| Home | << 1 2 3 4 5 6 7 8 9 10 >> [11–14] |
|
Tomasello, M., Call, J., & Hare, B. (1998). Five primate species follow the visual gaze of conspecifics. Anim. Behav., 55(4), 1063–1069.
Abstract: Individuals from five primate species were tested experimentally for their ability to follow the visual gaze of conspecifics to an outside object. Subjects were from captive social groups of chimpanzees,Pan troglodytes, sooty mangabeys,Cercocebus atys torquatus, rhesus macaques,Macaca mulatta, stumptail macaques,M. arctoides, and pigtail macaques,M. nemestrina. Experimental trials consisted of an experimenter inducing one individual to look at food being displayed, and then observing the reaction of another individual (the subject) that was looking at that individual (not the food). Control trials consisted of an experimenter displaying the food in an identical manner when the subject was alone. Individuals from all species reliably followed the gaze of conspecifics, looking to the food about 80% of the time in experimental trials, compared with about 20% of the time in control trials. Results are discussed in terms of both the proximate mechanisms that might be involved and the adaptive functions that might be served by gaze-following.
|
|
Brannon, E. M., & Terrace, H. S. (1998). Ordering of the numerosities 1 to 9 by monkeys. Science, 282(5389), 746–749.
Abstract: A fundamental question in cognitive science is whether animals can represent numerosity (a property of a stimulus that is defined by the number of discriminable elements it contains) and use numerical representations computationally. Here, it was shown that rhesus monkeys represent the numerosity of visual stimuli and detect their ordinal disparity. Two monkeys were first trained to respond to exemplars of the numerosities 1 to 4 in an ascending numerical order (1 --> 2 --> 3 --> 4). As a control for non-numerical cues, exemplars were varied with respect to size, shape, and color. The monkeys were later tested, without reward, on their ability to order stimulus pairs composed of the novel numerosities 5 to 9. Both monkeys responded in an ascending order to the novel numerosities. These results show that rhesus monkeys represent the numerosities 1 to 9 on an ordinal scale.
|
|
Schnall, S., & Gattis, M. (1998). Transitive Inference by Visual Reasoning.
Abstract: Two experiments are reported that investigated the influence
of linear spatial organization on transitive inference performance. Reward/no-reward relations between overlapping pairs of elements were presented in a context of linear spatial order or random spatial order. Participants in the linear arrangement condition showed evidence for visual reasoning: They systematically mapped spatial relations to conceptual relation and used the spatial relations to make inferences on a reasoning task in a new spatial context. We suggest that linear ordering may be a “good figure”, by constituting a parsimonious representation for the integration of premises, as well as for the inferencing process. The late emergence of transitive inference in children may be the result of limited cognitive capacity, which --unless an external spatial array is available --constrains the construction of an internal spatial array. |
|
Schooening, B. (1998). Ethology of the horse. Prakt. Tierarzt, 79(6 Suppl.), 25–28.
Abstract: The paper starts with a short introduction/definition about ethology and the used methods in this scientific field, giving special examples for horses and about how their “normal behaviour” is measured. The behaviour repertoire of horses is described in a brief outline with special emphasis on their social systems and hierarchies and the problem of dominance, especially in interaction with humans. Schlütersche GmbH & Co. KG, Verlag und Druckerei.
Keywords: Dominance; Ethology; Horse; Propedeutics
|
|
Kendrick, K. M. (1998). Intelligent perception. Appl. Anim. Behav. Sci., 57(3-4), 213–231.
Abstract: For an animal from any species to exhibit intelligent perception it must be capable of being consciously aware of what it perceives and capable of learning from this experience. Although many organisms, and for that matter machines, are capable of rapid adaptive learning in response to perception of environmental changes, such adaptations can occur without them being consciously aware either of external stimuli or their response to them. While behavioural and neurophysiological evidence suggests that, apart from ourselves, other higher primates must also be capable of such awareness, an important central question is whether such awareness is a characteristic of primate evolution or if it also occurs in sub-primate mammals as well. In this review I will examine our behavioural and neurophysiological evidence from visual and olfactory recognition studies in the sheep to support the argument that they are likely to be aware of and learn about both social and non-social objects and that they are therefore capable of intelligent perception. However, the impact of motivational changes on these perceptual processes suggests that they may be limited in terms of both prospection and retrospection and dealing with symbolic associations.
Keywords: Intelligent perception; Environmental changes; Primates
|
|
Cooper, J. J. (1998). Comparative learning theory and its application in the training of horses. Equine Vet J Suppl, (27), 39–43.
Abstract: Training can best be explained as a process that occurs through stimulus-response-reinforcement chains, whereby animals are conditioned to associate cues in their environment, with specific behavioural responses and their rewarding consequences. Research into learning in horses has concentrated on their powers of discrimination and on primary positive reinforcement schedules, where the correct response is paired with a desirable consequence such as food. In contrast, a number of other learning processes that are used in training have been widely studied in other species, but have received little scientific investigation in the horse. These include: negative reinforcement, where performance of the correct response is followed by removal of, or decrease in, intensity of a unpleasant stimulus; punishment, where an incorrect response is paired with an undesirable consequence, but without consistent prior warning; secondary conditioning, where a natural primary reinforcer such as food is closely associated with an arbitrary secondary reinforcer such as vocal praise; and variable or partial conditioning, where once the correct response has been learnt, reinforcement is presented according to an intermittent schedule to increase resistance to extinction outside of training.
|
|
Drummond, H., & Canales, C. (1998). Dominance between booby nestlings involves winner and loser effects. Anim. Behav., 55(6), 1669–1676.
Abstract: Two-chick broods of the blue-footed booby,Sula nebouxii, ordinarily exhibit stable dominance-subordinance, with the senior (first-hatched) chick habitually aggressive and the junior one habitually submissive (Nelson 1978,The Sulidae: Gannets and Boobies. London: Oxford University Press). But are both the subordinate and the dominant chick affected in their agonistic tendencies by early social experience? To answer this, we permanently paired subordinate and dominant chicks, 2-3 weeks old, with singletons (chicks lacking experience with a nestmate) by cross-fostering. During the first 4 h after pairing, subordinate chicks were seven times less aggressive than singletons and twice as likely to be submissive; dominant chicks were six times as aggressive as singletons. Although most subordinates consistently lost agonistic encounters during the first 10 days after pairing, the proportion of dominants that won decreased progressively until, by day 6, only about half of dominant chicks were winning. Early social experience has a strong but reversable training effect on both subordinates and dominants. Training as a subordinate showed more persistent effects than training as a dominant, possibly in part because our testing situation perpetuated subordinate training and counteracted dominant training.
|
|
Karavanich, C., & Atema, J. (1998). Individual recognition and memory in lobster dominance. Anim. Behav., 56(6), 1553–1560.
Abstract: American lobsters,Homarus americanus, form stable dominance relationships in captivity. Size, sex and stage in the moult cycle are important determinants for dominance. Other factors, such as recent agonistic experience play a role. This paper investigates how lobsters maintain their stable dominance relationships: they may recognize individuals or alternatively, recognize overall dominance status. We paired lobsters in two consecutive `boxing matches'. Results indicate that lobsters remember familiar opponents when kept either in isolation or in communal tanks for 24 h between their first and second fights. Subordinates immediately backed away from familiar dominants, avoiding a second fight. In some animals, this memory lasted between 1-2 weeks if pairs were kept separate between the first and second fights. When paired for the second fight against unfamiliar dominant lobsters, subordinate lobsters from first fights actively fought and won the encounter. These results suggest that lobsters are capable of `individual recognition'. In nature, the observed social organization of lobsters may be maintained by individual recognition of a small number of residents inhabiting separate, nearby shelters.
|
|
Schnitzer, U. (1998). Grundsätze der Gymnastizierung des Reitpferdes.
|
|
Bürger, U. (1998). The Way to perfect Horsemanship. Trafalgar Square Publishing.
Abstract: The Way to Perfect Horsemanship is an outstanding work in the vast literature devoted to horsemanship. It provides, for the first time, a clear insight into the psychological makeup of the horse, its muscular system, the mechanics of its movement, and the aids to human-to-horse communication. Udo Burger presents his philosophy of riding in a scientific manner, asserting that no one can no more learn to ride without a knowledge of horse physiology and psychology than one can learn the art of medecine without a background in health and disease. He clearly explains what one should feel and do on horseback--ultimately, as if one is part of the horse, completely united with it in all of its movements. Anyone with a genuine empathy for horses--wether teacher, trainer, competitor, or occasional rider--will benefit enormously from reading this classic work on horsemanship. The late Udo Burger was an accomplished horseman and one of Germany's most esteemed equine veterinarians.
|