Many businesses seek to deter impairment due to alcohol and other drugs (AOD's) on the job and feel a need to detect impaired performance due to AOD's directly, rather than by inference from chemical testing. Industry requirements for a performance test to be used in a fitness-for-duty program are that the test have very high specificity and sufficient sensitivity to detect many impaired workers much of the time. To determine if a newly developed computerized temporal acuity test battery had the requisite specificity and sensitivities comparable to those previously obtained with a computerized cognitive performance test battery, performance on the two test batteries was assessed before and after the administration of alcohol. Results indicated that the temporal factors tests did not exhibit sufficient specificity to satisfy industry requirements, however the cognitive tests exhibited high sensitivity and adequate specificity.

Dynamic visual acuity (DVA) thresholds are among the few visual functions found predictive of automobile accidents. DVA is sensitive to alcohol and aging. In two within-subject, repeated-measures designs, a laser DVA device was compared to the traditional device. Both tasks were administered to two groups: Group I received graded stimuli at 60, 75 & 90 degrees per second (dps); Group II at 60, 90 & 120 dps. Testing involved different target sizes, velocities, type of target, and time course changes within a session. Findings: 1) retest reliabilities of the two DVA devices were comparable and higher with the laser; 2) average correlations between the devices were r = 0.62 ( p < .01) and r = 0.65 ( p < .01) for Group I and II respectively. In spite of the known differences in implementation, the laser device can be developed to measure the same construct as the more traditional DVA device, and the laser is considerably more flexible.

To study the potential aftereffects of virtual environments (VE), tests of visually guided behavior and felt limb position (pointing with eyes open and closed) along with self-reports of motion sickness-like discomfort were administered before and after 30 min exposure of 34 subjects. When post- discomfort was compared to a pre-baseline, the participants reported more sickness afterward (p < 0.03). The change in felt limb position resulted in subjects pointing higher (p < 0.038) and slightly to the left, although the latter difference was not statistically significant (p = 0.08). When findings from a second study using a different VE system were compared, they essentially replicated the results of the first study with higher sickness afterward (p < 0.001) and post- pointing errors were also up (p < 0.001) and to the left (p < 0.001). While alternative explanations (e.g. learning, fatigue, boredom, habituation, etc.) of these outcomes cannot be ruled out, the consistency of the post- effects on felt limb position changes in the two VE implies that these recalibrations may linger once interaction with the VE has concluded, rendering users potentially physiologically maladapted for the real world when they return. This suggests there may be safety concerns following VE exposures until pre-exposure functioning has been regained. The results of this study emphasize the need for developing and using objective measures of post-VE exposure aftereffects in order to systematically determine under what conditions these effects may occur.

A study was conducted to determine whether a number of computerized tests would add new variance to a paper-and-pencil selection battery, the U.S. Navy's Aviation Selection Test Battery (ASTB). The computerized tests came from three different domains: 1) cognitive tests; 2) temporal acuity (visual temporal information processing) tests; and 3) psychomotor tests including video games. These tests were all written in “C” and had been validated against simulated aviation and space shuttle landing tasks. Data were collected on 120 aviation candidates. Analyses indicated that: a) Tests in the new automated battery were generally of adequate to high reliability; b) Correlations between the automated battery and ASTB variables were, with a few exceptions, not large but in the expected directions, suggesting that tests in the automated battery do not duplicate the variance measured by the ASTB, and could thus potentially augment the predictive power of the ASTB; and c) Relationships among the Spatial Apperception Test (SAT) of the ATSB and several of the temporal acuity tests indicate that temporal factors may be involved in SAT performance. At the same time, there is considerable reliable variance unique to each domain, again implying the potential for augmentation of the ASTB by measures from the automated battery.

The widespread use of virtual environment VE systems in a variety of applications has serious implications for the user. Users with access to these sophisticated interactive “immersions” in multisensory, three-dimensional 3D synthetic environments have been shown to experience motion sickness-like symptoms i.e., eyestrain, ataxia, fatigue, drowsiness and aftereffects such as visual flashbacks, disorientation, and balance disturbances occasionally occurring up to 12 hours after VE exposure. This is a significant health and safety concern. Technical improvements of VE systems need to be initiated to reduce these potential aftereffects that could result in adverse legal, economic, individual, and social consequences. Many different types of symptoms have been reported that appear to make up the cybersickness syndrome. From our extensive database of virtual environment and flight simulator exposures, we offer examples of these symptoms profiles along with suspected mechanisms and origins. We discuss these issues as well as various assessment techniques and methods used to determine the presence of VE sickness in individuals.

Factor analysis of a large number of motion sickness self-reports from exposure to military flight simulators revealed three separate clusters of symptoms. Based on this analysis a symptom profile emerged for simulators where Oculomotor symptoms predominated, followed by Nausea and least by Disorientation-like symptoms. Current users of virtual environment (VE) systems have also begun to report varying degrees of what they are calling cybersickness, which initially appeared to be similar to simulator sickness. We have found, after examination of eight experiments using different VE systems, that the profile of cybersickness is sufficiently different from simulator sickness — with Disorientation being the predominant symptom and Oculomotor the least. The total severity of cybersickness was also found to be approximately three times greater than that of simulator sickness. Perhaps these different strains of motion sickness may provide insight into the different causes of the two maladies.

“Sensitivity,” (percentage correct detections of the number treated) is the most often used index of psychological tests or test battery adequacy, although other factors (stability, reliability, other forms of validity, usability, etc.) are also reported as positive features. This paper reports on a method to improve “specificity” [ratio of persons correctly identified as not treated to total number not treated]. Specificity issues are a great concern, where behavioral testing may be used for managerial or regulatory decisions about workers. In such cases the percentage of workers with appreciable dosages may be < 10% and false positive percentages thereby become important. In two alcohol experiments, we empirically validated different multiple cut-offs seeking good false positive rates. In two additional alcohol studies we cross validated our optimum findings and found false positive rates of 3.6% (96.4% specificity) can be achieved with a combination of 6% decrement on three of four tests while retaining adequate sensitivity.

This report describes the fourth in a series of studies assessing the impact of graded dosages of alcohol on cognitive performance readiness. This effort differs from our previous studies in several ways. First, the study used a new implementation of six cognitive performance tests that had previously been shown to be sensitive to blood alcohol concentration (BAC). Second, performance was assessed following each of two successive graded doses to a target level of 0.08% BAC. Third, we compared performance on the cognitive tests to the standardized Field Sobriety Test (FST) developed by the National Highway Traffic Safety Administration and to a portable automated posture assessment system (PAPAS) that is video based and that we are currently developing. Results showed that, by using individual baselines, combined performance measures of individual subjects permits detection of alcohol-induced performance changes at rather low BACs. All six tests of the DELTA battery and all three tests of the standard field sobriety test (FST) battery singly predicted alcohol intoxication. When combined with the standard field sobriety test (FST), the DELTA added unique variance to the prediction of alcohol level. The PAPAS test appears to correlate well with the FST and offers the obvious advantage that in addition to being portable, objective, and automatically scored, it also provides a permanent record of the event.