All subjects were individually administered a comprehensive neuropsychological assessment, beginning with the MicroCog (MC) Assessment of Cognitive Functioning standard version (Powell et al., 1993). The MC is a computerized battery consisting of 18 subtests designed to be sensitive to impairment across a wide range of cognitive functions. It provides age- and education-level adjusted norms. Following a 15 minute break, subjects were administered the following individual tests: Rey-Osterrieth Complex Figure (copy, immediate, and 20 minute delayed) (Osterrieth, 1944), Trail Making Test A and B (Reitan et al., 1985), Controlled Oral Word Association Test (COWAT) (Benton et al., 1983), Symbol Digit Modalities Test (written administration only) (Smith, 1968), Short Category Test (booklet format) (Wetzel et al., 1987), Paced Auditory Serial Addition Test (PASAT) (Gronwall, 1977), Block Design (WAIS-R) (Wechsler, 1981), Stroop Color and Word Test (Golden, 1978) and the American version of the Nelson Adult Reading Test (AMNART), as an estimate of premorbid IQ (Grober et al., 1991). The following 9 domains, and their component tests, were included in the final analyses for neuropsychological performance: (1) Attention (Stroop Color, MC Numbers Forward,
