Private speech amount positively predicts memory performance in young adults

This study used a card-matching game that relies on visual-spatial working memory to investigate whether the amount one talks out loud to themselves (referred to as private speech) predicts cognitive performance in young adults (n = 118, mean age = 20.13 years). Each participant's performance was measured in two "Private Speech" trials, in which they were instructed to complete the game efficiently, while using private speech as much as they can. Using multilevel modeling, we found that participants performed significantly better on trials for which they produced more private speech. This relationship was not moderated by baseline competency on the task (measured in a condition where participants were not instructed to use, and rarely ever used, private speech). The study shows that the degree to which adults use private speech - when instructed to do so, is associated with cognitive performance, which may have important implications for educational/instructional settings.