Automatic Processes in Addiction: A Commentary

S ections 3 through 5 present a fascinating set of chapters on the many different psychological processes that may contribute to pathological drug-seeking behavior in addiction, with an emphasis on implicit automatic processes. We briefly address some highlights. The idea that addiction may result from dys-function that alters the balance among multiple different psychological processes, which normally occur simultaneously in encounter with rewards or predictive cues for them, is featured in several chapters. For example, whether an abstinent addict either relapses or continues to abstain at any given point in time may be the result of complex interactions among multiple cognitive and motiva-tional components, all of which may be activated by the same reward-related event. Thus, it is important to know the identity of the real components, differences between them, and the balance that controls behavior at any moment. Yin and Knowlton (Chapter 12) describe the differences between three major categories of psychological process that produce appetitive responses: cognitive act-outcome understanding, simpler S-R (stimulus-response) habits, and middle-level, Pavlovian-triggered appetitive motivational components, which can include attribution of incentive salience to reward-related conditioned stimuli and their neural representations. Yin and Knowlton (Chapter 12) discuss how these three mechanisms operate simultaneously in animals as well as people, and review evidence that they are mediated by different underlying neural systems. Franken et al. (Chapter 13) further survey human neuroimaging studies of reward-related processes, and note the importance of identifying brain activations triggered by reward stimuli that actually mediate reward. These must be distinguished from activation due to other simultaneously activated psychological processes, such as memory and attention. Such efforts will be critical to map psychological components of addiction onto their respective brain mechanisms.