Dorsolateral Prefrontal Cortex Activity during a Brain Training Game Predicts Cognitive Improvements after Four Weeks' Brain Training Game Intervention: Evidence from a Randomized Controlled Trial

Background: Recent studies have demonstrated that brain activities using NIRS (near-infrared spectroscopy) at baseline during cognitive tasks (e.g., N-back task) can predict the cognitive benefits of a cognitive training. In this study, we investigated whether brain activities during brain training game (BT) at baseline would predict benefits to cognitive functions after the intervention period. Methods: In a four-week double-blinded randomized control trial (RCT) 72 young adults were randomly assigned to one of the two groups: participants in the BT group played specific game, called the Brain Age. Participants in an active control group (ACT) played the puzzle game Tetris. We measured brain activity during the training games using two channel NIRS before the intervention period. Cognitive functions were tested before and after the four-week intervention period. Results: The BT showed significant improvements in inhibition, processing speed, and working memory performance compared to ACT. The left and right DLPFC (dorsolateral prefrontal cortex) brain activities during the BT at baseline were associated with improvements in inhibition and processing speed. Discussion: This randomized control trial first provides scientific evidence that DLPFC activities during BT at baseline can predict cognitive improvements after a four-week intervention period.