The digit vigilance test: reliability, validity, and sensitivity to diazepam

The Digit Vigilance Test (DVT), a measure of sustained attention and psychomotor speed, was evaluated in terms of test-retest and alternate-form reliability as well as sensitivity to a single dose of diazepam (10 mg). A one-page version was compared to the standard two-page format. Forty undergraduates, randomly assigned in a double-blind manner to either drug or placebo condition, were tested three times in two sessions (1 week apart). Both Page 1 and Total Time scores were found to be highly reliable across time and forms. Repeated measures ANOVAs revealed the Total Time score, but not the Page 1 score, to be significant in discriminating diazepam from placebo across time, supporting the use of the complete DVT for measuring drug effects. Findings based on convergent measures also help to validate the DVT as a measure of sustained attention.