We worked from a conceptual framework that describes the aging mind in terms of three interacting systems that support the performance of cognitive tasks: cognitive structures and processes, neural health, and behavioral context, including task structure and social, cultural, and technological factors. We use the term ''the aging mind" to signal a broad conception of cognitive aging that includes not only changes that can be directly observed in the brain or by standard laboratory tests of cognitive function, but also complex and knowledge-based aspects of intelligence, as well as cognitive aspects of the self, personality, and interpersonal functioning. In this conception, people adapt to changes in the body and in the social, cultural, and technological context of behavior in order to perform the tasks of living. Adequate cognitive functioning depends both on the integrity of neural systems and on these contextual factors.
This framework takes seriously recent understandings of plasticity. Neural decline in aging may not be as uniform or as profound as once believed, and various adaptive processes at the neural, behavioral, and social levels may mitigate the behavioral effects of the neural changes that do occur. To understand and assist the aging mind, it is necessary to consider changes in neural health and in behavioral context that occur in later life, as well as to understand inter-and intraindividual differences in cognitive function both cross-sectionally and over time.
We examined recent advances in the relevant science and identified three major areas in which scientific developments are creating significant opportunities for breakthroughs. The committee recommends that the NIA undertake major research initiatives in these three areas.
1. Neural Health. The NIA should undertake a major research initiative to build the scientific basis for promoting neural health in the aging brain.
Recent research shows that, contrary to a conventional belief, neural cell loss may not be the primary cause of cognitive decline in older people who are not suffering from Alzheimer's disease or related dementias. It suggests that aside from neural cell loss, changes in the health of neurons and neural networks play a major role in cognitive function. A new research focus on neural health in aging can improve basic understanding of the aging mind and lead to new health-maintaining interventions. A research initiative on neural health should consist of elements addressed to each of four major goals: developing quantitative functional and performance indicators, including behavioral tests, for neuronal health and neuronal dysfunction; identifying factors that affect neural health during the aging process, especially including imbalances in homeostatic processes, such as apoptosis, inflammation, and oxidative activity; devising interventions for the maintenance of healthy neu-