Journal of Motor Behavior最新文献

The benefits of allowing learners to control when to receive knowledge of results (KR) compared to a yoked group has been recently challenged and postulated to be mild at best. A potential explanation for such dissident findings is that individuals differentially utilize the autonomy provided by the self-controlled condition, which, in its turn, affects the outcomes. Therefore, the present study investigated the effects of self-controlled KR on motor learning focusing on the frequency of KR requests when performing an anticipatory timing task. Self-controlled groups were created based on participants' KR frequency of request (High, Medium, and Low referring to fifth, third, and first quintile) and, then, Yoked groups were created self-control condition pairing the KR request of the Self-controlled groups. We also measured self-efficacy and processing time as means to verify potential correlates. The results supported the expected interaction. While no difference between self-controlled and yoked groups were found for low frequencies of KR, a moderate amount of KR request was related to better results for the self-controlled group. Nonetheless, the opposite trend was observed for high frequencies of KR; the yoked group was superior to the self-controlled group. The results of this study allow us to conclude that the choices made, and not just the possibility of choosing, seem to define the benefits of KR self-control in motor learning.

This study aimed to examine the influence of different observational angles in video self-modeling on task acquisition and retention. We randomly assigned 42 Japanese university students to three camera-angle groups, i.e., a front-angle, a rear-angle, and a control group. The participants performed a 3 × 6 × 3 cup-stacking task with three sequential laps. The front- and rear-angle groups viewed video self-modeling created from previously self-chosen videos. The retention phase was conducted 1 week after the acquisition phase. The rear-angle group demonstrated the fastest movement times in the acquisition phase. Our findings indicate that viewing learner-chosen video self-modeling from a rear angle enhances motor skill acquisition but does not contribute to motor skill learning.

This study aims to identify differences between participants with and without stroke regarding the ipsilesional and contralesional lower limbs kinematics, kinetics, muscle activity and their variability during double support phase of gait. Eleven post-stroke and thirteen healthy participants performed 10 gait trials at a self-selected speed while being monitored by an optoelectronic motion capture system, two force plates and an electromyographic system. The following outcomes were evaluated during the double support: the time and the joint position; the external mechanical work on the centre of mass; and the relative electromyographic activity. Both, contralesional/ipsilesional and dominant/non-dominant of participants with and without stroke, respectively, were evaluated during double support phase of gait in trailing or leading positions. The average value of each parameter and the coefficient of variation of the 10 trials were analysed. Post-stroke participants present bilateral decreased mechanical work on the centre of mass and increased variability, decreased contralesional knee and ankle flexion in trailing position, increased ipsilesional knee flexion in leading position and increased variability. Increased relative muscle activity was observed in post-stroke participants with decreased variability. Mechanical work on the centre of mass seems to be the most relevant parameter to identify interlimb coordination impairments in post-stroke subjects.

The association between low back pain and lumbar spine local dynamic stability (LDS) appears to be modulated by if and how someone catastrophizes about pain, suggesting that the cognitive perceptions of pain may influence an individual's ability to control lumbar spine motion. Previous work also demonstrates that directing cognitive resources and attentional focus can influence movement performance. Therefore, we aimed to examine whether distracting attentional focus would influence lumbar spine LDS during repetitive flexion-extension movements. Sixteen participants performed repetitive spine flexion-extension movements under two baseline conditions (pre- and post-), and while attentional focus was distracted by either an external sensory stimulus or a cognitive-motor dual-task, both targeted at the hands. Lumbar spine LDS was examined over 30 continuous movement repetitions using maximum Lyapunov exponents. In comparison to both Baseline and Post-Baseline trials, the perceived mental workload was significantly elevated during the cognitive-motor dual-task trial but not the external sensory stimulus trial. The only statistically significant effect on LDS occurred in the Post-Baseline trial, where LDS was higher than in the cognitive-motor dual-task. In combination with previous work, these findings suggest that distracting attentional focus during repetitive lumbar spine flexion-extension movements does not have a negative influence on lumbar spine LDS.

Attention Deficit Hyperactivity Disorder (ADHD) is characterized by inappropriate levels of activity, impulsivity, and inattention. Developmental Coordination Disorder (DCD) is a condition involving challenges in acquiring and executing motor skills. This cross-sectional study aimed to distinguish motor symptoms between ADHD and ADHD/DCD. A total of 283 children from two elementary schools underwent screening, leading to the identification of 27 children with ADHD. The assessment encompassed the Swanson, Nolan, and Pelham-IV Questionnaire (SNAP-IV), the Movement Assessment Battery for Children (MABC-2), and the Motor Development Scale (MDS). The groups consisted of ADHD (14) and ADHD/DCD (13). Statistical analysis revealed significant differences in general motor age means between groups (p = 0.016), indicating inferior performance in the ADHD/DCD group. The coexistence of DCD significantly influenced the motor performance of children with ADHD, particularly in fine motor skills (p = 0.018) and balance (p = 0.033). Both groups exhibited mild to moderate risk of motor development delay. It is suggested that ADHD is associated with motor problems, even when DCD is not co-occurring. Specific domain-based analysis could demonstrate how the co-occurrence with DCD affects the motor performance of children with ADHD, with statistically significant differences observed in fine motor skills and balance.

This study assessed the impact of integrated neuromuscular training (INT) on athletes' jumping performance and lower limb injury prevention. A thorough search across multiple databases, including PubMed, Web of Science, Science Direct, and the Cochrane Library, identified a sample of 19,805 athletes aged between 8.5 and 27.7 years. Results showed that INT led to a significant improvement in jumping ability (SMD = 0.45, 95% CI 0.30-0.60, P = 0.000) and a reduction in lower limb injuries (SMD = 0.68, 95% CI 0.62-0.74, P = 0.000). The most effective interventions lasted at least 25 minutes, conducted 2-5 times per week, for a minimum of 9 weeks. This approach was particularly beneficial for children and adolescents, as it enhanced their countermovement jump (CMJ) ability and helped in the prevention of injuries.

Gait training with rhythmic auditory cues contains motor learning mechanisms that are weighted more explicitly than implicitly. However, various clinical populations may benefit from a shift to gait training with greater implicit motor learning mechanisms. To investigate the ability to incorporate more implicit-weighted motor learning processes during rhythmic auditory cueing, we attempted to induce error-based recalibration using a subtly varying metronome cue for naïve unimpaired young adults. We assessed the extent of implicit and explicit retention after both an isochronous metronome and subtly varying metronome frequency during treadmill and overground walking. Despite 90% of participants remaining unaware of the changing metronome frequency, participants adjusted their cadence and step length to the subtly changing metronome, both on a treadmill and overground (p < 0.05). However, despite evidence of both implicit and explicit processes involved with each metronome (i.e., isochronous and varying), there were no between-condition differences in implicit or explicit retention for cadence, step length, or gait speed, and thus no increased implicit learning advantage with the addition of error-based recalibration for young, unimpaired adults.

Intracortical Brain-Computer Interfaces (iBCI) use single-unit activity (SUA), multiunit activity (MUA) and local field potentials (LFP) to control neuroprosthetic devices. SUA and MUA are usually extracted from the bandpassed recording through amplitude thresholding, while subthreshold data are ignored. Here, we show that subthreshold data can actually be decoded to determine behavioral variables with test set accuracy of up to 100%. Although the utility of SUA, MUA and LFP for decoding behavioral variables has been explored previously, this study investigates the utility of spike-band subthreshold activity exclusively. We provide evidence suggesting that this activity can be used to keep decoding performance at acceptable levels even when SUA quality is reduced over time. To the best of our knowledge, the signals that we derive from the subthreshold activity may be the weakest neural signals that have ever been extracted from extracellular neural recordings, while still being decodable with test set accuracy of up to 100%. These results are relevant for the development of fully data-driven and automated methods for amplitude thresholding spike-band extracellular neural recordings in iBCIs containing thousands of electrodes.

The current study aimed to evaluate the effects of action observation on the walking ability and oscillatory brain activity of chronic stroke patients. Fourteen chronic stroke patients were allocated randomly to the action observation (AO) or sham observation (SO) groups. Both groups received 12 sessions of intervention. Each session composed of 12 min of observational training, which depicted exercises for the experimental group but nature pictures for the sham group and 40 min of occupational therapy, which was the same for the both groups. Walking ability was assessed by a motion analysis system and brain activity was monitored using quantitative electroencephalography (QEEG) before and after the intervention. Brain asymmetry at alpha frequency, the percentage of stance phase, and step length showed significant changes in the AO group. Only the change in global alpha power was significantly correlated with the change in velocity after the intervention in AO group. Despite more improvements in walking and brain activity of patients in the AO group, our study failed to show significant correlations between the brain activity changes and functional improvements after the intervention, which might be mainly due to the small sample size in our study. Trial registration: IRCT20181014041333N1.

This study examined the attentional demands of movement sequence representations at different temporal points after single- or dual-task practice. The visual-spatial representation encodes the movement based on visual-spatial coordinates such as the target locations. The motor representation encodes the movement in motor coordinates including joint angles and muscle activation patterns. Participants were randomly assigned to a single-task or dual-task practice group. Following acquisition, participants performed two retention tests and inter-manual transfer tests, both under dual-task and single-task. The transfer tests consisted of a mirror and non-mirror test and examined motor and visual-spatial representation development. The main finding is that attentional demands of the sequence representations were not affected by the practice condition. However, movement initiation requires more attention than the end of the movement in both representations.