When Desire Collides with Reason: Functional Interactions between Anteroventral Prefrontal Cortex and Nucleus Accumbens Underlie the Human Ability to Resist Impulsive Desires

Experimental design of sequential forced-choice task. A, Desire context: subjects were free to select the conditioned stimulus (i.e., to follow previously acquired stimulus–response–reward associations) if this particular stimulus was not part of the target set. This allowed participants to acquire immediate reward as a bonus during pursuit of the superordinate long-term task goal. B, Desire–reason dilemma: subjects had to counteract the behavioral bias oriented toward immediate reward during accomplishment of the superordinate task goal. The conditioned stimulus was part of the target set. Participants had to collect it once, after its first appearance within the current block. When it occurred a second time in the same block, they were required to reject it, because it had already been collected (see Materials and Methods, Task procedure). Subjects thus had to abandon one bonus point to achieve the superordinate long-term task goal (i.e., 4 points at the end of a block), which required a successful resolution of the desire–reason dilemma. L, Left; R, right.