Effects of lateralized cerebral dysfunction on the Continuous Paired-Associate Test.

Some authorities have advocated matching tests on several critical psychometric properties before inferring the presence of a differential pattern of deficit. This study examined the effects of lateralized cerebral dysfunction on the matched Verbal and Design subtests of the Continuous Paired-Associate Test (CPAT). Patients with lateralized destructive lesions were studied in Experiment 1. Epileptic patients with lateralized electroencephalographic findings were studied in Experiment 2. Left but not right hemispheric abnormalities impaired performance on the Verbal CPAT, but only for destructive lesions. The Designs CPAT was a nonspecific indicator of cerebral dysfunction. For studies with the goal of predicting laterality of cerebral dysfunction, we advocate a two-step strategy of test development. The first step would make use of the principle of double dissociation in selecting items to compose subtests. The second step would involve an item analysis of subtests to determine the need for matching.