Neuroscientific systems research shows that the striatum and ventromedial prefrontal cortex represent the value of an action and influence prediction-error signaling (Fig. 4), functions that are critical for decision making.47 This research requires the participant to learn to differentiate rewarding from punishing stimuli by pressing a button after exposure to one type of stimulus and not pressing the button after exposure to the other type of stimulus. In such research, the participant is said to appropriately represent value when the participant has learned the corresponding rewarding and punishing consequences that follow from either pressing or not pressing the button after exposure to each stimulus. Before learning these stimulus–response contingencies, the participant cannot represent value and hence cannot predict the occurrence of rewards and punishments. In this context, receipt of an unexpected reward elicits a brain response known as a positive prediction error, indicating that an event is more rewarding than expected. Conversely, failure to receive an expected reward elicits a response known as a negative prediction error, indicating that an event is less rewarding than expected. In such research, youth
