The ability to react following the processing and integration of relevant visual cues within a changing environment is a key determinant of sporting success (Adam et al., 1992). Individuals who possess the ability to process a greater amount of visual information in a shorter period of time may have a competitive advantage over their slower counterparts (Spiteri et al., 2013), allowing for the facilitation of both decision making ability (Mori et al., 2002), and motor response time (Ando et al., 2001). Consequently, the ability to reliably assess reaction time (RT) may support the evaluation of athletic ability.
To date, several laboratory assessments have been utilized to evaluate and quantify changes in RT performance (Ando et al., 2001; Hoffman et al., 2010; 2012; Hultsch et al., 2002; Li et al., 2000; Mori et al., 2002; Schatz et al., 2006; Stuss et al., 1989; Williams et al., 2005). Acute changes in RT performance are commonly quantified with finger tapping tests, simple reaction time (SRT) tests and/or choice reaction time tests (CRT) via a computer integrated; touch sensitive, visual light system. Such tests have also been administered in conjunction with a battery of other psychological tests to aid in the quantification of changes in cognitive performance (Schatz et al., 2006; Williams et al., 2005). However, information regarding the reliability of many of these reaction tests is lacking. The internal test-retest reliability of reaction devices are rarely reported in the literature, while emerging reliability studies on RT test devices show unacceptable (
Recently, the Dynavision[TM] D2 Visuomotor Training Device (D2) has emerged as a tool in the assessment of RT (Hoffman et al., 2012; Wells et al., 2013). The D2 is a light-training reaction device, developed to train sensory motor integration through the visual system (Wells et al., 2013). In addition to high performance training and evaluation, the D2 is also marketed as a standard device for neuro-rehabilitation, stroke recovery, and concussion evaluation. It is also used to assess visual and motor reaction to both central and peripheral stimuli, with a capacity to integrate increasing levels of cognitive challenges.
Previous studies utilizing the D2 have shown high intraclass correlation coefficients (ICC's; 0.79-0.97) in a number of tests of varying complexity, indicating strong test-retest reliability (Klavora et al., 1995; Wells et al., 2013). In addition, strong correlations with conventional psychomotor tests demanding similar visuomotor skills and psychomotor ability have also been demonstrated (Vesia et al., 2008). However; to our knowledge, these studies have not been repeated. In addition, all prior studies have utilized either ICC version 3,1 or declined to delineate the ICC version utilized (Klavora et al., 1994; 1995; Wells et al., 2013). As such, reliability data for the D2 generated from these studies is not generalizable beyond the confines of that study since the effect of trials is either fixed or unknown (Weir, 2005). Therefore, the purpose of this study was to establish the reliability of three D2 RT tasks utilizing ICC version 2,1 ([ICC.sub.2,1]), which considers the effect of trials to be a random factor since the trials are a sample of possible levels.
Forty-two recreationally active individuals (22 men, 20 women) volunteered to participate in this study (n = 42; age: 23.41 [+ or -] 4.84 years; height: 1.72 [+ or -] 0.11 m; mass: 76.62 [+ or -] 18.26 Kg; body fat %: 19.46 [+ or -] 8.90). The research protocol was approved by the University Institutional Review Board. Following an explanation of all procedures, risks, and benefits associated with the experimental protocol, each participant gave his or her informed consent to participate in this study. Participants were healthy college students with no prior experience with the test apparatus. All participants reported having no vision problems, other than that correctable with prescription lenses. Prescription lenses (glasses and/or contact lenses) were permitted. Use of prescriptive lenses was standardized across test sessions. Participants were also instructed not to consume caffeine at least 5 hours prior to testing. This was verbally confirmed prior to each test session, and again at the conclusion of the experimental protocol.
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Participants reported to the Human Performance Laboratory (HPL) on six separate occasions, with at least 48 hours between each session. During each of the six sessions, participants completed three consecutive visuomotor tasks of increasing complexity. Reaction time was assessed using the Dynavision[TM] D2 Visuomotor Training Device (D2; Dynavision International LLC, West Chester, OH). The D2 device was previously described (Wells et al., 2013). Briefly, the D2 is a light-training reaction device, developed to train sensory motor integration through the visual system (see Figure 1). It consists of a board (4 x 4 ft.) that can be raised or lowered relative to the height of the participant. The board contains 64 target buttons arranged into five concentric circles that can be illuminated to serve as a stimulus for the participant, and contains an LCD display above the inner most ring of target buttons. The LCD display is utilized to place a cognitive stressor on the participant during testing and provide a 5 s visual countdown to the start of a test.
Upon arriving at the HPL for the first visit, participants were familiarized with the D2, and were provided detailed verbal instructions on both the testing protocol and how to complete each of the three tasks from a standardized script. For each task, participants were instructed to take an athletic stance, consisting of flexed knees, low center of gravity and upright posture. The D2 board was then raised or lowered to the height of the participant, such that the LCD screen was approximately at eye level, and the outer-most target buttons were within hands reach. Following verbal instruction, participants completed a shortened practice trial of each test. Upon completion of the...