Background Sensorimotor stimulation has been shown to protect against brain damage and function impairments following experimental Cerebral Palsy (CP). Functional ultrasound (fUS) gives valuable information about brain connectivity at unprecedented spatial and time resolutions with high translational potential. We tested brain function and connectivity using fUS following experimental CP and the effects of early sensorimotor rehabilitation in the model. Methods Pregnant Wistar rats were exposed to maternal immune challenge at E18-19. Pups received perinatal anoxia at postnatal day 0 (P0) and restriction of the hindlimbs from P2 to P21. Rehabilitation (EETT) used environmental enrichment (EE) and Treadmill Training (TT) from P21 to P28. At P29, fUS was performed to access brain connectivity and graph theoretic analysis was used to distinguish patterns of brain connectivity. Results CP increased intrinsic brain functional connectivity compared to Controls and EETT animals. Connectivity was increased in CP animals in cortical areas related to sensorimotor function and subcortical myelinated structures. EETT animals showed levels of brain connectivity similar to Controls. Conclusions Sensorimotor stimulation changed brain hyperconnectivity profile induced by CP. Brain connectivity pattern alterations can be detected using fUS with high accuracy, suggesting great potential to be used as earlier biomarker for neurodevelopmentalal disorders such as CP.

Functional near-infrared spectroscopy (fNIRS) and functional magnetic resonance imaging (fMRI) both rely on the phenomenon of neurovascular coupling (NVC) to probe brain activity through their sensitivity to cerebral blood oxygenation. However, the relationship between fNIRS chromophores (oxy- and deoxyhaemoglobin, HbO and HbR), and fMRI (Blood Oxygen Level Dependent and Arterial Spin Labeling, BOLD and ASL) measurements, and whether this relationship remains consistent across subjects and physiological conditions, has only been partially characterised. We acquired concurrent continuous-wave fNIRS and gradient-echo (GE) and spin-echo (SE) BOLD-ASL fMRI in healthy adults (n = 10) during visual stimulation. By applying calibrated fMRI methodology, we examined the relationships between fNIRS-derived haemoglobin modulations and fMRI-derived modulations in macrovascular (GE-) and microvascular (SE-) BOLD signals, cerebral blood flow (CBF), and oxygen metabolism (CMRO₂). Group-level results showed strong temporal cross-modal agreement, with HbO and HbR tightly mirroring all fMRI signal time-courses (|r| > 0.8). A quantitative analysis of trial-by-trial modulations revealed distinct state-dependent behaviours: HbO maintained a stable relationship with the fMRI-derived metrics across conditions, whereas cross-modal relationships between HbR and fMRI-derived metrics substantially strengthened at higher flow-metabolism coupling (FMC), the ratio of CBF to CMRO₂ change, an index of the strength of NVC. Both HbO and HbR were more strongly associated with GE-BOLD than with SE-BOLD. These findings provide a rigorous physiological grounding for fNIRS signal interpretation, demonstrating its utility as a surrogate marker for specific haemodynamic and metabolic parameters.

Anorexia nervosa (AN) is a somato-psychiatric disease that mostly begins in adolescence, involving endocrine changes including amenorrhea. It is difficult to treat as most patients have difficulties embracing change and thus, the disease often takes a chronic course. Underlying pathomechanisms including moderate neuropsychological deficits of learning and memory remain insufficiently understood. As learning and memory have been shown to be estradiol-dependent in healthy controls (HC), we conducted this assessment to investigate the impact of reduced estradiol in patients on verbal learning, memory and the underlying brain-alterations.

Mapping functional brain organization between species is a prerequisite for translating connectivity biomarkers from animal models to patients, but connectivity-based correspondence has been demonstrated almost exclusively in primates. We tested whether canine-human network homology can be recovered from functional connectivity alone, using only five network-level anatomical priors, and benchmarked a spectral manifold alignment framework (Laplacian-eigenmap embedding with Procrustes alignment on network centroids) against a simple connectivity-signature matching baseline. Data comprised resting-state fMRI from 15 canines with endovascular permanent middle cerebral artery occlusion (pre-occlusion baseline and hyperacute post-occlusion sessions) and two public OpenNeuro datasets: 29 chronic-phase post-stroke aphasia patients scanned before and after rehabilitation (ds003999) and 10 healthy controls (ds000224). Held-out canine-human network homologies were recovered well above chance (top-5 network correspondence up to 54.5% vs. permutation null ≈ 18%, p = 0.002), and correspondence followed the evolutionary cortical hierarchy: visual and somatomotor homologies were recovered several-fold above chance, default-mode only weakly-extending a gradient previously described in primates to a carnivore. Notably, simple signature matching (54.5%) outperformed manifold alignment (35.5%), indicating that the homology signal is strong enough to be captured without embedding machinery at translational cohort sizes. Within species, canine network metrics showed no treatment-arm differences (all p > 0.3), and chronic-phase patients did not differ from controls in modularity (p = 0.93); a sensitivity analysis bounds these nulls. All results are fully reproducible from shared code and public data.

Repeated occupational exposure to low-level blast may pose a risk to the neurological health of service members. To date, no studies have specifically investigated the effects of such repetitive exposure using fluorodeoxyglucose positron emission tomography (FDG-PET). This study aims to characterize cerebral metabolic alterations associated with occupational blast exposure, accounting for confounding factors such as posttraumatic stress disorder (PTSD) symptoms and aging. Male service members with chronic mild TBI (mTBI) were categorized into high-risk (HR; n = 204) and low-risk (LR; n = 68) blast exposure groups based on their military occupational specialty. FDG-PET and diffusion tensor imaging (DTI) data were analyzed using region-of-interest (ROI) and voxelwise methods. Statistical models included age and PTSD symptom severity as covariates. Compared to the LR group, ROI analyses revealed higher FDG uptake in the left pallidum, caudate, and ventrolateral prefrontal cortex in the HR group. These elevations in metabolic activity may reflect compensatory mechanisms in response to neurophysiological disruption following blast exposure. Voxelwise analysis showed lower FDG uptake in the HR group within white matter, predominantly in the right hemisphere, including the corpus callosum, anterior thalamic radiation, inferior and superior longitudinal fasciculi. Corresponding DTI findings showed higher fractional anisotropy (p = 0.0025) and axial diffusivity (p = 0.024) in these regions. Furthermore, leftward metabolic lateralization was observed in the pallidum, with the HR group (Cohen's d = 1.36, 95% CI [1.14, 1.57]) exhibiting greater metabolic asymmetry than the LR group (Cohen's d = 1.16, 95% CI [0.79, 1.51]). Findings from this study reveal metabolic and microstructural alterations associated with occupational blast exposure in service members with mTBI.

Motor observation and motor imagery (MOMI) has been increasingly utilized in motor learning and neurorehabilitation research; however, it remains unclear whether different temporal arrangements of observation and imagery are reflected in distinct brain network organization. Therefore, the present study investigated whether asynchronous and synchronous MOMI exhibit distinct network-level patterns during motor simulation. To isolate the effect of temporal organization while maintaining a constant motor task context, participants performed a basketball set-shot task, allowing comparison among asynchronous MOMI (A-MOMI), synchronous MOMI (S-MOMI), and motor imagery (MI). Phase-locking value (PLV)-based functional connectivity analyses revealed significant condition-related differences, predominantly within the theta, alpha, and beta frequency bands. Specifically, MI exhibited stronger theta-band functional connectivity during the early phase of the task, whereas A-MOMI demonstrated more sustained enhancement of alpha-band connectivity during the middle and later phases. Furthermore, coupling between theta phase and 12-16 Hz amplitude was stronger in A-MOMI compared to both S-MOMI and MI. Decoding analysis further indicated moderate separability among the three conditions, yielding an overall classification accuracy of 69.61%. A-MOMI achieved the highest classification accuracy (79.41%), followed by MI (73.53%) and S-MOMI (55.88%), reflecting differential discriminability among the conditions. Collectively, these findings provide network-level evidence that the temporal organization of observation and imagery shapes MOMI-related brain network organization, with implications for optimizing motor training protocols and EEG-based assessments of motor simulation states.

We examined focus-relative amyloid PET asymmetry and its associations with resting-state EEG connectivity and processing speed in mesial temporal lobe epilepsy (MTLE). Thirty adults with clinically assigned MTLE (19 right-focus, 11 left-focus) underwent [18]F-florapronol PET and resting-state EEG. Regional standardized uptake value ratios (SUVRs) and sensor-level weighted phase lag index (wPLI) were evaluated using paired comparisons, rank correlations and exploratory bootstrap indirect-association models. Cognitive data were available for 26 participants, including Digit Symbol Coding (DSC) for 25. Under the original analytical convention, mean medial temporal SUVR was 1.066 ipsilaterally and 1.013 contralaterally (difference 0.053, 95% CI [0.013, 0.093]; p = 0.011; Cohen's dz = 0.500). The contrast differed by focus side (interaction p = 0.002) and was 0.038 under source-table reconstruction (p = 0.075). Ipsilateral SUVR correlated with inter-hemispheric beta wPLI (ρ = 0.617, q = 0.034 across 240 tests). The intra-contralateral association (ρ = 0.536) did not survive this broader correction. Indirect estimates for Trail Making Test A (0.279, 95% bootstrap CI [0.043, 0.761]) and DSC (0.151, 95% bootstrap CI [-0.114, 0.476]) did not survive correction across 136 models. Regional medial temporal PET uptake was associated with beta-band scalp connectivity in this small cohort, while focus-side heterogeneity and labeling sensitivity limit a uniform ipsilateral interpretation. Processing-speed indirect associations were exploratory and did not establish compensation or causality. Replication with structural correction, longer EEG sampling and longitudinal cognitive follow-up is required.

In noisy listening environments, visual cues from a speaker's face can significantly boost speech comprehension. The underlying audiovisual integration in the brain involves tracking of audiovisual speech features in the temporal lobe. Moreover, lip reading in silence is associated with tracking of the speech envelope in the low-delta frequency band (0.5-1 Hz). Recently, digital avatars have emerged that can support speech comprehension. Yet, it remains unclear how the human brain integrates such artificial visual signals with natural speech. Here, we employed magnetoencephalography (MEG) to measure the neural responses to a natural video, an avatar generated by deep neural networks, and a degraded video serving as a control. We demonstrate that the avatar can enhance speech-in-noise comprehension to a similar degree as the degraded video, although less than the natural video. We further identify a late response at 600 ms of the neural tracking in the high delta band (1-4 Hz) that predicts audiovisual speech comprehension. In contrast, we did not find the neural tracking in the theta band to be involved in audiovisual integration. Interestingly, we further found that neural tracking in the low delta band was related to silent lip-reading performance. Moreover, the tracking in the low delta band evoked by the avatars was much weaker and occurred earlier than that elicited by the other audiovisual stimuli. Our results show that audiovisual integration can take place even later than suggested in previous work and can index speech understanding. Additionally, the low delta band and the high delta band play distinct roles in visual-only and audiovisual speech processing, suggesting potential avenues for further boosting the abilities of avatars to support speech comprehension.

Allocentric spatial navigation declines with age, but the underlying neural mechanisms remain unclear. The posterior cingulate/retrosplenial cortex (PCC/RSC) is an integrative navigation hub and is also among the earliest regions affected by aging. We investigated whether the PCC/RSC is organized along continuous functional connectivity gradients, and how these gradients relate to age and spatial navigation ability. Using an adult-lifespan sample from the Southwest University Adult Lifespan Dataset (SALD; n = 479; age range = 19-80 years), we characterized functional connectivity gradients within the PCC/RSC complex and examined their associations with age. Two dominant functional connectivity gradients (G1 and G2) were identified within the PCC/RSC complex. The ranges of both gradients decreased significantly with age. In an independent navigation sample comprising 19 younger and 19 older adults, participants underwent resting-state fMRI and task-based fMRI while performing an allocentric object-location memory task. We examined whether age-related gradient compression was also evident in this independent navigation sample and whether gradient range was associated with navigation performance. Older adults showed smaller task-state left G1, task-state right G2, and resting-state right G2 ranges, with the largest reduction in task-state left G1 (approximately 65%). Among older adults, greater task-state left G1 range was associated with lower drop error. These findings provide novel evidence that age-related compression of PCC/RSC functional organization is behaviorally relevant to allocentric navigation decline.

Perceptual judgments are biased toward recent experience, a phenomenon called serial dependence. For orientation and motion, this carryover has a demonstrated locus in the early visual cortex; for time, the circuits that hold the previous duration are unknown. Using fMRI, we asked where the preceding duration is represented, and whether the same neural mechanism carries recent information about a non-temporal feature of the same stimulus. Participants viewed a moving random-dot display and reproduced either its duration or its direction, retro-cued as to which feature to report, thereby separating the memory trace from the demands of task switching. Duration reproduction was attracted toward the preceding duration, four times more strongly when the same task was repeated. Direction judgments exhibited a much smaller bias that reversed sign with the preceding task. The preceding duration was negatively associated with retro-cue-locked activity in the bilateral putamen, the region where this effect survived whole-brain correction. The estimate held after accounting for both current and preceding responses. Direction produced no comparable signal anywhere. Switching from the direction task to the time task recruited the inferior frontal junction and dorsolateral prefrontal cortex, neither of which carried a preceding-duration effect. The prior-duration signal, therefore, localized to the dorsal striatum, distinct from the frontoparietal regions in task reconfiguration. These findings argue against a unitary neural mechanism for serial dependence and suggest that recent-history biases are likely domain-specific: for perceived time, the critical trace resides in the striatum rather than in the visual cortex.