"We can therefore take each EF that researchers have identified and redefine it as a type of self-direct action. Inhibition becomes self-restraint, self-awareness is self-directed attention, verbal working memory is self-speech (talking to yourself, usually using your mind’s voice), nonverbal working memory is seeing to yourself, or using visual imagery along with other forms of self-directed sensing (rehearing previous conversations to yourself, re-perceiving odors you previously smelled or flavors you previously tasted, etc.). And problem-solving could be thought of as self-directed play (taking apart and recombining things or ideas to create novel re-arrangements). By adulthood, all of these are largely invisible to others, or mental in form, such that the person engages in them privately, to themselves, in their mind (brain). Working memory and problem-solving in fact are the ways people typically mentally represent and manipulate information that is being held in our mind (using images and words)."

Russell A. Barkley