Frontiers in Human Neuroscience最新文献

The logopenic variant of Primary Progressive Aphasia (lvPPA) is marked by phonological short-term memory deficits that compromise repetition and communication. While previous interventions in PPA have primarily targeted lexical-semantic abilities, little is known about therapies that directly address phonological impairments, primarily through teletherapy. This first study investigated the efficacy of an intensive phonological short-term memory training program delivered via teletherapy in individuals with the lvPPA. The intervention aimed to improve repetition of trained items, promote generalization to untrained items, facilitate transfer to functional tasks, and ensure maintenance over time. In the present study, significant improvements were observed in both immediate and delayed repetition of trained items, with partial short-term generalization to untrained items, particularly for words in delayed tasks. No substantial generalization effects were observed for functional language tasks, including picture description and picture naming, suggesting that the intervention's impact may remain task specific. Individual trajectories revealed heterogeneous responses, potentially influenced by baseline cognitive profiles, spontaneous strategies, or fatigue. Mixed-effects models confirmed that interindividual factors explained a substantial portion of the variance. These findings support the feasibility and clinical relevance of remote phonological training in the lvPPA and underline the importance of early, personalized interventions. The study also raises the hypothesis that delayed repetition may facilitate internal rehearsal, enhancing generalization. Further research is needed to assess broader functional outcomes and optimize protocol scalability.

Introduction: Cognitive dysfunction is a chronic and debilitating element of major depressive disorder (MDD), which manifests as abnormal processing in hot (emotion-laden) and cold (emotion-independent) cognitive systems. Although the antidepressant properties of repetitive transcranial magnetic stimulation (rTMS) are well-established, its impact on hot and cold cognition requires further elucidation.

Methods: Prospective study of patients with MDD undergoing an acute course of high frequency rTMS to the left dorsolateral prefrontal cortex (L-DLPFC). MDD patients (N = 24) received a 4-to-6-week course of rTMS during which they were evaluated for depressive symptoms and completed cognitive assessments. Age-, sex-, and education-matched healthy controls (N = 33) also completed the cognitive tasks at the same intervals as the MDD patients.

Results: Sustained antidepressant effect was observed following rTMS in MDD patients. Hot and cold cognition remained unaltered over the course of treatment. A pre-treatment baseline cognitive phenotype of those who achieve remission of their depressive symptoms with rTMS was identified, characterized by greater sustained attention, speed in correct identification of facial expressions, and free recall of words.

Conclusion: Our findings further validate the cognitive safety and clinical efficacy of rTMS as an intervention for MDD. Future research is required to further characterize the utility of pre-rTMS cognitive phenotyping in identified remitters, to aid in patient selection and treatment prognostication.

Introduction: The purpose of the study was to investigate potential differences in contralateral muscle excitation in proximal versus distal muscles in the upper extremities. Based on the different neuroanatomical and neurophysiological constraints in the central part of the neural system for proximal and distal muscles, it was hypothesized that contralateral muscle excitation (CME) would be higher for proximal than distal muscles.

Methods: Thirteen university students participated in this study. The participants performed isometric flexion movements with the shoulder and index finger of the dominant arm at four different relative force levels (25, 50, 75, 100%). Force was measured with a force transducer connected to the index finger and elbow on the dominant arm. Muscle excitation was measured using sEMG placed on the flexor carpi radialis (distal condition) and the anterior deltoid (proximal condition) on the non-dominant arm.

Results: CME was observed in both proximal and distal muscles, with proximal muscles displaying significantly higher CME at higher force levels (50, 75, and 100%). In the proximal condition, contractions with the dominant anterior deltoid were associated with a progressive increase in CME across force levels in the contralateral homologous muscle. In contrast, for the distal condition (flexor carpi radialis), CME changes were only evident when comparing the lowest and highest force levels.

Conclusion: The results are in coherence with the differences in neuroanatomical and neurophysiological constraints for bilateral communication for proximal versus distal muscles. The present results encourage further neurophysiological studies using direct brain activity measures to explore the potential link between the differences in bilateral communication and CME for proximal versus distal muscles.

Introduction: Complex regional pain syndrome (CRPS) is often associated with pain-related fear of movement, and virtual reality has been proposed as a potential rehabilitation intervention to overcome this issue. Therefore, this cross-sectional study aimed to test whether altering the visual feedback (VF) on movement could mitigate pain and promote movement.

Methods: Fifteen participants with upper-limb CRPS and 15 age- and gender-matched pain-free participants undertook a target reaching task in the Kinarm exoskeleton, with two VF conditions being tested (Per Exposure: GREATER or SMALLER VF; two separate sessions), preceded and followed by reaching movements without VF (Pre-/Post-Exposure). Proprioception was assessed with a Limb Position Sense task, and a Movement Accuracy outcome was derived from the Pre-Exposure reaching movements.

Results: Contrary to our hypothesis, pain intensity was not influenced by VF conditions but increased over Time (p < 0.001). Analyses performed on kinematics data showed that participants displayed visuomotor adaptation both Per Exposure, and Pre-/Post-Exposure to altered VF (VF condition^*Time: p < 0.001). Per Exposure analyses revealed that CRPS participants tended to adapt their Movement Length to a lesser extent than pain-free participants (Group^*VF condition: p = 0.048). Pre-/Post-Exposure analyses revealed that CRPS participants consistently performed larger movements than pain-free participants (p = 0.002). Both groups performed similarly for the Limb Position Sense task, but CRPS participants displayed significantly larger errors for Movement Accuracy, suggesting impaired proprioceptive integration in the CRPS group.

Discussion: These findings support the idea that visuomotor adaptation is preserved in CRPS and can be used to promote movement.

In everyday vision, we often shift attention internally without external cues. These self-initiated attention shifts are fundamental to voluntary behavior but are poorly understood because most studies use cue-based paradigms that predetermine when and where to shift attention. To address this gap, we designed a multi-sequential-choice rapid serial visual presentation (RSVP) paradigm with identical visual inputs to dissociate internal and external determinants of attention across three voluntary shift types: task-constrained self-initiated, externally instructed, and unconstrained free-viewing. Participants viewed four simultaneous streams of letters and made overt attention shifts among them, while EEG was recorded. We time-locked theta (4-7 Hz) and alpha (8-12 Hz) oscillations to shift onset and found distinct signatures for each condition. Notably, a frontal-midline theta ramping was observed before self-initiated shifts but not before instructed or free-viewing shifts, suggesting a preparatory buildup of cognitive control specific to internally driven shifts. Concurrently, sustained suppression of posterior alpha occurred before self-initiated shifts. In contrast, instructed and free-viewing shifts showed relatively higher posterior alpha. These findings suggest that internally generated, goal-driven shifts engage an anticipatory frontal control mechanism indexed by theta increase and reduce posterior inhibition, whereas externally cued or unguided shifts do not. By isolating these condition-specific neural dynamics under identical external stimuli, our study identifies a unique oscillatory signature, frontal-midline theta ramping, associated with task-constrained self-initiated attention shifts.

Background: Cancer-related cognitive impairment (CRCI) is relatively common among middle-aged and older adult cancer patients, with working memory deficits being particularly prominent. However, the underlying structural basis of hippocampal subregions remains unclear. This study aimed to investigate differences in hippocampal subfield volumes and working memory function between cancer patients and healthy controls, as well as to analyze the correlation between hippocampal structural alterations and working memory impairment.

Methods: The cohort comprised 51 cancer patients and 45 healthy controls. All participants underwent 3D-T1 structural MRI scans and cognitive assessments. Hippocampal subfields were automatically segmented using FreeSurfer 7.4, and their volumes were calculated. Group differences in cognitive test scores were compared. After controlling for total intracranial volume (TIV), analysis of covariance (ANCOVA) was performed to examine differences in hippocampal subfield volumes between groups. Spearman correlation analysis was undertaken to assess the relationship between hippocampal subfield volumes and cognitive test scores in patients with cancer.

Results: Compared with healthy controls, cancer patients exhibited significantly lower scores in the digit span test (DST) total score (U = 716.50, p = 0.001) and digit span forward (DSF) subtest (U = 738.50, p = 0.002). Hippocampal subfield analysis revealed significant volume reductions in the cancer group, particularly in CA3 (F = 8.141, p = 0.005) and CA4 (F = 6.770, p = 0.011). Correlation analysis demonstrated that the volumes of the hippocampal head (r = 0.410, p = 0.003) and hippocampal molecular layer (r = 0.389, p = 0.005) were positively associated with DST scores in cancer patients.

Conclusion: Cancer patients exhibit working memory impairment and hippocampal subfield atrophy. The significant correlation between the volumes of the hippocampal head and molecular layer with working memory performance suggests that these regions may play a critical role in cancer-related cognitive dysfunction.

The purpose of this study is to provide basic data for the establishment of sustainable sports content and communication marketing strategies of effective OTT platforms by applying the extended technology acceptance model to clarify the causal relationship between the perceived usefulness, perceived ease of use, perceived enjoyment, perceived interactivity, usage intention, and usage behavior of users who watch OTT platform sports content. To achieve this purpose, 303 viewers with experience watching OTT platform sports content were used for the analysis. The data analysis methods were frequency analysis, correlation analysis, confirmatory factor analysis, and structural equation modeling analysis using SPSS 21.0 and AMOS 18.0. The results of this study are as follows. First, perceived usefulness was found to have no significant effect on usage intention. Second, perceived ease of use was found to have a significant effect on usage intention. Third, perceived enjoyment was found to have a significant effect on usage intention. Fourth, perceived interactivity was found to have a significant effect on usage intention. Fifth, usage intention was found to have a significant effect on usage behavior. Therefore, the intention of using OTT platform sports content will be to become a sustainable industry in terms of media business.

Introduction: Stroke ranks as the second leading cause of death and disability worldwide, with the resulting upper-limb spasticity severely impairing patients' motor function and quality of life. However, existing clinical assessment scales exhibit a degree of subjectivity, and research into the neurophysiological mechanisms underlying spasticity remains insufficient. Brain network analysis offers a novel perspective for investigating the neural mechanisms associated with spasticity.

Methods: Eight patients with upper limb spasticity due to stroke (MAS grades 1-2) and eight healthy controls were enrolled. Multi-channel EEG signals were recorded during different upper limb movements (fist clenching, elbow flexion, wrist flexion). Functional brain networks were constructed using the weighted phase delay index, and further calculations were performed on relevant brain network characteristics, including node degree, global efficiency, local efficiency, clustering coefficient, and small-world properties.

Results: Research findings indicate that functional connectivity in spasticity patients is significantly lower than in healthy subjects, particularly in the alpha and beta frequency bands, with weaker cross-regional synchrony in frontal, central, and temporal lobe regions. Graph theory analysis further reveals that compared to healthy controls, spasticity patients exhibit significantly reduced global efficiency, local efficiency, and clustering coefficient, while small-world properties remain relatively preserved. Node degree analysis revealed abnormal compensatory activation in temporal and parietal regions, whereas healthy participants exhibited higher node degrees in central and frontal areas. These findings suggest that spasticity is associated with impaired local and global network integration, accompanied by inefficient compensatory mechanisms.

Discussion: This study provides new evidence that post-stroke upper limb spasticity is not only a peripheral muscle phenomenon but also reflects disturbances in cortical network dynamics. Brain network metrics, particularly global and local efficiency, may serve as objective biomarkers to quantify spasticity severity and guide personalized rehabilitation interventions, offering a promising direction for developing precision rehabilitation strategies.