Search Results
Results 451 - 500 of 637
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Sulkowski G M - - 2001
Animals, including pigeons, parrots, raccoons, ferrets, rats, New and Old World monkeys, and apes are capable of numerical computations. Much of the evidence for such capacities is based on the use of techniques that require training. Recently, however, several studies conducted under both laboratory and field conditions have employed methods ...
Wallis J D - - 2001
To gain insight into the nature and neural specificity of the relationship between simple problem solving, inhibitory control and prefrontal cortex, comparison of the effects of excitotoxic lesions of the orbitofrontal and lateral prefrontal cortex were examined on the performance of common marmosets on a detour reaching task. Monkeys were ...
Laska M - - 2001
I assessed the occurrence of food preferences in captive squirrel monkeys and pigtail macaques and analyzed whether their preferences correlate with nutrient composition. Using a two-alternative choice test, I repeatedly presented six Saimiri sciureus and six Macaca nemestrina with all possible binary combinations of 12 types of food that are ...
LaBar K S - - 2001
Functional magnetic resonance imaging (fMRI) was used to determine whether visual responses to food in the human amygdala and related corticolimbic structures would be selectively altered by changes in states of hunger. Participants viewed images of motivationally relevant (food) and motivationally irrelevant (tool) objects while undergoing fMRI in alternately hungry ...
Gharib A A Department of Psychology, University of California, Berkeley 94720-1650, - - 2001
Two rat experiments shed light on how variation in behavior is regulated. Experiment 1 used the peak procedure. On most trials, the 1st bar press more than 40 s after signal onset ended the signal and produced food. Other trials lasted much longer and ended without food. On those trials, ...
Fernandez-Duque E - - 2001
Owl monkeys are small monogamous primates ranging over a wide area extending from Panama to the Chaco region of northern Argentina. The Chaco, an alluvial plain covering over one million km2 of Argentina, Bolivia, Brazil, and Paraguay, consists of a mosaic of grasslands, savannas, xeric thorn forests, and gallery forests. ...
Hare Brian - - 2001
We conducted three experiments on social problem solving by chimpanzees, Pan troglodytes. In each experiment a subordinate and a dominant individual competed for food, which was placed in various ways on the subordinate's side of two opaque barriers. In some conditions dominants had not seen the food hidden, or food ...
Lyons D M DM Department of Psychiatry and Behavioral Science, Stanford University School of Medicine, MSLS Room P111, Stanford, CA 94305-5485, USA. - - 2000
Little is known about frustration-induced changes in stress physiology in humans and nonhuman primates. Here we assess in two experiments with squirrel monkeys plasma levels of pituitary-adrenal stress hormones in conditions designed to provoke frustrative nonreward. In the first experiment 18 prepubertal monkeys were trained to feed from one of ...
Morgan D - - 2000
The present study used a concurrent schedule of food and drug delivery in socially housed male cynomolgus monkeys (Macacafascicularis; N = 15) to study variables that influence cocaine acquisition. Each monkey was implanted with subcutaneous vascular access ports, and responding was maintained under a concurrent food, saline schedule with the ...
Ishibashi H - - 2000
Four Japanese macaques were trained in the use of a T-shaped rake. Use the tool and development of the level of the skill of tool-use took place in three distinct stages. During stage 1, two of the monkeys seemed to use insight for initial solution, while fortuitous experiences led the ...
Westlund K - - 2000
Post-conflict (PC) affiliation has been demonstrated in a number of Old World monkeys and apes, but very little is known about the occurrence of the phenomenon in New World monkeys. This study examined 282 PC interactions after spontaneous conflicts around feeding time in two family groups (N = 12) of ...
Valsecchi P - - 2000
Search abilities of mice (Mus musculus domesticus) were evaluated using an arena closed by a ceiling in which 9 food sources (which mice could reach standing on their hind legs) could be arranged according to 2 configurations: a 3 x 3 square matrix and 3 clusters each containing 3 food ...
de Waal - - 2000
Capuchin monkeys (Cebus apella) share food even if separated by a mesh restraint. Pairs of capuchins were moved into a test chamber in which one of them received apple pieces for 20 min, and the other received carrot pieces for the next 20 min. Previous research had shown a correlation ...
Kirshenbaum AP - - 2000
The literature on risk-sensitive foraging theory provides several accounts of species that fluctuate between risk-averse and risk-prone strategies. The daily energy budget rule suggests that shifts in foraging strategy are precipitated by changes in the forager's energy budget. Researchers have attempted to alter the organism's energy budget using a variety ...
Kieu N T NT Department of Gastroenterology, Research Institute, International Medical Center of Japan, 1-21-1, Toyama, Shinjuku-Ku, Tokyo 162-8655, - - 2000
This study was conducted to investigate the concentrations of serum fatty acids, lipoprotein(a) and apolipoprotein of three populations in North Vietnam: rural area with low income (n = 101), suburban with average income (n = 97), and urban with high income (n = 95). The results showed the suburban and ...
Olthof A A Department of Psychology, University of Western Ontario, London, - - 2000
In each of 3 experiments, different sets of 4 pigeons (Columba livia) were trained to discriminate between 2 visual symbols that covered wells containing food items that varied in number, mass, or both. In Experiment 1, the symbols were associated with 0, 1, 3, 5, 7, or 9 pieces of ...
Dickinson A A Department of Experimental Psychology, University of Cambridge, United Kingdom. - - 2000
The administration of the dopamine antagonists, pimozide and alpha-flupenthixol, to rats reduced Pavlovian-instrumental transfer when a conditioned stimulus (CS) that had been paired with a noncontingent food reward was tested on instrumental performance. The administration of the antagonists during Pavlovian conditioning and/or testing abolished the enhancement of instrumental performance by ...
Hare B - - 2000
We report a series of experiments on social problem solving in chimpanzees, Pan troglodytes. In each experiment a subordinate and a dominant individual were put into competition over two pieces of food. In all experiments dominants obtained virtually all of the foods to which they had good visual and physical ...
Schieber M H MH Department of Neurology, University of Rochester Medical Center, NY 14642, USA. - - 2000
The visual, tactile, and motor properties of neurons in the ventral premotor cortex (PMv) suggest that the PMv plays an important role in the interaction of the face and upper extremities with visual objects, a function that might be disrupted by inactivation of the PMv. The behavior of three rhesus ...
Visalberghi E - - 2000
Palatability of plant foods may change over time in relation to the concentration of toxic secondary metabolites. We investigated the behavioural response of capuchin monkeys to this type of change and assessed the influence of social conditions. Twenty-seven tufted capuchin monkeys were presented in Social or Individual conditions with a ...
Johnson E - - 2000
This study characterizes food neophobia in semi-free ranging rhesus macaques. In experiment one, monkeys received novel and familiar foods during periods of normal provisioning and when provisioning was suspended. The monkeys did discriminate between novel and familiar foods and continued to exhibit neophobia when provisioning was suspended. In experiment two, ...
Roush RS - - 1999
We examined the effects of social environment on food-asociated calling of cotton-top tamarins, Saguinus oedipus, in two experiments. In experiment 1, we compared the food-associated calling behaviour of six juvenile tamarins living in their natal groups with their calling behaviour 9 months after being removed from family groups and paired. ...
Nakagawa N - - 1999
In order to obtain reliable evidence for differences in habitat preferences between two closely related savanna-dwelling primate species, namely, patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus), I collected data on vegetation and patterns of range use concurrently at a single study site, Kala Maloue, Cameroon, in a ...
Hauser MD - - 1999
In any problem-solving situation, there are features associated with the problem that are relevant from a functional perspective and other features that are irrelevant. To determine whether animals are sensitive to the distinction between functionally relevant and irrelvant features of a problem, we conducted two main experiments with a New ...
Beran M J MJ Language Research Center, Georgia State University Decatur 30034, - - 1999
Delay of gratification in 3 chimpanzees (Pan troglodytes) was examined by using a paradigm based on research with children. The chimpanzees either pressed a door-bell button during a trial and received one reward (the immediate reward) or did not press the doorbell and received another reward (the delayed reward). Two ...
Bassareo V V Department of Toxicology and CNR, Center for Neuropharmacology, University of Cagliari, - - 1999
The nucleus accumbens septi is the major target of mesolimbic dopamine neurons originating in the ventral tegmental area of the mesencephalon. Studies involving experimental manipulation of dopamine transmission by drugs and by lesions, as well as in vivo monitoring of extracellular dopamine concentrations, have provided evidence that the dopamine transmission ...
Pakarinen E D - - 1999
The present study assessed the liability of ethanol to be established as an oral reinforcer in 24 juvenile rhesus monkeys. All of the monkeys had a prior oral self-administration history with concurrently available methadone and water. To determine if food restriction and sex differences would contribute to ethanol preference, the ...
Estrada A - - 1999
In Neotropical rain forests, fresh mammal dung, especially that of howler monkeys, constitutes an important resource used by dung beetles as food and for oviposition and further feeding by their larvae. Tropical rain forest destruction, fragmentation, and subsequent isolation causing reductions in numbers of and the disappearance of howler monkeys ...
Laska M - - 1999
The purpose of this study was to determine taste difference thresholds for sucrose in frugivorous spider monkeys and omnivorous baboons. Using a two-bottle preference test of brief duration, we presented four Ateles geoffroyi and four Papio hamdryas anubis with six different reference concentrations (RCs) of 25, 50, 100, 200, 300, ...
Miyazaki K K Laboratory of Brain-operative expression, Brain Science Institute, RIKEN, Wako, Saitama, - - 1998
Single unit recording in rat nucleus accumbens (NAcc) was used to ascertain NAcc neuronal activity in mediating of reward including its anticipation. Of the 103 neurons investigated, 63% showed some response in connection with the task activity. Of these, 20 units responded during delivery of the primary reward (food and/or ...
Tomie A A Department of Psychology, Center of Alcohol Studies, Rutgers University, Piscataway, NJ 08855, - - 1998
Autoshaping conditioned responses (CRs) are reflexive and targeted motor responses expressed as a result of experience with reward. To evaluate the hypothesis that autoshaping may be a form of impulsive responding, within-subjects correlations between performance on autoshaping and impulsivity tasks were assessed in 15 Long-Evans hooded rats. Autoshaping procedures [insertion ...
Parker A - - 1998
Three Cynomolgus monkeys (Macaca fascicularis) learned a flavour-visual conditional discrimination problem, in which one of two possible food items was presented at the beginning of each trial, and acted as an instruction cue to signal which of two visually distinct stimulus objects the animal must displace on that trial in ...
Silberberg A - - 1998
In 5 experiments, 4 monkeys and 1 ape chose between 2 food sources, each held in 1 of the experimenter's hands while he stood in front of a cage. When choosing between 2 sources of the same food that differed in amount, preference for the larger amount decreased as the ...
Hopkins W D WD Division of Psychobiology, Yerkes Regional Primate Research Center, Emory University, Georgia, - - 1998
Hand use in gestural communication was examined in 115 captive chimpanzees (Pan troglodytes). Hand use was measured in subjects while they gestured to food placed out of their reach. The distribution of hand use was examined in relation to sex, age, rearing history, gesture type, and whether the subjects vocalized ...
Novak M A - - 1998
Self-injurious behavior (SIB) occurs in about 10% of individually housed monkeys. Monkeys with SIB bite their own bodies frequently, occasionally inflicting wounds as a result. At present, there is no standard treatment for this phenomenon. We examined the effectiveness of puzzle feeders in alleviating SIB in monkeys with a veterinary ...
Visalberghi E - - 1998
Visalberghi and Fragaszy [Animal Behaviour 49:1089-1095, 1995] have shown that social influences affect acceptance of novel foods. However, little is known about the temporal course on which such influences act (e.g., for how long they persist and for how many encounters they are effective). To explore this issue, 11 adult ...
Isbell L A - - 1998
A 17 month field study of unprovisioned patas monkeys (Erythrocebus patas pyrrhonotus) in Laikipia, Kenya, using both ad libitum and scan sampling techniques, revealed that the diet of patas monkeys consists primarily of gum of Acacia drepanolobium, arthropods (both free-living and concentrated in the swollen thorns of A. drepanolobium), and ...
Masterson T J - - 1997
Ontogenetic patterns of sexual dimorphism and cranial form in two capuchin monkeys, Cebus albifrons and C. apella, are investigated by means of univariate, bivariate, and multivariate statistics. The analyses are based on 23 linear variables. Univariate analyses indicate that similar ontogenetic patterns of cranial sexual dimorphism are present; however, interspecific ...
de Waal F B - - 1997
Capuchin monkeys (Cebus apella) share food even if their partner is behind a mesh restraint. Pairs of adult capuchins were moved into a test chamber in which 1 monkey received cucumber pieces for 20 min and the other received apple slices during the following 20 min. Tolerant transfers of food ...
DeCoteau W E WE Department of Psychology, University of Utah, Salt Lake City 84112, - - 1997
Memory for magnitude of reinforcement was assessed in rats using a go/no-go short-term memory paradigm. During the task's study phase rats were given a piece of cereal comprised of either 25 or 50% sugar. For all trials, one of the cereal types was designated positive, the other negative. On the ...
Schedin U - - 1997
BACKGROUND: High amounts of endogenous nitric oxide (NO) have been demonstrated in the human upper airway, but the role of nasal NO is still unclear. The present study aims to describe nasal NO excretion in different animal species with special living conditions or anatomy. METHODS: Domestic animals (horse, cow, pig, ...
Salinas J A JA Department of Psychology, University of Virginia, Charlottesville 22903, USA. - - 1997
These experiments examined the effects of posttraining intraamygdala administration of the muscarinic agonist, oxotremorine, and the beta-noradrenergic antagonist, propranolol, on memory for reduction in reward magnitude. Male Sprague-Dawley rats (175-200 g) implanted with bilateral intraamygdala cannulae were food deprived (maintained at 80% of body weight) and trained to run a ...
Bolen R H - - 1997
The authors tested free-ranging New World monkeys (nocturnal owl monkeys [Aotus nancymai] and diurnal capuchin monkeys [Cebus apella]) to determine the extent to which they use olfactory cues to locate food hidden in containers at 2 of 6 feeding sites within a 1 1/2-ha forested enclosure. These 2 sites were ...
Snowdon C T - - 1997
Affiliative behavior is often expressed through communication, and the nature of affiliative interactions affects the ontogeny of communication. I presented three phenomena that demonstrate the importance of affiliation in vocal development in marmosets and tamarins, but the results have parallels in many other species including birds, dolphins, and humans. Pygmy ...
Westergaard G C - - 1997
This research investigated the effects of posture on lateral bias for food reaching in tufted capuchin monkeys ( Cebus apella ) by comparing hand preferences for quadrupedal and bipedal reaching. Several findings of this investigation warrant discussion. First, we found a population-level bias towards use of the right hand for ...
Garber P A - - 1997
Despite a large body of data on diet and ranging patterns in prosimians, monkeys and apes, little is known regarding the types of information that non-human primates use when making foraging decisions. In a series of controlled field experiments, we tested the ability of wild capuchins (Cebus capucinus) at La ...
Westergaard G C - - 1997
This research examined tool and food transfer between two groups of tufted capcuhin monkeys (Cebus apella). Subjects in one group transferred stones to subjects in a second group who in turn used the stones as cutting tools and then transferred food to subjects in the first group. Aspects of the ...
Westergaard G C - - 1996
This research examined hand preference for a bimanual task in 45 tufted capuchin (Cebus apella) and 55 rhesus macaque (Macaca mulatta) monkeys. Investigators presented subjects with plastic tubes lined with food and noted which hand the animals used to hold the tubes and which hand the animals used to remove ...
Josselyn S A - - 1996
Cholecystokinin (CCK) is an endogenous peptide that is colocalized with dopamine (DA) in some mesolimbic neurons projecting to the nucleus accumbens (NAC). DA has been implicated in the acquisition of conditioned rewarding properties by neutral stimuli [conditioned stimuli (CS)] associated with a primary reward (such as food). A variety of ...
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