Convergence of different versions of the continuous performance test: clinical and scientific implications.

The Continuous Performance Test has been used for the last 40 years to measure sustained attention or vigilance in many different populations. Different versions of the test have been developed, but little is known about how similar these tests are, and to what extent performance on different versions of these tests overlaps. In order to examine convergence of the different versions of the CPT, three different CPTs were administered in both the Auditory and Visual Sensory Modalities. Subjects were selected from consecutive admissions to adolescent acute care units at a private psychiatric hospital (n=100). Auditory test modalities uniformly elicited poorer performance than visual tests, while each set of task demands consistently elicited differences in performance. Despite the high test-retest reliability of the individual subtests, the average correlation between tests was r=.42, with the average correlation between visual tests at r=.48 and the average correlation between the auditory tests was r=.45. The correlations within task demands across sensory modalities ranged from a low of.37 to a high of.52. Controlling for IQ did not influence the correlations to a substantial degree. These data suggest different versions of the CPT are correlated with each other at a level consistent with construct validity, but that they do not constitute alternate forms of the same test.