International Journal of Psychophysiology

BackgroundAutonomous sensory meridian response (ASMR) and music-induced frisson are sensory-affective phenomena characterized by tingling, chills, and pronounced emotional responses. Previous research has mainly focused on physiological changes during these experiences, whereas much less is known about whether baseline physiological state is associated with subsequent susceptibility. ObjectiveTo examine whether baseline autonomic flexibility, indexed primarily by heart rate variability (HRV), is associated with later ASMR/frisson responsiveness. Resting EEG measures were included as secondary exploratory markers. MethodsFifteen participants were recruited by convenience sampling; after artifact-based exclusion, 10 participants were included in the analyses. A 5-minute resting baseline EEG and ECG was recorded prior to stimulus presentation. Participants were then exposed to auditory and audiovisual ASMR stimuli, classical music excerpts, and a control stimulus, and reported whether they had experienced ASMR-typical sensations or frisson. Main analyses examined associations between baseline physiological parameters and a combined response-positive outcome. Exploratory analyses included participant-level correlations, comparisons between susceptible and non-susceptible participants, and stimulus-specific effect sizes. ResultsHRV-related measures showed the clearest and most consistent pattern of association with responsiveness. Higher baseline total HRV power was associated with a greater number of response-positive stimuli (r = 0.756, p = 0.011), with similar positive associations for high-frequency HRV (HF; r = 0.672, p = 0.033) and baseline heart rate slope (r = 0.751, p = 0.012). Stimulus-specific analyses likewise showed the most consistent positive baseline effects for total HRV power, with HF and heart rate slope pointing in the same direction. Frontal alpha asymmetry (FAA) was negatively associated with responsiveness ({rho} = -0.862, p = 0.001), but EEG findings overall were less consistent than the HRV-related pattern and are best interpreted as secondary exploratory observations. ConclusionsIn this exploratory pilot sample, baseline HRV, particularly total HRV power, showed the most coherent physiological association with susceptibility to ASMR and music-induced frisson. The findings are consistent with the possibility that these experiences depend not only on stimulus properties, but also on pre-existing physiological state. Given the small sample and exploratory design, the results should be interpreted as hypothesis-generating and require replication in larger confirmatory studies.

Stressors are commonly used in rats to induce models of anxiety or depression. The effectiveness of these stressors is often evaluated using specific behavioural tests. In a previous meta-analysis of chronic variable stress (CVS) procedures, we predicted that longer and more intensive stress procedures would result in larger effect sizes in behavioural tests. However, we found that the duration or intensity of CVS procedures did not correlate strongly with the magnitude of the effect sizes reported in behaviouraltests. In that study, we were concerned that the large and unexplained diversity in CVS procedure design, both in terms of duration and the types of stressors used, made it challenging to detect the factors that were influencing effect size. In an effort to address this, we explore here the use of a much simpler stress procedure - chronic restraint stress (CRS) - to study the relationship between the duration of CRS procedures and the effect sizes obtained in subsequent behavioural tests. We searched PubMed for articles using CRS procedures with rats, systematically documented the total duration of restraint, and carried out a meta-analysis of the effect sizes obtained in four behavioural tests: the forced swim test (FST), the sucrose preference test (SPT), the elevated plus maze (EPM) and the open field test (OFT). We found that chronic restraint stress increased immobility in the FST, decreased sucrose preference in the SPT, decreased time spent in the open arms of the EPM but had no effect on time spent in the centre of the OFT. However, the effect sizes in all behavioural tests, except the SPT, were not moderated by the duration of the CRS procedure, indicating that longer CRS procedures are associated with larger effect sizes in the SPT but not in the FST or EPM.

Mental fatigue is induced by prolonged engagement in cognitively demanding tasks and impairs endurance performance. The neuropsychophysiological mechanisms underlying this decreased performance remain unclear, with suggestion that mental fatigue may disrupt motor command and consequently muscle activation. We aimed to test this hypothesis in a repeated cross-over design study in which 18 participants completed two experimental sessions involving a time-to-exhaustion cycling test at 80% of peak power output. Each cycling task was preceded by 1h of a prolonged Stroop task (Stroop session) or a neutral control task (Control session). Perception of effort and surface electromyography from ten lower-limb muscles of the right leg were recorded at regular intervals during cycling. Mental fatigue was higher in the Stroop compared to the Control session (p = .002). Endurance cycling time was 111 {+/-} 160 s shorter in the Stroop than in the Control session (p = .009). No significant differences in electromyography parameters were observed between Stroop and Control sessions, for any muscle (p > .05). Perception of effort was higher in the Stroop session from the onset of the cycling task (p = .006), and the rate of increase in perception of effort was significantly higher in the Stroop than Control session (p = .031). Our findings do not support the hypothesis that mental fatigue alters motor control or increases central motor command, as no changes in muscle activation were detected. Conversely, our results reinforce the notion that prolonged cognitive engagement impairs endurance performance primarily through an increased perception of effort. Future research should consider combining surface electromyography with more sensitive neurophysiological techniques to investigate potential subtle changes in motor drive during dynamic, whole-body tasks under mental fatigue. Impact statementOur study confirms that mental fatigue induced by prolonged cognitive exertion impairs cycling endurance performance. By combining measurements of perceptual responses and multi-muscle surface EMG during the endurance task, we observed that the decreased endurance performance is related to an increased perceived effort in the presence of mental fatigue, not related to alterations in motor command.

Exercise is a positive health behaviour associated with improved mood. However, the mechanisms underlying the benefits of exercise on affective health are unclear, particularly with respect to type of exercise and sex. Chronic exercise decreases neuroinflammation, which is linked to improvements in mood and anxiety. However, exercise is also a physiological stressor that can transiently upregulate systemic inflammation, and its effects on neuroinflammation are not well understood. This study examined how acute and chronic exercise affect circulating and brain cytokine levels and anxiety-related behaviour in young healthy male and female mice. In Experiment 1, mice were placed on a treadmill for a two-hour bout of moderate exercise. Two hours after exercise, animals were either tested in the open field or euthanized for measurement of cytokines (IL-1{beta}, TNF, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, IFN-{gamma}, KC/GRO). In Experiment 2, mice underwent an 8-week moderate treadmill exercise paradigm followed by open field testing and tissue collection. Acute exercise decreased time spent in the centre of the open field in males only, suggesting increased anxiety-like behaviour in males. Acute exercise increased IL-6 and decreased TNF in serum, and increased amygdala principal component 1 (loading IL-12p70, IL-10, IFN-{gamma}, and TNF) in both sexes. Chronic exercise increased open field centre entries, increased IL-6 in the prefrontal cortex, decreased TNF in the dorsal hippocampus, and had minimal effects on circulating cytokines in both sexes. These results demonstrate that the effects of exercise on anxiety-related behaviour and cytokine levels depend on recurrence, tissue, and brain region. New & NoteworthyOur work highlights the contrast between anxiogenic and anxiolytic effects of acute versus chronic exercise, respectively, in healthy mice. Acute and chronic exercise differentially affected circulating and brain cytokines, providing insight into physiological adaptations to exercise. Both sexes demonstrated similar cytokine responses to exercise. These similarities are novel with respect to exercise research and noteworthy given sex differences in anxiety with respect to acute exercise.

Reaction time is a measure of the speed of our response to stimuli in the environment. Even for a well-trained task, a subjects reaction time varies. One source of this variability is internal state fluctuations (such as changes in arousal). There are few studies that systematically quantify the extent to which reaction time varies across different timescales and link this to measures of systemic physiology associated with arousal. In much of the literature, it is assumed but not demonstrated that behavioral and systemic measurements associated with arousal will be consistently linked because both estimate a common underlying arousal process. In this work, we examined this assumption by simultaneously measuring reaction time, heart rate, and pupil diameter in rhesus macaque monkeys performing several visual tasks over hours and across hundreds of sessions. We found a portion of the variability in reaction time could be linked to systemic physiological signatures of arousal on fast timescales from second to second and slower timescales from minute to minute. This link between reaction time and systemic physiology was also present for different biomarkers of arousal (heart rate and pupil). However, the strength of this relationship varied depending on the arousal biomarker. Our findings support the conclusion that there are multiple arousal mechanisms that act simultaneously to influence behavior and multiple timescales at which they operate.

ObjectiveFinding indicators of early response to antidepressant treatment in EEG signals recorded from patients suffering from major depressive disorder. MethodsFunctional brain connectivity networks based on weighted imaginary coherence and weighted imaginary mean phase coherence were computed for 176 patients for 6 different EEG frequency bands. Cross-hemispheric connectivity (CH) and lateral asymmetry (LA) were estimated from these networks based on EEG signals recorded before the beginning of treatment (V is1) and one week after the start of the treatment (V is2). Repeated measures ANOVA was used to check for statistically significant changes in connectivity based on these measures at V is2 w.r.t. V is1. Post-hoc analysis was performed with multiple pairwise comparison tests to determine which group means were significantly different. ResultsIt was found that CHV is2 was significantly reduced w.r.t. CHV is1 in the {beta}1 [12.5 - 17.5 Hz] frequency band for the responders to treatment. Also, LAV is2 was significantly increased w.r.t. LAV is1 in the {beta}1 frequency band for the responders. No such significant changes were observed for the non-responders. Brain networks constructed using both weighted imaginary coherence and weighted imaginary mean phase coherence were found to exhibit these results. For the CH connectivity changes, binarized networks and for the LA connectivity changes, weighted networks were found to be more reliable. ConclusionsResponders were found to show a reduction in cross-hemispheric connectivity and an increase in lateral asymmetry, both in the {beta}1 band while no such change was observed for the non-responders. SignificanceDecrease in cross-hemispheric connectivity and increase in lateral asymmetry in the {beta}1 band may represent candidate neurophysiological indicators of early treatment response, but they require independent replication before any clinical application can be considered.

Introduction Experiential acceptance refers to the capacity to be open to internal experiences without attempting to change or avoid them. Although acceptance is a core emotion regulation strategy within mindfulness- and acceptance-based interventions (MABIs) and a protective factor for mental health, its conceptualization and implementation remain unclear and ambiguous. The aim of this study was to clarify and develop a comprehensive model of accepting anxiety. Method Twenty-six participants from a non-clinical sample with prior experience in MABIs took part in semi-structured interviews exploring their experience of accepting anxiety. Data collection and analysis followed the principles of Grounded Theory to generate a data-driven model of the acceptance process. Results We identified a five-stage dynamic model involving distinct processes: (Stage 1) observing through the body with attentional focus on interoceptive experience; (Stage 2) identifying and acknowledging anxiety; (Stage 3) validating and normalizing the experience through validation and self-compassion; (Stage 4) not reacting characterized by decentering and nonreactivity; and (Stage 5) staying with the experience via exposure. We also identified facilitating factors that support engagement in the acceptance process. Conclusion These findings refine the understanding of acceptance as a multidimensional emotion regulation process by highlighting an active dynamic involving multiple mechanisms underlying the acceptance of anxiety. This model provides a framework for developing more targeted clinical interventions and for investigating individual and contextual variability in these subprocesses.

BackgroundContemporary research indicates that psychedelics induce notable neurophysiological changes, some lasting weeks to months after a single dose. However, most evidence derives from acute administration studies and limited post-acute follow-ups. Long-term naturalistic psychedelic users remain critically underexamined, yet may exhibit distinct neurobiological profiles informing our understanding of persistent alterations following repeated exposure. MethodsWe recorded resting-state EEG in 57 long-term psychedelic users (abstinent [≥]30 days) and 49 matched non-users across two independent sites under eyes-open and eyes-closed conditions. We analyzed oscillatory power, signal complexity, and source-localized effective connectivity, focusing on five canonical frequency bands and regions of the Default Mode, Salience, and Central Executive Networks. Analyses included linear mixed-effects modeling for power spectra and complexity results and a rank-based approach combining ordinary least squares regression with randomization inference for effective connectivity. ResultsWe observed predominantly null findings. No significant between-group differences emerged for oscillatory power. Complexity comparison yielded results contrary to our hypothesis: psychedelic users exhibited lower complexity values in the eyes-open condition. Effective connectivity revealed no within- or between-network differences that would survive statistical corrections. Additionally, we report a few small-magnitude effects uncovered by exploratory analyses. Conclusions Long-term naturalistic psychedelic users showed largely non-significant differences in oscillatory power, complexity, and network connectivity compared to non-users -- across several measures commonly reported as altered in acute administration studies. These findings raise the question of whether psychedelics neurophysiological signatures persist during abstinence despite repeated prior use, or whether they reflect homeostatic receptor adaptation, individual variability, or contextual factors. Null, incongruous, or subtle effects contribute to the existing evidence base, yet underscore the need for replication in larger, more ecologically valid populations to advance the emerging field of psychedelic neuroscience.

General anesthetics enable invasive experimentation but can affect cardiovascular and respiratory physiology, biasing preclinical outcomes. We compared five anesthetic regimens in adult male Wistar rats, tribromoethanol (TBE, 250 mg/kg i.p.), chloral hydrate (CH, 400 mg/kg i.p.), ketamine-xylazine (KX, 80/10 mg/kg i.p.), thiopental (TP, 80 mg/kg i.p.), and isoflurane (ISO, 4% induction, 2% maintenance), to investigate integrated cardiorespiratory and biochemical markers. Femoral arterial catheterization allowed continuous blood pressure (BP) and derived heart rate (HR) recordings, while ventilation was assessed through pletysmography at baseline (awake), during induction, and recovery phases of anesthesia. Variability was evaluated in the time and frequency domains, including HR, systolic blood pressure (SBP), and spontaneous baroreflex sensitivity. In an independent cohort of rats, butyrylcholinesterase (BChE), CK-MB, cTnI, and LDH were measured. Baseline BP was unchanged by TBE and TP, whereas all anesthetics affected HR. Minute ventilation and breathing frequency were reduced with all agents, while tidal volume decreased with KX and TBE only. LDH and cTnI were unaffected, BChE was reduced by KX, TBE, and ISO, and CK-MB increased with CH and KX. Variability analysis showed that all anesthetics depressed pulse-interval and SBP variability and shifted spectral power toward higher frequencies, while baroreflex sensitivity and effectiveness were consistently reduced. During recovery, KX and TP restored most variability indices, whereas CH, TBE, and ISO showed persistent suppression. These findings highlight distinct profiles of cardiovascular depression and biomarker responses across anesthetics and underscore the importance of accounting for autonomic variability when selecting different anesthetics in experimental protocols. HighlightsO_LIFive anesthetic regimens were tested in rats. C_LIO_LIAll anesthetics reduced ventilation, and KX and TBE also reduced tidal volume. C_LIO_LICH and KX increased CKMB, while KX, TBE and ISO reduced BChE. C_LIO_LIAll anesthetics reduced blood pressure variability and baroreflex sensitivity. C_LIO_LIVariability recovered with TP and KX, whereas CH, TBE and ISO showed persistent suppression. C_LI

AO_SCPLOWBSTRACTC_SCPLOWDecoding imagined speech from electroencephalography (EEG) recordings is potentially useful for brain-computer interfaces. Previous studies have focused on decoding semantic information from EEG, leaving the decoding of emotion - an important component of human communication - largely unexplored. Here, we report two experiments involving participants tasked with overt (n = 14) or imagined (n = 21) emotional vocalisation in five different categories: anger, happiness, neutral, sadness, and pleasure. Throughout, we recorded 64-channel EEG; we computed time-frequency features and used a logistic-regression classifier to evaluate emotion decoding accuracy. In five participants, we also recorded facial surface electromyography (sEMG) during imagined vocalisation, and studied the contamination of EEG by sEMG. Our results show that emotion can be decoded from single-trial EEG recordings of both overt (78.1%, chance = 20%) and imagined vocalisation (36.4%). The high-gamma band (50 to 100 Hz) and lateral EEG channels (T7, T8, and proximal) were important for decoding. sEMG analysis indicated that involuntary facial muscle activity contributed to these spectral and spatial patterns during imagined vocalisation, especially during happy vocalisations. We conclude that involuntary facial muscle activity is associated with certain emotion categories (i.e., happiness), and drives above-chance decoding of emotion from single-trial EEG recordings of imagined vocalisation.

Human-dog interaction is widely used to alleviate stress, yet the accompanying cortical and autonomic dynamics during acute stress and recovery remain incompletely characterized. In this study, 70 adult dog owners completed a standardized stress protocol while prefrontal cortex activity was continuously monitored with functional near-infrared spectroscopy (fNIRS), alongside subjective stress and salivary cortisol measures. Participants then underwent a recovery phase involving interaction with a companion dog, manipulating contact type (direct in person vs. indirect video conferencing), and familiarity (own vs. unfamiliar dog). Stress responses were quantified through heart rate (HR), heart rate variability (HRV), low- and high-frequency spectral power (LF, HF, and LF/HF), and prefrontal functional connectivity (FC) based on maximum cross-correlation coefficients between fNIRS channels. As expected, HR, HRV-derived indices, and FC increased from baseline to the stress phase, confirming robust engagement of autonomic and prefrontal networks. During the recovery phase, all dog interaction conditions demonstrated reductions in HR, LF/HF ratio, and FC toward or below baseline, consistent with physiological and neural stress recovery; direct interaction was associated with particularly pronounced parasympathetic enhancement and a drop in FC that fell significantly below baseline in some cases. Across groups, HRV, LF/HF, and FC were the most consistent predictors of subjective stress ratings, whereas associations with cortisol were limited. These findings suggest that human-dog interaction promotes coordinated autonomic and prefrontal recovery from acute stress, and that fNIRS-derived metrics might provide a marker of stress modulation that can distinguish high-cognitive load and low cognitive demand states beyond traditional stress indices.

BackgroundGrowing evidence suggests that sleep plays an important role in PTSD outcomes, potentially due to its influence on emotional memory consolidation, though these mechanisms remain unknown. This study sought to test the hypotheses that sleep neurophysiology, PTSD status, and sex moderates the degree to which the late positive potential (LPP) mediates memory accuracy for affective visual stimuli. MethodsN = 39 participants (18 female) viewed 75 negative and 75 neutral IAPS images while EEG was recorded. After viewing the images, participants took a two-hour long nap which was followed by a memory assessment. Memory accuracy was measured using d = Z(hit rate) - Z(false alarm rate), where hit rate refers to the proportion of images seen during the memory assessment that are correctly identified as being previously seen, false alarm rate refers to the proportion of images seen during the memory assessment that are incorrectly identified as being previously seen, and Z() is the inverse cumulative distribution function of the standard normal distribution function. ResultsThe early (300 - 1000 ms) and late (1000 - 1500 ms) LPP mediated enhanced discrimination accuracy for emotional compared to neural stimuli (d) (ps < 0.001). The association between the late LPP and d was moderated by sleep such that the association was stronger when participants spent proportionately more time in N3 and REM (p = 0.02). The differences in reactivity between emotional and neutral images for both the early and late LPP were attenuated in PTSD+ individuals vs. controls (ps < 0.001). Despite mediation results showing greater d for emotional compared to neutral stimuli, women showed overall worse memory accuracy for negative compared to neutral stimuli (p < 0.001) whereas men showed no difference (p = 0.64). ConclusionsN3 and REM sleep play a critical role for memory of stimuli that produce large and sustained neural responses. PTSD is marked by a diminished ability to distinguish between negative and neutral information. More research is critical to understand sex effects on emotional memory.

Interpersonal neural synchrony (INS) in mother-child dyads is often interpreted as a neural marker of relational quality and sensitive caregiving, yet findings on its predictors remain heterogeneous. One possible source of this variability is the diversity of interactional paradigms used in hyperscanning research. This study examined how maternal personality, child temperament, and affective states relate to INS across interaction contexts varying in social interactivity. Thirty-three mother-child dyads (n = 20 female children) participated in a functional near-infrared spectroscopy hyperscanning experiment involving passive video co-exposure, a structured cooperative task, and free interaction. Fronto-temporal activity was recorded simultaneously, and INS was computed using wavelet transform coherence. Above-chance levels of INS emerged in inter-brain region combinations primarily involving the mothers left inferior frontal gyrus (IFG) and the childs right IFG (adjusted ps < 0.030, Cohens d range = 0.14-0.31). Maternal neuroticism was the only significant predictor of INS, with higher levels associated with increased synchrony during passive video co-exposure (adjusted p = 0.012) and free interaction (adjusted p = 0.021), but not during the structured game. These findings indicate that maternal dispositional traits shape INS in a context-dependent manner. Notably, the positive association between neuroticism and INS suggests that heightened neural synchrony may reflect over-attunement in more anxious caregivers, rather than optimal coordination. Excessive synchrony may therefore index tightly coupled, over-monitoring interaction dynamics, consistent with models of affiliative vigilance in anxious parenting. Overall, INS may follow a non-linear pattern in which moderate levels are most adaptive, highlighting its flexible, dynamic, and context-sensitive nature.

Previous research has demonstrated that children exhibit superior - as compared to adults - consolidation of newly acquired motor sequences across post-learning periods of wakefulness. Given that consolidation is thought to be supported by the reactivation of learning-related patterns of brain activity during the rest periods following active task practice, we hypothesized that the childhood advantage in offline consolidation may be linked to greater reactivation during post-learning wakefulness. Twenty-two children (7-11 years) and 23 adults (18-30 years) completed two sessions of a motor sequence learning task, separated by a 5-hour wake interval. Multivoxel analyses of task-related and resting-state functional magnetic resonance imaging data were employed to assess the persistence of learning-related patterns of neural activity into post-task rest epochs, reflective of reactivation processes. Behavioral results demonstrated the previously reported childhood advantage in offline consolidation over a post-learning wake interval. Imaging results revealed that children exhibited greater persistence of task-related hippocampal - but not putaminal - activity into post-learning rest as compared to adults. These findings suggest that the childhood advantage in awake motor memory consolidation may be supported, at least partially, by enhanced reactivation of task-dependent hippocampal activity patterns during offline epochs.

Both episodic memory and word retrieval have been linked to power decreases in the alpha and beta oscillatory bands, but these patterns have rarely been related to each other, partly due to a lack of methodological approaches available. In this explorative study, we investigate the similarities and dissimilarities in the oscillatory fingerprints of the retrieval of words and episodes by directly comparing the activity patterns across time, frequency, and space. We acquired electroencephalography (EEG) data of participants performing a language and an episodic memory task based on the same stimulus material. With a newly developed approach, we directly compared the source-reconstructed oscillatory activity using mutual information and a feature-impact analysis. While left temporal and frontal regions showed dissimilarities between the tasks, right-hemispheric parietal regions exhibited similarities. We speculate that this could indicate a homologous function of these regions, potentially sharing less-specific representations between the tasks. We further uncovered a dissociation of the alpha and beta bands regarding the similarity across tasks. While the beta band was dissimilar between word and episodic memory retrieval, the alpha band seemed to contribute to the similarity we observed in right parietal regions. Whether this points to a task-unspecific function of the alpha band or a functional role in the retrieval process of the presumed representations, remains to be determined. In summary, we present an approach to study similarity across tasks using the temporal, spectral, and spatial dimensions of EEG data, and present results of exploring the shared oscillatory fingerprints between episodic memory and word retrieval.

Nicotine use disorder shows heterogeneity in treatment response, potentially reflecting differences in underlying neural circuitry, particularly in the presence of depression. We examined real-time neural dynamics during nicotine inhalation in two chronic users - one with depression and one without - using simultaneous hippocampal recordings from responsive neurostimulation (RNS) electrodes and scalp EEG. Oscillatory activity and hippocampal-cortical connectivity were analyzed in relation to mood and craving. Oscillatory activity tracked mood in the non-depressed individual but was attenuated or reversed in the depressed individual, suggesting reduced reward-related neural responsiveness. In contrast, both participants showed reduced alpha hippocampal-cortical connectivity following nicotine use, suggesting a shift from reward-seeking to reward and relief processing. These findings support a network-based framework of nicotine-driven neural dynamics and provide preliminary evidence that depressive status may modulate these processes. Although limited to two cases, this work highlights the potential for identifying neurophysiological subtypes of nicotine users and informs future efforts toward personalized treatment approaches.

BackgroundDepression is associated with social dysfunction, but the mechanisms linking affective symptoms to disrupted close relationships remain poorly understood. One possibility is that depression alters how people experience rewards shared with close others and how they interpret partners actions. It remains unclear whether neural sensitivity to shared reward predicts social valuation during more complex interactions such as reciprocated trust. MethodsIn this preregistered fMRI study, participants completed a reward-sharing task and a Trust Game with a close friend, a stranger, and a computer. We measured striatal shared reward sensitivity (SRS; friend > computer) and tested whether it related to subsequent investment behavior and brain responses to trust reciprocation. Depressive symptoms and perceived closeness were assessed via self-report. ResultsIn a final sample of n = 123, participants reporting more depressive symptoms invested more in their friend than in the computer. Striatal SRS predicted temporoparietal junction responses to reciprocated trust, but this association depended jointly on social closeness and depression -- with depression reversing the expected pattern among individuals reporting closer relationships. Striatal SRS was also inversely associated with connectivity between the default mode network and cerebellum during reciprocity. ConclusionsThese findings suggest that closeness calibrates the striatal SRS link to regional activity and network-level responses during social exchange, while depression alters how striatal SRS relates to regional activity, potentially disrupting how individuals interpret and respond to close others.

Background Diagnosis and treatment monitoring of attention-deficit/hyperactivity disorder (ADHD) largely rely on subjective assessments, highlighting the need for objective markers. Voice features and speech embeddings represent promising candidates for such markers, as they may capture alterations in speech production relevant to ADHD. However, it remains unclear which speech features are most informative for distinguishing ADHD and monitoring treatment effects, and which speech tasks most reliably elicit such differences. Methods Twenty-seven children with ADHD and 27 age-matched neurotypical controls completed six speech tasks across two study visits. Children with ADHD were unmedicated at baseline (first visit) and were assessed under prescribed methylphenidate treatment at follow-up, whereas controls underwent repeated assessment without intervention. Established acoustic voice features (eGeMAPS) and high-dimensional speech embeddings (WavLm, Whisper) were extracted and analysed using linear mixed models to examine baseline group differences and group-by-time interaction effects reflecting medication-associated change patterns. Results At baseline, children with ADHD differed significantly from controls in frequency, spectral, and temporal voice features, characterized by lower and more variable pitch, altered spectral properties, and reduced rhythmic stability. Group-by-time interaction effects indicated medication-associated modulation in the ADHD group, including reduced loudness variability and increased precision of vowel articulation at follow-up, changes not observed in controls. Speech embeddings revealed additional baseline and interaction effects beyond established acoustic features. Free speech tasks, particularly picture description, yielded the most robust and consistent effects. Conclusion Children with ADHD differed from neurotypical controls in vocal features at baseline and showed distinct longitudinal change patterns consistent with medication-related change. These findings support further investigation of speech-based measures as candidate digital phenotypes and potential digital biomarkers in ADHD, with picture description emerging as a particularly promising task for future clinical assessment protocols.

Background. Adolescence and young adulthood represent critical developmental stages during which mental disorders often emerge, with the potential to impede perceived quality of life. Spirituality (i.e., the search for the sacred) and self-regulation (i.e., intrinsic processes regulating emotions, thoughts, and behaviors) are recognized as protective factors for mental health. However, their dynamic interplay remains largely unexplored, particularly in real-life and in real-time among youths. This study, developed with the help of young partners, addresses this gap by investigating the longitudinal associations between spirituality, self-regulation, and mental health using an ecological momentary assessment (EMA) approach. Methods and analysis. We plan to recruit 120 adolescents and young adults (aged 16 to 20, expected attrition rate of 20%) from the community to complete a qualitative semi-structured interview assessing their beliefs, spiritual or religious activities, role models, and meaning in life. In addition, participants will take part in a multi-wave intensive longitudinal study. Trait-level assessments will be conducted at two time points, three months apart, to capture between-person differences. Additionally, to assess within-person dynamics, participants will complete EMA surveys four times daily over 10 consecutive days in two waves, also three months apart. Measures will include facets of spirituality (e.g., beliefs, meaning, collective consciousness), self-regulation (e.g., self-control, emotional regulation, impulsivity), as well as mental health indicators (emotional and behavioral symptoms) and quality of life. Qualitative data will be analyzed through a thematic analysis method, whereas quantitative associations will be assessed using Linear Mixed Models (LMM) and network analyses. Ethics and dissemination. Ethical approval has been obtained, and data collection begun in May 2025. Findings will be disseminated through open access peer-reviewed journals, conferences on adolescent mental health, and shared with practitioners, educators, and youth organizations. Results will also be made accessible to the general public. This study aims to inform personalized preventive and therapeutic interventions by elucidating real-time mechanisms linking spirituality, self-regulation, and mental health in youths.

Pregnant women are particularly susceptible to adverse outcomes from environmental heat, yet the physiological effects of acute heat exposure during pregnancy remain poorly understood. Some physiological changes are monitored in humans; however, investigation of underlying molecular mechanisms requires invasive methods that can only be ethically applied in mammalian models. Moreover, research with animal models has largely focused on early and lethal teratogenic effects of heat exposure and lacks longitudinal physiological monitoring, detailed parameterisation of heating regimes and in-depth investigation of underlying mechanisms. Here we used a mouse model to investigate the impact of a controlled acute heat exposure at mid-gestation (E12{middle dot}5), slowly elevating core body temperature (CBT) over 210mins to raise CBT by [~]1{degrees}C. Using high-frequency ultrasound and morphological analyses, we observed delayed alterations in placental and foetal cerebral blood flow indicative of a brain-sparing response, alongside reduced placental labyrinth zone size. Additionally, maternal cardiac function was impaired, accompanied by cardiac and renal fibrosis and elevated circulating soluble Flt-1 levels, an anti-angiogenic biomarker of gestational hypertension. These findings demonstrate that brief heat stress at mid-gestation can induce lasting effects on placental function and maternal cardiovascular health in a mammalian model, highlighting potential risks for pregnancy outcomes under increasing global temperatures. Together this data suggests that an acute exposure to heat elevating core body temperature by 1{middle dot}2{degrees}C can induce a long-term impact on both placenta and maternal health in a mouse model. It will be important to understand the molecular changes which underpin the pathophysiology and whether this is translated to humans.