Motivation drives humans to attain desired goals or objects by enhancing our attention, facilitating faster physical movement, and reinforcing behaviors that lead to goal acquisition. Behavioral and physiological studies find evidence for this effect by manipulating extrinsic motivation using pre-goal states and implementing rewards. Further research on motivation suggests intrinsic motivation also has similar behavioral effects to extrinsic motivation. The current studies examined whether performance expectancy and autonomy enhance motivation using behavioral and electroencephalography (EEG) measures. Study 1 manipulated performance expectations that a flanker task would be difficult or easy based on a social comparison. Study 2 manipulated autonomy by giving participants a choice of task and self-controlled feedback. Study 1 results revealed greater neural motor-action preparation and feedback processing to difficult (vs. easy) expectancy trials. Difficult expectancy also narrowed attention but did not reveal performance differences with RT. Participants also self-reported marginally greater high-approach motivation during difficult (vs. easy) expectancy. Study 2 results revealed no difference in neural motor-action preparation and feedback processing to autonomy (vs. no autonomy). Autonomy also broadened (rather than narrowed) attention. Autonomy also increased response times to a flanker task. Participants self-reported marginally more low-approach motivation during autonomy (vs. no autonomy). Taken together, results suggest not all forms of intrinsic motivation influence motivation in similar ways. Based on neural and behavioral measures, it seems performance expectancy enhances high motivational intensity, while autonomy enhances low motivational intensity.