Does executive control really play a crucial role in explaining age-related cognitive and neural differences?

OBJECTIVE: The present study investigated the role of executive control in accounting for the cognitive and electrophysiological alterations occurring in healthy aging.

METHOD: Younger and older adults performed the inhibitory control task (ICT), a task composed of 3 types of trials that vary in the degree and kind of executive control subprocesses required. We analyzed event-related potentials (ERPs) elicited by these ICT trials and focused on the ERP components related to executive control subprocesses: P3b (updating), no-go P3 (inhibition), and reorienting negativity (RON; shifting).

RESULTS: Compared with younger adults, older adults exhibited worse performance on the ICT and a delay in the latency of all the ERPs investigated. These age-related differences occurred regardless of the amount of executive control required because they were not influenced by the type of trial. The RON amplitude, an index of shifting, was found markedly attenuated in older adults relative to younger adults.

CONCLUSIONS: Executive control, as a unitary function, cannot explain the age-related differences observed, which are more likely to reflect a general slowing of processes with aging. However, when we take into account the specific subprocesses of executive control, the one that seems to be particularly affected by aging is shifting, as revealed by the age-related alterations in the RON parameters.