Ian M. Franks

Sport competition as a dynamical self-organizing system

The existence of structure in sport competition is implicated in the widespread practice of using the information gathered from a past contest to prepare for a future contest. Based on this reasoning, we previously analysed squash match-play for evidence of signature traits from among the stochastic relations between the various types of shot. The mixed findings from these analyses led us to re-analyse squash match-play as a dynamical system. Here, we extend this line of investigation with some suggestions as to how various sports might be described further within this theoretical framework. We offer some examples of dynamical interactions in dyadic (i.e. one vs one) and team (e.g. many vs many) sports, as well as some predictions from a dynamical systems analysis for these types of sports contests. This paper should serve to initiate further research into the complex interactions that occur in sport competition.

Analysis of passing sequences, shots and goals in soccer

Early research into how goals were scored in association football (Reep and Benjamin, 1968) may have shaped the tactics of British football. Most coaches have been affected, to a greater or lesser extent, by the tactics referred to as the “long-ball game” or “direct play”, which was a tactic employed as a consequence of this research. Data from these studies, published in the late 1960s, have been reconfirmed by analyses of different FIFA World Cup tournaments by several different research groups. In the present study, the number of passes that led to goals scored in two FIFA World Cup finals were analysed. The results conform to that of previous research, but when these data were normalized with respect to the frequency of the respective lengths of passing sequences, there were more goals scored from longer passing sequences than from shorter passing sequences. Teams produced significantly more shots per possession for these longer passing sequences, but the strike ratio of goals from shots is better for “direct play” than for “possession play”. Finally, an analysis of the shooting data for successful and unsuccessful teams for different lengths of passing sequences in the 1990 FIFA World Cup finals indicated that, for successful teams, longer passing sequences produced more goals per possession than shorter passing sequences. For unsuccessful teams, neither tactic had a clear advantage. It was further concluded that the original work of Reep and Benjamin (1968), although a key landmark in football analysis, led only to a partial understanding of the phenomenon that was investigated.

Advances in the application of information technology to sport performance

This paper overviews the diverse information technologies that are used to provide athletes with relevant feedback. Examples taken from various sports are used to illustrate selected applications of technology-based feedback. Several feedback systems are discussed, including vision, audition and proprioception. Each technology described here is based on the assumption that feedback would eventually enhance skill acquisition and sport performance and, as such, its usefulness to athletes and coaches in training is critically evaluated.

Modelling coaching practice: the role of instruction and demonstration

In this paper, we review the empirical literature pertaining to the effectiveness of instructions and movement demonstrations. Initially, we examine existing theories and approaches that try to explain the process of skill acquisition so as to determine implications of these theories for instructional provision. This is followed by an evaluation of studies in the motor learning literature in which pre-practice information has been manipulated. Explicit learning strategies are contrasted to implicit and discovery learning methods, and current explanations for instructional effects are discussed in terms of such mechanisms as effects-related attentional focus and movement variability. In the final sections, we review data from our own laboratory where pre-practice information has been manipulated during the learning of a novel bimanual coordination task. From these studies, proposals are made to try and explain how pre-practice information works to effect the process of skill acquisition, including the selection and execution of a response and the processing of associated feedback. An important role is given to the existing skills of the learner in understanding the instructions and performing the desired movement. Finally, we suggest some practical implications of this empirical evidence for the teaching of motor skills.

Prepared Movements Are Elicited Early by Startle

A startle stimulus has been shown to elicit a ballistic response in a reaction time (RT) task at very short latencies without involvement of the cerebral cortex (J. Valls-Solé, J. C. Rothwell, F. Gooulard, G. Cossu, & E. Muñoz, 1999). The present authors examined the nature of the startle response. A simple RT task was used in which 8 participants performed arm extension movements to 3 target distances (20deg;, 40deg;, and 60deg;) in a blocked design. An unpredictable startling acoustic stimulus (124 dB) replaced the imperative stimulus in certain trials. The authors verified the presence of a startle response independent from the prepared response by observing electromyographic (EMG) activity in sternocleidomastoid and orbicularis oculi muscles. Findings indicated that when the participant was startled, the intended voluntary response was produced at significantly shorter response latencies. Furthermore, the kinematic variables of the observed response during startle trials for all 3 target distances were mostly unchanged. The EMG characteristics of the responses were not modified, indicating that the response produced was indeed the prepared and intended response.

Inferring online and offline processing of visual feedback in target-directed movements from kinematic data

Vision plays an important role in the planning and execution of target-directed aiming movements. In this review, we highlight the limitations that exist in detecting visual regulation of limb trajectories from traditional kinematic analyses such as the identification of discontinuities in velocity and acceleration. Alternative kinematic analyses that involve examining variability in limb trajectories to infer visual control processes are evaluated. The basic assumption underlying these methods is that noise exists in the neuromotor system that subsequently leads to variability in motor output. This leads to systematic relations in limb trajectory variability at different stages of the movement that are altered when trajectories are modified during movement execution. Hence, by examining the variability in limb trajectories and correlations of kinematic variables throughout movement for vision and no vision conditions, the contribution of visual feedback in the planning and control of movement can be determined.

The Effect of Practice on the Control of Rapid Aiming Movements: Evidence for an Interdependency Between Programming and Feedback Processing

The purpose of this experiment was to investigate how the control of aiming movements performed as fast and as accurately as possible changes with practice. We examined: (1) the influence of visual feedback on the initial impulse and error correction phases of aiming movements during acquisition; and (2) the effect of removing visual feedback at different levels of practice. Results from the acquisition trials indicated that vision had a major impact on the organization of the initial impulse and error correction phases. Also, consistent with findings from research involving temporally constrained movements, the cost of removing vision was greater after extensive levels than after moderate levels of practice. Collectively, these results denote the importance of visual feedback to the learning of this particular class of aiming movements. Learning appears to be a dual process of improved programming of the initial impulse and increased efficiency of feedback processing. Practice not only acts on programming and feedback processes directly, but also indirectly through a reciprocal interplay between these two processes.

Considerations for the use of a startling acoustic stimulus in studies of motor preparation in humans

Recent studies have used a loud (> 120 dB) startle-eliciting acoustic stimulus as a probe to investigate early motor response preparation in humans. The use of a startle in these studies has provided insight into not only the neurophysiological substrates underlying motor preparation, but also into the behavioural response strategies associated with particular stimulus-response sets. However, as the use of startle as a probe for preparation is a relatively new technique, a standard protocol within the context of movement paradigms does not yet exist. Here we review the recent literature using startle as a probe during the preparation phase of movement tasks, with an emphasis on how the experimental parameters affect the results obtained. Additionally, an overview of the literature surrounding the startle stimulus parameters is provided, and factors affecting the startle response are considered. In particular, we provide a review of the factors that should be taken into consideration when using a startling stimulus in human research.

The Role of Video in Facilitating Perception and Action of a Novel Coordination Movement

Abstract Two groups (n = 10 in each) practiced a novel, bimanual coordination pattern that was demonstrated on video. One of the groups received augmented video feedback of their own responses after each trial following a demonstration. The video-feedback group showed better performance in acquisition and retention than the no-feedback group. On error-detection tests, the video-feedback group was better able to distinguish between correct and incorrect movement patterns. The authors concluded that video feedback helps to make relative phase information salient by aiding the discrimination process. Prepractice ability on a scanning task revealed that individuals who persevered with inphase-type movements, even though the task demands dictated otherwise, had the most difficulty determining and subsequently performing the required movement. Video feedback helped them to compensate for those difficulties.

The effects of changing movement velocity and complexity on response preparation : evidence from latency, kinematic, and EMG measures

SummaryIf movement control is afforded through the advance planning, or preprogramming, of upcoming actions, then one of the behavioral outcomes should be an increase in reaction time (RT) as the movement becomes more complex. In some situations, however, RT does not increase across levels of complexity, rather it remains invariant. In these cases, on-line preparation is typically inferred. That is, the sequence is said to be prepared in parts throughout the movement, as opposed to entirely beforehand. Given that there is some planning occurring during the sequence, then evidence of this process should be apparent within the movement itself. Three such dependent variables appear to provide such evidence. Specifically, the number of times the underlying accelerations cross the zero line within the movement, the number of ‘significant deviations’ within the acceleration trace, and the length of time for which the muscles are active (as measured by EMG) in relation to the duration of the movement. In the present experiment, then, these variables were measured in addition to the time required to prepare and initiate a movement performed under conditions conducive to either preprogramming or online preparation. Specifically, the movements were either completed as fast as possible, or at a considerably slower, more controlled speed. Each of the dependent variables displayed evidence of preprogramming in the movements completed at the fast velocity, and on-line preparation in the slower paced movements. Thus, in the slow condition, subjects appeared to rely more heavily on on-line prepared adjustments to produce an accurate outcome. The convergence attained between the various dependent measures lends power to the conclusions regarding hypothesized modes of control within the different speeds of movement.