absolute or relative (or normalized) values)23. It may also be related to drug-induced craving effects: with drugs like cocaine, craving in addicted individuals increases 10–15 minutes after smoking, whereas the studies discussed above reported decreases in craving immediately after nicotine or heroin administration. Viewed in this light, and consistent with our model, the collective results suggest that when drug intake decreases craving, this is associated with decreases in drug-related PFC activity, and vice versa. Concomitantly with these drug-related decreases, we would expect non-drug related PFC activity to increase, as indeed is the case (see below).
