Experimental Brain Research最新文献

{"title":"Immediate effects of binaural beat stimulation on prefrontal cortical activation after cycling exercise: an electroencephalography-based study.","authors":"Shih-Fen Hsiao, Tzu-Ling Liu, Yu-Chen Lin, Chen-Wen Yen, Ka-Chun Siu, Jau-Hong Lin","doi":"10.1007/s00221-026-07387-7","DOIUrl":"10.1007/s00221-026-07387-7","url":null,"abstract":"<p><p>Binaural beat stimulation (BBS) has been shown to activate the cerebral cortex and promote physical and mental relaxation. This study investigated the immediate effects of theta-frequency BBS following cycling exercise on prefrontal cortical activation in healthy adults. Sixty healthy adults were recruited from the community using convenient sampling. Each participant completed a 20-min cycling exercise on two consecutive days. In a randomized order, one day was followed by a 20-min wide-band theta-frequency (5.5-8.5 Hz) BBS combined with pink noise and the other day by a sham BBS intervention. An eight-channel dry-electrode electroencephalography system was used to record the changes of prefrontal cortical activation at six time points before and after the cycling exercise. A total of 52 participants completed the study. Compared to the sham stimulus, the theta-frequency BBS combined with pink noise significantly enhanced the theta and alpha wave powers. Power changes in the left and right prefrontal cortices and the frontal midline regions (r=0.28-0.51, p<0.05) across multiple time points indicated an immediate enhancement of prefrontal cortical activation. This preliminary study suggests that receiving wide-band theta-frequency BBS after20 minutes of cycling exercise may modulate prefrontal cortex activity. Given its non-invasive and simple nature, BBS warrants further exploratory research to determine its potential role as a supplementary tool in post-exercise recovery strategies.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 10","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148863807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cervicothoracic trans-spinal magnetic stimulation: effect of coil position and orientation on spinal motor evoked potentials.","authors":"Lei Zhu, Sophia G Nopoulos, Kesten M Anderson, Richard K Shields, Stacey L DeJong","doi":"10.1007/s00221-026-07390-y","DOIUrl":"10.1007/s00221-026-07390-y","url":null,"abstract":"<p><p>Stroke is a leading cause of long-term adult disability, and over 80% of survivors have persistent upper limb motor impairment. Spinal electrical stimulation has shown therapeutic potential after neurological disorders. Post-stroke applications have largely relied on invasive implants that limit clinical adoption, and non-invasive high intensity electrical stimulation may be intolerable for those with residual sensory function. Trans-spinal magnetic stimulation offers a non-invasive alternative capable of modulating residual sensorimotor pathways. Fundamental parameters, such as coil position and orientation, remain under-investigated. Two experiments were conducted to fill this gap. Experiment 1: 19 healthy adults underwent spinal mapping involving 30 cervicothoracic sites (3×10 grid). Responses were recorded from 6 upper limb muscles bilaterally at suprathreshold intensity using a rostral-left induced current direction. Friedman ANOVAs revealed significant medial-lateral and rostral-caudal variation in amplitude of spinal motor evoked potentials (sMEPs): ipsilateral>midline>contralateral, with arm responses peaking rostrally, wrist at mid-rows, and hand caudally. Experiment 2: 20 healthy adults received stimulation at three horizontal cervicothoracic sites using eight current directions spaced 45° apart. Friedman ANOVAs indicated a bilateral mirror-symmetrical pattern. The largest responses from left-sided muscles were elicited with a rostral-left current direction achieved by rotating the coil handle 45° counterclockwise from the caudal direction. Likewise, the largest right-sided muscle responses were elicited with a rostral-right current direction achieved by rotating the coil handle 315° counterclockwise. Coil position and orientation are critical determinants of sMEP amplitude. These results provide a foundational framework to further investigate cervicothoracic magnetic stimulation as a potential non-invasive neuromodulatory intervention.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 10","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13529895/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148863105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age-related differences in embodying a tool under visual deprivation.","authors":"Amir Jahanian Najafabadi, Bernhard Hommel","doi":"10.1007/s00221-026-07382-y","DOIUrl":"10.1007/s00221-026-07382-y","url":null,"abstract":"<p><p>Tool embodiment refers to the integration of external objects into action-related body representations. Although vision is often assumed to support this process, it remains unclear how tool use under short-term visual deprivation affects explicit ownership and agency across the adult lifespan. This study examined whether blindfolded cane use elicits subjective ownership and agency in younger and older adults, and whether these experiences are associated with forearm tactile distance perception and perceived reaching distance. Forty-three healthy right-handed adults completed two blindfolded cane-use conditions: object search training and navigation training. Tactile Distance Judgment and Reaching Distance Estimation tasks were administered before and after cane use, and participants rated ownership and agency after each condition. Across age groups and conditions, agency ratings were consistently stronger than ownership ratings. Regression analyses indicated that behavioral recalibration measures, especially Reaching Distance Estimation Error, were more consistently associated with agency than ownership, with the clearest joint-model effect observed for agency during navigation. Age Group also contributed to agency during navigation, although age-dependent interaction effects did not reach statistical significance. These findings suggest that short-term blindfolded cane use can support explicit action-based control over a tool without necessarily producing a strong conscious feeling that the tool belongs to the body. The results highlight a dissociation between explicit ownership, agency, and behavioral indices of tool-related sensorimotor updating under blindfolded tool use.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 10","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13525023/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148850126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proximo-distal gradient of spinal recurrent inhibition: implications for motor pool fractionation and dexterity.","authors":"Alessandro Rossi","doi":"10.1007/s00221-026-07386-8","DOIUrl":"10.1007/s00221-026-07386-8","url":null,"abstract":"<p><p>Spinal recurrent inhibition (RI), mediated by Renshaw cells, exhibits a highly conserved proximal-to-distal gradient across mammals: it is robust in proximal motoneuron (MN) pools but absent in MNs innervating both extrinsic and intrinsic digit muscles. Although this organizational pattern has been recognised for more than six decades, its mechanistic basis has remained unexplained. The widely accepted view that the gradient reflects the evolutionary emergence of monosynaptic corticomotoneuronal (CM) projections is challenged by the cat, which lacks monosynaptic CM input to digit MNs yet exhibits the same RI gradient observed in primates. We performed a comparative quantitative analysis of 16 published MN pools from humans, macaque monkeys, and cats. Four nested nonlinear regression models and a Bayesian hierarchical errors-in-variables model were used to evaluate the relative contributions of CM input and recurrent collateral density to normalised RI strength. The robustness of the CM contribution was assessed through Bayesian prior sensitivity analyses using both HalfNormal and symmetric Normal priors. Recurrent collateral density provided the strongest explanation for the conserved RI gradient, accounting for 97.7% of the cross-species variance (NLS R² = 0.977; ΔAIC = 53.6 relative to the CM-only model; Bayesian R² ≈ 0.975). Bayesian analyses consistently supported a positive, although quantitatively modest, contribution of CM input across all prior specifications, indicating that direct corticospinal connectivity refines but does not determine the distribution of RI. The cat therefore constitutes a decisive natural experiment demonstrating that the conserved RI gradient cannot be explained by the presence or absence of monosynaptic CM projections alone. These findings support the Motor Pool Fractionation Hypothesis (MPFH). Recurrent inhibition retains its established physiological role in regulating motoneuronal excitability and motor output; however, its selective anatomical distribution across motor pools appears to have an additional organizational significance. The absence of RI from digit MN pools creates a permissive spinal substrate for motor-pool fractionation, whereas the presence of direct CM connectivity represents a later evolutionary specialization that exploits and amplifies this pre-existing spinal organization to achieve highly fractionated motor control. The marked difference between human hand and foot dexterity is therefore interpreted as reflecting differences in corticospinal network coverage rather than differences in the spinal inhibitory substrate itself.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 9","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148826684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disrupted proprioceptive timing estimates contribute to upper limb motor impairment in chronic stroke.","authors":"Devin S Austin, Arianna G Eimont, Jennifer A Semrau","doi":"10.1007/s00221-026-07378-8","DOIUrl":"10.1007/s00221-026-07378-8","url":null,"abstract":"<p><p>In this task, the participants' (p < 0.01) and variability (p < 0.01) than controls, indicating impaired proprioceptive timing in a task that did not require active motor output from the tested limb. Larger proprioceptive timing errors were strongly correlated with poor performance on VGR (ρ > 0.57, p < 0.01) and APM in individuals with stroke (ρ > 0.49, p < 0.01). These results suggest that the estimation of timing for dynamic sensory signals is disrupted in individuals with stroke and likely contributes to dysfunction in coordinated movement and static estimations of limb position.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 9","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13506565/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148817465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: Explicitly acquired interrelations among mental schema reduces cognitive load and facilitates emergence of novel responses in mice and artificial neural networks.","authors":"Vikram Pal Singh, Shruti Shridhar, Sankhanava Kundu, Richa Bhatt, Balaji Jayaprakash","doi":"10.1007/s00221-026-07373-z","DOIUrl":"10.1007/s00221-026-07373-z","url":null,"abstract":"","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 9","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148812501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LC-MS-based metabolomics reveals the In Vivo effects of cognitive formula 1 in rats with Aβ-induced Alzheimer's disease.","authors":"Di Wu, Yanling Lin, Wenjun Guo, Zengling Wang, Yan Chang, Jing Yan, Daqing Han, Ke Xiang, Zhen Yang","doi":"10.1007/s00221-026-07364-0","DOIUrl":"10.1007/s00221-026-07364-0","url":null,"abstract":"<p><p>Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive impairment of cognition, behavior, and functional abilities that can ultimately lead to death. Cognitive Formula 1 (CF1), a traditional Chinese medicine (TCM) formulation, has demonstrated promising therapeutic efficacy in clinical applications. However, the precise mechanisms underlying its therapeutic effects in AD remain unclear. An AD rat model was established by intracerebral injection of amyloid-β peptide 1-42 (Aβ₁₋₄₂) to investigate the mechanism of CF1. The results indicated that synergistic interactions among multiple CF1 components influence host metabolic pathways, in particular those involved in glycerophospholipid and amino acid metabolism, thereby suggesting an explanation for the alleviation of systemic metabolic dysregulation by the formulation. CF1 also remodeled the gut microbiota by reducing the abundance of potentially detrimental bacteria, such as Veillonella and Lachnoclostridium, while enhancing that of beneficial bacteria, such as Roseburia. These changes improved intestinal homeostasis, reduced endotoxin influx, and alleviated systemic inflammation. The concurrent improvements in host metabolism and gut microbial composition prevented peripheral pro-inflammatory and oxidative stress signals from reaching the brain, thus inhibiting overactivation of hippocampal microglia and attenuating neuroinflammation. These effects preserved neuronal structure and function, ultimately enhancing learning, memory, and spatial cognition in AD model rats.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 9","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148812537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Manual tracking modulates representational momentum independently of visual feedback.","authors":"Seonghyeon Baek, Dong-Chan Huh, Kyeong-Bok Lee, Hee-Tae Cho, Ji-Hang Lee","doi":"10.1007/s00221-026-07381-z","DOIUrl":"10.1007/s00221-026-07381-z","url":null,"abstract":"<p><p>Representational momentum (RM) refers to the forward displacement of a moving object's remembered position in the direction of motion. Although RM in continuous motion is known to depend on oculomotor tracking, it remains unclear whether manual visuomotor tracking also modulates this bias and, if so, whether the effect reflects tracking-related predictive processing or compensation for proprioceptive uncertainty. In Experiment 1, participants (N = 21) observed a horizontally moving target through a semi-transparent mirror that spatially aligned the target with the tracking hand, without providing visual feedback of finger position. Eye behavior (smooth pursuit vs. fixation) and manual behavior (manual tracking vs. stationary) were independently manipulated in a 2 × 2 within-subject design. For the perceptual (memory-based) measure, RM was smallest during fixation and increased when either smooth pursuit or manual tracking was engaged, with the largest displacement observed in the eye-and-manual tracking condition. In contrast, the kinematic measures showed an effector-specific pattern: ocular overshoot increased with concurrent manual tracking, whereas manual overshoot increased when pursuit was withheld. In Experiment 2, online visual feedback of finger position was introduced during manual tracking. Despite improving tracking quality, visual feedback did not alter RM magnitude or overshoot, and Bayesian analyses provided weak-to-moderate evidence for the null. These findings suggest that RM under continuous tracking is more closely associated with tracking-related visuomotor processing than with compensatory extrapolation driven by effector uncertainty, a pattern consistent with-though not uniquely diagnostic of-an action-oriented predictive state estimation account.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 9","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148812491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of spatial attention on anatomical and external reference frames in tactile localization.","authors":"Moritaka Futamura, Han Gao, Koichi Hiraoka","doi":"10.1007/s00221-026-07385-9","DOIUrl":"10.1007/s00221-026-07385-9","url":null,"abstract":"<p><p>This study examined whether spatial attention contributes to anatomical and external reference frames for tactile localization during reaching movements. Nineteen right-handed participants reached toward a target in the left or right spatial hemifield with the left or right index finger. During the reach, a tactile stimulus was delivered to the reaching hand. After reaching, participants repositioned the stimulated hand to the location where the tactile stimulus had been delivered. They then verbally reported the perceived location of the tactile stimulus on the hand. The error in the anatomical reference frame for the left hand showed a more distal deviation than that for the right hand when participants reached into the left spatial hemifield, whereas no such difference was observed when they reached into the right spatial hemifield. This finding suggests that spatial attention in the left hemisphere reduces the proximal deviation of the perceived tactile stimulus location on the right hand within the anatomical reference frame. In the external reference frame, the error for the right hand showed a distal deviation relative to the left hand when they reached toward a target in the left spatial hemifield. Conversely, the error for the left hand showed a distal deviation relative to the right hand when they reached toward a target in the right spatial hemifield. These results indicate that conflict between the anatomical and external reference frames weakens the influence of spatial attention, resulting in a distal bias in perceived tactile location in external space.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 9","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148812524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proprioception is sufficient to coordinate simple bimanual lifts of unanticipated asymmetrically loaded objects.","authors":"Warren G Darling, Anna C Snyder, Lavena Mikhail","doi":"10.1007/s00221-026-07377-9","DOIUrl":"10.1007/s00221-026-07377-9","url":null,"abstract":"<p><p>The relative importance of proprioception and vision in control of bimanual lifting of a box with varied weight and weight distribution was studied to test whether availability of vision improved the lifting motion in terms of box orientation and temporal synchrony of lifting the two sides of the box. Twelve right-handed young adults performed a random sequence of bimanual lifts of a box with varied weight and weight distribution. When lifting a symmetrically loaded box there was excellent temporal synchrony of the motions of the left and right side and minimal deviation from a level box orientation. When lifting an asymmetrically loaded box there was delayed onset of lifting the heavier side of the box but temporal synchrony of right and left side motions subsequently improved such that left and right sides ended motion nearly synchronously. There was also greater deviation from a level box orientation during the lift that was corrected to nearly level at lift termination. Adaptations to changes in load symmetry from heavier load on one side to the other side occurred over 2-3 lifts to produce nearly synchronous lifts of the left and right sides with little deviation from a level box orientation. Allowing vision did not improve maintenance of box orientation or temporal synchronization of left and right side lifting motions. These results show that non-visual information is sufficient to control lifting a box to a level orientation when there is no prior knowledge of box weight or its distribution within the box.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"244 9","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503390/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148812091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}