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Melissa Hunfalvay and Nicholas Murray

The purpose of this study was to examine whether prior biped tennis playing experience results in different visual search strategies compared with no prior biped playing experience. A total of 32 wheelchair (WC) tennis players, 17 males and 15 females, ranked between 1 and 16 on the International Tennis Federation rankings participated in this study. Half the players had prior experience playing tennis as a biped player, and half had no prior experience in biped tennis. The athletes viewed 18 different serves from an expert WC player while their gaze was monitored using eye tracking. Results revealed significant differences between the groups in fixation duration and number of fixations. Differences were also found in fixation locations and durations across biomechanical phases of the serve. The WC only players had more fixations for shorter periods than did WC with biped players in the ritual phase. In the preparatory and execution phases, however, the WC only players had fewer fixations for longer duration than the WC with biped players. Results are discussed in terms of long-term memory structures, learning, and considerations when coaching and training WC tennis players.

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Nicholas P. Murray and Christopher M. Janelle

The purpose of this study was to examine the central tenets of the Processing Efficiency Theory (PET) in the context of a dual-task auto racing simulation. Participants were placed into either high or low trait-anxiety groups and required to concurrently undertake a driving task while responding to one of four target LEDs upon presentation of either a valid or an invalid cue located in the central or peripheral visual field. Eye movements and dual-task performance were recorded under baseline and competition conditions. Anxiety was induced by an instructional set delivered prior to the competition condition. Findings indicated that while there was little change in driving performance from baseline to competition, response time was reduced for the low-anxious group but increased for the high-anxious group during the competitive session. Additionally there was an increase in search rate for both groups during the competitive session, indicating a reduction in processing efficiency. Implications of this study include a more comprehensive and mechanistic account of the PET and confirm that increases in cognitive anxiety may result in a reduction of processing efficiency, with little change in performance effectiveness.

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Margaret P. Sanders and Nicholas P. Murray

The instructional environment of a self-defense program can influence skill acquisition, confidence, mood, and well-being. Two forms of learning responsible for the acquisition of a new motor skill is implicit and explicit learning. The purpose of the study was to evaluate a six-week implicit versus explicit self-defense training program on skill improvement, self-efficacy, affect, and subjective well-being. Thirty older adults were randomly assigned to one of two self-defense training groups, with one being taught implicitly and the other explicitly. A skill test was used to measure speed, accuracy, and effectiveness of self-defense skills learned. Participants were also assessed by a Self-Defense Self-Efficacy scale, PANAS-X, Personal Well-being Index-Adult, and Subjective Vitality scale. A repeated measure of ANOVA, post hoc test, and an independent samples t-test was used to evaluate each variable. Data analysis revealed that the implicit self-defense training group exhibited greater speed and accuracy in performing self-defense skills, while the explicit group demonstrated greater skill efficiency. Both training groups reported an increase in self-efficacy, positive affect, and subjective well-being. The findings of the study highlight the benefits of implicit instruction on self-defense training, and is unique to the older population.

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Nathan D. Dicks, Nicholas A. Jamnick, Steven R. Murray, and Robert W. Pettitt

Purpose:

To investigate a new power-to-body-mass (BM) ratio 3-min all-out cycling test (3MT%BM) for determining critical power (CP) and finite work capacity above CP (W ′).

Methods:

The gas-exchange threshold (GET), maximal oxygen uptake (VO2max), and power output evoking VO2max (W peak) and GET (W GET) for cycle ergometry were determined in 12 participants. CP and W′ were determined using the original “linear factor” 3MT (3MTrpm^2) and compared with CP and W′ derived from a procedure, the 3MT%BM, using the subject’s body mass and self-reported physical activity rating (PA-R), with values derived from linear regression of the work–time model and power–inverse-time model (1/time) data from 3 separate exhaustive squarewave bouts.

Results:

The VO2max, VO2GET, W peak, and W GET values estimated from PA-R and a non-exercise-regression equation did not differ (P > .05) from actual measurements. Estimates of CP derived from the 3MT%BM (235 ± 56 W), 3MTrpm^2 (234 ± 62 W), work–time (231 ± 57 W), and 1/time models (230 ± 57 W) did not differ (F = 0.46, P = .72). Similarly, estimates of W′ between all methods did not differ (F = 3.58, P = .07). There were strong comparisons of the 3MT%BM to 1/time and work–time models with the average correlation, standard error of the measurement, and CV% for critical power being .96, 8.74 W, and 4.64%, respectively.

Conclusion:

The 3MT%BM is a valid, single-visit protocol for determining CP and W′.

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Christopher M. Janelle, Charles H. Hillman, Ross J. Apparies, Nicholas P. Murray, Launi Meili, Elizabeth A. Fallon, and Bradley D. Hatfield

The purpose of this study was to examine whether variability in gaze behavior and cortical activation would differentiate expert (n = 12) and nonexpert (n = 13) small-bore rifle shooters. Spectral-activity and eye-movement data were collected concurrently during the course of a regulation indoor sequence of 40 shots from the standing position. Experts exhibited significantly superior shooting performance, as well as a significantly longer quiet eye period preceding shot execution than did nonexperts. Additionally, expertise interacted with hemispheric activation levels: Experts demonstrated a significant increase in left-hemisphere alpha and beta power, accompanied by a reduction in right-hemisphere alpha and beta power, during the preparatory period just prior to the shot. Nonexperts exhibited similar hemispheric asymmetry, but to a lesser extent than did experts. Findings suggest systematic expertise-related differences in ocular and cortical activity during the preparatory phase leading up to the trigger pull that reflects more optimal organization of the neural structures needed to achieve high-level performance.

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Gustavo Sandri Heidner, Patrick M. Rider, J.C. Mizelle, Caitlin M. O’Connell, Nicholas P. Murray, and Zachary J. Domire

Virtual reality (VR) paradigms have proved to be a valid method to challenge and perturb balance. There is little consensus in the literature on the best protocol design to perturb balance and induce postural sway. Current VR interventions still lack a well-defined standardized metric to generate a virtual environment that can perturb balance in an efficacious, lifelike, and repeatable manner. The objective of this study was to investigate different configurations of amplitude and frequency in an anterior–posterior translation VR environment, that is, lifelike and scaled. Thirteen young adults with no conditions affecting balance were recruited. Balance was challenged by anterior–posterior sinusoidal movement of the lab image within the VR headset. Four different amplitudes of the sinusoidal movement were tested: 1, 5, 10, and 20 cm, with each amplitude being presented at 2 test frequencies : 0.5 and 0.25 Hz. Mean center of pressure velocity was significantly greater than baseline at 0.5 Hz and amplitudes of 10 and 20 cm. Mean center of pressure at approximate entropy was greater than baseline at 0.5 Hz and amplitude of 20 cm. The results suggest that sinusoidal movement of a realistic VR environment produces altered balance compared with baseline quiet standing, but only under specific movement parameters.