Abstract: Executive decline hypothesis of cognitive aging is an attractive theory proposed in recent years. However, there are some obstacles when put this theory into practice, which including the diversity of executive functions, the reliability and validity of executive function measures, and the relationship between executive function and processing speed. At present, the focuses of the research are whether executive function mediates age differences in cognition after processing speed have been taken into account on behavior level, and which role does it play as brain remodeling with age on neural level. To explore the essence of cognitive aging, we should connect cognitive aging with the brain, and emphasize general mechanism as well as selective changes of the cognitive system.

Key words: cognition, age, processing speed, executive function, executive decline hypothesis