Search Results
Results 301 - 350 of 636
< 2 3 4 5 6 7 8 9 10 11 12 >
Call Josep - - 2007
Four bonobos, seven gorillas, and six orangutans were presented with two small rectangular boards on a platform. One of the boards had a piece of food under it so that it acquired an inclined orientation whereas the other remained flat on the platform. Subjects preferentially selected the inclined board. In ...
Aoki Naoya - - 2006
Behavioral effects of handling cost (time and/or energetic cost for food consumption) on choice were examined using domestic chicks trained in operant task reinforced by delayed food rewards. When scattered sesame was delivered in more demanding conditions, a colored cue bead associated with six grains ('large' and 'costly' reward) was ...
Darmaillacq Anne-Sophie - - 2006
Imprinting provides precocial offspring with an efficient means to optimize their subsequent behaviours. We discovered food imprinting using a sophisticated invertebrate model: the cuttlefish. We showed that early juveniles preferred the prey to which they have been visually familiarized, when the amount of information was sufficient and only if such ...
Bauman M D - - 2006
As part of ongoing studies on the neurobiology of socioemotional behavior in the nonhuman primate, the authors examined the social dominance hierarchy of juvenile macaque monkeys (Macaca mulatta) that received bilateral ibotenic acid lesions of the amygdala or the hippocampus or a sham surgical procedure at 2 weeks of age. ...
Beran Michael J MJ Language Research Center, Georgia State University, P.O. Box 5010, Atlanta, GA 30303, United States. mjberan@yahoo.com - - 2006
Previous research in our laboratory has demonstrated that chimpanzees can delay gratification by inhibiting consumption of available food items for as long as 3 min as an experimenter transfers additional food items from a transparent container to a bowl placed in front of the subject. In this study, we examined ...
Southgate Victoria V University of St. Andrews, St. Andrews, Scotland, UK. - - 2006
The reasons underpinning search biases in 2 species of macaque monkeys (Macaca mulatta and Macaca arctoides) were explored over the course of 3 experiments requiring monkeys to search for a hidden food reward. The results reveal that monkeys are adept at exploiting perceptual cues to locate a food reward but ...
Wise Roy A RA Intramural Research Program, Department of Health and Human Services, National Institute on Drug Abuse, Baltimore, MD 21224, USA. - - 2006
The ability of food to establish and maintain response habits and conditioned preferences depends largely on the function of brain dopamine systems. While dopaminergic transmission in the nucleus accumbens appears sufficient for some forms of reward, the role of dopamine in food reward does not appear to be restricted to ...
Davis Caroline C Department of Kinesiology & Health Sciences, York University, and Centre for Addiction and Mental Health, Toronto, Ontario, Canada. - - 2007
The reinforcing effects of addictive drugs and palatable foods are regulated, at least in part, by a common biological mechanism. The reactivity or sensitivity of these brain reward regions have been found to correlate significantly with the risk for a variety of drug addictions. Sensitivity to Reward (STR) is conceptualised ...
Brosnan Sarah F SF Living Links Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, USA. - - 2006
It was recently demonstrated that capuchin monkeys notice and respond to distributional inequity, a trait that has been proposed to support the evolution of cooperation in the human species. However, it is unknown how capuchins react to inequitable rewards in an unrestricted cooperative paradigm in which they may freely choose ...
Cohen Yale E - - 2006
In various aspects of linguistic analysis and human cognition, some forms of observed variation are ignored in the service of handling more abstract categories. In the absence of training, rhesus discriminate between different types of vocalizations based on the information conveyed as opposed to their acoustic morphologies. We hypothesized that ...
Dubreuil Diane - - 2006
It has been reported that capuchin monkeys reject a less preferred food (LPF) when they see a partner capuchin receive a more preferred food (PF) for performing the same task. This behaviour was taken as evidence of 'inequity aversion', but an alternative hypothesis is that capuchins reject the LPF because ...
Beaver John D JD Brain Sciences Unit, Medical Research Council Cognition, Cambridge CB2 2EF, United Kingdom. - - 2006
A network of interconnected brain regions, including orbitofrontal, ventral striatal, amygdala, and midbrain areas, has been widely implicated in a number of aspects of food reward. However, in humans, sensitivity to reward can vary significantly from one person to the next. Individuals high in this trait experience more frequent and ...
Jersáková Jana - - 2006
The orchid family is renowned for its enormous diversity of pollination mechanisms and unusually high occurrence of non-rewarding flowers compared to other plant families. The mechanisms of deception in orchids include generalized food deception, food-deceptive floral mimicry, brood-site imitation, shelter imitation, pseudoantagonism, rendezvous attraction and sexual deception. Generalized food deception ...
Burkart Judith - - 2006
A series of experiments investigating the degree of gaze understanding in common marmosets (Callithrix jacchus) is reported. Results show that marmosets follow the gaze of a human experimenter readily and also use the gaze to locate food in a modified version of the object choice task if influences of chance ...
Evans Theodore Avery TA Alpha Genesis, Inc., Yemassee, SC 29945, USA. - - 2006
Self-control is defined as forgoing immediate gratification to obtain a greater reward. Tool use may relate to self-control because both behaviors may require foresight and deliberate control over one's actions. The authors assessed 20 capuchin monkeys (Cebus apella) for the ability to delay gratification in a tool task. Subjects were ...
Buzzard Paul J - - 2006
Forest guenons (Cercopithecus spp.) are often found in polyspecific associations that may decrease predator risk while increasing interspecific competition for food. Cheek pouch use may mitigate interspecific competition and predator risk by reducing the time spent in areas of high competition/predator risk. I investigated these ideas in three forest guenons: ...
Lavenex Pamela Banta - - 2006
The role of the hippocampus in spatial learning and memory has been extensively studied in rodents. Comparable studies in nonhuman primates, however, are few, and findings are often contradictory. This may be attributable to the failure to distinguish between allocentric and egocentric spatial representations in experimental designs. For this experiment, ...
Elman Igor I Behavioral Psychopharmacology Research Laboratory, Department of Psychiatry, McLean Hospital and Harvard Medical School, Belmont, MA 02478, USA. - - 2006
Obesity is highly prevalent among patients with schizophrenia and is associated with detrimental health consequences. Although excessive consumption of fast food and pharmacotherapy with such second-generation antipsychotic agents (SGAs) as clozapine and olanzapine has been implicated in the schizophrenia/obesity comorbidity, the pathophysiology of this link remains unclear. Here, we propose ...
Sastre Aristides A Department of Psychology, University of Illinois at Chicago, 1007 West Harrison Street, Chicago, IL 60607, - - 2006
Lesions of the gustatory thalamus (GT) prevent the occurrence of between-session contrast effects (i.e., anticipatory negative contrast and consummatory successive negative contrast [cSNC]) involving liquid rewards. These deficits are attributed to a disruption of the reward comparison mechanism that computes the value of the current reward relative to the expected ...
Roberts Seth S Department of Psychology, University of California, Berkeley, CA 94708, USA. - - 2006
Instrumental learning involves both variation and selection: variation of what the animal does, and selection by reward from among the variation. Four experiments with rats suggested a rule about how variation is controlled by recent events. Experiment 1 used the peak procedure. Measurements of bar-press durations showed a sharp increase ...
White Norman M - - 2006
Learning to discriminate between spatial locations defined by two adjacent arms of a radial maze in the conditioned cue preference paradigm requires two kinds of information: latent spatial learning when the rats explore the maze with no food available, and learning about food availability in two spatial locations when the ...
Roma Peter G - - 2006
Each of 4 female capuchin monkeys ("model") was paired with another female capuchin ("witness") in an adjacent cage. In Phases 1 and 3, a model could remove a grape from the experimenter's hand while the witness watched. The witness was then offered a slice of cucumber, a less preferred food. ...
Ramseyer A - - 2006
Delayed reciprocity is a potentially important mechanism for cooperation to occur. It is however rarely reported among animals, possibly because it requires special skills like the ability to plan a loss. We tested six brown capuchin monkeys (Cebus apella) in such skills. Subjects were studied in exchange tasks in which ...
Vlamings Petra H J M - - 2006
S. T. Boysen and G. G. Berntson (1995) found that chimpanzees performed poorly on a reversed contingency task in which they had to point to the smaller of 2 food quantities to acquire the larger quantity. The authors compared the performance of 4 great ape species (Pan troglodytes, Pongo pygmaeus, ...
Peciña Susana S Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA. - - 2006
Corticotropin-releasing factor (CRF) is typically considered to mediate aversive aspects of stress, fear and anxiety. However, CRF release in the brain is also elicited by natural rewards and incentive cues, raising the possibility that some CRF systems in the brain mediate an independent function of positive incentive motivation, such as ...
Roth Megan E ME Alcohol and Drug Abuse Research Center, Department of Psychiatry, McLean Hospital/Harvard Medical School, Belmont, MA 02478, - - 2005
Clinical and preclinical data suggest that fluctuations in ovarian steroid hormones across the menstrual/estrous cycle influence spontaneous feeding behavior in females. The effects of gender, menstrual cycle phase, and ovarian hormone fluctuations on food-maintained responding under a progressive-ratio schedule were investigated in four female and three male cynomolgus monkeys. Females ...
Aoki Naoya N Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, - - 2006
The effects of bilateral chemical lesions of the ventral striatum (nucleus accumbens and the surrounding areas in the medial striatum) and arcopallium (major descending area of the avian telencephalon) were examined in 1-2-weeks old domestic chicks. Using a Y-maze, we analyzed the lesion effects on the choices that subject chicks ...
Cagniard Barbara B Department of Neurobiology, Pharmacology and Physiology, The University of Chicago, Chicago, IL 60637, USA. - - 2006
Dopamine has been critically implicated in learning and motivation, although its precise role remains to be determined. In order to investigate the involvement of dopamine in learning and motivation for a food reward, we used dopamine transporter knockdown mice (DAT KD) that have chronically elevated levels of extracellular dopamine. The ...
Santos Laurie R - - 2005
The authors examined how 2 lemur species (Eulemur fulvus and Lemur catta) reason about tools. Experiment 1 allowed subjects to use 1 of 2 canes to retrieve an inaccessible food reward. Lemurs learned to solve this problem as quickly as other primates. Experiment 2 then presented subjects with novel tools ...
Hopkins William D WD Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA. - - 2005
Humans throw right-handed, and it has been suggested that the neurophysiological demands of aimed throwing may have served as a precursor to the evolution of left hemisphere specialization for linguistic functions. Although there are descriptions of throwing by wild and captive chimpanzees (Pan troglodytes), systematic observations of aimed throwing and ...
Silk Joan B JB Department of Anthropology, University of California, Los Angeles, California 90095, USA. - - 2005
Humans are an unusually prosocial species-we vote, give blood, recycle, give tithes and punish violators of social norms. Experimental evidence indicates that people willingly incur costs to help strangers in anonymous one-shot interactions, and that altruistic behaviour is motivated, at least in part, by empathy and concern for the welfare ...
Balleine Bernard W BW Department of Psychology and the Brain Research Institute, University of California, Box 951563, Los Angeles, CA 90095-1563, United States. - - 2005
Recent studies suggest that there are multiple 'reward' or 'reward-like' systems that control food seeking; evidence points to two distinct learning processes and four modulatory processes that contribute to the performance of food-related instrumental actions. The learning processes subserve the acquisition of goal-directed and habitual actions and involve the dorsomedial ...
Ohmura Yu Y Department of Behavioral Science, Hokkaido University, N10 W7 Kita-ku, Sapporo, 060-0810, Japan. - - 2005
Nicotine dependence has been associated with impulsivity and discounting delayed/uncertain outcomes. This study had two main objectives: (1) to examine the relationship between the number of cigarettes consumed per day and the degree to which delayed and uncertain monetary gains and losses are discounted by smokers, and (2) to determine ...
Franken Ingmar H A - - 2005
According to the theory of J.A. Gray, a strongly reactive approach system is highly sensitive to reward or to cues that signal reward. This implies that intake driven by the rewarding properties of food should be affected by individual differences in reactivity of the approach system. The present study examined ...
Paukner Annika - - 2006
This study investigated capuchin monkeys' understanding of their own visual search behavior as a means to gather information. Five monkeys were presented with three tubes that could be visually searched to determine the location of a bait. The bait's visibility was experimentally manipulated, and the monkeys' spontaneous visual searches before ...
Yonghui Li L Institute of Psychology, Chinese Academy of Sciences; Laboratory of Mental Health, Chinese Academy of Sciences, P.R. China. - - 2006
Behavioural studies have provided strong evidence for common substrates in the rewards of natural and addictive substances, but it is still unclear whether there is a common glutamatergic NMDA receptor mechanism involved in the processing of reward for both. The present study was designed to investigate the effects of MK-801 ...
Izawa Ei-Ichi E Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-601, - - 2005
To identify the neuro-cognitive substrates of valuation and choice, we analysed the neural correlates of anticipated food rewards in the ventral striatum of freely behaving chicks. One-week-old chicks were trained in a color-discrimination task using four color cues (red, yellow, green and blue), each of which was associated with a ...
Herzig Volker V Neuropharmacology, Zoological Institute, Faculty of Biology, University of Tübingen, Germany. - - 2005
Recent studies have revealed the effectiveness of 2-methyl-6-(phenylethynyl)pyridine (MPEP), a highly selective antagonist of metabotropic glutamate receptors subtype 5 (mGluR5), in conditioned drug reward. In a previous study we showed that MPEP blocks expression of context-conditioned morphine- but not cocaine reward in the rat. The present study now examines the ...
O'Malley Robert C - - 2005
Interpopulation variability in patterns of food processing, similar to what is described as "traditional" or "cultural" variation in chimpanzees (Pan troglodytes) and orangutans (Pongo pygmaeus), was identified in white-faced capuchins (Cebus capucinus). However, recent comparisons of food processing in capuchins were conducted only at the population level, with relatively little ...
Bicca-Marques Júlio César JC Pontifícia Universidade Católica do Rio Grande do Sul, Brazil. - - 2005
Rainforest primates need to apply distinct foraging rules for efficiently using the spatial knowledge of the distribution of resources showing different temporal patterns of renewal. A win-stay rule is very important for exploiting abundant, long-lasting resources. Here, the author tests the use of this rule in wild groups of emperor ...
Padoa-Schioppa Camillo - - 2006
We studied economic choice behavior in capuchin monkeys by offering them to choose between two different foods available in variable amounts. When monkeys selected between familiar foods, their choice patterns were well-described in terms of relative value of the two foods. A leading view in economics and biology is that ...
Beran Michael J - - 2005
Two chimpanzees and a rhesus macaque rapidly learned the ordinal relations between 5 colors of containers (plastic eggs) when all containers of a given color contained a specific number of identical food items. All 3 animals also performed at high levels when comparing sets of containers with sets of visible ...
Stevens Jeffrey R JR Department of Psychology and Primate Cognitive Neuroscience Laboratory, Harvard University, Cambridge, MA 02138, USA. - - 2005
Decision making often involves choosing between small, short-term rewards and large, long-term rewards. All animals, humans included, discount future rewards--the present value of delayed rewards is viewed as less than the value of immediate rewards. Despite its ubiquity, there exists considerable but unexplained variation between species in their capacity to ...
Anapol F - - 2005
Body weight and length, chest girth, and seven postcranial limb segment lengths are compared between two guenon species, Chlorocebus (Cercopithecus) aethiops (vervets) and Cercopithecus mitis (blue monkeys), exhibiting different habitual locomotor preferences. The subjects, all adults, were wild caught for a non-related research project (Turner et al. [1986] Genetic and ...
Drapier Maud M Centre d'Ecologie, Physiologie et Ethologie, Centre National de la Recherche Scientifique, UPR 9010, Strasbourg, - - 2005
To assess how brown capuchin monkeys (Cebus apella) delay gratification and maximize payoff, we carried out four experiments in which six subjects could exchange food pieces with a human experimenter. The pieces differed either in quality or quantity. In qualitative exchanges, all subjects gave a piece of food to receive ...
Wellman Laurie L LL Interdisciplinary Program in Neuroscience and Department of Pharmacology, Georgetown University, Washington, DC 20007, - - 2005
Amygdala ablation disrupts reinforcer "devaluation" in monkeys (Malkova et al., 1997). Here, we tested the hypothesis that transient inactivation of amygdala by the GABA(A) agonist muscimol (MUS), specifically during the period of reward satiation, would have a similar effect. Six pigtail macaques were trained on a visual object discrimination task ...
Cummins-Sebree Sarah E - - 2005
Cotton-top tamarins (Saguinus oedipus) selected canes positioned so that a straight inward pull brought food within reach (M. D. Hauser, 1997; see also record 1997-41347-003). Tamarins failed to retrieve food with canes in other positions, and they did not reposition these canes. In this study, tufted capuchin monkeys (Cebus apella) ...
Wilson Fraser A W - - 2005
We describe a custom-built feeder based on stepping motor technology controlled by a laboratory computer. The feeder dispenses a wide range of foods: any fruit, vegetable, or nut. The feeder allows the investigator to reward monkeys with different foods within a single experimental day. The monkey's motivation to perform tasks ...
Hermer-Vazquez Linda L Department of Physiology and Pharmacology, SUNY Health Science Center, Brooklyn, NY 11203, USA. - - 2005
Two groups of rats, one rewarded with sweetened food and the other rewarded with medial forebrain bundle (MFB) stimulation, were trained to home in on and dig for a buried object coated with a target odor. After each group had 15 training trials, MFB rats searched with greater accuracy and ...
Brown Gillian R - - 2005
Infant marmosets and tamarins obtain solid food items from adults during and after the time of weaning. In addition to providing nutrients, food transfers may provide infants with the opportunity to learn about diet. The aim of this study was to investigate patterns of begging and food transfer in captive ...
< 2 3 4 5 6 7 8 9 10 11 12 >