Relationships between coordination,active drag and propelling efficiency in crawl

This study examines the relationships between the index of coordination (IdC) and active drag (D) assuming that at constant average speed, average drag equals average propulsion. The relationship between IdC and propulsive efficiency (e_p) was also investigated at maximal speed. Twenty national swimmers completed two incremental speed tests swimming front crawl with arms only in free condition and using a measurement of active drag system. Each test was composed of eight 25-m bouts from 60% to 100% of maximal intensity whereby each lap was swum at constant speed. Different regression models were tested to analyse IdC–D relationship. Correlation between IdC and e_p was calculated. IdC was linked to D by linear regression (IdC = 0.246 · D − 27.06; R² = 0.88, P < .05); swimmers switched from catch-up to superposition coordination mode at a speed of ∼1.55 m s⁻¹ where average D is ∼110 N. No correlation between IdC and e_p at maximal speed was found. The intra-individual analysis revealed that coordination plays an important role in scaling propulsive forces with higher speed levels such that these are adapted to aquatic resistance. Inter-individual analysis showed that high IdC did not relate to a high e_p suggesting an individual optimization of force and power generation is at play to reach high speeds.     

Exercise can improve physical self perceptions in adolescents with low motor competence

Adolescents with low motor competence have diminished perceptions of their physical self and tend to avoid physical activities. This study examined the outcomes of an exercise intervention that focused on improving aerobic fitness, strength, and self-perceptions in the physical domain in adolescents with poor motor coordination. The sample included 35 adolescents with low motor competence, comprising boys (n = 25) and girls (n = 10) ranging in age from 13 to 17 years, who attended two sessions per week in the 13 week exercise intervention study (AMP it up). Physical self-perceptions were measured before and after the intervention using the Physical Self Perception Profile and Perceived Importance Profile. Significant improvements in perceived Physical Condition, Attractive Body and Physical Strength sub domain scores were identified between pre and post-test. Adjusting for age, gender, BMI and attendance, regression analyses revealed that Attractive Body was the strongest predictor of Physical Self Worth at pre-test, joined by Physical Condition at post-test. This exercise intervention had a positive impact on adolescent physical self-perceptions, in particular males, with improvements in those sub domains specifically related to the exercise program. Changes in specific aspects of Physical Self Worth can be facilitated by exercise interventions, after a relatively short period of time, in adolescents with poor motor coordination.     

A crossover randomised and controlled trial of the impact of active video games on motor coordination and perceptions of physical ability in children at risk of Developmental Coordination Disorder

BackgroundImpaired motor development can significantly affect a child’s life and may result in an increased risk of a range of physical and psychological disorders. Active video game (AVG) interventions have been demonstrated to enhance motor skills in children with Developmental Coordination Disorder (DCD); however a home-based intervention has not been assessed.ObjectivesThe primary aim of this study was to compare the changes in motor coordination between a 16 week period of AVG use, with 16 weeks of normal activities (NAG). The secondary aim was to compare the child and parent perceptions of their physical performance between the AVG and NAG conditions.MethodsTwenty-one 9–12 year olds (10 males) were confirmed to be at risk of DCD (⩽16th percentile Movement Assessment Battery for Children-2nd edition (MABC-2) and ⩽15th percentile Developmental Coordination Disorder Questionnaire (DCDQ)) and participated in this crossover randomised and controlled trial. Data was collected at study entry, after the first 16 week condition and following the final 16 week condition, including; (1) the MABC-2, (2) three-dimensional motion analysis of single leg balance and finger–nose tasks, and (3) parent perception of physical skills. Participant perception of physical skills was collected only after the first and second conditions.ResultsThere was no significant difference between AVG and NAG for any of the primary variables including the MABC-2, balance centre-of-mass path distance and finger–nose path distance. There was no significant intervention effect for secondary measures of motor coordination; however the children perceived their motor skills to be significantly enhanced as a result of the AVG intervention in comparison to the period of no intervention.ConclusionA 16 week home based AVG intervention did not enhance motor skills in children with DCD, although they perceived their physical skills to be significantly improved.Trial Registration: Australia and New Zealand Clinical trials Registry (ACTRN 12611000400965).     

The role of eye movements in motor sequence learning

An experiment that utilized a 16-element movement sequence was designed to determine the impact of eye movements on sequence learning. The participants were randomly assigned to two experimental groups: a group that was permitted to use eye movements (FREE) and a second group (FIX) that was instructed to fixate on a marker during acquisition (ACQ). A retention test (RET) was designed to provide a measure of learning, and two transfer tests were designed to determine the extent to which eye movements influenced sequence learning. The results demonstrated that both groups decreased the response time to produce the sequence, but the participants in the FREE group performed the sequence more quickly than participants of the FIX group during the ACQ, RET and the two transfer tests. Furthermore, continuous visual control of response execution was reduced over the course of learning. The results of the transfer tests indicated that oculomotor information regarding the sequence can be stored in memory and enhances response production.     

Quantitative assessment of drawing tests in children with dyslexia and dysgraphia

Drawing tests in children diagnosed with dyslexia and dysgraphia were quantitatively compared. Fourteen children with dysgraphia, 19 with dyslexia and 13 normally developing were asked to copy 3 figures: a circle, a square and a cross. An optoelectronic system allowed the acquisition of the drawing track in three-dimensions. The participants’ head position and upper limb movements were measured as well. A set of parameters including movement duration, velocity, length of the trace, Range of Motion of the upper limb, was computed and compared among the 3 groups. Children with dyslexia traced the circle faster than the other groups. In the cross test, dyslexic participants showed a reduced execution time and increased velocity while drawing the horizontal line. Children with dyslexia were also faster in drawing certain sides of square with respect to the other groups.     

Individual differences in higher-level cognitive abilities do not predict overconfidence in complex task performance

Even when people perform tasks poorly, they often report unrealistically positive estimates of their own abilities in these situations. To better understand the origins of such overconfidence, we investigated whether it could be predicted by individual differences in working memory, attentional control, and self-reported trait impulsivity. Overconfidence was estimated by contrasting objective and subjective measures of situation awareness (the ability to perceive and understand task-relevant information in the environment), acquired during a challenging air traffic control simulation. We found no significant relationships between overconfidence and either working memory or attentional control. However, increased impulsivity significantly predicted greater overconfidence. In addition, overall levels of overconfidence were lower in our complex task than in previous studies that used less-complex lab-based tasks. Our results suggest that overconfidence may not be linked to high-level cognitive abilities, but that dynamic tasks with frequent opportunities for performance feedback may reduce misconceptions about personal performance.     

The role of response readiness in subliminal visuomotor processes

The present study aims to examine the impact of response readiness on visuomotor processes triggered by subliminal stimuli using a mixed paradigm involving the masked prime paradigm and a foreperiod paradigm. Experiment 1 ensured that response readiness was successfully manipulated in the mixed paradigm. Importantly, Experiment 2 found that the negative compatibility effect (NCE; a behavioral indicator of subliminal visuomotor processes) disappeared and that response time lost its power to modulate the compatibility effect (CE) with reduced response readiness (due to temporal uncertainty). These results of CEs both independent of response latency and across different levels of response latency indicate that response readiness is a prerequisite for obtaining the NCE. The findings suggest that automatic processing of subliminal stimuli is susceptible to top-down control for reducing the interference of irrelevant information, which ensures a high degree of adaptability and flexibility of our cognitive system in interactions with the changing environment.     

Sleep deprivation impairs object recognition in mice

Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in an object recognition task in OF1 mice subjected to 6h SD either immediately after the acquisition phase (0-6 SD) or 6h later (7-12 SD), and in corresponding undisturbed controls. Motor activity was continuously recorded with infrared sensors. All groups explored two familiar, previously encountered objects to a similar extent, both at the end of the acquisition phase and 24h later during the test phase, indicating intact familiarity detection. During the test phase 0-6 SD mice failed to discriminate between the single novel and the two familiar objects. In contrast, the 7-12 SD group and the two control groups explored the novel object significantly longer than the two familiar objects. Plasma corticosterone levels determined after SD did not differ from time-matched undisturbed controls, but were significantly below the level measured after learning alone. ACTH did not differ between the groups. Therefore, it is unlikely that stress contributed to the memory impairment. We conclude that the loss of sleep and the activities the mice engaged in during the SD, impaired recognition memory retrieval, when they occurred immediately after acquisition. The delayed SD enabled memory consolidation during the 6h when the mice were allowed to sleep, and had no detrimental effect on memory. Neither SD schedule impaired object familiarity processing, suggesting that only specific cognitive abilities were sensitive to the intervention. Sleep may either actively promote memory formation, or alternatively, sleep may provide optimal conditions of non-interference for consolidation.     

General self-concept and life satisfaction for boys with differing levels of physical coordination: the role of goal orientations and leisure participation

Participation in leisure-time activities, self-concept perceptions and individual dispositional goal orientations were examined as mediators of relationships between physical coordination and self-evaluations of life satisfaction and general self-concept for 173 boys aged 10-13 years. Participants completed seven-day activity diaries and 12-month retrospective recall questionnaires recording participation in leisure-time activities. Self-report measures of self-concept, global life satisfaction and dispositional goal orientations were also completed. Results showed that boys with moderate to severe physical coordination difficulties had significantly lower self-concept perceptions of physical ability and appearance, peer and parent relations and general self-concept, as well as lower life satisfaction than boys with medium to high levels of physical coordination. The relationships between boys' physical coordination and their self-perceptions of life satisfaction and general self-concept were significantly influenced by individual self-concept appraisals of physical ability and appearance, peer and parent relations. Adopting task-oriented goals was found to positively change the relationship between physical coordination and both general self-concept and life satisfaction. Team sport participation positively mediated the relationship between physical coordination and life satisfaction. The potential for team sport participation and adoption of task-oriented goals to influence life satisfaction for boys with differing levels of physical coordination was discussed.