Sit-to-stand movement in children: A longitudinal study based on kinematics data

Although the ability to stand from a seated posture is relevant for clinical practice, there are few studies investigating the process of acquisition and refinement of the motor components involved in sit-to-stand movement (STS) in children. Therefore, this longitudinal study aims to describe kinematic characteristics of the STS movement in children from 12 to 18 months, and also to investigate the relationship between changes in STS movement and childrens’ daily-life mobility. Ten healthy children were evaluated at 12,13,14,15 and 18 months of age. A motion analysis system was used to measure total duration of STS movement and angular movements of each joint, and frequencies of successful and unsupported STS were obtained. The Pediatric Evaluation of Disability Inventory was used to assess childrens’ daily-life mobility. Results showed that children tend to increase the frequency of successful trials over the months by reducing the total duration and decreasing peak ankle dorsiflexion and trunk flexion during STS. Children also started to stand up from chair with decreased trunk flexion angle among ages. At the end of the STS, we observed decreases in trunk flexion and knee flexion over age. Furthermore, kinematic characteristics that reflect improvements in STS movement are related to better performance of functional skills and decreased level of assistance provided by the caregiver in daily-life mobility of younger children. However, the strength of these associations decreases from 14 months of age onwards.     

A behavioural experiment in virtual reality to verify the role of action function in space coding

Neurophysiological data indicate that the reachable peripersonal space and the unreachable extrapersonal space are represented in segregated parietofrontal circuits and that when the unreachable space becomes reachable because of tool use, it is automatically coded by the network selective for peripersonal space. Here we directly tested the role of action's consequences in space coding. Thirty-eight participants bisected lines at either a reachable distance (60 cm) or unreachable distance (120 cm) using either a laser pointer or laser cutter. The laser cutter but not the laser pointer had an action consequence; the line broke into two pieces. The results showed that distance moderated the effect of action. At an unreachable distance, the mean bisection point was closer to the centre when participants used the laser cutter compared to when they used the laser pointer. There were no differences at a reachable distance (60 cm). This result suggests that the space in which the individual may determine a physical consequence is categorized as peripersonal space, independently from its actual distance from the individual's body.     

Book Review

Experienced military air traffic controllers (25 respondents, males = 15, females = 10, years of experience = less than one year = 5 respondents, more than one year but less than three years = 11 respondents and more than three years = 9 respondents) participated in this study to determine whether self-directed team learning exists within their air traffic control teams and to understand the impact of self-directed team learning on the air traffic control work environment. Data on self-directed team learning and learning approaches were collected using a Self-directed Team Learning Questionnaire (SDTLQ) and a Learning Approaches Questionnaire (LAQ). These data were analysed using an inductive reasoning mode for qualitative data analysis and quantitative data analysis followed a supporting deductive reasoning mode. Triangulation as a technique was used to determine whether multiple sources of data agreed and to obtain better, cross-checked insights (Burgess, 1985). Results revealed that these air traffic controllers and air traffic control teams investigated in the study do indeed function within self-directed working, training and learning environments. The quality of team performance was influenced by self-directed team learning initiatives. Furthermore, the quality of self-directed team learning relied upon the effectiveness of air traffic control team performances.     

Correlation of motor skill,mental rotation,and working memory in 3- to 6-year-old children

A relationship between motor processes and mental rotation has been suggested by current research; however, the influence of working memory on this relationship has not yet been determined. Therefore, a correlation between motor tests, paper–pencil and chronometric mental rotation tests, and working memory tests were conducted in 3- to 6-year-old children. A stepwise multiple-regression showed that 55.5% of the variance was explained by the working memory tests: digit span forward and Corsi forward. This indicates that working memory and executive functions may play an important role in mental rotation and motor processes.     

Early and persistent motor difficulties in infants at-risk of developing autism spectrum disorder: A prospective study

Analyses were conducted in order to investigate motor development in younger siblings of children diagnosed with autism spectrum disorder (ASD). Infants at familial risk and low risk of developing ASD were tested longitudinally between the ages of 7 and 36 months. Data were analysed from motor scales on the Mullen Scales of Early Learning and the Vineland Adaptive Behaviour Scales at each age point. Significantly lower motor scores in at-risk infants were evident from the age of 7 months compared to the low-risk group. Infants who were later diagnosed with ASD demonstrated significantly poorer Fine Motor skills at 36 months than at-risk infants without any developmental difficulties. In addition, Gross Motor scores were highly correlated across the two measures for low-risk infants and infants who later developed ASD. Early motor difficulties may be an early indicator of a number of neurodevelopmental disorders, including ASD.     

The temporal dynamics of effect anticipation in course of action planning

“Strong” versions of the ideomotor theory of action control claim that anticipations of the environmental effects that actions bring about are mandatory for response selection. This is considered to be the one and only way of how actions can be voluntarily selected. We studied this notion in a series of four experiments where we adapted the flanker paradigm to investigate the involvement of effect codes in the preparation of motor responses. Participants first learned that their responses to stimulus letters were contingently followed by the presentation of a new letter on the screen. In the second phase of the experiments, the action-demanding letters were presented together with the effects of the correct response, effects of other responses, or neutral letters. Varying the stimulus onset asynchrony (SOA) between target stimuli and the flanking effect stimuli provides the opportunity to investigate the temporal dynamics of the activation of effect codes. Hence, flanker stimuli were presented before, simultaneously with, or after the onset of the target. The results indicate that effect-related information from the flanker stimuli is involved in the preparation process, but mainly in later phases of response preparation. The observed pattern of results suggests that, at least under conditions where responses are determined by stimuli, effect codes are activated in course of response planning to enable the evaluation of the executed response and the monitoring of response execution, but they do not automatically activate the responses themselves.     

Delayed auditory feedback in repetitive tapping: A role for the sensory goal

The open-loop model by Wing and Kristofferson has successfully explained many aspects of movement timing. A later adaptation of the model assumes that timing processes do not control the movements themselves, but the sensory consequences of the movements. The present study tested direct predictions from this “sensory-goals model”. In two experiments, participants were instructed to produce regular intervals by tapping alternately with the index fingers of the left and the right hand. Auditory feedback tones from the taps of one hand were delayed. As a consequence, regular intervals between taps resulted in irregular intervals between feedback tones. Participants compensated for this auditory irregularity by changing their movement timing. Compensation effects increased with the magnitude of feedback delay (Experiment 1) and were also observed in a unimanual variant of the task (Experiment 2). The pattern of effects in alternating tapping suggests that compensation processes were anticipatory—that is, compensate for upcoming feedback delay rather than being reactions to delay. All experiments confirmed formal model predictions. Taken together, the findings corroborate the sensory-goals adaptation of the Wing–Kristofferson model.     

驾驶员情绪状态研究

采用驾驶员情绪状态量表(DPOMS),对265名客车驾驶员的情绪状态进行了问卷调查。结果表明：(1)年龄对驾驶员的疲劳状态有显著影响,对其余各种情绪状态没有显著影响;(2)女驾驶员的紧张精绪显著高于男驾驶员,积极情绪(精力)显著于低于男驾驶员;(3)出租汽车驾驶员的愤怒、疲劳、紧张等消极精绪显著高于公交大客车驾驶员,积极情绪(精力)显著低于公交大客车驾驶员;(4)事故组驾驶员的愤怒、疲劳、紧张、慌乱等消极情绪显著高于安全组驾驶员,积极情绪(精力)显著低于安全组驾驶员。     

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.