Association for Behavior Analysis International

This symposium will feature basic and human laboratory research, as well as research conducted in naturalistic settings, all centered on health behavior. The topics to be addressed include historical variables that predict delay discounting and drug self-administration, mechanisms underlying the relation between substance abuse and sexual risk behavior, and contingency management approaches to reduce cigarette smoking. Jeff Stein will discuss effects of pre-exposure to reinforcement delays on discounting and alcohol/sucrose self-administration. Patrick Johnson will discuss effects of alcohol and oral methamphetamine on delayed and probabilistic hypothetical sexual outcomes. Allison Kurti will discuss the effects of a combined (exercise plus contingency management) behavioral intervention to reduce cigarette smoking relative to its independent components. Finally, Paul Romanowich will discuss effects of different incentive schedules on the initiation and maintenance of smoking abstinence in hard-to-treat smokers.

In humans, high levels of impulsive choice (delay discounting) are associated with drug abuse and dependence. In rodents, similar impulsive-choice measures are associated with greater drug self-administration (SA) across a range of experimental paradigms (e.g., acquisition, escalation, and reinstatement of drug SA). Together, these findings implybut do not confirmthat impulsive choice (or its underlying neurobiology) predisposes organisms toward drug vulnerability. With few exceptions, however, this possibility has not been subjected to experimentation (i.e., determining whether experimental changes in impulsive choice produce predictable changes on drug SA, or vice versa). In this ongoing research line, we have sought to develop and refine an historical treatment variable (prolonged pre-exposure to reinforcement delay, or PPRD) to: (a) reduce impulsive choice in rats, and (b) evaluate its concomitant effects on subsequent drug self-administration. Across two experiments, PPRD has reduced impulsive choice in delay-exposed (DE; n = 62) compared to delay-nave (DN; n = 46) rats. Topics for discussion will include: potential mechanisms of PPRDs effect on impulsive choice, generality of this effect across time and intervening experience, and preliminary examinations (and interpretation) of post-PPRD alcohol and sucrose self-administration.

Substance abuse is associated with increased likelihood of engagement in sexual risk behavior, which may increase vulnerability to transmission of sexually transmitted infections (STIs). One possible mechanism underlying the relation between substance abuse and sexual risk behavior is steep discounting of delayed or probabilistic outcomes. In an attempt to model the acute effects of commonly abused substances on discounting, we are administering oral methamphetamine (20 & 40 mg) or oral alcohol (1 g/kg) to recreational users in two independent within-subject, double-blind, placebo-controlled laboratory studies. On session days, participants are administered a placebo or active dose and are asked to complete tasks assessing discounting of delayed or probabilistic hypothetical sexual outcomes. In both tasks, participants are given repeated hypothetical choices between unprotected or protected sex (i.e., with a condom) with self-selected photographed individuals. The tasks differ in that either condom access is delayed (delay discounting) or unprotected sex results probabilistically in STI infection (probability discounting). Data collected thus far reveal a pattern of steeper discounting of condom-protected sex in alcohol (n = 10), but not methamphetamine (n = 8), sessions relative to discounting in placebo sessions. Important individual differences in drug effects and their implications for public health will be discussed.

Innovative smoking cessation interventions may be inspired by a behavioral economic view of addiction, which suggests that cessation may be promoted by increasing the reinforcing value of abstinence, decreasing the reinforcing value of smoking, or both. Previous work conducted in our laboratory, in which exercise decreased smoking motivation and increased the latency to smoke, suggests that exercise may decrease the value of smoking. One treatment that increases the value of abstaining is contingency management. This work assessed the effects of a combined (exercise plus CM) approach to smoking reduction, and the mechanisms through which its effects were achieved. Thus far, 12 smokers (targeted N= 20) have undergone the following sessions: (1) CM + exercise, (2) CM control (non-contingent incentives) + exercise, (3) CM + non-exercise, (4) CM control + non-exercise. Results to date indicate a main effect of CM, in that latencies to smoke (in min) are longer after CM (M= 15.2) versus CM-control conditions (5.4). Exercise also decreases smoking reinforcement (M= 33% decrease in global QSU score; Cox et al., 2001) relative to non-exercise (27% increase). Mediation analyses will be conducted to assess whether effects of exercise on smoking are mediated through smoking motivation and/or temporal discounting.

Percentile incentive schedules have increased abstinence in hart-to-treat (HTT) smokers, relative to escalating incentive schedules. However, participants receiving incentives on a percentile schedule typically earn more for their first abstinent breath carbon monoxide (BCO) sample, relative to participants in equivalent escalating incentive schedules. Many studies have shown that larger incentive magnitude increases abstinence rates. The present study tested whether the magnitude of the first abstinent BCO sample caused differential rates of abstinence initiation and maintenance in 93 HTT smokers. Smokers were randomized to either percentile, escalating, or random incentive schedules. The magnitude of the first abstinence BCO sample (< 3 ppm) was held constant at $5.00 for participants in the percentile and escalating incentive schedule groups. Results showed similar patterns of abstinence initiation between the percentile and escalating incentive groups (percentile = 64%; escalating = 66%). However, Figure 1 shows that once initiated, abstinence was more likely to be maintained by escalating incentive participants. Percentile group participants were no better than random incentive participants at maintaining abstinence. In HTT smokers, the magnitude of the first abstinent BCO sample seems to be responsible for the better outcomes (both abstinence initiation and maintenance) previously observed for percentile incentive schedules.