Biomedical subjects

J J Turnage

Publications and source records attributed to J J Turnage.

7 recordsLinked to original sources

PubMed1994

Indexing cognitive tests to alcohol dosage and comparison to standardized field sobriety tests.

Cognitive tests from a computerized battery of mental tests and standardized roadside field sobriety tests (FST) were administered in three experiments involving graded dosages of alcohol but different administration schedules. In the first experiment, subjects were raised to one of four levels of alcohol dosage in four sessions 1 week apart. In the second experiment, the descending branch of the blood alcohol concentration (BAC) curve was monitored from 150 mg/dl BAC in a single session. In the third experiment, the ascending and descending limbs of the alcohol dosage curve were followed over a single session. Dose response relationships were observed for all tests, and the changes were statistically significant (p < .001) in all three studies for all tests when evaluated singly, except for grammatical reasoning. When cognitive and FST tests were combined into a single multiple regression analysis, Gaze Nystagmus consistently accounted for the most variance in BAC, followed by code substitution. While multiple regression analyses reveal that tests from the two batteries can be combined to improve overall prediction of alcohol concentration, it is also true that the two batteries share considerable variance (i.e., > 30%). This suggests that, while the two batteries may not be substitutable, they are measuring different aspects of the same thing.

Adult↗

PubMed1993

Effects of graded dosages of alcohol on nine computerized repeated-measures tests.

We report a controlled laboratory validation experiment to provide an empirical sequel to the general background of the development of the Automated Performance Test System (APTS) that was presented in Turnage et al. (1992). The purpose of this study was to index performance deficit against various Blood Alcohol Concentrations (BACs) of small (0.05% BAC), medium (0.10% BAC), and large (0.15% BAC) dosages as well as a placebo (0.00 BAC) condition. Blood alcohol concentrations, measured in four different ways, were highly reliable and the method with the highest intercorrelation was whole blood. When taken singly, eight of the nine tests produced significant (p < 0.001) relationships with the disparate blood alcohol levels, which were essentially monotonic. A multiple regression analysis suggested that most of the tests were behaving similarly and that two or three tests accounted for 52 to 54% of the variance attributable to alcohol that was explained by the longer battery. While all tests appear valid, some of them appeared more sensitive than others (viz., code substitution, manikin, and choice reaction time). From the standpoint of these tests, greater changes occurred in cognitive function between the placebo and 0.05 level than between the 0.05 and 0.10 levels. However, the greatest reduction in performance occurred between 0.10 and 0.15, and the relatively abrupt nature of this change implies that sharp decrements in cognitive performance occur at that point. There were individual differences in resistance to alcohol, and there is strong inference that these differences would be reliable if they were tested again. We believe that further development and study of such techniques is warranted for use in fitness-for-duty testing and development of a dose equivalency index.

Adult↗

PubMed1993

Relating alcohol-induced performance deficits to mental capacity: a suggested methodology.

Performance tests are generally more reliable and more easily administered than on-the-job measures of performance, and in this way are preferable for studying the adverse consequences of environmental stressors. However, a linkage or context would be useful in interpretation of these laboratory measures. This paper reports findings with two indexing methods using multiple regression. In the first study, we illustrate "dose equivalency" where deficits on microcomputer performance tests were related to graded dosages of alcohol, and prediction equations of blood alcohol level were established. In the second experiment, "surrogate criteria" are demonstrated where cognitive mental tests of military aptitude, known to be predictive of operational performances, were administered to a sample who were tested repeatedly on the same microcomputer performance test. Multiple regression analyses of the computerized tests with the amplitude tests were significant (p < 0.01) and ranged from R = 0.50 to 0.94. Finally, the loss in performance owing to alcohol was indexed to loss on the microcomputer tests through the relationship of the tests to the Armed Services Vocational Aptitude Battery (ASVAB). Since the latter is strongly predictive of all forms of military operational performance, we suggest that alcohol-related losses in microcomputer performance test scores can serve as a useful intermediary, permitting meaningful linkage to these real-world performances.

Adult↗

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↗

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↗

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↗

PubMedDate not supplied

The use of dose equivalency as a risk assessment index in behavioral neurotoxicology.

This article reports changes with graduated dosage of alcohol on a standardized set of cognitive and psychomotor performance tests and refers to the approach as dose equivalency. Subjects (N = 20) were tested until their performance was stable on 10 tests from a microcomputer test battery. After administration of sufficient alcohol to achieve .15 blood alcohol level (BAL), using breath as the independent variable, the descending branch of the BAL curve was followed by measuring performance at set levels of alcohol. A dose-response relationship was confirmed in all performance tests (p less than .01), and multiple regression was used to select performance subtests that maximally predicted alcohol level. Four subtests were combined into a linear composite that related well to alcohol levels above 0.05 BAL (shrunken R = .75), which was used in a power function to approximate the roughly linear relation above 0.05, as well as the clearly nonlinear function between 0.05 and zero. It is suggested that alcohol, a powerful central nervous system depressant, can be a useful metric in communicating risk in neurotoxicological research.

Adult↗