| Home | [1–10] << 11 12 13 14 >> |
|
Dunbar, R. I. M. (1998). The social brain hypothesis. Evol. Anthropol., 6(5), 178–190.
Abstract: Conventional wisdom over the past 160 years in the cognitive and neurosciences has assumed that brains evolved to process factual information about the world. Most attention has therefore been focused on such features as pattern recognition, color vision, and speech perception. By extension, it was assumed that brains evolved to deal with essentially ecological problem-solving tasks. © 1998 Wiley-Liss, Inc.
|
|
Penn, D., & Potts, W. K. (1998). Untrained mice discriminate MHC-determined odors. Physiol. Behav., 64(3), 235–243.
Abstract: PENN, D. AND W. K. POTTS. Untrained mice distinguish MHC-determined odors. PHYSIOL BEHAV 64(3) 235-243, 1998.--Immune recognition occurs when foreign antigens are presented to T-lymphocytes by molecules encoded by the highly polymorphic genes of the major histocompatibility complex (MHC). House mice (Mus musculus) prefer to mate with individuals that have dissimilar MHC genes. Numerous studies indicate that mice recognize MHC identity through chemosensory cues; however, it is unclear whether odor is determined by classical, antigen-presenting MHC loci or closely linked genes. Previous studies have relied on training laboratory mice and rats to distinguish MHC-associated odors, but there are several reasons why training experiments may be inappropriate assays for testing if MHC genes affect odor. The aim of this study was to determine whether classical MHC genes affect individual odors and whether wild-derived mice can detect MHC-associated odors without training. In the first experiment, we found that wild-derived mice can be trained in a Y-maze to detect the odors of mice that differ genetically only in the MHC region. In the second and third experiments, we used a naturalistic habituation assay and found that wild-derived mice can, without training, distinguish the odors of mice that differ genetically only at one classical MHC locus (dm2 mutants).
|
|
Müller-Wohlfahrt, H. W., Kübler, U., & Müller- Wohlfahrt, H. W. (1998). Hundert Prozent fit und gesund. Das Geheimnis des gesunden Menschen. München: Heyne.
|
|
Redbo, I., Redbo-Torstensson, P., Ödberg, F. O., Hedendahl, A., & Holm, J. (1998). Factors affecting behavioural disturbances in race-horses. Animal Science, 66(2), 475–481.
|
|
Wanker, R., Apcin, J., Jennerjahn, B., & Waibel, B. (1998). Discrimination of different social companions in spectacled parrotlets ( Forpus conspicillatus ): evidence for individual vocal recognition. Behav. Ecol. Sociobiol., 43(3), 197–202.
Abstract: Abstract: Individual recognition is generally assumed to be a prerequisite for establishing and maintaining a complex social system. Indeed, there is good evidence that highly social species have complex systems of vocal communication with individual recognition by acoustic cues. In this study, we provide experimental evidence that vocal class and individual recognition is present in a non-passerine bird, the spectacled parrotlet (Forpus conspicillatus). Spectacled parrotlets live in a complex system of social relationships. Soon after fledging, the young establish close sibling relationships which are important for successful socialization, pairing and reproduction. In a series of playback experiments we tested if spectacled parrotlets use contact calls for vocal recognition. The results showed that spectacled parrotlets discriminate between the contact calls of different social categories. Adult birds preferred to respond to the contact calls of their mates. Subadult individuals recognized the contact calls of their siblings. During the period of pair bond formation, the affiliative contacts to the siblings decrease, but the parrotlets continue to respond to the calls of their siblings. This is the first evidence that vocal sibling recognition might outlast the period of strong sibling interaction and extends into the period of pair bond formation. In cases of mate loss or divorce, the acoustic contact to their siblings might facilitate the re-establishment of close sibling relationships.
|
|
Gatta, D., Baragli, P., Ferrarini, N., Ciattini, F., Sighieri, C., & Colombani, B. (1998). Fitness evaluation in endurance horses by standardised exercise test on treadmill. Valutazione dello stato di allenamento del cavallo da endurance mediante test standardizzato su trea, 9(4), 57–69.
Abstract: Endurance horses, like marathon runners, undertake sub-maximal, longterm physical exercises and in both cases thermoregulation plays a critical role. A standardised sub-maximal treadmill test was used to assess fitness and training state in endurance horses. Literature reports that trained human athletes dissipate head load better than not trained ones; in this study parameters related to thermoregulation were recorded together with other haematologic and metabolic ones. Six endurance horses, divided into two groups according to their training state, performed two submaximal tests at a distance of one week. Blood samples were collected at rest, during exercise, at the end and during recovery (10, 30 and 60 minutes after work). Heart rate (HR), respiratory rate (RR), rectal (RT) and skin (ST) temperatures were monitored through the exercise (and recovery for HR). HR resulted significantly lower (P<0.01) in trained horses than in untrained ones, especially during recovery. Also rectal and skin temperatures resulted significantly lower (P<0.05) in trained horses and ST increased more gradually during exercise. The values of haematocrit and haemoglobin resulted significantly lower (P<0.05) at rest, during exercise and recovery samples. In this study, the parameters related to thermoregulation, in accordance with data from human athletes, resulted significantly different in trained and untrained horses, while other parameters didn't vary significantly between the two groups. Thermoregulatory responses to exercise-generated heat load in a standardised test, studied by simple parameters, can thus offer useful information about fitness and training state of endurance horses.
|
|
Shettleworth, S. J. (1998). Cognition, Evolution and Behaviour. Oxford: Oxford University Press.
Abstract: Description
How do animals perceive the world, learn, remember, search for food or mates, and find their way around? Do any non-human animals count, imitate one another, use a language, or think as we do? What use is cognition in nature and how might it have evolved? Historically, research on such questions has been fragmented between psychology, where the emphasis has been on theoretical models and lab experiments, and biology, where studies focus on evolution and the adaptive use of perception, learning, and decision-making in the field. Cognition, Evolution and the Study of Behavior integrates research from psychology, behavioral ecology, and ethology in a wide-ranging synthesis of theory and research about animal cognition in the broadest sense, from species-specific adaptations in fish to cognitive mapping in rats and honeybees to theories of mind for chimpanzees. As a major contribution to the emerging discipline of comparative cognition, the book is an invaluable resource for all students and researchers in psychology, zoology, behavioral neuroscience. It will also interest general readers curious about the details of how and why animals--including humans--process, retain, and use information as they do. Reviews “This book is a very comprehensive review of animal cognition. It differs from other texts on this topic in a number of ways, as outlined by Shettleworth in her preface and in the opening chapter. Essentially, Shettleworth wants to advocate an 'adaptationist or ecological approach to cognition'. In doing so, she brings together a wealth of data on animal cognition, studied from quite different theoretical viewpoints, such as cognitive ethology, animal learning theory, neuroscience, behavioural ecology and cognitive psychology. . . . Each chapter ends with a clear and useful summary, and helpful suggestions for further reading. The book's numerous illustrations, which are mostly tables or figures redrawn by Margaret Nelson, greatly add to its appeal. . . . [T]his is a marvellously rich, well-written and stimulating book. . . . I greatly enjoyed reading [and] recommend it highly to anyone interested in animal cognition, evolution and behaviour.”--Animal Behaviour “Sara Shettleworth has probably written the most comprehensive study of the animal mind ever and therefore a fundamental textbook on 'comparative cognition'. She first gets consciousness out of the way: whether an animal is conscious or not is impossible to determine, since consciousness is a private, subjective phenomenon. We can study cognition, and certainly cognition lends credibility to the idea that at least some animals must be at least to some degree conscious, but experiments can only prove facts about cognition. She reviews the field of cognitive ethology from the beginning and then analyzes the main cognitive tasks from an information-processing perspective By the end of her review of cognitive faculties, it become apparent that, at least among vertebrates, there are no significant differences in learning, except for language. All vertebrates are capable of 'associative' learning What no other vertebrate seems to be capable of is 'syntax'.” -- Piero Scaruffi, Thymos.com |
|
Dunbar, R. I. M., & Bever, J. (1998). Neocortex size predicts group size in carnivores and some insectivores. Ethology, 108(8), 695–708.
Abstract: Neocortex size has been shown to correlate with group size in primates. Data for carnivores and insectivores are used to test the generality of this relationship. The data suggest that carnivores lie on the same grade as the primates, but that insectivores lie on a separate grade to the left of these two orders. Among the insectivores, there appears to be a distinction between the 'advanced' genera (which show a relationship between group size and neocortex size) and the 'basal' genera (which do not).
|
|
Clayton, N. S., & Dickinson, A. (1998). Episodic-like memory during cache recovery by scrub jays. Nature, 395(6699), 272–274.
Abstract: The recollection of past experiences allows us to recall what a particular event was, and where and when it occurred1,2, a form of memory that is thought to be unique to humans3. It is known, however, that food-storing birds remember the spatial location4, 5, 6 and contents6, 7, 8, 9 of their caches. Furthermore, food-storing animals adapt their caching and recovery strategies to the perishability of food stores10, 11, 12, 13, which suggests that they are sensitive to temporal factors. Here we show that scrub jays (Aphelocoma coerulescens) remember 'when' food items are stored by allowing them to recover perishable 'wax worms' (wax-moth larvae) and non-perishable peanuts which they had previously cached in visuospatially distinct sites. Jays searched preferentially for fresh wax worms, their favoured food, when allowed to recover them shortly after caching. However, they rapidly learned to avoid searching for worms after a longer interval during which the worms had decayed. The recovery preference of jays demonstrates memory of where and when particular food items were cached, thereby fulfilling the behavioural criteria for episodic-like memory in non-human animals.
|
|
Connor, R. C., Mann, J., Tyack, P. L., & Whitehead, H. (1998). Social evolution in toothed whales. Trends. Ecol. Evol, 13(6), 228–232.
Abstract: Two contrasting results emerge from comparisons of the social systems of several odontocetes with terrestrial mammals. Researchers have identified remarkable convergence in prominent features of the social systems of odontocetes such as the sperm whale and bottlenose dolphin with a few well-known terrestrial mammals such as the elephant and chimpanzee. In contrast, studies on killer whales and Baird's beaked whale reveal novel social solutions to aquatic living. The combination of convergent and novel features in odontocete social systems promise a more general understanding of the ecological determinants of social systems in both terrestrial and aquatic habitats, as well as the relationship between relative brain size and social evolution.
|