Abstract: The relations between speed and performance in five tasks, including Digit Rota- tion, Mental Arithmetic, Symbol-Digit, Chinese Character-Digit, and Figure Spatial Location, was studied in the young group (20-29 years of age, 50 subjects) and old group (60-69 years of age, 50 subjects) by using cumulate performance-reaction time curve. The results indicated: (1 ) The cumulate performance-reaction time curve of five tasks progressed more slowly up in the old group than in the young group, suggesting that the old group took longer reaction time to get the cumulate performance corresponding to the young group; (2) The characteristic of cumulate performance-reaction time curve going up had a relation to feature and difficulty of tasks. These results showed that speed slowing ensured the old group to get performance corresponding to the young group within the difficulty of these tasks, supporting the viewpoint in which speed perhaps played a regulating role between age and performance

Key words: Speed, Cognitive performance, Age