Modeling effects of risk and social distance on vaccination choice

Despite vaccines' consistently demonstrated effectiveness, vaccination rates remain suboptimal due to vaccine refusal. Low vaccination rates are particularly problematic for individuals who cannot be vaccinated for medical reasons and thus must rely on herd immunity (i.e., protection of vulnerable individuals due to the high rate of vaccination of other—often socially distant—individuals). The current study uses a novel decision‐making task to examine how three variables impacted participants' highest acceptable probability of side effects to their children: 1) the severity of the side effects their children experience, 2) the social distance to the beneficiary of the vaccination, and 3) the probability that the vaccine will prevent disease for that designated beneficiary. Participants' willingness to risk potential side effects of vaccination systematically decreased as the 1) effectiveness of the vaccination decreased, 2) the beneficiary of the vaccination became more socially distant, and 3) the severity of side effects increased. These data were well‐described by behavioral economic models used to examine the discounting of other health behavior.     

Motor imagery ability and internal representation of movement in children with probable developmental coordination disorder

It has been hypothesised that deficits in the functioning of the mirror neuron system (MNS) and internal modelling may contribute to the motor impairments associated with DCD. These processes can be explored behaviourally through motor imagery paradigms. Motor imagery proficiency of children with and without probable DCD (pDCD) was examined using a complex hand rotation task to explore whether motor imagery strategies could be used during more complex tasks. Forty-four boys aged 7–13 years participated, 22 with pDCD (mean = 9.90 years ± 1.57) and 22 controls (mean = 9.68 years ± 1.53). Participants completed the task twice: with and without motor imagery instructions. Stimuli were presented in two rotational axes – palm/back, and eight 45° rotational steps. Both groups showed evidence of following the biomechanical and postural constraints of actual movements. Responses of children with pDCD were slower and less accurate than controls, with group differences increasing alongside task complexity. A greater impact of biomechanical constraints for accuracy was observed in the DCD group. The response characteristics of children with pDCD likely reflects a reduced capacity to mentally manipulate a body schema and reduced visuo-motor processing capabilities. Behaviourally, these processes are linked to MNS and internal modelling function, suggesting deficits in these systems may contribute to the movement difficulties characteristic of DCD.     

Reducing the risk of bias in health behaviour change trials: Improving trial design,reporting or bias assessment criteria? A review and case study

Objective: It has been suggested that randomised controlled trials (RCTs) of health behaviour change (HBC) interventions are less rigorously designed than – for example– drug trials. This study presents an approach to clarifying whether this is due to poor trial design, incomplete trial reporting and/or the inappropriateness of commonly applied risk of bias assessment criteria.

Design: First, a framework of key sources of bias and common strategies for reducing bias risk is developed based on a literature review. Second, we describe the design of a multi-site RCT evaluating the cost-effectiveness of an HIV-treatment adherence intervention (case study). The choices made by the multidisciplinary team trying to minimise the risk of bias are compared against the risk of bias framework.

Main outcome measures: Implementation of common strategies for reducing the risk of bias in the case study; alternative or additional strategies applied; a justification for each deviation from the risk of bias framework.

Results: Most of the common strategies for reducing the risk of bias could be implemented. Alternative strategies were developed for minimising the risk of performance bias and contamination. Several additional, domain-specific risk of bias strategies were implemented.

Conclusions: The literature provides useful guidance for reducing the risk of bias in HBC trials. Yet, the case study suggests that HBC trial designers may face specific challenges that require alternative/additional measures for reducing the risk of bias. Using the risk of bias justification table (RATIONALE) could lead to better-designed HBC trials, more comprehensive trial reports and the data necessary for evaluating the appropriateness of commonly applied risk of bias assessment criteria to HBC trials.     

Student Service Members/Veterans’ Mental Health: Who Is at a Greater Risk for Posttraumatic Stress Symptoms on College Campuses?

Using a cross-sectional design, this study surveyed 144 students on campus who are service members and veterans to determine whether posttraumatic stress (PTS) symptoms are significantly correlated with demographic factors (e.g., age, race and marital status), risk factors (e.g., military branch and combat exposure), and resources (e.g., social support and religiosity). The results confirm previous findings on correlates of PTS symptoms, provide new information about service members on campus that are at a greater risk for PTS and highlight resources that are associated with reduced PTS symptoms. These findings not only give institutions of higher learning insight into identifying specific demographics that are at a greater risk for PTS symptoms on college campuses, but also point to ways of supporting student service members/veterans by accurately targeting existing resources to the most affected populations.     

The impact of concurrent visual feedback on coding of on-line and pre-planned movement sequences

The purpose of this study was to determine the extent to which participants could effectively switch from on-line (OL) to pre-planned (PP) control (or vice versa) depending on previous practice conditions and whether concurrent visual feedback was available during transfer testing. The task was to reproduce a 2000 ms spatial–temporal pattern of a sequence of elbow flexions and extensions. Participants were randomly assigned to one of two practice conditions termed OL or PP. In the OL condition the criterion waveform and the cursor were provided during movement production while this information was withheld during movement production for the PP condition. A retention test and two effector transfer tests were administered to half of the participants in each acquisition conditions under OL conditions and the other half under PP conditions. The mirror effector transfer test required the same pattern of muscle activation and limb joint angles as required during acquisition. The non-mirror transfer test required movements to the same visual–spatial locations as experienced during acquisition. The results indicated that when visual information was available during the transfer tests performers could switch from PP to OL. When visual information was withdrawn, they shifted from the OL to the PP-control mode. This finding suggests that performers adopt a mode of control consistent with the feedback conditions provided during testing.     

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.