Effects of alcohol and error criticality on alphanumeric target acquisition

Eight male subjects searched for target alphanumeric characters using a touch-input equipped CRT under four levels of blood alcohol concentration (BAC), 0.0, 0.05, 0.07, and 0.09 percent. Participants visually searched randomly generated 108-character arrays for imbedded target characters, touching the CRT surface at target locations when located. Half of the search trials used arrays containing no target, providing the opportunity for "giving up" any search trial at the discretion of the participant. A monetary incentive/penalty system was used to define low- and high-criticality search trials. Search time, touch accuracy, the number of trials completed, percent "give-ups," and hand travel time were all significantly degraded by the alcohol dosages used. An alcohol-by-criticality interaction was observed for percent give-ups, and an alcohol-by-target presence interaction was observed for mean search times. Changes in search time due to alcohol were observed only for trials containing no target.