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Results 501 - 550 of 629
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De Vleeschouwer K - - 1995
The effect of posture on hand preferences was examined in an experiment with 5 bonobos (Pan paniscus). To obtain a food reward, the animals had to adopt 1 out of 7 different postures. These postures represented an increasing problem to the maintenance of body equilibrium. It was expected that an ...
Comer S D - - 1995
Studies have shown that both food deprivation and response cost have important influences on the magnitude of self-administration of a wide variety of psychoactive drugs. In an attempt to extend these findings to the smoked route of drug self-administration, the effects of food allotment and fixed-ratio (FR) value were evaluated ...
Aou S - - 1994
Although the dopamine (DA) system has been shown to regulate food intake, the function of the DA receptor subtypes on behavior still remains to be elucidated. In the present study, we examined the effect of B-HT 920, a selective agonist of DA D2 receptors that preferentially affect presynaptic autoreceptors, on ...
Roney L S - - 1993
Squirrel monkeys (Saimiri sciureus) and cotton-top tamarins (Saguinus oedipus) made unimanual food reaches from either a horizontal, quadrupedal posture or a vertical, clinging posture. No population-level handedness occurred in either species. However, in both species, directional lateral preferences weakly expressed for reaching from the stable quadrupedal posture were intensified in ...
Champoux M - - 1993
Laboratory-born, group-housed, ovariectomized adult female squirrel monkeys (Saimiri sciureus) were exposed to feeding conditions in which the availability and accessibility of food were altered. Both high- and variable-demand feeding conditions were utilized. The variable-demand condition required alternating periods of high effort (120% of normal daily intake presented) and low effort ...
Hopkins W D - - 1993
Behavioral laterality was studied in a captive group of 11 bonobos (Pan paniscus). In an observational method a significant left lateral bias in carrying and a right lateral bias in leading limb were found. Direction of lateral bias in carrying and leading limb was enhanced when subjects maintained a bipedal ...
Corwin R L - - 1993
The present report describes a new procedure for assessing anorectic specificity. Two rhesus monkeys (Macaca mulatta) surgically prepared with indwelling intragastric catheters were trained in a discrete trial choice paradigm to respond for either food or visual access to a room containing other monkeys. Our hypothesis was that a specific ...
Schreihofer D A - - 1993
Short periods of fasting (1-2 days) significantly suppress the frequency of pulsatile LH secretion in adult male rhesus monkeys. Resumption of food intake (i.e. refeeding) after fasting rapidly restores pulsatile LH secretion. We hypothesized that the resumption of LH secretion after refeeding results from the metabolic consequences of food intake ...
Demaria-Pesce V H - - 1993
Previous experiments performed with mammals during spaceflight suggest that microgravity may affect the circadian timekeeping system. However, this system could also be influenced by other factors related to the spaceflight environment, such as the animal compartment. The Rhesus project is a joint program of C.N.E.S. and N.A.S.A in which investigators ...
Cherpas C - - 1993
Michael (this issue) defines an establishing operation (EO), such as food deprivation, as (a) altering the effectiveness of reinforcement as well as (b) evoking behavior. Although this dual role for EOs is compelling, it is possible that such operations have only evocative effects (i.e., function only in the form of ...
Yoshida M - - 1993
The effect of chronic administration of a probable endogenous dopaminergic neurotoxin, tetrahydroisoquinoline, has been examined on squirrel monkeys. Chronically administered TIQ produced motor symptoms similar to parkinsonism in squirrel monkeys even 7 days after discontinuation of TIQ and the symptoms were alleviated remarkably by L-DOPA treatment. Biochemical analysis of the ...
Hauser M D - - 1992
From a functional perspective, deception can evolve in animal populations but should be constrained by the costs associated with detection. It then follows that withholding information should be more prevalent as a form of deception than active falsification of information because of the relative difficulties associated with detecting cheaters. Empirical ...
Nader M.A. - - 1992
The present experiment was designed to examine the effects of the conditions of food availability on choice between cocaine and food in rhesus monkeys. Monkeys (n = 3), maintained at approximately 90% of their free-feeding weights, were trained in a discrete-trials choice procedure and allowed to choose between intravenous injections ...
Bard K A - - 1992
The goal of this study was to describe the ontogeny of the manipulation of an animate object (i.e., the mother) by young free-ranging orangutans within the context of food sharing. The food-sharing context is an important one in the development of object manipulation skills and social communication. 5 orangutans, ranging ...
Sinnott J M - - 1992
Frequency (delta F) and intensity (delta I) difference limens were directly compared in Mongolian gerbils (Meriones unguiculatus), Old World African Monkeys (Cercopithecus mitis, Cercocebus albigena), and humans. Methods employed a repeating background AX discrimination procedure, and positive (food) reinforcement for animals. For delta I, there were small quantitative differences between ...
Povinelli D J - - 1991
The ability of 4 rhesus monkeys (Macaca mulatta) to understand the causal connection between seeing and knowing was investigated. The subjects were tested to determine if they could discriminate between information provided by experimenters who randomly alternated between roles of guesser and knower. In a series of tests, the knower ...
Tamura R - - 1991
To investigate the role of the hippocampal formation (HF) in feeding behavior, single neuron activity in the monkey HF was recorded during performance of an operant task that included food/nonfood discrimination, drinking, and active avoidance. Of 837 neurons recorded in the HF, 155 responded to the sight of one or ...
Washburn D A - - 1991
Two rhesus monkeys (Macaca mulatta) learned that the arabic numerals 0 through 9 represented corresponding quantities of food pellets. By manipulating a joystick, the monkeys were able to make a selection of paired numerals presented on a computer screen. Although the monkeys received a corresponding number of pellets even if ...
Hannah J - - 1990
To investigate the role of plasma insulin on food intake, we have examined the effect of naturally occurring chronic hyperinsulinemia on the feeding behavior of male rhesus monkeys. Two groups of monkeys, a group with normal fasting insulin concentrations (52.4 +/- 2.2 microU/ml) (mean +/- SE) and a hyperinsulinemic group ...
Povinelli D J - - 1990
The visual perspective-taking ability of 4 chimpanzees (Pan troglodytes) was investigated. The subjects chose between information about the location of hidden food provided by 2 experimenters who randomly alternated between two roles (the guesser and the knower). The knower baited 1 of 4 obscured cups so that the subjects could ...
Hayes S L - - 1990
Capuchin monkeys often employ complex manipulative skills while recovering food items. Five captive Cebus capucinus were presented with two identical feeders that required the monkeys to lift up flaps, search through hay, and perform coordinated hand movements in order to obtain food items. The intent of this study was not ...
Welsh D K - - 1990
Lithium lengthens the period of free-running circadian rhythms in a variety of species, but this effect has not been demonstrated unequivocally in primates. Because of the possible link between lithium's action on the circadian clock and its therapeutic action in human mood disorders, we tested the ability of lithium to ...
Line S W - - 1990
Environmental enrichment devices are a potential way to enhance psychological well-being in laboratory animals. The effects of such devices need to be systematically evaluated before they are recommended for widespread use. The purpose of this research was to monitor the behavioural and physiological responses of adult female rhesus macaques to ...
Wissler R W - - 1990
For at least 60 years, spotty and poorly documented evidence has suggested that atherosclerotic disease in humans might be reversible. Little direct evidence was available until researchers demonstrated that rather advanced atherosclerotic lesions in experimental animals could show marked improvement after blood-lipid-reducing regimens that were often combined with other measures, ...
Lawes M J - - 1990
The samango monkey occurs at the southern limit of the range of Cercopithecus mitis. Greater climatic seasonality at this latitude results in more predictable fruiting patterns. In addition, there are no diurnal sympatric primate frugivores. Under these conditions, the diet and feeding strategies of samango monkeys would be expected to ...
Chapman C A - - 1990
The foraging strategies and association patterns of 3 species of primates (Ateles geoffroyi, Alouatta palliata, Cebus capucinus) were studied over a 5-year period. The objective of the study was to provide a quantitative test of the hypothesis that the size, density and distribution of food resources influence the size of ...
Boesch C - - 1990
Reported incidences of tool use and tool making for three wild chimpanzee populations increase from Mahale (12 and 3 types of use and making, respectively), Gombe (16 and 3) to Taï (19 and 6). Sticks are commonly used and prepared at all three sites. However, Taï chimpanzees seem to perform ...
Feistner A T - - 1990
Food-sharing behaviour was observed in 9 captive families of cotton-top tamarins (range 4-14 individuals per group), during meals of fresh fruit. Food was transferred to infants by their parents and older sibs in response to begging, and was also offered to them without prior solicitation. Older, mature, reproductively suppressed individuals ...
Evans K R KR University of Toronto, Department of Psychology, - - 1990
The present study examined the possibility that the increased feeding found following central and peripheral administrations of low doses of d-amphetamine (AMP) and morphine (MOR) may involve central reward mechanisms. In order to examine this possibility, the effects of these drugs on food selection and intake of foods that varied ...
Katz N L - - 1989
The present study examined the effect of structural analogs of clonidine on feeding in both rabbits and monkeys. In rabbits, lofexidine and tizanidine either did not influence or decreased food intake in contrast to clonidine, which stimulated food intake. Lofexidine elicited easily observed decreases in motor behavior with several of ...
Evans S M - - 1989
Pigeons were trained to discriminate i.m. administered d-amphetamine (AMPH) or pentobarbital (PB) from saline with responding maintained under a fixed-ratio 30 schedule of food delivery. Rhesus monkeys were trained to discriminate intragastrically administered AMPH or PB from saline using a signaled shock-avoidance trial procedure. In AMPH-trained pigeons the histamine H1-antagonists ...
Milliken G W - - 1989
Evaluated a free-ranging matriline of 13 ring-tailed lemurs (Lemur catta) from videotaped records for lateralized hand use with 2 tasks and 4 measures: food reaching, feeding posture, duration of food holding, and manipulation of food between mouth and hand while eating. Binomial z scores determined 7 lemurs to be left ...
Binienda Z - - 1989
We studied the hormonal responses in four pregnant rhesus monkeys between 112 and 149 days gestation. After 2 days, during which the monkeys were fed ad libitum, their food was withdrawn at 1500 h for 48 h while allowing free access to water. The food then was returned, and the ...
Kemnitz J W - - 1989
The influences of ovarian hormones on food intake, taste preferences, and glucoregulation were examined in intact and ovariectomized rhesus monkeys. Intake of intact monkeys was lowest in the preovulatory stage of the cycle, when estrogen levels are elevated, and exogenous estradiol transiently suppressed food intake of ovariectomized monkeys in a ...
Marriott B M - - 1989
The food ingestion patterns of the rhesus monkeys (Macaca mulatta) of Group L on Cayo Santiago were quantitatively recorded during two months which coincided with the annual breeding season. Three methods of sampling were used concurrently: interval scan sampling, group location mapping and focal animal observation. These data generated time ...
Evans M A - - 1989
A field project was conducted to remove an introduced population of rhesus macaques (Macaca mulatta) from Desecheo Island National Wildlife Refuge, Puerto Rico. A group of 57 monkeys from Cayo Santiago was released on Desecheo Island in 1966 to study processes of adaptation. Observations in 1969 and 1970 implicated the ...
Boysen S T - - 1989
A chimpanzee (Pan troglodytes), trained to count foods and objects by using Arabic numbers, demonstrated the ability to sum arrays of 0-4 food items placed in 2 of 3 possible sites. To address representational use of numbers, we next baited sites with Arabic numbers as stimuli. In both cases performance ...
Binienda Z - - 1989
Pregnant rhesus monkeys were studied between 109 and 149 days of gestation. Food withdrawal for 48 hours (with free access to water) was accompanied by a decrease in maternal whole blood glucose concentration and an increased maternal arterial plasma 13,14-dihydro-15-keto-prostaglandin F2 alpha concentration. On successive nights of the 48-hour period ...
Adamson R H - - 1989
Several compounds were evaluated in nonhuman primates for their potential to induce neoplasms, especially hepatocellular carcinoma (HCC). The compounds can be classified into three groups: food contaminants, model rodent carcinogens, and nitrosamines. All three compounds in the food contaminants group, namely, aflatoxin B1, sterigmatocystin, and methylazoxymethanol acetate, induced HCC. None ...
Fonberg E - - 1988
Dominance is a complex phenomenon mediated by different mechanisms. Various motivations and their mutual correlations determine the tendency to dominate. A subject that is dominant in every situation (i.e., absolutely dominant) is rather an exceptional case. Dominance may be limited to particular situations and exhibited only with some definite partners. ...
Clifton P G - - 1988
Chicks trained to take a food reward at the end of a runway can be distracted by changes in the appearance of either the food dish towards which they are running or of the walls of the runway remote from the food dish. Testosterone (administered as a long lasting ester ...
Sunderland G - - 1988
The taste preferences of adult male squirrel monkeys and bonnet macaques for Polycose, maltose, and sucrose solutions were compared in 24 hr/day solution vs. water tests. Solution concentrations of 0.01 M, 0.05 M, 0.10 M, and 0.20 (Polycose) or 0.50 M (maltose and sucrose) were tested. The squirrel monkeys displayed ...
Hernandez L L Department of Psychology, Princeton University, New Jersey - - 1988
Dopamine was measured by microdialysis in the nucleus accumbens of freely moving rats while they experienced rewarding food, brain stimulation and drugs. Extracellular dopamine increased 37% when the animals pressed a lever for food reward. Electrical stimulation of a lateral hypothalamic feeding-reward (self-stimulation) site caused a similar increase in dopamine, ...
Chamberlain B - - 1987
Social groups of vervet monkeys (Cercopithecus aethiops) were given amino acid mixtures that were tryptophan-free (T-), nutritionally balanced (B), or contained excess tryptophan (T+). The T- mixture caused a marked decrease in plasma tryptophan and the T+ mixture a large increase. Behavioral observations were made on the animals after administration ...
Sinnott J M - - 1987
Humans and monkeys were compared in their differential sensitivity to various acoustic cues underlying voicing contrasts specified by voice-onset time (VOT) in utterance-initial stop consonants. A low-uncertainty repeating standard AX procedure and positive-reinforcement operant conditioning techniques were used to measure difference limens (DLs) along a VOT continuum from--70 ms (prevoiced/ba/) ...
Wilpizeski C R - - 1987
It has been suggested by numerous researchers that the development of conditioned food aversion (CFA) in experimental animals represents the presence of a subjective state of illness. Squirrel monkeys with proven susceptibility to rotation-induced vomiting were given surgical bilateral labyrinthectomies, a procedure known to abolish signs and symptoms of motion ...
Sinnott J M - - 1987
Auditory duration DLs at 2.0 kHz were measured in Old World monkeys (Macaca, Cercopithecus) and humans using a go, no-go repeating standard AX procedure and positive reinforcement operant conditioning techniques. For a 200-ms standard, monkey DLs were 45-125 ms, compared to 15-27 ms for humans. Weber fractions (delta T/T) for ...
Carroll M E - - 1987
Two experiments addressed the effects of food satiation and deprivation on oral self-administration of two concurrently available phencyclidine concentrations. In the first experiment, 8 rhesus monkeys self-administered either of two concentrations of phencyclidine ("PCP, angel dust") and water under concurrent fixed-ratio 16 schedules. One concentration was always held constant (0.25 ...
Rumbaugh D M - - 1987
In this research, we asked whether 2 chimpanzee (Pan troglodytes) subjects could reliably sum across pairs of quantities to select the greater total. Subjects were allowed to choose between two trays of chocolates. Each tray contained two food wells. To select the tray containing the greater number of chocolates, it ...
Corwin R L - - 1987
The effects of the anorectics benzphetamine, chlorphentermine, clortermine, mazindol, phendimetrazine, and phenmetrazine on food intake were compared to the effects of d-amphetamine in rhesus monkeys given daily access to food pellets. The ability of these compounds to maintain intravenous self-administration under a fixed-ratio 10 schedule was also determined in rhesus ...
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