Training referential communicative skills to individuals with autism spectrum disorder: a pilot study

The present study reports the effects of referential communication training in individuals formally diagnosed with autism spectrum disorder (ASD). Participants were 20 children with ASD (M age = 14.3 yr., SD = 4.2; 6 girls, 14 boys) in the role of speakers and 20 control children, who acted as listeners. They were all enrolled in mainstream compulsory education. Inclusion/exclusion criteria were defined according to the clinical diagnosis of ASD, the presence or absence of additional or associated disability, previous training in referential communication, and any drug treatment. Speakers were randomly assigned to one of two groups (trained vs untrained). Linguistic age, cognitive level and autistic symptoms were analyzed, respectively, with the Peabody Picture Vocabulary Test (PPVT), the Wechsler Intelligence Scale (WISC-R or WAIS-III), and the Autistic Behavior Checklist (ABC). Communicative abilities were analyzed through two indexes related to message complexity and self-regulation. The trained group was trained in referential communication tasks (task analysis, role taking, and task evaluation), while the untrained group took part in a communicative game but without any specific communicative training. The results showed that the complexity of emitted messages had improved statistically significantly in the trained group as an effect of training. Ecological referential communication is shown to be an appropriate paradigm for studying the communicative process and its products and could be used to develop and implement a training program focused on those skills in which individuals with ASD are most deficient.     

A comparison between novices and experts of the velocity-accuracy trade-off in overarm throwing

Expert team-handball players do not show the typical trade-off between speed and accuracy in overarm throwing. Van den Tillaar and Ettema (2003a) attributed this result to the uniqueness of the training experience of this group. The purpose of this study was to test their hypothesis by comparing experts with novices on overarm throwing by manipulating the goal of the task using different instructions. No trade-off between speed and accuracy was found for novices (n = 13; M age = 22.7 yr., SD = 2.2) or experts (n = 9; Mage = 24 yr., SD = 2.2): accuracy did not change by instruction. Furthermore, the linear velocities of the ball and endpoints of body segments and their timing were affected by instruction in a similar fashion in both groups. This finding indicates that training experience is not related to speed-accuracy tradeoff in overarm throwing.     

Relative and absolute stability in perceived parenting behaviour: a longitudinal study with children and adolescents

Patterns of relative and absolute stability in parental behaviour with children and adolescents are reported. The sample comprised 523 youth (58.7% girls). Data were collected at three time periods: T1 (M age = 11.1 yr.), T2 (M age = 12.2 yr.), and T3 (M age = 13.2 yr.), each separated by one year. According to children's reports, relative consistency was moderate in both mothers and fathers, particularly as regards communication and strict control. In contrast, as children got older, parental rearing practices related to strict control and hostility decreased. There was a similarity between fathers and mothers in terms of relative and absolute stability. Relative stability was affected by the child's sex, the parenting variable, and the time period; however, the patterns of absolute stability reveal no differences by sex.     

Changes in recovery-stress state and performance in elite rowers during preparation for major competitions

This study investigated changes in the perceived recovery-stress state and performance in 6 highly trained Estonian rowers preparing for major competitions and representing Estonia in double sculls (age: M = 23.0, SD = 1.4 yr.; height: M = 198.0, SD = 0.0 cm; body mass: M = 97.1, SD = 6.4 kg), and quadruple sculls (age: M = 21.5, SD = 2.5 yr.; height: M = 189.5, SD = 5.4 cm; body mass: M = 90.9, SD = 4.8 kg). The subjects were training regularly and had been doing so for the last 10.5 yr. (double scullers, SD = 2.1 yr.) and 7.5 yr. (quadruple scullers, SD = 3.1 yr.), respectively. The Recovery-Stress Questionnaire for Athletes of Kellmann and Kallus was given two days before World Cup competitions. Standardized Stress and Standardized Recovery scores and RESTQ-Index were computed. In addition, resting cortisol in blood was measured at the same time. The performance of both boat classes constantly decreased from World Cup 1 to World Cup 3 as indicated by percent losses for winning boats. Resting cortisol and RESTQ-Index increased and decreased, respectively, at the same time. For double scullers, a decrease in RESTQ-Index mainly reflected the large decrease in the Standardized Recovery score. A decrease in RESTQ-Index was mainly based on a large increase in the Standardized Stress score for rowers performing in a quadruple scull. Present results indicate that the recovery-stress state affects performance of rowers in international competitions. RESTQ-Index could be used as the athletes' resource measure, while the Standardized Stress and Standardized Recovery scores reflect the athletes' extent of stress and recovery separately.     

The self: Your own worst enemy? A test of the self-invoking trigger hypothesis

The self-invoking trigger hypothesis was proposed by Wulf and Lewthwaite [Wulf, G., & Lewthwaite, R. (2010). Effortless motor learning? An external focus of attention enhances movement effectiveness and efficiency. In B. Bruya (Ed.), Effortless attention: A new perspective in attention and action (pp. 75–101). Cambridge, MA: MIT Press] as a mechanism underlying the robust effect of attentional focus on motor learning and performance. One component of this hypothesis, relevant beyond the attentional focus effect, suggests that causing individuals to access their self-schema will negatively impact their learning and performance of a motor skill. The purpose of the present two studies was to provide an initial test of the performance and learning aspects of the self-invoking trigger hypothesis by asking participants in one group to think about themselves between trial blocks—presumably activating their self-schema—to compare their performance and learning to that of a control group. In Experiment 1, participants performed 2 blocks of 10 trials on a throwing task. In one condition, participants were asked between blocks to think about their past throwing experience. While a control group maintained their performance across blocks, the self group's performance was degraded on the second block. In Experiment 2, participants were asked to practice a wiffleball hitting task on two separate days. Participants returned on a third day to perform retention and transfer tests without the self-activating manipulation. Results indicated that the self group learned the hitting task less effectively than the control group. The findings reported here provide initial support for the self-invoking trigger hypothesis.     

Relationship of sports experience and ego development of adolescent Japanese athletes

This study examined the relationship of sports experience with ego development. A questionnaire was used to assess experience of Crisis, Exploration, and Commitment in the issues of Athletic Performance and of Being a Teammate in 782 adolescent Japanese athletes (423 boys, M age = 15.2 yr.; 359 girls, M age = 15.0 yr.). Their Ego Levels were assessed using the Washington University Sentence Completion Test. Correlations indicated that scores on Crisis, Exploration, and Commitment in the issues of Athletic Performance and Being a Teammate were generally associated with Ego Development. Multiple regression analyses indicated that, for boys, the issue of Athletic Performance was closely associated with Ego Development, while for girls, the issue of Being a Teammate was closely associated with Ego Development. Sports experience with crisis, exploration, and commitment may be related to accommodation, which is, in turn, related to ego development. The sex differences on issues related to ego development may be associated with differences in sex-role development for boys and girls.     

Validity and internal consistency reliability of a computerized test to assess prone extension in children ages four to six years

The objective of this study was to develop a computerized test of prone extension to measure performance of prone extension in children 4 to 6 years of age. The participants were selected from kindergartens, comprising 132 boys and 107 girls with a mean age of 5 yr. 2 mo. (SD = 6 mo.). Sensitivity and specificity of the computerized test of prone extension were assessed by comparison with the judgments of an expert, an occupational therapist with more than 20 yr. of pediatric experience, as the criterion standard. The computerized test of prone extension identified children with poor outcomes with a sensitivity of 0.83, a specificity of 0.88, and an accuracy of 0.87. The internal reliability index was 0.81. The computerized test of prone extension could be of value in detecting problems of antigravity posture in prone extension and permitting early intervention to correct it.     

Age, sex, and body mass index in performance of selected locomotor and fitness tasks by children in grades K-2

The purpose of this study was to examine the contributions of 3 predictor variables (age, sex, and body mass index) to performance of 7 fundamental movement skills (locomotor; run, gallop, hop, leap, jump, skip, and slide) and 4 fitness tasks (grip strength, step test, sit and reach, and timed sit-ups) by 65 children in Grades K-2 (M=6 yr.). A multiple regression analysis indicated that running, leaping, and skipping improved with age. No sex differences were observed on any of the seven skills. In terms of the four fitness tasks, age was positively associated with timed sit-ups and grip strength and inversely associated with step-test performance. Sex was associated with step-test and sit and reach performance (girls performed better on both). Finally, body mass index was related to increased grip strength and fewer timed sit-ups.     

Movement variability and skill level of various throwing techniques

In team-handball, skilled athletes are able to adapt to different game situations that may lead to differences in movement variability. Whether movement variability affects the performance of a team-handball throw and is affected by different skill levels or throwing techniques has not yet been demonstrated. Consequently, the aims of the study were to determine differences in performance and movement variability for several throwing techniques in different phases of the throwing movement, and of different skill levels. Twenty-four team-handball players of different skill levels (n=8) performed 30 throws using various throwing techniques. Upper body kinematics was measured via an 8 camera Vicon motion capture system and movement variability was calculated. Results indicated an increase in movement variability in the distal joint movements during the acceleration phase. In addition, there was a decrease in movement variability in highly skilled and skilled players in the standing throw with run-up, which indicated an increase in the ball release speed, which was highest when using this throwing technique. We assert that team-handball players had the ability to compensate an increase in movement variability in the acceleration phase to throw accurately, and skilled players were able to control the movement, although movement variability decreased in the standing throw with run-up.     

Stereo disparity facilitates view generalization during shape recognition for solid multipart objects

Current theories of object recognition in human vision make different predictions about whether the recognition of complex, multipart objects should be influenced by shape information about surface depth orientation and curvature derived from stereo disparity. We examined this issue in five experiments using a recognition memory paradigm in which observers (N = 134) memorized and then discriminated sets of 3D novel objects at trained and untrained viewpoints under either mono or stereo viewing conditions. In order to explore the conditions under which stereo-defined shape information contributes to object recognition we systematically varied the difficulty of view generalization by increasing the angular disparity between trained and untrained views. In one series of experiments, objects were presented from either previously trained views or untrained views rotated (15°, 30°, or 60°) along the same plane. In separate experiments we examined whether view generalization effects interacted with the vertical or horizontal plane of object rotation across 40° viewpoint changes. The results showed robust viewpoint-dependent performance costs: Observers were more efficient in recognizing learned objects from trained than from untrained views, and recognition was worse for extrapolated than for interpolated untrained views. We also found that performance was enhanced by stereo viewing but only at larger angular disparities between trained and untrained views. These findings show that object recognition is not based solely on 2D image information but that it can be facilitated by shape information derived from stereo disparity.     

Children's autokinetic movement as a function of inferred movement of target shape

Four target shapes, a control stimulus (circle) and one each representing geometrical (arrow), representational (car), and symbolic (cross) implied movement were presented to 10 children in each of five age groups of boys and girls (4, 6, 8, 10, 12 yr.) in an autokinetic movement task. While there were no differences in direction of perceived movement with regard to the control stimulus (circle), all other target shapes showed a decrease in the effects of implied movement with increases in age. The minor sex differences were not reported.     

Multi-body dynamic coupling mechanism for generating throwing arm velocity during baseball pitching

The purpose of this study was to identify the detailed mechanism how the maximum throwing arm endpoint velocity is determined by the muscular torques and non-muscular interactive torques from the perspective of the dynamic coupling among the trunk, thorax and throwing and non-throwing arm segments. The pitching movements of ten male collegiate baseball pitchers were measured by a three-dimensional motion capture system. Using the induced-segmental velocity analysis (IVA) developed in this study, the maximum fingertip velocity of the throwing arm (MFV) was decomposed into each contribution of the muscular torques, passive motion-dependent torques due to gyroscopic moment, Coriolis force and centrifugal force, and other interactive torque components. The results showed that MFV (31.6 ± 1.7 m/s) was mainly attributed to two different mechanisms. The first is the passive motion-dependent effect on increasing the angular velocities of three joints (thorax rotation, elbow extension and wrist flexion). The second is the muscular torque effect of the shoulder internal rotation (IR) torque on generating IR angular velocity. In particular, the centrifugal force-induced elbow extension motion, which was the greatest contributor among individual joint contributions, was caused primarily by the angular velocity-dependent forces associated with the humerus, thorax, and trunk rotations. Our study also found that a compensatory mechanism was achieved by the negative and positive contributions of the muscular torque components. The current IVA is helpful to understand how the rapid throwing arm movement is determined by the dynamic coupling mechanism.     

The effect of type of practice on motor learning in children

The present investigation was concerned with the variability-of-practice hypothesis of Schmidt's schema theory of motor learning; i. e. it was sought to determine if there is an optimal way to structure the variable practice session with regard to schema formation. Furthermore, children's motor recognition (movement evaluation) was examined, in addition to recall (movement production), since apparently no such studies had been done within the context of schema theory before. Eighty-eight girls and boys with a mean age of 11.3 years were tested on a throwing task. Three groups of subjects practised under variable conditions (different target distances and weights) that differed with regard to contextual interference and sequential organization of task variations; another group received constant throwing practice. Following practice trials with knowledge of results, the four treatment groups and a control group without prior practice were required to produce and evaluate a novel response (novel target distance and weight) without vision and knowledge of results. The results supported the variability-of-practice hypothesis, in that variable practice in general facilitated recall and recognition on the novel task. Furthermore, variable practice with the highest level of contextual interference (random order of tasks) produced most effective transfer performance, suggesting that the structure of the variable-practice session in fact plays a role with regard to the effectiveness of motor schema development. Contrary to the ‘organization hypothesis’ (Gentile and Nacson, 1976) a hierarchical organization of movement variations was not more beneficial to schema formation than random practice.     

Hereditary determinants of manual torque

Data from a longitudinal study of twin children and siblings, 155 girls and 134 boys (aged 4 to 9 yr.), on a torque test confirmed that during this age period manually produced circling patterns change from clockwise to counterclockwise orientation. A genetic influence is suggested.     

Perception of a throwing action from point-light demonstrations

80 adults (40 men and 40 women) aged 18 to 25 yr. and 80 boys aged 14 to 15 yr. observed a throwing action presented in point-light form at a frontoparallel viewpoint either as a video film or computer simulation of the actor. The display consisted of the relative motion of the wrist, elbow, and shoulder joints of the throwing arm. Subjects were asked to report what they observed. The action was recognised immediately by 68% of all subjects, and this value increased to 90% with one more viewing of the demonstration. Response was virtually the same for both types of display, and there were no differences between adults and children. The results were similar to those from other studies from which researchers have concluded that kinematic information alone is sufficient to permit perception of fundamental patterns of movement.     

Perceptual learning of a non-focal color discrimination between ages three and six

A match-to-sample task and a preference-ranking procedure were used to provide predifferentiation experiences on a color discrimination of 3-, 4-, 5-, and 6-year-old children. Chronological age was the best predictor of task success. Six-year-olds averaged twice as many correct matches as 3-year-olds. Gender and predifferentiation experience were not significant as main effects or in interactions affecting test performance. There was no difference between scores of untrained and trained children. The predifferentiation experiences had no effect. The data suggest that the years between 3 and 6 may be an important period in the development of the perceptual abilities needed to discriminate among subtle differences in one hue. Boys' and girls' abilities seem to develop at the same rate during this age span.     

The nature of control by spoken words over visual stimulus selection.

Eight retarded adolescents were trained to select one (a trained S+) of two visual stimuli in response to a spoken word (a trained word). Two different visual stimuli alternated randomly as the S-. To determine if the spoken work was merely a temporal discriminative stimulus for when to respond, or if it also specified which visual stimulus to select, the subjects were given intermittent presentations of untrained (novel) spoken words. All subjects consistently selected the trained S+ in response to the trained spoken word and selected the previous S- in response to the untrained spoken words. It was hypothesized that the subjects were responding away from the trained S+ in response to untrained spoken words, and control by untrained spoken words would not be observed when the trained S+ was not present. The two visual S- stimuli selected on trials of untrained spoken words were presented simultaneously. The untrained spoken words presented on these trials no longer controlled stimulus selections for seven subjects. The results supported the hypothesis that previous control by spoken words was due to responding away from the trained S+ in response to untrained spoken words.     

Performance gains from directed training do not transfer to untrained tasks

Given the increasing complexity of the tasks and skills needed in modern society, developing effective training strategies is of tremendous practical importance. Furthermore, training that improves performance of both trained and untrained tasks would be highly efficient. In the present study, we examined how directed training contributes to skill acquisition, and more importantly, to engendering transfer of training to untrained tasks. Participants learned a complex video game for 30 h (Space Fortress, Donchin, Fabiani, & Sanders, 1989) using one of two training regimens: Hybrid Variable-Priority Training (HVT), with a focus on improving specific skills and managing task priority, or Full Emphasis Training (FET) in which participants simply practiced the game to obtain the highest overall score. We compared game performance, retention of training gains, and transfer of training to untrained tasks as a function of the training regimen. Compared to FET, HVT learners reached higher levels of mastery on the game and HVT was particularly beneficial for initially poor performing participants. This benefit persisted seven months after training. However, contrary to expectation, both HVT and FET were unsuccessful in producing transfer to untrained tasks compared to a group that received limited game experience, suggesting that directed training and practice can produce task-specific improvements, but improvements do not necessarily transfer from trained to untrained tasks.     

Temporal and spatial parameters of stepping in place in children and adults

Characteristics of synchronized and self-paced stepping in place were examined by analyzing a temporal parameter (step frequency) and a spatial parameter (step height). Participants were 20 adults (10 women, 10 men; M age = 22.5 yr., range = 21-23) and 10 children (5 girls, 5 boys; M age=6.1 yr., range = 5-6). Results indicated that: (1) the step frequencies, which were equivalent for both groups, were well coincident with stimulus frequencies; (2) when step frequencies were imposed, the step height decreased with increasing step frequency, except for the lowest frequency condition in children; (3) movement consistency was the highest at 2 Hz and deteriorated if the step frequency was higher or lower; and (4) the self-paced stepping in place was optimal in terms of movement consistency. These results showed that stepping in place is a rhythmic movement at a given range of frequency which is coordinated so as to keep the product of step frequency and step height constant.     

A motion capture library for the study of identity, gender, and emotion perception from biological motion

We present the methods that were used in capturing a library of human movements for use in computer-animated displays of human movement. The library is an attempt to systematically tap into and represent the wide range of personal properties, such as identity, gender, and emotion, that are available in a person's movements. The movements from a total of 30 nonprofessional actors (15 of them female) were captured while they performed walking, knocking, lifting, and throwing actions, as well as their combination in angry, happy, neutral, and sad affective styles. From the raw motion capture data, a library of 4,080 movements was obtained, using techniques based on Character Studio (plug-ins for 3D Studio MAX, AutoDesk, Inc.), MATLAB The MathWorks, Inc.), or a combination of these two. For the knocking, lifting, and throwing actions, 10 repetitions of the simple action unit were obtained for each affect, and for the other actions, two longer movement recordings were obtained for each affect. We discuss the potential use of the library for computational and behavioral analyses of movement variability, of human character animation, and of how gender, emotion, and identity are encoded and decoded from human movement.