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

Abstract

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.

A review of the literature on the effects of low doses of alcohol on driving-related skills

“…reasoning tests were not generally affected by BACs below 0.080 g/dl, although Heishman et al (1997) and Kennedy et al (1993) reported impairment at BACs of 0.025 g/dl and 0.060 g/dl, respectively. Memory tests, including the Sternberg memory tests, which require subjects to memorize a set of symbols (letters or numbers) and to later determine whether a short sequence of symbols contains the memorized set, were not affected by BACs below 0.060 g/dl.…”

The acute effects of alcohol on memory: A review of laboratory studies in healthy adults

“…Small sets of letters (typically 4-7 letters) are presented briefly, after which participants are presented with a probe letter and asked to indicate whether the probe letter was included in the presentation set. Alcohol has been shown to increase the number of errors and reaction time (RT) on the Sternberg task, although the effect on RT is not consistently observed (7)(8)(9). In one study testing participants during both the ascending and descending limbs of the blood alcohol concentration curve, the number of errors was impaired on both limbs, whereas RT was impaired only on the ascending limb (7).…”

Effects of alcohol and caffeine on maritime navigational skills

“…The ® ndings of various studies suggest that alcohol im pairs cognitive performance such as memory, word¯uency and associations (W allgrew and Barry 1970 ), verbal learning (Rosen and Lee 1976 ), vigilan ce (Horne and Gibbons 1991 ), code substitution, choice reaction time (Kennedy et al 1993 ) free recall and recognition (M aylor et al 1990 ) and so on. M aylor and Rabbitt (1987a ) dem onstrated that the rate of forgetting is signi® cantly increased with alcohol.…”