Simulated Evaluation of Drug-Impaired Psychomotor Performance

The purpose of this placebo-controlled, randomized-crossover study was to evaluate a computer-based divided-attention task as a method for measure impaired human psychomotor performance. The ability of the divided-attention task to detect and differentiate was evaluated using single oral doses of placebo, caffeine and diphenhydramine. Ten healthy men were the subjects of the study. Subject performance on divided-attention was compared with tests of short-term memory and a set of visual analogue scales. The study also assessed potential learning and boredom effects associated with the testing procedures. The results indicate a divided-attention task can detect and differentiate effects of diphenhydramine from those of caffeine and placebo; however, it cannot differentiate effects of caffeine at the doses utilized from that of placebo. Visual analogue scale results corroborated these findings. Observations show that the short-term memory test was not sensitive to the effects of study medication. While the results observed with this convenient, computer-based divided-attention task are promising, additional studies need to be conducted with other classes of CNS-active drugs and over a range of doses.