Self-paced Task Research Articles

Effectiveness of a Global Learning Strategy Practiced in Different Contexts on Primary and Transfer Self-Paced Motor Tasks

(Singer, 1986) on achievement in laboratory and simulated self-paced sport tasks were investigated. Forty undergraduates were randomly stratified according to gender into four treatment groups: (a) a strategy group that initially practiced the strategy while learning the laboratory task (SL), (b) a laboratory control group that began the experiment by learning the task without the strategy (CL), (c) a strategy group that initially applied the strategy to the learning of an applied sport task (SA), and (d) a control group that initially learned the sport task without the strategy (CA). Following the completion of 48 trials with the primary task, all groups performed 50 trials on a transfer task. ANOVAs indicated that both strategy groups performed significantly better than their respective control groups in the primary tasks. Results of the transfer task indicated that the SA group performed at the same level as the SL group but outperformed both control groups. It was concluded that the strategy facilitates achievement in laboratory as well as applied self-paced tasks.

The effect of a five-step cognitive learning strategy on the acquisition of a complex motor task

Abstract Investigated was the effectiveness of the Five-Step Learning Strategy in facilitating the learning of a complex self-paced motor task. Thirty undergraduate students were randomly assigned to one of three conditions, after being stratified as to number and sex: (1) a strategy group, that was administered the Strategy, (2) a preview group, that previewed the location of the targets, and (3) a control group. All subjects performed 48 trials in an attempt to learn a task that required speed and accuracy in mastering a sequence of responses. ANOVA analyses indicated that the Strategy group performed significantly faster than the other two groups, and not at the expense of a greater number of errors. These findings indicate that cognitive processes involved in learning a complex skill are likely to benefit from the utilization of the Five-Step Strategy.

Isometric Strength Tests: Predicting Performance in Physically Demanding Transport Tasks

A study explored the applicability of a battery of four isometric strength tests to steward, utility and warehouse jobs in a company that services offshore drilling and production facilities in the petroleum industry. The jobs involve frequently transporting materials up stairs, a category of tasks not prominent in situations where these tests have previously been applied. A job analysis established critical task requirements such as procedures, weights, distances, sizes of containers, etc. An experiment was then carried out with 25 male and 25 female subjects. The subjects performed two self-paced job-related tasks: transporting a 15.9 kg box up and down stairs and similarly transporting a 22.7 kg box. Measures included heart rate and amount of work performed, which, along with known task parameters, was used to calculate work power. Subjects also performed four standard isometric strength tests: grip, arm lift, back lift and arm press. Correlations between job task and strength performance indicated these tests are applicable to jobs with such requirements, thus extending the generalizability of the strength test battery.

Pronoun resolution in two-clause sentences: Effects of ambiguity, antecedent location, and depth of embedding

The two experiments reported here were designed to study anaphoric pronoun resolution by measuring the effects of syntactic ambiguity, antecedent location, and depth of antecedent embedding on sentence-final reading comprehension time. Fifty-two college students read sentences in a word-by-word self-paced task and answered a question after each. Syntactic cues indicated the appropriate antecedent in the unambiguous sentences, while in the ambiguous sentences, the semantic context of the second clause cued the antecedent. Results of Experiment 1 showed that comprehension time was significantly faster for the unambiguous sentences. In both experiments, comprehension time in ambiguous sentences was faster when the antecedent was located early in the first clause than when it was located late in the clause. In Experiment 2, the interaction of embedding by location showed slower comprehension times for sentences with early deep antecedents than for sentences with late shallow antecedents. These results are consistent with predictions derived from Hobbs' (1978, Lingua, 44, 311–338) algorithm for a top-down left-to-right breadth-first search.

On the construction of representations for individuals from descriptions in text

Abstract Subjects read texts describing pairs of individuals sentence by sentence in a self-paced reading time task and then answered questions about the individuals and recalled them. The task is designed to explore how people represent the binding of attributes to individuals. The reading time data show that the construction of representations is organised around what is known about the currently referenced individual. The more that is known the more slowly subjects read. This slowing is not due to articulatory rehearsal. A regression model of reading times describes the partitioning of working memory resources across the semantic structures being processed. The construction processes yield redundant representations consisting of sets of feature values encoding aspects of the information in the text and contributing independently to memory performance. Modelling in terms of feature representations enables prediction of the patterns of error in recall. The reading time and recall error models are interpr...

Eye Color and Motor Performance in Physical Education Activities in Elementary School Children

251 elementary school children in Grades 1 to 6 performed a variety of motor tasks in physical education classes to investigate whether eye color was associated with performance on the expectation that dark-eyed individuals generally perform better at reactive type tasks (boxing, hitting a baseball, defensive football) while light-eyed individuals perform better at self-paced tasks (bowling, golf, pitching baseballs). Eye color was not associated with standing-long jump, soft-ball throw, or 50-, 75-, 100-yd. dashes. Boys generally performed better than girls and older children in upper grades generally performed better than younger children in lower grades. As measured, all motor performances cannot be classified as either self-paced or reactive.

Occipital midline EEG and subjective rating of task difficulty as indices of mental task strain.

Three measures of mental task strain, namely performance level, occipital midline beta-2 (Oz beta 2) amplitude and subjective rating of task difficulty, were taken in 34 healthy male students aged 19-24 years as they performed either a paced or a self-paced calculating task for 4 h. The performance levels were so constant throughout the work periods that they were of no use in evaluating mental task strain. The Oz beta 2 amplitudes increased significantly with the execution of both tasks, and a significant increase took place during the self-paced task work periods. From this, a critical value of Oz beta 2 amplitude for a heavy task strain was estimated to be about 3.5 microV (the difference between the values at work and at rest). The subjective ratings of task difficulty rose linearly with work time in both tasks. The subjective task strain attributable to work time was found to exceed the critical level long before the objective measure. In addition, other results suggest that the Oz beta 2 activity attributable to task execution is related to the capacity for achieving the task.

An Optimization Model of Self-Paced Tracking

A model which describes human performance in a self-paced tracking task was developed based on the notion that human operators are intermittent-acting or sampled-data servo-mechanisms. The model had a functional form in terms of the probability of success and failure resulting from the execution of a manual control task such as drawing a line between fixed boundaries. The human operator was modelled as an optimizer, balancing costs and penalties of speeds and errors to achieve a maximum expected payoff. The performance of the model was evaluated by simulating a line drawing task on a digital computer. Model predictions obtained via simulation were compared with the data collected from human subjects performing the actual task in a laboratory setting. The predictions of the model were confirmed, suggesting that human operators can in fact be modelled as optimizers when performing a manual control task.

Information-Theoretic Analysis of Randomization and Spontaneous Activity

The purpose of the study was to determine the information-theoretic measure of redundancy for a sequence randomized by subjects and for a sequence spontaneously produced by subjects. It was hypothesized on the basis of previous findings with self-paced tasks that redundancy in the sequence under conditions of spontaneous activity would be higher than under conditions of randomization. 28 subjects were instructed to randomize three alternative push-button responses or to produce a spontaneous sequence of such responses. Both tasks were paced by a metronome and performed twice. As expected, redundancy was significantly higher in the condition of spontaneous activity. Redundancy was also higher in the second task and seemed to be higher in paced tasks as compared with previously published data obtained with the use of self-paced tasks. The latter effect was interpreted as a function of a superimposed activity of synchronization of responses with a time marker. Higher redundancy of spontaneously produced sequences was said to be firmly established and independent of pacing or nonpacing of responses.

INFORMATION-THEORETIC ANALYSIS OF RANDOMIZATION AND SPONTANEOUS ACTIVITY

The purpose of the study was to determine the information-theoretic measure of redundancy for a sequence randomized by subjects and for a sequence spontaneously produced by subjects. It was hypothesized on the basis of previous findings with self-paced tasks that redundancy in the sequence under conditions of spontaneous activity would be higher than under conditions of randomization. 28 subjects were instructed to randomize three alternative push-button responses or to produce a spontaneous sequence of such responses. Both tasks were paced by a metronome and performed twice. As expected, redundancy was significantly higher in the condition of spontaneous activity. Redundancy was also higher in the second task and seemed to be higher in paced tasks as compared with previously published data obtained with the use of self-paced tasks. The latter effect was interpreted as a function of a superimposed activity of synchronization of responses with a time marker. Higher redundancy of spontaneously produced sequences was said to be firmly established and independent of pacing or nonpacing of responses.

Sleep, Biorhythms and Human Performance

Sleep, Biorhythms and Human Performance

Representation-saving effects of prior knowledge in memory for simple technical prose.

Prior knowledge of the content of a passage should reduce the effort required to encode the passage and facilitate its recall. This paper presents such effects of prior knowledge upon comprehension and memory of simple technical prose. The basic procedure was to collect ratings of the amount of prior knowledge for individual passage sentences and individual subjects, and then to determine whether these familiarity ratings predicted study time and recall. In order to validate the rating method, and also to obtain data on prior knowledge of individual facts, subjects also completed an objective test of prior knowledge of the passage facts. Three different encoding-task conditions were used: a self-paced study task, a forced-pace study task, and an incidental-learning task. A cued-recall test followed each condition. In the self-paced task, readers studied unfamiliar material longer than familiar material, but recalled at the same level regardless of familiarity. In contrast, familiarity did predict recall in the forced-pace and incidental tasks. This task specificity is explained in terms of the subjects’ encoding strategies. The basic effect of prior knowledge can be explained not only by the elaboration principle, but also by a representation-saving principle, which is presented in a simulation model that can account for the effects of familiarity on study time.

Type A components and psychophysiological responses to an attention-demanding performance task.

Although Type A and B individuals appear to differ in psychophysiological responsivity, situations eliciting these differences have not been specified. The current experiment parametrically manipulated response speed in order to examine differences between behavior types in psychophysiological responsivity to this variable. Cardiovascular responses and performance in this paced task were compared to those from a task performed without explicit speed pacing in 24 businessmen classified as Type A or not. Only Type A businessmen showed a well-developed heart rate response in the self-paced task. In the experimenter paced task, the heart rate response of Type A's was most consistent when paced at fast response times; that of non-A's was most consistent when paced at relatively slow response times. Businessmen high in the Speed/Impatience component of Type A initiated anticipatory heart rate slowing later than non-A's and recovered less promptly. Overall relative to non-A's, A's appear to become readily involved and physiologically responsive to a task. Once involved, their responding is altered most by requirements for anticipation and relatively slow controlled response.

Wholistic and Analytic Stimulus Processing: The Development of Selective Perceptual Strategies

This experiment reports an investigation of the development of selective processing strategies as subjects become increasingly more practised at a serial self-paced RT task. It demonstrates the effect a preceding stimulus can have on the analysis of a current signal and the development of active analytic strategies in favour of passive wholistic processing, with practice. The stimuli used were letters with irrelevant visual noise dot patterns superimposed on them. The letter, or the dot pattern, or both, could be repeated on successive trials. Early in practice repetition of both stimulus components simultaneously produced short reponse latencies relative to repetition of the letter alone. The number of noise dots markedly affected RT. Late in practice, however, letter repetition RTs were small, irrespective of whether or not the noise dot pattern was repeated. Furthermore, the number of noise dots no longer had an effect on the RT to these stimulus transitions. The results suggest that subjects appear to be able to select relevant information to process as they become progressively more practised, even though there is evidence that they compare the current stimulus with an iconic representation of the immediately preceding one.

Tracking Capacity Measured by Informational Statistics

Information-theory statistics were used as performance measures during selfpaced pursuit tracking tasks with a time-discrete band-limited white Gaussian noise reference input and both time-discrete and time-continuous response signals. The experimental results from 64 subjects showed that the generated information rate increased exponentially with increasing input variance or input entropy. The spacing between successive input points had no general significant effects on the information rate. Discrete responses produced significantly higher information rates than continuous responses. The maximum information capacity was determined to be centered at about 10 bits/sec with asymptotes at about 11 bits/sec for discrete responses and 9 bits/sec for continuous responses.

Developmental Changes in the Effects of Instructions on Production-deficient Children

BRAY, NORMAN W.; JUSTICE, ELAINE M.; FERGUSON, ROBERT P.; and SIMON, DEBORAH L. Developmental Changes in the Effects of Instructions on Production-deficient Children. Cmum DEVELOPMENT, 1977, 48, 1019-1026. Firstand third-grade children were tested under 6 different instruction conditions which varied in how explicitly they cued a rehearsal strategy in a self-paced sequential-memory task. The type of strategy adopted was monitored with study time and overt verbalization measures. Instructions to either look, remember, label, or say the picture names over and over did not prime the use of cumulative rehearsal. Modeling of cumulative rehearsal was necessary for the younger children, whereas cumulative-rehearsal instructions were sufficient for the older children. Since both age groups were production deficient on this task, the results illustrate that production deficiencies are not all-or-none phenomena and that they are dependent on particular task conditions.

Energy expenditure and physiological performance of Sudanese cane cutters.

The thermal and exercise tolerances of 165 Sudanese cane cutters were measured in the laboratory and related to work performance and productivity in the cane fields. The results showed that the amount of cane cut per minute in the field was significantly correlated with changes in body weight (r = +0-53) during the third hour of work, aerobic energy expenditure (r = + 0-43), and cardiac frequency during work. These variables in turn were associated with predicted maximal power output (VO2 max) measured in the laboratory. The average energy expenditure during cane cutting was 1-66 +/- 0-33 1/min-1 (34-9 kJ/min-1) which represents approximately 60% of the workers predicted VO2 max. This rate of energy expenditure was sustained in the cane fields for at least three hours without significant pauses for rest. The sweat losses measured in 32 cane cutters during the two and three hours of work averaged 637 +/- 221 and 770 +/- 282 g/h-1 respectively, while the mean urine temperature immediately on cessation of effort was 37-74 +/- 0-46 degrees C. Despite the additional environmental heat load of the tropics, it would seem that cane cutters performing a self-paced task demanding heavy physical effort, are able to sustain work levels well in excess of those recommended for most European factory workers without obvious signs of fatigue or heat stress.

Verbal, Visual, and Kinesthetic Error Feedback in the Learning of a Simple Motor Task

Abstract Sixty subjects (30 males and 30 females) attempted to learn a self-paced positioning task using verbal, visual, or kinesthetic error feedback. The three methods of presenting error information were found to be equally effective in learning the task. Contrary to previous findings, the results of the present study support the use of kinesthetic error feedback in early stages of learning. The observed viability of kinesthetic error feedback compared with verbal and visual error feedback is enlightening in view of subject's orientation toward the use of more familiar verbal or visual cues rather than novel kinesthetic cues. No significant sex effects were found to exist in the present study.

Effect of speed adaptation on performance in a self-paced tracking task.

12 Ss were required to perform a self-paced tracking task designed to simulate 'hazardous' road conditions. Those 6 Ss who had previously been exposed to a simple, high-speed version of the task travelled faster and made more errors on the hazardous task than 6 control Ss who performed the hazardous task throughout the experiment. The findings supplement earlier studies of the effect of speed adaptation on the judgment of speed and suggest that, in addition to perceptual distortions, an acquired motivation for speed may be an important factor in the behaviour of drivers leaving high-speed roads.

Some effects of ACTH 4-10 on performance during a serial reaction task

Eighteen subjects worked continuously for half an hour in a self-paced reaction task. Half of the subjects were injected with ACTH 4-10 (30 mg/s.c.) and the other half with a placebo. The subjects injected with ACTH 4-10 showed a larger improvement in reaction time during the experimental session than the placebo group. However, this effect disappeared in a short retest, which was given half an hour after the experimental session. These results suggest that ACTH 4-10 has no effect on skill acquisition, but counteracts the build-up of reactive inhibition during the experimental session; that is, the peptide suppresses the decrease in motivation, which usually occurs during continuous performance tasks. This notion is confirmed by an analysis of the frequency distributions of the reaction times. Treatment effects were only found for the long reaction times. Long reaction times tend to occur with increasing frequency as a function of time-on-task and are an indication for the level of motivation of the subject. It was concluded that ACTH 4-10 counteracts the usual decay in performance as a function of time-on-task due to increasing boredom and mental fatigue.