The premotor role of the prefrontal cortex in response consistency.

OBJECTIVE

The aim of the present study was to investigate the cortical correlates of the intraindividual coefficient of variation (ICV) in a go/no-go task, focusing on the prefrontal cortex (PFC) contribution and evaluating both pre- and poststimulus brain activity.

METHOD

We recorded event-related potentials (ERPs) in 40 subjects, arranged a posteriori in 2 groups on the basis of their ICV values. By this method, we formed the consistent (low ICV; n = 20) and inconsistent (high ICV; n = 20) group: the age, speed, and accuracy performance of the 2 groups were matched.

RESULTS

The prestimulus anticipatory PFC activity, as reflected by the prefrontal negativity (pN) wave, and the poststimulus P3 component were larger in the consistent than in the inconsistent group. In contrast, no differences were observed between groups in the brain activities associated to motor preparation and early sensory processing.

CONCLUSIONS

Data are interpreted as an enhanced top-down control in consistent performers, likely characterized by a greater sustained attention on the task.