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Purpose: To determine the effects of repeated Brazilian jiujitsu (BJJ) matches on neuromuscular fatigue in forearm-flexor and knee-extensor muscles. Methods: Twelve BJJ athletes (8 men and 4 women) performed a simulated BJJ tournament composed of four 8-minute matches interspersed by 16-minute intervals. Neuromuscular fatigue was assessed via prematch to postmatch(es) reductions in maximal voluntary isometric contraction (MVIC), voluntary activation, and potentiated twitch force (Ptwpot) in the forearm-flexor and knee-extensor muscles. Results: The MVIC of the knee extensors and forearm flexors reduced from prematch 1 to postmatch 2 and remained suppressed until postmatch 4 (P <.034). The voluntary activation of the knee extensors declined only after match 4, whereas the voluntary activation of the forearm flexors did not change throughout the matches (P =.102). Ptwpot of knee extensors decreased from prematch 1 to postmatch 1 (P <.001) and remained reduced until postmatch 4 (P <.001). Ptwpot of the forearm flexors reduced after every match (P <.010), with complete recovery occurring only before the second match (P =.99). The magnitude of the prematch-to-postmatch reduction in Ptwpot was lower in knee extensors than in forearm flexors (P =.044). Conclusions: Repeated BJJ matches induced neuromuscular fatigue, mainly due to impairments in muscle contractile function (ie, peripheral fatigue). The time between BJJ matches seems to be insufficient to allow complete recovery of neuromuscular function, which may influence performance during subsequent matches. [ABSTRACT FROM AUTHOR]

Context: The Y-Balance Test Lower Quarter (YBT-LQ) is a widely utilized tool for evaluating dynamic postural control, requiring a combination of mobility and strength. This study aimed to investigate the combined relationship between isometric thigh muscle strength and joint kinematics on YBT-LQ performance. Design: Cross-sectional laboratory study. Methods: Isometric quadriceps and hamstrings strength were measured before the YBT-LQ in 39 healthy participants (27 females and 12 males). The test was performed under 3-dimensional markerless motion capture, where joint kinematics were extracted from the maximum reach position from each direction. Three multivariable linear regression models were then used to determine the strongest combination of predictors for YBT-LQ performance. Results: Greater hamstrings strength and increased knee flexion, ankle dorsiflexion, and trunk ipsilateral-flexion joint angles explained 56.8% (P <.001) of the variance in anterior reach. Hip flexion, knee flexion, and ankle dorsiflexion angles were the strongest predictors for posteromedial reach distance, explaining 73.0% of the variance (P <.001). Last, 43.3% (P <.001) of the variance in posterolateral reach distance was predicted by hamstring strength and knee-flexion angle. Conclusions: These results emphasize the importance of hamstring strength in YBT-LQ performance across different reach directions. Additionally, the kinematics illustrate a potential movement strategy for maximizing reach distance on the YBT-LQ in healthy individuals. Clinicians can utilize this information to guide interventions aimed at improving dynamic postural control, particularly by focusing on increasing hamstring strength and testing for impairments in specific movement patterns. [ABSTRACT FROM AUTHOR]

Purpose: To study whether, during typical-level running, non-rear-foot strikers (non-RFS) or rear-foot strikers (RFS) presented a similar or different extent of neuromuscular fatigue after a prolonged graded run. Methods: Sixteen experienced male trail runners (8 non-RFS and 8 RFS) performed a 2.5-hour treadmill graded running exercise. Before and after exercise, neuromuscular tests were performed to assess neuromuscular fatigue of the plantar flexors. Biomechanical gait parameters were acquired with an instrumented treadmill, and electromyographic activity of the lower-limb muscles was collected as an index of muscle activation. Results: There were no significant time × foot strike interactions for neuromuscular (all P ≥.742), muscle activation (all P ≥.157), or biomechanical (all P ≥.096) variables. Conclusions: A dominant level running foot-strike pattern did not directly affect the extent of neuromuscular fatigue during a prolonged graded run. This suggests that no ideal running foot-strike pattern exists to minimize neuromuscular fatigue during prolonged-duration races wherein cumulative uphill and downhill segments are high, such as in trail running. [ABSTRACT FROM AUTHOR]

The literature describing the effects of mental fatigue (MF) has grown tremendously. This is accompanied by identification of a host of performance-determining parameters affected by MF. MF results from prolonged cognitive effort and predominantly affects physical, technical, tactical, and perceptual–cognitive dimensions of sport, while physiological parameters (eg, heart rate, lactate) and physical aspects of maximal and supramaximal efforts are predominantly unaffected. The aim of this paper was to provide an overview of the parameters described in the literature as influenced by MF. By identifying the different parameters, we not only see how they affect the performance of athletes but also raise concerns about the potentially increased injury risk due to MF. Preliminary evidence suggests that subsequent disturbances in balance, motor skills, and decision-making processes could potentially increase the vulnerability to injury. An abundance of lab-based studies looked into the effects of MF on performance; however, many questions remain about the mechanisms of origin and neurophysiological causes of MF, and only small steps have been taken to translate this knowledge into practice. Thus, there is a need for more research into the underlying mechanisms of MF and the role of the brain, as well as more applied research with a high ecological validity that also takes into account the potential increased risk of injury due to MF. [ABSTRACT FROM AUTHOR]

Purpose: To compare the training characteristics of an elite team pursuit cycling squad in the 3-month preparation phases prior to 2 successive world-record (WR) performances. Methods: Training data of 5 male track endurance cyclists (mean [SD]; age 23.4 [3.46] y; body mass 80.2 [2.74] kg; 4.5 [0.17] W·kg−1 at LT2; maximal aerobic power 6.2 [0.27] W·kg−1; maximal oxygen uptake 65.9 [2.89] mL·kg−1·min−1) were analyzed with weekly total training volume by training type and heart rate, power output, and torque intensity distributions calculated with reference to the respective WRs' performance requirements. Results: Athletes completed 805 (82.81) and 725 (68.40) min·wk–1 of training, respectively, in each season. In the second season, there was a 32% increase in total track volume, although track sessions were shorter (ie, greater frequency) in the second season. A pyramidal intensity distribution was consistent across both seasons, with 81% of training, on average, performed below LT1 power output each week, whereas 6% of training was performed above LT2. Athletes accumulated greater volume above WR team pursuit lead power (2.4% vs 0.9%) and torque (6.2% vs 3.2%) in 2019. In one athlete, mean single-leg-press peak rate of force development was 71% and 46% higher at mid- and late-phases, respectively, during the preparation period. Conclusions: These findings provide novel insights into the common and contrasting methods contributing to successive WR team pursuit performances. Greater accumulation of volume above race-specific power and torque (eg, team pursuit lead), as well as improved neuromuscular force-generating capacities, may be worthy of investigation for implementation in training programs. [ABSTRACT FROM AUTHOR]

Purpose: To compare the effects of 6-week barbell weighted-jump-squat (WJS) training with and without eccentric load reduction on explosive performance. Methods: Twenty well-trained male athletes were randomly assigned to either an experimental group (n = 10) or a control group (n = 10). Participants completed 12 WJS training sessions (6 sets of 5 repetitions of barbell back squat at 30% of 1-repetition maximum [1RM]) twice a week over a 6-week period. While the control group used 0% eccentric loading (ie, traditional WJS), the experimental group utilized a 50% eccentric loading reduction with a mechanical braking unit (ie, eccentric load set at 15% of 1RM). Performance assessments, including countermovement jump, 20-m sprint, standing long jump, and 1RM barbell back squat, were conducted both before (pretests) and after (posttests) the intervention. Results: Both the experimental group and the control group demonstrated a significant increase in countermovement-jump height (+6.4% [4.0%] vs +4.9% [5.7%]; P <.001) and peak power output (+2.3% [2.7%] vs +1.9% [5.1%]; P =.017), faster 20-m sprint times (+9.4% [4.8%] vs +9.2% [5.5%]; P <.001), longer standing long jump (+3.1% [2.5%] vs +3.0% [3.3%]; P <.001), and higher 1RM back squat (+6.4% [4.0%] vs +4.9% [5.7%]; P <.001) from pretests to posttests. However, there was no significant condition × time interaction for any variable (all P ≥.294). Conclusions: Both WJS training methods, with and without load reduction in the eccentric phase, effectively enhance explosive performance. Nevertheless, athletes in later stages of injury rehabilitation or intense training may find reducing eccentric load a more tolerable strategy for achieving similar performance gains compared with traditional isoinertial loading. [ABSTRACT FROM AUTHOR]

Purpose: This study explored the effects of 4 bench-press (BP) training programs with different velocity-loss (VL) thresholds (0%, 15%, 25%, and 50%) on strength gains and neuromuscular adaptations. Methods: Forty-six resistance-trained men (22.8 [4.4] y) were randomly assigned into 4 groups that differed in the VL allowed within the set: 0% (VL0), 15% (VL15), 25% (VL25), and 50% (VL50). Training loads (40%–55% 1-repetition maximum), frequency (2 sessions/wk), number of sets (3), and interset recovery (4 min) were identical for all groups. Participants completed the following tests before and after an 8-week (16-session) BP training program: (1) maximal isometric test, (2) progressive loading test, and (3) fatigue test in the BP exercise. During all tests, triceps brachii muscle electromyography was assessed. Results: After completing the resistance-training program, no significant group × time interactions were noticed for isometric and dynamic BP strength variables. The dose–response relationship exhibited an inverted U-shaped relationship pattern, with VL25 showing the greatest effect sizes for almost all strength variables analyzed. The total number of repetitions performed during the training program increased as the VL magnitude increased. Conclusions: The group that trained with high VL threshold (50%), which performed a total of 876 repetitions, did not experience additional strength gains compared with those experienced by the 0%, 15%, and 25% of VL groups, which performed significantly fewer repetitions (48, 357, and 547, respectively). These findings suggest that when light loads (40%–55% 1-repetition maximum) are used, low and moderate VL thresholds (0%–25%) provide a higher training efficiency. [ABSTRACT FROM AUTHOR]

The mechanical efficiency of human locomotion has been studied extensively. The mechanical efficiency of the whole body occasionally exceeds muscle efficiency during bouncing type gaits. It is thought to occur due to elasticity and stiffness of the tendinomuscular system and neuromuscular functions, especially stretch reflexes. In addition, the lower limb joint kinetics affect mechanical efficiency. We investigated the impact of varying external work on mechanical efficiency and lower limb kinetics during repeated sledge jumping. Fifteen male runners performed sledge jumping for 4 minutes at 3 different sledge inclinations. Lower limb kinematics, ground reaction forces, and expired gases were analyzed. Mechanical efficiency did not differ according to sledge inclination. Mechanical efficiency correlated positively with the positive mechanical work of the knee and hip joints and the negative contribution of the hip joints. Conversely, it correlated negatively with both the positive and negative contributions of the ankle joint. This may be attributable to the greater workload in this study versus previous studies. To achieve greater external work, producing more mechanical energy at the proximal joint and transferring it to the distal joint could be an effective strategy for improving mechanical efficiency because of the greater force-generating capability of distal joint muscles. [ABSTRACT FROM AUTHOR]

This study aimed to determine whether caffeine gum influenced perceptual-cognitive and physical performance during the extra-time period of simulated soccer match-play. Semiprofessional male soccer players (n = 12, age: 22 ± 3 years, stature: 1.78 ± 0.06 m, mass: 75 ± 9 kg) performed 120-min soccer-specific exercise on two occasions. In a triple-blind, randomized, crossover design, players chewed caffeinated (200 mg; caffeine) or control (0 mg; placebo) gum for 5 min following 90 min of soccer-specific exercise. Perceptual-cognitive skills (i.e., passing accuracy, reaction time, composure, and adaptability) were assessed using a soccer-specific virtual reality simulator, collected pre- and posttrial. Neuromuscular performance (reactive-strength index, vertical jump height, absolute and relative peak power output, and negative vertical displacement) and sprint performance (15 and 30 m) were measured at pretrial, half-time, 90 min, and posttrial. Caffeine gum attenuated declines in reaction time (pre: 90.8 ± 0.8 AU to post: 90.7 ± 0.8 AU) by a further 4.2% than placebo (pre: 92.1 ± 0.8 AU to post: 88.2 ± 0.8 AU; p <.01). Caffeine gum reduced composure by 4.7% (pre: 69.1 ± 0.8 AU to post: 65.9 ± 0.8 AU) versus placebo (pre: 68.8 ± 0.8 AU to post: 68.3 ± 0.8 AU; p <.01). Caffeine gum did not influence any other variables (p >.05). Where caffeine gum is consumed by players prior to extra-time, reaction time increases but composure may be compromised, and neuromuscular and sprint performance remain unchanged. Future work should assess caffeine gum mixes with substances like L-theanine that promote a relaxed state under stressful conditions. [ABSTRACT FROM AUTHOR]

Purpose: This cohort study aimed to investigate the relationship between subjective (wellness and internal training load [ITL]) and objective (neuromuscular fatigue) monitoring markers and performance aspects (reception quality [RQ] and attack efficiency [AE]) in professional female volleyball players. Methods: The study was conducted over an 8-week period during the final mesocycle of the competitive phase. A total of 24 training sessions and 10 matches were included in the analysis. Subjective measures of wellness and ITL were assessed, and neuromuscular fatigue was evaluated using countermovement-jump (CMJ) height. RQ and AE were determined based on game statistics. Results: The study found a positive relationship between wellness and RQ, particularly affecting outside hitters and liberos. ITL showed a positive association with AE, primarily impacting outside hitters, opposite hitters, and middle blockers. Additionally, ITL demonstrated a negative correlation with RQ, mainly affecting outside hitters and liberos. CMJ performance was associated with AE, where a decrease in CMJ height was linked to reduced AE. Conclusions: The findings highlight the importance of considering players' wellness scores in training and match strategies for different positions. Careful management of training loads, considering both physical and technical demands, is crucial for optimizing performance outcomes. Monitoring neuromuscular fatigue, as indicated by CMJ performance, is particularly relevant for outside hitters, opposite hitters, and middle blockers involved in attack actions. Coaches, trainers, and sports practitioners can use these insights to develop position-specific training protocols and implement effective strategies for maintaining or improving performance metrics under various stressors. [ABSTRACT FROM AUTHOR]

Purpose: To examine the sex differences in performance and perceived fatigue during resistance training prescribed using traditional (TRA) and autoregulation rest-redistribution training (ARRT) approaches. Methods: Twelve resistance-trained men and 12 women completed 2 sessions including the bench-press exercise matched for load (75% of 1-repetition maximum), volume (24 repetitions), and total rest (240 s). Sessions were performed in a counterbalanced randomized design with TRA consisting of 3 sets of 8 repetitions with 120-second interset rest and ARRT employing a personalized combination of clusters, repetitions per cluster, and between-clusters rest regulated with a 20% velocity-loss threshold. The effects of TRA and ARRT on velocity loss, unilateral isometric peak force, and rating of fatigue (ROF) were compared between sexes. Results: The velocity loss was generally lower during ARRT compared with TRA (−0.47% [0.11%]), with velocity loss being mitigated by ARRT to a greater extent among males compared with females (−0.37% [0.15%]). A smaller unilateral isometric peak force decline was observed after ARRT than TRA among males compared with females (−38.4 [8.4] N). Lower ROF after ARRT than TRA was found among males compared to females (−1.97 [0.55] AU). Additionally, males reported greater ROF than females across both conditions (1.92 [0.53] AU), and ARRT resulted in lower ROF than TRA overall (−0.83 [0.39] AU). Conclusions: The ARRT approach resulted in decreased velocity loss, peak force impairment, and ROF compared with TRA in both sexes. However, male subjects exhibited more pronounced acute within-session benefits from the ARRT method. [ABSTRACT FROM AUTHOR]

Purpose: To explore the association of the load–velocity (L-V) relationship variables and ability to maintain maximal mechanical performance during the prone bench-pull exercise with sprint swimming performance and in-water forces. Methods: Eleven competitive adult male swimmers (50-m front crawl World Aquatics points: 488 [66], performance level 4) performed 1 experimental session. The L-V relationship variables (L0 [ie, maximal theoretical load at 0 velocity]; v0 [ie, maximal theoretical velocity at 0 load], and Aline [ie, area under the L-V relationship]) and maximal mechanical maintenance capacity were assessed at the beginning of the session. Afterward, sprint swimming performance and in-water force production were tested through a 50-m front-crawl all-out trial and 15-s fully-tethered swimming, respectively. Results: Only v0 presented high positive associations with 50-m time and swimming kinematics (r >.532; P <.046). The L0, v0, and Aline showed very high positive associations with the in-water forces during tethered swimming (r >.523; P <.049). However, the ability to maintain maximal mechanical performance, assessed by the mean velocity decline during the prone bench pull, was only significantly correlated with stroke rate (r = −.647; P =.016) and stroke index (r =.614; P =.022). Conclusions: These findings indicate that maximal neuromuscular capacities, especially v0, have a stronger correlation with swimming performance and in-water force production than the ability to maintain maximal mechanical performance in level 4 swimmers. [ABSTRACT FROM AUTHOR]

Context: A reduced knee extensor moment (KEM) in the involved limb and asymmetry in the KEM during landing tasks are observed after anterior cruciate ligament reconstruction (ACLR). There is limited information about the association of kinetic and kinematic parameters with the KEM during landing after ACLR. This study investigated the association of the anterior--posterior center of pressure (AP-COP) position, vertical ground reaction force (VGRF), and lower limb joint angles with the KEM during landing in female athletes following ACLR. Design: Cross-sectional study. Methods: Twenty-two female athletes who underwent ACLR performed a drop vertical jump at 7.9 (1.7) months after surgery. We evaluated the KEM, AP-COP position, VGRF, and sagittal plane hip, knee, and ankle angles using a 3-dimensional motion analysis system with force plates. Results: The peak KEM in the involved limb was significantly smaller than that in the uninvolved limb during landing (1.43 [0.33] N·m/kg/m vs 1.84 [0.41] Nm/kg/m, P = .001). The VGRF in the involved limb was significantly smaller than that in the uninvolved limb (11.9 [2.3] N/kg vs 14.6 [3.5] N/kg, P = .005). The limb symmetry index of the KEM was predicted by that of the VGRF (P < .001, R² = .621, β = 0.800). The KEM was predicted by the AP-COP position in the involved limb (P = .015, R² = .227, β = 0.513) and by the VGRF in the uninvolved limb (P = .018, R² = .213, β = 0.500). No significant correlation was noted between the KEM and the lower limb joint angles. Conclusions: The AP-COP position and VGRF were associated with the KEM during landing. Evaluating the VGRF and AP-COP position, not the lower limb joint angles, may contribute to understanding the KEM during double-leg landing after ACLR in the clinical setting. [ABSTRACT FROM AUTHOR]

Disruptions in gait function are common after concussion in adolescents; however, the neuromotor control deficits driving these gait disruptions are not well known. Fifteen concussed (age mean [SD]): 17.4 [0.6], 13 females, days since injury: 26.3 [9.9]) and 17 uninjured (age: 18.0 [0.7], 10 females) adolescents completed 3 trials each of single-task gait and dual-task gait (DT). During DT, participants simultaneously walked while completing a serial subtraction task. Gait metrics and variability in instantaneous mean frequency in lower extremity muscles were captured by inertial sensors and surface electromyography, respectively. A 2-way analysis of covariance was used to compare gait metrics across groups and conditions. Functional principal components analysis was used to identify regions of variability in instantaneous mean frequency curves. Functional principal component scores were compared across groups using a Welch statistic. Both groups displayed worse performance on gait metrics during DT condition compared to single-task, with no differences between groups (P <.001). Concussed adolescents displayed significantly greater instantaneous mean frequency, indicated by functional principal component 1, in the tibialis anterior, biceps femoris, and semitendinosus (P <.05) during single-task and DT compared with uninjured adolescents. Our observations suggest that concussed adolescents display inefficient motor unit recruitment lasting longer than 2 weeks following injury, regardless of the addition of a secondary task. [ABSTRACT FROM AUTHOR]

The hamstring plays an important role in reducing loads born by the anterior cruciate ligament. As anterior cruciate ligament injuries occur rapidly after ground contact, how the hamstring is activated prior to landing can influence injury risk. The purpose was to determine sex-related differences in hamstring activation immediately before landing and the effect of fatigue on "preactivation." Twenty-four participants (13 males and 11 females, age = 24.3 [6.5] y, mass = 72.2 [19.3] kg, height = 169 [9.7] cm) participated in this study. Participants completed a drop-vertical jump protocol before and after a lower body fatigue protocol. Hamstring electromyography (EMG) amplitude at 5 periods prior to landing, peak vertical ground reactions forces (in newtons/body weight), rate of loading (in body weight/second), and landing error scoring system were measured. Females had higher EMG amplitude before and after fatigue (P <.024), with decreased EMG amplitude for both sexes after fatigue (P =.025). There was no change on vertical ground reaction force, rate of loading, or landing error scoring system. Males and females demonstrated similar landing performance before and after fatigue but have different hamstring neuromuscular coordination strategies. The acute reduction in hamstring EMG amplitude following fatigue may increase loading on the anterior cruciate ligament. [ABSTRACT FROM AUTHOR]

Objective. This study aims to develop and validate an end-to-end software platform, PyHFO, that streamlines the application of deep learning (DL) methodologies in detecting neurophysiological biomarkers for epileptogenic zones from EEG recordings.Approach. We introduced PyHFO, which enables time-efficient high-frequency oscillation (HFO) detection algorithms like short-term energy and Montreal Neurological Institute and Hospital detectors. It incorporates DL models for artifact and HFO with spike classification, designed to operate efficiently on standard computer hardware.Main results. The validation of PyHFO was conducted on three separate datasets: the first comprised solely of grid/strip electrodes, the second a combination of grid/strip and depth electrodes, and the third derived from rodent studies, which sampled the neocortex and hippocampus using depth electrodes. PyHFO demonstrated an ability to handle datasets efficiently, with optimization techniques enabling it to achieve speeds up to 50 times faster than traditional HFO detection applications. Users have the flexibility to employ our pre-trained DL model or use their EEG data for custom model training.Significance. PyHFO successfully bridges the computational challenge faced in applying DL techniques to EEG data analysis in epilepsy studies, presenting a feasible solution for both clinical and research settings. By offering a user-friendly and computationally efficient platform, PyHFO paves the way for broader adoption of advanced EEG data analysis tools in clinical practice and fosters potential for large-scale research collaborations.

Postural instability is a detrimental and often treatment-refractory symptom of Parkinsons disease. While many existing studies quantify the biomechanical deficits among various postural domains (static, anticipatory, and reactive) in this population, less is known regarding the neural network dysfunctions underlying these phenomena. This review will summarize current studies on the cortical and subcortical neural activities during postural responses in healthy subjects and those with Parkinsons disease. We will also review the effects of current therapies, including neuromodulation and feedback-based wearable devices, on postural instability symptoms. With recent advances in implantable devices that allow chronic, ambulatory neural data collection from patients with Parkinsons disease, combined with sensors that can quantify biomechanical measurements of postural responses, future work using these devices will enable better understanding of the neural mechanisms of postural control. Bridging this knowledge gap will be the critical first step towards developing novel neuromodulatory interventions to enhance the treatment of postural instability in Parkinsons disease.

Schizophrenia, a complex and debilitating mental disorder, affects approximately 1% of the global population. Diagnosing schizophrenia is challenging due to its heterogeneous symptomatology and lack of objective biomarkers. Electroencephalography (EEG) has emerged as a promising modality for investigating the underlying neurophysiological mechanisms of schizophrenia. In this study, we introduce a novel deep learning model called ResDense Fusion, which leverages residual connections for feature extraction, tackling the issue of vanishing gradients in deep networks. Additionally, during classification, each layer within ResDense Fusion is connected to every other layer in a feed-forward manner within a dense block. ResDense Fusion model integrates the hierarchical feature extraction capabilities of ResNet with the dense feature reuse mechanism of DenseNet, aiming to capture both low-level and high-level representations from EEG signals. By combining these architectures, the model can effectively learn discriminative features relevant to schizophrenia pathology. We evaluated the performance of the ResDense Fusion model on a dataset comprising EEG recordings from schizophrenia patients and healthy controls. Implemented in Python and results demonstrate the efficacy of the proposed model, achieving an impressive accuracy of 96%. The findings of this study highlight the potential of deep learning approaches in harnessing EEG data for schizophrenia diagnosis. The ResDense Fusion model not only offers a powerful tool for detecting schizophrenia but also provides insights into neurobiological underpinnings of the disorder. Ultimately, the development of accurate and efficient diagnostic tools like the ResDense Fusion model has the potential to improve early detection, treatment planning, and patient outcomes in schizophrenia management. [ABSTRACT FROM AUTHOR]

Neuroscientific accounts of music-theoretical topics are increasingly prominent. It is important to critically examine the challenges and contributions of incorporating neuroscience into music studies. Such examination allows for more meaningful integration and leads to better designed experiments that are appropriately sensitive to the historical and cultural situatedness of the topics they investigate. Here I discuss three contributions and three challenges. The contributions are mechanistic explanations (which identify entities and activities that carry out musical behaviors), comparison (which can unite or distinguish between apparently different or similar behavioral capacities), and the ability to transfer knowledge across domains of inquiry. The challenges are the problem of defining behavior (musical behaviors are underdefined, complicating the attribution of neural data), reverse inference (a logical fallacy complicating the association between neurophysiology and a musical task), and problems from issues of cognitive ontology (i.e., a set of fundamental cognitive capacities). Following this theoretical discussion, I apply the six ideas to recent work on improvisation and syntax (including my own), analyzing the work's value and pitfalls. A final emergent theme from this critical analysis is that music neuroscience makes its best contributions when synthesizing work from other areas of music studies. [ABSTRACT FROM AUTHOR]

Introduction: Acute lower back pain can lead to neuroplastic changes in the central nervous system, and symptoms of central sensitization after 12 weeks. While sensory sensitivity has been shown to predict symptoms of central sensitization, trait sensory profiles may be prognostic in the persistence of central sensitization symptoms in low back pain over time. Objective: To examine sensory profiles as prognostic symptoms of central sensitization in people with acute low back pain. Methods: A longitudinal type 2 prognostic factor research study was performed according to the PROGRESS framework. Baseline and 12-week follow-up measures were taken using the Adolescent/Adult Sensory Profile and the Central Sensitization Inventory measures. Study participants were consecutively included from primary care physiotherapy practices. Univariable, and multivariable regression analyses were performed to adjust sensory profiles based on previous history of low back pain, baseline Central Sensitization Inventory scores, level of pain, disability, age, and duration of low back pain. Results: After adjustment, the sensory profiles of Low Registration B = 0.44, 95%CI (0.18, 0.70), Sensation Seeking B = 0.38, 95%CI (0.19, 0.57), Sensory Sensitive B = 0.49, 95%CI (0.25, 0.74), Sensation Avoiding B = 0.40, 95% CI (0.15, 0.65) was significantly associated with the persistence of central sensitization symptoms (N = 103). Conclusion: Sensory profiles may predict symptoms of central sensitization after 12 weeks in people with acute low back pain. [ABSTRACT FROM AUTHOR]

The use of F-wave study may help to gain insight into electrophysiological significance of spinocerebellar Ataxias (SCAs). Particularly, the difference of F-wave features between Chinese SCA1, SCA2 and SCA3 patients were scarcely reported. 20 SCA1, 20 SCA2, 46 SCA3 patients and 30 healthy controls underwent nerve (median, ulnar, tibial) conduction and F-wave studies, and electrophysiology parameters were compared between them. Clinical data including ataxia and non-ataxia features was recorded. The study revealed peripheral neuropathological involvement in 80% of SCA1, 100% of SCA2, and 50% of SCA3 Chinese patients. Most patients of all subtypes presented with sensory neuropathy, and F-wave changes. We observed that SCA1 patients had prolonged F-wave latency as well as increased maximum F-wave amplitude and F/M amplitude ratio compared to controls for the first time. Besides, SCA2 patients had decreased F-wave persistence as well as increased maximum F-wave amplitude, F/M amplitude ratio and frequency of giant F-wave. The maximum amplitude of SCA1 correlated positively with disease severity and disease duration. The value of F/M amplitude ratio of SCA2 correlated positively with disease duration. In all subtypes, F-wave of the tibial nerve was the most sensitive measurement index. This study exhibits F-wave characteristics and inter-group differences of the most common Chinese SCAs. F-wave may be a potential biomarker for evaluating the progression of SCAs. [ABSTRACT FROM AUTHOR]

Purpose: Reduced force control after anterior cruciate ligament (ACL) injury and reconstruction may contribute to poor function. Various metrics (linear and nonlinear) have been employed to quantify force control. The aims of this review were to synthesize evidence assessing knee extensor and flexor force control after ACL injury (ACLD) or reconstruction (ACLR) and to investigate the potential effects of injury management (e.g., surgery, graft type), mode of contraction (e.g., isometric, isokinetic), and speed and intensity of contraction. Methods: We searched six databases for studies assessing knee extensor or flexor force control in individuals with ACLD or ACLR using a linear or nonlinear analysis method and comparing to the uninvolved limb or an uninjured control. Two independent reviewers assessed potential studies for inclusion and quality. Primary random effects meta-analyses were simultaneously separated by muscle, injury management, analysis method, and comparator. Results: Twenty-seven studies were included. When assessed via linear methods, greater variability in knee extensor force (i.e., reduced force control) was observed only in comparison to uninjured controls (ACLD: P = 0.03, Hedges' g = 0.22, [95% confidence interval CI 0.02–0.42]; ACLR: P = 0.01, Hedges' g = 0.23, [95% CI = 0.05–0.41]). When assessed via nonlinear methods, lesser regularity of knee extensor force control (i.e., reduced force control) was observed in comparison to the uninvolved limb (ACLD: P = 0.008, Hedges' g = 0.44, [95% CI = 0.11–0.76]; ACLR: P < 0.00001, Hedges' g = 0.75, [95% CI = 0.61–0.88]) and uninjured controls (ACLD: P = 0.002, Hedges' g = 0.44, [95% CI = 0.16–0.72]; ACLR: P < 0.00001, Hedges' g = 0.69, [95% CI = 0.55–0.82]). Funnel plot data suggested a potential risk of bias. Conclusions: Moderate-to-strong evidence indicates impaired knee extensor force control after ACLR in comparison to uninjured controls, regardless of analysis type. Nonlinear analyses detected more and greater force control differences, thus appearing to be more sensitive and highlighting a need for a standardized, clinically accessible methodology. These results may be partially explained by the neuromuscular mechanisms underlying motor control. [ABSTRACT FROM AUTHOR]

Magnetoencephalography (MEG) is an imaging technique that enables the assessment of cortical activity via direct measures of neurophysiology. It is a non-invasive and passive technique that is completely painless. MEG has gained increasing prominence in the field of pediatric neuroimaging. This dedicated review article for the pediatric population summarizes the fundamental technical and clinical aspects of MEG for the clinician. We discuss methods tailored for children to improve data quality, including child-friendly MEG facility environments and strategies to mitigate motion artifacts. We provide an in-depth overview on accurate localization of neural sources and different analysis methods, as well as data interpretation. The contemporary platforms and approaches of two quaternary pediatric referral centers are illustrated, shedding light on practical implementations in clinical settings. Finally, we describe the expanding clinical applications of MEG, including its pivotal role in presurgical evaluation of epilepsy patients, presurgical mapping of eloquent cortices (somatosensory and motor cortices, visual and auditory cortices, lateralization of language), its emerging relevance in autism spectrum disorder research and potential future clinical applications, and its utility in assessing mild traumatic brain injury. In conclusion, this review serves as a comprehensive resource of clinicians as well as researchers, offering insights into the evolving landscape of pediatric MEG. It discusses the importance of technical advancements, data acquisition strategies, and expanding clinical applications in harnessing the full potential of MEG to study neurological conditions in the pediatric population. [ABSTRACT FROM AUTHOR]

Low back pain among physical therapists is a common musculoskeletal disorder that first occurs early in their career or as a student. This observational prospective study assessed the ability of hip and lumbopelvic neuromuscular control, endurance and hip range of motion tests to predict the development of transient low back pain development during a standing task. Seventy-two physical therapy students without low back pain completed nine performance tests and a 2-hour standing test on two separate days. Participants were classified as transient pain developers (PD) if they reported a ≥ 10mm increase in low back pain on a visual analog scale. Transient back pain was reported by 37.5% of students during the standing test. A cluster of three positive tests, self-rated active hip abduction (somewhat difficult or more), bilateral total hip internal rotation greater than 81 degrees, and non-dominant limb single-leg squat (moderate deviations), demonstrated an increased probability (94.9%) of identifying PDs. Negative findings on the same three tests decreased the probability to 10.7%. Overall, the classification accuracy for the three-test model was 72.2%. The sensitivity for the model was 63% and the specificity was 77.8%. PRACTITIONER SUMMARY: A 3-test cluster of poor hip and lumbopelvic neuromuscular control and increased hip internal rotation range of motion is an effective screening tool for identifying physical therapy students who are most likely and least likely to develop transient LBP during 2 hours of standing. [ABSTRACT FROM AUTHOR]

Background: Bipolar disorder is a serious mental illness, which requires new strategies for prevention and management. Recent evidence suggests that a ketogenic diet may be an effective intervention. This research aimed to explore the feasibility and acceptability of a ketogenic diet intervention for bipolar disorder, fidelity to its behavioural components and the experiences of the participants and research clinicians involved. Methods: A mixed-methods process evaluation was conducted. Semi-structured telephone interviews were carried out with 15 participants 1–2 months after completing a 6–8 week modified ketogenic diet intervention, and 4 research clinicians from the study team following the completion of data collection. Data were thematically analysed. Fidelity checklists completed by research dietitians were analysed using descriptive count and percentage statistics. Findings are reported post-hoc, following the analysis and publication of the main pilot study findings. Reporting was guided by the COREQ checklist. Results: Five themes were identified in the qualitative data: (1) 'Encouraging entry and supporting exit' (e.g. recognising and managing participants' varied motives and expectations, including around weight loss and symptom alleviation); (2) 'Challenging but potentially transformational,' which reflects that while it can be difficult to initiate and maintain a ketogenic diet day-to-day, many participants perceived physical and psychological benefits (e.g. significant weight loss, mood stability and enhanced ability to focus); (3) 'Intervention facilitators,' including a range of behavioural (e.g. goal setting), social (e.g. family and dietitians) and technological (e.g. apps for monitoring) support mechanisms; (4) 'Intervention barriers' (e.g. dietary preferences, concerns about the diet and its impact, the testing burden and capacity of the delivery team); and (5) 'The wider context' (e.g. the cost of living and sociocultural expectations) was a crucial factor explaining differential experiences. Overall, descriptive analyses indicated moderate-to-good fidelity to the behaviour change components of the study. Conclusion: We provide novel insight into the experiences of people living with bipolar disorder initiating and following a ketogenic diet, as well as those of research clinicians who support the intervention. Future trials may benefit from increased clinical research capacity, better-defined entry and exit routes, additional interpersonal support, and greater understanding of how social and societal factors impact participation. Trial registration: Study registration number: ISRCTN61613198 (02/03/22). [ABSTRACT FROM AUTHOR]

The article discusses the importance of STEM education in human movement sciences, particularly focusing on surface electromyography (sEMG) as an example. It highlights the need for interdisciplinary courses to train future professionals in fields like sport and exercise physiology, physiotherapy, and clinical environments. The proposed syllabus for a course on sEMG covers fundamental concepts in mathematics, physics, electrophysiology, and signal processing, emphasizing the importance of a strong STEM-oriented approach in various disciplines. The authors stress the necessity of educating teachers and students on these topics to improve the quality of outputs and promote evidence-based practices in healthcare. [Extracted from the article]

Precision, or personalized, medicine aims to stratify patients based on variable pathogenic signatures to optimize the effectiveness of disease prevention and treatment. This approach is favorable in the context of brain disorders, which are often heterogeneous in their pathophysiological features, patterns of disease progression and treatment response, resulting in limited therapeutic standard-of-care. Here we highlight the transformative role that human induced pluripotent stem cell (hiPSC)-derived neural models are poised to play in advancing precision medicine for brain disorders, particularly emerging innovations that improve the relevance of hiPSC models to human physiology. hiPSCs derived from accessible patient somatic cells can produce various neural cell types and tissues; current efforts to increase the complexity of these models, incorporating region-specific neural tissues and non-neural cell types of the brain microenvironment, are providing increasingly relevant insights into human-specific neurobiology. Continued advances in tissue engineering combined with innovations in genomics, high-throughput screening and imaging strengthen the physiological relevance of hiPSC models and thus their ability to uncover disease mechanisms, therapeutic vulnerabilities, and tissue and fluid-based biomarkers that will have real impact on neurological disease treatment. True physiological understanding, however, necessitates integration of hiPSC-neural models with patient biophysical data, including quantitative neuroimaging representations. We discuss recent innovations in cellular neuroscience that can provide these direct connections through generative AI modeling. Our focus is to highlight the great potential of synergy between these emerging innovations to pave the way for personalized medicine becoming a viable option for patients suffering from neuropathologies, particularly rare epileptic and neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

Introduction: Physical exercise has repeatedly been reported to have advantageous effects on brain functions, including learning and memory formation. However, objective tools to measure such effects are often lacking. Eyeblink conditioning is a well-characterized method for studying the neural basis of associative learning. As such, this paradigm has potential as a tool to assess to what extent exercise affects one of the most basic forms of learning. Until recently, however, using this paradigm for testing human subjects in their daily life was technically challenging. As a consequence, no studies have investigated how exercise affects eyeblink conditioning in humans. Here we hypothesize that acute aerobic exercise is associated with improved performance in eyeblink conditioning. Furthermore, we explored whether the effects of exercise differed for people engaging in regular exercise versus those who were not. Methods: We conducted a case–control study using a smartphone-based platform for conducting neurometric eyeblink conditioning in healthy adults aged between 18 and 40 years (n = 36). Groups were matched on age, sex, and education level. Our primary outcome measures included the amplitude and timing of conditioned eyelid responses over the course of eyeblink training. As a secondary measure, we studied the amplitude of the unconditioned responses. Results: Acute exercise significantly enhanced the acquisition of conditioned eyelid responses; however, this effect was only true for regularly exercising individuals. No statistically significant effects were established for timing of the conditioned responses and amplitude of the unconditioned responses. Discussion: This study highlights a facilitative role of acute aerobic exercise in associative learning and emphasizes the importance of accounting for long-term exercise habits when investigating the acute effects of exercise on brain functioning. [ABSTRACT FROM AUTHOR]

Blink-related oscillations (BROs) are newly discovered neurophysiological brainwave responses associated with spontaneous blinking, and represent environmental monitoring and awareness processes as the brain evaluates new visual information appearing after eye re-opening. BRO responses have been demonstrated in healthy young adults across multiple task states and are modulated by both task and environmental factors, but little is known about this phenomenon in aging. To address this, we undertook the first large-scale evaluation of BRO responses in healthy aging using the Cambridge Centre for Aging and Neuroscience (Cam-CAN) repository, which contains magnetoencephalography (MEG) data from a large sample (N = 457) of healthy adults across a broad age range (18–88) during the performance of a simple target detection task. The results showed that BRO responses were present in all age groups, and the associated effects exhibited significant age-related modulations comprising an increase in sensor-level global field power (GFP) and source-level theta and alpha spectral power within the bilateral precuneus. Additionally, the extent of cortical activations also showed an inverted-U relationship with age, consistent with neurocompensation with aging. Crucially, these age-related differences were not observed in the behavioral measures of task performance such as reaction time and accuracy, suggesting that blink-related neural responses during the target detection task are more sensitive in capturing aging-related brain function changes compared to behavioral measures alone. Together, these results suggest that BRO responses are not only present throughout the adult lifespan, but the effects can also capture brain function changes in healthy aging—thus providing a simple yet powerful avenue for evaluating brain health in aging. [ABSTRACT FROM AUTHOR]

Introduction: Amyotrophic lateral sclerosis (ALS) is a complex, progressive neurodegenerative disorder characterized by the degeneration of motor neurons in the brain, brainstem, and spinal cord. Several neuroimaging techniques can help reveal the pathophysiology of ALS. One of these is the electroencephalogram (EEG), a noninvasive and relatively inexpensive tool for examining electrical activity of the brain with excellent temporal precision. Methods: This mechanistic review examines the pattern of resting-state EEG activity. With a focus on publications published between January 1995 and October 2024, we carried out a comprehensive search in October 2024 across a number of databases, including PubMed/Medline, Research Gate, Google Scholar, and Cochrane. Results: The literature search yielded 17 studies included in this review. The studies varied significantly in their methodology and patient characteristics. Despite this, a common biomarker typical of ALS was found—reduced alpha power. Regarding other oscillations, the findings are less consistent and sometimes contradictory. As this is a mechanistic review, three possible explanations for this biomarker are provided. The main and most important one is increased cortical excitability. In addition, due to the limitations of the studies, recommendations for future research on this topic are outlined to enable a further and better understanding of EEG patterns in ALS. Conclusions: Most studies included in this review showed alpha power deficits in ALS patients, reflecting pathological hyperexcitability of the cerebral cortex. Future studies should address the methodological limitations identified in this review, including small sample sizes, inconsistent frequency-band definitions, and insufficient functional outcome measures, to solidify and extend current findings. [ABSTRACT FROM AUTHOR]

Autism spectrum disorder (ASD) comprises alterations in brain anatomy and physiology that ultimately affect information processing and behavior. In most cases, autism is considered idiopathic, involving alterations in numerous genes whose functions are not extensively documented. We evaluated the C58/J mouse strain as an idiopathic model of ASD, emphasizing synaptic transmission as the basis of information processing. Through in silico analysis, we found that the C58/J strain carries single nucleotide polymorphisms (SNPs) compared to the C57BL/6J control strain related to synaptic structure and LTP induction. These SNPs have human orthologs previously associated with ASD. We then assessed chemical potentiation (cLTP) in synaptosomes, the electrophysiological properties of hippocampal CA3 cells, and the induction of LTP in ex-vivo slices. An increased proportion of synaptosomes expressing the GluA1 subunit of AMPA receptor and Nrx1β in the membrane was found in the C57BL/6J control strain, but not in C58/J mice, after cLTP induction. Additionally, several electrophysiological properties of CA3 pyramidal cells and hippocampal communication were altered. Behaviorally, C58/J mice exhibited hyperactivity and subtle memory changes. Our results demonstrate that an idiopathic model of ASD exhibits alterations in hippocampal physiology from the cellular to the circuitry and behavioral levels. [ABSTRACT FROM AUTHOR]

Objective Methods Results Significance Cognitive deficits are one of the most debilitating comorbidities in epilepsy and other neurodegenerative, neuropsychiatric, and neurodevelopmental brain disorders. Current diagnostic and therapeutic options are limited and lack objective measures of the underlying neural activities. In this study, electrophysiological biomarkers that reflect cognitive functions in clinically validated batteries were determined to aid diagnosis and treatment in specific brain regions.We employed the Cambridge Neuropsychological Test Automated Battery (CANTAB) tasks to probe memory and executive functions in 86 patients with epilepsy undergoing clinical electroencephalography (EEG) monitoring. EEG electrode signals during performance of particular battery tasks were decomposed to identify specific frequency bands and cortical areas that differentiated patients with impaired, normal, and good standardized performance according to their age and gender.The anterior prefrontal cortical EEG power in the theta frequency band was consistently lower in patients with impaired memory and executive function performance (z‐score < −1). This effect was evident in all four behavioral measures of executive, visual, spatial, and working memory functions and was confined to the cortical area of all four frontal pole electrodes (Nz, Fpz, Fp1, and Fp2).Theta EEG power in the anterior prefrontal cortex provides simple, accessible, and objective electrophysiological measure of memory and executive functions in epilepsy. Our results suggest a feasible clinical biomarker for diagnosis, monitoring, and treatment of cognitive deficits with emerging targeted neuromodulation approaches. [ABSTRACT FROM AUTHOR]

Autism has been conceptualized as a neurodevelopmental disorder and as a different form of human cognition. From a neurophysiological perspective, the mirror neuron system (MNS) in autism has been investigated, focusing on measurable data. Neurophenomenology proposes to integrate scientific evidence with subjective experience. Objective: to understand the relationship between subjectivity and the brain, covering the neural processes involved in autism and the first-person experience of a group of children and adolescents from the city of Manizales. Methodology: mixed research, descriptive and inferential, including qualitative information, approached from an interpretive phenomenological approach. 35 children between 6 and 16 years old and 19 control peers participated. Results: autistic participants demonstrated greater heterogeneity in the behavior of the MNS and in their relationship with the world, both with respect to control participants and among themselves. A proposal for inclusive education called "Neurodiversity" was built, which won second place in the Premio Cívico Retos con los ODS. Conclusions: the importance of integrating neurophysiological evidence with first-person experience was demonstrated, allowing a broad understanding of the object of study and its applications in context. [ABSTRACT FROM AUTHOR]

The brain represents the world through the activity of neural populations; however, whether the computational goal of sensory coding is to support discrimination of sensory stimuli or to generate an internal model of the sensory world is unclear. Correlated variability across a neural population (noise correlations) is commonly observed experimentally, and many studies demonstrate that correlated variability improves discriminative sensory coding compared to a null model with no correlations. However, such results do not address whether correlated variability is optimal for discriminative sensory coding. If the computational goal of sensory coding is discriminative, than correlated variability should be optimized to support that goal. We assessed optimality of noise correlations for discriminative sensory coding in diverse datasets by developing two novel null models, each with a biological interpretation. Across datasets, we found that correlated variability in neural populations leads to highly suboptimal discriminative sensory coding according to both null models. Furthermore, biological constraints prevent many subsets of the neural populations from achieving optimality, and subselecting based on biological criteria leaves red discriminative coding performance suboptimal. Finally, we show that optimal subpopulations are exponentially small as the population size grows. Together, these results demonstrate that the geometry of correlated variability leads to highly suboptimal discriminative sensory coding. NEW & NOTEWORTHY: The brain represents the world through the activity of neural populations that exhibit correlated variability. We assessed optimality of correlated variability for discriminative sensory coding in diverse datasets by developing two novel null models. Across datasets, correlated variability in neural populations leads to highly suboptimal discriminative sensory coding according to both null models. Biological constraints prevent the neural populations from achieving optimality. Together, these results demonstrate that the geometry of correlated variability leads to highly suboptimal discriminative sensory coding. [ABSTRACT FROM AUTHOR]

In many species, olfactory abilities in females are more acute than those in males. Studies in humans show that women have lower olfactory thresholds and are better able to discriminate and identify odors than men. In mice, odorants elicit faster activation from a larger number of olfactory bulb glomeruli in females than in males. Our study explores sex differences in olfaction in Long Evans rats from a behavioral and electrophysiological perspective. Local field potentials (LFPs) in the olfactory bulb (OB) represent the coordinated activity of bulbar neurons. Olfactory gamma (65–120 Hz) and beta (15–30 Hz) oscillations have been functionally linked to odor perception. Spontaneous and odor-evoked OB LFPs were recorded from awake rats at the same time for 12 days. Odors used included urine of both sexes and monomolecular odorants characterized previously for correlation of volatility with behavior and OB oscillations. Sampling duration in a habituation context, baseline gamma and beta power, and odor-elicited beta and gamma power were analyzed. We find that females sample odorants for a shorter duration than males (just over 1-s difference). Although baseline gamma and beta power do not show significant differences between the two sexes, odor-elicited gamma and beta power in females is significantly lower than in males. Neither sampling duration nor beta and gamma power in females varied systematically with day of estrus. We further verify that variance of these behavioral and physiological measures is not different across sexes, adding to growing evidence that researchers need not be concerned about often-claimed additional variance in female subjects. NEW & NOTEWORTHY: Olfaction plays a large role in evolutionary processes. However, we know little about sex differences in olfactory bulb neurophysiology, and many scientists believe that females are more variable because of estrus. We show that female rats sniff odors for shorter durations than males and have lower power in neural oscillations related to cognition. Estrus was not related to variance in any measures. Finally, males and females show equal variance on these behavioral and physiological processes. [ABSTRACT FROM AUTHOR]