Experimental Brain Research最新文献

{"title":"Error compensation in a redundant system during 'failure' of individual motor elements.","authors":"Narae Shin, Yu Mei, Xiaobo Tan, Vaibhav Srivastava, Rajiv Ranganathan","doi":"10.1007/s00221-024-06987-5","DOIUrl":"10.1007/s00221-024-06987-5","url":null,"abstract":"<p><p>A characteristic feature of redundancy in the motor system is the ability to compensate for the failure of individual motor elements without affecting task performance. In this study, we examined the pattern and variability in error compensation between motor elements during a virtual task. Participants performed a redundant cursor control task with finger movements. In some conditions, we induced 'failure' by using a haptic glove to apply forces to constrain the motion of one of four fingers (index, middle, ring, or little). Our results showed that (i) other fingers increased their range of motion to compensate for the failure of a specific finger, with most of this compensation coming from non-adjacent fingers, and (ii) there was greater trial-to-trial variation in how the task was achieved as indexed by the higher null space variability when the middle and ring fingers were constrained. These results highlight the key role of the interdependence between motor elements in determining error compensation patterns and the variability in coordination patterns.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 2","pages":"46"},"PeriodicalIF":1.7,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143001667","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":"Integrating vestibular and visual cues for verticality perception.","authors":"Catho Schoenmaekers, Floris L Wuyts, Elisa R Ferre","doi":"10.1007/s00221-024-06992-8","DOIUrl":"10.1007/s00221-024-06992-8","url":null,"abstract":"<p><p>Verticality is the perception of what's upright relative to gravity. The vestibular system provides information about the head's orientation relative to gravity, while visual cues influence the perception of external objects' alignment with the vertical. According to Bayesian integration, the perception of verticality depends on the relative reliability of visual and vestibular cues. Ambiguities in vestibular signals are resolved through visual information, with the brain integrating these cues alongside prior knowledge of the upright orientation. While it is established that both vestibular and visual cues contribute to verticality perception, the precise mechanisms underlying this integration remain unclear. Here we investigated how the human brain combines vestibular and visual cues to perceive verticality based on their reliability. We assessed verticality perception using a signal detection theory based visual verticality detection task. Participants were shown lines that were either vertical or tilted and asked to judge their orientation. To manipulate cue reliability, we used optokinetic stimulation for visual cues, galvanic vestibular stimulation for vestibular cues, and a combined visual-vestibular condition by simultaneously delivering optokinetic and galvanic vestibular stimulation. Sham stimulations were administered to control for non-specific effects. Our findings demonstrate that reductions in the reliability of visual and vestibular cues impair sensitivity to verticality, with visual cues exerting a more pronounced influence. Importantly, no changes in response bias were observed. The observed pattern aligns with a model in which the relative contributions of visual and vestibular inputs are determined by linear weightings and their combined summation.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 2","pages":"49"},"PeriodicalIF":1.7,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143002442","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":"Effects of lifestyle activity level on anticipatory locomotor adjustments for pedestrian circumvention: an exploratory study.","authors":"Joris Boulo, Margaux Simon, Bradford J McFadyen, Andreanne K Blanchette","doi":"10.1007/s00221-024-06980-y","DOIUrl":"10.1007/s00221-024-06980-y","url":null,"abstract":"<p><p>Navigating public environments requires adjustments to one's walking patterns to avoid stationary and moving obstacles. It is known that physical inactivity induces alterations in motor capacities, but the impact of inactivity on anticipatory locomotor adjustments (ALA) has not been studied. The purpose of the present exploratory study was to compare ALAs and related muscle co-contraction during a pedestrian circumvention task between active (AA) and inactive young adults (IA). Fourteen AA and fourteen IA were placed in a virtual environment simulating a public park. Participants circumvented virtual pedestrians walking towards them. Walking speed, onset of deviation, clearance, foot placement strategies and muscle co-contraction were analysed on a total of 26 participants (13 in each group; 2 excluded due to technical issues). IA exhibited slower walking speeds compared to the AA during circumvention condition but not during unobstructed walking condition. The distance at the onset of trajectory deviation was larger for IA. Both groups increased co-contraction for pedestrian circumvention at the ankle and left hip and IA displayed greater ankle co-contraction overall. No significant group differences were observed in minimum clearance. This study suggests that an inactive lifestyle influences ALAs by inducing a cautious behavior during pedestrian circumvention.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 2","pages":"48"},"PeriodicalIF":1.7,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143002923","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":"In a visual inverted pendulum balancing task avoiding impending falls gets harder as we age.","authors":"Hannah E Park, Avijit Bakshi, James R Lackner, Paul DiZio","doi":"10.1007/s00221-025-06997-x","DOIUrl":"10.1007/s00221-025-06997-x","url":null,"abstract":"<p><p>Younger adults (YA) and older adults (OA) used a joystick to stabilize an unstable visual inverted pendulum (VIP) with a fundamental frequency (.27 Hz) of half that of bipedal human sway. Their task was to keep the VIP upright and to avoid ± 60° \"fall\" boundaries. Both age groups were tested with joystick gains and delays simulating age-related muscle strength and reflex slowing, respectively. In previous VIP and analogous self-balancing tasks, we observed a mixture of discrete corrective commands toward the balance point and destabilizing commands toward an impending fall. We hypothesized that (1) OA would fall more than YA, (2) traditional whole-trial stability and variability measures would differ across age groups and VIP conditions, and (3) different dynamics of corrective and destabilizing commands would discriminate falling from recovery. Results: (i) Traditional whole-trial performance metrics of fall incidence and the variance of position and velocity were worse in OA than YA and worse with longer delays and excessive joystick gains; (ii) OA made fewer corrective and more destabilizing commands than YA only when falling was imminent; (iii) when falls were imminent, a logistic model fit the percentage of inactive, corrective, and destabilizing commands as a function of time left to fall; and (iv) OA were like YA in switching between inaction and action, but exhibited less frequent and less prompt corrective commands than destabilizing commands relative to YA. We discuss whether such a decision-like process may also operate in a bipedal stance.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 2","pages":"44"},"PeriodicalIF":1.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11735510/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143002051","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":"Synchronization of auditory-hand tapping coupling: the effect of aging.","authors":"Benedetta Heimler, Miriam Sofia, Noam Galor, Oran Ben-Gal, Yotam Bahat, Gabi Zeilig, Meir Plotnik","doi":"10.1007/s00221-024-06993-7","DOIUrl":"10.1007/s00221-024-06993-7","url":null,"abstract":"<p><p>Hand(s)-tapping tasks have been extensively studied in order to characterize the features of sensorimotor synchronization (SMS). These tasks frequently require participants to synchronize their tapping pace to an external, metronome-like sound. The impact of ageing on SMS abilities remains mainly unexplored. Thus, we conducted a series of hand tapping tasks on 15 young adults (YA) and 15 older adults (OA). The tasks included tapping with the dominant hand only (D), with the non-dominant hand only (ND), with both hands simultaneously (SIM), and alternating between the hands (ALT). Participants in each task performed a synchronization-continuation task, in which they had to tap for one minute according to an external sound set at their spontaneous motor tempo (separately identified), and then, after the sound stopped, continue tapping at the same tempo for another minute. Results indicated a set of preserved and degraded tapping behaviors in OA compared to YA. The ALT task produced the most deteriorated tapping performance, followed by the ND task; the other two tasks revealed no difference between the groups. These findings shed more light on how SMS declines across the lifespan and provide some preliminary but important information that may guide rehabilitation and diagnostic procedures.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 1","pages":"43"},"PeriodicalIF":1.7,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142982955","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":"The roles of vision and proprioception in spatial tuning of sensory attenuation.","authors":"Clara Fritz, Manuel Bayer, Eckart Zimmermann","doi":"10.1007/s00221-024-06982-w","DOIUrl":"10.1007/s00221-024-06982-w","url":null,"abstract":"<p><p>When we touch ourselves, the pressure appears weaker compared to when someone else touches us, an effect known as sensory attenuation. Sensory attenuation is spatially tuned and does only occur if the positions of the touching and the touched body-party spatially coincide. Here, we ask about the contribution of visual or proprioceptive signals to determine self-touch. By using a 3D arm model in a virtual reality environment, we dissociated the visual from the proprioceptive arm signal. When a virtual arm was visible indicating self-touch, we found that sensory attenuation generalized across different locations. When no virtual arm was visible, we found sensory attenuation to be strongest when subjects pointed to the position where they felt their arm to be located. We conclude that the spatial tuning of tactile attenuation depends on which signal determines the occurrence of self-touch. When observers can see their hand, the visual signal dominates the proprioceptive determining self-touch in a single visual snapshot. When only the proprioceptive signal is available, the positions of the touching and the touched body-part must be separately estimated and subsequently compared if they overlap in anatomical space.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 1","pages":"42"},"PeriodicalIF":1.7,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11724775/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142964367","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 role of muscle synergies and task constraints on upper limb motor impairment after stroke.","authors":"Pablo Ortega-Auriol, Winston D Byblow, April Xiaoge Ren, Thor Besier, Angus J C McMorland","doi":"10.1007/s00221-024-06953-1","DOIUrl":"10.1007/s00221-024-06953-1","url":null,"abstract":"<p><p>This study explores the role of task constraints over muscle synergies expression in the context of upper limb motor impairment after stroke. We recruited nine chronic stroke survivors with upper limb impairments and fifteen healthy controls, who performed a series of tasks designed to evoke muscle synergies through various spatial explorations. These tasks included an isometric force task, a dynamic reaching task, the clinical Fugl-Meyer (FM) assessment, and a pinch task. Electromyographic data from 16 upper limb muscles were collected during each task, alongside intermuscular coherence (IMC) measurements during the pinch task to assess neuromuscular connectivity. The findings confirm that motor impairment is inversely related to the diversity of muscle synergies, with fewer synergies and more stereotypical synergy structures observed post-stroke. The study further reveals that the nature of motor tasks significantly affects the number of identifiable muscle synergies, with less constrained tasks revealing a broader array of synergies. These findings highlight the importance of carefully selecting motor tasks in the context of clinical research and assessments to understand a patient's motor impairment, thus aiding in developing tailored rehabilitation strategies.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 1","pages":"40"},"PeriodicalIF":1.7,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11706858/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142947057","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":"Acute hypoalgesic and neurophysiological responses to lower-limb ischaemic preconditioning.","authors":"Ryan Norbury, Ian Grant, Alex Woodhead, Stephen D Patterson","doi":"10.1007/s00221-024-06985-7","DOIUrl":"10.1007/s00221-024-06985-7","url":null,"abstract":"<p><p>The aim of this study was to assess if ischaemic preconditioning (IPC) can reduce pain perception and enhance corticospinal excitability during voluntary contractions. In a randomised, within-subject design, healthy participants took part in three experimental visits after a familiarisation session. Measures of pressure pain threshold (PPT), maximum voluntary isometric force, voluntary activation, resting twitch force, corticospinal excitability and corticospinal inhibition were performed before and ≥10 min after either, unilateral IPC on the right leg (3 × 5 min); a sham protocol (3 × 1 min); or a control (no occlusion). Pain perception was then assessed in response to a hypertonic saline injection into the vastus lateralis muscle. In the right (occluded) leg, PPT was 10% greater after IPC compared to sham (P = 0.004). PPTs were also 9.5% greater in the contralateral leg for IPC compared to sham (P = 0.031). Maximum voluntary force, voluntary activation and resting twitch force were not different between conditions (all P ≥ 0.133). Measures of corticospinal excitability and inhibition also revealed no significant differences between conditions (all P ≥ 0.240). Hypertonic saline evoked pain revealed no difference in reported intensity or duration between conditions (P ≥ 0.082). IPC can reduce pain sensitivity in local and remote areas but does not subsequently impact neurophysiological measures of excitability or inhibition.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 1","pages":"41"},"PeriodicalIF":1.7,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142947055","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":"The link between eye movements and cognitive function in mild to moderate Alzheimer's disease.","authors":"Xiao-Ting Ma, Lin-Lin Yao, Shan-Wen Liu, Xiao-Fen Weng, Run-Ying Bao, Yi-Fan Yang, Yi-Feng Li, Yan-Yun Sun, Dan Xu, Zhen-Yu Jia, Hua Hu","doi":"10.1007/s00221-024-06957-x","DOIUrl":"10.1007/s00221-024-06957-x","url":null,"abstract":"<p><p>This study investigated the relationship between eye movement parameters and cognitive function in patients with mild to moderate Alzheimer's disease (AD). A total of 80 patients with AD (mild and moderate) and 34 normal controls (NC) participated. Neuropsychological assessments were conducted using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA), while eye movements were recorded using eye-tracking technology. Comparisons of neuropsychological scores and eye movement parameters were made across the groups, and partial correlation analysis was performed to examine associations between eye movement metrics and specific cognitive domains. No significant differences were found among the groups in pursuit and fixation tasks. However, in pro-saccade tasks, patients in the moderate AD group exhibited significantly lower accuracy and longer latency compared to those in the mild AD and NC groups. Similarly, in anti-saccade tasks, the moderate AD group showed significantly lower accuracy and error correction rates compared to the other groups. Partial correlation analysis revealed that overall cognitive function was positively associated with the accuracy of pro-saccade and anti-saccade tasks, as well as the error correction rate of anti-saccade tasks, but negatively associated with pro-saccade latency. Further, orientation was negatively correlated with saccade latency and positively correlated with saccade accuracy, while visuospatial skills were positively associated with the accuracy of both saccade and anti-saccade tasks. A positive correlation was also observed between word fluency and both saccade accuracy and error correction rate. These findings indicate that eye movement parameters, particularly those related to saccade and anti-saccade tasks, are associated with various cognitive domains in mild to moderate AD patients. Eye-tracking technology may provide a convenient and non-invasive tool for assessing cognitive function and aiding in the diagnosis and evaluation of AD.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 1","pages":"39"},"PeriodicalIF":1.7,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142926972","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":"Comparing auditory and visual aspects of multisensory working memory using bimodally matched feature patterns.","authors":"Işıl Uluç, Tori Turpin, Parker Kotlarz, Kaisu Lankinen, Fahimeh Mamashli, Jyrki Ahveninen","doi":"10.1007/s00221-024-06991-9","DOIUrl":"10.1007/s00221-024-06991-9","url":null,"abstract":"<p><p>Working memory (WM) reflects the transient maintenance of information in the absence of external input, which can be attained via multiple senses separately or simultaneously. Pertaining to WM, the prevailing literature suggests the dominance of vision over other sensory systems. However, this imbalance may be stemming from challenges in finding comparable stimuli across modalities. Here, we addressed this problem by using a balanced multisensory retro-cue WM design, which employed combinations of auditory (ripple sounds) and visuospatial (Gabor patches) patterns, adjusted relative to each participant's discrimination ability. In three separate experiments, the participant was asked to determine whether the (retro-cued) auditory and/or visual items maintained in WM matched or mismatched the subsequent probe stimulus. In Experiment 1, all stimuli were audiovisual, and the probes were either fully mismatching, only partially mismatching, or fully matching the memorized item. Experiment 2 was otherwise the same as Experiment 1, but the probes were unimodal. In Experiment 3, the participant was cued to maintain only the auditory or visual aspect of an audiovisual item pair. In Experiments 1 and 3, the participant's matching performance was significantly more accurate for the auditory than visual attributes of probes. When the perceptual and task demands are bimodally equated, auditory attributes can be matched to multisensory items in WM at least as accurately as, if not more precisely than, their visual counterparts.</p>","PeriodicalId":12268,"journal":{"name":"Experimental Brain Research","volume":"243 1","pages":"38"},"PeriodicalIF":1.7,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11848833/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142909465","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}