Regular rhythmic primes improve sentence repetition in children with developmental language disorder.

Recently reported links between rhythm and grammar processing have opened new perspectives for using rhythm in clinical interventions for children with developmental language disorder (DLD). Previous research using the rhythmic priming paradigm has shown improved performance on language tasks after regular rhythmic primes compared to control conditions. However, this research has been limited to effects of rhythmic priming on grammaticality judgments. The current study investigated whether regular rhythmic primes could also benefit sentence repetition, a task requiring proficiency in complex syntax-an area of difficultly for children with DLD. Regular rhythmic primes improved sentence repetition performance compared to irregular rhythmic primes in children with DLD and with typical development-an effect that did not occur with a non-linguistic control task. These findings suggest processing overlap for musical rhythm and linguistic syntax, with implications for the use of rhythmic stimulation for treatment of children with DLD in clinical research and practice.

When Visual Cues Do Not Help the Beat: Evidence for a Detrimental Effect of Moving Point-Light Figures on Rhythmic Priming.

Rhythm perception involves strong auditory-motor connections that can be enhanced with movement. However, it is unclear whether just seeing someone moving to a rhythm can enhance auditory-motor coupling, resulting in stronger entrainment. Rhythmic priming studies show that presenting regular rhythms before naturally spoken sentences can enhance grammaticality judgments compared to irregular rhythms or other baseline conditions. The current study investigated whether introducing a point-light figure moving in time with regular rhythms could enhance the rhythmic priming effect. Three experiments revealed that the addition of a visual cue did not benefit rhythmic priming in comparison to auditory conditions with a static image. In Experiment 1 (27 7-8-year-old children), grammaticality judgments were poorer after audio-visual regular rhythms (with a bouncing point-light figure) compared to auditory-only regular rhythms. In Experiments 2 (31 adults) and 3 (31 different adults), there was no difference in grammaticality judgments after audio-visual regular rhythms compared to auditory-only irregular rhythms for either a bouncing point-light figure (Experiment 2) or a swaying point-light figure (Experiment 3). Comparison of the observed performance with previous data suggested that the audio-visual component removed the regular prime benefit. These findings suggest that the visual cues used in this study do not enhance rhythmic priming and could hinder the effect by potentially creating a dual-task situation. In addition, individual differences in sensory-motor and social scales of music reward influenced the effect of the visual cue. Implications for future audio-visual experiments aiming to enhance beat processing, and the importance of individual differences will be discussed.

Atypical beta power fluctuation while listening to an isochronous sequence in dyslexia.

OBJECTIVE: Developmental dyslexia is a reading disorder that features difficulties in perceiving and tracking rhythmic regularities in auditory streams, such as speech and music. Studies on typical healthy participants have shown that power fluctuations of neural oscillations in beta band (15-25 Hz) reflect an essential mechanism for tracking rhythm or entrainment and relate to predictive timing and attentional processes. Here we investigated whether adults with dyslexia have atypical beta power fluctuation. METHODS: The electroencephalographic activities of individuals with dyslexia (n = 13) and typical control participants (n = 13) were measured while they passively listened to an isochronous tone sequence (2 Hz presentation rate). The time-frequency neural activities generated from auditory cortices were analyzed. RESULTS: The phase of beta power fluctuation at the 2 Hz stimulus presentation rate differed and appeared opposite between individuals with dyslexia and controls. CONCLUSIONS: Atypical beta power fluctuation might reflect deficits in perceiving and tracking auditory rhythm in dyslexia. SIGNIFICANCE: These findings extend our understanding of atypical neural activities for tracking rhythm in dyslexia and could inspire novel methods to objectively measure the benefits of training, and predict potential benefit of auditory rhythmic rehabilitation programs on an individual basis.

A stimulus-brain coupling analysis of regular and irregular rhythms in adults with dyslexia and controls.

When listening to temporally regular rhythms, most people are able to extract the beat. Evidence suggests that the neural mechanism underlying this ability is the phase alignment of endogenous oscillations to the external stimulus, allowing for the prediction of upcoming events (i.e., dynamic attending). Relatedly, individuals with dyslexia may have deficits in the entrainment of neural oscillations to external stimuli, especially at low frequencies. The current experiment investigated rhythmic processing in adults with dyslexia and matched controls. Regular and irregular rhythms were presented to participants while electroencephalography was recorded. Regular rhythms contained the beat at 2 Hz; while acoustic energy was maximal at 4 Hz and 8 Hz. These stimuli allowed us to investigate whether the brain responds non-linearly to the beat-level of a rhythmic stimulus, and whether beat-based processing differs between dyslexic and control participants. Both groups showed enhanced stimulus-brain coherence for regular compared to irregular rhythms at the frequencies of interest, with an overrepresentation of the beat-level in the brain compared to the acoustic signal. In addition, we found evidence that controls extracted subtle temporal regularities from irregular stimuli, whereas dyslexics did not. Findings are discussed in relation to dynamic attending theory and rhythmic processing deficits in dyslexia.

Rhythmic and textural musical sequences differently influence syntax and semantic processing in children.

Effects of music on language processing have been reported separately for syntax and for semantics. Previous studies have shown that regular musical rhythms can facilitate syntax processing and that semantic features of musical excerpts can influence semantic processing of words. It remains unclear whether musical parameters, such as rhythm and sound texture, may specifically influence different components of linguistic processing. In the current study, two types of musical sequences (one focusing on rhythm and the other focusing on sound texture) were presented to children who were requested to perform a syntax or a semantic task thereafter. The results revealed that rhythmic and textural musical sequences differently influence syntax and semantic processing. For grammaticality judgments, children's performance was better after regular rhythmic sequences than after textural sound sequences. In the semantic evocation task, children produced more numerous and more various concepts after textural sound sequences than after regular rhythmic sequences. These results suggest that rhythm boosts perceptual and cognitive sequencing required in syntax processing, whereas texture promote verbalization and concept activation in verbal production. The findings have implications for the interpretation of musical priming effects and are discussed in the frameworks of dynamic attending and conceptual processing.

Regular rhythmic primes boost P600 in grammatical error processing in dyslexic adults and matched controls.

Regular musical rhythms orient attention over time and facilitate processing. Previous research has shown that regular rhythmic stimulation benefits subsequent syntax processing in children with dyslexia and specific language impairment. The present EEG study examined the influence of a rhythmic musical prime on the P600 late evoked-potential, associated with grammatical error detection for dyslexic adults and matched controls. Participants listened to regular or irregular rhythmic prime sequences followed by grammatically correct and incorrect sentences. They were required to perform grammaticality judgments for each auditorily presented sentence while EEG was recorded. In addition, tasks on syntax violation detection as well as rhythm perception and production were administered. For both participant groups, ungrammatical sentences evoked a P600 in comparison to grammatical sentences and its mean amplitude was larger after regular than irregular primes. Peak analyses of the P600 difference wave confirmed larger peak amplitudes after regular primes for both groups. They also revealed overall a later peak for dyslexic participants, particularly at posterior sites, compared to controls. Results extend rhythmic priming effects on language processing to underlying electrophysiological correlates of morpho-syntactic violation detection in dyslexic adults and matched controls. These findings are interpreted in the theoretical framework of the Dynamic Attending Theory (Jones, 1976, 2019) and the Temporal Sampling Framework for developmental disorders (Goswami, 2011).