In: Handbook of Cognitive Aging: Causes, Proceses... ISBN: 978-1-60876-028-2 Editor: Quentin Gariépy and Raphaël Ménard © 2009 Nova Science Publishers, Inc. Chapter 15 Neuropsychological Aspects of Cognitive Aging L.M.K. Forster 1 , R. Kochhann 1 , M.L. Chaves 2 and M. Roriz-Cruz 2 Divisions of 1 Neuropsychology and 2 Neurogeriatrics, Department of Neurology, Brazilian Federal University of Rio Grande do Sul State. Abstract Neuropsychology is an applied science that studies the behavioral expression of brain functions. Behavior can be categorized into three functional systems: (1) cognitive processes, which is the information-handling aspect of behavior; (2) emotion; and (3) executive functions, which are related to those capacities that enable a person to engage successfully in independent, purposive, self-serving behavior. There is a great deal of evidence suggesting that older individuals present with important alterations in their cognitive functionality and that these changes are associated with alterations of brain function with aging. Among such alterations are poorer learning of new information, less efficient working memory and reasoning skills, slower processing speed and higher susceptibility to interfering information. On the other hand, measures of vocabulary and semantic knowledge remain relatively intact until late life. A dominant view in the literature on neuropsychological aging, known as the frontal aging hypothesis, states that age-related changes in the prefrontal cortex are associated with decline in performance on tasks that load on executive functions, such as selecting information to be attended to, task switching or flexibly distributing mental resources. The frontal aging hypothesis is not restricted to the cognitive domain. In fact, besides cognitive impairment and executive dysfunction, apathic-type depressive symptoms, small-stepped frontal gait disorder, and urge incontinence have all been classified under the same pathophysiological process. Recent investigations have, however, indicated that relevant changes with age also occur in other brain areas, such as the temporal and the parietal cortex, and that the frontal functions do not all decline with age at the same rate. Advanced age has also been associated with significantly reduced performance on episodic memory tasks, such as list recall, paired-associate learning, and prose recall. Nonetheless, to date, the attempts to link age-related declines in executive functions and