Action observation produces motor resonance in Parkinson's disease

Observation of movement activates the observer's own motor system, influencing the performance of actions and facilitating social interaction. This motor resonance is demonstrated behaviourally through visuomotor priming, whereby response latencies are influenced by the compatibility between an intended action and an observed (task‐irrelevant) action. The impact of movement disorders such as Parkinson's disease (PD) on motor resonance is unclear, as previous studies of visuomotor priming have not separated imitative compatibility (specific to human movement) from general stimulus‐response compatibility effects. We examined visuomotor priming in 23 participants with mild‐to‐moderate PD and 24 healthy older adults, using a task that pitted imitative compatibility against general stimulus‐response compatibility. Participants made a key press after observing a task‐irrelevant moving human finger or rectangle that was either compatible or incompatible with their response. Imitative compatibility effects, rather than general stimulus‐response compatibility effects, were found specifically for the human finger. Moreover, imitative compatibility effects did not differ between groups, indicating intact motor resonance in the PD group. These findings constitute the first unambiguous demonstration of imitative priming in both PD and healthy ageing, and have implications for therapeutic techniques to facilitate action, as well as the understanding of social cognition in PD.     

The influences of tropical climate on imagined walking time

This study investigated the effects of a Tropical Climate (TC) on actual and imagined walking times. Participants had to execute and imagine walking 3 distances with or without a 10-kg weight in either a TC or an Air Conditioning (AC) condition. The motor imagery quality was evaluated by computing the isochrony index. The results revealed that movement times were shorter for imagined walking than for actual walking and increased with the distance of the paths in both cases. By contrast, the effect of the load increased actual walking times for the 10- and 15-meter distances without affecting imagined walking times. Importantly, the isochrony index was negatively affected by the increase in load and distance and the effects of distance were amplified in a TC. These findings showed that the environmental climate in which motor imagery arises can modulate the subject’s ability to build up the temporal characteristics of simulated actions.     

The association of motor information and verbal information: a new perspective on the mechanism of the SPT effect

Current perspectives on the mechanism underlying the Subject Performed Task (SPT) effect have not yet reached a consensus. This study investigated whether the association between motor and verbal information is a key factor that explains the SPT effect. Experiment 1 and 2 tested whether motor and verbal retrieval memory performance were different when the association level was varied. Results showed that when subjects used low association learning materials, memory performance in either motor or verbal retrieval condition was significantly better than performance in the combined retrieval condition. Experiment 3 examined whether the level of association between motor and verbal information affects the SPT effect. Results revealed that the SPT effect disappeared when low association learning materials were used. Our findings imply that the high association level between motor and verbal information enables mutual activation of the two information types, leading to improved memory performance.     

What Does the DAP:IQ Measure?: Drawing Comparisons between Drawing Performance and Developmental Assessments

Human figure drawing tasks such as the Draw-a-Person test have long been used to assess intelligence (F. Goodenough, 1926). The authors investigate the skills tapped by drawing and the risk factors associated with poor drawing. Self-portraits of 345 preschool children were scored by raters trained in using the Draw-a-Person Intellectual Ability test (DAP:IQ) rubric (C. R. Reynolds & J. A. Hickman, 2004). Analyses of children's fine motor, gross motor, social, cognitive, and language skills revealed that only fine motor skill was an independent predictor of DAP:IQ scores. Being a boy and having a low birth weight were associated with lower DAP:IQ scores. These findings suggest that although the DAP:IQ may not be a valid measure of cognitive ability, it may be a useful screening tool for fine motor disturbances in at-risk children, such as boys who were born at low birth weights. Furthermore, researchers who use human figure drawing tasks to measure intelligence should measure fine motor skill in addition to intelligence.     

Motor and Visual-spatial Cognition Development in Primary School-Aged Children in Cameroon and Germany

It was the main goal of this study to investigate the motor and visual-spatial development in primary school-aged children in Cameroon and Germany. Thirty-four children from each country completed a motor test and a mental rotation test. It was found that children in Cameroon showed a better motor ability (better overall gross motor score and also on most single items) than children in Germany did. This can be explained by the early motor stimulation in infancy in Cameroon. Concerning mental rotation performance, Cameroonian children perform below chance level. A positive correlation between the overall motor ability and mental rotation performance could only be analyzed and conducted in the German sample. Therefore, this study emphasizes the need for the development of culture-fair cognitive tests.     

Profiling Movement and Gait Quality Characteristics in Pre-School Children

There is a dearth of suitable metrics capable of objectively quantifying motor competence. Further, objective movement quality characteristics during free play have not been investigated in pre-school children. The aims of this study were to characterize children's free play physical activity and investigate how gait quality characteristics cluster with free play in pre-school children (3–5 years old). Sixty-one children (39 boys; 4.3 ± 0.7 years, 1.04 ± 0.05 m, 17.8 ± 3.2 kg) completed the movement assessment battery for children and took part in free play while wearing an ankle- and hip-mounted accelerometer. Characteristics of movement quality were profiled using a clustering algorithm. Spearman's rho and the Mann-Whitney U tests were used to assess relationships between movement quality characteristics and motor competence classification differences in integrated acceleration and spectral purity, respectively. Significant differences were found between motor competency classifications for spectral purity and integrated acceleration (p < .001). Spectral purity was hierarchically clustered with motor competence and integrated acceleration. Significant positive correlations were found between spectral purity, integrated acceleration and motor competence (p < .001). This is the first study to report spectral purity in pre-school children and the results suggest that the underlying frequency component of movement is clustered with motor competence.     

Dyad Practice Impacts Self-Directed Practice Behaviors and Motor Learning Outcomes in a Contextual Interference Paradigm

We studied dyad practice to determine whether and how alternating practice blocks with a partner impacts self-directed practice scheduling, learning, and perceptions of practice. Participants were assigned to be Partner 1 (P1) or 2 (P2). P1s had a blocked, random, or self-directed schedule, while all P2s self-directed practice of 3, differently-timed keystroke-sequences. P2s showed both own error-dependent practice (switching sequences following better performance) and partner-dependent practice, with the partner's schedule impacting sequence selection and switching frequency. A partner's schedule also impacted learning. Random practice resulted in better timing accuracy than blocked practice for both partners in an immediate and delayed retention test. These data give evidence that self-directed practice behaviors and learning outcomes are modulated by a partner's practice schedule.     

The Influence of an Acute Bout of Whole Body Vibration on Human Postural Control Responses

The use of vibrating platforms has become increasingly available, and popular at sports and rehabilitation institutes. Given the discrepancies in the literature regarding whole body vibration (WBV) and human reflexive responses, the purpose of this study was to examine the acute effects of WBV on postural response latencies, as well as associated electromyography measures of the lower extremities during balance perturbations. Reflexive responses during backward and forward balance perturbations were examined before, after, and 10 min after a bout of WBV. The findings suggest that following an acute bout of whole body vibration, muscle activity of the lower extremities is decreased during a reflexive response to an unexpected perturbation, and may be associated with faster reaction time.     

Targeted Memory Reactivation During Sleep,But Not Wake,Enhances Sensorimotor Skill Performance: A Pilot Study

The benefits of sleep on memory consolidation have been enhanced for declarative and motor sequence learning through replaying classically conditioned auditory stimuli during sleep, known as targeted memory reactivation (TMR). However, it is unknown if TMR can influence performance of a sensorimotor skill, in the absence of the cognitive requirements of sequence learning. Here, young adults performed a nondominant arm throwing task separated by a full night of sleep or a full day of wake, with half of all participants receiving TMR between sessions. Participants who received TMR during sleep demonstrated enhanced sensorimotor performance relative to all other groups. In conclusion, this pilot study indicates that it is feasible to influence sensorimotor skill performance through TMR during sleep and may serve as a future adjunct to physical rehabilitation. Future studies will aim to confirm the present results with a larger sample size as well as investigate the effects of TMR during sleep on older adults both with and without a history of stroke.