Brain and Language最新文献

Cross-linguistically, nonword repetition (NWR) tasks have been found to differentiate between typically developing (TD) children and those with Developmental Language Disorder (DLD), even when second-language TD (L2-TD) children are considered. This study examined such group differences in Cantonese. Fifty-seven age-matched children (19 monolingual DLD (MonDLD); 19 monolingual TD (MonTD); and 19 L2-TD) repeated language-specific nonwords with varying lexicality levels and Cantonese-adapted quasi-universal nonwords. At whole-nonword level scoring, on the language-specific, High-Lexicality nonwords, MonDLD scored significantly below MonTD and L2-TD groups which did not differ significantly from each other. At syllable-level scoring, the same pattern of group differentiation was found on quasi-universal nonwords. These findings provide evidence from a typologically distinct and understudied language that NWR tasks can capture significant TD/DLD group differences, even for L2-Cantonese TD children with reduced language experience. Future studies should compare the performance of an L2-DLD group and evaluate the sensitivity and specificity of Cantonese NWR.

Brain asymmetries are hypothesized to reduce functional duplication and thus have evolutionary advantages. The goal of this study was to examine whether early brain lateralization contributes to skill development within the speech-language domain. To achieve this goal, 25 infants (2–13 months old) underwent behavioral language examination and fMRI during sleep while listening to forward and backward speech, and then were assessed on various language skills at 55–69 months old. We observed that infant functional lateralization of the superior temporal gyrus (STG) for forward > backward speech was associated with phonological, vocabulary, and expressive language skills 4 to 5 years later. However, we failed to observe that infant language skills or the anatomical lateralization of STG were related to subsequent language skills. Overall, our findings suggest that infant functional lateralization of STG for speech perception may scaffold subsequent language acquisition, supporting the hypothesis that functional hemisphere asymmetries are advantageous.

Transcranial direct current stimulation (tDCS) targeting Broca’s area has shown promise for augmenting language production in post-stroke aphasia (PSA). However, previous research has been limited by small sample sizes and inconsistent outcomes. This study employed a double-blind, parallel, randomized, controlled design to evaluate the efficacy of anodal Broca’s tDCS, paired with 20-minute speech and language therapy (SLT) focused primarily on expressive language, across 5 daily sessions in 45 chronic PSA patients. Utilizing the Western Aphasia Battery-Revised, which assesses a spectrum of linguistic abilities, we measured changes in both expressive and receptive language skills before and after intervention. The tDCS group demonstrated significant improvements over sham in aphasia quotient, auditory verbal comprehension, and spontaneous speech. Notably, tDCS improved both expressive and receptive domains, whereas sham only benefited expression. These results underscore the broader linguistic benefits of Broca’s area stimulation and support the integration of tDCS with SLT to advance aphasia rehabilitation.

We investigated how neural oscillations code the hierarchical nature of stress rhythms in speech and how stress processing varies with language experience. By measuring phase synchrony of multilevel EEG-acoustic tracking and intra-brain cross-frequency coupling, we show the encoding of stress involves different neural signatures (delta rhythms = stress foot rate; theta rhythms = syllable rate), is stronger for amplitude vs. duration stress cues, and induces nested delta-theta coherence mirroring the stress-syllable hierarchy in speech. Only native English, but not Mandarin, speakers exhibited enhanced neural entrainment at central stress (2 Hz) and syllable (4 Hz) rates intrinsic to natural English. English individuals with superior cortical-stress tracking capabilities also displayed stronger neural hierarchical coherence, highlighting a nuanced interplay between internal nesting of brain rhythms and external entrainment rooted in language-specific speech rhythms. Our cross-language findings reveal brain-speech synchronization is not purely a “bottom-up” but benefits from “top-down” processing from listeners’ language-specific experience.