Journal of Motor Behavior最新文献

Muroi et al. show that individuals with stroke have improved collision avoidance behavior when passing through an aperture while entering from the paretic-side of the body. However, the underlying mechanism remains unknown. We reanalyzed Muroi et al.'s data to reveal how individuals with stroke walk through an aperture by examining changes in walking velocity and behavioral complexity (i.e., sample entropy, an index of (ir)regularity of time series, regarded lower entropy as more regular and less complex) by focusing on the approaching process. The results showed that individuals with stroke reduced their walking velocity and behavioral complexity before passing through the narrow aperture when approaching from the paretic side. We interpreted that the improved obstacle avoidance when penetrating from the paretic side may be due to careful body rotation and adjusting the walking velocity in advance.

Limits of Stability protocols are typically target-oriented, leaving volitional aspects of control unobservable. A novel unconstrained protocol, volitional Limits of Stability (vLOS), shows high test-retest-reliability. We tested if verbal encouragement impacts this protocol. Forty healthy young adults (age 20.1 ± .9 years) performed three trials of vLoS with instructions that were agnostic to strategy or vigor, except trial three included verbal encouragement. Total sway area was used to metric the maximum volitional dynamic sway during each 1-min trial. One-way, repeated-measures ANOVA revealed significant differences (F_(2,117) = 41.56, p < 0.0001, ${\eta }_p^2$ = 0.52) due to encouragement. Specifically, follow-up paired t-tests showed no difference in sway area between the first two trials (p = 0.61), while trial three was much larger than trials one and two (p < 0.0001). Significant, large increases in sway area with verbal encouragement indicate that top-down mechanisms should be considered in theories of postural control. As well, clinical utilization of novel vLOS should be careful with word selection and delivery of protocol instructions.HIGHLIGHTSLimits of Stability balance tests typically include a goal directed instruction and metrics.Dynamic postural sway should be tested in a task affording participant volitional control.A novel volitional Limits of Stability protocol has been developed.Maximal dynamic postural sway responds to motivating instructions.Psychological factors of postural sway control deserve further investigation.

Previous literature suggests that correcting ongoing movements is more effective when using the dominant limb and seeing with the dominant eye. Specifically, individuals are more effective at adjusting their movement to account for an imperceptibly perturbed or changed target location (i.e., online movement correction), when vision is available to the dominant eye. However, less is known if visual-motor functions based on monocular information can undergo short-term neuroplastic changes after a bout of practice, to improve online correction processes. Participants (n = 12) performed pointing movements monocularly and their ability to correct their movement towards an imperceptibly displaced target was assessed. On the first day, the eye associated with smaller correction amplitudes was exclusively trained during acquisition. While correction amplitude was assessed again with both eyes monocularly, only the eye with smaller correction amplitudes in the pre-test showed significant improvement in delayed retention. These results indicate that monocular visuomotor pathways can undergo short-term neuroplastic changes.

Mental fatigue (MF) occurs when a demanding cognitive-task is performed over a long period of time, making it difficult to continue daily tasks and maintain balance. The aim of this investigation was to determine whether the Stroop test induces mental fatigue and to examine its effects on static balance. The study is a quasi-experimental design with pre-post testing. Twenty participants (19-44) were included. Static posturography was used to evaluate balance at baseline following a 25-min relaxation period of rest and in the MFC (mental-fatigue condition) following the induction of MF with the Stroop test. The other measurements were the Multidimensional Fatigue Inventory (MFI), Fatigue Severity Scale (FSS), and Visual Analogue Scale (VAS). The study found that mental fatigue significantly increased at MFC compared to baseline, as indicated by MFI (p=.031) and FSS (p=.007) results with moderate effect sizes (d = 0.52, d = 0.67, respectively). Similarly, the study found a statistically significant increase in mental fatigue as measured by VAS results (p=.000, d = 0.95). However, the study did not find any statistically significant impairment in static balance due to mental fatigue in healthy young subjects. The results suggest that the Stroop test can induce mental fatigue, but it does not impair static balance.

In this study, the relationship between behavioral complexity (sample entropy, SEn) during steady walking and the quickness of subsequent turning performance in older adults. Herein, healthy older and younger adults (n = 12 each) were instructed to walk straight and then turn into an intersection surrounded by four pylons. This walking task was performed under two turning conditions: reactive and pre-planned turning, where the direction of turning was unknown until immediately before turning or was informed beforehand, respectively. For older adults, behavioral complexity was comparable under both conditions, but was higher under reactive than pre-planned turning condition for younger adults. This suggests that older adults cannot adapt their walking patterns in response to turning conditions. Correlation analysis showed that older adults with lower SEn had more difficulty in turning rapidly under reactive turning condition, indicating a relationship between the two variables. Thus, deterioration of the reactive turning performance in older adults is related to stereotyped movements during steady walking.

The objective of the present study was to examine the effects of gender stereotype on the performance and learning of a classical ballet pirouette in 11-year-old boys. Participants in the stereotype threat (ST) group were informed that, in general, boys tend to show worse results when completing the pirouette task in comparison to girls. Participants in the stereotype lift (SL) group were told that girls tend to show worse results in comparison to boys. The control group did not receive stereotype instructions. The results demonstrated worse performance during practice and retention (next day) for the ST group relative to the SL and control groups; the SL and control groups did not differ. The findings indicate that gender stereotype threat can undermine motor performance and learning in boys.