['Age-related cognitive decline might involve selective deterioration of specific brain systems. We studied the relationship between age and cognition by comparing cognitive function of older and younger high functioning men.', 'A cross-sectional study comparing neuropsychological test battery performance of younger (18-60 years) and older (61-85 years) men.', 'Older men showed impaired psychomotor speed, working memory, attention, declarative verbal memory and executive functions. Impairment in executive function was prominent and not explained by psychomotor slowing, impaired working memory or attention. Regression models showed a non-linear relationship between age and executive function with a change of slopes in the mid-50s. The relationship of age with verbal memory was linear.'] Is age in high-functioning healthy men associated with nonlinear decline in some 'executive ' functions in late middle age?