UC San Diego

The ability to control oneself in the face of temptation is crucial to everyday life. To successfully resist temptation, individuals use many different strategies, including amplifying a long-term goal, focusing attention elsewhere, and suppressing the provoked, inappropriate action tendency. Here, I focus on response suppression, which is highly tractable and has a well-defined neural circuitry. I specifically focus on response suppression in controlling motivationally driven action tendencies, which is a crucial element of real-world self-control that has often been ignored. In Chapter 1, I develop a new task that probes if and how response suppression is exerted in the face of a motivationally driven action tendency. Using neurophysiological measures, I show that response suppression plays a key role in controlling such provocations. In Chapter 2, I find that individuals can also control themselves by suppressing an effector in advance (i.e. proactively), thereby preventing an impending provocation. Then, in Chapter 3, I take advantage of the paradigm we developed in a sample of overweight individuals to examine excessive provocation versus diminished control, which our paradigm is designed to address. I show that individuals with high eating drive are less provoked by the motivating stimulus, suggesting that they adopt a safer, more proactive control strategy. In Chapter 4, I elucidate the temporal dynamics of when activation rises and when suppression kicks in. I also show how mental fatigue can diminish individuals’ ability to suppress high levels of activation. Finally, in Chapter 5, I examine another type of real-world provocation called motor affordances. I find that affordances depend on the excitatory/inhibitory state of the motor system, which is modulated by cognitive load. This indicates that the motor system can be “set” so that inappropriate provocations do not emerge, which may include motivationally driven provocations. Taken together, the current dissertation shows that both reactive and proactive response suppression play a pivotal role in controlling motivationally driven action tendencies. Importantly, it suggests that the control process relies on many factors, including the strength of the activation, recent “high conflict” exposures, motivational drive, mental fatigue, and the current state of the motor system.