Annals of the New York Academy of Sciences

In non-verbal communication, observers infer emotions from visible facial movements, yet emotional experiences are described in internal bodily terms (e.g., "my heart skipped a beat"). This contrast highlights a tension between external sensory cues and internal signals. In this context, we examined an overlooked gap in affective science: what makes an emotional portrayal believable, and do believability judgments reflect only what observers can see or also the portraying person's internal cardiac dynamics? To test this, we created 311 scenario-driven acting clips designed to avoid prototypical posed displays. For each clip, we quantified facial movement magnitude from the video, recorded ECG during preparation and enactment, and collected actors' self-reports. Online participants (N = 371) viewed these clips and provided emotion recognition responses and continuous ratings of believability, valence, or arousal. The results show that believability decreased as movement magnitude increased, with a non-linear relationship indicating a stronger penalty as motion increased. Valence further shaped this pattern, with increasing movement reducing believability more strongly for portrayals with negative valence. This effect persisted after accounting for intended emotion, perceived arousal, and emotion recognizability. Cardiac dynamics varied during performance, and actors' higher heart rate variability was associated with higher believability for positively valenced portrayals. Together, these findings show that believability is driven by visible movement cues interpreted in relation to valence, with actors' cardiac dynamics showing selective alignment with believability. These results identify core components of believable emotional expressions and provide a basis for studying such judgments in everyday social interaction.

Empathy enables individuals to attune to others' experiences through shared affective, sensorimotor, and neural representations, but its influence on higher-level decision-making and social alignment remains unknown. We examined whether empathy promotes social conformity and whether this effect depends on physiological arousal, visual attention, and socio-emotional traits. Seventy-three participants completed an empathy-for-pain task followed by a modified random-dot task in which they interacted with previously seen empathy targets, while physiological signals and eye movements were recorded. Drift-diffusion modeling showed that feedback from empathy targets increased conformity, reflected in stronger decision bias toward targets, faster evidence accumulation, and reduced decision conservatism. Visual attention to the eyes or mouth was linked to greater conformity depending on the context. Heart rate variability was unrelated to conformity, whereas phasic skin conductance was associated with smaller bias changes and greater conservatism. Alexithymia and autistic traits further shaped the empathy-conformity relationships. These findings suggest that empathic shared representation extends beyond affective resonance to influence social alignment in decision-making.

Rhythm perception ability underpins music and language processing, and its developmental origins trace back to the earliest periods of life. While most rhythm patterns contain a variety of inter-onset intervals, listeners typically extract a steady underlying beat periodicity, as well as beat grouping periodicities (groups of two or three beats will be at frequencies 1/2 or 1/3, respectively, of that of the primary beat), forming a metrical hierarchy. While the developing brain can track auditory rhythm before birth, a previous study found that neural sensitivity to faster beat-related periodicities emerges early in third trimester of gestation, whereas encoding of slower metrical structure periodicities only appears closer to term birth. However, as rhythm patterns were only presented at one tempo, neural sensitivity to metrical structure could not be disentangled from sensitivity to tempo during early development. Thus, here we presented auditory rhythmic sequences at two different tempi and used high-resolution electroencephalography to measure neural sensitivity to their encoding in full-term newborns and young adults. Adults demonstrated a similar sensitivity to metrical structure across tempi, with greatest response at the duple metrical frequency regardless of tempo. Newborn neural responses, by contrast, were tempo-dependent, displaying markedly different response patterns across beat and meter frequencies at the different tempi. Together, these results reveal that tempo and metrical structure interact in shaping how the neonatal brain encodes auditory rhythm, suggesting that early neural processing may be constrained in its ability to track slower periodicities, and highlighting a developmental shift in the relative contributions of tempo and metrical structure to rhythmic processing.

Speech and music consistently differ in their acoustic rhythms, despite the cross-cultural diversity in their surface forms. Here, we investigate whether speech and music rhythms are rooted in distinct intrinsic timescales of the sensorimotor system, which are separately recruited to support individual communication and group synchronization, respectively. Corpus analysis revealed that the timescales dominating speech (4-8 Hz) and music rhythms (< 2 Hz) separately emerge in infant laughter, babbling and cries, and that both speech and song rhythms mature at about age three. The functional division between the two timescales is further probed through sensorimotor synchronization experiments, in which participants vocalize or tap to sound sequences presented at different rates. The rhythm produced by individuals is strongest between 4 and 8 Hz. In contrast, the produced rhythm is best synchronized among participants below 2 Hz. Collectively, these findings reveal two characteristic timescales in the human sensorimotor system, i.e., a faster (4-8 Hz) timescale reflecting resonance in individual production and a slower (<2 Hz) timescale that fosters interpersonal synchronization. The two timescales provide plausible biological basis for the rhythms of speech and music.

Music enjoyment and familiarity are closely related but often confounded in studies of neural music processing. Here, we investigated their distinct contributions to cortical oscillatory activity and neural tracking of music using electroencephalography (EEG). Thirty-two participants listened to self-selected all-time favourite songs, recent favourite songs, and tempo-matched songs from disliked genres. This novel paradigm dissociated familiarity from enjoyment by including highly enjoyed songs that differed in familiarity. Spectral power and cortical tracking (using Mutual Information) were analysed using linear mixed-effects models with enjoyment and familiarity ratings. Familiarity was associated with increased left-frontal alpha power, whereas enjoyment predicted increased theta and beta power, demonstrating distinct oscillatory signatures for these dimensions. An interaction revealed that the positive relationship between enjoyment and theta power was strongest for highly familiar music. Cortical tracking analyses showed that greater enjoyment was associated with reduced delta-band tracking, with a significant interaction indicating that this negative relationship was present for highly familiar songs but not for less familiar songs. These findings indicate that enjoyment and familiarity differentially shape neural responses to music and highlight the importance of modelling both factors to disentangle their distinct effects on neural activity during music listening.

Social disconnection (i.e., loneliness and social isolation) poses a severe risk to health and is particularly prevalent among older adults. Qualitative and behavioural evidence suggests that intergenerational social interactions can mitigate social disconnection by offering opportunities for adults to form new social connections, yet the neurophysiological and kinematic processes underpinning relationship formation remain poorly understood. This article presents and validates the InterGenSynchrony Dataset -- a longitudinal, multimodal hyperscanning dataset acquired during a 6-session program, where 30 same generation and 31 intergenerational dyads met as strangers and became acquainted through creative drawing. The dataset includes dyads' concurrent recordings of brain activity (i.e., fNIRS hyperscanning), motion capture, self-report measures including loneliness, collaborative behavioural scores, drawings (artefacts of collaboration), subjective experiences in text and interview forms. This dataset is optimised for multimodal investigations into the neural, physiological, behavioural, kinematic, and subjective aspects of relationship formation within and between generations in a real-world setting.

Successful communication depends not just on what we say but also on how we repair it when understanding breaks down. People routinely respond to misunderstanding by gesturing more or speaking louder. Yet whether these responses actually reflect measurable bodily effort, and whether it helps communication, has not yet been directly tested. Extending the hypo- and hyper-articulation accounts to whole-body multimodal communication we ask: does regaining understanding require increased physical effort, and does that effort improve communicative outcomes? In a pre-registered biomechanical study, 61 pairs of participants conveyed concepts without conventionalized language, using gestures, vocalizations, or both, and repaired failed attempts. We measured communicative effort by capturing arm torque change (upper-limb effort), vocal amplitude (vocal effort), and postural adjustments (postural effort). Using Bayesian hierarchical models, we show that repair increases physical effort across all three measurements, but that performers communicate more over time rather than more forcefully at any particular moment in time. Upper-limb effort scale with the degree of misunderstanding but effort overall does not predict whether communication succeeds. We suggest that communicative effort on the level we measured here functions as an index of continued commitment rather than a mechanism for repairing misunderstanding.

Background: Gut injury after pediatric cardiac surgery remains an ongoing challenge, resulting in increased morbidity and mortality for children with congenital heart disease (CHD) and a significant burden on the healthcare system. It remains unclear what the driving forces are that result in this pro-inflammatory state following pediatric cardiac surgery with cardiopulmonary bypass. Understanding key components involved in the gut composition, gut barrier function, and systemic inflammation in children with CHD after cardiac surgery is critical to improve outcomes. Methods: A prospective study of patients aged 0-5 years with CHD undergoing cardiac surgery (CPB group) or non-CHD undergoing non-cardiac surgery (Comparison group). We collected pre-operative and post-operative stool and plasma to evaluate the microbiome, metabolites, markers of gut barrier function, and inflammatory cytokines. Clinical variables were collected to evaluate markers of inflammation. These variables were compared between the two groups to evaluate signatures and develop unique biomarker profiles. Results: We enrolled 62 patients (CPB, n=46; Comp, n=16). CPB patients had increased pro-inflammatory microbiota and reduced diversity metrics pre-operatively, which were exacerbated post-operatively. The CPB group also had increased pro-inflammatory eicosanoids and reduced gut and heart protective short-chain fatty acids versus the Comparison group. The CPB group had increased pro-inflammatory and reduced anti-inflammatory cytokines post-operatively. The CPB group also had increased markers of gut barrier dysfunction versus the Comparison group. Mediation analysis showed the microbial functional shift was associated with increased PGE2 and reduced butyric acid in the CPB group, associated with increased cytokines and clinical markers of inflammation post-operatively. Conclusion: We demonstrate unique gut microbial and metabolites profiles associated with gut permeability and systemic inflammation in children with CHD undergoing cardiac surgery highlighting a unique microbiome-inflammation axis in this patient population. Further studies to evaluate causal links with these profiles will identify potential targets to improve outcomes for these patients.

Antimicrobial resistance constitutes a major threat to global public health. Among emerging extensively drug-resistant bacteria (eXDR), carbapenemase-producing Enterobacteriaceae (CPE) expose hospitals to outbreaks through rapid dissemination, and to therapeutic limitations. Through a mixed epidemiological-qualitative methods study, we report the most extensive CPE carriage outbreak known to date in France, which occurred at Hopital Europeen Marseille (HEM) between January and June 2025. By the end of November 2024, the admission of an index patient returning from Senegal carrying an NDM-producing Escherichia coli led to an extensive transmission, despite adherence to national screen and isolate guidelines. More than 7,500 rectal screening tests evidenced 481 CPE carriers (including 343 NDM, 129 OXA-48-like and 9 other CPE), and 14 vancomycin-resistant Enterococcus faecium carriers. This major outbreak conducted to a phenomenal involvement of clinical, technical and administrative teams within the institution. It highlighted operational limitations in current screening, cohorting and biocleaning strategies in the context of hospital-wide outbreak. We describe the outbreak trajectory, the control measures implemented and provide a structured synthesis of lessons learned across organisational, scientific and policy domains.

Background Klebsiella pneumoniae (Kpn) is a major cause of neonatal sepsis in Africa. 3rd generation cephalosporin and gentamicin resistant Kpn is the norm in many sites, rendering WHO recommended first- and second-line antimicrobials ineffective. An understanding of which neonates and infants are most at risk of sepsis caused by Kpn would support the case for improved access to WHO watch and reserve antimicrobials (i.e. carbapenems) for patients most likely to benefit from them. Methods A prospective case-control study was conducted at Queen Elizabeth Central Hospital, Malawi. Cases were infants <3 months of age with blood or CSF culture confirmed Kpn infection. Controls were healthy infants from the same wards and were matched 2:1. Univariate and multivariate logistic regression were performed on mean-centred data to determine risk factors for infection with Kpn. Results We analysed data from 38 cases and 76 controls between August 2021 and April 2023. Mortality at 3 months of age was 21/38 (29%) for cases, with 14/38 (37%) identified postmortem and 6/76 (7.9%) for controls (OR 14.0 (95% CI 4.59, 49.2, p>0.001). Cases were more likely to be born out of QECH than controls (42% vs. 24%, p = 0.043), and cases had lower birthweights (median 2200g vs. 2850g, p = 0.005). Multivariate logistic regression analysis revealed that increasing birthweight was protective against Kpn infection (OR: 0.858 [95% CI: 0.745, 0.987] per 100g increase), while longer hospital stay was associated with increased odds of infection (OR: 1.148 [95% CI: 1.012, 1.1.303] per additional day). Most infecting isolates (34/38 [89%]) were resistant to first- and second-line antimicrobial agents, but all were sensitive to meropenem and 33/36 [92%] to amikacin. Conclusion Low birthweight infants with prolonged hospital stay were at greatest risk of Kpn infections that were typically resistant to WHO first- and second-line antimicrobial therapy. These infants should be prioritised for antibiotics that have the potential to be life-saving. The overlapping and evolving nature of these risk factors makes it difficult to design a simple tool to support empiric initiation of meropenem. Neonates critically ill with Kpn sepsis cannot, however, afford to wait for blood culture confirmation before receiving effective treatment. This highlights the need for empiric decision making frameworks that allow rapid initiation of effective therapy in high-risk neonates.

Digital technologies can support meaningful social interaction by providing personally relevant prompts for memory, communication, and shared reflection. In later life, mobile phone photography may offer an accessible medium through which older adults and caregivers construct stories, express meaning, and participate in relational engagement. However, limited psychophysiological evidence is available on how digital photo supported storytelling engages cognitive and social processes in older adult caregiver dyads. This study examined alpha band EEG dynamics during digital photo elicited storytelling in two museum settings. Thirty two older adult caregiver dyads completed cognitive and psychological screening and participated in a museum-based storytelling protocol. During the museum visit, participants used mobile-phone photography to capture personally meaningful objects, scenes, or exhibition spaces. Each participant then selected one photograph as a digital prompt for a structured but naturalistic storytelling interaction. EEG was recorded during eyes closed resting, eyes open resting, storytelling, and listening conditions. Relative alpha power was analyzed using a predefined 10 electrode sensor level set. Task related alpha modulation was examined relative to eyes open resting. Associations between Cz alpha power and MoCA scores were tested, and dyad level alpha band inter brain similarity was explored using spatial alpha power patterns with within site shuffled dyad surrogate comparisons. Alpha power was higher during eyes closed resting and lower during storytelling and listening relative to eyes-open resting, indicating task-related alpha modulation during digital photo supported narrative interaction. Associations between MoCA scores and Cz alpha power were weak, condition-specific, and did not survive false discovery rate correction. During storytelling, dyad level alpha-band inter brain similarity was modestly higher than within site shuffled dyad estimates, but this effect did not remain significant after correction across conditions. These findings suggest that digital photo elicited storytelling can provide a meaningful medium for studying cognitive and social engagement in older adult caregiver dyads. Alpha band EEG activity was sensitive to storytelling and listening, although cognition related and dyadic similarity effects were modest. The study contributes to research on technology supported human behavior by showing how digital image prompts can structure naturalistic social interaction while enabling psychophysiological measurement in real-world contexts.

PurposeInterpersonal entrainment, defined as the tendency of interacting individuals to temporally align their behaviours, is considered a key mechanism supporting social interactions through predictive and multisensory processes. Autism Spectrum Disorder (ASD), characterized by social and communication difficulties, has been associated with atypical predictive and multisensory integration processes, which may affect spontaneous entrainment to others actions during rhythmic interactions. MethodsThe present study investigated spontaneous interpersonal entrainment in 24 autistic and 22 neurotypical young adults using a unidirectional adaptation of the drifting metronomes paradigm developed by Rosso et al. (2021). Participants synchronized their finger tapping with an auditory metronome while either seeing or not seeing a partners hand movements performing the same task at a slightly different tempo. Individual synchronization performance was assessed using asynchrony measures and computational modelling of sensorimotor synchronization, while interpersonal coordination dynamics were quantified using joint recurrence analysis. ResultsVisual exposure to the partners hand movements significantly increased tapping variability while simultaneously enhancing spontaneous interpersonal entrainment. Contrary to previous findings, these effects were comparable across groups, suggesting similar sensitivity to spontaneous low-level interpersonal coupling under stable and predictable conditions. ConclusionOverall, the findings support accounts proposing selective rather than generalized atypicalities in predictive processing and interpersonal entrainment in ASD.

Advanced footwear technology (AFT) improves running economy and is widely credited with recent performance improvements in road running, with observational analyses consistently demonstrating that women have improved more than men. In contrast, laboratory studies generally report similar running economy responses to AFT in both sexes, leaving the observational-experimental divergence unresolved. A fundamental limitation of observational work is the absence of a control condition, making it impossible to separate AFT-related gains from concurrent performance trends. We addressed this by comparing performances between pre-AFT (2009-2015) and AFT (2017-2024) eras across road-running events (10km, half marathon, marathon) and throwing events (shot put, discus, javelin, hammer), the latter serving as an active control condition subject to the same broad athletic trends but unaffected by footwear technology. The top 50 performances per event, era, and sex were converted to World Athletics points and analysed using linear mixed-effects models. Performances improved significantly between eras ({beta} = 0.294, p < .001), with gains substantially larger in road running than in throwing ({beta} = 0.731, p < .001). The sex-specific pattern of improvement also differed between event categories (era x event type x sex interaction, {beta} = 0.786, p < .001): road-running improvements were greater in women than men (4.51% vs 2.62%), whereas throwing improvements did not differ by sex (0.93% vs 1.14%). These findings suggest that AFT benefits women more than men in competition, whether through a greater physiological response or more effective translation of economy gains to race performance, and suggest current laboratory protocols may be insufficiently sensitive to detect potential sex-specific effects.

Aphasia diagnosis in Indonesia remains challenging due to limited culturally and linguistically appropriate instruments. Widely used tools such as the Boston Diagnostic Aphasia Examination (BDAE) and Western Aphasia Battery (WAB) are not adapted to the Indonesian context, while Tes Afasia untuk Diagnosis, Informasi, dan Rehabilitasi (TADIR) provides screening but lacks diagnostic accuracy. To address this gap, we developed the Instrumen Diagnosis dan Evaluasi Afasia (IDEA) for native Indonesian speakers and evaluated its validity, reliability, and normative cutoff values in cognitively healthy Indonesian adults. Eighty-three cognitively normal adults (screened using MoCA-Ina) with no history of neurological disease were assessed using IDEA, which evaluates six language domains. Items were adapted from existing tools and reviewed by experts. Content validity, internal consistency (Cronbachs alpha), and construct validity (Exploratory Factor Analysis) were analyzed using SPSS v25. A total of 83 participants were included (median age = 55.81 years, 54% secondary education). IDEA demonstrated good feasibility, with an average completion time of 45-60 minutes depending on participant engagement. Content validity was established by unanimous expert consensus. Construct validity showed meritorious sampling adequacy (KMO = .872) and significant sphericity (Bartletts test {chi}^2 (15) = 278.523, p<.001), supporting factor analysis. Internal consistency showed good reliability across six domains (Cronbachs = 0.896). IDEA is a valid and reliable tool for assessing aphasia in Indonesian natives. It is a culturally appropriate assessment tool which offers structured, domain-based evaluation and supports differential diagnosis of both classical and progressive aphasia syndromes. Keywords: Aphasia, Language Assessment, Indonesian, IDEA, Validity

Background & Objective. Cardiac rehabilitation is an existing guideline-concordant intervention for heart failure that provides benefits but is grossly underutilized by both physicians and patients. We aimed to identify patient-reported barriers and facilitators of participation in cardiac rehabilitation. Design, participants, approach: Qualitative theory-guided in-depth interviews were conducted with adults with heart failure, recruited from ambulatory settings with oversampling of those with heart failure with preserved ejection fraction. Thematic analysis was applied to interview data. Depressive symptoms and perceived stress were assessed by Patient Health Questionnaire (PHQ-8) and Perceived Stress Scale (PSS), respectively. Key results: Twenty-two adults with heart failure, aged 27-85, completed the study; of them 59.1% were women, 68.2% - African American, 4.5% - Hispanic; 77.3% had public insurance or were self-pay; 68.2% had heart failure with preserved ejection fraction. Mean PHQ-8 score was 11.4 (SD= 2.9) and mean PSS score - 20.4 (SD=4.5). Patient-reported barriers to cardiac rehabilitation included unawareness of cardiac rehabilitation and its benefits, perceived inability to exercise, depression, and weight gain, specifically for heart failure with preserved ejection fraction. Perceived inability to exercise stemmed from uncontrolled heart failure symptom burden and exercise intolerance, medication side effects, non-cardiac pain, fear of exercise, and low motivation for exercise. Facilitators of participation included intrinsic and extrinsic motivating factors and specific features of programs, such as individualized and supervised interventions with moderate level of exercise. Conclusion: Participants reported multiple barriers to cardiac rehabilitation; some of them can be modified by providing counselling and referral to cardiac rehabilitation from primary care physicians and simultaneously addressing heart failure symptom burden, pain, stress and depression. Combining cardiac rehabilitation and weight management can benefit adults with heart failure with preserved ejection fraction specifically. Increasing insurance coverage for cardiac rehabilitation for heart failure is warranted.

Background. Given uncertainty about whether later-life health at similar ages is improving over time, we examined trends across multiple health domains. Methods. We analysed data from community-dwelling adults aged 50 and older in the English Longitudinal Study of Ageing in 2004/05, 2012/13, and 2023/24 (main survey: N=8389, 8549, and 6090, respectively). Outcomes included self-rated health, limiting long-standing illness, pain, mobility limitations, cardiometabolic and chronic conditions, obesity, inflammation, mental health, quality of life and memory. Weighted pooled modified Poisson and linear regressions compared outcomes over time, overall, and by age group and education, with additional adjustment for sex and wealth. Results. Adjusted estimates showed divergent trends. Fair/poor self-rated health increased from 27% to 34%, and any pain from 37% to 47%, whereas mobility impairments declined from 58% to 52%. Self-reported high cholesterol increased from 19% to 39%, while biomarker-defined high cholesterol declined from 78% to 54%; diabetes increased on both measures. Psychiatric problems increased from 6% to 10%, quality of life declined, and memory improved. However, trends differed by age and education, particularly for limiting long-standing illness, mobility limitations, cholesterol biomarkers, and mental health, indicating that aggregate trends masked unevenly distributed changes. Conclusion. Later-life health in England has not improved uniformly. Gains in functioning, biomarkers, and cognition coexist with rising pain and poorer mental health. Trends were also socially and age patterned, producing increasingly multidimensional and socially patterned health outcomes. Multidomain health monitoring is essential for interpreting population health trends and planning healthy ageing, prevention, long-term care, and work policies.

The marine sponge holobiont, composed of the sponge host and its microbial symbionts, is a known source of abundant and diverse ether lipids (ELs). Apart from their structural role in the cytoplasmic membrane of archaea and some bacteria, ELs have often been linked to signaling functions and defense against pathogens. Despite the relevance of ELs, their biosynthesis, as well as the identity of their producers, remain elusive. Here, we report the analysis of potential ether lipid producing genes and gene clusters, detected in marine sponge metagenomes as well as public sponge genomes. We show that the sponge holobiont has the capacity to synthesize ELs via several pathways, and suggest the ability of the sponge holobiont to synthesize ELs under different O2 levels. Finally, targeted lipidome analysis confirmed that ELs are present in the lipid profiles of all of the studied sponge holobiont samples, and indicates that the biosynthesis of the plasmalogens detected is likely restricted to the sponge host itself, based on the detected hydrocarbon chain lengths. This work provides a basis for the challenging quest to decipher intricate EL biosynthesis in marine sponges and their associated microbes.

Background: Cognitive function is crucial for healthy aging, and its impairment reduces quality of life and increases healthcare and societal burden. Social vulnerability, shaped by factors like income, education, and access to healthcare, has been associated with cognitive health, but reliance on community-level assessments may limit understanding of risk at the individual level. Objectives, Design, Setting, Participants: We examined the cross-sectional association between a proposed individual-level Social Vulnerability Index (iSVI) and cognitive function among 5,989 participants aged [&ge;]60 years in the US National Health and Nutrition Examination Survey (NHANES) 1999-2002 and 2011-2014 cycles. Measurements: Cognitive performance was measured using the Digit Symbol Substitution Test (DSST). iSVI was constructed by summing six risk indicators (income, education, health insurance, employment, housing tenure, and food security). Health insurance and employment were scored on a three-level scale (0/0.5/1); other indicators were binary (0/1). Survey-weighted linear regression estimated associations between iSVI and DSST scores, adjusting for age, sex, race and Hispanic origin, and survey cycle. Estimates were benchmarked against adjusted associations between age and DSST. Results: Higher iSVI was associated with poorer cognition, with each one-unit increase corresponding to a 5.30-point lower DSST score (95% CI: -5.71, -4.89). This difference was comparable to nearly 5 years of age-related difference in DSST performance, as each additional year of age was associated with a 1.08-point lower DSST score (95% CI: -1.14, -1.03). Conclusions: Increased iSVI was associated with lower cognitive function in older adults, highlighting individual-level social vulnerability as a key intervention opportunity to prevent cognitive impairment.

Multimodal imaging approaches that combine structural and functional neuroimaging provide a robust framework for examining neuroplastic adaptations that may not be captured by any single modality. The present study investigated the effects of a four-week expiratory muscle strength training (EMST) program on structural and resting-state functional connectivity in healthy young adults. Five healthy young adult males (aged 19-35 years) completed a standard four-week EMST protocol and underwent pre- and post-training imaging assessments. Structural neuroimaging included T1-weighted and diffusion-weighted MRI, which were analyzed using voxel-based morphometry, surface-based morphometry, and white-matter structural connectivity. Functional neuroimaging consisted of resting-state fMRI to assess training-related changes in functional architecture, network connectivity, and global network measures. Structural MRI analyses revealed no significant changes in gray or white matter volume, cortical morphology, or white-matter structural connectivity following EMST (all FWE- or FDR-corrected p > .05). In contrast, resting-state fMRI demonstrated a significant increase in whole-brain functional connectivity (FDR-corrected p = .036), accompanied by greater network integration, reflected in increased local efficiency and transitivity and reduced modularity. Network-level analyses showed enhanced within- and between-network connectivity in sensorimotor and cognitive circuits. Our findings demonstrate robust functional reorganization following EMST, despite the absence of detectable macrostructural or large-scale white-matter connectivity changes, at least within the timescale and sample characteristics of the current study. These results reflect early-stage neuroplasticity, both globally and within the networks underlying speech and swallowing control and suggest that functional reorganization occurs early in training and likely precedes longer-term structural modifications in these networks.

Naturalistic social interaction provides an important context for examining how cognitive engagement is reflected in brain activity, yet electroencephalographic evidence from older adult caregiver interaction remains limited. This study examined alpha band EEG dynamics during museum-based storytelling interaction in older adult caregiver dyads. Thirty two dyads, comprising 32 older adults and 32 caregivers, completed cognitive and psychological screening and underwent EEG recording during eyes-closed resting, eyes open resting, storytelling, and listening conditions. Relative alpha power was analyzed using a predefined 10-electrode sensor-level set covering frontal, frontotemporal, temporal, central, and parietal midline regions. Task-related alpha modulation was examined relative to eyes-open resting. Associations between cognitive performance and Cz alpha power were tested using MoCA scores, and dyad level alpha band inter-brain similarity was examined using spatial alpha-power patterns with within site shuffled dyad surrogate comparisons. Alpha power was higher during eyes closed resting and lower during storytelling and listening relative to eyes-open resting, indicating robust task-related modulation of alpha activity during naturalistic narrative interaction. Associations between MoCA scores and Cz alpha power were weak, condition specific, and did not survive false discovery rate correction. During storytelling, dyad level alpha band inter brain similarity was modestly higher than within site shuffled dyad estimates, but this effect did not remain significant after correction across conditions. These findings suggest that alpha band EEG activity is sensitive to naturalistic storytelling and listening in older adult caregiver dyads. However, cognitive associations and dyad level inter brain similarity were modest and should be interpreted cautiously. The study demonstrates the feasibility of applying EEG to real world social cognitive interaction while highlighting the need for larger samples, behavioral coding, and time resolved dyadic EEG methods to clarify mechanisms of interpersonal neural coordination.