Psychophysiology

Interpersonal physiological synchrony (IPS) between interaction partners has been studied as a marker of social connectedness and coordination. However, little is known about how such interpersonal synchrony relates to the intrapersonal coordination of individuals' own autonomic systems during team interaction. The present study examined whether IPS and intrapersonal physiological synchrony (IAPS), defined as the within-person coordination of heart rate (HR), respiration, and electrodermal activity (EDA), function as competing or complementary regulatory processes. It also examined whether IAPS is state- or trait-like and whether teams high or low in both IPS and IAPS had better outcomes. Fifty five newly formed triads (N = 165; Mage = 23.87, 77% female) participated in a laboratory interaction including passive shared experiences and active collaborative tasks while continuous physiological activity was recorded. Synchrony within individuals and between team members was quantified using multidimensional recurrence quantification analysis. Across interaction segments, IAPS was positively associated with IPS in both HR and EDA, with stronger and more consistent associations during active teamwork versus during passive social contexts. These findings contradict a trade-off hypothesis and instead support a synergistic relationship between IAPS and IPS. IAPS exhibited state-like dynamics and sensitivity to features of the context, i.e., consistency within similar interaction contexts and higher in passive versus active social segments. Further, IAPS had limited associations with individual difference measures. Exploratory analyses indicated that teams characterized by both high IAPS and high IPS demonstrated more favorable outcomes, reflected in either higher objective task performance or greater perceived team efficacy depending on physiological modality. Together, these results suggest that effective team coordination is supported not only by IPS but also by the capacity to maintain coherent internal autonomic organization. They further highlight IAPS as a dynamic component of social functioning that merits exploration alongside interpersonal processes.

Motor effort has been shown to bias perceptual decisions toward less effortful choices, but it remains unknown whether this bias already takes effect during the early stages of decision formation through preparatory attentional allocation or sensory processing, or during later-stage evidence accumulation preceding response execution. This study investigated when motor effort becomes integrated into decision formation by focusing on the temporal evolution of neural processing during perceptual decision-making. While 64-channel EEG was recorded, twenty-four healthy adults performed an orientation discrimination task in which two Gabor patches appeared simultaneously in the left and right visual hemifield and decisions were reported using two pressure-sensitive response buttons requiring different levels of force. We found that motor effort modulated EEG activity at both the preparatory and later decision stages: pre-stimulus alpha power was reduced over the occipito-parietal cortex contralateral to the low-effort option, and mean centro-parietal positivity (CPP) amplitude preceding response execution was greater over centro-parietal cortex for low-effort choices, while leaving early sensory representations intact as indicated by no differences in P1 or N1 amplitude following stimulus onset. Trial-by-trial CPP amplitude preceding response execution increased with the likelihood of selecting the low-effort option, whereas the pre-stimulus alpha modulation was not associated with behavioral decision bias. These findings suggest that motor effort biases perceptual decisions primarily during later-stage evidence accumulation, thereby providing insight into the neural basis of embodied perceptual decision making.

Anticipatory neurophysiological activity before unpredictable emotional events has been reported for decades, but the effects are small, difficult to replicate, and obtained almost exclusively in stripped-down laboratory paradigms. Whether they reflect genuine predictive processes or methodological artifacts remains debated; one rarely tested possibility is that such settings mute it. We examined anticipation in an immersive virtual reality (VR) driving simulation whose collision outcomes were assigned by a quantum random number generator, while EEG, photoplethysmography (PPG), EMG, EOG and inertial (IMU) signals were recorded from a single wireless dry-electrode headset built into the VR display. Sixteen participants passively observed 120 driving sequences ending in a collision or no collision. Length-matched pre- and post-stimulus windows were analysed identically with mass-univariate hierarchical general linear models under permutation cluster correction, plus machine-learning classification across held-out participants. Two post-stimulus clusters differentiated the conditions, the largest peaking at 451.6 ms (d = -1.35), with broadband power modulation robust to baseline modelling, decoded from held-out participants with up to 93.8% accuracy. No time-domain effect or decodable information preceded stimulus onset, but a broadband spectral difference did, surviving preregistered controls for expectation bias (run length), time-on-task build-up and ocular or facial-muscle artifact: directionally consistent in 13 of 15 participants, with pre- and post-stimulus power coupled in all 16. Heart rate differentiated the conditions neither alone nor when added to the classifier. The study was preregistered; the BIDS-format data, analysis code and an open-source EEGLAB plugin are publicly available.

Objective: Women with premenstrual syndrome (PMS) experience affective lability, irritability, depressed mood, and anxiety during the late luteal phase of the menstrual cycle. Stress reactivity may contribute to the development of these symptoms, yet neural correlates remain unexplored. We examined neural, behavioral and endocrine stress responses across menstrual cycle phases in women with and without PMS. Methods: 26 women with PMS and 24 women without PMS participated in two fMRI sessions, during the mid-follicular (days 5 to 11) and late-luteal phases (days -7 to -1). Participants completed the Montreal Imaging Stress Task (MIST). Subjective stress ratings and salivary cortisol were collected at six time points before and after stress induction. Stress-related brain activation was assessed using whole-brain and region-of-interest analyses. Results: Subjective stress ratings increased as expected from before to after the MIST, with no group or phase differences. Salivary cortisol was significantly higher during the mid-follicular phase, with no group effect or significant pre-post MIST difference. While the stress task elicited activation patterns in stress-related regions, whole-brain analysis revealed no significant effects of group (PMS vs. no PMS) or menstrual cycle phase (follicular vs. luteal) on the neural stress response. Considering premenstrual symptom severity as a predictor revealed significant group-by-symptom severity interactions in the right inferior frontal gyrus and the right superior temporal gyrus. Conclusion: Using a within-subject repeated-measures design, we found neural responses to psychosocial stress to be stable across menstrual cycle phases. Individual differences in symptom severity may nevertheless be associated with differences in stress-related brain activation.

Self-control is the capacity to resist self-defeating behavior in favor of long-term goals. Such behavioral control is fundamental to adaptive human behavior, yet its neural mechanism remains unclear. A key limitation of prior research is that tasks often conflate self-control with cost-benefit evaluation, making it difficult to isolate self-control encoding. We introduced a novel dynamometer-based task where participants chose between high-effort, larger-later (L) and low-effort, smaller-sooner (S) rewards. In some trials, referred to as temptation trials, participants could maintain their initial commitment (LL/SS) or switch (LS/SL). Twenty-six participants performed the task during a 32-channel EEG recording. Behavioral results showed a significant shift from L to S options in temptation trials, suggesting frequent yielding to temptation. EEG activity covaried with switching behavior. The late positive potential (LPP) differentiated stay (LL) from switch (LS) trials before initial choice, localizing to the posterior cingulate visual area and left somatosensory regions. Enhanced LPP in LS trials is thought to reflect heightened motivational conflict and attentional engagement with alternatives. Time-resolved multivariate decoding reliably discriminated LL from LS outcomes, peaking 304-348ms post-option presentation. This was driven by distributed frontal and centroparietal networks, demonstrating that a neural bias toward yielding is established well before the initial choice at the network level. The EEG activity preceding switching predicted the final choice, reflecting reward anticipation rather than self-control signals. Together, these findings suggest that proactive neural states during deliberation, established before the choice, shape self-control success and failure.

We investigated how auditory and visual presentation of small numerical magnitudes and non- numerical magnitudes are passively processed at the neural level. Earlier research suggests automatic processing of quantities occurs rapidly in the brain. However, there are no studies on passive, pre-attentive change detection of magnitudes utilizing mismatch negativity (MMN) across sensory modalities in same participants, important to understand amodal processing of magnitudes. We recorded EEG in passive auditory and visual multi-feature oddball and control paradigms from the same adult individuals (N=104/105, respectively). In the auditory paradigm, the standard stimulus was a 2-part sound, while the deviant stimuli varied in frequency, intensity, gap length, and number of sounds (1-part and 3-part stimuli). In the visual paradigm, the standard stimulus was a dot array containing two medium-sized dots, while the deviant stimuli varied in numerosity (1 or 3 dots) and dot size (small or large). The results for the auditory paradigm showed significant MMN across all features, including comparisons with deviant-alone control stimuli, except for the 2-part vs. 1-part contrast. The results for the visual paradigm suggested differences in processing across all features apart from large and medium-size stimuli. These results replicate earlier MMN findings that the brain distinguishes pre-attentively changes in sound frequency, amplitude and gap. Auditorily presented small numerical magnitudes also showed pre-attentive processing but less robustly to the contrast 2 vs. 1. Visual pre-attentive processing of small numerical magnitudes was also observed. Together these findings could be interpreted to support the existence of abstract, pre- attentive processing of numerical magnitudes. Highlights* Auditory and visual processing of numerical and non-numerical magnitudes was examined with EEG * Auditory non-numerical magnitudes and medium vs. small dots replicated earlier MMN studies * aMMN and vMMN showed pre-attentive processing of changes in small numerosities 2 vs. 3 and 2 vs. 1 * 2 vs. 1 tone processing was less robust than 2 vs. 3 or the processing of the visual contrasts * The brain processes changes in small non-symbolic magnitudes pre-attentively

Significance: Wearable optical sensors could make continuous cerebral hemodynamic monitoring practical in daily life. Because any surface head sensor also samples extracerebral tissue, demonstrating cerebral relevance requires a reference that separates deep from superficial hemodynamics. Aim: We evaluated whether the Temple Brain Flow Index (Temple-BF), derived from a temple-worn photoplethysmographic wearable, covaried more strongly with the deeper (brain-assigned) than the superficial (scalp-assigned) hemodynamics recovered from time-domain near-infrared spectroscopy (TD-NIRS) during controlled postural challenges. Approach: Sixty sessions from 44 healthy young adult men were analyzed across three physiological challenges: 30{degrees} head-down tilt, stand-to-squat, and stand-to-supine transitions. Optical density and mean time of flight from a three-module TD-NIRS system were inverted with a Monte Carlo-derived two-layer model to obtain scalp- and brain-layer hemoglobin time series. Temple-BF was compared with these model-derived signals using lag-adjusted and zero-lag correlations, paired brain-versus-scalp comparisons, heart rate and short-separation-HbO adjusted partial correlations. Results: Median lag-adjusted correlations between Temple-BF and brain-layer {Delta}HbO traces were 0.912, 0.843, and 0.839 for head-down tilt, stand-to-squat, and stand-to-supine transitions, respectively; corresponding scalp-layer medians were 0.494, 0.700, and 0.767. Paired brain-minus-scalp differences were significant for head-down tilt (median 0.333, p < 0.001) and stand-to-squat (0.110, p < 0.001) but not for stand-to-supine (0.036, p = 0.082) transitions. Zero-lag brain-layer medians were 0.826, 0.701, and 0.796, and the association persisted after adjustment for heart rate (partial r = 0.832, 0.850, 0.654) and for short-separation superficial HbO (0.649, 0.570, 0.438). Transition-window correlations had medians of 0.878, 0.861, and 0.876, with directionally concordant transition responses in 59 of 60 sessions. Conclusions: Temple-BF tracked model-derived brain-layer TD-NIRS {Delta}HbO across all three postural challenges, with larger median correlations against the brain-layer than the scalp compartment in all three protocols, and transition responses in the same direction for almost all sessions. These results support Temple-BF as a relative marker of cerebral hemodynamic change during postural perturbations. Establishing cerebral specificity at the temple, and excluding residual systemic and superficial contributions, will require flow-sensitive references and fuller systemic monitoring.

Flow is a subjective state where tasks feel effortless and rewarding. It has been linked to distinct neural signatures, yet dynamics of these signals remain poorly understood. Here, we investigated spectral dynamics of brain activity in flow. We recorded electroencephalogram (EEG) data at positions AF7, AF8, TP9, and TP10 using a lightweight wearable device worn by ten adult participants while they completed a go-signal task and two stop-signal tasks. Task difficulty was continuously adjusted to induce either a sense of flow or frustration. Time-resolved spectral power and interregional coherence were extracted with continuous wavelet and wavelet coherence transforms; subjective flow was assessed after each block with the short-form Flow-State Scale. Subjective ratings confirmed that the flow and frustration conditions diverged in perception of flow. In the flow block, errors on stop trials coincided with pre-stimulus reductions in right temporoparietal gamma power and frontal beta and gamma power, alongside diminished frontotemporal gamma coherence. Comparison of flow and frustration revealed higher temporal beta power during frustration, consistent with greater cognitive load. Flow may involve finely balanced beta and gamma dynamics, and brief collapses of these rhythms may predict task errors. Spectral dynamics are actionable features for closed-loop engagement monitoring applications.

Neuromarketing mainly seeks to enhance the prediction of marketing stimuli success, such as commercials and movie trailers, by integrating neurophysiological measures with traditional behavioral measures. In the current study, the authors tested whether neural activity could predict consumer valuation and how preferences change after watching commercials, both immediately and over time. Participants (n=161) watched images of products followed by commercials advertising those products while their neural activity was recorded using electroencephalograph (EEG). They watched the product images again a week later without EEG recordings. Immediately after each stimulus exposure, participants stated their willingness to pay (WTP) for the product and how much they liked the commercial. Standard EEG measures showed weak and inconsistent relationships with behavior and yielded near-chance predictions. In contrast, deep learning models applied to the raw neural data achieved substantially higher predictive accuracy, successfully predicting both immediate and delayed WTP and ad liking. Importantly, the authors were able to successfully predict preferences for new participants and/or new products the models were not trained on. However, accuracy declined as generalization demands increased. Moreover, prediction performance declined as value differences narrow. Together, these findings show that neural responses carry reliable and temporally persistent information about consumer valuation and its evolution over time.

Rhythmic visual stimulation offers a non-invasive means of modulating oscillatory brain activity, but conventional flicker may induce considerable visual discomfort. We developed an individualized Gabor flicker stimulation designed to balance neural entrainment and tolerability. In Experiment 1, thirty-four participants passively viewed Plain and Gabor flickers presented at their individual alpha frequency (IAF), IAF - 2 Hz, or IAF + 2 Hz, and at threshold-adjusted or full intensity. Steady-state visual evoked potential signal-to-noise ratio (SNR) was highest at IAF and increased with intensity. Plain and Gabor flickers produced comparable overall SNR, but Gabor flicker was rated as substantially more comfortable and less mentally fatiguing, with stimulation at IAF providing the most favorable balance between neural entrainment and tolerability. In Experiment 2, the optimized stimulation parameters were applied during a retro-cue working memory task using individualized theta and alpha frequency flickers. Stimulation increased SNR and inter-trial phase coherence relative to a non rhythmic Natural condition. No behavioral benefit was observed in the full sample. However, an exploratory subgroup analysis indicated higher accuracy with theta stimulation of cued representations and alpha stimulation of uncued representations than in the Natural condition among participants who showed limited baseline retro-cue benefits. These findings show that individualized Gabor flicker can provide robust and well-tolerated neural entrainment during passive viewing and working memory retention, although its behavioral effects may vary across individuals according to their cognitive performance.

Purpose: To compare continuous wavelet transform (CWT) and short-time Fourier transform (STFT) analyses of the oscillatory potentials (OPs) of the dark-adapted full-field electroretinogram (FFERG). Methods: FFERG recordings from Royal College of Surgeons (RCS) and healthy Brown Norway (BN) rats, wild-type and Atoh7 enhancer-knockout (KO) mice, and patients with diabetic retinopathy and healthy controls were analyzed with STFT and with CWT employing the real Morlet wavelet, after 60 Hz high-pass and sharp 60 Hz notch filtering. Time- and frequency-localized OP features were quantified and the methods compared on detection of transient OP signals. Both were additionally validated using synthetic OP-like bursts of known frequency embedded in each cohort's recorded noise. Results: CWT revealed distinct time-frequency patterns and disease-specific OP alterations across all rat, mouse, and human cohorts, with improved temporal localization and frequency resolution, whereas STFT merged transient features and was more susceptible to noise. CWT-derived dominant-frequency differences reached significance in all three models; the corresponding STFT difference reached significance only in rats (separate tests; methods not directly compared). In synthetic bursts, both methods recovered injected frequencies to within 1-2.5 Hz, but only CWT resolved two bursts separated by 15 ms. Conclusions: CWT employing the real Morlet wavelet provides a robust, physiologically relevant evaluation of OPs, with improved temporal localization and reduced spectral dispersion relative to STFT in clinical and experimental settings. Translational Relevance: CWT analysis may improve the characterization of inner retinal dysfunction by preserving transient OP time-frequency structure, as illustrated in preclinical rodent models and diabetic retinopathy patients.

Music is a central component of psychedelic settings, yet little experimental work has examined how psilocybin and musical composition influence music-evoked emotional responses in healthy volunteers. This exploratory, double-blind, placebo-controlled study assessed these effects during the plateau phase of psilocybin and the corresponding time window in placebo sessions following oral administration of psilocybin (0.26 mg/kg) or placebo. The study consisted of two parts. In Part 1 (n = 19), a pilot stage, the first half of participants rated music-induced affective valence for eight compositions representing different genres/subgenres (Rock/Punk, Metal/Industrial Metal, Metal/Industrial Metal, Classical/Baroque, Electronic/Dub, Folk/Nordic Folk, Electronic/Techno, Electronic/Trance, Electronic/Psytrance) using a visual analogue scale (VAS). Based on Part 1, the classical composition with the highest overall affective valence and the psytrance composition with the largest psilocybin-placebo contrast (i.e., the composition most responsive to psilocybin) were selected for Part 2 (n = 17), in which the second half of participants assessed emotional responses to music using the Geneva Emotional Music Scale (GEMS-9). Psilocybin increased wonder, transcendence, and joyful activation across both contrasting compositions. Relative to each other, the classical composition elicited greater peacefulness, tenderness, and nostalgia, whereas the psytrance composition elicited greater tension across both psilocybin and placebo conditions. A composition x condition interaction was observed for sadness: under psilocybin, sadness increased during the classical composition and decreased during the psytrance composition. These findings suggest that psilocybin and contrasting musical compositions independently influence different aspects of music-evoked emotional responses, with limited interaction effects, and point to potential implications for protocol design and music selection in psychedelic settings.

Dance is increasingly delivered as an intervention for social and affective functioning, but a live dyadic encounter confounds several distinct ingredients - social attention, verbal engagement, coordinated movement, and in-the-moment generation - so its neural effects cannot be assigned to any one of them. We recorded dual-brain mobile EEG from adult human participants of both sexes (16 female, 2 male) and a dance instructor across six five-minute conditions that vary these ingredients independently: solitary rest, direct eye gaze, conversation, teacher-led and participant-led mirroring, and free improvisation, with concurrent head-mounted accelerometry. Referencing each condition to eye gaze - socially engaging but nearly motionless - rather than to solitary rest partitioned the response. The components proved dissociable. Nonverbal social attention alone reorganized the power spectrum, flattening the aperiodic exponent (g = -0.97) and desynchronizing alpha-band oscillations (g = -0.90), while leaving inter-regional connectivity unchanged (amplitude g = +0.15; phase g = +0.11). Verbal engagement added high-frequency amplitude coupling (g = +2.61) without further spectral change. Coordinated movement added a decrease in theta/alpha coupling involving the frontoparietal-control network (g = -0.59), the signature of an externally directed state, alongside a further spectral shift (g = -0.61). Movement-vigor covariates, corticokinematic coherence, and aperiodic-adjusted power indicated that the spectral effects were cortical rather than myogenic. Four weeks of improvisational dance training increased empathic responsiveness to others' distress relative to a movie control (g = 0.82). Coordinated social movement thus acts on the brain componentially, with mutual attention rather than motor load establishing the engaged state.

The duration of visual stimuli can be altered by stimulus features, such as size, brightness, and motion. Recently, we observed that motion-induced changes in perceived duration also shift confidence judgments, but do not track awareness of the illusion. How these two effects differ and are instantiated neurally are unknown. We investigated this question by replicating our previous finding, in which human subjects (n=27) performed a temporal bisection task where they were asked to classify the duration (1-3.5s) of a walking stickman figure with different velocities and provide confidence judgments while 64-channel electroencephalogram (EEG) activity was recorded. Behavioral findings replicated the previous time dilation effect where progressively faster walking speeds led to longer perceived durations. A similar shift was observed for confidence ratings, yet with lowest confidence for the medium walking speed, indicating a metacognitive inability to monitor dilation. Furthermore, common EEG signatures of time perception, such as the late positive component of timing (LPCt) and contingent negative variation (CNV) did not vary with walking speed. Instead, onset-locked responses over occipital electrodes covaried with walking speed and correlated with subject-level shifts in psychometric functions, but not with confidence; conversely, frontocentral responses covaried with confidence judgments, but not walking speed. These findings suggest that temporal illusions are engaged by sensory processes that fail to reach the metacognitive level and that confidence judgments, in turn, are driven by motor estimates read out from frontocentral regions

Humans exhibit head movements synchronized with musical rhythms, frequently observed during instrument playing or dancing (e.g., hip hop). We conjectured that vestibular input from head movements could aid motor execution anticipatory of musical rhythms, known as sensorimotor synchronization (SMS). To examine this, we applied subthreshold galvanic vestibular stimulation (GVS) simultaneously with musical beats while healthy adults performed SMS to those beats. We designed a GVS waveform where the current rose steeply before each beat onset, which was expected to trigger intense vestibular afferent firing before the beats (as actual head movements would). Participants flexed their index finger in synchrony with the beats of syncopated auditory rhythms. In GVS trials, the SMS timing variability was significantly lower than in trials without GVS, suggesting that vestibular input stabilizes SMS to musical beats. Additionally, a control experiment using a waveform with a gradually increasing current revealed no significant difference in SMS variability between trials with and without GVS. This study provides causal evidence that the vestibular system is involved in synchronized movement to music. In addition, the results suggest that a specific parameter of the GVS waveform could influence predictive motor execution anticipatory of upcoming auditory events.

Inhibitory control is an essential executive function that encompasses both the stopping of an action in response to an unexpected stop signal (reactive response inhibition) and slowing of responses in anticipation of stopping (proactive response inhibition). Fronto-basal-ganglia circuits are thought to differentially contribute to response inhibition, with the indirect pathway implicated in proactive inhibition. Given the high expression of dopamine D2 receptors in the indirect pathway, pharmacological blockade of D2 receptors is expected to impact proactive inhibition, as indicated by response times on Go trials. The current study aimed to investigate this experimentally and study the effect of 600 mg of sulpiride, a D2 receptor antagonist, on behavioural and electrophysiological measures of proactive and reactive inhibition in humans. Human participants (N=24) completed an anticipated response version of the stop-signal task on either sulpiride or placebo in a double-blind within-subjects design. Sulpiride led to increased variability of Go response times and attenuation of the frontocentral negativity/readiness potential, considered to be a signature of proactive inhibition. In contrast, sulpiride had no effect on stop-signal reaction time or event-related potential components associated with reactive inhibition. These findings suggest that D2 receptor blockade selectively alters processes involved in proactive inhibition while leaving reactive inhibition unaffected, consistent with a key role for the indirect basal ganglia pathway in proactive response inhibition.

Comprehending a narrative requires continuously updating a model of the discourse, and beta-band activity is thought to signal when that model should be held versus changed. Whether beta also grades how much to update, and whether that index is carried by discrete bursts beyond sustained power, is unknown for naturalistic comprehension. We recorded MEG from 61 human participants (22 men, 39 women) while they listened to naturalistic Hebrew narratives, detected beta bursts in the continuous signal, and quantified the semantic shift between successive sentences from sentence embeddings. Beta burst rate decreased after sentence boundaries, and regression-based deconvolution separated a pre-onset maintenance phase from a graded post-onset response whose magnitude scaled with semantic shift (peak ~0.9 s). This response was independent of lexical surprisal, the acoustic envelope, and referent introduction, largely robust to dependency structure, though it shared variance with propositional quantity. Burst occurrence carried a component of the effect beyond the accompanying amplitude change: applying that change as a pure gain to each participant's envelope and re-running the identical detection predicts only 75% of the observed burst-rate reduction (excess p = .038), the effect survived an amplitude-invariant threshold, and a Poisson model reproduced it as a graded reduction in burst-initiation rate. The effect held in both participant groups, which heard differently framed narratives, and was decisively supported (BF10 > 250). Beta bursts thus provide a graded signal of semantic updating during continuous comprehension, expressed in the rate of burst occurrence over and above the accompanying change in sustained power.

Reduced visibility is a common contributor to falls in older adults, but the neural processes that support safe locomotion under low lighting are not well established. In this study, 22 young (mean age = 22.5) and 20 older (mean age = 70.9) adults walked along a pathway under bright, ambient and dark lighting conditions while stepping over expected and unexpected obstacles projected on the floor. Mobile electroencephalography (EEG), combined with motion capture, was used to quantify spectral power changes during obstacle crossing preparation and the post-crossing phases, relative to a standing baseline. We identified that reduced lighting conditions elicited a widespread increase in cortical engagement, predominantly in the alpha band, during both preparation and reset phases. Obstacle negotiation recruited a distributed sensorimotor network, with reduced theta-alpha-beta desynchronisation during preparation and a robust post-movement beta rebound during the post-crossing reset phase. Expectation effects were modest, with unexpected obstacles inducing greater transient alpha-beta desynchronisation relative to expected obstacles, suggesting additional cortical resources are recruited under uncertainty. Age effects were minimal and limited to reduced frontal alpha desynchronisation in older adults compared to young adults during the preparation phase, possibly reflecting differences in walking speed rather than differences in neural control. In conclusion, environmental features such as low lighting and obstacle presence exert a stronger influence on cortical dynamics during walking than age and expectation effects alone. This provides a foundation for future work examining how these processes may differ in older adults at increased risk of falls.

Mild cognitive impairment (MCI) may involve impaired dynamic regulation of brain states that is not captured by conventional resting-state electroencephalography (EEG). We quantified occipital alpha (8-12 Hz) transitions during three repeated eye-opening/eye-closure cycles in 60 healthy controls (HC) and 77 participants with MCI. Eye-state events were refined from frontal ocular artifacts. Transition magnitude was measured by the log-transformed post-/pre-event energy ratio, and transition success by the expected direction of alpha change. For canonical transitions meeting prespecified fit-quality criteria, mono-exponential fitting yielded transition onset (t_onset) and the post-onset time constant (tau). MCI showed weaker alpha suppression during eye opening, weaker alpha enhancement during eye closure, and lower odds of transition success. No significant group difference in tau was detected within the canonical quality-controlled subset. In contrast, t_onset showed significant Group x Trial interactions in both conditions: HC developed later onset during eye opening and earlier onset during eye closure across repetitions, whereas MCI showed no comparable change. These findings suggest reduced alpha state-transition capacity and altered repetition-dependent temporal organization in MCI.

Introduction: Observation of a partner in pain elicits empathy-related cortical responses and social support can modulate pain. Objective: The aim of this study was to investigate empathy and the cortical response during observation of a romantic partner in pain with and without consoling touch. Methods: A total of 40 participants (20 couples) completed validated measures of handedness, pain and empathy. Each member of the couple was randomly assigned to be either the recipient of cold pressor pain or the consoling partner undergoing EEG. EEG activity was recorded from the consoling partner during baseline and pain conditions (with and without consoling touch) to investigate how observation of a partner in pain could alter mu rhythms. Results: Observing a romantic partner in pain significantly enhanced mu at electrodes C4 and Cz, yet addition of consoling touch did not significantly change mu rhythms. Personal Distress was positively associated with mu rhythm enhancement at electrode C4 during pain without consoling touch (r = .576, p = .008). Conclusion: Viewing a romantic partner in pain significantly increased mu rhythms, that was not further changed by offering consoling touch. The association between increases in mu rhythms and Personal Distress in the current study suggests that self-oriented distress may be especially relevant to sensorimotor cortex responses when witnessing a partner in pain, particularly when consoling touch is not possible. Keywords: pain; empathy, EEG, mu rhythms, cold pressor