Effects of different practice task constraints on fluctuations of player heart rate in small-sided football games

This paper analyzes effects of different practice task constraints on heart rate (HR) variability during 4v4 smallsided football games. Participants were sixteen football players divided into two age groups (U13, Mean age: 12.4±0.5 yrs; U15: 14.6±0.5). The task consisted of a 4v4 sub-phase without goalkeepers, on a 25x15 m field, of 15 minutes duration with an active recovery period of 6 minutes between each condition. We recorded players’ heart rates using heart rate monitors (Polar Team System, Polar Electro, Kempele, Finland) as scoring mode was manipulated (line goal: scoring by dribbling past an extended line; double goal: scoring in either of two lateral goals; and central goal: scoring only in one goal). Subsequently, %HR reserve was calculated with the Karvonen formula. We performed a time-series analysis of HR for each individual in each condition. Mean data for intra-participant variability showed that autocorrelation function was associated with more short-range dependence processes in the “line goal” condition, compared to other conditions, demonstrating that the “line goal” constraint induced more randomness in HR response. Relative to inter-individual variability, line goal constraints demonstrated lower %CV and %RMSD (U13: 9% and 19%; U15: 10% and 19%) compared with double goal (U13: 12% and 21%; U15: 12% and 21%) and central goal (U13: 14% and 24%; U15: 13% and 24%) task constraints, respectively. Results suggested that line goal constraints imposed more randomness on cardiovascular stimulation of each individual and lower inter-individual variability than double goal and central goal constraints.

GameFlow : a model for evaluating player enjoyment in games

Although player enjoyment is central to computer games, there is currently no accepted model of player enjoyment in games. There are many heuristics in the literature, based on elements such as the game interface, mechanics, gameplay, and narrative. However, there is a need to integrate these heuristics into a validated model that can be used to design, evaluate, and understand enjoyment in games. We have drawn together the various heuristics into a concise model of enjoyment in games that is structured by flow. Flow, a widely accepted model of enjoyment, includes eight elements that, we found, encompass the various heuristics from the literature. Our new model, GameFlow, consists of eight elements -- concentration, challenge, skills, control, clear goals, feedback, immersion, and social interaction. Each element includes a set of criteria for achieving enjoyment in games. An initial investigation and validation of the GameFlow model was carried out by conducting expert reviews of two real-time strategy games, one high-rating and one low-rating, using the GameFlow criteria. The result was a deeper understanding of enjoyment in real-time strategy games and the identification of the strengths and weaknesses of the GameFlow model as an evaluation tool. The GameFlow criteria were able to successfully distinguish between the high-rated and low-rated games and identify why one succeeded and the other failed. We concluded that the GameFlow model can be used in its current form to review games; further work will provide tools for designing and evaluating enjoyment in games.

Working in Australia's digital games industry consolidation report

The Working in Australia’s Digital Games Industry: A Consolidation Report is the outcome of a comprehensive study on the games industry in Australia by Dr Sandra Haukka from the ARC Centre of Excellence for Creative Industries and Innovation (CCI) based at Queensland University of Technology in Brisbane. The study responds to concerns that Australia’s games industry would not reach its full potential due to a lack of local, highly skilled staff, and a lack of appropriately trained graduates with the necessary knowledge and skills. This is the first of two reports produced with the support of the Games Developers’ Association of Australia. Over coming months researchers will develop a future skills strategy report for the industry.

Optimal strategies and minimax lower bounds for online convex games

A number of learning problems can be cast as an Online Convex Game: on each round, a learner makes a prediction x from a convex set, the environment plays a loss function f, and the learner’s long-term goal is to minimize regret. Algorithms have been proposed by Zinkevich, when f is assumed to be convex, and Hazan et al., when f is assumed to be strongly convex, that have provably low regret. We consider these two settings and analyze such games from a minimax perspective, proving minimax strategies and lower bounds in each case. These results prove that the existing algorithms are essentially optimal.

Current AI in games : a review

As the graphics race subsides and gamers grow weary of predictable and deterministic game characters, game developers must put aside their “old faithful” finite state machines and look to more advanced techniques that give the users the gaming experience they crave. The next industry breakthrough will be with characters that behave realistically and that can learn and adapt, rather than more polygons, higher resolution textures and more frames-per-second. This paper explores the various artificial intelligence techniques that are currently being used by game developers, as well as techniques that are new to the industry. The techniques covered in this paper are finite state machines, scripting, agents, flocking, fuzzy logic and fuzzy state machines decision trees, neural networks, genetic algorithms and extensible AI. This paper introduces each of these technique, explains how they can be applied to games and how commercial games are currently making use of them. Finally, the effectiveness of these techniques and their future role in the industry are evaluated.

Reliability of near-infrared spectroscopy for measuring biceps brachii oxygenation during sustained and repeated isometric contractions

We examine the test-retest reliability of biceps brachii tissue oxygenation index (TOI) parameters measured by near-infrared spectroscopy during a 10-s sustained and a 30-repeated (1-s contraction, 1-s relaxation) isometric contraction task at 30% of maximal voluntary contraction (30% MVC) and maximal (100% MVC) intensities. Eight healthy men (23 to 33 yr) were tested on three sessions separated by 3 h and 24 h, and the within-subject reliability of torque and each TOI parameter were determined by Bland-Altman+/-2 SD limits of agreement plots and coefficient of variation (CV). No significant (P>0.05) differences between the three sessions were found for mean values of torque and TOI parameters during the sustained and repeated tasks at both contraction intensities. All TOI parameters were within+/-2 SD limits of agreement. The CVs for torque integral were similar between the sustained and repeated task at both intensities (4 to 7%); however, the CVs for TOI parameters during the sustained and repeated task were lower for 100% MVC (7 to 11%) than for 30% MVC (22 to 36%). It is concluded that the reliability of the biceps brachii NIRS parameters during both sustained and repeated isometric contraction tasks is acceptable.

Effect of cold water immersion on repeated cycling performance and limb blood flow

The purpose of the present study was to compare the effects of cold water immersion (CWI) and active recovery (ACT) on resting limb blood flow, rectal temperature and repeated cycling performance in the heat. Ten subjects completed two testing sessions separated by 1 week; each trial consisted of an initial all-out 35-min exercise bout, one of two 15-min recovery interventions (randomised: CWI or ACT), followed by a 40-min passive recovery period before repeating the 35-min exercise bout. Performance was measured as the change in total work completed during the exercise bouts. Resting limb blood flow, heart rate, rectal temperature and blood lactate were recorded throughout the testing sessions. There was a significant decline in performance after ACT (mean (SD) −1.81% (1.05%)) compared with CWI where performance remained unchanged (0.10% (0.71%)). Rectal temperature was reduced after CWI (36.8°C (1.0°C)) compared with ACT (38.3°C (0.4°C)), as was blood flow to the arms (CWI 3.64 (1.47) ml/100 ml/min; ACT 16.85 (3.57) ml/100 ml/min) and legs (CW 4.83 (2.49) ml/100 ml/min; ACT 4.83 (2.49) ml/100 ml/min). Leg blood flow at the end of the second exercise bout was not different between the active (15.25 (4.33) ml/100 ml/min) and cold trials (14.99 (4.96) ml/100 ml/min), whereas rectal temperature (CWI 38.1°C (0.3°C); ACT 38.8°C (0.2°C)) and arm blood flow (CWI 20.55 (3.78) ml/100 ml/min; ACT 23.83 (5.32) ml/100 ml/min) remained depressed until the end of the cold trial. These findings indicate that CWI is an effective intervention for maintaining repeat cycling performance in the heat and this performance benefit is associated with alterations in core temperature and limb blood flow.

Emergence in games

The future direction of game development is towards more flexible, realistic, and interactive game worlds. However, current methods of game design do not allow for anything other than pre-scripted player exchanges and static objects and environments. An emergent approach to game development involves the creation of a globally designed game system that provides rules and boundaries for player interactions, rather than prescribed paths. Emergence in Games provides a detailed foundation for applying the theory and practice of emergence in games to game design. Emergent narrative, characters and agents, and game worlds are covered and a hands-on tutorial and case study allow the reader to the put the skills and ideas presented into practice.

Which way from here? The spatiality of maps & navigation in first-person single-player video games

Player experience of spatiality in first-person, single-player games is informed by the maps and navigational aids provided by the game. This project uses textual analysis to examine the way these maps and navigational aids inform the experience of spatiality in Fallout 3, BioShock and BioShock 2. Spatiality is understood as trialectic, incorporating perceived, conceived and lived space, drawing on the work of Henri Lefebvre and Edward Soja. The most prominent elements of the games’ maps and navigational aids are analysed in terms of how they inform players’ experience of the games’ spaces. In particular this project examines the in-game maps these games incorporate, the waypoint navigation and fast-travel systems in Fallout 3, and the guide arrow and environmental cues in the BioShock games.

Interacting constraints of defensive pressure and ball displacement trajectories shape locomotor pointing behaviours in association football

Performance of locomotor pointing tasks (goal-directed locomotion) in sport is typically constrained by dynamic factors, such as positioning of opponents and objects for interception. In the team sport of association football, performers have to coordinate their gait with ball displacement when dribbling and when trying to prevent opponent interception when running to kick a ball. This thesis comprises two studies analysing the movement patterns during locomotor pointing of eight experienced youth football players under static and dynamic constraints by manipulating levels of ball displacement (ball stationary or moving) and defensive pressure (defenders absent, or positioned near or far during performance). ANOVA with repeated measures was used to analyse effects of these task constraints on gait parameters during the run-up and cross performance sub-phase. Experiment 1 revealed outcomes consistent with previous research on locomotor pointing. When under defensive pressure, participants performed the run-up more quickly, concurrently modifying footfall placements relative to the ball location over trials. In experiment 2 players coordinated their gait relative to a moving ball significantly differently when under defensive pressure. Despite no specific task instructions being provided beforehand, context dependent constraints interacted to influence footfall placements over trials and running velocity of participants in different conditions. Data suggest that coaches need to manipulate task constraints carefully to facilitate emergent movement behaviours during practice in team games like football.

The market structure and characteristics of electronic games

A multi-billion dollar industry, electronic games have been experiencing strong and rapid growth in recent times. The world of games is not only exciting due to the magnificent growth of the industry however, but due to a host of other factors. This chapter explores electronic games, providing an analysis of the industry, key motivators for game play, the game medium and academic research concerning the effects of play. It also reviews the emerging relationship games share with sport, recognizing that they can replicate sports, facilitate sports participation and be played as a sport. These are complex relationships that have not yet been comprehensively studied. The current chapter serves to draw academic attention to the area and presents ideas for future research.

Mind games : applying White’s principles of narrative therapy to the creation of a cabaret about depression and bipolar disorder

This PhD represents my attempt to make sense of my personal experiences of depression through the form of cabaret. I first experienced depression in 2006. Previously, I had considered myself to be a happy and optimistic person. I found the experience of depression to be a shock: both in the experience itself, and also in the way it effected my own self image. These personal experiences, together with my professional history as a songwriter and cabaret performer, have been the motivating force behind the research project. This study has explored the question: What are the implications of applying principles of Michael White’s narrative therapy to the creation of a cabaret performance about depression and bipolar disorder? There is a 50 percent weighting on the creative work, the cabaret performance Mind Games, and a 50 percent weighting on the written exegesis. This research has focussed on the illustration of therapeutic principles in order to play games of truth within a cabaret performance. The research project investigates ways of telling my own story in relation to others’ stories through three re-authoring principles articulated in Michael White’s narrative therapy: externalisation, an autonomous ethic of living and rich descriptions. The personal stories presented in the cabaret were drawn from my own experiences and from interviews with individuals with depression or bipolar disorder. The cabaret focussed on the illustration of therapeutic principles, and was not focussed on therapeutic ends for myself or the interviewees. The research question has been approached through a methodology combining autoethnographic, practice-led and action research. Auto ethnographic research is characterised by close investigation of assumptions, attitudes, and beliefs. The combination of autoethnographic, practice-led, action research has allowed me to bring together personal experiences of mental illness, research into therapeutic techniques, social attitudes and public discourses about mental illness and forms of contemporary cabaret to facilitate the creation of a one-woman cabaret performance. The exegesis begins with a discussion of games of truth as informed by Michel Foucault and Michael White and self-stigma as informed by Michael White and Erving Goffman. These concepts form the basis for a discussion of my own personal experiences. White’s narrative therapy is focused on individuals re-authoring their stories, or telling their stories in different ways. White’s principles are influenced by Foucault’s notions of truth and power. Foucault’s term games of truth has been used to describe the effect of a ‘truth in flux’ that occurs through White’s re-authoring process. This study argues that cabaret is an appropriate form to represent this therapeutic process because it favours heightened performativity over realism, and showcases its ‘constructedness’ and artificiality. Thus cabaret is well suited to playing games of truth. A contextual review compares two major cabaret trends, personal cabaret and provocative cabaret, in reference to the performer’s relationship with the audience in terms of distance and intimacy. The study draws a parallel between principles of distance and intimacy in Michael White’s narrative therapy and relates these to performative terms of distance and intimacy. The creative component of this study, the cabaret Mind Games, used principles of narrative therapy to present the character ‘Jo’ playing games of truth through: externalising an aspect of her personality (externalisation); exploring different life values (an autonomous ethic of living); and enacting multiple versions of her identity (rich descriptions). This constant shifting between distance and intimacy within the cabaret created the effect of a truth in ‘constant flux’, to use one of White’s terms. There are three inter-related findings in the study. The first finding is that the application of principles of White’s narrative therapy was able to successfully combine provocative and empathetic elements within the cabaret. The second finding is that the personal agenda of addressing my own self-stigma within the project limited the effective portrayal of a ‘truth in flux’ within the cabaret. The third finding presents the view that the cabaret expressed ‘Jo’ playing games of truth in order to journey towards her own "preferred identity claim" (White 2004b) through an act of "self care" (Foucault 2005). The contribution to knowledge of this research project is the application of therapeutic principles to the creation of a cabaret performance. This process has focussed on creating a self-revelatory cabaret that questions notions of a ‘fixed truth’ through combining elements of existing cabaret forms in new ways. Two major forms in contemporary cabaret, the personal cabaret and the provocative cabaret use the performer-audience relationship in distinctive ways. Through combining elements of these two cabaret forms, I have explored ways to create a provocative cabaret focussed on the act of self-revelation.