Samenvatting
Two projects have been carried out to determine the usefulness of employing human operator describing functions in the study of the influence of alcohol and marijuana on subjects performing a visual-manual control task. Significant alterations in the linear operator models were observed and interpreted as changes in the time delay, neuromuscular system, and operator noise injection. The results provide the basis for a linear model capable of describing the dynamic response of human operators while under the influence of the two drugs.