Experimental Brain Research最新文献

{"title":"The effects of anticipation of standing surface translations on distal leg muscle excitations.","authors":"Virginie Ruest, Emily Eichenlaub, Jason R Franz","doi":"10.1007/s00221-025-07075-y","DOIUrl":"10.1007/s00221-025-07075-y","url":null,"abstract":"<p><p>This study aimed to investigate the interactions between anticipation and direction of surface translations applied during standing on distal leg muscle excitations measured via surface electromyography (EMG) in the context of resultant changes in center of mass (CoM) displacements. Twenty young adults experienced four combinations of surface translations (i.e., anticipated anterior, unanticipated anterior, anticipated posterior, unanticipated posterior) via a dual-belt instrumented treadmill. For each condition, a 200 ms, 6 m/s² anterior or posterior perturbation was delivered either unexpectedly or after a three-second verbal countdown. Each condition was repeated three times in a randomized order. We recorded surface EMG from the MG, SOL, and TA, and motion capture collected pelvis displacements as a surrogate for CoM. Data were analyzed across three time periods: pre-perturbation, early post-perturbation, and late post-perturbation. Direction-dependent EMG responses were as hypothesized, with TA iEMG increasing by 81% following anterior perturbations and MG and SOL iEMG increasing by 60% and 32% respectively following posterior perturbations. As hypothesized, anticipated balance challenges elicited greater proactive iEMG for all muscles. However, only unanticipated anterior perturbations elicited greater reactive TA iEMG than anticipated anterior perturbations. These proactive neuromechanical adjustments, particularly for anterior surface translations that would precipitate a backward fall, appeared protective and effective based on resultant patterns of CoM displacements. These data serve as a reference for understanding how aging and disease impact proactive and reactive postural control, especially for populations who may have difficulty with both the planning and execution of corrective neuromuscular adjustments.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"115"},"PeriodicalIF":1.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12000272/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143960794","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":"The sign of exploration during reward-based motor learning is not independent from trial to trial.","authors":"Katinka van der Kooij, Jeroen B J Smeets, Nina M van Mastrigt, Bernadette C M van Wijk","doi":"10.1007/s00221-025-07074-z","DOIUrl":"10.1007/s00221-025-07074-z","url":null,"abstract":"<p><p>Humans can learn various motor tasks based on binary reward feedback on whether a movement attempt was successful or not. Such 'reward-based motor learning' relies on exploiting successful motor commands and exploring different motor commands following failure. Most computational models of reward-based motor learning have formalized exploration as a random process, in which on each trial a random draw is taken from a normal distribution centred on zero. Whether human motor exploration is indeed random from trial to trial has not been tested yet. Here we tested in a force production task whether human motor exploration is random. To this end, we compared the proportion trial-to-trial force changes in the behavioural data that have the same sign to the proportion expected in random exploration. One group of participants practiced with an adaptive reward criterion, which keeps rewarded performance close to current performance, and the other group practiced with a fixed reward criterion in which current performance can be far from reward performance. In both groups, we found a proportion same-sign changes larger than predicted. In the Adaptive group, both the learning and proportion same-sign changes were consistent with model simulations for low values of random exploration, whereas in the Fixed group both the learning and proportion same-sign changes were inconsistent with model simulations based on random exploration. This suggests that some form of non-random motor exploration contributes to reward-based motor learning.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"117"},"PeriodicalIF":1.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12000264/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144005651","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":"Effect of force-rate on continuous kinesthetic force discrimination.","authors":"Ravi Prakash Meghwanshi, Amit Bhardwaj, Himanshu Kumar","doi":"10.1007/s00221-025-07080-1","DOIUrl":"10.1007/s00221-025-07080-1","url":null,"abstract":"<p><p>The effect of force-rate, i.e., rate of change of force stimuli, on continuous kinesthetic force perception has not been investigated and remains an open area for research. Previous studies do not account for the force-rate in the Weber fraction of kinesthetic force discrimination. However, this force-rate agnostic Weber fraction fails to explain continuous kinesthetic force discrimination fully. For example, if the signal changes very slowly, a participant may get accustomed to the change, and hence, a larger, just noticeable difference (JND) is expected. Conversely, for a fast-varying haptic force, a smaller JND is expected. In this work, we aim to explore the relationship between the Weber fraction and the force-rate. For this purpose, we designed an extensive psychophysical experiment where a participant is exposed to a linearly increasing kinesthetic force stimulus and is asked to react to the change. We utilize a machine learning-based approach to study the effect of force-rate on recorded haptic responses (perceived and non-perceived) of 10 participants while varying the force-rate stimuli in the range [1, 5] N/s. We determine the perceptual boundary between the perceived and non-perceived recorded responses using different classifiers based on linear and power functions of force-rate. The result indicates that the Weber fraction decreases significantly as the force-rate increases. The random forest classifier also confirms the significance of the utilized features in both perceptual boundaries. These findings may be useful in many virtual reality applications and telepresence and teleaction systems (TPTA).</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"118"},"PeriodicalIF":1.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143974070","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":"Retinal vessel density and cognitive function in healthy older adults.","authors":"Dieter F Kutz, Justus Obergassel, Melanie Mack, Robert Stojan, Boris Schmitz, Florian Alten, Claudia Voelcker-Rehage","doi":"10.1007/s00221-025-07076-x","DOIUrl":"10.1007/s00221-025-07076-x","url":null,"abstract":"<p><p>The eye is considered a gateway to the brain, as the retina is the only tissue of the central nervous system not protected by bones. This enables non-invasive imaging to provide exceptional insights into the brain. Based on the similarity of brain and retinal structure, it is being investigated whether changes in retinal blood flow could serve as a potential biomarker for cognitive decline. Optical coherence tomography angiography (OCTA) enables an examination of the microcirculation of the retina on the basis of retinal flow registration. Retinal blood flow has been associated with cognitive function and changes have been shown for Alzheimer's patients, whereas data for healthy older subjects are contradictory. The aim of this study was to correlate OCTA parameters with the individual performance in tests assessing the executive functions (EFs) inhibition, updating and shifting in a group of healthy older adults (range: 65-79) using structural equation modeling, with hematocrit serving as a mediator. A model was obtained for vessel density (VD) of the retinal superficial vascular complex and the EF parameters inhibition and updating. The model revealed that only the mediator hematocrit correlated with EF, whereas neither the direct path VD to EF nor the indirect path VD via hematocrit to EF were significantly correlated. Regression analysis with hematocrit yielded significant results for the variable updating. We conclude that higher levels of hematocrit shorten reaction time and the coefficient of variation increases correspondingly, indicating a positive effect of hematocrit on EF.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"114"},"PeriodicalIF":1.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12000121/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143995226","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":"Muscle length influences active joint position sense at the shoulder, but conditioning contractions do not.","authors":"David Alan Phillips, Bethany Burr","doi":"10.1007/s00221-025-07057-0","DOIUrl":"10.1007/s00221-025-07057-0","url":null,"abstract":"<p><p>Active shoulder joint position sense (JPS) is more accurate at higher angles of humerothoracic elevation. During active JPS testing, the extensor/antagonist muscles of the shoulder undergo repeated passive lengthening and do not contract to bring about shoulder extension. This may alter muscle spindle sensitivity at different angles of humeral elevation leading to angle related reduction in repositioning error. The purpose of this study is to examine active shoulder JPS when shoulder extensor muscles when were exposed to either a low-level contraction or full range of motion movement in an active angle reproduction JPS protocol. Fifteen participants completed the study. Participants completed the shoulder JPS protocol using three target angles (30°, 60°, and 90°) under three conditions: standard, range of motion exposure (fROM) between trials, and antagonist contraction (aCON) between trials. There was a significant interaction between conditions and angles (p = 0.002). JPS error decreased at higher elevations in the standard condition (p = 0.014) and aCON conditions (p = 0.035). The effect was absent in the fROM condition, where error across all target angles was consistent with the higher error at 30°. The outcomes suggest that change in the antagonist's muscle length and muscle spindle slackness are significant contributors to shoulder JPS.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"113"},"PeriodicalIF":1.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143987192","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":"Comparative effectiveness of exercise and art therapy programs in treating internet gaming disorder among adolescents: an 8-day intensive intervention study.","authors":"Taewoon Jung, Hyoungjin Park","doi":"10.1007/s00221-025-07068-x","DOIUrl":"10.1007/s00221-025-07068-x","url":null,"abstract":"<p><p>This study compared the effectiveness of exercise and art therapy programs for adolescents with Internet Gaming Disorder (IGD), investigating their impacts on gaming symptoms, psychological functioning, and behavioral problems. Forty-seven adolescents with IGD (aged 9-14 years) participated in either an 8-day exercise program (n = 23) or art therapy program (n = 24). Outcomes were assessed using the Korean Internet Addiction Scale (K-scale) and Korean Youth Self Report (K-YSR) at baseline, post-intervention, and one-month follow-up. Both interventions demonstrated significant effectiveness in reducing IGD symptoms (ηp² = 0.493) and improving psychological functioning. Withdrawal symptoms showed the strongest response (ηp² = 0.497), while improvements in anxiety/depression (ηp² = 0.562), aggressive behavior (ηp² = 0.516), and attention problems (ηp² = 0.514) were also substantial. No significant differences were found between the two programs (F(1, 45) = 1.870, p = 0.167, ηp² = 0.082). Although some regression occurred during the one-month follow-up, significant improvements were maintained across all domains compared to baseline (total score: MD = 9.98, p = 0.001), with particularly robust sustained improvements in aggressive behavior (MD = 4.778, p < 0.001) and anxious/depressed symptoms (MD = 4.140, p < 0.001). Both exercise and art therapy programs appear to be effective treatments for adolescent IGD, offering comparable benefits across multiple domains of functioning. The findings suggest that structured alternative activities, whether physical or creative, can effectively address both core IGD symptoms and associated psychological difficulties.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"112"},"PeriodicalIF":1.7,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143992377","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":"Reduced parietal to frontal functional connectivity for dynamic balance in late middle-to-older adults.","authors":"Mahdis Dadfar, Komal K Kukkar, Pranav J Parikh","doi":"10.1007/s00221-025-07070-3","DOIUrl":"10.1007/s00221-025-07070-3","url":null,"abstract":"<p><p>In this study, we investigated the changes in functional connectivity between cortical regions for balance control during a challenging balance task with advancing age. Fourteen young and fourteen late middle-to-older adults performed a challenging balance task that manipulated somatosensory information while their brain activity was recorded using electroencephalography. Both groups showed common activation regions within the posterior cingulate cortex (PCC) and premotor cortex (PMC) during the balance task. The late middle-to-older group showed significantly weaker PCC to PMC functional connectivity than the young group. This finding indicated poor sensorimotor processes during altered reliance on somatosensory inputs for balance maintenance. The regularity of foot center of pressure fluctuations measured using sample entropy was greater in the late middle-to-older group than the young group, suggesting a shift from automatic control to cognitive control of balance. Weaker PCC to PMC connectivity in late middle-to-older adults was associated with greater regularity of foot center of pressure fluctuations. In late middle-to-older adults, an additional cortical region was activated, the prefrontal cortex, during the balance task. Our findings suggest a shift from the parietal-to-frontal sensorimotor network to the prefrontal network for dynamic control of balance with advancing age.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"111"},"PeriodicalIF":1.7,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12123830/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143981789","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":"Effect of DC-GVS on resting functional EEG networks in healthy people.","authors":"Yuehua Geng, Jianzhi Ma, Wenlu Xue, Xiaolin Zhou, Guizhi Xu, Xiang Zhai","doi":"10.1007/s00221-025-07035-6","DOIUrl":"10.1007/s00221-025-07035-6","url":null,"abstract":"<p><strong>Objective: </strong>To establish a resting state functional network based on electroencephalogram (EEG) signals and explore the effects of different intensities of direct current (DC) Galvanic Vestibular Stimulation (GVS) on healthy people. Furthermore, from the perspective of EEG connectivity and topological structure, the mechanism of DC GVS's influence on the connectivity of vestibular related nerve functions was studied.</p><p><strong>Methods: </strong>the subjets were given DC GVS stimulations which indensities are one time pain threshold, two times pain threshold and four times pain threshold. Sham stimulation was applied to be the control group. EEG signals after stimulation were collected in every group. The wPLI method was used to construct the correlation matrix, and though setting the threshold value to construct the binary matrix. The brain network topology parameters that solved by binary matrix were analyzed to explore the impact of GVS with different intensities. Results: DC GVS stimulation of one-time threshold, two-times threshold and four-times threshold can change the brain network connection and the topological properties of the brain network. And the effect of two-times threshold GVS stimulation is the most significant.</p><p><strong>Conclusion: </strong>GVS with different intensities on healthy people could improve the efficiency of information transmission in different brain regions, increase the speed of information transmission, and enhance the strength of functional connectivity. It provides a theoretical reference for the neural effects of GVS from the perspective of brain functional network.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"109"},"PeriodicalIF":1.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143810830","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":"Oculomotor, vestibular, reaction time, and cognitive (OVRT-C) responses in 7- to 17-year-old children.","authors":"Alex Kiderman, Jennifer Coto, Laura C Gibson, Robin C Ashmore, Alexandr Braverman, Erin Williams, Angela M Flamm Finamore, Valerie Yunis, Michael E Hoffer","doi":"10.1007/s00221-025-07005-y","DOIUrl":"10.1007/s00221-025-07005-y","url":null,"abstract":"<p><p>Several aspects of oculomotor, vestibular, reaction time, and cognitive (OVRT-C) abilities improve throughout childhood at varying rates and become adult-like at different ages. However, developmental testing of these abilities often focuses on limited age ranges and does not elucidate clear developmental trajectories. The present study utilized high-resolution eye-tracking to evaluate 40 children aged 7-17 years on a comprehensive battery of OVRT-C tests to better understand how and when these abilities develop across childhood. As expected, mean responses on OVRT-C tests showed consistent improvement as subject age increased. We report a high prevalence of saccadic intrusions during smooth pursuit in children and adolescents, more self-paced saccades in older children, decreased auditory and visual RT with age, and fewer errors on the anti-saccade test in older children. We also used the Akaike information criterion (AIC) and Bayesian information criterion (BIC) modelling to determine whether a two- or three age group division would be most appropriate for each OVRT-C test. For all key OVRT-C metrics, our data support a separation of children into two age groups as opposed to three. While the age group divide varied by OVRT-C test, these data suggest these abilities mature at differing rates, and optimal separations into two age groups rather than three may reflect a slowing of rapid development as OVRT-C performance becomes more adult-like.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"110"},"PeriodicalIF":1.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11982098/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143810788","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":"Construction of a computational model of individual progression of motion sickness symptoms based on subjective vertical conflict theory.","authors":"Shota Inoue, Van Trong Dang, Hailong Liu, Takahiro Wada","doi":"10.1007/s00221-025-07052-5","DOIUrl":"10.1007/s00221-025-07052-5","url":null,"abstract":"<p><p>Computational models predicting motion sickness have advanced, particularly those based on subjective vertical conflict (SVC) theory. While SVC-based models primarily predict motion sickness incidence (MSI), which is defined as the percentage of people who would vomit under a given motion, models predicting milder individual symptoms, which are crucial for daily applications, are still required. Recently, computational models predicting vestibular motion-sickness progression using the SVC theory have been developed by changing the output of a 6DOF-SVC model from MSI to the Misery Scale (MISC), a subjective measure of symptom progression. In practical applications, the ability to predict MISC for unseen motions is crucial. The present study conceived a method for predicting MISC beyond a certain point in the future by identifying parameters from data collected up to that point. Therefore, this study investigates the effect of the number of data points used for parameter identification on the future prediction accuracy. Observed MISC responses from participants exposed to linear lateral motion in darkness were used for model validation. The results indicated that prediction accuracy increased as more data points were included. On average, using more than 5-10 min of data significantly increased the accuracy compared to a model using averaged parameter sets across participants, although the tendency significantly differed based on an individual's MISC history. A trial considering individual MISC histories, in which data points were defined when the observed MISC first reached certain levels, showed a general trend of improved accuracy when data up to MISC Level 3 was used. The findings of this study demonstrate that motion sickness symptom progression can be predicted with reduced error by incorporating individual symptom histories, thereby providing a foundation for the development of personalized motion sickness prediction models applicable to broader applications.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 5","pages":"108"},"PeriodicalIF":1.7,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11972198/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143788255","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}