Models of aging and neuropsychological test performance decline with aging

While some researchers have claimed that normal aging need not be accompanied by significant neuropsychological deficits ("preserved function" models), others have asserted that aging is associated with significant deficits in either specific or general cognitive functioning ("specific" vs "general" decline models). Among the significant decline models, there is disagreement regarding which functions are affected and to what degree, and at what point in the normal life span such a decline becomes significant. This study examined the neuropsychological test performance of 86 adults with no objective evidence of brain dysfunction. Significant decline, beginning as early as the 30s or 40s, was seen on all measures except the simple motor task of finger tapping. These results are viewed as supporting a model of differential decline of specific functions nested within a general decline model.