech in reading development.

Musical training modulates the early but not the late stage of rhythmic syntactic processing

Syntactic processing is essential for musical understanding. Although the processing of harmonic syntax has been well studied, very little is known about the neural mechanisms underlying rhythmic syntactic processing. The present study investigated the neural processing of rhythmic syntax and whether and to what extent long-term musical training impacts such processing. Fourteen musicians and 14 nonmusicians listened to syntactic-regular or syntactic-irregular rhythmic sequences and judged the completeness of these sequences. Nonmusicians, as well as musicians, showed a P600 effect to syntactic-irregular endings, indicating that musical exposure and perceptual learning of music are sufficient to enable nonmusicians to process rhythmic syntax at the late stage. However, musicians, but not nonmusicians, also exhibited an early right anterior negativity (ERAN) response to syntactic-irregular endings, which suggests that musical training only modulates the early but not the late stage of rhythmic syntactic processing. These findings revealed for the first time the neural mechanisms underlying the processing of rhythmic syntax in music, which has important implications for theories of hierarchically organized music cognition and comparative studies of syntactic processing in music and language.

Brain-to-brain entrainment: EEG interbrain synchronization while speaking and listening

Electroencephalographic hyperscanning was used to investigate interbrain synchronization patterns in dyads of participants interacting through speech. Results show that brain oscillations are synchronized between listener and speaker during oral narratives. This interpersonal synchronization is mediated in part by a lower-level sensory mechanism of speech-to-brain synchronization, but also by the interactive process that takes place in the situation per se. These results demonstrate the existence of brain-to-brain entrainment which is not merely an epiphenomenon of auditory processing, during listening to one speaker. The study highlights the validity of the two-person neuroscience framework for understanding induced brain activity, and suggests that verbal information exchange cannot be fully understood by examining the listener’s or speaker’s brain activity in isolation.

Tuning Neural Phase Entrainment to Speech

Musical rhythm positively impacts on subsequent speech processing. However, the neural mechanisms underlying this phenomenon are so far unclear. We investigated whether carryover effects from a preceding musical cue to a speech stimulus result from a continuation of neural phase entrainment to periodicities that are present in both music and speech. Participants listened and memorized French metrical sentences that contained (quasi-)periodic recurrences of accents and syllables. Speech stimuli were preceded by a rhythmically regular or irregular musical cue. Our results show that the presence of a regular cue modulates neural response as estimated by EEG power spectral density, intertrial coherence, and source analyses at critical frequencies during speech processing compared with the irregular condition. Importantly, intertrial coherences for regular cues were indicative of the participants' success in memorizing the subsequent speech stimuli. These findings underscore the highly adaptive nature of neural phase entrainment across fundamentally different auditory stimuli. They also support current models of neural phase entrainment as a tool of predictive timing and attentional selection across cognitive domains.

Aesthetic appreciation of poetry correlates with ease of processing in event-related potentials

Rhetorical theory suggests that rhythmic and metrical features of language substantially contribute to persuading, moving, and pleasing an audience. A potential explanation of these effects is offered by "cognitive fluency theory," which stipulates that recurring patterns (e.g., meter) enhance perceptual fluency and can lead to greater aesthetic appreciation. In this article, we explore these two assertions by investigating the effects of meter and rhyme in the reception of poetry by means of event-related brain potentials (ERPs). Participants listened to four versions of lyrical stanzas that varied in terms of meter and rhyme, and rated the stanzas for rhythmicity and aesthetic liking. The behavioral and ERP results were in accord with enhanced liking and rhythmicity ratings for metered and rhyming stanzas. The metered and rhyming stanzas elicited smaller N400/P600 ERP responses than their nonmetered, nonrhyming, or nonmetered and nonrhyming counterparts. In addition, the N400 and P600 effects for the lyrical stanzas correlated with aesthetic liking effects (metered-nonmetered), implying that modulation of the N400 and P600 has a direct bearing on the aesthetic appreciation of lyrical stanzas. We suggest that these effects are indicative of perceptual-fluency-enhanced aesthetic liking, as postulated by cognitive fluency theory.

Processing Metrical Information in Silent Reading: An ERP Study

Listeners are sensitive to the metric structure of words, i.e., an alternating pattern of stressed and unstressed syllables, in auditory speech processing: Event-related potentials recorded as participants listen to a sequence of words with a consistent metrical pattern, e.g., a series of trochaic words, suggest that participants register words metrically incongruent with the preceding sequence. Here we examine whether the processing of individual words in silent reading is similarly impacted by rhythmic properties of the surrounding context. We recorded participants’ EEG as they read lists of either three trochaic or iambic disyllabic words followed by a target word that was either congruent or incongruent with the preceding metric pattern. Event-Related Potentials (ERPs) to targets were modulated by an interaction between metrical structure (iambic vs. trochaic) and congruence: for iambs, more positive ERPs were observed in the incongruent than congruent condition 250–400 ms and 400–600 ms post-stimulus, whereas no reliable impact of congruence was found for trochees. We suggest that when iambs are in an incongruent context, i.e., preceded by trochees, the context contains the metrical structure that is more typical in participants’ native language which facilitates processing relative to when they are presented in a congruent context, containing the less typical, i.e., iambic, metrical structure. The results provide evidence that comprehenders are sensitive to the prosodic properties of the context even in silent reading, such that this sensitivity impacts lexico-semantic processing of individual words.

Speech rhythm alterations in Spanish-speaking individuals with Alzheimer's disease

Rhythm is the speech property related to the temporal organization of sounds. Considerable evidence is now available for suggesting that dementia of Alzheimer's type is associated with impairments in speech rhythm. The aim of this study is to assess the use of an automatic computerized system for measuring speech rhythm characteristics in an oral reading task performed by 45 patients with Alzheimer's disease (AD) compared with those same characteristics among 82 healthy older adults without a diagnosis of dementia, and matched by age, sex and cultural background. Ranges of rhythmic-metric and clinical measurements were applied. The results show rhythmic differences between the groups, with higher variability of syllabic intervals in AD patients. Signal processing algorithms applied to oral reading recordings prove to be capable of differentiating between AD patients and older adults without dementia with an accuracy of 87% (specificity 81.7%, sensitivity 82.2%), based on the standard deviation of the duration of syllabic intervals. Experimental results show that the syllabic variability measurements extracted from the speech signal can be used to distinguish between older adults without a diagnosis of dementia and those with AD, and may be useful as a tool for the objective study and quantification of speech deficits in AD.

The strong, the weak, and the first: The impact of phonological stress on processing of orthographic errors in silent reading

In auditory speech processing, phonological stress functions as an attention holding cue, which facilitates detection of mispronunciations and phonetic deviants in strong syllables as compared to weak ones. Whereas silent reading involves activation of phonological information including word stress, it is not clear whether it has any functional relevance for visual language processing. We investigated whether phonological stress impacts orthographic processing such as detection of misspellings in silent reading. In an ERP experiment, participants silently read intact and misspelled German words. We manipulated the strength of the misspelled syllable (strong vs. weak) as well as its position (word-initial vs. word-middle). No effect of stress was observed for misspellings occurring in a word-initial position suggesting that misspellings in word-initial position disrupt visual word processing regardless of the phonological strength of the first syllable. In contrast, phonological strength modulated the ERPs when misspellings occurred in the middle of the word: misspellings embedded in strong syllables enhanced the P600 and the N400-like component compared to misspellings in weak syllables. In this case, i.e., when misspellings occur in the middle of a letter string, lexical access may be hindered more when errors occur in strong syllables, as reflected in the enhanced N400 in strong compared to weak syllables. This in turn may facilitate active reanalysis as mirrored in the increased P600 in the strong condition. The findings are discussed in the context of the relatively late activation of phonological form in visual word recognition and its interaction with other perceptual visual information. Overall, the results demonstrate the functional significance of phonological stress in visual word processing.

Speech rhythm sensitivity and musical aptitude: ERPs and individual differences

This study investigated the electrophysiological markers of rhythmic expectancy during speech perception. In addition, given the large literature showing overlaps between cognitive and neural resources recruited for language and music, we considered a relation between musical aptitude and individual differences in speech rhythm sensitivity. Twenty adults were administered a standardized assessment of musical aptitude, and EEG was recorded as participants listened to sequences of four bisyllabic words for which the stress pattern of the final word either matched or mismatched the stress pattern of the preceding words. Words with unexpected stress patterns elicited an increased fronto-central mid-latency negativity. In addition, rhythm aptitude significantly correlated with the size of the negative effect elicited by unexpected iambic words, the least common type of stress pattern in English. The present results suggest shared neurocognitive resources for speech rhythm and musical rhythm.

Entraining with another person's speech rhythm: Evidence from healthy speakers and individuals with Parkinson's disease

This study examines entrainment of speech timing and rhythm with a model speaker in healthy persons and individuals with Parkinson's. We asked whether participants coordinate their speech initiation and rhythm with the model speaker, and whether the regularity of metrical structure of sentences influences this behaviour. Ten native German speakers with hypokinetic dysarthria following Parkinson's and 10 healthy controls heard a sentence ('prime') and subsequently read aloud another sentence ('target'). Speech material comprised 32 metrically regular and irregular sentences, respectively. Turn-taking delays and alignment of speech rhythm were measured using speech wave analyses. Results showed that healthy participants initiated speech more closely in rhythm with the model speaker than patients. Metrically regular prime sentences induced anticipatory responses relative to metrically irregular primes. Entrainment of speech rhythm was greater in metrically regular targets, especially in individuals with Parkinson's. We conclude that individuals with Parkinson's may exploit metrically regular cues in speech.

Word Detection in Sung and Spoken Sentences in Children With Typical Language Development or With Specific Language Impairment

Background: Previous studies have reported that children score better in language tasks using sung rather than spoken stimuli. We examined word detection ease in sung and spoken sentences that were equated for phoneme duration and pitch variations in children aged 7 to 12 years with typical language development (TLD) as well as in children with specific language impairment (SLI ), and hypothesized that the facilitation effect would vary with language abilities. Method: In Experiment 1, 69 children with TLD (7–10 years old) detected words in sentences that were spoken, sung on pitches extracted from speech, and sung on original scores. In Experiment 2, we added a natural speech rate condition and tested 68 children with TLD (7–12 years old). In Experiment 3, 16 children with SLI and 16 age-matched children with TLD were tested in all four conditions. Results: In both TLD groups, older children scored better than the younger ones. The matched TLD group scored higher than the SLI group who scored at the level of the younger children with TLD . None of the experiments showed a facilitation effect of sung over spoken stimuli. Conclusions: Word detection abilities improved with age in both TLD and SLI groups. Our findings are compatible with the hypothesis of delayed language abilities in children with SLI , and are discussed in light of the role of durational prosodic cues in words detection.

Processing Rhythmic Pattern during Chinese Sentence Reading: An Eye Movement Study

Prosodic constraints play a fundamental role during both spoken sentence comprehension and silent reading. In Chinese, the rhythmic pattern of the verb-object (V-O) combination has been found to rapidly affect the semantic access/integration process during sentence reading (Luo and Zhou, 2010). Rhythmic pattern refers to the combination of words with different syllabic lengths, with certain combinations disallowed (e.g., [2 + 1]; numbers standing for the number of syllables of the verb and the noun respectively) and certain combinations preferred (e.g., [1 + 1] or [2 + 2]). This constraint extends to the situation in which the combination is used to modify other words. A V-O phrase could modify a noun by simply preceding it, forming a V-O-N compound; when the verb is disyllabic, however, the word order has to be O-V-N and the object is preferred to be disyllabic. In this study, we investigated how the reader processes the rhythmic pattern and word order information by recording the reader's eye-movements. We created four types of sentences by crossing rhythmic pattern and word order in compounding. The compound, embedding a disyllabic verb, could be in the correct O-V-N or the incorrect V-O-N order; the object could be disyllabic or monosyllabic. We found that the reader spent more time and made more regressions on and after the compounds when either type of anomaly was detected during the first pass reading. However, during re-reading (after all the words in the sentence have been viewed), less regressive eye movements were found for the anomalous rhythmic pattern, relative to the correct pattern; moreover, only the abnormal rhythmic pattern, not the violated word order, influenced the regressive eye movements. These results suggest that while the processing of rhythmic pattern and word order information occurs rapidly during the initial reading of the sentence, the process of recovering from the rhythmic pattern anomaly may ease the reanalysis processing at the later stage of sentence integration. Thus, rhythmic pattern in Chinese can dynamically affect both local phrase analysis and global sentence integration during silent reading.

Attentional entrainment and perceived event duration

This study considered the contribution of dynamic attending theory (DAT) and attentional entrainment to systematic distortions in perceived event duration. Three experiments were conducted using an auditory oddball paradigm, in which listeners judged the duration of a deviant (oddball) stimulus embedded within a series of identical (standard) stimuli. To test for a role of attentional entrainment in perceived oddball duration, oddballs were presented at either temporally expected (on time) or unexpectedly early or late time points relative to extrapolation of the context rhythm. Consistent with involvement of attentional entrainment in perceived duration, duration judgements about the oddball were least distorted when the oddball occurred on time with respect to the entrained rhythm, whereas durations of early and late oddballs were perceived to be shorter and longer, respectively. This pattern of results was independent of the absolute time interval preceding the oddball. Moreover, as expected, an irregularly timed sequence context weakened observed differences between oddballs with on-time and late onsets. Combined with other recent work on the role of temporal preparation in duration distortions, the present findings allot at least a portion of the oddball effect to increased attention to events that are more expected, rather than on their unexpected nature per se.

The role of rhythm in perceiving speech in noise: a comparison of percussionists, vocalists and non-musicians

The natural rhythms of speech help a listener follow what is being said, especially in noisy conditions. There is increasing evidence for links between rhythm abilities and language skills; however, the role of rhythm-related expertise in perceiving speech in noise is unknown. The present study assesses musical competence (rhythmic and melodic discrimination), speech-in-noise perception and auditory working memory in young adult percussionists, vocalists and non-musicians. Outcomes reveal that better ability to discriminate rhythms is associated with better sentence-in-noise (but not words-in-noise) perception across all participants. These outcomes suggest that sensitivity to rhythm helps a listener understand unfolding speech patterns in degraded listening conditions, and that observations of a "musician advantage" for speech-in-noise perception may be mediated in part by superior rhythm skills.

Do metrical incongruities disrupt semantic processing in modern Chinese? An event-related potential study

The present study examined the relationship between prosody and semantic processing in the written form of modern Chinese by analysing behavioural data and event-related potential data. By manipulating the number of noun syllables in verb-objection, we compare the dynamic neural mechanisms of the structure bisyllabic verb (V2)+monosyllabic noun (N1) (i.e. V2+N1) with V2+N1 (N2, bisyllabic noun). In Chinese, the rhythmic pattern V2+N1 is considered to be a metrical incongruity, whereas V2+N2 is considered to be a metrical congruity. For example, the verb yunshu (to transport) can be followed by liangshi (cereals). However, if yunshu is followed by liang (cereals), yunshu liang is usually considered to be metrically incongruous. This paper shows that (i) V2+N1 elicited more negative amplitudes than V2+N2 in the 90-170 ms and 450-500 ms windows, which indicates that metrical incongruities affect semantic processing in Chinese, and (ii) the acceptance rate for V2+N1 is significantly lower than that of V2+N2, which implies that metrical incongruities disrupt semantic processing in modern Chinese. These results are in agreement with previous studies. This is the first study to find that metrical incongruities disrupt semantic processing in Chinese. This study provides convergent evidence that metrical congruities facilitate semantic processing, whereas metrical incongruities disrupt semantic processing. Video abstract available (Supplemental digital content 1, http://links.lww.com/WNR/A340).

How information structure influences the processing of rhythmic irregularities: ERP evidence from German phrases

This study explores the influence of focus and givenness on the cognitive processing of rhythmic irregularities occurring in natural speech. Previous ERP studies showed that even subtle rhythmic deviations are detected by the brain if attention is directed towards the rhythmic structure. By using question-answer pairs, it was investigated whether subtle rhythmic irregularities in form of stress clashes (two adjacent stressed syllables) and stress lapses (two adjacent unstressed syllables) are still perceived when presented in post-focus position in an answer sentence and attention is directed away from them, towards the meaning of the element in narrow focus position by the preceding wh-question. Moreover, by visually presenting the lexical-semantic input of the deviating structure in the question, the influence of rhythmical and lexical properties in these two forms of rhythmic deviations are disentangled. While words in the present stress clash condition do not deviate from lexical stress, stress lapses contain deviations from metrical and lexical stress. The data reveal an early negativity effect for stress clashes but not for stress lapses, supporting the assumption that they are processed differently. The absence of a negative component for stress lapses indicates that the metrical deviation alone is not salient enough to be registered in non-focus position. Moreover, the lack of a late positive component suggests that subtle rhythmic deviations are less perceivable and hence more acceptable when presented in non-focus position. Thus, these results show that attentional shift induced by information structure influences the degree of the processing of rhythm.

Rhetorical features facilitate prosodic processing while handicapping ease of semantic comprehension

Studies on rhetorical features of language have reported both enhancing and adverse effects on ease of processing. We hypothesized that two explanations may account for these inconclusive findings. First, the respective gains and losses in ease of processing may apply to different dimensions of language processing (specifically, prosodic and semantic processing) and different types of fluency (perceptual vs. conceptual) and may well allow for an integration into a more comprehensive framework. Second, the effects of rhetorical features may be sensitive to interactions with other rhetorical features; employing a feature separately or in combination with others may then predict starkly different effects. We designed a series of experiments in which we expected the same rhetorical features of the very same sentences to exert adverse effects on semantic (conceptual) fluency and enhancing effects on prosodic (perceptual) fluency. We focused on proverbs that each employ three rhetorical features: rhyme, meter, and brevitas (i.e., artful shortness). The presence of these target features decreased ease of conceptual fluency (semantic comprehension) while enhancing perceptual fluency as reflected in beauty and succinctness ratings that were mainly driven by prosodic features. The rhetorical features also predicted choices for persuasive purposes, yet only for the sentence versions featuring all three rhetorical features; the presence of only one or two rhetorical features had an adverse effect on the choices made. We suggest that the facilitating effects of a combination of rhyme, meter, and rhetorical brevitas on perceptual (prosodic) fluency overcompensated for their adverse effects on conceptual (semantic) fluency, thus resulting in a total net gain both in processing ease and in choices for persuasive purposes.