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Results 401 - 450 of 1343
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Reneerkens Jeroen - - 2002
In this study, we tested the hypothesis that baseline corticosterone levels increase with a change from constant to variable feeding schedules. Captive red knots, Calidris canutus, were presented with food that was either available during the same time each day (constant) or starting at variable times during the day. Food ...
Witkin Jeffrey M - - 2002
RATIONALE: A host of factors that modulate the increases produced by benzodiazepines on responding suppressed by punishment have been described. Nonetheless, the necessary and sufficient conditions for the anxiolytic-like activity in this animal model have not been fully delineated. OBJECTIVES: The present experiments sought to determine the necessity of the ...
Tomie Arthur - - 2002
Pavlovian autoshaping conditioned responses (CRs) are complex sequences of conditioned stimulus (CS)-directed skeletal-motor responses that are elicited by CS objects predictive of food unconditioned stimulus (US). Autoshaping CRs are observed under conditions known to be conducive to elevations in plasma corticosterone levels, as, for example, in response to the eating ...
Myers Ernst Michelle - - 2002
Habituation to repeated food stimuli has been demonstrated in various response systems across animals and humans. Patterns of responding to obtain food demonstrate many empirical characteristics of habituation, and the purpose of the present study was to determine whether motivated responding for food in humans follows an habituation pattern. Thirty-five ...
Schwartz Bennett L - - 2002
Single-trial learning and long-term memory of "what" and "who" information were examined in an adult gorilla (Gorilla gorilla gorilla). We presented the gorilla with a to-be-remembered food item at the time of study. In Experiment 1, following a retention interval of either approximately 7 min or 24 h, the gorilla ...
Foltin Richard W - - 2002
Ingestive behavior consists of appetitive or foraging behavior, i.e., "acquisition," followed by consummatory behavior. Responding of six adult rhesus monkeys, living in three-chambered enclosures, was studied under an operant chain schedule that simulated commodity acquisition and commodity consumption. Responding during the initial acquisition component was reinforced by stimuli paired with ...
Derenne Adam - - 2002
Seven rats responding under fixed-ratio or variable-ratio schedules of food reinforcement had continuous access to a drinking tube inserted into the operant chamber. Under different conditions they could drink either tap water or one of two saccharin solutions. In a baseline condition, the drinking bottle was empty. Preratio pausing was ...
Nevin John A. - - 2002
The metaphor of behavioral momentum proposes that when ongoing operant behavior is disrupted, changes in response rate are directly related to a force-like aspect of the disruptor and inversely proportional to behavioral mass. Several data sets suggest that differential resistance to change between the components of a multiple schedule satisfies ...
Kirkpatrick Kimberly - - 2002
Packet theory is based on the assumption that the momentary probability of producing a bout or packet of responding is controlled by the conditional expected time function. Bouts of head entry responses of rats into a food cup appear to have the same characteristics across a range of conditions. The ...
Salamone J D - - 2002
RATIONALE: Dopamine is important for enabling organisms to overcome work-related response costs. One way of investigating this function has been with concurrent choice procedures using food reinforcement. In the present study, rats were given a choice between pressing a lever for preferred Bioserve pellets, or approaching and consuming a less-preferred ...
Crystal Jonathon D - - 2002
Rats searched for food that was contingent on time and place in an open field. One location was active at a time, the active location moved in a clockwise direction after each reward, and each location was repeated several times on each daily session. When a location was active, the ...
Grace Randolph C - - 2002
Experiment 1 compared the acquisition of initial- and terminal-link responding in concurrent chains. The terminal-link schedules were fixed interval (FI) 10 sec and FI 20 sec, but some presentations were analogous to no-food trials in the peak procedure, lasting 60 sec with no reinforcement delivery. Pigeons completed a series of ...
Baunez Christelle C Laboratoire de Neurobiologie Cellulaire et Fonctionnelle, Centre National de la Recherche Scientifique, 13402 Marseille cedex 20, France. - - 2002
Although inactivation of the subthalamic nucleus (STN) has beneficial effects on motor symptoms of parkinsonism, little is known of possible actions on nonmotor symptoms of cognition or mood. Here, we used several forms of converging evidence to show that STN lesions can enhance behavioral motivation. Thus, bilateral fiber-sparing lesions of ...
Zhou Liming - - 2002
Assessments were conducted to identify preferred foods for 9 adults with severe to profound mental retardation. Subsequently, the reinforcing effects of each participant's most highly preferred food were evaluated during sessions conducted before and after lunch. Results showed that 4 participants' response rates were higher during premeal sessions than during ...
Wright Carrie S - - 2002
We replicated and extended treatment procedures described by Lennox, Miltenberger, and Donnelly (1987) designed to reduce rapid eating. The participant was a 17-year-old girl with developmental disabilities who engaged in dangerously high rates of food ingestion. The procedure involved an adjusting differential-reinforcement-of-low-rate-responding (DRL) schedule, response blocking, and prompts. We evaluated ...
Sevin Bart M - - 2002
This study examined the effects of sequentially introducing treatment across multiple topographies of food refusal. Treatment with nonremoval of the spoon produced an increase in food acceptance and a decrease in disruption, but expulsion of food increased. When expulsion was treated, packing of food increased. Finally, when packing was treated, ...
Patel Meeta R - - 2002
Consumption of solids and liquids occurs as a chain of behaviors that may include accepting, swallowing, and retaining the food or drink. In the current investigation, we evaluated the relative effectiveness of differential reinforcement of the first behavior in the chain (acceptance) versus differential reinforcement for the terminal behavior in ...
Koetzner Lee - - 2002
For research and therapeutic purposes, a cocaine antagonist is an important drug development goal. The vesicular monoamine transport inhibitor tetrabenazine was tested for interaction with cocaine using food-reinforced responding in rhesus monkeys as an assay. Both tetrabenazine and cocaine suppressed food-maintained behavior individually. However, a low-dose tetrabenazine pretreatment did not ...
Pearce John M - - 2002
when A+ B+ training was conducted in the absence of CD+ trials. A further failure to observe abnormally strong responding during AB was found in Experiment 3 for which the training trials with A+ B+ CD+ were accompanied by trials in which C and D were separately paired with food. ...
Galbicka G - - 2001
The behavioral effects of a variety of advanced candidate anticonvulsants for organophosphate-induced seizures were evaluated under two rodent 'counting' models. Rats pressed the left of two levers a number of times (a 'run') before pressing the right lever. The targeted performance was a run of 12. The training contingency was ...
Pério A A Centre de Recherche Sanofi-Synthélabo, Montpellier, France. - - 2001
Cannabinoids increase food intake, via CB1 receptors. The CB1 antagonist, SR141716, has been reported to decrease palatable food consumption in both operant and non-operant procedures. Similarly, CB1 receptor blockade diminished responding for normal food pellets under a fixed-ratio 15 (FR-15) schedule of reinforcement. The present experiment investigated whether the control ...
Goddard Murray J. - - 2001
Context modulation of an unconditioned stimulus (US) signal value was examined in three groups of rats. In Group A+/B-, subjects received explicit training in which a single food pellet US was followed by three additional pellets after either a short delay (in Context A) or a long delay (in Context ...
Weatherly J N. - - 2001
Previous research has demonstrated that rats' rates of lever pressing for low-concentration liquid-sucrose reinforcers are increased when food-pellet, rather than sucrose, reinforcement will be upcoming in the same session (i.e. induction). The present experiments were designed to determine whether this induction was the product of 'anticipatory responses' for the upcoming ...
Kelly D M - - 2001
Pigeons were trained to search for hidden food in a rectangular environment designed to eliminate any external cues. Following training, the authors administered unreinforced test trials in which the geometric properties of the apparatus were manipulated. During tests that preserved the relative geometry but altered the absolute geometry of the ...
Foltin R W - - 2001
RATIONALE: Feeding consists of appetitive or foraging behavior followed by consummatory behavior. OBJECTIVES: To determine if pharmacological manipulations can differentially affect appetitive and consummatory aspects of food intake, and to compare these results to those obtained using naturalistic dietary manipulations. METHODS: Responding of baboons was studied using a schedule of ...
Rossnagel C S - - 2001
Four experiments in the brain scans paradigm (P. Lewicki, T. Hill, & I. Sasaki, 1989) investigated hidden covariation detection (HCD). In Experiment 1 HCD was found in an implicit- but not in an explicit-instruction group. In Experiment 2 HCD was impaired by nonholistic perception of stimuli but not by divided ...
Foster T A - - 2001
Pigeons' key pecks produced food under second-order schedules of token reinforcement, with light-emitting diodes serving as token reinforcers. In Experiment 1, tokens were earned according to a fixed-ratio 50 schedule and were exchanged for food according to either fixed-ratio or variable-ratio exchange schedules, with schedule type varied across conditions. In ...
Doughty A H - - 2001
A multiple chained schedule was used to compare the relative resistance to change of variable and fixed four-peck response sequences in pigeons. In one terminal link, a response sequence produced food only if it occurred infrequently relative to 15 other response sequences (vary). In the other terminal link, a single ...
Goddard M J - - 2001
Context modulation of unconditioned stimulus (US) signal value was examined in two experiments. In Experiment 1, rats showed significantly more magazine entries after a single food pellet US in Context A (in which three additional pellets shortly followed) than in Context B (in which the delivery of three additional pellets ...
Astley S L - - 2001
Three experiments examined superordinate categorization via stimulus equivalence training in pigeons. Experiment 1 established superordinate categories by association with a common number of food pellet reinforcers, plus it established generalization to novel photographic stimuli. Experiment 2 documented generalization of choice responding from stimuli signaling different numbers of food pellets to ...
Nevin J A - - 2001
Two experiments asked whether resistance to change depended on variable-ratio as opposed to variable-interval contingencies of reinforcement and the different response rates they establish. In Experiment 1, pigeons were trained on multiple random-ratio random-interval schedules with equated reinforcer rates. Baseline response rates were disrupted by intercomponent food, extinction, and prefeeding. ...
Ploog B O - - 2001
The effect of primary reinforcement on initial-link responding under concurrent-chains schedules with nondifferential terminal links was assessed in 12 pigeons. The iniitial and terminal links were variable-interval schedules (always the same for both alternatives). The positions (left or right key) of the initial-link stimuli (red or green) were randomized while ...
Levin L - - 2001
Excessive food selectivity typifies some children with developmental disabilities. We conducted functional analyses to determine the controlling variables for problem behavior that accompanied food selectivity and analyzed the role of establishing operations in ameliorating food selectivity. Specifically, we studied the differential effects on intervention efficacy of an individual's having or ...
Nowend K L - - 2001
Although interference with dopamine (DA) systems can suppress lever pressing for food reinforcement, it is not clear whether this effect occurs because of a general disruption of food motivation. One way of assessing this has been a choice procedure in which a rat responds on an fixed ratio 5 (FR5) ...
Honey R C - - 2001
In 2 experiments, when rats were placed in 1 pair of contexts, A and B, 2 relationships were in force (X --> food and Y --> no food), and when they were placed in another pair of contexts, C and D, the complementary relationships were operative (Y --> food and ...
Miklósi A - - 2001
When a zebrafish has to choose between two identical stimuli (e.g. a conditioned stimulus, CS, for food reward), it tends to respond to the one on its right. Errors are more numerous when reinforced for taking the one on the left rather than the one on the right. When trained ...
Lamb R J - - 2001
Serotonergic deficiencies have been associated with alcoholism, and increasing serotonin function has been reported to decrease ethanol consumption. In this study, we examined the effects of the selective serotonin reuptake inhibitor, fluvoxamine, upon ethanol self-administration in the rat, and as a test of specificity also examined the effects of fluvoxamine ...
Stojanovic M N - - 2001
We adapted in two steps a deoxyribonucleotide-based aptamer to signal the recognition of cocaine: an instability was engineered in one stem of a three-way junction that forms the cocaine-binding pocket and the resulting short stem was end labeled with a fluorophore and a quencher. In the absence of cocaine, two ...
Shull R L - - 2001
The rate of a reinforced response is conceptualized as a composite of engagement bouts (visits) and responding during visits. Part I of this paper describes a method for estimating the rate of visit initiations and the average number of responses per visit from log survivor plots: the proportion) of interresponse ...
Bonardi C - - 2001
Three experiments examined appetitive classical conditioning in rats with small electrolytic lesions of the dorsal hippocampus. In all the experiments, the reinforcer was food delivery and the conditioned response (CR) entry to the food tray; the three experiments differed in the nature of the conditioned stimulus (CS). When this was ...
Tsunematsu S - - 2001
Demand curves for food were compared under the effort- and time-cost conditions using response-initiated fixed-ratio (FR) and fixed-interval (FI) schedules. For the effort-cost conditions, two pigeons were exposed to FR 3, 30, 90, and 150 for six sessions each. The time equivalent of each ratio was a FI schedule, each ...
Dorrance B R - - 2001
The 2-action method was used to examine whether imitative learning in Japanese quail (Coturnix japonica) depends on the motivational state of the observer quail at the time of observation of the demonstrated behavior. Two groups of observers were fed before observation (satiated groups), whereas 2 other groups of observers were ...
Campbell U C - - 2001
RATIONALE: Ketoconazole, an inhibitor of corticosterone synthesis, has been reported to decrease the self-administration of low doses of cocaine and prevent stress-induced reinstatement of cocaine-reinforced behavior in rats. OBJECTIVES: The effects of ketoconazole were extended to the acquisition of i.v. cocaine self-administration during food restriction, a form of stress. Food ...
Maes J H - - 2001
This study assessed the effects of acute amphetamine and ketamine on the performance of rats in a serial negative patterning procedure. A 5 s auditory target stimulus and a 5 s visual feature cue were each followed by food, but the target stimulus was not followed by food if preceded ...
van Haaren F - - 2001
Small doses of pyridostigmine bromide (PB) affect the acquisition and maintenance of food-maintained behavior in laboratory animals. The present experiment was designed to investigate the effects of this drug on food motivation. Male and female rats were trained to respond on a progressive-ratio schedule of reinforcement and treated with different ...
Kahng S W - - 2001
We examined the use of a multicomponent treatment for food refusal exhibited by a 5-year-old boy who had been diagnosed with mild to moderate mental retardation. Treatment consisted of access to highly preferred tangible items, which were removed contingent on problem behavior or not accepting a bite, and differential reinforcement ...
Hagopian L P - - 2001
Although response blocking can decrease problem behavior, one potential adverse side effect is the induction of aggression. In the current study, we report on a young adult who engaged in high rates of pica maintained by automatic reinforcement. Blocking pica, however, led to aggression. When redirection to an alternative preferred ...
Murphy R A - - 2001
Two experiments investigated the relative validity effect with either 1 or 2 continuously reinforced cues in Wistar rats using appetitive Pavlovian and instrumental preparations. Discrimination training involved 3 compound cues containing a common element (1AX: 1BX: 2CX). In the first true-discrimination group (TD-1), CX was followed by food, but AX ...
Bornhausen M - - 2000
To clarify potential health risks of radio-frequency electromagnetic fields (EMFs) used in cellular telephone technology to the developing brain, Wistar rats were continuously exposed during pregnancy to a low-level (0.1 mW/cm(2)) 900 MHz, 217 Hz pulse modulated EMF that approximated the highest legal exposure of normal populations to the radiation ...
Donahoe J W - - 2000
Revaluation refers to phenomena in which the strength of an operant is altered by reinforcer-related manipulations that take place outside the conditioning situation in which the operant was selected. As an example, if lever pressing is acquired using food as a reinforcer and food is later paired with an aversive ...
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