There is a piece in the Scientific American by W. Herbert on the work of I. Senay on willingness verses willfulness (here).

Willingness is a core concept of addiction recovery programs—and a paradoxical one. Twelve-step programs emphasize that addicts cannot will themselves into healthy sobriety—indeed, that ego and self-reliance are often a root cause of their problem. Yet recovering addicts must be willing. That is, they must be open to the possibility that the group and its principles are powerful enough to trump a compulsive disease…(I. Senay) figured out an intriguing way to create a laboratory version of both willfulness and willingness—and to explore possible connections to intention, motivation and goal-directed actions. In short, he identified some key traits needed not only for long-term abstinence but for any personal objective, from losing weight to learning to play guitar.

Senay did this by exploring self-talk. Self-talk is just what it sounds like—that voice in your head that articulates what you are thinking, spelling out your options and intentions and hopes and fears, and so forth. It is the ongoing conversation you have with yourself. Senay thought that the form and texture of self-talk—right down to the sentence structure—might be important in shaping plans and actions. What’s more, self-talk might be a tool for exerting the will—or being willing….

(in a priming experiment) those primed with the interrogative phrase “Will I?” expressed a much greater commitment to exercise regularly than did those primed with the declarative phrase “I will.” What’s more, when the volunteers were questioned about why they felt they would be newly motivated to get to the gym more often, those primed with the question said things like: “Because I want to take more responsibility for my own health.” Those primed with “I will” offered strikingly different explanations, such as: “Because I would feel guilty or ashamed of myself if I did not.” This last finding is crucial. It indicates that those with questioning minds were more intrinsically motivated to change.

This idea that the way we talk to ourselves is the way we establish motivation is extremely interesting. It fits with a notion that some things are accomplished by passing through consciousness and therefore being generally accessible to the whole brain.