Cognitive style in attainment of an upside-down posture in water with and without vision

It is well known that adopting a posture required by the central nervous system takes into account a frame of reference. This frame of reference is built on sensory information and, more particularly, on vision, which is often considered to be the main input. The contribution of vision varies by participant and defines their cognitive style. This study investigates the contribution of visual information and cognitive style to postural strategy and, more precisely, to the construction of an upside-down posture in an underwater condition. Eight synchronized swimmers performed the Rod-and-Frame Test (RFT) to assess their cognitive style and practiced upside-down posture in water to measure their body inclination. The Rod-and-Frame Test scores did not distinguish the participants, as the results of the test showed that most of them were visual-field independent. However, in a closed-eyes condition, participants achieved a more precise vertical position than when using translucent goggles.     

Can skilled performers readily change technique? An example, conventional to wave action breaststroke

There has been a paucity of research that has investigated whether skilled performers of a complex sports skill can readily change their technique. This study was designed to investigate whether swimmers skilled in the conventional breaststroke technique could adjust readily to the wave action technique. Nine masters swimmers with well established and stable movement patterns for the conventional technique were coached in the wave action breaststroke technique. The swimmers were videotaped from the side during maximum speed trials of the conventional breaststroke technique before coaching and the wave action technique after ten 45-minute coaching sessions. The amplitude and phase of the waveforms comprising the vertical displacements of the body parts were determined by Fourier analysis. In response to the coaching, the amplitude of the fundamental frequency of the vertex of the head, shoulders, hips, and knees increased significantly (p < 0.01). The percentage of power contained in the fundamental frequency of the shoulder and hip vertical displacements also increased significantly (p < 0.01). All subjects changed the relative phase of the fundamental frequencies of the vertex, shoulder, and hip vertical displacements. It was concluded that in this complex skill, major changes to the low frequency waveforms comprising the motion were achieved readily.     

Body-esteem, body mass index, and risk for disordered eating among adolescents in synchronized swimming

The aim of this study was to examine dimensions of body-esteem, Body Mass Index, and their relations with eating disorder symptoms among 42 elite adolescent athletes engaged in competitive synchronized swimming (M = 15.4 yr., SD = 1.2) and to compare them with 40 athletes in sports with no emphasis on leanness (M = 16.5 yr., SD = .93), and 50 nonathlete college female students (M = 16.3 yr., SD = 1.1). They completed the Body-esteem Scale and the Eating Attitudes Test, and the Body Mass Index was computed. Analysis showed synchronized swimmers reported greater negative feelings about their appearance than the two other groups and low perceptions of how others evaluate their physical appearance. Participants did not differ on the EAT-26. Regression analyses showed that Body Mass Index and Body-esteem Appearance accounted for 38% of the variance in log-transformed Dieting scores of synchronized swimmers. Results are discussed in relation to the literature.     

When the whole is more than the sum of its parts: Group motivation gains in the wild

Whereas negative effects of groups on individual motivation have been reported for many years, recent research has begun to show when and why working in a group can produce motivation gains compared to individual work. So far, this evidence has been limited to laboratory settings and rather simple tasks. Using data from swimming competitions at the 2008 Olympics, evidence is presented that motivation gains in groups also occur in field settings with more complex tasks. Based on an instrumentality × value approach, we expect that late positions in a relay trigger motivation gains in groups due to an increase in perceived indispensability for the group outcome. This idea has been initially tested in a pilot study with competitive swimmers, demonstrating that perceived indispensability for the relay outcome indeed increases with later serial positions in a relay. Moreover, the main study with data from the 2008 Olympics revealed performance times consistent with this pattern of indispensability perceptions: while starting swimmers in the swimming relays performed at similar levels as in their individual competitions, swimmers at the later positions showed higher performance in the relay compared to their individual competition heats.     

The role of vision in the temporal and spatial control of handwriting.

The general observation that handwriting is not noticeably impaired by the withdrawal of vision can be explained in two ways. One might argue that vision is not needed during the act of writing. Micro-analyses should then reveal that spatial as well as temporal writing features are identical in conditions of vision and no vision. Alternatively, it is possible that vision is needed during the act of writing, but that without vision possible errors and inaccuracies have to be prevented. Assuming that the latter would place an extra demand on movement control, this should be revealed by an increase in processing time. We have found evidence for the latter view in the present study in which 12 subjects wrote a nonsense letter sequence with and without vision. Close examination showed that writing shapes remained equally invariant under both vision conditions, suggesting that spatial control was unaffected by withdrawing vision. The prediction that invariance of shapes is preserved in the absence of vision at the expense of processing time increments was confirmed. The increase of reaction time observed when visual guidance was withdrawn suggests that more processing time was needed prior to the movement start. Moreover, the RT increment was larger when a short writing duration was instructed. The present findings will be discussed in light of the remarkable flexibility of writing as a motor skill in which writers appear to be able to employ specific strategies to preserve shape in the absence of visual guidance.     

The timing effects of accent production in synchronization and continuation tasks performed by musicians and nonmusicians

Two groups of subjects differing in their musical expertise produced periodic finger-tapping sequences involving a pattern of accentuation. In some situations, the taps were synchronized with the clicks of a metronome. We recorded the trajectory of the subjects' finger displacement in the vertical plane, and the force and the moment of occurrence of the taps on the response key. Musicians tended to equalize the durations of the downstrokes at all positions in the sequence. Nonmusicians moved their finger quickly to produce the accent, and more slowly to produce the subsequent tap. These variations in the movement-execution time were partly compensated by opposite variations in the onsets of the movements, e.g., the short-duration movements were delayed. Despite these differences in their movement strategies, musicians and nonmusicians generated very similar tap-timing profiles. The intertap interval after the accent was lengthened regardless of the subjects' musical expertise and the metronome conditions (metronome present or absent). The lengthening did not depend on whether the interval before the accent was shortened (without the metronome) or not (with the metronome). It is suggested that an internal timekeeper may generate temporal goal points at which the keytaps should occur. The lengthening of the interval after the accent is attributed to transient changes in the working of the internal clock.     

Arm coordination symmetry and breathing effect in front crawl

This study analysed the relationships among arm coordination symmetry, motor laterality and breathing laterality during a 100-m front crawl, as a function of expertise. Ten elite swimmers (G1), 10 mid-level swimmers (G2), and 8 non-expert swimmers (G3) composed three skill groups, which were distinguished by velocity, stroke rate, stroke length, breathing frequency (BF) and the mean number of strokes between two breaths - the stroke breath (SB) - over a 100-m front crawl. Four stroke phases were identified by video analysis (catch, pull, push and recovery) and the index of coordination (IdC) measured the lag time between the propulsive phases of the two arms. The three modes of coordination are catch-up (IdC<0%), opposition (IdC=0%) and superposition (IdC>0%). The IdC was established as the mean of IdC1 and IdC2, which measured the lag time between the propulsive phases of the left and right arms, respectively. The coordination symmetry was analysed by comparing IdC1 and IdC2, and the breathing effect was studied by distinguishing IdC1 (and IdC2) with and without breathing. Motor laterality was determined by an adaptation of the Edinburgh Handedness Inventory. Breathing laterality was determined by a questionnaire and observation during the 100-m trial. Most of the front crawl swimmers showed asymmetric arm coordination, with propulsive discontinuity on one side and propulsive superposition on the other. This asymmetry was most often related to breathing laterality (a preferential breathing side for a unilateral breathing pattern) and motor laterality (arm dominance), with different profiles noted. More than the breathing laterality itself, the breathing actions of the non-expert swimmers amplified their asymmetric coordination on the breathing side. Conversely, the elite swimmers, who had higher and more stable spatial-temporal parameters (velocity and stroke lengths), a high coordination value (IdC) and lower breathing frequency (BF), managed their race better than the less proficient swimmers and their asymmetric arm coordination was not disturbed by breathing actions. By determining the dominant arm and the preferential breathing side, the coach can obtain a swimmer profile that allows both coach and swimmer to better understand and respond to excessive coordination asymmetry.     

On-Line Updating of Spatial Information Druing Locomotion Without Vision

Two experiments are reported in which the control of locomotion without vision was investigated. In Experiment 1, subjects (N = 10) made similar, although less functional, locomotor adjustments when walking without vision to a target than they did when walking with vision. That result suggests that while walking without vision, the subjects updated their positions on-line with respect to a representation of the target rather than operating from a preformulated action plan. In Experiment 2, there was a significant weakening and loss of functionality of the locomotor adjustments when subjects (N = 10) had to walk without vision the correct distance to the target but in a direction opposite to its true location, as compared with when they walked without vision directly to the target. That finding suggests that the subjects were nonvisually updating their positions not with respect to an abstract representation of the target's distance but with respect to a representation of its relative location within the task environment.     

阅读障碍儿童与其年龄和能力匹配儿童阅读空格文本的注视位置效应

采用EyeLink II眼动仪, 选取阅读障碍儿童及与其年龄相同、阅读能力水平相同的儿童为被试, 要求他们阅读正常无空格和词间空格句子。结果发现, 在阅读正常无空格和词间空格句子时, 阅读障碍儿童与年龄匹配组和能力匹配组儿童一样, 单次注视时往往将首次注视定位于词的中心, 多次注视时首次注视往往落在词的开头; 当首次注视落在词的开头时再注视该词的概率增加, 而且再注视往往落在词的结尾部分。我们认为, 中国儿童在阅读过程中采用的是“战略-战术”策略。     

The relationship between psychological skills usage and competitive anxiety responses

Objectives. To investigate equivocal findings within the literature addressing the relationship between competitive anxiety responses and psychological skills. Intensity (i.e. level) and direction (i.e. interpretation of intensity as facilitative or debilitative) dimensions of competitive state anxiety and self-confidence were examined in performers with different levels of psychological skills usage.Design. Cross-sectional design assessing psychological constructs during competition. The independent variable was psychological skill usage (“high” and “low” groups) and dependent variables were competitive anxiety responses.Method. Non-elite competitive swimmers (N=114) completed a modified version of the Competitive State Anxiety Inventory-2 (CSAI-2) which examined both intensity and direction dimensions prior to racing. Following the event these participants completed the Test of Performance Strategies (TOPS) which measures psychological skills usage. Based on the TOPS scores the swimmers were dichotomised using post-hoc median-split into high and low usage groups for certain psychological skills.Results. MANOVAs revealed significant differences in the CSAI-2 scores between the high and low usage groups for the skills of relaxation, self-talk and imagery. ANOVAs indicated significant differences on all CSAI-2 subscales for relaxation groups, and differences on cognitive intensity, somatic direction and self-confidence for self-talk groups, and self-confidence for the imagery groups.Conclusions. Non-elite swimmers, in contrast with previous research examining elite swimmers (Hanton, S. & Jones, G. (1999a). The acquisition and development of cognitive skills and strategies: I. Making the butterflies fly in formation. The Sport Psychologist, 13, 1–21), primarily use relaxation strategies to reduce and interpret their anxiety intensity levels as facilitative, relying minimally on other psychological skills.     

Lower muscle co-contraction in flutter kicking for competitive swimmers

The purpose of this study was to examine the difference in muscle activation pattern and co-contraction of the rectus and biceps femoris in flutter-kick swimming between competitive and recreational swimmers, to better understand the mechanism of repetitive kicking movements during swimming. Ten competitive and 10 recreational swimmers swam using flutter kicks at three different velocities (100%, 90%, and 80% of their maximal velocity) in a swimming flume. Surface electromyographic signals (EMG) were obtained from the rectus (RF) and biceps femoris (BF), and lower limb kinematic data were obtained at the same time. The beginning and ending of one kick cycle was defined as when the right lateral malleolus reached its highest position in the vertical axis. The offset timing of muscle activation of RF in the recreational swimmers was significantly later at all velocities than in the competitive swimmers (47–48% and 26–33% of kick time of one cycle for recreational and competitive swimmers, respectively), although the kinematic data and other activation timing of RF and BF did not differ between groups. A higher integrated EMG of RF during hip extension and knee extension induced a higher level of muscle co-contraction between RF and BF in the recreational swimmers. These results suggest that long-term competitive swimming training can induce an effective muscle activation pattern in the upper legs.     

Evaluation of a coaching strategy to reduce swimming stroke errors with beginning age-group swimmers

A coaching strategy to decrease errors in swimming strokes with swimmers who had not improved under "standard" coaching procedures was investigated using a multiple baseline design across subjects and swimming strokes. The procedure resulted in a large decrease in errors on swimming strokes during sessions in a training pool. Stimulus generalization of improved performance to normal practice conditions in the regular pool was observed with all but one swimmer. This improvement was maintained during two maintenance phases lasting approximately 2 weeks, as well as under standard coaching conditions during at least a 2-week follow-up. For two swimmers, error rates on one of the strokes showed a gradual increase between the third and fifth week of follow-up, but brief remedial prompting sessions immediately corrected their performance. Some beneficial response generalization to other components of the stroke being trained was observed, but no improvements were found on untrained strokes. The error correction package did not disrupt practice, require excessive amounts of the coach's time, or necessitate the use of cumbersome apparatus. In addition, the coach and the swimmers considered the procedures to be effective, and expressed their willingness to participate in them again in the future.     

The role of body-esteem in predicting disordered eating symptoms: A comparison of French aesthetic athletes and non-athletic females

ObjectivesTo explore the relative contributions of self-esteem, body-esteem components and body mass index to disordered eating in aesthetic female athletes and non-athletic females and specifically to determine if the body-esteem components are risk factors for disordered eating.MethodsOne hundred and fifty two participants, of which 61 rhythmic gymnasts, 42 synchronized swimmers and a non-athletic group of 49 female college students completed the self-esteem scale, the body-esteem scale (satisfaction with general appearance, weight satisfaction and others' evaluations of one's body and appearance), the eating attitudes test, and the body mass index was computed.ResultsResults showed a strong heteroscedasticity for EAT-26 and therefore scores were modeled separately for the three groups. For rhythmic gymnasts, the final regression model only emphasizes the role of body-esteem attribution. For the synchronized swimmers, the final regression model combines two body-esteem dimensions (body-esteem for weight and body-esteem attribution) and their interaction. For the non-athletic group, the final regression model only emphasizes body-esteem for weight. Body mass index and low self-esteem were not predictive of disordered eating and no significant relationship was found between body-esteem for appearance and eating attitudes scores. The use of exploratory graphs such as graphs of conditioning and level plots provided more detailed information on the relationship between body-esteem dimensions and eating attitude scores.ConclusionsResults contributed to the growing literature on disordered eating suggesting that attention must be paid to body-esteem for weight and attribution in the understanding of disordered eating and their interaction. Future research should take into consideration the complexity of these results and use a larger sample of aesthetic athletes to elaborate on the current findings.     

Contextual interference effect on acquisition and retention of pistol-shooting skills

The effects of contextual interference on learning pistol-shooting skills in a natural training environment were examined. The shooting skills consisted of three "stages" with different requirements for the skill variations commonly used in the field. 12 participants were randomly assigned into one of two practice conditions, blocked vs serial. Following a 20-min. safety and skill instructional session, Blocked group practiced 10 trials in a row at each stage, while Serial group performed 5 trials in a row for each of the three stages and then repeated the cycle. Both groups completed a total of 30 practice trials over the three stages. A 10-min. rest interval was provided prior to a retention test which included 9 trials (3 trials at each stage in a blocked format). Results based on the data of Stage III, the most complex skill among the three stages, showed a pattern consistent with previous findings that practicing in the serial schedule depressed performance during initial training but maintained the performance better at retention, relative to the blocked practice.     

A Sensorimotor Basis for Motor Learning: Evidence Indicating Specificity of Practice

Our previous work (Proteau, Marteniuk, Girouard, & Dugas, 1987) was concerned with determining whether with relatively extensive practice on a movement aiming task, as the skill theoretically starts becoming open-loop, there would be evidence for a decreasing emphasis on visual feedback for motor control. We eliminated vision of the moving limb after moderate and extensive practice and found that the movement became more dependent on this feedback with greater amounts of practice. In the present study, we wished to test the hypothesis, developed from our previous work, that at the base of movement learning is a sensorimotor representation that consists of integrated information from central processes and sensory feedback derived from previous experiences on the movement task. A strong test of this hypothesis would be the prediction that for an aiming task, the addition of vision, after moderate and relatively extensive practice without vision, would lead to an increasingly large movement decrement, relative to appropriate controls. We found good support for this prediction. From these and previous results, and the idea of the sensorimotor representation underlying learning, we develop the idea that learning is specific to the conditions that prevail during skill acquisition. This has implications for the ideas of generalized motor program and schema theory.     

The independence of horizontal and vertical dimensions in handwriting with and without vision

The purpose of this study was to investigate the relationship between horizontal and vertical components of handwriting production when subjects were instructed to vary the size of these components separately or together. The effect of vision on these instructed size transformations also was examined. Eight female adults participated in the experiment. The basic task was to write the words 'poppy' and 'wood' cursively five times, the first time in their normal size and then with four size transformations. These transformations--one-fourth, one-half, double, and four-times their normal size--were made under three different sets of instructions (width only, height only, both) and in two visual conditions (normal, blindfolded), for a total of six sets of five repetitions. The individual slopes (changes in actual values across the transformation values) for width and height under instructions to change both parameters were almost identical to the width and height slopes under instructions to change only the single parameter, supporting the notion of the independence of the horizontal and vertical components. Further, an analysis of these individual slopes indicated that the size transformations were significantly greater (p less than 0.05) (and closer to the instructed values) with vision than without vision.     

Time perception is enhanced by task duration knowledge: Evidence from experienced swimmers

The present study deals with the impact on temporal estimation of previous knowledge about the duration of a specific task (referred to as ??task duration knowledge??). Athletes were recruited in this study because they are assumed to have high levels of task duration knowledge in their discipline. In Experiment 1, 28 elite swimmers had to estimate the time it would take to swim a given distance using two different strokes for which they had different task duration knowledge levels. The swimmers estimated duration more accurately and with less uncertainty in the high-knowledge than in the low-knowledge condition. In Experiment 2, the swimmers had to produce 36?s of swimming in various contexts that altered the retrieval of their task duration knowledge, with and without a secondary task. When swimmers could not rely on their task duration knowledge, their productions were more affected by the secondary task. In Experiment 3, the swimmers were more precise at producing time when visualising something that they knew well (swimming) rather than something that they had never experienced, which shows that physical execution is not a mandatory requirement for observing the enhancement effect resulting from task duration knowledge. These three converging experiments suggest that task duration knowledge is strongly involved in time perception.     

Meta-analysis of age and skill effects on recalling chess positions and selecting the best move

A meta-analysis was conducted of studies that measured the effects of both age and skill in chess on the tasks of selecting the best move for chess positions (the best move task) as well as recalling chess game positions (the recall task). Despite a small sample of studies, we demonstrated that there are age and skill effects on both tasks: age being negatively associated with performance on both tasks and skill being positively associated with performance on both tasks. On the best move task, we found that skill was the dominant effect, while on the recall task, skill and age were approximately equally strong effects. We also found that skill was best measured by the best move task. In the case of the best move task, this result is consistent with the argument that it accurately replicates expert performance (Ericsson & Smith, 1991). Results for the recall task argue that this task captures effects related to skill, but also effects likely due to a general aging process. Implications for our understanding of aging in skilled domains are also discussed.     

The Influence of Skill and Intermittent Vision on Dynamic Balance

Two experiments are reported in which expert and novice gymnasts were required to walk across a balance beam as quickly as possible in various vision conditions. In Experiment 1, experts walked faster than novices in all vision conditions, showing the greatest superiority when vision was completely eliminated. Novices were more dependent on vision and were able to maintain their performance as long as a visual sample was available every 250 ms (i.e: 4-Hz samples).The results of Experiment 2 indicate that differences between expert and novice performers in the no-vision condition were not related to the use of a short-term visual representation of the movement environment. Our movement time findings are problematic for specificity of learning models of skill acquisition. As well, film data collected in Experiment 2 were not consistent with models that propose a transition from closed-loop to open-loop control.     

Visual, kinaesthetic and cross-modal development: relationships to motor skill development

The ability of children between the ages of 5 and 10 years to match the length of lines within and between the modalities of vision and kinaesthesis was studied. No evidence was found for specific increases in cross-modal skill which could not be explained in terms of within-modal development. Performance in the perceptual task was related to measures of developing motor skill in the children. Substantial relationships were found between performance on the within-modal tasks and motor skill, but no significant relationships were found between cross-modal measures and motor skill development. It is concluded that the development of cross-modal integration is not a major determinant of motor skill development.