Modeling Gambling: An Application of the Mathematical Principles of Reinforcement

The Mathematical Principles of Reinforcement (MPR) has proved a useful model for predicting and describing the behaviour of non-human animals on different schedules of reinforcement. This research tests the ability of MPR to accurately predict performance of adult humans on a simulated gambling task. A simulated electronic gaming machine was used in three experiments and gambling responses were reinforced according to series of Random Ratio schedules. In Experiment 1, when participants experienced either an ascending or descending order of ratios, rates of responding were well described by a bitonic response gradient. In Experiments 2 and 3 participants experienced either an early large win or an early large loss before experiencing a series of ratio schedule values that were presented in ascending order. Again rates of responding, expressed as a function of ratio schedule value, were well described by a bitonic response gradient. The early large loss condition produced higher response rates than the early large win condition. The bitonic response gradients of all conditions were well described by MPR via changes in the parameter a, specific activation

Incidence, severity, aetiology and type of neck injury in men's amateur rugby union: a prospective cohort study

<p>Abstract</p> <p>Background</p> <p>There is a paucity of epidemiological data on neck injury in amateur rugby union populations. The objective of this study was to determine the incidence, severity, aetiology and type of neck injury in Australian men's amateur rugby union.</p> <p>Methods</p> <p>Data was collected from a cohort of 262 participants from two Australian amateur men's rugby union clubs via a prospective cohort study design. A modified version of the Rugby Union Injury Report Form for Games and Training was used by the clubs physiotherapist or chiropractor in data collection.</p> <p>Results</p> <p>The participants sustained 90 (eight recurrent) neck injuries. Exposure time was calculated at 31143.8 hours of play (12863.8 hours of match time and 18280 hours of training). Incidence of neck injury was 2.9 injuries/1000 player-hours (95%CI: 2.3, 3.6). As a consequence 69.3% neck injuries were minor, 17% mild, 6.8% moderate and 6.8% severe. Neck compression was the most frequent aetiology and was weakly associated with severity. Cervical facet injury was the most frequent neck injury type.</p> <p>Conclusions</p> <p>This is the first prospective cohort study in an amateur men's rugby union population since the inception of professionalism that presents injury rate, severity, aetiology and injury type data for neck injury. Current epidemiological data should be sought when evaluating the risks associated with rugby union football.</p