Journal of Motor Behavior最新文献

Gait stability and walking direction control are conventionally attributed to coordination among somatosensory, visual, and vestibular systems. Recent evidence of functional interdependence between masticatory and neuromuscular systems indicates that the stomatognathic system is neurologically integrated with various body systems relevant to movement planning and execution. This study investigated the effects of unilateral molar biting and incisor biting on walking with and without visual feedback. A cohort of 31 healthy young adults aged 21 to 30 years (average age of 23.93 ± 1.89) participated in this study. Three types of errors in walking direction (angle error, position error, and curve error) were computed. Our findings indicate that, in right-handed individuals, irrespective of visual feedback, unilateral biting caused systematic deviations toward the biting side from initiation to termination of walking. The consistent deviation in walking, particularly during unilateral right biting conditions in right-handed individuals, may indicate a complex interplay between masticatory function and gait control mechanism, potentially influenced by handedness and motor lateralization within the cortex. This study establishes a foundation for future research exploring the interrelation between bite location, visual feedback, and motor control in diverse populations. This research may provide insight for more efficient interventions for gait-related disorders.

Cross-education (CE) is a phenomenon whereby motor training of one limb leads to improved performance in the opposite untrained limb. External pacing of a motor task can enhance CE; however, the influence of different pacing methods is poorly understood. This study explored how motor training with auditory (AP) and visual pacing (VP) impacts CE with a visuomotor force target task. Sixty-one participants performed a unimanual motor task. Participants were randomized into a visual (n = 31) or auditory (n = 30) pacing stimuli condition. The primary outcome was cumulative error scores for each hand, before and after visuomotor training. Pacing type did not yield different magnitudes of CE. However, after adjusting for baseline differences, a significant hand (trained vs. untrained) × practice side (dominant or non-dominant) interaction (p = .013, η_p² = .106) and a group main effect (p = .036, η_p² = .165) were observed. Visual pacing resulted in greater improvements in task performance compared to auditory pacing regardless of hand or practice side, while training the dominant limb resulting in a greater interlimb asymmetry regardless of pacing stimulus. These findings have implications for applying pacing strategies during rehabilitation from unilateral injury or neurological impairment.

The functional equivalence model suggests a common internal representation initiates both imagery and execution. This suggestion is supported by the mental chronometry effect, where there is a positive relation between task difficulty (as defined by the Index of Difficulty; ID) and imagined movement time. The present study extends this logic by examining whether imagery captures the spatial trajectory. Participants were initially tasked with the imagery and execution of a rapid aiming movement under different IDs. These initial attempts were adapted to configure auditory tones at early (25%) and late (75%) intervals for a separate set of imagery trials. If a tone had sounded, participants had to estimate post-trial where their imagined limb would have been located. The findings revealed increases in ID that coincided with increases in imagined and executed movement times. However, participant mean and standard deviation of estimated locations revealed limited differences between the early and late tones. Further inspection revealed some evidence for these estimated locations shifting further along in space following more rapid imagined movements. While equivalence is clearly evident within the temporal domain, there is comparatively little to suggest that this logic extends to the resolution required for simulating the spatial characteristics of movement.

Motor competence is associated with the perceived difficulty of a task. This study hypothesized that children with higher motor competence perceive certain tasks as less challenging than their peers with lower motor competence. As a result, children with higher motor competence were expected to set more ambitious goals for themselves while learning a new task compared to children with lower motor competence. To investigate the relationship between motor competence and the difficulty of self-set goals during motor learning, we included 48 children aged between eight and ten years, stratified into terciles; our analysis focused on 32 children from the highest and lowest terciles. The experimental task required participants to throw a 100 g bean bag toward a target located 3 meters away. Children were instructed to set goals before each block of 10 trials during the learning phase. Pretest, retention, and transfer tests were administered without imposed goals. Motor competence was assessed using the Motor Competence Assessment, which integrates scores from the task used to evaluate motor learning and the percentage increase in each block to assess the difficulty of the self-set goals. The findings revealed no significant correlation between motor competence and the difficulty of self-set goals. Nevertheless, higher motor competence was linked to enhanced performance during the acquisition phase, retention and transfer tests. These results suggest that although motor competence is associated with improved motor learning, it does not influence the level of challenge of the goals that children set for themselves.

According to Fitts' law, an individual's speed-accuracy tradeoff is only related to the object's properties. According to previous research, the movement time to hit the current target can be affected by the target of different size on the previous trial where the Fitts' law task is affected by trial history. However, in a dyadic context, the question is whether there is still a trial-to-trial transfer across individuals. In this study, Experiment 1 was conducted to investigate whether the current trial would be affected by the previous trial performed by the partner in a dyadic task. The results showed trial-to-trial transfer between individuals was affected by the difficulty of the action. The current movement was only affected by the previous difficult trial but not simple task. In order to investigate whether observing only novel targets would affect the current movement, we conducted Experiment 2, which showed that observing the target was not sufficient to generate effect transfer between trials. These findings suggest that the goal-directed movement can be affected by the observation of others. In addition, the effect of trial-to-trial transfer between individuals was influenced by task difficulty, which proved this effect was not a simple imitation.

The present experiment used the Serial Reaction Time Task(SRTT) to investigate if auditory cueing or feedback in the form of spatially compatible tones benefited sequence learning similarly. Fifty-three neurotypical adults (18-35 years; 32 cis-females; 21 cis-males) were randomly assigned to three groups in which they practiced a visual SRTT: Group AC was supplemented with auditory cues; group AF received auditory feedback; group NS performed without sound. Retention and transfer tests (i.e., in the other two sensory conditions), and an explicit awareness test were conducted 48 h after practice. Changes in Total Sequence Time (TST), Total Error (TE), and acquired knowledge of the 10-item sequence order quantified sequence learning and were assessed using a two-way mixed ANOVA with repeated measures (p ≤ 0.05). A significant group-by-time interaction indicated only the AC group maintained their performance improvements when the sequence was perturbed. Overall, improvements in TST on day 1 and day 2 were consistent with all groups acquiring task-general and sequence-specific knowledge. TE outcomes suggested no speed-accuracy tradeoff. On Day 2, all groups performed best in the no-sound condition, indicating performance was maintained when sound cues or feedback were removed. All groups acquired equivalent implicit motor sequence knowledge regardless of sound condition.

Performance of sport-related ballistic motor skills, like ball hitting in golf and baseball, requires wide movements to produce highly fast and spatially accurate movements. In this study, we assessed the effect of movement amplitude on directional accuracy in a ballistic hitting task. Participants performed the task of moving a manual handle over a flat surface to hit with high speed a moveable disc, aiming to propel it towards a frontal target. Five movement amplitudes were compared, ranging from 11.5 cm to 27.5 cm in steps of 4 cm. Kinematic analysis evaluated motions of the handle, disc, and arm joints. Results showed that greater movement amplitudes led to longer acceleration phases, with delayed peak velocities at the handle, shoulder and elbow, leading to higher contact and peak linear velocities of the handle, and higher angular velocities at the shoulder and elbow. Manipulation of movement amplitude led to no evidence for effects on either disc directional accuracy or variability. Results also revealed no evidence for differences in variability of contact velocity, peak velocity and time of peak velocity across movement amplitudes in the shoulder, elbow, and wrist. Our results indicated that greater movement amplitudes in hitting a spatial target lead to increased contact velocity while not affecting directional accuracy or movement variability.

This research examined how changes in task constraints impacted the throwing patterns of children. The study involved 24 children, with an equal number of males and females, aged 5 and 6. The primary task constraints were the orientation of the target (horizontal or vertical hoops) and the size of the ball (diameters of 6 cm or 12 cm). We observed throwing patterns and analyzed kinematic changes in the preferred throws' components. Initially, some children transitioned from using two hands to using one hand, and from underhand to overarm throws, particularly when using the larger balls. However, the preferred pattern for most children was one-hand overarm throwing. The kinematic analysis revealed that the participants adapted their throwing technique based on the size of the ball and the orientation of the hoop. The most significant adjustments occurred in the forearm component in response to changes in the target orientation. Notably, when aiming for a vertical hoop, distinct modifications were observed, including elevating the humerus and pulling the hand backward. These findings support the dynamical systems theory, which explains how movement patterns vary during motor development. The study also discussed the potential benefits of using constraints for skill acquisition in physical education settings.

This study investigated ankle discriminative acuity and performance and measurement consistency for tests undertaken with different joint position exposure times (PETs). Twenty-four participants were tested using a novel Smartphone Proprioception for Ankle Navigation (SPAN) under four PETs, i.e., 0.25s, 0.5s, 0.75s and 1s, delivered in a random sequence, and then re-tested within one week. The results indicated a PET main effect (F = 10.12, p = 0.004, partial ƞ2 = 0.14), and limb preference main effect (F = 5.39, p = 0.03, partial ƞ2 = 0.19), without significant interactions (p > 0.05). Ankle proprioception improved with prolonged PET, with the non-dominant side outperforming the dominant side. A PET of 0.25s showed good to excellent reliability, with intraclass correlation coefficients (ICCs) of 0.897 (95%CI: 0.761, 0.955) and 0.885 (95%CI: 0.736, 0.951), with standard errors of measurements (SEM) between 0.030 and 0.035, and minimum detectable change at 90% (MDC₉₀) between 0.070 and 0.082, compared to poor to moderate reliability at the other three longer PETs (ICCs =0.352-0.736). The findings suggested the prolongation of PET can improve ankle proprioceptive performance but can amplify the inter-occasion variability, likely due to increased cognitive analysis with longer stimulus sampling. SPAN may thus be a cost-effective and accessible apparatus for clinical practice.

Knee osteoarthritis (KOA) is a prevalent and severe condition with versatile effects on human locomotion, including alterations in neuromuscular control. Muscle synergies are understood as functional low-dimensional building blocks within the neuromuscular organization. To examine alterations in muscle synergy patterns during locomotion tasks in the presence of KOA, 40 participants, including 20 with medial KOA (KL-Score ≥ 2), performed level walking, as well as ramp and stair ascent and descent trials at self-selected speeds. Sixteen-Channel bilateral surface electromyography (sEMG) and marker-based motion capture data were collected. Non-negative matrix factorization (NNMF) was applied to the sEMG data for muscle synergy extraction. During level walking and descending conditions, structural changes in muscle synergy composition were observed in the KOA affected limb when compared to the unaffected side and control group. Alterations included fewer, merged synergies with prolonged activation coefficients and a higher percentage of unclassifiable synergies. No major alterations were observed during ascending conditions. No significant differences in gait speed and stride length were observed. These results indicate that muscle synergy composition can be altered in the presence of KOA regardless of age and gait speed, but not during all forms of locomotion.