Cognitive Bias for the Distribution of Ball Landing Positions in Amateur Tennis Players (Cognitive Bias for the Motor Variance in Tennis)

This study aimed to investigate whether the isotropy bias (estimating one's own motor variance as an approximately circular distribution rather than a vertically elongated distribution) arises in tennis players for the estimation of the two-dimensional variance for forehand strokes in tennis (Experiment 1), as well as the process underlying the isotropy bias (Experiment 2). In Experiment 1, 31 tennis players were asked to estimate prospectively their distribution of ball landing positions. They were then instructed to hit 50 forehand strokes. We compared the eccentricity of the ellipse calculated from estimated and observed landing positions. Eccentricity was significantly smaller in the estimated ellipse than in the observed ellipse. We assumed that the isotropy bias for the estimated ellipse comes from the process of variance estimation. In Experiment 2, nine participants estimated the 95% confidence interval of 300 dots. Eccentricity was significantly smaller in their estimated ellipses than it was in the ellipses for the dots, though the magnitude of bias decreased for the estimation of dots. These results suggest that the isotropy bias in tennis ball landing position includes the bias of recognizing landing position and the bias of estimating the ellipse confidence interval from the recognized landing position.     

Potential negative consequences of mindfulness in the moral domain

Mindfulness is a state of paying conscious and nonjudgmental attention to present-moment experiences. Previous research relates this state to more effective emotion regulation and less emotion reactivity. We therefore hypothesized an attenuating effect of a mindfulness exercise on moral reactions that usually results from a bad conscience when having caused harm. Across five studies, we experimentally induced mindfulness via a short breathing exercise and then assessed harm-based moral reactions. As hypothesized, participants in the mindfulness (vs. control) exercise condition showed (i) attenuated repair intentions after having read a scenario in which participants caused harm to a friend (Study 3) and (ii) attenuated intentions to change harm-causing eating habits (Study 4). Results of Studies 1, 2 and 5 did not provide evidence for our hypothesis. A following meta-analysis across all five studies yielded an overall significant effect of mindfulness in the harm-condition, providing preliminary evidence for a potential downside to mindfulness.     

Training of 7-month-old infants’ manual object exploration skills: Effects of active and observational experience

In the present study, a fine motor training was developed and evaluated in which infants were trained to manually explore objects in an advanced manner. Fifty 7-month-old infants were randomly assigned to three different training conditions: (1) to an active manual exploration training, in which they learned to explore objects efficiently, (2) to an observational manual exploration training, in which they observed how an adult performed sophisticated actions on objects, or (3) to a control group receiving no training. The results impressively indicate that infants with a low level of object exploration skill prior to the training showed the most training effects as compared to infants with proficient object exploratory actions. Interestingly, this differential training effect was true for both the active and observational training, highlighting the role of social learning in infancy. Importantly, our study shows for the first time the impact of normal individual variation in infants’ manual object exploration skills on the effects of a fine motor training.     

Relationships among motor skill,perceived self-competence,fitness, and physical activity in young adults

PurposeThis large-scale, exploratory study sought to examine the associations between motor skill proficiency (MSP), perceived self-competence (PC), physical fitness (PF), and self-reported physical activity (PA) to assess the assumption that relationships among these variables found in childhood and adolescence persist into young-adulthood. Specifically, predictors of PF and PA were assessed. Additionally, the contributions body mass index (BMI) and gender made to these relationships, as well as that of process- versus product-oriented motor skills data, were studied. Finally, how these relationships differed by gender was explored.MethodsParticipants’ (n = 448) MSP was assessed using select measures from the TGMD-2 and the BOT-2, while PF was evaluated using the FitnessGram. Participants also completed surveys to assess PC (SPPCS), PA (past-week MAQ), and demographic information. Height and weight were collected to calculate BMI.ResultsModels predicting physical fitness had good fit to the observed data, with perceived athletic competence, locomotor skill, upper-limb coordination, BMI, and gender accounting for about 75% (R² = 0.748) of aerobic PF variance and about 48% (R² = 0.476) of variance in push-up performances. About 18% (R² = 0.178) of variance in curl-up performances was predicted by perceived athletic competence, locomotor skill, upper-limb coordination, and PA. The PA model demonstrated weaker predictive power, with only about 10% (R² = 0.097) of variance explained. When considering male and female models separately, female models demonstrated better fit when predicting all PF and PA outcome variables. BMI and gender operated as significant predictors to differing degrees across the various models.ConclusionsThere is compelling evidence to believe relationships found among MSP, PC, PF, and PA in childhood and adolescence also exist in early adulthood. However, differences in the roles of gender and physical fitness versus physical activity are likely to exist.     

Anticipating ankle inversion perturbations during a single-leg drop landing alters ankle joint and impact kinetics

Anticipatory responses to inversion perturbations can prevent an accurate assessment of lateral ankle sprain mechanics when using injury simulations. Despite recent evidence of the anticipatory motor control strategies utilized during inversion perturbations, kinetic compensations during anticipated inversion perturbations are currently unknown. The purpose of this investigation was to examine the influence of anticipation to an inversion perturbation during a single-leg drop landing on ankle joint and impact kinetics. Fifteen young adults with no lateral ankle sprain history completed unanticipated and anticipated single-leg drop landings onto a 25° laterally inclined platform from a height of 30 cm. One-dimensional statistical parametric mapping (SPM) was used to analyze net ankle moments and ground reaction forces (GRF) during the first 150 ms post-landing, while peak GRFs, time to peak GRF, peak and average loading rates were compared using a dependent samples t-test (p ≤ 0.05). Results from the SPM analysis revealed significantly greater plantar flexion moment from 58 to 83 ms post-landing (p = 0.004; d = 0.64–0.77), inversion moment from 89 to 91 ms post-landing (p = 0.050; d = 0.58–0.60), and medial GRF from 62 to 97 ms post-landing (p < 0.001; d = 1.00–2.39) during the unanticipated landing condition. Moreover, significantly greater peak plantarflexion (p < 0.001; d = 1.10) and peak inversion moment (p = 0.007; d = 0.94), as well as greater peak (p = 0.002; d = 1.03) and average (p = 0.042; d = 0.66) medial loading rates, were found during the unanticipated landing condition. Our findings suggest alterations to ankle joint and impact kinetics occur during a single-leg drop landing when inversion perturbations are anticipated. Researchers and practitioners using drop-landings onto a tilted surface to assess lateral ankle sprain injury risk should consider implementing protocols that mitigate anticipatory responses.     

Intervention,stimulus control,and generalization effects of response interruption and redirection on motor stereotypy

This study evaluated the effects of response interruption and redirection (RIRD) on motor stereotypy (hand and body movements) in a child with neurodevelopmental disorders. We also assessed whether a stimulus paired with RIRD could acquire inhibitory control when tested during nonintervention conditions. Compared with baseline phases in a reversal design, RIRD decreased both hand and motor stereotypies, and there was evidence of stimulus control. Extending RIRD to a second setting was also effective. The care providers responsible for intervention implemented RIRD with fidelity, and they rated the procedure positively. Clinical and research implications from these findings are discussed.     

Movement segmentation and visual perturbation increase developmental differences in motor control and learning

We examined the developmental differences in motor control and learning of a two‐segment movement. One hundred and five participants (53 female) were divided into three age groups (7–8 years, 9–10 years and 19–27 years). They performed a two‐segment movement task in four conditions (full vision, fully disturbed vision, disturbed vision in the first movement segment and disturbed vision in the second movement segment). The results for movement accuracy and overall movement time show that children, especially younger children, are more susceptible to visual perturbations than adults. The adults’ movement time in one of the movement segments could be increased by disturbing the vision of the other movement segment. The children's movement time for the second movement segment increased when their vision of the first movement segment was disturbed. Disturbing the vision of the first movement segment decreased the percentage of central control of the second movement in younger children, but not in the other two age groups. The children's normalized jerk was more easily increased by visual perturbations. The children showed greater improvement after practice in the conditions of partial vision disturbance. As the participants’ age increased, practice tended to improve their feedforward motor control rather than their feedback motor control. These results suggest that children's central movement control improves with age and practice. We discuss the theoretical implications and practical significance of the differential effects of visual perturbation and movement segmentation upon motor control and learning from a developmental viewpoint.     

Impaired sequential and partially compensated probabilistic skill learning in Parkinson's disease

The striatal dopaminergic dysfunction in Parkinson's disease (PD) has been associated with deficits in skill learning in numerous studies, but some of the findings remain controversial. Our aim was to explore the generality of the learning deficit using two widely reported skill learning tasks in the same group of Parkinson's patients. Thirty-four patients with PD (mean age: 62.83 years, SD: 7.67) were compared to age-matched healthy adults. Two tasks were employed: the Serial Reaction Time Task (SRT), testing the learning of motor sequences, and the Weather Prediction (WP) task, testing non-sequential probabilistic category learning. On the SRT task, patients with PD showed no significant evidence for sequence learning. These results support and also extend previous findings, suggesting that motor skill learning is vulnerable in PD. On the WP task, the PD group showed the same amount of learning as controls, but they exploited qualitatively different strategies in predicting the target categories. While controls typically combined probabilities from multiple predicting cues, patients with PD instead focused on individual cues. We also found moderate to high correlations between the different measures of skill learning. These findings support our hypothesis that skill learning is generally impaired in PD, and can in some cases be compensated by relying on alternative learning strategies.     

Is sense of coherence a mediator or moderator of relationships between violence at work and stress reactions?

The relationships between exposure to violence at work, sense of coherence, and stress reactions were analysed in a large sample of the Danish workforce. The results showed that employees subjected to violence have a weaker sense of coherence than the rest of the respondents. Sense of coherence acted as a mediator and not as a moderator of relationships between exposure to violence and psychological, psychosomatic and cognitive stress reactions. The stability of the sense of coherence construct is discussed. With respect to the relation between sense of coherence and violence, preventative measures at the individual and organizational level are suggested.