these contexts and environments (Fiske et al., 1998). Note in this context that ''old age" is relatively new as a cultural phenomenon and that as longevity and quality of life for older adults increase, the cultural and social aspects of old age are likely to continue changing.

RECENT SCIENTIFIC DEVELOPMENTS

Recent scientific developments in understanding the aging mind suggest the need to expand research to pay more careful attention to various aspects of the contexts of aging minds. Most important are four growing bodies of evidence: (1) that life experience can change the brain; (2) that individuals adapt in various ways to maintain cognitive functioning and task performance in the face of changes in the brain and in their social contexts; (3) that systematically different life experiences yield systematically different cognitive contents and processes; (4) and that advanced technology can modify the context of cognition to greatly improve functioning for older people.

Neurobiology of Life Experience

The coevolution of brain and culture has long been recognized in the study of human evolution (e.g., Durham, 1991), in which there has been some joining of developmental neuroscience and the behavioral-social developmental sciences. More recently, evidence of neural plasticity has revealed the importance of experiences within an individual's life span as a cause of change in the brain. The concept of "experience" was initially identified as a determining or modulating factor of brain development (e.g., Squire and Kandel, 1999). For example, in developmental work on perception, many studies demonstrated that certain aspects of brain development (such as the size of function-specific locations and the complexity and density of synaptic and dendritic architectures) are conditioned by the nature of early "sensory-input" experiences, such as the richness of an animal's environment (Merzenich and Sameshima, 1993; Kolb and Whishaw, 1998). In addition, experimental studies have shown that training in specific tasks also affects brain structure (see Kolb and Whishaw, 1998, for a review). A good recent example, though nonexperimental, is the finding that players of stringed instruments of the violin family have a larger cortical representation of the fingers of the left hand than of the right hand and that this is particularly true of string players who began musical practice before age 13 (Elbert et al., 1995). The presumed reason is that in playing these instruments, the fingers of the left hand are manipulated individually while those of the right hand, which holds the bow, move together. The evidence suggests that architecture in this area of the brain may be more plastic before age 13. These findings demonstrate links among enriching experiences, improved performance, and change



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