Association for Behavior Analysis International

Electronic cigarettes (e-cigarettes) have been marketed as nicotine delivery devices that reduce the toxic effects of cigarette smoking; however, there is a paucity of research literature about these devices. The present study used the Multiple Choice Procedure (MCP) to evaluate the reinforcing value of e-cigarettes among nicotine-dependent smokers when compared to money or use of their usual cigarette. Participants completed two smoking sessions (cigarette and e-cigarette) and three MCP sessions where they chose between cigarette, e-cigarette, and money. Subjective ratings of smoking effects were also obtained using the original and adapted versions of the Direct Effects of Smoking Scale. 23 e-cigarette nave adults who were not attempting to quit smoking were evaluated. Results indicated significantly higher levels of self-reported direct effects of smoking the cigarette than the e-cigarette when in acute nicotine withdrawal. 74% of participants reported they preferred their regular cigarette brand to the e-cigarette. Preliminary results indicated that the crossover value on the MCP was higher for cigarette (M = $3.45) than e-cigarette (M = $2.74), suggesting participants found cigarettes to have a higher reinforcing value. Results of this pilot study will be used to inform future behavioral (e.g. contingency management analog studies) and pharmacological studies with e-cigarettes.

Few studies have functionally evaluated extinction of the discriminative stimulus functions of interoceptive stimulus control with drug states. The current study assessed extinction of a nicotine (0.3 mg/kg) vs. saline discrimination. 32 rats were trained to respond differentially between nicotine and saline. For 16 rats nicotine functioned as SD for reinforcement (3 pellets) of nose pokes (VI-30 sec) on some sessions, whereas saline functioned as S-delta for non-reinforcement on alternating sessions. The stimulus roles were counterbalanced for the remaining 16 rats. 16 rats then received a diminishing reinforcer magnitude over 16 sessions (2 pellets then 1 pellet) in the SD condition. The reinforcer magnitude was held constant for the other 16 rats. All 32 rats underwent explicit extinction training in both interoceptive conditions and were then tested immediately or following a 5-day delay. There were no differences between groups and no differences as a function of the delay for spontaneous recovery. Two weeks later there was no further evidence of spontaneous recovery. 3-pellets at the start of the final 4 sessions reinstated discriminated responding. Most interestingly, the S-delta state inhibited reinstated responding. The data show temporal stability in extinction of the discriminative stimulus effects of nicotine.

Four OVX rats were provided one hour access to an alcohol solution either during an FI 30 food schedule (polydipsia) or while in their homecage. On selected days rats were injected with peanut oil (vehicle) or estradiol (.02-15 ug/kg) in peanut oil. Polydipsic alcohol consumption was nearly twice the amount as homecage consumption. Administration of estradiol did not increase either polydipsic or homecage consumption of alcohol, instead slight decreases in alcohol consumption resulted.

Non-pharmacological variables play an important role on tolerance. Associative tolerance theories explain its development, when the administration of a drug is associated with a specific context. The objective of the present experiment was to evaluate the associative tolerance to the sedation effect of ethanol (E) in Male Wistar rats (200 g). Ss were assigned to three independent groups: saline group (S), pretreated with ip injections for 14 days (1.5 ml/kg). Two groups received 14 trials of the association of E, in same context of laboratory (L); all groups were injected on day 15 with ethanol (L), to a contextual sign (noise of 70 db). Latency of sedative response was recorded. Testing abstinence syndrome was made three days after tolerance test (day 18), following same procedure, except E administration. Results demonstrated that associative tolerance to sedation response to E depends on the context where it is tested. Influence of contextual clues and chronic treatment in loss of tolerance, is a major conclusion. Also, strong implications emerged, such as the importance of context signs in availability of the drug, in maintaining its use, and in shooting relapses during abstinence period; this might difficult treatment for controlling the use of any kind of drug.

Several procedures have been developed to establish ethanol drinking in rodents. Two commonly used are the "sucrose-fading" procedure (Samson, 1986) and the intermittent-access procedure (Simms et al., 2009). Though both procedures have advocates, there is little work directly comparing their effects. The purpose of the present experiment was to compare the procedures in a within-subject design. Six rats were trained to drink a 16% (w/v) ethanol solution via intermittent access; ethanol was available in the home cage 24 hrs per day for 3days each week. Once rats began drinking reliably, rats were moved to lickometers to measure drinking and the daily access reduced to 8% ethanol for 30 min per day. After 30 days, rats were exposed to a sucrose fading procedure, where 10% (w/v) sucrose was added to ethanol and faded out completely over ten sessions. Following intermittent access, rats drank pharmacologically active doses of ethanol (0.5 g/kg per 30 min). Addition of sucrose substantially increased intake. Interestingly, as sucrose was faded from the solution, intake levels dropped below those established via intermittent access and did not recover after 30 days. The results suggest that training with sucrose may be detrimental to alcohol initiation in rodents.

Impulsive choice is often examined using a delay-discounting procedure where choice is between2 reinforcers of different magnitudes presented at varying delays. Individual discounting rates can be influenced by many factors, including the addition of a response requirement to both alternatives. The current experiment used a modified Evenden and Ryan (1996) procedure, and choice was examined under conditions where the response requirement for both outcomes was a small fixed interval (FI 0 s), an intermediate FI (FI x/2 s), and a large FI (FI x s). Steeper discounting functions were obtained when the small FI was in effect, shallower functions were obtained when the large FI was in effect, and intermediate functions were obtained when the intermediate FI was in effect. This suggests that manipulating response requirement within this procedure can generate different rates of discounting within subjects. Different baseline rates of discounting have been shown to determine effects of stimulant drugs on impulsive choice using between-subjects designs. Generating different rates of discounting within subjects allows examination of drug effects on different baseline rates of discounting using a within-subject design. Therefore, acute effects of d-amphetamine on choice were examined upon replication of the small and large FI requirements.

The unilateral rat model of Parkinson's disease (PD) consists of chemically lesioning the substantia nigra (SN) of the right or left hemisphere. In the present study, hemi-parkinsonian rats (n = 8) were produced using 6-hydroxydopamine (6-OHDA). After recovery, rats were tested for rotational bias following d-Amphetamine injections (1.78 mg/kg). After bias testing, rats underwent 17 1-hour sessions of behavioral acqusition and maintenance, using reinforcement, of full rotations (360 degree turns) to the side of the observed bias. Reinforcement via successive approximations was delivered until the rotational behavior was acquired. Once the behavior was acquired it was maintained under a continuous reinforcement (CRF) schedule. Rats were deprived of water between 24 and 35 hours prior to each training session. Following the 17 sessions, the number of rotations was observed under 3 conditions: CRF without d-amphetamine, CRF and lowdose d-Amphetamine (0.56 mg/kg), and d-Amphetamine (1.78 mg/kg) alone. It was found that the CRF and low dose d-Amphetamine produced considerably more correct responses than either the CRF or the d-Amphetamine (1.78 mg/kg) test, F(2,12) = 8.4,P < 0.05. The results of the study suggest that reinforcement can be considered as part of the treatment for disorders such as PD and may contribute to a reduction in drug treatment.

Research suggests that heroin users and individuals with a prior history of heroine dependence tend to be more aggressive than nonusers. This has been shown in crime statistics, and in studies using aggression questionnaires, psychometric measures of aggression, and laboratory behavioral tasks, including the Point Subtraction Aggression Paradigm (PSAP). On the PSAP, participants are paired with a hypothetical partner and can respond to subtract money from their partner's earnings. In such studies, heroin addicts make more aggressive responses against a hypothetical partner than controls (i.e., more frequently subtract money from their partner's earnings). The present study was intended to investigate whether mild opioid withdrawal affects aggression by examining performance in12 clients (N = 12) currently undergoing methadone therapy. Participants responded on the PSAP task to earn money toward gift certificates. Behavior on the PSAP was measured once prior to and once following the participant's daily methadone dose, and rates of aggressive responding were compared across the2 time periods. Results show that participants did not respond more aggressively on the PSAP task pre-dose as expected; however, they did score higher on the aggression scale of the Profile of Mood States Questionnaire. There was also a positive relationship between number of sessions and money earning responses.

Studies in social transmission of food preference have shown reliable serial position functions in Long Evans rats. Functions may show primacy or recency depending of different parameter values. In these studies, a demonstrator rat that has consumed flavored food will increase preference for that flavor in nave observer rats. Studies in behavioral pharmacology have shown that cholinergic antagonists may produce deficits in acquisition and recall in different tasks. In this experiment Control and Saline Groups were compared with 3 different groups in which 4, 8, and 16 mg/kg ip of scopolamine were administered after demonstration. Testing was made after 24 hr. Groups were formed by 12 observers that interacted with a list of three demonstrators that have eaten different flavored foods, with position counterbalanced. Results showed that with the 4 mg dose primacy and recency were observed, with the 8 mg/kg dose recency was observed and with the 16 mg/kg dose neither effect was observed, a flat curve was produced. Repeated measures ANOVA showed a reliable serial position effect, quadratic contrast for serial position and linear interaction for serial position and group. The drug effect changed the functions of the drug groups from a primacy-recency to an absence of effect.

Three rats were administered a convulsant dose of pilocarpine (i.p.) on postnatal day 20, provoking a 6 hour seizure; 4 control animals were administered saline. When the animals were adults, they were trained on auditory location and quality discriminations. Two speakers were located on a wall opposite a wall with a liquid dipper feeder. A lever was located adjacent to each speaker. The location discrimination used a go-right/go-left procedure and broad band noise bursts signaled the location of the correct response site. The location of the stimuli alternated randomly on either side across trials. The seizure animals displayed marked impairments in auditory localization (Neill et al. 2005). Further training was carried out using a simultaneous auditory quality discrimination procedure (Harrison, 1990): two stimuli were presented on each trial, a broad band noise burst through one speaker and a 2-kHz complex signal through the other. The seizure animals were able to acquire the quality discrimination to a criterion of 90% or better. When the location discrimination was reintroduced, seizure animals performed as well as controls. The naturalistic simultaneous quality discrimination procedure permitted neurologically-impaired subjects to acquire quality discriminations, and had the unexpected advantage of improving auditory location discrimination in such subjects.

It is thought that serotonin (5-HT) plays a role in impulsive choice although studies examining the effects have yielded mixed results. This study examined the effects of 5-HT1A receptor agonist 8-OH-DPAT on delay discounting in pigeons. Four pigeons were tested on a discrete-trials delayed reinforcement task in which they choose 1.5-s access to food or 4-s access to food that was either available immediately or after a delay. The delay was progressively increased within sessions from 0 s to 48 s. Once response choice stabilized for individual subjects, pigeons were tested in different sessions with saline and with 0.1, 0.32, 1.0, and 3.2 mg/kg of 8-OH-DPAT. In sessions preceded by saline, pigeons responded for the larger reinforcer when there was no delay and responded progressively less as delay increased. The effects of 8-OH-DPAT on delay discounting were variable among although consistent within subjects, decreasing discounting in some pigeons and increasing discounting in others. Latency was increased by injection of 8-OH-DPAT in all pigeons. The 5-HT1A receptor antagonist WAY100635 antagonized the effects of 8-OH-DPAT on delay discounting and on latency. These results parallel data which fail to provide clear evidence for a prominent role of 5-HT1A receptors in impulsive choice

Studies in social transmission of food preference have shown reliable serial position functions in Long Evans rats. Functions may show primacy or recency depending of different parameter values. In these studies, a demonstrator rat that has consumed flavored food will increase preference for that flavor in nave observer rats. Studies in behavioral pharmacology have shown that cholinergic antagonists may produce deficits in acquisition and recall in different tasks. In this experiment Control and Saline Groups were compared with 2 different groups in which 3.75 and 7.5 mg/kg of Atropine were administered ip. Testing was made after 24 hr. Groups were formed by 12 observers that interacted with a list of three demonstrators that have eaten different flavored foods, with position counterbalanced. Results showed that both curves were different from the Control Group. The first and third positions were not recalled as the second one. The 7.5 mg/kg curve was more pronounced than the 3.75 mg/kg curve. Repeated measures ANOVA showed a reliable interaction between serial position and group. Planned contrasts showed a reliable linear contrast and a reliable quadratic interaction between serial position and group. The effect of Atropine eliminated the serial effects seen in the Control Group.

The Therapeutic Workplace is an employment-based drug abuse treatment that provides paid employment contingent upon verification of drug abstinence with urinalysis screens. While shown to be effective and reducing drug use, the treatment requires that participants willingly remain employed in a workplace requiring regular urine drug screens. In the present experiment, unemployed heroin-dependent adults were asked to make choices between employment opportunities of varying wage rates that either did or did not require mandatory urine testing as a condition of employment. Indifference points between the two employment options were calculated to quantify the relative change in value that added urinalysis contingencies imposed. Results indicate that the median wage required for a participant to take a job requiring urinalysis screens was only 4% higher than the job not requiring urinalysis screens, indicating near indifference between the two options. Furthermore, choices indicate that nearly one third of participants actually prefer a job requiring urinalysis screens, and these employment choices were related to self-reported recent heroin use. In conclusion, employment-based drug treatment that requires urinalysis screens is a viable treatment option among unemployed heroin-dependent adults.

The olfactory span task involves an incrementing non matching-to-sample (INMTS) in which an increasing number of sample stimuli control behavior. The present study explored the utility of the INMTS procedure as a baseline for behavioral pharmacology in rats. Rats were placed in a circular arena with 18 stimulus locations. In the initial trial of each session, one stimulus cup marked with a distinct olfactory stimulus was present and responding to it was reinforced. Each subsequent trial added a new olfactory stimulus and responding to the new stimulus was always reinforced (non matching). Each session included 24 trials of the INMTS task as well as a performance control task involving a simple olfactory discrimination to control for any non mnemonic drug effects. Once responding met stability criteria, subjects were given twice weekly i.p. injections of methamphetamine or methylphenidate prior to the testing session. Both drugs produced significant impairments on span, longest run, and accuracy at the highest doses.