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Results 301 - 350 of 1343
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Mazur James E - - 2005
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 ...
Kadohisa M - - 2005
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 ...
Paterson Neil E NE Department of Neuropharmacology, CVN-7, The Scripps Research Institute, La Jolla, CA 92037, - - 2005
The metabotropic glutamate (mGlu5) receptor subtype 5 antagonist MPEP attenuates self-administration of numerous drugs of abuse. 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 of MPEP ...
Stevenson Glenn W GW Alcohol and Drug Abuse Research Center, McLean Hospital-Harvard Medical School, 115 Mill Street, Belmont, MA 02478, - - 2004
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 ...
Goldfield Gary S - - 2005
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 ...
Miles Felicity J FJ Department of Experimental Psychology, University of Cambridge, Cambridge, United - - 2004
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 ...
LaGraize Stacey C - - 2004
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 ...
Friedrich Andrea M AM Department of Psychology, University of Kentucky, Lexington, KY 40506-0044, - - 2004
Although animals typically prefer to exert less effort rather than more effort to obtain food, the present research shows that requiring greater effort to obtain food at a particular location appears to increase the value of that location. In Experiment 1, pigeons' initial preference for one feeder was significantly reduced ...
Thornton-Jones Zoë D - - 2005
RATIONALE: The CB1 receptor antagonist SR141716A reduces food intake in rats. This effect is likely to depend on modulation of reward related processes. OBJECTIVE: To investigate the effects of SR141716A on responding for food under a second order instrumental task in which responding and consumption of food can be separated, ...
Onuki Yasuhiro - - 2005
Food-carrying behavior in foraging rats has been assumed to have an advantage to avoid risks by shortening time spent outside their nests. However, there is no experimental evidence for this. In the present study, food-carrying behavior for four sizes of food pellets (45, 100, 200, and 1000 mg) was measured ...
LeSage Mark G - - 2004
The effects of two anorectic drugs, dexfenfluramine and phentermine, on food intake under different food-access conditions were examined. Experiment 1 compared the effects of these drugs on food intake under a progressive-ratio (PR) schedule and free-access conditions. Dexfenfluramine decreased food intake under both conditions, but the doses required to decrease ...
Kearns David N - - 2004
A series of experiments was performed to determine whether sign-tracking would occur in rats with intravenous (i.v.) cocaine as the unconditioned stimulus. In Experiment 1, a retractable lever paired with food produced strong sign-tracking, but a lever paired with one of three doses of i.v. cocaine did not elicit any ...
López-Crespo Ginesa - - 2004
Food-deprived rats that receive intermittent delivery of small amounts of food develop excessive drinking--specifically, schedule-induced polydipsia (SIP). A main characteristic of SIP is its occurrence at the beginning of interfood intervals. The purpose of this study was to demonstrate that SIP can be developed toward the end of interfood intervals, ...
Hironaka Naoyuki - - 2004
Dopamine (DA) plays roles in circuits that are important for brain reward and in striatal brain regions that are important for certain types of habit learning. These processes in wildtype, heterozygous, and homozygous dopamine transporter knockout (DAT-KO) mice, which were mildly food deprived and allowed to make nose-poke responses for ...
Foltin Richard W - - 2004
The effects of pharmacological manipulations on responding under extinction conditions were determined in baboons using a schedule of reinforcement that modeled food acquisition and food consumption. Responding during the initial acquisition component was reinforced by stimuli paired with food, while responding during the latter consumption component was reinforced with food. ...
Markou Athina - - 2004
Previous work indicated a role for GABA and glutamate in the reinforcing effects of drugs of abuse. The present studies assessed the effects of GABAergic and glutamatergic manipulations on the reinforcing effects of nicotine as assessed by intravenous nicotine self-administration. Male Wistar rats were allowed to self-administer either of two ...
Dias C C Laboratoire de Neuropsychobiologie des Désadaptations, UMR CRNS 5541, Université Victor Ségalen, Bordeaux 2, 146, rue Leo Saignat, BP 31, 33076 Bordeaux Cedex, France. - - 2004
The dopaminergic pathways are involved in natural and drug reward related processes. To compare the respective involvement of the dopaminergic receptors D1, D2 and D3 in natural-seeking versus drug-seeking behaviour and evaluate any concomitant expression of locomotor sensitisation. In separate experiments, male Wistar rats were trained to self-administer cocaine (0.25 ...
Orduña Vladimir - - 2004
Four pigeons and three ringneck doves responded on an operant simulation of natural foraging. After satisfying a schedule of reinforcement associated with search time, subjects could "accept" or "reject" another schedule of reinforcement associated with handling time. Two schedules of reinforcement were available, a variable interval, and a fixed interval ...
Murphy Robin A - - 2004
The serial order in which events occur can be a signal for different outcomes and therefore might be a determinant of how an animal should respond. In this report, we propose a novel design for studying serial order learning in Pavlovian conditioning. In both Experiments 1a and 1b, hungry rats ...
Odum Amy L - - 2004
Recent experiments suggest that the effects of drugs of abuse on the discrimination of the passage of time may differ for experimenter-imposed and subject-produced events. The current experiment examined this suggestion by determining the effects of morphine on the discrimination of interresponse times (IRTs). Pigeons pecked a center key on ...
Vervliet Bram - - 2004
In a human fear conditioning paradigm using the skin conductance response (SCR), participants were assigned to two groups. Following identical acquisition, group ABA (n = 16) was extinguished to a generalization stimulus (GS), whereas group AAB (n = 20) was extinguished to the conditioned stimulus (CS). At test, presenting the ...
Vanetsian G L - - 2004
The extent of correlation and the latency of evoked potentials to sound, recorded bilaterally in the frontal cortex and lateral hypothalamus of cats, were studied at different stages of the acquisition of an operant food-related reflex and during sudden transfer to 30% food reinforcement. High correlation coefficients between the evoked ...
Okten Zeynep - - 2004
Myosin VI is a molecular motor that can walk processively on actin filaments with a 36-nm step size. The walking mechanism of myosin VI is controversial because it takes very large steps without an apparent lever arm of required length. Therefore, myosin VI is argued to be the first exception ...
Epstein Leonard H - - 2004
BACKGROUND: Food reinforcement and dopaminergic activity may influence food consumption, but research on whether they interact has not been performed. OBJECTIVE: We assessed the effects of food reinforcement and the interaction of food reinforcement with the dopamine transporter (SLC6A3) genotype and the dopamine D(2) receptor (DRD(2)) genotype on energy consumption. ...
Haselgrove Mark M School of Psychology, Cardiff University, Wales, United Kingdom. - - 2004
In 4 experiments rats received appetitive Pavlovian conditioning followed by extinction. Food accompanied every trial with the conditioned stimulus (CS) for the continuously reinforced groups and only half of the trials for the partially reinforced groups. In contrast to previous experiments that have compared the effects of partial and continuous ...
Mazur James E - - 2004
In Experiment 1, pigeons responded on concurrent-chains schedules with equal variable-interval schedules as initial links and fixed delays to food as terminal links. One terminal-link delay was always three times as long as the other. As terminal-link delays increased, response percentages on the key with the shorter terminal link increased ...
Blaisdell Aaron P - - 2005
The integration of spatial maps in pigeons was investigated using a spatial analog to sensory preconditioning. The pigeons were tested in an open-field arena in which they had to locate hidden food among a 4x4 grid of gravel-filled cups. In phase 1, the pigeons were exposed to a consistent spatial ...
Zarcone Troy J - - 2004
Developments in the genetic manipulation of mice have intensified interest in the relation between genes, environment and learned behavior, which in turn has led to exploration of experimental procedures for assessing genetic influences on learning using methods such as response acquisition. The requirement for multiple experimental control groups in such ...
Igaki Takeharu - - 2004
Resistance to change has been studied in several species such as humans, rats, and pigeons. We conducted two experiments using goldfish as subjects to examine the generality of the findings on resistance to change in a phylogenetically more primitive species. In Experiment 1, five goldfish (Carassius auratus) were trained on ...
Shaw D - - 2004
Relatively little is known about the role of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in extinction of appetitively motivated tasks. The benzodiazepine (BZ) chlordiazepoxide (CDP) was administered during extinction and re-acquisition of lever pressing by mice following food reinforced discrete-trial fixed-ratio 5 (FR-5) training. Typical FR behaviour was established during ...
Epstein Leonard H - - 2004
Both the hedonic ratings and the reinforcing value of food have been considered to be determinants of food intake. The objective of this study was to compare the pleasurable ratings and the reinforcing value of food as determinants of energy intake. Seventy-four smokers were studied in food consumption and reinforcing ...
McSweeney Frances K - - 2004
Pigeons' keypecking was reinforced by food on baseline schedules of multiple variable interval (VI) x VI x and on contrast schedules of multiple VI x VI y. Deprivation of food was varied by maintaining subjects at 75%, 85%, and 95% (+/- 2%) of their free-feeding weights. Positive and negative behavioral ...
Lynch W J - - 2004
Cocaine addiction has been characterized by a shift from controlled to uncontrolled and compulsive drug use. Using novel self-administration procedures, we attempted to model this transitional phase and characterize the behavioral changes that underlie it. We chose to use food-reinforced responding across the light/dark cycle as an indicator of the ...
Weatherly Jeffrey N JN Department of Psychology, University of North Dakota, Grand Forks 58202-8380, USA. - - 2004
Rats' operant responding for sucrose rewards in the 1st half of a session can vary directly with the conditions of reward in the 2nd half. The authors investigated whether that induction effect represented an animal model of emotive states. Rats pressed a lever for either ethanol or sucrose rewards in ...
Smith James B - - 2004
Key pressing of rats was maintained under multiple and discrete-trial choice schedules with reinforcer units of 45 mg food pellets or 3.5 s dips of sucrose solution. Both smaller and larger fixed ratio (FR) schedules were associated with the same unit price in a manner, for example, that each of ...
Maccarone R - - 2004
We have compared the effect of two distinct Ih inhibitors on the temporal properties of the ERG response that, as previously shown, correlates well with the HCN activation in rods. The present results confirm the notion that cilobradine is more effective than zatebradine in inducing bradycardia. Importantly, the doses of ...
Foltin Richard W - - 2004
The purpose of this study was to determine how stimuli paired with food alters the effects of pharmacological and dietary manipulations on food intake. Responding of baboons was studied using a schedule of reinforcement that simulated food 'seeking' and food 'taking'. Under one condition, responding during the initial seeking component ...
Shull Richard L - - 2004
Rats obtained food pellets on a variable-interval schedule of reinforcement by nose poking a lighted key. After training to establish baseline performance (with the mean variable interval set at either 60, 120, or 240 s), the rats were given free access to food during the hour just before their daily ...
Belke Terry W - - 2004
As body weight increases, the excitatory strength of a stimulus signaling an opportunity to run should weaken to a greater degree than that of a stimulus signaling an opportunity to eat. To test this hypothesis, six male albino Wistar rats were placed in running wheels and exposed to a fixed ...
Saul'skaya N B - - 2004
Experiments on Sprague-Dawley rats using vital intracerebral dialysis and HPLC with electrochemical detection demonstrated that presentation of the animals with inedible imitation food or food containing a bitter flavor instead of the expected food reinforcement led to rapid increases in glutamate levels in the intercellular space of the nucleus accumbens. ...
Malone John C - - 2004
Pigeons accustomed to food reinforcement for responding in the presence of a 25-Hz flickering light were exposed to several sets of flicker-frequency stimuli arranged as increasing and decreasing series. In the first experiment, food was occasionally delivered for key pecks during 30-s periods of 25-Hz flicker appearing at the beginning, ...
Brody Stuart - - 2004
RATIONALE: Hypoglycemia leads to undernutrition of the brain. Favoring selective processing of food stimuli would be an adaptive cognitive strategy. However, hypoglycemia is known to impair several aspects of cognitive function, and it is unknown whether selective cognitive processing of food stimuli occurs during insulin-induced hypoglycemia. METHODS: In a single-blind ...
Harbig, Philipp
SUMMARY Drugs of abuse becomes increasingly present in today’s affluent society. Immoderate drug abuse has risen to a deadly serious problem in today’s youth. Animal research with operant conditioning approach is one way of fathoming this problem and can contribute to gaining a clearer understanding of drug addiction. In order ...
Reed Gregory K - - 2004
In the current investigation, we evaluated the relative effects of noncontingent reinforcement (NCR), escape extinction, and a combination of NCR and escape extinction as treatment for the feeding problems exhibited by 4 children. For each participant, consumption increased only when escape extinction was implemented, independent of whether NCR was present ...
Foster Theresa A - - 2004
Pigeons were exposed to multiple and concurrent second-order schedules of token reinforcement, with stimulus lights serving as token reinforcers. Tokens were produced and exchanged for food according to various fixed-ratio schedules, yielding equal and unequal unit prices (responses per unit food delivery). On one schedule (termed the standard schedule), the ...
Weatherly Jeffrey N - - 2004
In the present experiment, the authors investigated the idea that within-session changes in operant response rates occur because subjects sensitize and then habituate to the reinforcer. If that is true, then altering an aspect of the reinforcer within the session should alter the observed within-session responding. The authors tested that ...
Cerutti D T - - 2004
In the time-left experiment (J. Gibbon & R. M. Church, 1981), animals are said to compare an expectation of a fixed delay to food, for one choice, with a decreasing delay expectation for the other, mentally representing both upcoming time to food and the difference between current time and upcoming ...
Kelley Ann E AE Department of Psychiatry and Neuroscience Program, University of Wisconsin-Madison Medical School, 6001 Research Park Boulevard, Madison, WI 53719, USA. - - 2004
The nucleus accumbens is a brain region that participates in the control of behaviors related to natural reinforcers, such as ingestion, sexual behavior, incentive and instrumental learning, and that also plays a role in addictive processes. This paper comprises a review of work from our laboratory that focuses on two ...
Roeder Ryan K - - 2003
Synthetic hydroxyapatite (HA) whiskers have been utilized as a new, biocompatible reinforcement for orthopedic biomaterials. High-density polyethylene (HDPE) was reinforced with either the synthesized HA whiskers or a commercially available spherical HA powder using a novel powder processing technique that facilitated uniform dispersion of the reinforcements in the matrix prior ...
Epstein Leonard H - - 2003
Repeated presentation of food cues results in habituation in adults, as demonstrated by a decrement in salivary responding that is reversed by presenting a new food cue in adults. Food reinforced behavior in animals shows the same pattern of responding, with a decrease in responding to obtain the food, followed ...
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