Perceptual formant discrimination during speech movement planning.

Evoked potential studies have shown that speech planning modulates auditory cortical responses. The phenomenon's functional relevance is unknown. We tested whether, during this time window of cortical auditory modulation, there is an effect on speakers' perceptual sensitivity for vowel formant discrimination. Participants made same/different judgments for pairs of stimuli consisting of a pre-recorded, self-produced vowel and a formant-shifted version of the same production. Stimuli were presented prior to a "go" signal for speaking, prior to passive listening, and during silent reading. The formant discrimination stimulus /uh/ was tested with a congruent productions list (words with /uh/) and an incongruent productions list (words without /uh/). Logistic curves were fitted to participants' responses, and the just-noticeable difference (JND) served as a measure of discrimination sensitivity. We found a statistically significant effect of condition (worst discrimination before speaking) without congruency effect. Post-hoc pairwise comparisons revealed that JND was significantly greater before speaking than during silent reading. Thus, formant discrimination sensitivity was reduced during speech planning regardless of the congruence between discrimination stimulus and predicted acoustic consequences of the planned speech movements. This finding may inform ongoing efforts to determine the functional relevance of the previously reported modulation of auditory processing during speech planning.

Evidence of validity and reliability of the Compressed Speech Test with Figures. / Evidências de validade e fidedignidade do Teste de Fala Comprimida com Figuras.

PURPOSE: To seek evidence of validity and reliability for the Compressed Speech Test with Figures. METHODS: The study was subdivided into three stages: construct validation, criteria and reliability. All participants were aged between 6:00 and 8:11. For the construct, Compressed Speech with Figures and the gold standard Adapted Compressed Speech test were applied to children with typical phonological development. For criterion analysis, Compressed Speech with Figures was applied in two groups, with typical (G1) and atypical (G2) phonological development. Finally, the application protocols underwent analysis by two Speech Therapists, with experience in the area of Central Auditory Processing, seeking to obtain an inter-evaluator reliability analysis. RESULTS: The correlation test indicated an almost perfect construct (correlation 0.843 for the right ear and 0.823 for the left ear). In the criterion analysis, it was noticed that both groups presented satisfactory results (G1 = 99.6 to 100%; G2 = 96 to 96.5%). The reliability analysis demonstrated that the protocol is easy to analyze, as both professionals presented unanimous responses. CONCLUSION: It was possible to obtain evidence of validity and reliability for the Compressed Speech with Figures instrument. The construct analysis showed that the instrument measures the same variable as the gold standard test, with an almost perfect correlation. In the criterion analysis, both groups presented similar performance, demonstrating that the instrument does not seem to differentiate populations with and without mild phonological disorder. The inter-evaluator reliability analysis demonstrated that the protocol is easy to analyze and score.

OBJETIVO: Buscar evidências de validade e fidedignidade para o Teste de Fala Comprimida com Figuras. MÉTODO: O estudo foi subdividido em três etapas: validação de construto, critério e fidedignidade. Todos os participantes tinham idade entre 6:00 e 8:11. Para o construto, aplicou-se o Fala Comprimida com Figuras e o teste padrão ouro Fala Comprimida Adaptado em crianças com desenvolvimento fonológico típico. Para análise de critério, aplicou-se o Fala Comprimida com Figuras em dois grupos, com desenvolvimento fonológico típico (G1) e atípico (G2). Por fim, os protocolos de aplicação passaram pela análise de duas Fonoaudiólogas, com experiência na área do Processamento Auditivo Central, buscando obter uma análise de fidedignidade interavaliadores. RESULTADOS: O teste de correlação indicou um construto quase perfeito (Rho=0,843 para orelha direita e Rho=0,823 para orelha esquerda). Na análise de critério, percebeu-se que ambos os grupos apresentaram resultados satisfatórios (G1 = 99,6 a 100%; G2 = 96 a 96,5%). Já a análise de fidedignidade demonstrou que o protocolo é de fácil análise, pois ambos os profissionais apresentaram respostas unânimes. CONCLUSÃO: Foi possível obter evidências de validade e fidedignidade para o instrumento de Fala Comprimida com Figuras. A análise de construto evidenciou que o instrumento mede a mesma variável que o teste padrão outro, com correlação quase perfeita. Na análise de critério, ambos os grupos apresentaram desempenho semelhante, demonstrando que o instrumento não parece diferenciar populações com e sem transtorno fonológico leve. A análise de fidedignidade interavaliador demonstrou que o protocolo é de fácil análise e pontuação.

Voice Synthesis Improvement by Machine Learning of Natural Prosody.

Since the advent of modern computing, researchers have striven to make the human-computer interface (HCI) as seamless as possible. Progress has been made on various fronts, e.g., the desktop metaphor (interface design) and natural language processing (input). One area receiving attention recently is voice activation and its corollary, computer-generated speech. Despite decades of research and development, most computer-generated voices remain easily identifiable as non-human. Prosody in speech has two primary components-intonation and rhythm-both often lacking in computer-generated voices. This research aims to enhance computer-generated text-to-speech algorithms by incorporating melodic and prosodic elements of human speech. This study explores a novel approach to add prosody by using machine learning, specifically an LSTM neural network, to add paralinguistic elements to a recorded or generated voice. The aim is to increase the realism of computer-generated text-to-speech algorithms, to enhance electronic reading applications, and improved artificial voices for those in need of artificial assistance to speak. A computer that is able to also convey meaning with a spoken audible announcement will also improve human-to-computer interactions. Applications for the use of such an algorithm may include improving high-definition audio codecs for telephony, renewing old recordings, and lowering barriers to the utilization of computing. This research deployed a prototype modular platform for digital speech improvement by analyzing and generalizing algorithms into a modular system through laboratory experiments to optimize combinations and performance in edge cases. The results were encouraging, with the LSTM-based encoder able to produce realistic speech. Further work will involve optimizing the algorithm and comparing its performance against other approaches.

Perceiving and misperceiving speech: lexical and sublexical processing in the superior temporal lobes.

Listeners can use prior knowledge to predict the content of noisy speech signals, enhancing perception. However, this process can also elicit misperceptions. For the first time, we employed a prime-probe paradigm and transcranial magnetic stimulation to investigate causal roles for the left and right posterior superior temporal gyri (pSTG) in the perception and misperception of degraded speech. Listeners were presented with spectrotemporally degraded probe sentences preceded by a clear prime. To produce misperceptions, we created partially mismatched pseudo-sentence probes via homophonic nonword transformations (e.g. The little girl was excited to lose her first tooth-Tha fittle girmn wam expited du roos har derst cooth). Compared to a control site (vertex), inhibitory stimulation of the left pSTG selectively disrupted priming of real but not pseudo-sentences. Conversely, inhibitory stimulation of the right pSTG enhanced priming of misperceptions with pseudo-sentences, but did not influence perception of real sentences. These results indicate qualitatively different causal roles for the left and right pSTG in perceiving degraded speech, supporting bilateral models that propose engagement of the right pSTG in sublexical processing.

Perceptual uncertainty explains activation differences between audiovisual congruent speech and McGurk stimuli.

Face-to-face communication relies on the integration of acoustic speech signals with the corresponding facial articulations. In the McGurk illusion, an auditory /ba/ phoneme presented simultaneously with a facial articulation of a /ga/ (i.e., viseme), is typically fused into an illusory 'da' percept. Despite its widespread use as an index of audiovisual speech integration, critics argue that it arises from perceptual processes that differ categorically from natural speech recognition. Conversely, Bayesian theoretical frameworks suggest that both the illusory McGurk and the veridical audiovisual congruent speech percepts result from probabilistic inference based on noisy sensory signals. According to these models, the inter-sensory conflict in McGurk stimuli may only increase observers' perceptual uncertainty. This functional magnetic resonance imaging (fMRI) study presented participants (20 male and 24 female) with audiovisual congruent, McGurk (i.e., auditory /ba/ + visual /ga/), and incongruent (i.e., auditory /ga/ + visual /ba/) stimuli along with their unisensory counterparts in a syllable categorization task. Behaviorally, observers' response entropy was greater for McGurk compared to congruent audiovisual stimuli. At the neural level, McGurk stimuli increased activations in a widespread neural system, extending from the inferior frontal sulci (IFS) to the pre-supplementary motor area (pre-SMA) and insulae, typically involved in cognitive control processes. Crucially, in line with Bayesian theories these activation increases were fully accounted for by observers' perceptual uncertainty as measured by their response entropy. Our findings suggest that McGurk and congruent speech processing rely on shared neural mechanisms, thereby supporting the McGurk illusion as a valid measure of natural audiovisual speech perception.

Speech-induced suppression during natural dialogues.

When engaged in a conversation, one receives auditory information from the other's speech but also from their own speech. However, this information is processed differently by an effect called Speech-Induced Suppression. Here, we studied brain representation of acoustic properties of speech in natural unscripted dialogues, using electroencephalography (EEG) and high-quality speech recordings from both participants. Using encoding techniques, we were able to reproduce a broad range of previous findings on listening to another's speech, and achieving even better performances when predicting EEG signal in this complex scenario. Furthermore, we found no response when listening to oneself, using different acoustic features (spectrogram, envelope, etc.) and frequency bands, evidencing a strong effect of SIS. The present work shows that this mechanism is present, and even stronger, during natural dialogues. Moreover, the methodology presented here opens the possibility of a deeper understanding of the related mechanisms in a wider range of contexts.

Digital Avatars and Personalized Voices-How AI Is Helping to Restore Speech to Patients.

In this Medical News article, Edward Chang, MD, chair of the department of neurological surgery at the University of California, San Francisco Weill Institute for Neurosciences joins JAMA Editor in Chief Kirsten Bibbins-Domingo, PhD, MD, MAS, to discuss the potential for AI to revolutionize communication for those unable to speak due to aphasia.

[Early indicators of childhood apraxia of speech in late talkers: general guidelines to intervention]. / Indicadores tempranos de dispraxia verbal en el inicio tardío: orientaciones para la intervención Inmaculada.

INTRODUCTION: The population of children with slow emergence of language development varies widely, both in their initial profile and in their response to intervention. In this sense, there is a group of late talkers who continue to show persistent language difficulties, in some cases exhibiting signs compatible with verbal dyspraxia. METHOD: In this paper we present the different response to intervention of two profiles of late talkers. Specifically, the Target Word© program (Hanen Centre) was implemented, which is addressed to latetalking children and their families. It combines the technique of focused stimulation with guidance to parents on strategies that stimulate global language development. RESULTS: Much of the symptomatology shown in one case of poor progress coincides with retrospective descriptions of children subsequently diagnosed with dyspraxia and can be considered early indicators of the disorder: unintelligibility, reduced consonant inventory or difficulties in word repetition. DISCUSSION: The different response to intervention contributes to diagnostic decision making and the early implementation of specific strategies directed to improve speech learning skills by incorporating motor learning principles. The few studies of intervention in suspected verbal dyspraxia in early childhood offer promising results on a variety of speech assessment indicators, and provide practitioners with valuable information with which to support the intervention in this population.

Introducción: La población de niños que comienzan con lentitud el desarrollo del lenguaje varía ampliamente, tanto en su perfil inicial como en la respuesta a la intervención. En este sentido, existe un grupo de niños, denominados hablantes tardíos, que continúan mostrando dificultades persistentes en el lenguaje. Algunos de estos niños muestran signos compatibles con la dispraxia verbal, y que se ponen de manifiesto a lo largo de la intervención. Método: En este trabajo presentamos la diferente respuesta a la intervención de dos perfiles de hablante tardío. Concretamente, se aplicó el programa Target Word©, del centro Hanen, que conjuga la técnica de la estimulación focalizada con la orientación a padres sobre estrategias que promueven el desarrollo del lenguaje. Resultados: Gran parte de la sintomatología mostrada en uno de los dos casos, que experimentó un progreso pobre, coincide con las descripciones retrospectivas de niños posteriormente diagnosticados con dispraxia y pueden considerarse indicadores tempranos del trastorno: ininteligibilidad, inventario consonántico reducido o dificultades en la repetición de palabras. Discusión: La diferente respuesta a la intervención contribuye a la toma de decisiones diagnósticas y a la aplicación temprana de estrategias específicas para la mejora de las habilidades de aprendizaje del habla mediante la incorporación de los principios del aprendizaje motor. Los escasos estudios de intervención en casos de sospecha de dispraxia verbal en la infancia temprana ofrecen resultados prometedores en diversos indicadores de evaluación del habla, y proporcionan a los profesionales una información valiosa en la que fundamentar la intervención en esta población.

Atypical beta-band effects in children with dyslexia in response to rhythmic audio-visual speech.

OBJECTIVE: Previous studies have reported atypical delta phase in children with dyslexia, and that delta phase modulates the amplitude of the beta-band response via delta-beta phase-amplitude coupling (PAC). Accordingly, the atypical delta-band effects in children with dyslexia may imply related atypical beta-band effects, particularly regarding delta-beta PAC. Our primary objective was to explore beta-band oscillations in children with and without dyslexia, to explore potentially atypical effects in the beta band in dyslexic children. METHODS: We collected EEG data during a rhythmic speech paradigm from 51 children (21 control; 30 dyslexia). We then assessed beta-band phase entrainment, beta-band angular velocity, beta-band power responses and delta-beta PAC. RESULTS: We found significant beta-band phase entrainment for control children but not for dyslexic children. Furthermore, children with dyslexia exhibited significantly faster beta-band angular velocity and significantly greater beta-band power. Delta-beta PAC was comparable in both groups. CONCLUSION: Atypical beta-band effects were observed in children with dyslexia. However, delta-beta PAC was comparable in both dyslexic and control children. SIGNIFICANCE: These findings offer further insights into the neurophysiological basis of atypical rhythmic speech processing by children with dyslexia, suggesting the involvement of a wide range of frequency bands.

Research in methodologies for modelling the oral cavity.

The paper aims to explore the current state of understanding surrounding in silico oral modelling. This involves exploring methodologies, technologies and approaches pertaining to the modelling of the whole oral cavity; both internally and externally visible structures that may be relevant or appropriate to oral actions. Such a model could be referred to as a 'complete model' which includes consideration of a full set of facial features (i.e. not only mouth) as well as synergistic stimuli such as audio and facial thermal data. 3D modelling technologies capable of accurately and efficiently capturing a complete representation of the mouth for an individual have broad applications in the study of oral actions, due to their cost-effectiveness and time efficiency. This review delves into the field of clinical phonetics to classify oral actions pertaining to both speech and non-speech movements, identifying how the various vocal organs play a role in the articulatory and masticatory process. Vitaly, it provides a summation of 12 articulatory recording methods, forming a tool to be used by researchers in identifying which method of recording is appropriate for their work. After addressing the cost and resource-intensive limitations of existing methods, a new system of modelling is proposed that leverages external to internal correlation modelling techniques to create a more efficient models of the oral cavity. The vision is that the outcomes will be applicable to a broad spectrum of oral functions related to physiology, health and wellbeing, including speech, oral processing of foods as well as dental health. The applications may span from speech correction, designing foods for the aging population, whilst in the dental field we would be able to gain information about patient's oral actions that would become part of creating a personalised dental treatment plan.

Prosocial speech acts: Links to pragmatics and aging.

This study investigated how adults over the lifespan flexibly adapt their use of prosocial speech acts when conveying bad news to communicative partners. Experiment 1a (N = 100 Scottish adults aged 18-72 years) assessed whether participants' use of prosocial speech acts varied according to audience design considerations (i.e., whether or not the recipient of the news was directly affected). Experiment 1b (N = 100 Scottish adults aged 19-70 years) assessed whether participants adjusted for whether the bad news was more or less severe (an index of general knowledge). Younger adults displayed more flexible adaptation to the recipient manipulation, while no age differences were found for severity. These findings are consistent with prior work showing age-related decline in audience design but not in the use of general knowledge during language production. Experiment 2 further probed younger adults (N = 40, Scottish, aged 18-37 years) and older adults' (N = 40, Scottish, aged 70-89 years) prosocial linguistic behavior by investigating whether health (vs. nonhealth-related) matters would affect responses. While older adults used prosocial speech acts to a greater extent than younger adults, they did not distinguish between conditions. Our results suggest that prosocial linguistic behavior is likely influenced by a combination of differences in audience design and communicative styles at different ages. Collectively, these findings highlight the importance of situating prosocial speech acts within the pragmatics and aging literature, allowing us to uncover the factors modulating prosocial linguistic behavior at different developmental stages. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Decreased salivary alpha-amylase reactivity for excluded young women after a speech task.

Salivary alpha-amylase (sAA) has gained popularity as an easily collected biomarker for sympathetic nervous system activation, and research has shown increases in sAA after completing experimental stress tasks in certain groups. However, recent work suggests that salivary cortisol, another stress biomarker, is suppressed after a speech task among experimentally induced exclusion in young women. The present analysis investigated the sAA response in biologically female undergraduates (n=31) who completed a game of Cyberball and then a speech anticipation task. Results showed that women in the social exclusion experimental group had a greater decrease in sAA compared to young women in the inclusion group after the speech task. Results of this study provide support for stress response suppression in women who have experienced social exclusion. The present findings provide pilot evidence for future, larger studies to advance the tend-and-befriend theory.

Atypical brain lateralization for speech processing at the sublexical level in autistic children revealed by fNIRS.

Autistic children often exhibit atypical brain lateralization of language processing, but it is unclear what aspects of language contribute to this phenomenon. This study employed functional near-infrared spectroscopy to measure hemispheric lateralization by estimating hemodynamic responses associated with processing linguistic and non-linguistic auditory stimuli. The study involved a group of autistic children (N = 20, mean age = 5.8 years) and a comparison group of nonautistic peers (N = 20, mean age = 6.5 years). The children were presented with stimuli with systematically decreasing linguistic relevance: naturalistic native speech, meaningless native speech with scrambled word order, nonnative speech, and music. The results revealed that both groups showed left lateralization in the temporal lobe when listening to naturalistic native speech. However, the distinction emerged between autism and nonautistic in terms of processing the linguistic hierarchy. Specifically, the nonautistic comparison group demonstrated a systematic reduction in left lateralization as linguistic relevance decreased. In contrast, the autism group displayed no such pattern and showed no lateralization when listening to scrambled native speech accompanied by enhanced response in the right hemisphere. These results provide evidence of atypical neural specialization for spoken language in preschool- and school-age autistic children and shed new light on the underlying linguistic correlates contributing to such atypicality at the sublexical level.

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.

Theta oscillations within right dorsolateral prefrontal cortex contribute differently to speech versus limb inhibition.

Evidence suggests that speech and limb movement inhibition are subserved by common neural mechanisms, particularly within the right prefrontal cortex. In a recent study, we found that cathodal stimulation of right dorsolateral prefrontal cortex (rDLPFC) differentially modulated P3 event-related potentials for speech versus limb inhibition. In the present study, we further analyzed these data to examine the effects of cathodal high-definition transcranial direct current stimulation (HD-tDCS) over rDLPFC on frontal theta - an oscillatory marker of cognitive control - in response to speech and limb inhibition, during a Go/No-Go task in 21 neurotypical adults. Electroencephalography data demonstrated that both speech and limb No-Go elicited prominent theta activity over right prefrontal electrodes, with stronger activity for speech compared to limb. Moreover, we found that cathodal stimulation significantly increased theta power over right prefrontal electrodes for speech versus limb No-Go. Source analysis revealed that cathodal, but not sham, stimulation increased theta activity within rDLPFC and bilateral premotor cortex for speech No-Go compared to limb movement inhibition. These findings complement our previous report and suggest (1) right prefrontal theta activity is an amodal oscillatory mechanism supporting speech and limb inhibition, (2) larger theta activity in prefrontal electrodes for speech versus limb following cathodal stimulation may reflect allocation of additional neural resources for a more complex motor task, such as speech compared to limb movement. These findings have translational implications for conditions such as Parkinson's disease, wherein both speech and limb movement are impaired.

Shut-up Toys for Second Language Learners: Impact of Digital Media on Early Adolescents' Private Speech Production in Individual and Collaborative Tasks.

Researchers, parents, and policymakers from previous generations have recently expressed concern about the inevitable exposure of youngsters to digital media and its potentially detrimental effects on their development. Private speech is the overt audible self-talk people produce when engaged with challenging problem-solving tasks and is believed to aid in second language acquisition as reported (Vygotsky in Thought and language, MIT Press, 1962); (Winsler in Private Speech, Executive Functioning, and the Development of Verbal Self-Regulation, 2009). This qualitative case study explored private speech production in three young adolescents (two 11-year-olds and one 10-year-old) while completing an English as a foreign language task (Bingo! game) individually and collaboratively in physical and digital modes. Patterns of participants' private speech markers emerged from a thematic analysis of the transcribed oral interactions during eight sessions. The frequency of occurrence of the participants' private speech markers was reported and interpreted based on the emergent typology to compare collaborative and individual task completion in physical and digital modes. Regardless of the individual or collaborative nature of the task, private speech use decreased during the digital version of the game. However, collaborative tasks evoked more private speech from the participants regardless of modality. The findings of the study suggest digital media usage is likely to hinder private speech production for self-regulatory purposes in young adolescents, even in collaboration with peers.

Attention Drives Visual Processing and Audiovisual Integration During Multimodal Communication.

During communication in real-life settings, our brain often needs to integrate auditory and visual information and at the same time actively focus on the relevant sources of information, while ignoring interference from irrelevant events. The interaction between integration and attention processes remains poorly understood. Here, we use rapid invisible frequency tagging and magnetoencephalography to investigate how attention affects auditory and visual information processing and integration, during multimodal communication. We presented human participants (male and female) with videos of an actress uttering action verbs (auditory; tagged at 58 Hz) accompanied by two movie clips of hand gestures on both sides of fixation (attended stimulus tagged at 65 Hz; unattended stimulus tagged at 63 Hz). Integration difficulty was manipulated by a lower-order auditory factor (clear/degraded speech) and a higher-order visual semantic factor (matching/mismatching gesture). We observed an enhanced neural response to the attended visual information during degraded speech compared to clear speech. For the unattended information, the neural response to mismatching gestures was enhanced compared to matching gestures. Furthermore, signal power at the intermodulation frequencies of the frequency tags, indexing nonlinear signal interactions, was enhanced in the left frontotemporal and frontal regions. Focusing on the left inferior frontal gyrus, this enhancement was specific for the attended information, for those trials that benefitted from integration with a matching gesture. Together, our results suggest that attention modulates audiovisual processing and interaction, depending on the congruence and quality of the sensory input.

Hand Gestures Have Predictive Potential During Conversation: An Investigation of the Timing of Gestures in Relation to Speech.

During face-to-face conversation, transitions between speaker turns are incredibly fast. These fast turn exchanges seem to involve next speakers predicting upcoming semantic information, such that next turn planning can begin before a current turn is complete. Given that face-to-face conversation also involves the use of communicative bodily signals, an important question is how bodily signals such as co-speech hand gestures play into these processes of prediction and fast responding. In this corpus study, we found that hand gestures that depict or refer to semantic information started before the corresponding information in speech, which held both for the onset of the gesture as a whole, as well as the onset of the stroke (the most meaningful part of the gesture). This early timing potentially allows listeners to use the gestural information to predict the corresponding semantic information to be conveyed in speech. Moreover, we provided further evidence that questions with gestures got faster responses than questions without gestures. However, we found no evidence for the idea that how much a gesture precedes its lexical affiliate (i.e., its predictive potential) relates to how fast responses were given. The findings presented here highlight the importance of the temporal relation between speech and gesture and help to illuminate the potential mechanisms underpinning multimodal language processing during face-to-face conversation.

Brain responses to repetition-based rule-learning do not exhibit sex differences: an aggregated analysis of infant fNIRS studies.

Studies have repeatedly shown sex differences in some areas of language development, typically with an advantage for female over male children. However, the tested samples are typically small and the effects do not always replicate. Here, we used a meta-analytic approach to address this issue in a larger sample, combining seven fNIRS studies on the neural correlates of repetition- and non-repetition-based rule learning in newborns and 6-month-old infants. The ability to extract structural regularities from the speech input is fundamental for language development, it is therefore highly relevant to understand whether this ability shows sex differences. The meta-analysis tested the effect of Sex, as well as of other moderators on infants' hemodynamic responses to repetition-based (e.g. ABB: "mubaba") and non-repetition-based (e.g. ABC: "mubage") sequences in both anatomically and functionally defined regions of interests. Our analyses did not reveal any sex differences at birth or at 6 months, suggesting that the ability to encode these regularities is robust across sexes. Interestingly, the meta-analysis revealed other moderator effects. Thus in newborns, we found a greater involvement of the bilateral temporal areas compared to the frontal areas for both repetition and non-repetition sequences. Further, non-repetition sequences elicited greater responses in 6-month-olds than in newborns, especially in the bilateral frontal areas. When analyzing functional clusters of HbR timetraces, we found that a larger right-left asymmetry for newborn boys in brain responses compared to girls, which may be interpreted in terms of a larger right-left asymmetry in cerebral blood flow in boys than in girls early in life. We conclude that extracting repetition-based regularities from speech is a robust ability with a well-defined neural substrate present from birth and it does not exhibit sex differences.

Can listeners predict whether or not a stutter follows a stretch of fluent speech?

PURPOSE: Neurophysiological studies report that people who stutter (PWS) exhibit enhanced motor preparation before they stutter. This motor preparation pattern raises the possibility of detecting upcoming stutter moments before they actually occur. This study examined whether these motor preparation differences are detectable by listeners in the corresponding acoustic signal, thereby allowing them to predict upcoming stuttering moments. If so, features in these acoustic patterns could potentially be employed by computational procedures to automate detection of upcoming stutters and to target auditory feedback alterations specifically on these locations. METHODS: Forty healthy normal-hearing participants (aged 18-30) listened to seemingly fluent speech extracts each of which was either followed by a fluent (control condition) or stuttered (experimental condition) moment after the fluent extract. Participants listened to each extract and rated the likelihood of the speaker stuttering on the next word on a scale of 1 (very unlikely) to 7 (very likely) as to whether they thought there was a subsequent stutter. Several measures were made on the speech extracts which were examined either as control requirements to ensure no differences between experimental and control material or as covariates to assess any effects they had on judgments between the two conditions. RESULTS: Listeners gave significantly higher stutter-likelihood ratings for speech originally followed by a stuttered moment although effects were small. CONCLUSIONS: Naive listeners rated speech extracts that were subsequently followed by stuttered moments as more likely to be followed by a stutter than those that were followed by fluent words after the effects of significant covariates were excluded.