A normative perspective on motivation.

Understanding the effects of motivation on instrumental action selection, and specifically on its two main forms, goal-directed and habitual control, is fundamental to the study of decision making. Motivational states have been shown to 'direct' goal-directed behavior rather straightforwardly towards more valuable outcomes. However, how motivational states can influence outcome-insensitive habitual behavior is more mysterious. We adopt a normative perspective, assuming that animals seek to maximize the utilities they achieve, and viewing motivation as a mapping from outcomes to utilities. We suggest that habitual action selection can direct responding properly only in motivational states which pertained during behavioral training. However, in novel states, we propose that outcome-independent, global effects of the utilities can 'energize' habitual actions.