PubMed Health⌕ Search

Biomedical subjects

R S Kennedy

Publications and source records attributed to R S Kennedy.

At least 19 recordsLinked to original sources
PubMed1992

Development of microcomputer-based mental acuity tests.

Recent disasters have focused attention on performance problems due to the use of alcohol and controlled substances in the workplace. Environmental stressors such as thermal extremes, mixed gases, noise, motion, and vibration also have adverse effects on human performance and operator efficiency. However, the lack of a standardized, sensitive, human performance assessment battery has probably delayed the systematic study of the deleterious effects of various toxic chemicals and drugs at home and in the workplace. The collective goal of the research reported here is the development of a menu of tests embedded in a coherent package of hardware and software that may be useful in repeated-measures studies of a broad range of agents that can degrade human performance. A menu of 40 tests from the Automated Performance Test System (APTS) is described, and the series of interlocking studies supporting its development is reviewed. The APTS tests, which run on several versions of laptop portables and desktop personal computers, have been shown to be stable, reliable, and factorially rich, and to have predictive validities with holistic measures of intelligence and simulator performances. In addition, sensitivity studies have been conducted in which performance changes due to stressors, agents, and treatments were demonstrated. We believe that tests like those described here have prospective use as an adjunct to urine testing for the screening for performance loss of individuals who are granted access to workplaces and stations that impact public safety.

Alcoholic Intoxication↗
PubMed1992

Use of a motion sickness history questionnaire for prediction of simulator sickness.

This research assessed the usefulness of the Motion History Questionnaire (MHQ) for the prediction of simulator sickness, a form of motion sickness experienced by pilots training in ground-based flight simulators. Four MHQ scoring keys were compared: (1) the original MHQ key which had been validated on a sample of U.S. Navy student pilots exposed to Coriolis forces, (2 and 3) two keys which had been validated on a sample of civilian college students exposed to simulated ship motions, and (4) a simulator sickness key empirically derived in the present research and cross-validated. Navy and Marine Corps aviators (N = 456) filled out the MHQ prior to their regularly scheduled flight simulator training and were divided into validation and cross-validation samples. All scoring keys were predictive of reported symptoms of sickness, but highest correlations were obtained with the empirically-derived simulator sickness (SS) key. It is suggested that the SS key be used for self-testing so that pilots may be made aware of their risk for developing simulator sickness.

Aerospace Medicine↗
PubMed1991

Communality of videogame performances with tracking tasks.

Performances on three videogames were compared with two different tracking tasks and a third dual tracking task, after stability of performance was achieved by 40 male subjects. The six tasks were performed in succession for three weeks each, and one year separated administration of the tracking tasks from the videogames. Convergence of the cross-correlations among these tasks occurred such that higher correlations were attained for scores obtained late in practice (late/late) of two tasks (even when they were performed a year apart) rather than for scores obtained earlier in training (viz., early/early). High communality between these two types of tasks was observed as indicated by virtual overlap between the videogames and the tracking tasks, even though different control media (joysticks, knobs), control orders (zero/first), and control inputs (displacement/force transducer) were required. Because these tasks apparently index similar abilities, there may be advantages to measuring tracking skills with videogames, which include low cost, wide availability, inherent interest to subjects and motivation, rapid approach to stable levels, and, in many cases greater apparent face validity relative to real world performance requirements.

Adult↗
PubMed1991

A new clinical information system for emergency psychiatry.

A unique and novel Clinical Information System has been set up to link all of the Psychiatric Emergency Rooms in The Bronx, New York. The system is designed from a clinician's perspective and it is an inexpensive system using personal computers. This new system of information exchange utilizes two interesting aspects of applying computer technology to assist clinicians: 1) use of a scannable medical record form to speed the input of data; and, 2) information exchange among many emergency rooms via a dial up access to a central database.

Computer Communication Networks↗
PubMed1990

Eye movement indices of mental workload.

Four investigations were carried out to assess the feasibility of using eye movement measures as indices of mental workload. In the first experiment, saccadic extent was measured during free viewing while subjects performed low, moderate and high complexity, auditory tone counting as the workload tasks. The range of saccadic extent decreased significantly as tone counting complexity (workload) was increased. In the second experiment the range of spontaneous saccades was measured under three levels of counting complexity with a visual task that did not require fixation or tracking. The results indicated that the extent of saccadic eye movements was significantly restricted as counting complexity increased. In the third experiment, the effects of practice were examined and decreased saccadic range under high tone counting complexity was observed even when significant increases in performance occurred with practice. Finally, in experiment 4, the first experiment was repeated with additional optokinetic stimulation and the saccadic range was again observed to decrease with tone counting complexity. The results indicated that the extent of spontaneous and elicited eye movements was significantly restricted as counting complexity increased. We conclude that this measure may provide a valuable index of mental workload.

Adult↗
PubMed1990

Assessment of the Vistech contrast sensitivity test for repeated-measures applications.

Contrast sensitivity using Vistech plates was measured repeatedly in normal subjects to determine predictive power. The contrast sensitivity measures were quite stable from the first administration, and practice effects were not observed. Test-retest reliability was lowest for the lower spatial frequencies, but was adequate throughout if more than one measurement was made. Threshold scores for all five spatial frequencies were generally not independent and factor analysis revealed that only two spatial frequency domains were relatively independent: high and low. The correlations between adjacent spatial frequencies were highest, and correlations decreased as distance between spatial frequencies increased. To detect subtle differences all three Vistech plates should be used to arrive at a threshold for each spatial frequency and, if time permits, more measures should be taken at the lower spatial frequencies to compensate for the lower reliability. This method is believed to be adequate for repeated-measures clinical and experimental studies.

Adult↗
PubMed1990

Differential effects of scopolamine and amphetamine on microcomputer-based performance tests.

Scopolamine (1.0 mg) and d-amphetamine (10 mg) were administered alone and in combination to 16 subjects (medical students), randomly assigned to testing sessions in a fully crossed-over (Latin square) within-subjects design. After being practiced to stability, 9 performance tests from a menu of portable microcomputer-based tests were administered double-blind over 4 weekly treatments (including a placebo). Differential effects of drugs on performance were found. Motor and perceptual speed tests appeared enhanced by d-amphetamine and not degraded by scopolamine. Two of the five cognitive tests showed reductions with scopolamine. The findings are discussed in connection with using a menu of performance tests that can have diagnostic significance for assessment of drug treatments. The effects of scopolamine in this study and others are considered in terms of a model which implies that magnitude of performance deficit depends on performance type (cognitive, motor, self-report) and dosage level. Applying the model, we offer the following summary: below 0.15 mg scopolamine is without any effect; below 0.50 mg, the effect is limited, but can be revealed by some sensitive, complex performance tests and self-report; above 1.0 mg, the effect is likely to impact on operational efficiency.

Administration, Oral↗
PubMed1989

Factor analysis and predictive validity of microcomputer-based tests.

11 tests were selected from two microcomputer-based performance test batteries because previously these tests exhibited rapid stability (less than 10 min, of practice) and high retest reliability efficiencies (r greater than 0.707 for each 3 min. of testing). The battery was administered three times to each of 108 college students (48 men and 60 women) and a factor analysis was performed. Two of the three identified factors appear to be related to information processing ("encoding" and "throughput/decoding"), and the third named an "output/speed" factor. The spatial, memory, and verbal tests loaded on the "encoding" factor and included Grammatical Reasoning, Pattern Comparison, Continuous Recall, and Matrix Rotation. The "throughput/decoding" tests included perceptual/numerical tests like Math Processing, Code Substitution, and Pattern Comparison. The output speed factor was identified by Tapping and Reaction Time tests. The Wonderlic Personnel Test was group administered before the first and after the last administration of the performance tests. The multiple Rs in the total sample between combined Wonderlic as a criterion and less than 5 min. of microcomputer testing on Grammatical Reasoning and Math Processing as predictors ranged between 0.41 and 0.52 on the three test administrations. Based on these results, the authors recommend a core battery which, if time permits, would consist of two tests from each factor. Such a battery is now known to permit stable, reliable, and efficient assessment.

Adult↗
PubMed1989

Motor and cognitive testing of bone marrow transplant patients after chemoradiotherapy.

Assessment of cognitive and motor performance of bone marrow transplant patients prior to, during, and following intensive toxic chemoradiotherapy may provide an important adjunct to measures of physiological and medical status. The present study is an attempt to assess whether, as side-effects, these aggressive treatments result in cognitive performance deficits, and if so, whether such changes recover posttreatment. Measurement of cognitive ability in this situation presents special problems not encountered with one-time tests intended for healthy adults. Such tests must be sensitive to changes within a single individual, which emphasizes the crucial importance of high reliability, stability across repeated-measures, and resistance to confounding factors such as motivation and fatigue. The present research makes use of a microbased portable test battery developed to have reliable and sensitive tests which were adapted to study the special requirements of transplant patients who may suffer cognitive deficits as a result of treatment. The results showed slight but significant changes in neuropsychological capacity when compared to baseline levels and controls, particularly near the beginning of treatment. The sensitivity of the battery in detecting such subtle temporary changes is discussed in terms of past research showing effects of other stressors, such as stimulated high altitude and ingestion of alcohol, on these measures.

Adolescent↗
PubMed1989

Psychology of computer use: IX. A menu of self-administered microcomputer-based neurotoxicology tests.

This study examined the feasibility of repeated self-administration of a newly developed battery of mental acuity tests which may have application in screening for fitness-for-duty or for persons who may be exposed to environmental stress, toxic agents, or disease. 16 subjects self-administered 18 microcomputer-based tests (13 new, 5 "core"), without proctors, over 10 sessions. The hardware performed well throughout the study and the tests appeared to be easily self-administered. Stabilities and reliabilities of the tests from the "core" battery were comparable to those obtained previously under more controlled experimental conditions. Eight of the new tests exceeded minimum criteria for metric and practical requirements and can be recommended as additions to the menu. Although the average retest reliability was high, cross-correlations between tests were low, implying factorial diversity. The menu can be used to form batteries with flexible total testing time which are likely to tap different mental processes and functions.

Diagnosis, Computer-Assisted↗
PubMed1989

The time course of postflight simulator sickness symptoms.

Reports of posteffects following training sessions in Navy and Army flight simulators were obtained from pilots to determine the time course of recovery from simulator sickness. Results imply that posteffects may be a more serious problem than previously considered; 45% of all those queried (N greater than 700) reported having experienced symptoms of simulator sickness; 25% of the symptoms lasted more than 1 h after leaving the simulator; and 8% lasted more than 6 h. Postexposure symptoms were classified into three categories: visuomotor (based on disturbances in oculomotor control; e.g., eyestrain), disorientation (based on disturbance in postural control; e.g., dizziness), and nausea (vagal/autonomic symptoms). A safety risk may be posed particularly by the moderately high frequency of symptoms involving postural disequilibrium. Guidelines for coping with risks are discussed.

Adaptation, Psychological↗
PubMed1989

Simulator sickness in U.S. Navy flight simulators.

Flight simulators have become a major factor in pilot training. A general finding from Navy research on simulator design is that equipment features that offer faithful representation improve pilot performance and promote pilot acceptance. To the extent that an aircraft produces motion sickness, its simulator should induce the same result. However, reports of simulator sickness appear to be increasing and a shortcoming in simulation is implied when these effects occur in simulators during maneuvers that do not occasion them in the aircraft. This article presents incidence data from surveys of the 10 simulators at 6 different Naval/Marine Corps Air Stations. Approximately 1,200 simulator flights were recorded. Some severe motion sickness symptoms were recorded and some simulators induced unsteadiness afterwards. Individuals experiencing effects may be at risk if they drive themselves home or return to demanding activities at work. The simulators which exhibited the highest incidences of sickness were helicopter simulators with cathode ray tube (CRT) infinity optics and six-degrees-of-freedom moving base systems. Of those studied, fixed-wing, fixed-base, dome displays had relatively low incidence of simulator sickness.

Aircraft↗
PubMed1989

Cognitive performance deficits in a simulated climb of Mount Everest: Operation Everest II.

Cognitive function at simulated altitude was investigated in a repeated-measures, within-subject study of performance by seven volunteers in a hypobaric chamber, in which atmospheric pressure was systematically lowered over a period of 40 d to finally reach a pressure equivalent to 8,845 m, the approximate height of Mount Everest. The portable cognitive test battery used, Automated Performance Test System (APTS), was specifically designed for field research under adverse environmental conditions as evidenced by compact computer design; automated test administrations, data storage, and retrieval; psychometric properties of stability and reliability; and factorial richness. Significant impairments of cognitive function were seen for three of the five tests in the battery; on two tests, grammatical reasoning and pattern comparison, every subject showed a substantial decrement. The results are discussed in terms of the impact of altitude on specific aspects of cognitive function and the importance of having sensitive and reliable instruments to monitor such effects.

Adult↗
PubMed1987

Development of an automated performance test system for environmental and behavioral toxicology studies.

In developing a menu of computerized performance tests for repeated-measures applications the metric properties of selected tests have been examined. Factors of chief concern have been stability and reliability, as well as the practical issue of the length of time it takes to achieve high levels of both. In this study, these factors, as well as predictive validity, are examined. 25 subjects were tested repeatedly (10 sessions) with 11 tests previously identified as "good" candidates for repeated-measures research in paper-and-pencil (marker test) versions. The 11 tests were administered concurrently in their traditional paper-and-pencil modes and newly implemented microcomputer-based versions, along with the Wechsler Adult Intelligence Scale (WAIS). Nine of the 11 microcomputer-based tests achieved stability. Reliabilities were generally high, with r greater than or equal to .77 for 3 min. of testing. Cross-correlations of microbased tests with traditional paper-and-pencil versions suggest equivalency between the test constructs in the different media. Correlations between six of the microbased subtests and the WAIS identified common variance, and these might comprise an efficient short (6 min.) battery of tests.

Adolescent↗
PubMed1987

Transfer of perceptual-motor training and the space adaptation syndrome.

Perceptual cue conflict may be the basis for the symptoms which are experienced by space travelers in microgravity conditions. Recovery has been suggested to take place after perceptual modification or reinterpretation. To elucidate this process, 10 subjects who repeatedly experienced a visual/vestibular conflict (Purkinje) over trials and days, were then tested in a similar but not identical perceptual situation (pseudo-Coriolis) to determine whether any savings in perceptual adaptation had occurred as compared to an unpracticed control group (N = 10). The practiced subjects experienced lessening dizziness and ataxia within and over sessions. Their response to the new perceptual situation was markedly less than the control group (p less than 0.001). Assessment of "adaptability," in addition to the provocative vestibular tests now in use, may improve prediction of susceptibility to the space adaptation syndrome. An adaptability trait may exist in humans which, properly measured, could be used to predict who would adapt more readily to visual/vestibular conflict and perhaps to environmental stressors in general.

Adaptation, Physiological↗
PubMed1987

Reliability of provocative tests of motion sickness susceptibility.

Accurate prediction of space motion sickness is dependent, in part, upon the reliability of terrestrial-based motion sickness susceptibility tests. In the present study, test-retest reliability values were derived from motion sickness susceptibility scores obtained from two successive exposures to each of three tests: 1) Coriolis Sickness Sensitivity Index (CSSI); 2) Staircase Velocity Movement Test (SVMT); and 3) Parabolic Flight Static Chair Test (PSCT). The reliability of the three tests ranged from 0.70 to 0.88. Normalizing values from predictors with skewed distributions improved the reliability. The apparent inconsistency between our finding of high reliability of predictive tests, and previous reports of low correlations between ground-based predictors and space motion sickness may be due to unreliability in assessment of the sickness criterion. Issues of reliability and validity of predictor and criterion measures, and their implications for future development of ground-based predictive tests are discussed in some detail.

Acceleration↗