| Home | << 1 2 3 4 5 6 7 8 9 10 >> [11–14] |
|
Sutton J.E., & Roberts W.A. (1998). Do pigeons show incidental timing? Some experiments and a suggested hierarchical framework for the study of attention in animal cognition. Behav. Process., 44, 263–275.
|
|
Byrne, T., Sutphin, G., & Poling, A. (1998). Acquisition, extinction, and reacquisition of responding with delayed and immediate reinforcement. Behav. Process., 43(1), 97–101.
Abstract: The present study investigated acquisition, extinction, and reacquisition of free-operant responding when rats' lever presses produced water after a resetting delay of 0, 10, 20, or 30 s. Results indicated that: (1) responding was acquired rapidly at all delays without shaping or autoshaping; (2) resistance to extinction was directly related to delay length and inversely related to intermittency of reinforcement; (3) responding acquired with delayed reinforcement recovered less rapidly from extinction, and was less efficient, than responding acquired with immediate reinforcement. Comparing these results with those of studies using discrete-trials and free-operant procedures with no reinforcement delay suggest that the specific conditions under which behavior is maintained determines, in part, the behavioral effects of delay and intermittency of reinforcement.
Keywords: Acquisition; Delayed reinforcement; Extinction; Rats
|
|
Duncan, I. J. H., Widowski, T. M., Malleau, A. E., Lindberg, A. C., & Petherick, J. C. (1998). External factors and causation of dustbathing in domestic hens. Behav. Process., 43(2), 219–228.
Abstract: Dustbathing is known to be motivated by complex interactions between internal factors which build up over time and external factors, such as the sight of a dusty substrate. In this study, the effects of other external factors were investigated. Environmental temperature was shown to be important; frequencies of dustbathing were greater when hens were held at 22 than at 10[degree sign]C (P<0.01). In a second experiment, a radiant heat source or a radiant heat+light source, balanced to give the same radiant heat, resulted in more dustbathing behaviour during a 1-h stimulus period than during the same period with no stimulus (P<0.05). Components of dustbathing were increased more by the heat+light stimulus than by the heat stimulus alone (P<0.03). In a third experiment, the amount of dustbathing performed by individual hens in cages with dustbaths was increased by the presence of a group of hens dustbathing in an adjoining pen with a dustbath compared with the amount occurring when the hens were absent from the pen.
Keywords: Dustbathing; Illumination; Laying hens; Radiant heat; Social facilitation; Temperature
|
|
Carpenter, M., Nagell, K., Tomasello, M., Butterworth, G., & Moore, C. (1998). Social Cognition, Joint Attention, and Communicative Competence from 9 to 15 Months of Age. Monogr Soc Res Child Dev, 63(4), 1–174.
Abstract: At around 1 year of age, human infants display a number of new behaviors that seem to indicate a newly emerging understanding of other persons as intentional beings whose attention to outside objects may be shared, followed into, and directed in various ways. These behaviors have mostly been studied separately. In the current study, we investigated the most important of these behaviors together as they emerged in a single group of 24 infants between 9 and 15 months of age. At each of seven monthly visits, we measured joint attentional engagement, gaze and point following, imitation of two different kinds of actions on objects, imperative and declarative gestures, and comprehension and production of language. We also measured several nonsocial-cognitive skills as a point of comparison. We report two studies. The focus of the first study was the initial emergence of infants' social-cognitive skills and how these skills are related to one another developmentally. We found a reliable pattern of emergence: Infants progressed from sharing to following to directing others' attention and behavior. The nonsocial skills did not emerge predictably in this developmental sequence. Furthermore, correlational analyses showed that the ages of emergence of all pairs of the social-cognitive skills or their components were interrelated. The focus of the second study was the social interaction of infants and their mothers, especially with regard to their skills of joint attentional engagement (including mothers' use of language to follow into or direct infants' attention) and how these skills related to infants' early communicative competence. Our measures of communicative competence included not only language production, as in previous studies, but also language comprehension and gesture production. It was found that two measures-the amount of time infants spent in joint engagement with their mothers and the degree to which mothers used language that followed into their infant's focus of attention-predicted infants' earliest skills of gestural and linguistic communication. Results of the two studies are discussed in terms of their implications for theories of social-cognitive development, for theories of language development, and for theories of the process by means of which human children become fully participating members of the cultural activities and processes into which they are born.
|
|
Pavey, C. R., & Smyth, A. K. (1998). Effects of avian mobbing on roost use and diet of powerful owls,Ninox strenua. Anim. Behav., 55(2), 313–318.
Abstract: We observed the species and numbers of mobbing birds and their effects on a large, nocturnal, bird-eating predator, the powerful owl, together with the pattern of owl predation on mobbing and non-mobbing species. Owls were mobbed on 35 occasions by seven of 44 species of forest birds at a site composed of open forest (88% by area) and rainforest (12%). The majority of bouts involved individuals of a single species, although mixed groups were observed on nine occasions. Regular mobbers were between 4 and 26% of the owls' body weight. Owls abandoned their daytime roosts during 20% of bouts and responded by calling or actively monitoring mobbers during 54% of bouts. Mobbing appeared to explain why owls roosted in rainforest significantly more often than expected by its availability, mobbing being significantly less frequent in rainforest than in open forest. Only one mobbing species regularly occupied rainforest and the canopy of roosts in rainforest was denser than that in open forest, thus reducing the chances of an owl being detected by potential mobbers. Twelve species of forest birds were within the range of prey size of the powerful owl (75-800 g): six were mobbers and six non-mobbers. The frequency of owl predation on non-mobbers was 8.75 times that on mobbers. The species in this study took a high risk by mobbing a very large predator, but benefited by greatly reducing their chances of predation.
|
|
Kamil, A. C. (1998). On the Proper Definition of Cognitive Ethology. In Russell P. Balda, Irene M. Pepperberg, & Alan C. Kamil (Eds.), Animal Cognition in Nature (pp. 1–28). London: Academic Press.
Abstract: Summary The last 20-30 years have seen two `scientific revolutions' in the study of animal behavior: the cognitive revolution that originated in psychology, and the Darwinian, behavioral ecology revolution that originated in biology. Among psychologists, the cognitive revolution has had enormous impact. Similarly, among biologists, the Darwinian revolution has had enormous impact. The major theme of this chapter is that these two scientific research programs need to be combined into a single approach, simultaneously cognitive and Darwinian, and that this single approach is most appropriately called cognitive ethology.
|
|
Piggins, D., & Phillips, C. J. C. (1998). Awareness in domesticated animals--concepts and definitions. Appl. Anim. Behav. Sci., 57(3-4), 181–200.
Abstract: Humans will probably never experience the awareness of another species, but adopting a broad concept of awareness leads to the conclusion that other species have some awareness. The existence of a more complex mind in humans, compared with other species, leads some to suggest that awareness only exists in humans. We postulate that humans possess a significantly increased level of awareness, facilitated in particular by the acquisition of language, but that generally animals possess a level of awareness that is appropriate to their needs. Categories of awareness can be devised by identifying levels, such as are used in the identification of the conscious state in humans, or by ranking states of awareness in order of complexity. A scheme is proposed that combines these two approaches, which is considered suitable for use with domesticated animals. The advantages of identifying awareness as being sensation-, perception- or cognition-based are discussed, as well as the possibility of a scheme based on the degree and site of CNS processing. Finally, the acquisition of awareness by learning and inheritance is considered, and it is argued that in variable environments, animals will evolve increased awareness, whereas in very stable environments the energetic cost of awareness will encourage the evolution of less aware animals.
Keywords: Complex mind; Awareness; Humans; Domesticated animals; Conscious state
|
|
Lomas, C. A., Piggins, D., & Phillips, C. J. C. (1998). Visual awareness. Appl. Anim. Behav. Sci., 57(3-4), 247–257.
Abstract: Awareness varies between different species and humans can never truly appreciate what it is like to be another individual, either of the same species or another. Visual perceptual faculties provide some evidence of the extent to which domesticated animals derive information from objects in their environment, whilst changes in behaviour resulting from different visual stimuli can also provide valuable information on the state of visual awareness. Extensive processing of potentially visual information must occur in all domesticated species, but is much less well understood than purely sensory based information. For example, sensory aspects of colour vision are reasonably well understood, but the role of wavelength variables in an animal's cognition and its colour experience is not clear. Considerable use is made of diurnal changes in photoperiod to synchronise endogenous rhythms to particular times of the day and the year. Variation in light intensity in natural images is also important for social reasons for animals to be able to discriminate between, e.g., different faces, but little is known about intensity preferences or the effects of intensity on behaviour. It appears likely that in many cases visual stimuli represent some of the most important influences on an animal's awareness, either alone or in combination with, e.g., olfactory cues. However, a much greater understanding of their processing is required before we can make useful deductions about visual awareness in domesticated animals.
Keywords: Visual awareness; Colour vision; Rhythm
|
|
Veissier, I., Boissy, A., Nowak, R., Orgeur, P., & Poindron, P. (1998). Ontogeny of social awareness in domestic herbivores. Appl. Anim. Behav. Sci., 57(3-4), 233–245.
Abstract: It is now well established that domestic animals construct responses to their environment that depend on experience and on integration of several features of the environment, including social partners. This ability to be aware of the environment is not fully developed at birth but improves and varies through the animal's life. This topic is discussed on the basis of social processes in sheep and cattle. Social relationships of an animal with its conspecifics develop with age; they do not merely depend on pre-programmed behaviours but rely at least in part on learning of characteristics of the partners. Soon after birth, a strong preferential bond establishes with the dam then to a lesser extent, the young associates to other members of the flock, especially other young. The attractiveness of the group varies later in life due to external events or to physiological state: the abrupt separation from the dam at artificial weaning strengthens bonds between peers, whereas around parturition, females are less disturbed by isolation from the group. More recently, the awareness of social partners has been described in non-social contexts: the animal modifies its responses to events according to the presence of partners, and also to their emotional state and behaviour. The effects of partners seem to depend on their relationship with the animal and also on the social motivation of that animal, which both vary during its life. We recommend study of the ontogeny of awareness using the model of social influences.
Keywords: Animal; Environment; Relationship
|
|
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.
|