Effect of Practice Schedule on Two-Hand Pursuit Tracking Performance

40 male subjects, ages 18 to 40 yr., practiced tracking a moving target by manipulating a viscous-damped tracking device using two band grips. Eight subjects were assigned to each of five training groups. Four shortened training schedules that were considered as representing massed, distributed, or a combination of massed and distributed trials were compared with a four-day training schedule which had been previously used. Total practice time was the same for all groups. The subjects tracked a target which was moving in a fixed arc at a constant angular velocity of 5 mrad/sec. Horizontal standard deviation ( SD) errors were recorded. Analysis showed significant differences in performance among the groups on a subsequent test day; however, one of the massed/distributed schedules visually showed less variability. Comparison of subjective estimates of “Mental Fatigue” and “Eye Fatigue” among the groups were almost the same. The results are discussed in terms of the schedules most likely to produce stable performance by operators.

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The Tracometer as an Intoxication Warning Device

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/154193128703100713 ◽

1987 ◽

Vol 31 (7) ◽

pp. 751-755 ◽

Cited By ~ 1

Author(s):

Y. Ian Noy

Keyword(s):

Alcohol Intoxication ◽

Blood Alcohol Concentration ◽

Drunk Driving ◽

Alcohol Concentration ◽

Tracking Task ◽

Alcoholic Beverages ◽

Subsequent Test ◽

Pursuit Tracking ◽

Wide Range ◽

Male Subjects

An experiment was conducted to investigate the feasibility of developing an in-vehicle skill-based drunk driver detection and deterrence system. The experiment compared two well-developed psychomotor test devices, the Tracometer and the Critical Tracking Task (CTT), for their ability to detect alcohol intoxication. The Tracometer employed a pursuit tracking task whereas the CTT employed a compensatory tracking task. Twenty male subjects, aged 19 − 30 were trained on the Tracometer and the CTT over a three day period. On two subsequent test days, they were treated with either placebo or alcoholic beverages designed to bring their peak Blood Alcohol Concentration (BAC) to 1.2% (1200 mg/L). On each day, the subjects were tested once before treatment and six times after treatment at hourly intervals as their BAC levels declined. The results indicate that the Tracometer was more sensitive than the CTT to the the effects of alcohol over a wide range of BAC levels. At a BAC level of .08%, performance on the Tracometer deteriorated by 16% whereas performance on the CTT deteriorated by only 7%. Using optimized pass/fail protocols, the Tracometer failed 60% of subjects with BAC in the range .08–1.0%, whereas the CTT failed 34%. At BAC levels above 1.0%, the Tracometer failed about 85% whereas the CTT failed 40%. These results clearly illustrate the potential of the Tracometer as a test of alcohol intoxication. Although the impetus behind the study was the development of drunk-driving countermeasures, the technology can be easily extended to include other applications.

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Effect of Blocked Versus Random Practice on Physical Therapy Students’ Manual Force Modulation

Perceptual and Motor Skills ◽

10.1177/0031512518797845 ◽

2018 ◽

Vol 125 (6) ◽

pp. 1173-1185

Author(s):

Jill Horbacewicz

Keyword(s):

Physical Therapy ◽

Retention Test ◽

Physical Therapy Students ◽

Skill Levels ◽

Practice Schedule ◽

Practice Schedules ◽

Force Magnitude ◽

Practice Organization ◽

Practice Time ◽

Manual Force

This study examined (a) the effect of practice organization on learning to modulate manual force, and (b) the effect of force magnitude on ability to accurately reproduce force. I randomly assigned 52 novice physical therapy students to either blocked or random practice schedules as they learned to apply different manual forces. I tested students immediately after training and one week later, using a three-way mixed design analysis of variance to assess the effects of practice organization (random vs. blocked), test (immediate posttest vs. retention test), and force (high vs. low) on ability to modulate manual forces. I found that blocked versus random practice, led to more accurate force application at the posttest and retention test, F(1, 50) = 5.57, p < .05; both practice groups performed more accurately at the posttest than at the retention test, F(1, 50) = 5.6, p < .05, and both performed more accurately at the lower, compared with the higher, force level, F(1, 50) = 60.9, p < .05. These findings support use of a blocked' practice schedule for this motor training, though relevant contextual interference moderators may include such variables as nature of the task, learners’ skill levels, and practice time. In addition, higher forces resulted in greater errors and must be considered in preparing for and engaging in clinical practice.

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Kinematic analysis of the "attack to the legs" from wrestling: impact of prior judo expertise

Pedagogics psychology medical-biological problems of physical training and sports ◽

10.15561/18189172.2019.0103 ◽

2019 ◽

Vol 23 (1) ◽

pp. 19-23

Author(s):

H. Moufti ◽

A. Arfaoui

Keyword(s):

Prior Experience ◽

Sampling Rate ◽

Three Dimensional ◽

Skill Learning ◽

Motor Skill Learning ◽

Combat Sport ◽

Motor Abilities ◽

Training Schedule ◽

Specificity Of Learning ◽

Male Subjects

Background and Study Aim: In the framework of motor skill learning and transfer, the objective of the present work is to highlight the kinematics during the technical execution of an "attack to the legs" in wrestling and compare expert wrestlers with wrestlers having a prior judo expertise. Moreover, this study aims to evaluate the effects of training on these characteristics. Material and Methods: 10 male subjects were divided in two groups of five: the first group contains wrestlers with at least 7 years of wrestling practice. The second group contains two-year practice wrestlers with 5-year prior judo experience. Subjects had to perform a movement of attack towards the opponent’s legs (free style wrestling). A three-dimensional analysis was carried, the displacement of seven passive markers placed over anatomical points was quantified (3-D motion analyzer, sampling rate 25Hz). The following parameters were calculated: angulation of the hip and of the knee, velocity and acceleration of the shoulder and of the wrist. The experiment was conducted twice: at the beginning of the wrestling training schedule and ten weeks later. Results: Results showed marked differences between the two groups in the kinematics of the movement. These results suggest interference between prior automatisms and learning new skill. The prior experience in judo would have influenced posture in this group. In the framework of skill transfer and dexterity, this study appears promising to investigate the processes involved in this motor control. Conclusions: Although wrestling and judo are two sport disciplines that belong to the same group of combat sport, this work underlines the specificity of learning and indicates that acquisition of motor abilities in a speciality is not transferred inevitably in a positive way in another speciality of the same group

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Manipulating the Number and Type of Adaptive Variables in Training

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/154193127401800511 ◽

1974 ◽

Vol 18 (5) ◽

pp. 534-541

Author(s):

Daniel Gopher ◽

Beverly H. Williges ◽

Robert C. Williges ◽

Diane L. Damos

Keyword(s):

Factorial Design ◽

Rate Control ◽

Tracking Task ◽

Optimum Number ◽

Two Dimensional ◽

Experimental Conditions ◽

Forcing Function ◽

Pursuit Tracking ◽

Transfer And Retention ◽

Stable Performance

To investigate the effectiveness of various types and numbers of adaptive variables, 48 subjects performed a two-dimensional pursuit tracking task for five three-minute training sessions. In the factorial design resulting in eight experimental conditions, three variables (frequency of the forcing function, ratio of acceleration to rate control, and the amount of gain in the control stick) were either fixed or adaptive. A transfer and retention task in which the tracking situation changed periodically was used to evaluate the ability of subjects to adjust to change. Each adaptive variable in training was analyzed separately. With gain more adaption occurred when gain was associated with another adaptive variable. In frequency the highest rate of adaption occurred with frequency alone. In acceleration the rate of adaption was greater early in training when frequency also adapted. During transfer subjects trained adaptively generally showed more stable performance in the changing task situation. No reliable differences among conditions appeared in retention. Results are discussed in terms of stimulus and response similarity, the optimum number of adaptive variables, and the appropriateness of a changing task to evaluate adaptive training.

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Effects of Posture on Back Strength and Lifting Capacity

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/154193128603000308 ◽

1986 ◽

Vol 30 (3) ◽

pp. 234-238

Author(s):

Sean Gallagher ◽

Thomas G. Bobick

Keyword(s):

Body Weight ◽

Pilot Study ◽

Peak Torque ◽

Healthy Male ◽

Strength Tests ◽

Lifting Capacity ◽

Subjective Estimates ◽

Stooped Posture ◽

Male Subjects

The Bureau of Mines performed a pilot study examining the effects of posture on back strength and Maximum Acceptable Weight of Lift (MAWL) on six healthy male subjects (M = 32 years ± 4 SD). Six back strength measurements (3 static and 3 dynamic) were made while the subjects were kneeling and standing. In addition, these subjects (who were unaccustomed to lifting in these postures) volunteered to participate in a study of psychophysically determined MAWL in both postures. Results of the back strength tests showed a significantly lower peak torque per body weight output in kneeling versus standing back strength measurements for five out of six test comparisons (p < .05). Subjective estimates of lifting capacity in the kneeling posture were significantly lower than those for the stooped posture (p < .05). The results of tests of back strength and lifting capacity in these two postures provide useful information to consider in determining the physiological and psychophysical stresses imposed by these work postures.

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Distribution of Practice Combined with Observational Learning Has Time Dependent Effects on Motor Skill Acquisition

Perceptual and Motor Skills ◽

10.1177/0031512520981242 ◽

2020 ◽

pp. 003151252098124

Author(s):

Olave E. Krigolson ◽

Thomas D. Ferguson ◽

Francisco L. Colino ◽

Gordon Binsted

Keyword(s):

Skill Acquisition ◽

Observational Learning ◽

Motor Skill ◽

Distributed Practice ◽

Massed Practice ◽

Practice Schedule ◽

Motor Skill Acquisition ◽

Distributed Training ◽

Training Schedule ◽

Practice Group

Studies of the benefits of a distributed practice schedule on motor skill acquisition have typically found that distribution of practice results in better learning. However, less research has focused on how the benefits of distributed practice are impacted by timing during acquisition. To examine how timing of skill acquisition interacts with distribution of practice we had two groups of participants complete either an extensive massed or distributed training schedule to learn a speed stacking sequence across ten sessions. For participants in both groups, we provided observational learning to facilitate skill acquisition. Analysis of speed stacking time on a retention test revealed an overall benefit for the distributed relative to the massed practice group. Interestingly, our analysis of the benefits of distributed practice during training only showed performance benefits in the early session (session one) and later sessions (sessions eight, nine, and ten) of skill acquisition but not mid-way through it (sessions two through seven). Our results support previous findings highlighting the learning benefits of a distributed practice schedule but suggest that these benefits occur differentially throughout acquisition. Our work also replicates research demonstrating that observational learning is more beneficial when it is yoked to actual practice.

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Ultrastructural Study of Human Testicular Biopsies in Infertility

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090762 ◽

1976 ◽

Vol 34 ◽

pp. 156-157

Author(s):

Shirley Siew ◽

Philip Troen ◽

Howard R. Nankin

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Basement Membrane ◽

Leydig Cells ◽

Clinical Evidence ◽

Young Male ◽

Germinal Epithelium ◽

Transmission Electron ◽

Age Range ◽

Male Subjects

Testicular biopsies were obtained from six young male subjects (age range 24-33) who complained of infertility and who had clinical evidence of oligospermia. This was confirmed on histological examination which showed a broad spectrum from profound hypospermatogenesis to relatively normal appearing germinal epithelium. Thickening of the tubular walls was noted in half of the cases and slight peritubular fibrosis in one. The Leydig cells were reported as normal or unremarkable.Transmission electron microscopy showed that the thickening of the supporting tissue of the germinal epithelium was caused more by an increase in the thickness of the layers of the lamina propria than of the tubular wall itself. The changes in the basement membrane of the tubular wall consisted mostly of a greater degree of infolding into the tubule and some reduplication which gave rise to a multilayered appearance.

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Sound Production Treatment for Acquired Apraxia of Speech: An Examination of Dosage in Relation to Probe Performance

American Journal of Speech-Language Pathology ◽

10.1044/2020_ajslp-19-00110 ◽

2020 ◽

pp. 1-16

Author(s):

Julie L. Wambaugh ◽

Lydia Kallhoff ◽

Christina Nessler

Keyword(s):

Retrospective Analysis ◽

Sound Production ◽

Apraxia Of Speech ◽

Practice Schedule ◽

Practice Schedules ◽

Baseline Performance ◽

The Mean ◽

Number Of Treatment ◽

The Impact

Purpose This study was designed to examine the association of dosage and effects of Sound Production Treatment (SPT) for acquired apraxia of speech. Method Treatment logs and probe data from 20 speakers with apraxia of speech and aphasia were submitted to a retrospective analysis. The number of treatment sessions and teaching episodes was examined relative to (a) change in articulation accuracy above baseline performance, (b) mastery of production, and (c) maintenance. The impact of practice schedule (SPT-Blocked vs. SPT-Random) was also examined. Results The average number of treatment sessions conducted prior to change was 5.4 for SPT-Blocked and 3.9 for SPT-Random. The mean number of teaching episodes preceding change was 334 for SPT-Blocked and 179 for SPT-Random. Mastery occurred within an average of 13.7 sessions (1,252 teaching episodes) and 12.4 sessions (1,082 teaching episodes) for SPT-Blocked and SPT-Random, respectively. Comparisons of dosage metric values across practice schedules did not reveal substantial differences. Significant negative correlations were found between follow-up probe performance and the dosage metrics. Conclusions Only a few treatment sessions were needed to achieve initial positive changes in articulation, with mastery occurring within 12–14 sessions for the majority of participants. Earlier occurrence of change or mastery was associated with better follow-up performance. Supplemental Material https://doi.org/10.23641/asha.12592190

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New AAC Access Strategy for Gesture Tracking: A Technical Note

Perspectives on Augmentative and Alternative Communication ◽

10.1044/aac21.1.11 ◽

2012 ◽

Vol 21 (1) ◽

pp. 11-16 ◽

Cited By ~ 1

Author(s):

Susan Fager ◽

Tom Jakobs ◽

David Beukelman ◽

Tricia Ternus ◽

Haylee Schley

Keyword(s):

Augmentative And Alternative Communication ◽

Technical Note ◽

Head Tracking ◽

Alternative Communication ◽

Access Methods ◽

Cord Injury ◽

Physical Limitations ◽

Gesture Tracking ◽

Communication Needs ◽

Tracking Device

Abstract This article summarizes the design and evaluation of a new augmentative and alternative communication (AAC) interface strategy for people with complex communication needs and severe physical limitations. This strategy combines typing, gesture recognition, and word prediction to input text into AAC software using touchscreen or head movement tracking access methods. Eight individuals with movement limitations due to spinal cord injury, amyotrophic lateral sclerosis, polio, and Guillain Barre syndrome participated in the evaluation of the prototype technology using a head-tracking device. Fourteen typical individuals participated in the evaluation of the prototype using a touchscreen.

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