Motor sequence learning (MSL) involves transitioning from reactive, stimulus-led control to predictive, automated execution. While expertise is traditionally quantified by speed and accuracy, the underlying organizational shifts in fractal movement variability remain poorly understood. We propose the Readiness-Efficiency hypothesis: expertise emerges through a functional coupling of high preparatory complexity and reduced execution complexity. Participants (n = 22) performed a whole-body Dance Discrete Sequence Production task while Center of Mass (CoM) kinematics were recorded. Hurst exponents (H) quantified fractal complexity across ten blocks of practice and transfer. As learning progressed, preparatory dynamics shifted toward higher complexity (Hprep ↑), reflecting structured readiness, while execution dynamics shifted toward reduced complexity (Hexec ↓), reflecting automated efficiency. Crucially, a three-way interaction revealed that the fastest response times were achieved specifically when high preparatory readiness was coupled with reduced execution complexity. This coupling collapsed upon transfer to novel sequences, indicating task-specificity. State-space analysis confirmed the Readiness-Efficiency configuration acts as a functional attractor, with the probability of occupying this state increasing five-fold through practice. These findings demonstrate that expertise is characterized by dynamic flexibility – the capacity to dissociate and pair control regimes to meet phase-specific demands – providing a mechanistic framework for profiling skill acquisition.

Every day, people plan to do something at some point in the future—with varying success remembering to do it. This challenge has inspired decades of research on prospective memory (PM), or how organisms are able to set an intention in the present and successfully execute it later in the future. Dominant theories of PM rely on representational, computational accounts and propose dual-process systems of attentional monitoring and spontaneous retrieval, which we refer to as cue and capacity (C&C) models. We present an alternative grounded in ecological psychology and argue for a more parsimonious account for PM performance through ecological concepts. We propose that directly perceiving information from the environment allows people to move from intention-in-the-present to realization-in-the-future as part of an extended action via nested affordances (or how taking advantage of existing opportunities for action scaffold to reveal opportunities for goal execution). We demonstrate the utility of this approach by drawing on research from skill acquisition in sports, where successful performance depends on coordinating action over time in dynamic environments. Grounded in nested affordances and the tenets of ecological psychology, we will propose a spatiotemporal specificity model and present a future research agenda to explore.

This study aimed to examine the effects of the presence or absence of visual information (eyes open or eyes closed), leg dominance (dominant leg or nondominant leg), and gait speed (normal gait or maximum gait) on gait performance. The participants (30 young adults 21.3 ± 0.8 years) performed 10-m walking tests with a small triaxial accelerometer attached to their waist. They performed normal and maximum gait tests under two conditions: eyes open and eyes closed. The gait performance evaluation parameters were gait speed, stride, step length, cadence, stance phase, swing phase, double support phase and single support phase. The results of Bayesian mixed-effects model analysis showed that visual condition (eyes open) had a positive effect on many parameters during normal gait speed; however, this effect tended to decrease during maximum gait speed. There were no clear effects for leg dominance or its interaction with visual information. These results suggest that visual information plays an important role in gait control and that its effect depends on the gait speed. Therefore, gait evaluation based on differences in gait speed and sensory integration modalities might be useful in understanding the diversity of gait control mechanisms.

Thirty-one children (48% female, 55% White, 4–12 years) and twelve adults (67% female, 67% White, 18–50 years) participated in feasibility and validity testing of the Spatial Movement Sense tests. The Spatial Movement Sense tests assess the participant’s ability to identify shape patterns based on how their hand moves (actively or passively) through a movement pattern without vision. All participants were able to complete the assessment. Results of our assessment are significantly correlated with endpoint position sense and support these tests as a valid proprioception assessment. There were also developmental trends and strong correlations with motor performance. The Spatial Movement Sense tests appear to be a promising tool for assessing proprioception in children.

One of the most important targets after stroke, which is a major cause of disability worldwide, is to improve gait ability. Although many different parameters required for gait improvement are known, determining the key parameters is of great importance. This study aims to identify key parameters that predict gait speed in individuals with stroke, with a particular focus on motor and sensory components. A total of 41 individuals with stroke participated in the study. Gait speed, balance, muscle strength, motor functions, spasticity, proprioception, and plantar cutaneous sensation were assessed by 2-min walk test, Berg Balance Scale, hand-held dynamometer, Fugl Meyer assessment-lower extremity, Modified Modified Ashworth Scale, repositioning error, and Semmes-Weinstein Monofilament Test, respectively. In this study, gait speed was correlated with all parameters except for plantar cutaneous sensation. Balance and lower extremity muscle strength were found to be the main parameters predicting gait speed (Adj. R 2 = 0.656, p < 0.001). Furthermore, hip flexor muscle strength emerged as an important predictor of gait speed among the lower extremity muscle groups (Adj. R 2 = 0.618, p < 0.001). The findings indicate that balance and lower extremity muscle strength, particularly hip flexor muscle strength, may serve as potential targets for interventions to increase gait speed, although the statistical results do not imply causality.

This study investigated the impact of real-time laser-guided visual cues on spatiotemporal gait parameters during initiation and termination in people with Parkinson’s (PwP). Fifteen PwP walked a 5-m path under uncued and laser-cued conditions while gait kinematics and center of pressure (CoP) data were collected. Results revealed that laser-guided visual cues significantly increased anterior-posterior CoP displacement during the propelling phase of gait initiation (p = .016) and improved dynamic stability, evidenced by reduced lateral asymmetry (p = .007) and decreased fractal dimension of lateral gait variability (p = .001). Conversely, step time increased (p = .005) and step velocity decreased (p < .001) with cueing, while step length remained unchanged. No significant effects of cueing were observed during gait termination. These findings suggest that laser-guided visual cues enhance gait initiation in PwP by promoting propulsion and stability, likely by facilitating an external focus of attention and improving anticipatory postural adjustments. The lack of effect on gait termination may reflect differing neural control mechanisms. This study contributes to the understanding of laser-guided visual cueing mechanisms in PwP gait and supports its potential as a targeted intervention for improving functional mobility, particularly during the challenging phase of gait initiation.

Human behavior is influenced by the social context and depends on emotional state. This study focuses on the effect of the presence of others and group in interaction with the emotional impact on motor, cognitive and affective performance. Seventy-four subjects participated in the study. Each participant performed a dart shooting action in three conditions: the individual, presence of others, and group presence. Motion kinematics were detected using Adope Premier software and affective states were recorded using a Deep-learning facial expression recognition model. Performance analysis revealed that subjects performed the task with a shorter reaction time and movement duration during the others’ presence condition as well as the group presence condition compared to the single case. The results thus demonstrate the effect of emotions on movement kinematics and emotional correspondence and stability. This improvement can be attributed to the social facilitation related to the audience effect and motivational factor.

Theories of human motor learning commonly assume that movement plans are adjusted in response to the sensory feedback received about their success or failure. The degree to which movement errors drive changes in feedforward motor plans is further assumed to scale inversely with sensory uncertainty. However, support for these assumptions comes primarily from experiments that limit feedback corrections during an ongoing movement. In contrast, we have recently shown that when this restriction is relaxed, a different pattern of behavior emerges. Participants gradually adjust their reaching movements in response to a perturbation from trial-to-trial, following a consistent and incremental envelope of error reduction. Riding on top of this gradual learning envelope, participants also exhibit large and abrupt changes in their initial reach direction that are strongly correlated with the uncertainty level of the sensory feedback experienced on the previous trial, but are insensitive to the size and direction of the movement error made on that trial. A class of models in which sensory uncertainty influences an aiming process best accounted for this pattern. Here, we examine the possibility that uncertainty acts as a contextual cue to shunt motor processes to one of many context-specific internal models.

There is a lack of research on the effects of fatigue and dual-task motor performance in people with Multiple sclerosis (MS), especially in women. Using a group of 20 women with MS and 20 healthy controls, we examined the effects of fatigue and attentional demands on center of pressure (COP) displacements during upright stance. Anterior-posterior (AP), Media-lateral (ML), and total COP displacements, and also ankle plantar flexors’ strength were measured. Results indicated that fatigue and dual-task resulted in higher ML COP displacements in both groups, but unlike controls, MS patients had higher ML displacements during the dual-task compared to single-task trials. Additionally, while fatigue resulted in an increased single-task AP and total COP displacements in both groups, it yielded higher dual-task AP and total COP displacements only in MS patients. Moreover, MS patients had weaker ankle plantar flexors compared to healthy controls, but the plantar flexors—mainly soleus—maximum voluntary contraction (MVC) was only associated with fatigued single-task balance performance in MS patients. Our study confirmed the adverse effects of fatigue and dual-task on balance performance, especially in MS patients. Further research is required on whether the modulation of balance performance of ankle plantar flexors’ MVC depends on fatigue and attentional task demands.

This study investigates the neurophysiological and biomechanical factors contributing to successful basketball throw performance in novice athletes, utilizing electroencephalography (EEG) and motion capture (MoCap) to analyze joint angles, ground reaction forces (GRFs), and brain activity. Sixteen participants performed basketball throws while EEG and MoCap systems recorded data on movement mechanics and neural activity. Biomechanical findings revealed that successful trials were characterized by refined movements, reduced wrist extension, increased elbow flexion, and more stable foot positioning compared to unsuccessful trials (all p > 0.05), contributing to greater shot accuracy. Reduced movement variability in successful trials further indicated improved motor consistency, reflective of skill development. EEG results showed higher beta and gamma power in the temporal lobe during successful compared to unsuccessful trials (p < 0.05), suggesting increased engagement in visuomotor integration and neural efficiency. Notably, our novice participants demonstrated limited neural efficiency in frontal regions (p > 0.05), potentially due to cognitive interference and self-monitoring. These findings highlight the importance of coordinated biomechanical execution and neural efficiency in optimizing basketball performance. The insights gained have practical implications for designing training interventions that improve motor performance, particularly for novice athletes.