Significant Performance Decrement Research Articles

Performance of Neurologically Impaired Children Copying Geometric Designs with Sticks

The visual-motor performance of 34 brain-damaged children was compared with that of an equal number of children without neurological impairment but matched for IQ, age and sex. Performance involved the copying of geometric designs with sticks rather than drawings. A 14-category rating system was used to evaluate performance. Results indicated statistically significant performance decrement for the brain-damaged Ss, variations in sensitivity among designs and scoring categories for registering performance decrement, and low-to-moderate correlations between test performance and intelligence, age, and mental age. Such results encourage further development of a stick test for young and neurologically impaired children.

Extreme body cooling and psychomotor performance.

Abstract In a series of experiments on the effect of body cooling ( the lowering of Mean Weighted Skin Temperature (MVVST) while maintaining normal Hand Skin Temperature (HST)) on psychomotor performance, the following results were obtained. (I) Block-stringing (BS) and block-packing (BP) performance decreased linearity across levels of body cooling (MWST's of 78° 74° 70° and 66° f). (2) Body cooling (MWST— 70° f) affected steadiness-aiming (SA) performance, but did not affect performance on the Craik screw task, the Purdue pegboard assembly ( PA) task and the two-plate-tapping task. (3) The effect of level of body cooling on SA performance was similar for fast and slow cooling rates. Significant BS and PA performance decrements occurred only under the low level (70° f MWST) and slow rate (90 min exposure) condition. (4) Increasing the duration of exposure for 20 and 40 min after a given MWST condition was attained resulted in significant decreases in BS performance. (5) Practice resulted in improved BS p...

The effects of values and costs on the detection and identification of signals in auditory vigilance.

The effects on performance of the value of detecting a signal, the cost of a miss or false detection, and the size of the set from which the signals were drawn were studied in an auditory vigilance task. Seventy-two subjects were randomly assigned to each cell of a factorial arrangement of the cost and load variables and required to detect and identify each of several 49 db SPL pure tones differing only in frequency. Analyses of the number of correct detections, correct identifications, false detections and detection response time indicated a significant performance decrement with time for all measures and suggested that increasing costs for misses and false detections led to poorer detection performance while value had no effect. Load effected only identification performance, as higher loads led to a decrease in the percentage of signals correctly identified. The ď and β statistics of signal detection theory, indicated sensitivity to be invariant with manipulations of costs and with time. These findings imply that the performance decrement during a vigil is due to an increased strictness in the criterion the subject sets for deciding whether or not a signal was present. The cost factors were effective in manipulating performance by causing changes in the subjects' decision criteria.

The effects of competition and noncompetition on performance of a motor task

Three male adults participated in a study of the effects of competition on a complex motor skill which had been acquired to a high level of proficiency. Each S served as his own control under a noncompetition condition and then competed with each of the other two Ss. A very significant (p< .001) performance decrement occurred; however, certain factors other than competition could be partially responsible.

Effects of chlordiazepoxide on the acquisition of avoidance learning and its transfer to the normal state and other drug conditions.

Rats trained after injection of chlordiazepoxide (CDP), 15 mg/kg, acquired the conditioned avoidance response significantly faster than saline controls. When tested in the undrugged state, CDP trained animals showed virtually no retention of the learned response. Conversely, normally trained rats showed a significant decrement in performance with CDP, whether or not they had received a series of CDP injections following the period of training. CDP trained animals performed much worse than controls on tests with chlorpromazine and amphetamine, despite continued perfect performance on intercurrent CDP tests. Both the rapid learning and the “dissociation” of learning are discussed with reference to the diminution by drug of the spectrum of behavioral responses to novel stimuli, as well as the elimination of the electrical response of hippocampus which normally accompanies these responses to novelty.

The Immediate After-effects of Increased Resistance upon Physical Performance

Abstract It was the purpose of this investigation to evaluate the immediate effects of overload upon vertical jumping performance. Forty-four college men participated in two identical 3-day testing periods during which three levels of overload (no overload, 5 percent and 10 percent of subject's body weight) were applied on a rotational basis. The test sequence involved five pre-overload, three overload, and five post-overload jumps. Paired t tests comparing pre-overload mean scores with post-overload scores indicated non-significant changes for the two experimental conditions but a statistically significant (P<.05) decrement in performance for the control condition. Further analysis of the difference scores (post-overload minus pre-overload) resulted in significant differences (P<.05) between the two experimental conditions and the control. The hypothesis that the application and removal of an overload will lead to an immediate improved performance in vertical jumping is not supported.

Cortical stimulation during learning in rabbits

Rabbits were trained to perform a conditioned avoidance response to a buzzer. Prior to the beginning of training, nonpolarizable electrodes were implanted in the frontal, visual and auditory cortex bilaterally. The effect of cathodal and anodal polarization was tested during the course of training. Cathodal polarization in both the frontal and auditory areas caused a significant decrement in performance, lasting over a period of two days. Cathodal polarization in the visual cortex did not alter the conditioned avoidance response to the buzzer. Anodal polarization produced no consistent effects on performance.

Amount of reinforcement in human learning

Tests were made of the possibility that amount of reinforcement in a simple learning situation has the same effect with human Ss as with subhuman Ss. Common paired associates were learned, with speed of response as the measure of performance, and amount of reinforcement was varied through the exposure time of the correct response item. In Exp. I performance was superior with less reinforcement, but a confounding factor was the varying rhythm of the sounds of the exposure apparatus as response items were presented and removed. When this was held constant in Exp. II the results were similar to those obtained with lower animals, except that a reduction in amount of reinforcement late in training did not lead to a significant decrement in performance.

EFFECT OF INCREASING SIGNAL LOAD ON DETECTION PERFORMANCE IN A VIGILANCE TASK.

Four independent groups of 20 Ss each monitored under four conditions of signal load, 1 light, 4 lights, 16 lights, and 1 light in a 16-light matrix. Significant differences in signal detection performance were found between the single-load conditions and multiple-load conditions, but not between multiple-load conditions. A significant performance decrement, however, was noted in all conditions.

Sensory Deprivation: Its Effects on Human Learning

The rote learning ability of human subjects under conditions of sensory deprivation for 48 hours was compared with results for a control group. The performance of the two groups was essentially the same. No significant facilitation or decrement in performance was noted, and in no instance were hallucinations, delusions, or other unusual phenomena reported.

Effect of Brief Loud Noise on Decision Making

An experiment was designed to investigate whether irrelevant loud bursts of low-frequency noise affected decision-making unfavorably. Analysis of the results revealed a significant decrement in performance due to the noise distraction. Scores for the whole of a 4-min test were unimpaired because only those responses immediately following the noise were affected. A second experiment demonstrated that effects were related to intensity.