Age-related differences in supervisory attentional system functions.

The authors explored the effect of age on executive functions by using 3 tasks (Tower of London, Hayling, and Brixton tests) designed to assess specific executive processes (planning, inhibition, and abstraction of logical rules) that were also sensitive to frontal dysfunction. The performance of elderly participants (n = 48) was significantly poorer than that of young participants (n = 47) in all 3 tasks. Processing speed, measured by means of a color-naming task, explained some but not all of the age-related differences. These results are discussed in terms of general and specific factors in cognitive aging.