Gesture serves as a foundational modality for conveying event structure, providing critical visual information about transitivity and participant roles. Sign languages integrate manual (hand-based) and non-manual (face, torso, head) articulations to encode complex linguistic information. Among these, mouth movements provide phonological and lexical cues, but their role in sign-naïve individuals remains underexplored. This study investigates how sign-naïve individuals process non-manual markers (mouthings) in unfamiliar signed verbs, to explore how linguistic information is extracted from visual stimuli sharing properties with both gesture and sign language. Using EEG, we examined whether lip-reading functions as a linguistic cue or a general perceptual enhancement in non-signers viewing Austrian Sign Language (ÖGS) and non-ÖGS stimuli. Findings reveal distinct neural signatures for manual signs presented with and without congruent mouthings. An early posterior negativity followed by a late posterior positivity suggests that mouthings facilitate lexical access by providing phonological cues that activate stored lexical representations. Conversely, stimuli without mouthings elicited increased anterior activity, reflecting heightened cognitive control demands. Further, telic verbs, which inherently encode event endpoints, showed earlier and stronger facilitation from congruent mouthings compared to atelic verbs. These findings align with the Event Visibility Hypothesis and reinforce the role of visual cues in linguistic comprehension.
Subtle language changes occur early in Alzheimer's disease (AD). Early detection of these changes therefore represents a potential tool for the early detection of individuals who could develop the disease. Knowledge on connected speech (CS) in Subjective Cognitive Decline (SCD, a preclinical stage of AD for at least some individuals, characterized by cognitive complaints without objective cognitive deficits), remains limited. In this study, we used network analysis to examine the relationships between CS features extracted with Natural Language Processing techniques. This method allowed us to determine whether the patterns emerging from the SCD CS network (i.e., a network modelling the relationships between CS features) differed from those observed in similar networks constructed for controls and individuals with Mild Cognitive Impairment (MCI, a prodromal stage of AD for many individuals, characterized by objective cognitive deficits but preserved daily functioning). We found minimal differences between individuals with SCD and controls and individuals with MCI in raw CS features. Nevertheless, our network analysis revealed a stronger relative subdivision of the SCD network into different dimensions (representing linguistic domains), as well as relative reductions in within-dimension density and between-dimension strength compared to the Control and MCI networks. There were also relative differences in how the CS features forming the Semantic conciseness and Lexical and syntactic complexity dimensions associated with other features in the SCD network. Results suggest that network analysis might be more sensitive than other methods to subtle CS differences in SCD and that this population might use distinct CS production mechanisms.
Preterm birth represents a risk for vulnerability across neurodevelopmental domains. However, its impact on early communication and cross-domain associations remains underexplored. This study compared preterm and full-term infants at 18 months on communicative, cognitive, linguistic, and motor abilities, and examined associations between pointing and these skills. Thirty-nine preterm and 28 full-term infants participated. Pointing (hand, index), vocal productions (vocalizations, babbling, words), and expression modalities (unimodal gestural, unimodal vocal, bimodal gestural-vocal) were elicited using the “decorated room” task and coded with ELAN. Cognitive, language (receptive, expressive), and motor (fine, gross) abilities were assessed with the BSID-III. Preterm infants produced fewer index points, babbling, and bimodal expressions, and showed lower scores across all BSID-III scales. Only in preterm infants, index pointing significantly correlated with developmental scores, particularly cognitive and fine-motor ones. Findings highlight interconnected cross-domain developmental trajectories in the preterm population, with index pointing as a key developmental marker at 18 months.
Auditory and speech-perception difficulties are common in post-stroke aphasia (PSA), but cortical responses during passive listening to Mandarin speech remain underexplored. Seventeen Mandarin-speaking individuals with PSA and 18 matched healthy controls listened to auditory oddball blocks containing /ba/ standards and /pa/ deviants during functional near-infrared spectroscopy (fNIRS). Although these syllables instantiate an aspiration contrast strongly cued by voice onset time (VOT), standard and deviant trials were combined within a single block-level condition. The resulting measures therefore indexed activation during speech-containing blocks relative to silent inter-block intervals rather than phonemic discrimination, categorization, or VOT-specific processing. Seven theory-driven channels covering bilateral auditory, sensorimotor, inferior frontal, and dorsolateral prefrontal regions were analyzed using three HbO indices: β coefficient, peak amplitude, and temporal centroid. The PSA group showed an overall reduction in task-related HbO activation, reflected by a significant Group effect for the β coefficient. Peak amplitude also showed significant Group and Group × Channel effects, although no individual channel remained significant after correction for multiple comparisons. Temporal centroid showed no significant group or interaction effects. These findings provide preliminary evidence for reduced block-evoked cortical recruitment during passive auditory exposure to Mandarin speech sounds in PSA. Because the analysis did not include a direct standard–deviant or active auditory control comparison, the findings do not establish a selective impairment of phonemic discrimination, categorization, or VOT processing. Because patients were assessed 6–7 months after stroke onset, the activation differences may reflect both persistent impairment and recovery-related reorganization during the early chronic stage.
