OBJECTIVES: Decline in cognitive control is one of the primary cognitive changes in normal aging. Reaching a consensus regarding the nature of these age-related changes, however, is complicated by the complexity of cognitive control as a construct. METHODS: Healthy older and younger adults participated in a multifactorial test of cognitive control. Within participants, the procedure varied as a function of the amount contextual load, episodic load, and response-conflict load present. RESULTS: We found that older adults showed impaired performance relative to younger adults. We also found, however, that the response selection process underlying the response-conflict manipulation was a major moderator of age-related differences in both the contextual and episodic load conditions-suggesting a hierarchical organization. DISCUSSION: These findings are consistent with previous findings, suggesting that deficits in cognitive control in older adults are directly related to the resolution of response-conflict and that other apparent deficits may be derivative upon the more basic response-conflict related deficit
