Age-related differences in the recruitment of proactive and reactive control in a situation of sustained attention.

We examined ERP indices of proactive and reactive cognitive control processes in younger and older adults performing a sustained attention Go/No-Go task. Behavioral results showed that older adults were able to maintain a stable level of performance over time, while younger adults exhibited a vigilance decrement. The main ERP findings showed that in older adults, the amplitude of the pre-stimulus slow wave, a marker of proactive control, remained stable with time on task, and that the amplitude of the sustained potential, a marker of reactive control, increased with time on task. On the other hand, in younger adults, the amplitudes of both components decreased over time. Overall, older participants also exhibited larger amplitudes of the error negativity than their younger counterparts. These results suggest that age-related differences in the recruitment of proactive and reactive control over the course of the task can explain age differences in sustained attention performance.