The effects of task-relevant suggestions on motivated cognitive control.

To deal with the only constant in life, change, we use a set of top-down processes called cognitive control. Cognitive control enables us to develop new stimulus-response associations appropriate for the task at hand instead of being rigidly bound to our existing repertoire of responses. Given the central role cognitive control has in our lives, it is not a surprise that different methods have been tested for improving it; however, few have shown generalizable, long-term effects. One approach, which has shown great promise in enhancing performance in different tasks requiring cognitive control (e.g., Stroop, Simon, Flanker, Go-NoGo, and tone-monitoring tasks), is using task-relevant direct-verbal suggestions, including posthypnotic and nonhypnotic suggestions. The observed effects of suggestions are both reliable, as they have been replicated by different labs over three decades, and generalizable, as they have proven effective in enhancing different aspects of cognitive control, such as inhibition and working memory updating. In the current review, we discuss recent developments in the understanding of cognitive control and its hierarchies and elucidate the effects of suggestions on cognitive control and their underlying mechanisms. Finally, we argue that besides the applicability of task-relevant suggestions in training regimens for enhancing cognitive control, their effects have theoretical implications for conceptual questions regarding both motivated hierarchical cognitive control and hypnotic phenomena.