Problem solving by patients with clinically definite multiple sclerosis (MS) was examined using the Wisconsin and California Card Sorting Tests (WCST and CCST). On the WCST, the MS patients achieved fewer categories and made more perseverative responses and errors than controls, confirming results of several previous studies. On the CCST, the MS patients generated and identified fewer concepts, but they performed normally when sorting was cued by the experimenter and they made no more persevcrations than controls. Although findings from the WCST indicate that the problem solving deficits by MS patients closely resemble those exhibited by patients with various conditions that produce frontal lobe dysfunction, results from the CCST indicate that the problem solving difficulties exhibited by patients with MS arc distinct and probably represent a primary deficit in concept formation. (JINS, 1996, 2, 134–140.)

This study tested the hypotheses that older adults make less advantageous decisions than younger adults on the Iowa Gambling Task (IGT). Less advantageous decisions, as measured by the IGT, are characterized by choices that favor larger versus smaller immediate rewards, even though such choices may result in long-term negative consequences. The IGT and measures of neuropsychological function, personality, and psychopathology were administered to 164 healthy adults 18–85 years of age. Older adults performed less advantageously on the IGT compared with younger adults. Additionally, a greater number of older adults' IGT performances was classified as “impaired” when compared with those of younger adults. Less advantageous decisions were associated with obsessive symptoms in older adults and with antisocial symptoms in younger adults. Performance on the IGT was positively associated with auditory working memory and psychomotor function in young adults, and in immediate memory in older adults. (JINS, 2007, 13, 480–489.)