Concussions are an area of concern in the health care community. It is estimated that more than 8 million high school athletes participate in athletic activity annually, making them the single largest athletic cohort in the country.1 Commensurate with increasing participation in high school athletic programs, the frequency of sports-related concussions (SRCs) is increasing. Recent data from the United States suggest that 1.1 to 1.9 million2 SRCs occur annually in individuals aged 18 years and younger. Approximately 15% of all high school sports-related traumas are concussions.3,4
Dizziness, reported by approximately half of high school athletes who suffered a concussion, has been associated with protracted recovery.5,6 Dizziness may also be associated with poor vestibular and oculomotor integration. Thus, it is important to evaluate for oculomotor and visual deficits (eg, blurred vision, diplopia, eye strain, and poor eye tracking) following injury.7 These symptoms are associated with vergence and accommodation dysfunction.8 Oculomotor dysfunction has been identified in up to 65% of patients following a concussion.9
When visual and vestibular dysfunctions are reported concurrently following a concussion, patients demonstrate reaction time deficits,10 which may lead to longer recovery times.11,12 Studies report that reaction time deficits are generally present immediately following a concussion and gradually return to normal throughout recovery.13,14 Although reaction time deficits may present with other vestibular-related concussion symptoms, some patients continue to show reaction time impairments even in the absence of other symptoms.14,15 Clinicians should understand the importance of reaction time deficits in athletes and how to objectively assess reaction time following a concussion and serially throughout the recovery period.
Multiple studies have investigated the recovery trajectories of cognition, symptoms, and balance following a concussion.16–18 However, few studies have investigated reaction time function following a concussion,11,19,20 especially in the adolescent population. Concussion assessment tools are commonly used to assess symptom reports following concussion. Computerized neurocognitive tests21 and the ruler drop stick test may be used to assess visual reaction time.22 However, more sophisticated reaction time measurements are needed to evaluate motor output, hand–eye coordination, and peripheral vision deficits. To create a multimodal approach following a concussion, diverse areas of reaction time and visual function should be assessed.
The Dynavision D2 light board (Dynavision International LLC) provides an objective means to assess reaction time and visuomotor response.23 This device creates customizable protocols that may be used to assess and train reaction time.23 The Dynavision D2 (Figure 1) consists of 64 raised target buttons, which are arranged in five rings and broken into four quadrants (upper left, upper right, lower left, and lower right), and a centralized tachistoscope (T-scope) LED screen (central display box).23 The device enables users to measure reaction time, hits per minute, visual, motor, and physical reaction times, and overall response patterns.23 Computerized devices such as the Dynavision D2 provides tools for a more precise assessment of visual-motor reaction time for sports vision training programs and concussion assessment battery. Previous studies have reported the test–retest reliability of Dynavision D2 protocols to be reliable in healthy adults and recreational athletes when assessing neuromuscular reactivity and cognitive load with ICC values ranging from 0.75 to 0.92.23–25
The Dynavision D2 light board (Dynavision International LLC).
As with all concussion assessments that are administered serially, understanding test–retest reliability and the potential for practice effects is important for the appropriate interpretation of data.26 Strong reliability will allow clinicians to attribute fluctuations in scores to the progression or regression of patient status rather than error produced by the measurement process.26 Poor or unknown reliability reduces the utility of a measurement, which affects the clinician's ability to accurately interpret changes in test performance over time.26 To date, no studies have investigated reaction time in the adolescent population using the Dynavision D2 for concussion assessment or serially following injury. Before this line of research can be pursued, reaction time assessments must be studied to evaluate reliability. Reliability studies should be conducted prior to incorporating visual-motor reaction time assessments using the Dynavision D2 in clinical practice. Therefore, the purpose of this study was to evaluate the test–retest reliability and practice effects of the Dynavision D2 reaction time tests in healthy high school athletes.
Thirty-two healthy adolescent athletes participated in this study. Prior to participation, individuals were screened to ensure they met study inclusion criteria, which were individuals between 15 and 18 years old who actively participated in sports. Individuals were excluded if they were diagnosed as having a concussion within the past 3 months or were currently being treated for vestibular, visual, or balance disorders. These exclusion criteria were intended to preclude any confounding effects due to lingering concussion symptoms. Participants and parents or guardians, when appropriate, completed assent and permission forms prior to participation. The study was approved by A.T. Still University's institutional review board.
A brief three-question medical questionnaire was completed by each participant to identify current medical conditions, concussion history, and diagnosis of vestibular or balance disorder. The following are questions from the medical questionnaire:
Are you currently being treated for a medical condition? Yes or no. If yes, please list.
Have you ever been diagnosed with a concussion? Yes or no. If yes, how long ago was your last concussion?
Have you ever been diagnosed with a vestibular/balance disorder? Yes or no. If yes, please explain.
Participants completed two testing sessions 1 week apart (session 1 and session 2) using the Dynavision D2 system. The first session comprised one familiarization trial and two test trials. One week later, the second session comprised two test trials. Each trial consisted of nine total Dynavision D2 tests. Participants rested for 2 to 3 minutes between each trial and 30 to 45 seconds between individual tests. Figure 2 depicts a flow chart of each trial and test. Table 1 provides each test name and the associated dependent variable. Prior to starting testing, the participant was instructed to stand centrally in front of the Dynavision D2 at a distance of an arm's length. This distance was measured in inches and recorded in the participant's file. The average distance from the participant's acromion processes to the light board was 28.2 ± 2.2 inches. The Dynavision D2 height was adjusted based on the participant's height, aligning the inferior aspect of the central display box on the Dynavision D2 with the tip of the participant's nose.
Flow chart of the testing protocol used to demonstrate trials 1–5.
Characteristics of the Tests Used on the Dynavision D2
Mode A (Reactive Mode)
The Dynavision D2 Mode A is a reactive mode. Each individual Dynavision D2 Mode A test was performed for 1 minute. During the test, a single, red illuminated target would appear within the five display rings. Participants deactivated the light by striking it, and another light would be illuminated in a random location. This cycle continued until the test ended and assessed how reactive the participants were at deactivating the lights. Participants were instructed to strike as many red illuminated targets as quickly as possible in 60 seconds. The hits per minute and average reaction time were recorded. Participants completed this test three times in a single trial. For session 1, the participants completed Mode A for three trials (three tests per trial). For session 2, the participants completed Mode A for two trials (three tests per trial) for a total of 15 tests.
Choice Reaction Tests
Following the Dynavision D2 Mode A test, participants completed a series of eight reaction time tests: right and left hand four choice, eight choice, central vision one choice, and peripheral vision one choice. The four choice reaction test consisted of a linear line of targets with four potential random options, whereas the eight choice appeared along an arc of a circle in an area of eight different targets. The central vision and peripheral vision one choice tests are simple choice tests because they only use one light. Each test consisted of six separate strikes of the red illuminated target. There is no time limit in the reaction test mode. At the conclusion of each test, physical, motor, and visual reaction time scores were generated. Visual reaction time was measured as the amount of time it took to identify the stimulus and initiate a reaction by leaving the “home” button.24 Motor reaction time was measured as the amount of time (measured in 1/100 of a second) it took to physically strike the illuminated button following the initial visual reaction.24 For each separate choice reaction test, the left and right hand visual and motor reaction time scores were combined and averaged.
Choice Reaction Test Four/Eight/Central Vision One Choice
For four choice reaction time, participants were centrally facing the Dynavision D2 with a linear row of targets briefly illuminated, indicating the direction of the target area. The number of illuminated targets was determined by testing either the four or one choice test. For choice eight, a random target along an arc of a circle was illuminated. Participants were first instructed to use their right hand to extinguish targets that illuminated on the left side of the central display box, thus performing a cross-body strike, and then repeat the same process with the left hand. To begin the test, participants used their right hand to strike the left-sided, red illuminated target as quickly as possible and then return it to the original “home” button. This test consisted of six separate strikes for each trial. The same procedure was used for choice four, eight, and central vision one choice testing of the right hand and left hand with a different number of targets illuminated.
Choice Reaction Test Peripheral Vision One Choice
For this peripheral vision one choice test only, the participants were instructed to take one step to the right, centering their nose under the first target directly to the right of the central display box. In this off-centered starting position, a single button just to the left of the central display box briefly illuminated to display the target area. The first red-lighted “home” button appeared on the participants' right side. After seeing the target area illuminate, they were told to perform a cross-body movement and strike the target on their left side with their right hand as quickly as possible and return to the “home” button. This test was performed for a total of six targets per trial. The same procedure was performed for peripheral vision one choice left hand.
SPSS software (version 25; IBM Inc) was used for statistical analysis. Mode A scores included average hits per minute and average reaction time for each trial. A total of 15 Mode A scores were used for analysis. Scores for the choice reaction tests (four choice, eight choice, central vision one choice, and peripheral vision one choice) were calculated for each session (session 1 and session 2) by averaging the left and right-handed test scores to generate a single average for visual and motor reaction time. The within-days (within-day 1 and within-in day 2) and between-days average test–retest reliabilities were analyzed using two-way random effects, consistent with intraclass correlation coefficients (ICCs). The within-days analysis assessed trials conducted within each day (day 1 and day 2), whereas the between-days analysis assessed reliability between tests performed on the two testing days.
The standard error of measurement (SEM) and minimal detectable change (MDC) scores were calculated for all choice reaction tests. SEM values were calculated as: SEM = SD × √(1 – ICC). MDC, which estimates the magnitude of change necessary to provide confidence that a change is not the result of random variation or measurement error, was calculated as MDC = z-score (90% confidence interval [CI]) × SEM × √2.27 An ICC value of greater than .90 was considered excellent, between .75 and .90 was good, between .50 and .75 was moderate, and less than .50 was considered poor reliability.28
Practice effects were analyzed with repeated measures analysis of variance and Helmert contrasts (P < .05). The Helmert contrast compares the mean of each level of the factor (except the last) to the mean of subsequent levels. Dependent variables included hits per minute and average reaction time for Mode A and visual-motor reaction times for choice reaction tests four choice, eight choice, central vision one choice, and peripheral vision one choice.
Thirty-two healthy adolescent athletes (20 females, 12 males; age = 16.2 ± 1.2 years, mass = 67.0 ± 17.0 kg, height = 171.3 ± 10.3 cm) participated in the study. Twenty-nine participants (91%) were right-handed and 13 participants (40.6%) reported having corrected vision (glasses or contacts). Additionally, 11 participants (34.4%) had a self-reported concussion history of concussion, but not in the past 3 months.
Excellent (ICC: 0.92 to 0.95) and good to excellent (ICC: 0.78 to 0.92) reliabilities were demonstrated for hits per minute and average reaction time, respectively, during Mode A (Table 2). Means and standard deviations by trial for Mode A are found in Table 3. Practice effects were noted for hits per minute within all trials and for average reaction time within-trial 1 and 2 versus later (P < .001), and within-trial 4 versus 5 (P = .014) (Table 3). Helmert contrasts suggested that the practice effect did not demonstrate a plateau at any point during the trials for hits per minute or average reaction time (Table 3). Mean differences exceeded MDC values for between day hits per minute and average reaction time only (Table 2).
Reliability Data for Mode A
Mode A and CRT Mean ± SD for Hits/Minute, AvgRT, and CRT Within Each Trial and Helmert Contrasts
Choice Reaction Tests
Four Choice. Visual four choice reaction time yielded good-to-excellent reliability (ICC: 0.79 to 0.90), whereas motor four choice reaction time yielded poor-to-moderate reliability (ICCs: 0.49 to 0.70) (Table 4). Practice effects were found only for visual four choice reaction time within-trial 1 versus later (P < .001) (Table 3). Mean differences between trials did not exceed reported MDC values (Table 4).
Reliability Data for CRT, ICC Value 95% CI (Lower Bound, Upper Bound), SEM, and MDC
Eight Choice. Visual eight choice reaction time yielded poor reliability for within-day 1 and between-days (ICC: 0.36 to 0.49), whereas visual eight choice reaction time for within-day 2 yielded moderate reliability (ICC = 0.70) (Table 4). Motor eight choice reaction time also demonstrated moderate reliability for within-day 1 and between-days (ICCs: 0.66, 0.69), whereas it yielded poor reliability for within-day 2 (ICC = 0.17). Practice effects were only present within motor eight choice reaction time trial-two versus later (P < .001) (Table 3). Mean differences between trials did not exceed reported MDC scores (Table 4).
Central Vision One Choice. Central vision one choice visual and motor reaction time demonstrated good reliability (ICC: 0.81 to 0.89) (Table 4). Practice effects were only present for central vision one choice motor reaction time trial-3 versus later (P = .011) (Table 3). Mean differences between trials did not exceed reported MDC scores (Table 4).
Peripheral Vision One Choice. Peripheral vision one choice visual reaction time yielded moderate-to-good reliability (ICC: 0.59 to 0.84). Peripheral vision one choice motor reaction time within-day 1 and between-days yielded moderate -reliability (ICCs: 0.69 to 0.74), whereas within-day 2 yielded moderate reliability (ICC = 0.55) (Table 4). Practice effects were not noted for this test (Table 3). Mean differences between trials did not exceed reported MDC scores (Table 4).
The aim of the study was to estimate Dynavision D2 test–retest reliability in healthy adolescent athletes. Findings suggest that most Dynavision D2 tests can reliably assess reaction time within this population under specific scenarios. Higher reliability values were produced within Mode A, four choice visual, and central one choice reaction time. Substantially lower reliability values were produced for more complex tests such as eight choice visual and motor reaction time and peripheral one choice reaction time. Clinicians should use caution when interpreting test results due to the presence of practice effects that were observed in both Mode A and the choice reaction tests.
Findings from the current study established similar reliabilities as other studies found using the Dynavision D2 system.23,24,29 Specifically, the Dynavision D2 Mode A task hits per minute demonstrated consistent between-day good-to-excellent reliability (ICC = 0.92), similar to Klavora et al29 and Wells et al24 (ICC = .88 and .75, respectively). Further, the Mode A task average reaction time task yielded excellent between-day reliability (ICC = 0.90) consistent with findings from Picha et al23 (ICC = 0.88),23 and greater than Wells et al24 (ICC = 0.68).
Improved reaction times during Mode A were observed through all trials and increased hits per minute were observed through trials 1 to 3 and then again between trials 4 and 5, suggesting significant practice effects or a learning curve. This indicates the need for up to five familiarization trials for Mode A and at least three familiarization trials for the choice reaction tests prior to conducting a baseline assessment so practice-related improvements may be attenuated. The high reliability that was identified in this study and others23,24,29 is encouraging because it allows clinicians to attribute fluctuations in scores to the patient presentation rather than measurement error. However, it is also important to correlate improvements in generated scores to the improvements in the overall well-being of the patient. Therefore, mitigating practice effects via the use of familiarization trials is vital.
The variation in timing between sessions and familiarization protocols may account for the fluctuation observed in reported ICC values and learning effects. It may be that 48 hours between testing sessions is not enough time to diminish carryover or practice effects, as Wells et al24 yielded the lowest average between day reliability (ICC = .68). Allowing for 1 to 2 weeks between testing sessions may yield more reliable results, as seen in the current study and the studies by Picha et al23 and Klavora et al.29 This may allow enough time between testing sessions to produce optimal results, decreasing the chance of carryover and practice effects. The timing of testing may impact participants' overall score, thus affecting the reliability of the Dynavision D2. Repetitive testing with little recovery time could negatively affect scores due to fatigue and loss of interest. Longer recovery times may allow for greater concentration and a reduced chance of carryover effects.29,30
Ideally, moderate-to-high reliability should be observed across all tasks on the Dynavision D2. However, the variation in reliability estimates may be attributed to the fact that the Dyanvision D2 Mode A test was performed more than three times as frequently as the choice reaction tests. This may have contributed to better reliability in the Mode A test–retest reliability. Although the performance complexity for the choice reaction tests was less than that for Mode A, participants did not have as much opportunity for improvement. The length of time it took to conduct each testing session and maintaining adolescent concentration and enthusiasm proved to be a challenge. Lower choice reaction test reliability values may also be attributed, in part, to anticipatory factors, causing an impulsive or inaccurate release of the “home” button prior to the target button illuminating. This factor was observed during the current study but has not been specifically addressed in similar studies because the choice reaction tests have not yet been studied in the adolescent population.
Although the use of certain tasks, specifically Mode A, for the Dynavision D2 is supported by reliability estimates, this study was not without limitations. Females comprised approximately two-thirds of the sample. Optimally, males and females would have been equally represented, but we were unable to balance participants by sex, so our results more accurately represent female than male athletes. The familiarization protocol chosen may influence the reliability of test results. Increasing the number of familiarization trials beyond what has been previously studied may result in training effects. Although this study yielded acceptable ICC values for reaction time (visual and motor) and average hits per minute, the likelihood of having fully dissipated the effects of learning is unknown, thus hindering the ability to identify where a true baseline score lies.24 It is also important to consider limitations such as cost and feasibility. The Dynavision D2 may not be heavily implemented into everyday clinical practice at the high school level, making it important to compare the Dynavision D2 to other more accessible tools. However, the newly established reliability values are important because there are few other tools that assess visual reaction time with a high level of precision and no tools that objectively assess peripheral vision deficits. As noted earlier, the ruler drop test is an additional method of assessing simple reaction time. However, as with the Dynavision D2 and other concussion assessment tools, this test is susceptible to practice effects.22 However, the test–retest reliabilities of both the simple and complex versions of the ruler drop test are acceptable (ICC = .76 and .79, respectively).31 The complex modification of this test includes an additional task of watching a light stimulus to determine whether or not the dropped ruler is to be caught.31 Of course, the reliability of the ruler drop test does not necessarily translate to functional sport skills or the reaction time to motor output required for higher-level competition. However, the Dynavision D2 can be used for sports training and has developed more functional testing with position-specific skills allowing for a more realistic transition to return to play.
Implications for Clinical Practice
The results from this study suggest that the Dynavision D2 reliably assesses reaction time under certain scenarios in healthy adolescents. The high test–retest reliability for Mode A may help clinicians to identify subtle changes in reaction time. These findings demonstrate the reliability in a healthy population for specific reaction time tasks, and provide an opportunity to further assess utility in injured patients. Future research should be conducted to assess factors such as lingering visual-motor deficits and concussion recovery patterns in the injured adolescent population. Whether used serially, before or after injury, or as a training tool, clinicians should be aware of the potential for practice effects and take precautions to reduce their overall impact. However, on a cautionary note, an astute reviewer of an earlier version of this manuscript noted that a participant with concussion may experience exacerbated symptoms while having to perform tasks multiple times for familiarization. Further research should be conducted to assess value in use for patients with concussion and if the Dynavision D2 should be implemented as a post-injury protocol.
- High School Sports Participation Increased for 28th Straight Year, Nears 8 Million Mark National Federation Of State High School Associations. 2017. https://www.nfhs.org/articles/high-school-sports-participation-increases-for-28th-straight-year-nears-8-million-mark/
- Bryan MA, Rowhani-Rahbar A, Comstock RD, Rivara FSeattle Sports Concussion Research Collaborative. Sports- and recreation-related concussions in US youth. Pediatrics. 2016;138(1):e20154635. doi:10.1542/peds.2015-4635 [CrossRef]
- Dompier TP, Kerr ZY, Marshall SW, et al. Incidence of concussion during practice and games in youth, high school, and collegiate american football players. JAMA Pediatr. 2015;169(7):659–665. doi:10.1001/jamapediatrics.2015.0210 [CrossRef]
- Meehan WP III, d'Hemecourt P, Collins CL, Comstock RD. Assessment and management of sport-related concussions in United States high schools. Am J Sports Med. 2011;39(11):2304–2310. doi:10.1177/0363546511423503 [CrossRef]
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- Collins MW, Kontos AP, Reynolds E, Murawski CD, Fu FH. A comprehensive, targeted approach to the clinical care of athletes following sport-related concussion. Knee Surg Sports Traumatol Arthrosc. 2014;22(2):235–246. doi:10.1007/s00167-013-2791-6 [CrossRef]
- Ciuffreda KJ, Kapoor N, Rutner D, Suchoff IB, Han ME, Craig S. Occurrence of oculomotor dysfunctions in acquired brain injury: a retrospective analysis. Optometry. 2007;78(4):155–161. doi:10.1016/j.optm.2006.11.011 [CrossRef]
- Capó-Aponte JE, Urosevich TG, Temme LA, Tarbett AK, Sanghera NK. Visual dysfunctions and symptoms during the subacute stage of blast-induced mild traumatic brain injury. Mil Med. 2012;177(7):804–813. doi:10.7205/MILMED-D-12-00061 [CrossRef]
- Clark JF, Ellis JK, Burns TM, Childress JM, Divine JG. Analysis of central and peripheral vision reaction times in patients with post-concussion visual dysfunction. Clin J Sport Med. 2017;27(5):457–461. doi:10.1097/JSM.0000000000000381 [CrossRef]
- Eckner JT, Kutcher JS, Broglio SP, Richardson JK. Effect of sport-related concussion on clinically measured simple reaction time. Br J Sports Med. 2014;48(2):112–118. doi:10.1136/bjsports-2012-091579 [CrossRef]
- Lau B, Lovell MR, Collins MW, Pardini J. Neurocognitive and symptom predictors of recovery in high school athletes. Clin J Sport Med. 2009;19(3):216–221. doi:10.1097/JSM.0b013e31819d6edb [CrossRef]
- Collie A, Makdissi M, Maruff P, Bennell K, McCrory P. Cognition in the days following concussion: comparison of symptomatic versus asymptomatic athletes. J Neurol Neurosurg Psychiatry. 2006;77(2):241–245. doi:10.1136/jnnp.2005.073155 [CrossRef]
- Warden DL, Bleiberg J, Cameron KL, et al. Persistent prolongation of simple reaction time in sports concussion. Neurology. 2001;57(3):524–526. doi:10.1212/WNL.57.3.524 [CrossRef]
- McClincy MP, Lovell MR, Pardini J, Collins MW, Spore MK. Recovery from sports concussion in high school and collegiate athletes. Brain Inj. 2006;20(1):33–39. doi:10.1080/02699050500309817 [CrossRef]
- Broglio SP, Puetz TW. The effect of sport concussion on neurocognitive function, self-report symptoms and postural control : a meta-analysis. Sports Med. 2008;38(1):53–67. doi:10.2165/00007256-200838010-00005 [CrossRef]
- Broglio SP, Collins MW, Williams RM, Mucha A, Kontos AP. Current and emerging rehabilitation for concussion: a review of the evidence. Clin Sports Med. 2015;34(2):213–231. doi:10.1016/j.csm.2014.12.005 [CrossRef]
- Feddermann-Demont N, Echemendia RJ, Schneider KJ, et al. What domains of clinical function should be assessed after sport-related concussion? A systematic review. Br J Sports Med. 2017;51(11):903–918. doi:10.1136/bjsports-2016-097403 [CrossRef]
- Galetta KM, Brandes LE, Maki K, et al. The King-Devick test and sports-related concussion: study of a rapid visual screening tool in a collegiate cohort. J Neurol Sci. 2011;309(1–2):34–39. doi:10.1016/j.jns.2011.07.039 [CrossRef]
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- MacDonald J, Wilson J, Young J, et al. Evaluation of a simple test of reaction time for baseline concussion testing in a population of high school athletes. Clin J Sport Med. 2015;25(1):43–48. doi:10.1097/JSM.0000000000000096 [CrossRef]
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- Wells AJ, Hoffman JR, Beyer KS, et al. Reliability of the Dynavision™ D2 for assessing reaction time performance. J Sports Sci Med. 2014;13(1):145–150.
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Characteristics of the Tests Used on the Dynavision D2a
|Test||No. of Tests/Trials||No. of Strikes/Tests||Dependent Variable Measured|
|Mode A||3 drills||Maximum hits/minute||Hits/minute, average reaction time|
|CRT four choice||1 test||6||Visual and motor average reaction time|
|CRT eight choice||1 test||6||Visual and motor average reaction time|
|CRT central vision one choice||1 test||6||Visual and motor average reaction time|
|CRT peripheral vision one choice||1 Test||6||Visual and motor average reaction time|
Reliability Data for Mode Aa
|Parameter||Within-Day 1||Within-Day 2||Between Days|
|Avg hits/minute||.92 (.84 to .96)||1.32||3.07||.95 (.90 to .98)||1.21||2.81||.93 (.82 to .96)||1.24||2.87|
|AvgRT||.92 (.83 to .96)||0.01||0.03||.78 (.54 to .90)||0.02||0.05||.90 (.80 to .96)||0.01||0.04|
Mode A and CRT Mean ± SD for Hits/Minute, AvgRT, and CRT Within Each Trial and Helmert Contrasts
|Mode A Test||Mean ± SD T1||Mean ± SD T2||Mean ± SD T3||Mean ± SD T4||Mean ± SD T5||Helmert Contrast|
|Hits/minute||73.91 ± 4.97||77.90 ± 5.93||80.48 ± 5.63||80.87 ± 6.18||83.22 ± 6.95||T1 vs Later (P < .001)|
|T2 vs Later (P < .001)|
|T3 vs Later (P = .028)|
|T4 vs T5 (P < .001)|
|AvgRT (sec)||.81 ± .05||.77 ± .06||.74 ± .05||.75 ± .09||.72 ± .06||T1 vs Later (P < .001)|
|T2 vs Later (P < .001)|
|T3 vs Later (P = .176)|
|T4 vs T5 (P = .014)|
| Four visual||.38 ± .05||.35 ± .04||.35 ± .03||.35 ± .03||.34 ± .03||T1 vs Later (P < .001)|
| Four motor||.34 ± .07||.32 ± .07||.34 ± .07||.34 ± .07||.32 ± .07||N/A|
| Eight visual||.47 ± .08||.47 ± .13||.44 ± .08||.44 ± .08||.44 ± .09||N/A|
| Eight motor||.36 ± .08||.37 ± .07||.34 ± .06||.31 ± .06||.34 ± .10||T2 vs Later (P < .001)|
| CV one visual||.32 ± .03||.33 ± .04||.33 ± .04||.33 ± .04||.33 ± .04||N/A|
| CV one motor||.26 ± .07||.27 ± .07||.28 ± .07||.25 ± .06||.26 ± .06||T3 vs Later (P = .011)|
| PV one visual||.37 ± .06||.36 ± .05||.36 ± .05||.34 ± .04||.35 ± .04||N/A|
| PV one motor||.33 ± .08||.32 ± .07||.31 ± .07||.31 ± .07||.30 ± .06||N/A|
Reliability Data for CRT, ICC Value 95% CI (Lower Bound, Upper Bound), SEM, and MDC
|CRT||Visual RT||Motor RT|
|WD 1||WD 2||BD||WD 1||WD 2||BD|
| ICC (95% CI)||.90 (0.80 to 0.95)||.79 (0.55 to 0.90)||.90 (0.79 to 0.95)||.63 (0.24 to 0.82)||.49 (0.08 to 0.79)||.70 (0.36 to 0.86)|
| SEM, MDC||0.01, 0.03||0.02, 0.04||0.01, 0.03||0.04, 0.10||0.05, 0.12||0.04, 0.09|
| ICC (95% CI)||.36 (−0.31 to 0.69)||.70 (0.37 to 0.86)||.49 (−0.09 to 0.76)||.66 (0.30 to 0.83)||.17 (−0.76 to 0.61)||.69 (0.34 to 0.85)|
| SEM, MDC||0.10, 0.23||0.05, 0.10||0.09, 0.21||0.04, 0.10||0.06, 0.13||0.04, 0.09|
| ICC (95% CI)||.88 (0.75 to 0.94)||.81 (0.59 to 0.91)||.85 (0.67 to 0.93)||.81 (0.61 to 0.91)||.85 (0.68 to 0.93)||.89 (0.77 to 0.95)|
| SEM, MDC||0.01, 0.03||0.02, 0.05||0.01, 0.03||0.03, 0.07||0.02, 0.05||0.02, 0.05|
| ICC (95% CI)||.59 (0.17 to 0.80)||.84 (0.66 to 0.92)||.67 (0.29 to 0.84)||.69 (0.37 to 0.85)||.55 (0.05 to 0.79)||.74 (0.45 to 0.88)|
| SEM, MDC||0.03, 0.08||0.02, 0.04||0.03, 0.07||0.04, 0.09||0.05, 0.11||0.04, 0.08|