Object, Intensity and Subject Variables in Visual Evoked Response

1976 ◽  
Vol 43 (2) ◽  
pp. 532-534 ◽  
Author(s):  
James C. Norton
Keyword(s):  
Repeated Measures ◽  
Research Strategy ◽  
Intensity Analysis ◽  
Considerable Variability ◽  
Variable Stimulus ◽  
Visual Evoked Response ◽  
Independent Variables ◽  
Object Effect ◽  
Within Subjects ◽  
Subject Variables

10 subjects were studied to determine AEP effects of square, circle, and blank stimuli with variable stimulus intensity For the group as a whole, object and intensity effects were significant on a number of amplitude and latency measures, but the object effect appears largely to reflect the presence or absence of a figure, rather than its nature. Increased intensity differentially affected latency, shortening the first negative deflection while lengthening the second positive. Amplitude is generally increased with higher intensity. Analysis of within-subjects effects showed considerable variability as to which parameters were significantly related to the independent variables in individual subjects. A repeated-measures, within-subjects research strategy is seen as appropriate on the basis of these data.

The Effects of Superficial Heating before 1-MHz Ultrasound on Tissue Temperature

2003 ◽  
Vol 12 (2) ◽  
pp. 95-103 ◽  
Author(s):  
William R. Holcomb ◽  
Chris Blank
Keyword(s):  
Athletic Training ◽  
Repeated Measures ◽  
Outcome Measure ◽  
Tissue Temperature ◽  
Temperature Elevation ◽  
Main Outcome Measure ◽  
Cooling Period ◽  
Dependent Variables ◽  
Within Subjects ◽  
Independent Variable

Context:Ultrasound significantly raises tissue temperature, but the time of temperature elevation is short.Objective:To assess the effectiveness of superficial preheating on temperature elevation and decline when using ultrasound.Design:Within-subjects design to test the independent variable, treatment condition; repeated-measures ANOVAs to analyze the dependent variables, temperature elevation and decline.Setting:Athletic training laboratory.Intervention:Temperature at a depth of 3.75 cm was measured during ultrasound after superficial heating and with ultrasound alone.Subjects:10 healthy men.Main Outcome Measure:Temperature was recorded every 30 s during 15 min of ultrasound and for 15 min afterward.Results:Temperature elevation with ultrasound was significantly greater with preheating (4.0 ± 0.21 °C) than with ultrasound alone (3.0 ± 0.22 °C). Temperature decline was not significantly different between preheating and ultrasound alone.Conclusions:Superficial preheating significantly increases temperature elevation but has no effect on temperature decline during a 15-min cooling period.

scholarly journals Age and Gender Differences in Evaluating the Pedagogical Usability of E-Learning Materials

2019 ◽  
Vol 5 (2) ◽  
pp. 169-189
Author(s):  
Liubomir Djalev ◽  
Stanislav Bogdanov
Keyword(s):  
Gender Differences ◽  
Repeated Measures ◽  
Educational Process ◽  
Instructional Designers ◽  
Learning Materials ◽  
Age And Gender ◽  
Independent Variables ◽  
Age And Gender Differences ◽  
E Learning ◽  
And Gender

The purpose of the study is to examine the pedagogical usability of interactive e-learning materials for foreign language practice. It is based upon two studies of the expected between-group and within-group differences among participants in the educational process. The sample consists of two groups – lecturers and students, a total of 100 participants, each evaluating four materials specifically prepared for this study. Two consecutive repeated measures ANOVA were conducted in which the gender/age, the position of the participants in the educational process, and usability dimensions were the independent variables. Results indicated that all independent variables and their interactions have a significant effects on the evaluations of the pedagogical usability. Women tend to assign higher values than men. Аge groups generally differ in their evaluations, although there is a tendency to give similar ratings for the individual dimensions of pedagogical usability. The 31-40 years age group evaluates the materials higher while the lowest evaluations are given by the groups of 21-30 and 50+ year old participants. Students tend to rate the pedagogical usability systemically higher than the lecturers. Usability dimensions also have a significant effect on evaluations. The most prominent feature of the materials, by a great margin, is their Applicability. The findings corroborate previous research which show age and gender differences in web usability do exist. We conclude that these differences exist as much in pedagogical usability as in technical usability. Further investigations are suggested to explore more deeply the differences in the perceived pedagogical value of e-learning materials as this has implications for instructional designers, teachers and learners alike.

Pairs of Latin Squares to Counterbalance Sequential Effects and Pairing of Conditions and Stimuli

1989 ◽  
Vol 33 (18) ◽  
pp. 1223-1227 ◽  
Author(s):  
James R. Lewis
Keyword(s):  
Human Factors ◽  
Repeated Measures ◽  
Random Sequence ◽  
Latin Square ◽  
Latin Squares ◽  
Sequential Effects ◽  
Long Run ◽  
Within Subjects ◽  
Human Factors Research

This paper discusses methods with which one can simultaneously counterbalance immediate sequential effects and pairing of conditions and stimuli in a within-subjects design using pairs of Latin squares. Within-subjects (repeated measures) experiments are common in human factors research. The designer of such an experiment must develop a scheme to ensure that the conditions and stimuli are not confounded, or randomly order stimuli and conditions. While randomization ensures balance in the long run, it is possible that a specific random sequence may not be acceptable. An alternative to randomization is to use Latin squares. The usual Latin square design ensures that each condition appears an equal number of times in each column of the square. Latin squares have been described which have the effect of counterbalancing immediate sequential effects. The objective of this work was to extend these earlier efforts by developing procedures for designing pairs of Latin squares which ensure complete counterbalancing of immediate sequential effects for both conditions and stimuli, and also ensure that conditions and stimuli are paired in the squares an equal number of times.

Effect of interactive vs. passive virtual reality on pain threshold and tolerance

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Juliann Saquib ◽  
Haneen A. AlMohaimeed ◽  
Sally A. AlOlayan ◽  
Nora A. AlRebdi ◽  
Jana I. AlBulaihi ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Repeated Measures ◽  
Pain Threshold ◽  
Scientific Evidence ◽  
Random Order ◽  
Pain Tolerance ◽  
Dominant Hand ◽  
Interactive Games ◽  
Within Subjects ◽  
Order Sequence

Abstract Objectives Scientific evidence suggests that virtual reality (VR) could potentially help patients tolerate painful medical procedures and conditions. The aim of this study was to evaluate the efficacy of virtual reality on pain tolerance and threshold. Methods A within-subjects experimental study design was conducted on 53 female students at Qassim University in Saudi Arabia. Each participant completed three rounds of assessment: one baseline (no VR) and two VR immersion (passive and interactive) in random order sequence. During each round, participants submerged their non-dominant hand into an ice bath; pain threshold and tolerance were measured as outcomes and analyzed using repeated measures ANOVA. Results Participants had both higher pain threshold and tolerance during interactive and passive VR rounds in comparison to the non-VR baseline assessment (p<0.05). Participants had greater pain tolerance during the interactive VR condition compared to the passive VR condition (p<0.001). Conclusions VR experiences increase pain threshold and tolerance with minimal side effects, and the larger effects were demonstrated using interactive games. Interactive VR gaming should be considered and tested as a treatment for pain.

Pacing and Hazard Score of Elite Open Water Swimmers During a 5-km Indoor Pool Race

2020 ◽  
pp. 1-6 ◽  
Author(s):  
Roberto Baldassarre ◽  
Cristian Ieno ◽  
Marco Bonifazi ◽  
Maria Francesca Piacentini
Keyword(s):  
Swimming Speed ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Open Water ◽  
Rating Of Perceived Exertion ◽  
Mixed Analysis ◽  
Pacing Strategies ◽  
Main Effect ◽  
Within Subjects ◽  
The Relationship

Purpose: The sensation of fatigue experienced at a certain point of the race is an important factor in the regulation of pacing. The rating of perceived exertion (RPE) is considered one of the main mediators utilized by athletes to modify pacing. The aim was to analyze the relationship between pacing and RPE of elite open water swimmers during national indoor pool championships. Methods: A total of 17 elite open water swimmers (males, n = 9; females, n = 8) agreed to provide RPE every 500 m during the finals of the national championships 5-km indoor pool race. Time splits, stroke rate, and RPE were collected every 500 m. The Hazard score was calculated by multiplying the momentary RPE by the remaining fraction of the race. Athletes were placed in one of two categories: medalists or nonmedalists. For all variables, separate mixed analysis of variances (P ≤ .05) with repeated measures were used considering the splits (ie, every 500 m) as within-subjects factor and the groups (ie, medalists and nonmedalists) as between-subjects factor. Results: Average swimming speed showed a significant main effect for split for both males and females (P < .001). A significant interaction was observed between average swimming speed and groups for females (P = .032). RPE increased in both groups (P < .001) with no difference observed between groups. However, the female nonmedalists showed a disproportionate nonlinear increase in RPE (5.20 [2.31]) halfway through the event that corresponded to the point where they started significantly decreasing speed. Conclusions: The results of the present study show different pacing strategies adopted by medalists and nonmedalists despite a similar RPE.

Effect of Septal Perforations on Measures of Nasal Resistance

1997 ◽  
Vol 34 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Thomas W. Guyette ◽  
Bonnie E. Smith
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Dependent Measure ◽  
Nasal Resistance ◽  
Septal Perforation ◽  
Analog Model ◽  
Repeated Measures Anova ◽  
Nominal Scale ◽  
Independent Variables ◽  
Septal Perforations

Objective The purpose of this investigation was to determine the effect of septal perforations on posterior and anterior rhinomanometric measures of nasal resistance In an analog model. Design The data were analyzed using a repeated-measures ANOVA. Nasal resistance was the dependent variable, while type of rhinomanometry, septal perforation size, and position of resistance (proximal vs. distal) were nominal scale independent variables. Participants The analog model used in this study was similar to that described by Warren and Devereux (1966), except that the nasal cavities of the model were modified to create septal perforations. Outcome Measures The main dependent measure was nasal resistance. Results An important finding of this investigation was that septal perforations resulted in large differences (> 3 cm H2O/L/sec) between posterior and anterior nasal resistance values in the bilateral proximal resistor condition. Conclusions Anterior rhinomanometry may underestimate true nasal resistance when a septal perforation Is present, because the septal perforation prevents accurate measurement of nasopharyngeal pressure. Posterior rhinomanometric measures should accurately reflect nasal resistance despite septal perforations, because the perforation does not invalidate the estimate of nasopharyngeal pressure.

scholarly journals Enhancing Accuracy in a Touch Operation Biometric System: A Case on the Android Pattern Lock Scheme

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Allan Ng’ang’a ◽  
Paula M. W. Musuva
Keyword(s):  
Repeated Measures ◽  
Smart Devices ◽  
Biometric System ◽  
Data Set ◽  
Pattern Complexity ◽  
User Training ◽  
Average Accuracy ◽  
Within Subjects ◽  
Dynamic Time ◽  
Future Work

The main objective of this research study is to enhance the functionality of an Android pattern lock application by determining whether the time elements of a touch operation, in particular time on dot (TOD) and time between dot (TBD), can be accurately used as a biometric identifier. The three hypotheses that were tested through this study were the following–H1: there is a correlation between the number of touch stroke features used and the accuracy of the touch operation biometric system; H2: there is a correlation between pattern complexity and accuracy of the touch operation biometric system; H3: there is a correlation between user training and accuracy of the touch operation biometric system. Convenience sampling and a within-subjects design involving repeated measures were incorporated when testing an overall sample size of 12 subjects drawn from a university population who gave a total of 2,096 feature extracted data. Analysis was done using the Dynamic Time Warping (DTW) Algorithm. Through this study, it was shown that the extraction of one-touch stroke biometric feature coupled with user training was able to yield high average accuracy levels of up to 82%. This helps build a case for the introduction of biometrics into smart devices with average processing capabilities as they would be able to handle a biometric system without it compromising on the overall system performance. For future work, it is recommended that more work be done by applying other classification algorithms to the existing data set and comparing their results with those obtained with DTW.

Temporal Changes in Depression Symptoms in Male and Female Collegiate Student-Athletes

2017 ◽  
Vol 11 (4) ◽  
pp. 337-351 ◽  
Author(s):  
Lindsey C. McGuire ◽  
Yvette M. Ingram ◽  
Michael L. Sachs ◽  
Ryan T. Tierney
Keyword(s):  
Repeated Measures ◽  
Student Athletes ◽  
Severe Depression ◽  
Depression Symptoms ◽  
Depression Symptom ◽  
Significant Interaction Effect ◽  
Repeated Measures Design ◽  
Temporal Course ◽  
Clinical Benefits ◽  
Within Subjects

Depression rates in collegiate student-athletes in the literature are varied and inconclusive, and data have only explored depression symptoms utilizing a crosssectional design. The purpose of the current study was to evaluate the temporal course of depression symptoms in student-athletes. Student-athletes (N = 93) from a Division II institution completed six administrations of a brief depression symptom screen once every 2 weeks throughout the fall athletic season. Ten (10.8%) student-athletes’ PHQ-9 surveys were red-flagged for moderate to severe depression symptoms at least once throughout the season. A mixed between-within subjects analysis of variance (ANOVA) revealed a significant interaction effect for time and sex in depression symptom scores, F(3.69, 335.70) = 10.36, p ≤ .001. The repeated-measures design of this study suggests that there are clinical benefits for screening for depression symptoms in student-athletes at multiple intervals throughout an athletic season.

scholarly journals Does the Order of Submaximal Lactate Threshold and Maximal Oxygen Uptake Testing Influence Test Outcomes?

Sports ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 75
Author(s):  
Per-Øyvind Torvik ◽  
Roland van den Tillaar ◽  
Gaute Iversen
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Repeated Measures ◽  
Lactate Threshold ◽  
Test Protocol ◽  
Within Subjects ◽  
Cross Country ◽  
Uptake Test ◽  
Two Stages ◽  
Test Outcomes

The aim of this study was to investigate if the order of submaximal lactate threshold and maximal oxygen uptake testing would influence test outcomes. Twelve well-trained male cross-country skiers (mean age 19.6 years) performed two test sessions within a week in a within-subjects repeated measures with cross-over design study. A maximal oxygen uptake test (VO2max) followed by a lactate threshold (LT) test and vice versa, were performed. The test data included VO2, blood lactate (La-b), heart rate (HR), performance speed, Borg scale (RPE) at all stages and lactate accumulation throughout the whole test protocol including the breaks. No significant effect of testing order was found for: VO2max (74.23 vs. 73.91 mL∙min−1∙kg−1), maximal HR (190.7 vs. 189.9 bpm) and speed at LT during uphill running. Three out of four common definitions of LT resulted in the same La-b at the last two steps, 11 and 12 km/h respectively, in the two protocols. It is worth noting that VO2, HR and La-b were higher in the first two stages of the LT test when VO2max was tested first in the protocol. Well-trained cross-country skiers conclusively attained a similar VO2max and LT in both protocols, and the two tests did not seem to influence each other in terms of the degree of exhaustion that occurs in a single VO2max or an incremental LT test. However, when using a curvilinear function to define the LT, it is important to know that the VO2max test can influence levels of VO2, HR and La-b at the first two stages of the LT test.

Time Estimation: Effects of Cognitive Task, Presentation Rate, and Delay

1996 ◽  
Vol 83 (3_suppl) ◽  
pp. 1387-1394 ◽  
Author(s):  
William F. Vitulli ◽  
Heather A. Shepard
Keyword(s):  
Repeated Measures ◽  
Cognitive Task ◽  
Digit Span ◽  
Presentation Rate ◽  
Time Estimation ◽  
Stimulus Presentation ◽  
Subjective Time ◽  
Allocation Model ◽  
Mixed Analysis ◽  
Within Subjects

The variables of which subjective time is a function extend throughout a myriad of “people, places, and things.” This study measured subjective estimations of time as a function of complexity of cognitive task including arithmetic and recall (within subjects), the rate of stimulus (digit span) information (between subjects), and the delay between stimulus presentation and estimations of time (between subjects). A mixed analysis of variance 2 × 2 × 3 (repeated-measures) factorial design showed that retrospective time estimations were significantly different as a function of the main effects of rate of digit presentation and delay. Men and women showed no differences with no significant interactions so their data were pooled. Quotient values for ratios of delayed versus immediate estimates and slow versus fast rates showed overestimates of “real time.” Explanations based on the “storage-size model,” the “attention-allocation” model, and comparisons with Pedri and Hesketh's 1993 data are discussed.

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