Four pigeons were exposed to second-order schedules of token reinforcement, with stimulus lights serving as token reinforcers. Tokens were earned according to a fixed-ratio (token-production) schedule, with the opportunity to exchange tokens for food (exchange period) occurring after a fixed number had been produced (exchange-production ratio). The token-production and exchange-production ...

RATIONALE: Combining strains to generate mutant mice may obscure conclusions regarding the targeted gene. Specifically, cocaine may have reduced reinforcing effects in 129 substrains compared to the C57BL/6 strain, commonly used for ES cells and breeding, respectively. OBJECTIVES: We tested the hypothesis that reinforcing effects of cocaine differ between the ...

The major problem in treating excessive eating is high rates of relapse to maladaptive eating habits during diet treatments; this relapse is often induced by stress or anxiety states. Preclinical studies have not explored this clinical problem. Here, we adapted a reinstatement model (commonly used to study relapse to abused ...

The central nucleus (CN) of the amygdala and basal forebrain cholinergic projections to the posterior parietal cortex (PPC) are involved in regulating changes in attentional processing of conditioned stimuli. In a previous study, lesions of the CN produced a deficit in conditioned orienting behavior (rearing on the hind legs) when ...

This study tested the independent and interactive effects of anxiety and dietary restraint on the relative reinforcing value of snack food. Thirty non-obese, female university students were assigned to one of four groups based on median split scores on measures of dietary restraint and state-anxiety: low-restraint/low-anxiety (n=7), low-restraint/high-anxiety (n=7), high-restraint/low-anxiety ...

RATIONALE: Stimulation of ventral tegmental area (VTA) muscarinic acetylcholine receptors (mAChRs) is implicated in feeding. OBJECTIVE: To investigate the effects of mAChR blockade in the VTA on food-related learning. METHODS: In experiment 1, rats (N=12) were placed in chambers containing food and received microinjections of 0 or 5 microg/0.5 microl ...

In the field, Atlantic cod face seasonal changes in food availability that in turn lead to changes in condition. To examine the physiological consequences of these changes in condition, we measured routine metabolic rate (RMR) to estimate standard metabolic rate (SMR), active metabolic rate (AMR), aerobic scope, critical swimming speed ...

Resistance to interference was examined in rats that received a complex negative patterning discrimination in which XA and XB were followed by food reinforcement and XAB was not Retention of the discrimination was evident after separate reinforcement of both A and B (Experiment 3), but not after reinforcement of either ...

Pigeons responded on fixed-interval and fixed-ratio food schedules during sessions of extended duration. Pause lengths from the beginning of the session, when the subjects were hungry, resembled those found in open economies, whereas pause lengths from the end of the sessions, when the subjects were close to satiation, resembled those ...

Rats acquired aversions to food pellets when a previously trained signal for that food was paired with a toxin, but only after minimal signal-food training. After extensive signal-food training, signal-toxin pairings had no effect on food consumption even after manipulations that enhanced the associability of the signal. By contrast, conditioned ...

Fluvoxamine, a serotonin reuptake blocker, was previously shown to decrease ethanol-maintained behavior at doses lower than those needed to decrease food-maintained behavior. While these effects could have been due to different response rates and histories of the two groups being compared, a subsequent study found differential effects using a within-subjects ...

The reinforcing value of food, measured by how hard someone is willing to work to obtain food, is influenced by food palatability, food deprivation and food variety, and may be a more powerful determinant of food intake than hedonics or liking. The reinforcing value of food is mediated in part ...

Smoking-related environmental stimuli have been implicated as an important factor in triggering relapse in abstinent tobacco smokers, and recent evidence indicates that drug-associated stimuli can reinstate nicotine-seeking in rats. However, there is little investigation on the factors that contribute to the latter effect. This study examined whether a nicotine-associated visual ...

Six male albino Wistar rats were placed in running wheels and exposed to a fixed interval 30-s schedule that produced either a drop of 15% sucrose solution or the opportunity to run for 15s as reinforcing consequences for lever pressing. Each reinforcer type was signaled by a different stimulus. To ...

Herrnstein's hyperbola describes the relation between response rate and reinforcer rate on variable-interval (VI) schedules. According to Herrnstein's (1970) interpretation, the parameter r(e) represents the reinforcer rate extraneous to the alternative to which the equation is fitted (the target alternative). The hyperbola is based on an assumption that extraneous reinforcer ...

The cannabinoid receptor agonists delta9-tetrahydrocannabinol (delta9-THC) and HU-210 were compared in terms of their effects on: (1) progressive ratio (PR) responding for food, and (2) free food intake. In the first experiment, food-deprived Wistar rats were trained on a time-constrained (60 min) PR-5 schedule for food reinforcement, in which the ...

BACKGROUND: Establishment of early oral nutrition after surgery is associated with a decrease in morbidity and mortality. The following studies were undertaken to determine how surgery influences food-reinforced behavior in rats and to determine the relevance of afferent input from the incision site on this behavior. METHODS: Rats were trained ...

Studies on Sprague-Dawley rats used intracerebral dialysis and high-performance liquid chromatography to identify sources of glutamate release into the intercellular space of the nucleus accumbens during forced correction of food-related behavior, i.e., on presentation to the feeding rat of a conditioned signal previously combined with a pain stimulus or on ...

We examined the ability of M. croceipes to learn, detect, and respond to 2,4-DNT, which is a volatile discriminator of trinitrotoluene (TNT). The percentage of conditioned wasps to detect and respond to the various concentrations of 2,4-DNT for > or = 15 sec was measured. Significantly more of the conditioned ...

Previous studies have demonstrated that consumption of a low-valued food substance may decrease if access to a high-valued substance will soon be available (negative anticipatory contrast). Research has also demonstrated that responding for a low-valued reinforcer may increase if responding for a high-valued reinforcer will soon be possible (positive induction). ...

We evaluated the effects of escape extinction with and without a high-probability (high-p) instructional sequence on food acceptance and inappropriate behavior for children diagnosed with feeding problems. The high-p sequence consisted of three presentations of a response that was similar topographically (i.e., presentations of an empty nuk, liquid on a ...

Recent studies indicate that GABAergic ligands modulate abuse-related effects of cocaine. The goal of this study was to evaluate the effects of a mechanistically diverse group of GABAergic ligands on the discriminative stimulus and reinforcing effects of cocaine in rats. One group of rats was trained to discriminate 5.6 mg/kg ...

Drugs that indirectly alter dopaminergic systems may alter the reinforcing effects of cocaine. The inhibitory neurotransmitter gamma-aminobutyric acid (GABA) has extensive neural connections in mesolimbic regions that appear to modulate dopamine. The current study evaluated the effects of GABA(B) receptor agonists baclofen and CGP44532, the benzodiazepine agonist alprazolam, and the ...

The results of a recent study have provided direct support for the suggestion that conditional learning in rats is best characterized by a 3-layer connectionist network (M. J. Allman, J. Ward-Robinson, & R. C. Honey, 2004). In the 2 experiments reported here, rats were used to investigate the nature of ...

This experiment examined the effects of reinforcement probability on resistance to change of remembering and response rate. Pigeons responded on a two-component multiple schedule in which completion of a variable-interval 20-s schedule produced delayed matching-to-sample trials in both components. Each session included four delays (0.1 s, 2 s, 4 s, ...

Developmental psychologists have described imitation as a process that suggests perspective-taking abilities. However, imitative behavior has been found in animals, which are generally not considered capable of taking the perspective of another. Previous studies with birds have demonstrated the imitation of a single response (sometimes referred to as action-level imitation). ...

A questionnaire was administered to 848 participants (76% runners, 24% walkers) at the conclusion of the 14 km City to Surf community run in order to investigate their experience of exercise-related transient abdominal pain (ETAP). Twenty-seven percent of respondents reported experiencing ETAP during the event, with the condition reported more ...

The role of the prefrontal cortex was studied in an active selection situation in which dogs had to choose one of two feeders, with changes in the quality and probability of the reinforcement provided in one of the feeders. The study was performed in two stages. Before surgery, animals were ...

Three experiments conducted on male C57BL/6 (B6) mice examined the effects of subcutaneous injections of the GABA uptake inhibitor, tiagabine, on appetitive (lever responding) and consummatory behavior (fountain contacts) of food restricted B6 mice for 12% ethanol and water rewards (Exp-1), and for food reward (Exp-2) delivered on a fixed ...

The procedures for classical and operant conditioning, and for many timing procedures, involve the delivery of reinforcers that may be related to the time of previous reinforcers and responses, and to the time of onsets and terminations of stimuli. The behavior resulting from such procedures can be described as bouts ...

In Experiment 1 with rats, a left lever press led to a 5-s delay and then a possible reinforcer. A right lever press led to an adjusting delay and then a certain reinforcer. This delay was adjusted over trials to estimate an indifference point, or a delay at which the ...

Humans routinely complete partly occluded objects to recognize the whole objects. However, a number of studies using geometrical figures and even conspecific images have shown that pigeons fail to do so. In the present study, we tested whether pigeons complete partially occluded objects in a situation simulating a natural feeding ...

RATIONALE: Punishment is widely used in an effort to control drug-taking behavior; however, only a few preclinical studies have investigated the effects of punishment on drug self-administration. Such studies may contribute to more rational use of punishment to control drug use. OBJECTIVES: To evaluate the effects of punishment on choice ...

Three experiments examined the mechanisms by which downward shifts in reinforcer value influence learning in appetitive unblocking procedures. The downward shift was accomplished by omitting the 2nd of a 2-reinforcer sequence (food-food or food-sucrose). Performance of normal rats was compared with that of rats with lesions of the central nucleus ...

Three experiments with pigeons explored the constancy of reinforcer omission during extinction conjectured by rate estimation theory. Experiment 1 arranged 3-component multiple variable-interval (VI) schedules with a mixture of food and extinction trials within each session. Reinforcers omitted to an extinction criterion increased with food-trial reinforcer rate. Experiment 2 arranged ...

Browse species undergo seasonal changes in nutritional value and secondary plant compound concentrations. The capacity of herbivores to monitor such change through postingestive effects and to modify their food choice appropriately was investigated. Twenty-four goats were offered a different conifer species on four successive learning days per 7-d period for ...

Two experiments were conducted to investigate punishment via response-contingent removal of conditioned token reinforcers (response cost) with pigeons. In Experiment 1, key pecking was maintained on a two-component multiple second-order schedule of token delivery, with light emitting diodes (LEDs) serving as token reinforcers. In both components, responding produced tokens according ...

The behavioral economic concept of unit price predicts that consumption and response output (labor supply) are determined by the unit price at which a good is available regardless of the value of the cost and benefit components of the unit price ratio. Experiment 1 assessed 4 pigeons' consumption and response ...

Effects of autoshaping procedures (Paired versus Random) and sipper fluid [chlordiazepoxide (CDP) versus water] on sipper-directed drinking were evaluated in 32 male Long-Evans rats maintained with free access to food and water. For the Paired/CDP group (n = 16), autoshaping procedures consisted of the presentation of the CDP sipper conditioned ...

We examined how a 50% Pavlovian partial reinforcement (PRF) schedule, versus a 100% continuous reinforcement (CRF) schedule, altered the asymptotic amount and distribution of focal and general search behavior in rats during 48-sec trials with and without a four-segment interfood clock (S1-S2-S3-S4-US). Under CRF, but not PRF, average asymptotic focal ...

Some individuals who engage in self-injurious behavior (SIB) also exhibit self-restraint. In the present study, a series of three functional analyses were conducted to determine the variables that maintained a participant's SIB, one without restraint items available, one with a preferred and effective form of self-restraint (an airplane pillow) available ...

We evaluated the effects of multiple treatment procedures, including simultaneous presentation of preferred foods, on the packing behavior of a 9-year-old girl with autism. A reversal design was used to assess the effects of differential reinforcement with response cost alone and with simultaneous presentation. In addition, simultaneous presentation was assessed ...

We examined the use of noncontingent reinforcement to decrease self-injury and increase bite acceptance in a child who exhibited food refusal. First, a brief functional analysis suggested that self-injury was maintained by escape from food presentation. Next, we evaluated an intervention that involved noncontingent access to a video during feeding ...

Experiments with pigeons and rats on concurrent-chains schedules examined a paradoxical effect reported by R. A. Preston and E. Fantino (1991). One schedule in the concurrent chain had a variable-interval (VI) 60-s initial link, and its terminal link was a 10-s delay to food. The other schedule had an initial ...

The primate amygdala is implicated in the control of behavioral responses to foods and in stimulus-reinforcement learning, but only its taste representation of oral stimuli has been investigated previously. Of 1416 macaque amygdala neurons recorded, 44 (3.1%) responded to oral stimuli. Of the 44 orally responsive neurons, 17 (39%) represent ...

RATIONALE: The metabotropic glutamate (mGlu5) receptor subtype 5 antagonist MPEP attenuates self-administration of numerous drugs of abuse. OBJECTIVES: The purpose of the present study was to explore whether MPEP-induced decreases in nicotine and cocaine self-administration reflect attenuation of the reinforcing and incentive motivational effects of nicotine and cocaine. The effects ...

The present study evaluated the effects of 8-carboxamidocyclazocine (8-CAC), a novel mixed-action kappa/mu agonist with a long duration of action, on food- and cocaine-maintained responding in rhesus monkeys to assess the potential utility of 8-CAC as a medication for the treatment of cocaine dependence. The effects of acute and chronic ...

The traditional method of measuring the relative reinforcing value of food provides subjects a choice of food and non-food alternatives, and defines the relative reinforcing value of food based on the allocation of responses for the two alternatives as the schedules of reinforcement for the alternatives change. Greater allocation of ...

Food-reinforced conditioned activity and instrumental responding were measured in rats after 50 weeks of continuous access to a cocaine-saccharin solution in their home cages. The elevation of conditioned activity produced by acute access to the cocaine-saccharin solution in the home cage during testing was abolished by long-term preexposure to the ...

Homeostasis, an organisms' tendency to maintain a healthy balance of the physiological state of the body, is necessary for survival. Hunger induces a motivational state to consume food. Recently, pain has been referred to as a homeostatic emotion similar to hunger or thirst in that animals are motivated to respond ...