Behavioral and electrophysiological correlates of training-induced cognitive control improvements.

Cognitive control--the ability to exert control over thoughts, attention and behavior in order to achieve a goal--is essential to adaptive functioning and its disruption characterizes various neuropsychiatric and neurodegenerative disorders. In recent years, increased attention has been devoted to investigating the effects of training on performance and brain function, but little is known about whether cognitive control can be improved through training. To fill this gap, we designed a brief training targeting various components of cognitive control, including conflict monitoring and interference resolution. Twenty participants performed a 3-day training protocol, preceded and followed by identical pre- and post-training sessions, respectively, which included event-related potential (ERP) recordings. To detect transfer effects, the training and pre-/post-training sessions employed different tasks hypothesized to rely on similar interference resolution mechanisms. We hypothesized that training would selectively improve performance for high-interference (i.e., incongruent) trials and be associated with reduced amplitudes in the N2 component, a waveform known to index interference. Trial-to-trial behavioral adjustments were also analyzed to assess potential mechanisms of training-induced improvements. Relative to pre-training, participants showed reduced reaction time (RT) and N2 amplitude for incongruent, but not congruent, trials, suggesting improved interference resolution. Critically, participants showing the greatest reductions in interference effects during the course of the training displayed the largest pre- to post-training reductions in N2 amplitudes in a separate task, highlighting transfer effects. Overall, results suggest that a brief training can improve cognitive control, specifically the ability to inhibit task-irrelevant information.