Abstract
An apparatus for determining a best subject's level of intoxication is described. Included is a display visible to the test subject and in which is produced by test equipment a pair of randomly moving, spaced apart objects. The test subject operates an actuator to indicate his selections of changing imaginary positions in the display having a predetermined constant spatial relationship to the moving objects. Dynamically determined by a computer systems are the actual locations of those positions which are compared with the test subject's selections.