3D Multiple Object Tracking Boosts Working Memory Span: Implications for Cognitive Training in Military Populations

Recently, there has been much theoretical and applied interest in the prospects of cognitive training for improving cognition. NeuroTracker is a relatively recent training device for improving dynamic attention in athletes by training 3D multiple-object tracking skills. We examined its effectiveness for improving working memory (WM) span in members of the Canadian Armed Forces (CAF) by randomly assigning participants to the experimental (NeuroTracker), active control (adaptive dual n-back task), or passive control (no contact) conditions. NeuroTracker training resulted in significant gains in verbal, visual, and matrix span. No gain was observed in the active or passive control group. These results suggest that NeuroTracker could be a useful training tool for increasing WM span in military samples. Future studies could examine the effects of NeuroTracker training on militarily relevant performance measures that draw on WM span.     

STATISTICAL POWER OF TRAINING EVALUATION DESIGNS

Sample size requirements needed to achieve various levels of statistical power using posttest-only, gain-score, and analysis of covariance designs in evaluating training interventions have been developed. Results are presented which indicate that the power to detect true effects differs according to the type of design, the correlation between the pre- and posttest, and the size of the effect due to the training program. We show that the type of design and correlations between the pre- and posttest complexly determine the power curve. Finally, an estimate of typical sample sizes used in training evaluation design has been determined and reviewed to determine the power of the various designs to detect true effects, given this sample-size specification. Recommendations for type of design are provided based on sample size and projected correlations between pre- and posttest scores.     

Bladder training and enuresis: A controlled trial

This study was designed to test the effectiveness of a short bladder training procedure to increase bladder capacity and to improve enuresis. Eighteen enuretic children, aged 5–13 years, were randomly assigned to either an experimental or control group. Pre- and post-treatment measures of bladder capacity and frequency of bedwetting were obtained from subjects in both groups. The experimental group received 35 days of bladder training administered at first by the experimenter and then by the parents. The training consisted of required drinking, practice in holding and rewards for retaining progressively larger volumes of fluid before voiding. The control group received no training during the duration of the experiment. The results showed that the mean bladder capacity of the experimental subjects increased significantly with bladder training compared to controls. However, the frequency of bedwetting of the experimental subjects did not decrease significantly with training. Consequently, the efficacy of a bladder training procedure in the treatment of enuresis is questioned     

Training respite care providers for families with handicapped children: Experimental analysis and validation of an instructional package

We conducted four experiments to evaluate a respite care training package. In Experiment 1, we assessed the effectiveness of an instructional manual on the acquisition of respite care skills and compared the relative effects of three different manual on the acquisition of respite care skills and compared the relative effects of three different manual presentation formats. Results showed that performance during simulated (role-played) respite care situations improved substantially for all six trainees following presentation of the instructional manual (with no significant differences between presentation formats) although some remedial training was necessary to achieve mastery criterion. In Experiment 2, we evaluated the effects of the manual presented as a whole with a larger group of trainees and compared it to a workshop training approach. Results showed that both the instructional manual and workshop training approaches were effective, but that the former appeared to be more cost-effective. In both experiments, correct responding generalized to a respite care situation with a multiply handicapped child. In addition, several measures of social validity were obtained. In Experiment 3, we evaluated a simplified training and assessment package that could be conducted using the resources typically available to respite care agencies, and in Experiment 4, we demonstrated that respite care agency personnel could successfully implement this program.     

Optimal sample sizes for Welch’s test under various allocation and cost considerations

The issue of the sample size necessary to ensure adequate statistical power has been the focus of considerableattention in scientific research. Conventional presentations of sample size determination do not consider budgetary and participant allocation scheme constraints, although there is some discussion in the literature. The introduction of additional allocation and cost concerns complicates study design, although the resulting procedure permits a practical treatment of sample size planning. This article presents exact techniques for optimizing sample size determinations in the context of Welch (Biometrika, 29, 350–362, 1938) test of the difference between two means under various design and cost considerations. The allocation schemes include cases in which (1) the ratio of group sizes is given and (2) one sample size is specified. The cost implications suggest optimally assigning subjects (1) to attain maximum power performance for a fixed cost and (2) to meet adesignated power level for the least cost. The proposed methods provide useful alternatives to the conventional procedures and can be readily implemented with the developed R and SAS programs that are available as supplemental materials from brm.psychonomic-journals.org/content/supplemental.     

Competition, cooperation, satisfaction, and the performance of complex tasks among air force cadets

Forty-eight U.S. Air Force Academy cadets were studied to examine the effects of individual attitudes and organizational reward structures on the performance of a complex, integrative task. An attitudinal survey was used to measure each subject’s preference for cooperative or competitive situations. Distinctly different group environments were created by giving four groups of six subjectscompetitive instructions and another four groupscooperative instructions. The performance criterion was the “sum” score across eight trials of a complex arcade-type computer game which required one subject to control horizontal movement and another to control vertical movement. Although neither attitude nor reward structure alone influenced performance, their interaction was found to be very significant; subjects performed poorly when the reward structure did not match their individual orientation. Implications for military and professional training programs are discussed.     

Comparison of delayed prompting and fading for teaching preschoolers easily confused letters & numbers

Two teaching strategies, delayed-prompting (Touchette, 1971) and fading (Egeland, 1975), were compared for teaching the most easily confused letters and numbers to preschoolers. One group of children received training using delayed prompting with a fixed delay, a second group with a fading procedure; third served as the control group that received no training. A derived progress score on the training stimuli was calculated by subtracting errors on a pretest from errors on the post-test Analysis of these results indicated a significant difference between the delayed-prompting group and the control group only. The delayed-prompting group showed greater progress. During training, subjects in the fading group met criterion on an average of 4.33 stimuli and the subjects in the delayed-prompting group met criterion on an average of 3.23 stimuli. However, on a criterion test and a posttest given 1 week later, the fading group made significantly more errors than the delayed-prompting group.     

Effectiveness of training in organizations: a meta-analysis of design and evaluation features

The authors used meta-analytic procedures to examine the relationship between specified training design and evaluation features and the effectiveness of training in organizations. Results of the meta-analysis revealed training effectiveness sample-weighted mean ds of 0.60 (k = 15, N = 936) for reaction criteria, 0.63 (k = 234, N = 15,014) for learning criteria, 0.62 (k = 122, N = 15,627) for behavioral criteria, and 0.62 (k = 26, N = 1,748) for results criteria. These results suggest a medium to large effect size for organizational training. In addition, the training method used, the skill or task characteristic trained, and the choice of evaluation criteria were related to the effectiveness of training programs. Limitations of the study along with suggestions for future research are discussed.     

Strategies in the recall of clusterable lists

The present study assessed the effectiveness of a multi-session training aproach intended to teach mildly retarded adolescents to discover and utilize categorical list structure. The performance of a group of trained retarded individuals was compared with that of another group of retarded individuals who had simply received practice with the training materials. The performance of both retarded groups was evaluated relative to that of a group of equivalent-CA normal adolescents. Recall transfer with a new word list was indicated by the finding that trained retarded subjects achieved a criterion of perfect recall in fewer trials than untrained retarded subjects. Differences in the use of categorization strategies by normal and retarded subjects were interpreted in the light of the automatic-controlled processing distinction of Schneider and Shiffrin (1977).     

How to Make Decisions About the Effectiveness of Device-Based Training: Elaborations on What Everybody Knows

Statisticians, biomedical researchers, and behavioral scientists have publicized errors in examinations of the differential effects of 2 or more treatments. Publicity about those errors seems to have been ignored by many applied behavioral researchers, including some responsible for evaluations of device-based training in the U.S. Army. Ignoring the causes and effects of the common evaluation errors, and especially errors associated with hypotheses of equal effectiveness of conventional training and device-based training, leads to logical contradictions, threats to readiness, and a lack of scientifically legitimate ways to examine the effects of OPTEMPO (operating tempo) alterations. Those problems may be avoided by applying a few basics of statistical analysis and inference to the design and interpretation of evaluations of device-based training. The basics include hypothesis tests, power analyses, and confidence intervals; they are elaborated in this article with examples of how to apply each in designing and interpreting evaluations of the Army’s forthcoming Close Combat Tactical Trainer.     

Effects of a stress-management program on injury and stress of competitive gymnasts

20 competitive gymnasts (17 girls, 3 boys; mean age, 14.4 +/- 3.4 yr.) were recruited from two clubs in Auckland, New Zealand. Gymnasts, who had competed at a national or international level, were divided into two groups to examine the effects of a longitudinal stress-management program on injury and stress. Those in the stress-management group took part in 12 1-hr. sessions over 24 weeks, while the control group took part in a placebo program of anthropometric measurements and lectures on nutrition. All participants completed the Life Experiences Survey and Athletic Experiences Survey at baseline, 3 mo., 6 mo. (end of intervention), and 9 mo. (3 mo. after completion of intervention). Injury data were collected prospectively by weekly self-report over the 9-mo. study. Repeated-measures analyses of covariance with age and, where applicable, the baseline measure of the dependent variable entered as covariates, indicated no significant group or group by time effects for the scores on the two surveys, or injury scores. However, given the small sample, the statistical power of the study to detect even large effects was low. Therefore, rather than concluding that the stress-management program had no effect on training hours lost to injury or on stress, upper limits were placed on the magnitude of any effects that might exist. Further research using larger samples is recommended.     

Improving memory performance in the aged through mnemonic training: a meta-analytic study.

The effectiveness of memory training for the elderly was examined through a meta-analysis of pre-to-posttest gains on episodic memory tasks in healthy subjects aged 60 or above. Pre-to-posttest gains were found to be significantly larger in training groups (0.73 SD, k = 49) than in both control (0.38 SD, k = 10) and placebo (0.37 SD, k = 8) groups. Treatment gains in training groups were negatively affected by age of participants and duration of training sessions and positively affected by group treatment, pretraining, and memory-related interventions. No differences in treatment gain were obtained as a function of type of mnemonic taught nor the kind of pretraining used.     

Child sexual abuse prevention programs: a meta-analysis

Conducted a meta-analytic evaluation of the effectiveness of school-based child abuse prevention programs. Literature searches identified 27 studies meeting inclusion criteria for use in this meta-analysis. The average effect size for all programs studied was 1.07, indicating that children who participated in prevention programs performed 1.07 SD higher than control group children on the outcome measures used in the studies. Analysis of moderator variables revealed significant effects for age, number of sessions, participant involvement, type of outcome measure, and use of behavioral skills training. Most important, programs presented over 4 or more sessions that allowed children to become physically involved produced the highest effect sizes. Although most often used only with younger children, findings suggest that active, long-term programs may be more effective for children of all ages.     

Rule learning in children: Multiple-set training and intermediate-size transposition

Two experiments were conducted in which the subjects were trained to choose the middle-size stimulus in either a single stimulus set or in each of two nonoverlapping stimulus sets. Following criterion, each subject was presented with a series of 12 test trials involving a new stimulus set. In Experiment 1, kindergarten children tended to choose the middle-size test stimulus if the test set consisted of stimuli intermediate in size to the stimuli in the smaller and larger training sets. When the test stimuli were all larger than any of the training stimuli, the probability of choosing the middle-size stimulus increased as the distance between the two training sets increased. Three groups of children participated in Experiment 2: a kindergarten group, a first-grade group, and a first-grade group that experienced middle-size training a year earlier. The distance between training sets and two training procedures affected the three groups in a similar manner during acquisition, but several interactions were obtained during the test. The findings were discussed in terms of the Lane and Rabinowitz (D. M. Lane & F. M. Rabinowitz, Child Development, 1977, 48, 412–426) rule based theory of intermediate-size transposition and suggestions were made as to how children acquire the concept of middle.     

The costs of selecting power bases or messages associated with the opposite sex

A study was conducted to examine the interpersonal costs of using power bases associated with the opposite sex. The study also tested two hypotheses regarding influence differences associated with two statistical interactions: (1) the sex of the source by the sex-type of the message, and (2) the sex of the subject by the sex-type of the message. Subjects (N=387) viewed a videotype containing one of six speakers (three males, three females) delivering one of two speeches (about gun control or child care centers) and using one of two power bases (helplessness or expertise). The results indicated that speakers using power bases associated with the opposite sex were liked less and regarded as less competent and qualified than their counterparts. The results also indicated that female speakers aroused more belief in the child care message and male speakers aroused more belief in the gun control message than did the other speaker-message combinations. No significant effects were associated with the interaction between subjects' sex and message. Among other findings, female subjects generally rated the messages and the speakers more positively than did male subjects.     

A standard for test reliability in group research

Many authors adhere to the rule that test reliabilities should be at least .70 or .80 in group research. This article introduces a new standard according to which reliabilities can be evaluated. This standard is based on the costs or time of the experiment and of administering the test. For example, if test administration costs are 7 % of the total experimental costs, the efficient value of the reliability is .93. If the actual reliability of a test is equal to this efficient reliability, the test size maximizes the statistical power of the experiment, given the costs. As a standard in experimental research, it is proposed that the reliability of the dependent variable be close to the efficient reliability. Adhering to this standard will enhance the statistical power and reduce the costs of experiments.     

The influence of stimulus-set size on developmental changes in cognitive control and conflict adaptation

Cognitive control abilities substantially improve from early childhood to adulthood. The primary aim of this study was to examine the influence of stimulus-set size on developmental changes in cognitive control abilities such as task switching, interference control, and conflict adaptation. We assumed that a small stimulus set used in a task-switching paradigm would induce stronger task-stimulus priming that might increase the need for control, thereby amplifying age differences in cognitive control abilities. Therefore, we compared task-switching performance in a group of participants responding to a small stimulus-set (N=4) with a group responding to a large stimulus-set (N=96) in three age groups: kindergarten children (4.1-6.0 years of age), elementary school children (6.1-9.0 years of age), and young adults (21.0-28.0 years of age) on conflicting vs. non-conflicting trials (interference control) and following conflicting vs. non-conflicting trials (conflict adaptation). Results on the basis of error rates support the view that a small stimulus-set size during task switching (i.e., larger task-stimulus priming) increases the need for control as we found (a) worse conflict adaptation on task-repetition trials only for small but not for large set sizes and (b) larger interference costs under small than large set-size condition for elementary school children as compared with young adults. Kindergarten children were less sensitive to the set-size manipulation and showed major problems in interference control while being in a task-switching situation, even if no actual task switch was required, possibly reflecting their inability to represent complex higher-order task rules.     

ACQUISITION,DISCRIMINATIVE STIMULUS CONTROL,AND RETENTION OF INCREASES/DECREASES IN BLOOD PRESSURE OF NORMOTENSIVE HUMAN SUBJECTS1

The aims of this study of 24 normotensive subjects were: to compare a free-operant with a discrete-trials training format; to determine the most effective training procedure by comparing instrumental conditioning with instructional set and a control; to see if both increases and decreases in blood pressure could be brought under discriminative control, and to examine the maintenance of acquired self-control of blood pressure. A 2 × 3 design was employed in which two trial formats (free operant and discrete trials) were factorially compared with three training conditions (instrumental conditioning, instructional set, and control). Instrumental conditioning was found superior to both the instructional set and control conditions in producing increases and decreases in mean diastolic blood pressure. The free-operant format led to a greater degree of learned BP control in that subjects were able to increase and decrease their blood pressure by 10% to 15% of basal value and to maintain the blood-pressure operant after contingent auditory feedback/reinforcement was removed. Training was discontinued when subjects in the other five groups failed to reach criterion after 10 consecutive acquisition sessions.     

The Impact of Covariates on Statistical Power in Cluster Randomized Designs: Which Level Matters More?

Field experiments with nested structures are becoming increasingly common, especially designs that assign randomly entire clusters such as schools to a treatment and a control group. In such large-scale cluster randomized studies the challenge is to obtain sufficient power of the test of the treatment effect. The objective is to maximize power without adding many clusters that make the study much more expensive. In this article I discuss how power estimates of tests of treatment effects in balanced cluster randomized designs are affected by covariates at different levels. I use third-grade data from Project STAR, a field experiment about class size, to demonstrate how covariates that explain a considerable proportion of variance in outcomes increase power significantly. When lower level covariates are group-mean centered and clustering effects are larger, top-level covariates increase power more than lower level covariates. In contrast, when clustering effects are smaller and lower level covariates are grand-mean centered or uncentered, lower level covariates increase power more than top-level covariates.