“…In the two studies in which differences were not found-the Boston (Cohler, Grunebaum, Weiss, Garner, & Gallant, 1977;Herman, Mirsky, Ricks, & Gallant, 1977) and the Danish Birth Cohort (Orvaschel et al, 1979) studies--the relative simplicity of the tasks may account for the negative findings (ErlenmeyerKimling et al, 1982;Nuechterlein, 1983). Versions of the Continuous Performance Test (CPT), a test of sustained visual attention, that produce very few errors in performance do not differentiate well between children of schizophrenics and children of normal parents Cohler et al, 1977;Erlenmeyer-Kimling et al, 1982;Erlenmeyer-Kimling, Kestenbaum, et aI., 1984;Grunebaum, Cohler, Kauffman, & Gallant, 1978;Nuechterlein, 1983), whereas more complex versions appear to work very well in this regard Erlenmeyer-Kimling, Cornblatt,& Golden, 1983;Nuechterlein, 1983;Rutschmann, Cornblatt, & Erlenmeyer-Kimling, 1977). Task parameters, rather than the type of process or sensory modality that the tests tap, appear to determine whether a particular test will successfully distinguish high-risk subjects.…”