Enhanced choice for viewing cocaine pictures in cocaine addiction.
ABSTRACT Individuals with cocaine use disorder (CUD) chose cocaine over nondrug rewards. In two newly designed laboratory tasks with pictures, we document this modified choice outside of a cocaine administration paradigm.
Choice for viewing cocaine, pleasant, unpleasant, or neutral pictures--under explicit contingencies (choice made between two fully visible side-by-side images) and under more implicit contingencies (selections made between pictures hidden under flipped-over cards)--was examined in 20 CUD and 20 matched healthy control subjects. Subjects also provided self-reported ratings of each picture's pleasantness and arousal.
Under both contingencies, CUD subjects chose to view more cocaine pictures than control subjects, group differences that were not fully explained by the self-reported picture ratings. Furthermore, whereas CUD subjects' choice for viewing cocaine pictures exceeded choice for viewing unpleasant pictures (but did not exceed choice for viewing pleasant pictures, in contrast to their self-reported ratings), healthy control subjects avoided viewing cocaine pictures as frequently as, or even more than, unpleasant pictures. Finally, CUD subjects with the most cocaine viewing selections, even when directly compared with selections of the pleasant pictures, also reported the most frequent recent cocaine use.
Enhanced drug-related choice in cocaine addiction can be demonstrated even for nonpharmacologic (pictorial) stimuli. This choice, which is modulated by alternative stimuli, partly transcends self-reports (possibly indicative of a disconnect in cocaine addiction between self-reports and objective behavior) to provide an objective marker of addiction severity. Neuroimaging studies are needed to establish the neural underpinnings of such enhanced cocaine-related choice.
Article: Quantifying individual variation in the propensity to attribute incentive salience to reward cues.[show abstract] [hide abstract]
ABSTRACT: If reward-associated cues acquire the properties of incentive stimuli they can come to powerfully control behavior, and potentially promote maladaptive behavior. Pavlovian incentive stimuli are defined as stimuli that have three fundamental properties: they are attractive, they are themselves desired, and they can spur instrumental actions. We have found, however, that there is considerable individual variation in the extent to which animals attribute Pavlovian incentive motivational properties ("incentive salience") to reward cues. The purpose of this paper was to develop criteria for identifying and classifying individuals based on their propensity to attribute incentive salience to reward cues. To do this, we conducted a meta-analysis of a large sample of rats (N = 1,878) subjected to a classic Pavlovian conditioning procedure. We then used the propensity of animals to approach a cue predictive of reward (one index of the extent to which the cue was attributed with incentive salience), to characterize two behavioral phenotypes in this population: animals that approached the cue ("sign-trackers") vs. others that approached the location of reward delivery ("goal-trackers"). This variation in Pavlovian approach behavior predicted other behavioral indices of the propensity to attribute incentive salience to reward cues. Thus, the procedures reported here should be useful for making comparisons across studies and for assessing individual variation in incentive salience attribution in small samples of the population, or even for classifying single animals.PLoS ONE 01/2012; 7(6):e38987. · 4.09 Impact Factor