The Go-NoGo phase followed the Pre-Potent Go phase. During the Go-NoGo phase, the ‘Go’ trials were interspersed with ‘NoGo’ trials; these appeared as number lures. Pressing the space bar was the required response upon viewing a number lure. During the Go-NoGo phase, X and Y were presented randomly, interspersed with number lures, such that the predictable alternating sequence was disrupted. Responses were required only if a Y appeared after an X or viceversa, and therefore the participant must inhibit the established pre-potent response in all other trials.