Home | [1–10] << 11 12 13 14 15 16 17 18 19 20 >> [21–30] |
Branchi, I., Bichler, Z., Berger-Sweeney, J., & Ricceri, L. (2003). Animal models of mental retardation: from gene to cognitive function. Neurosci Biobehav Rev, 27(1-2), 141–153.
Abstract: About 2-3% of all children are affected by mental retardation, and genetic conditions rank among the leading causes of mental retardation. Alterations in the information encoded by genes that regulate critical steps of brain development can disrupt the normal course of development, and have profound consequences on mental processes. Genetically modified mouse models have helped to elucidate the contribution of specific gene alterations and gene-environment interactions to the phenotype of several forms of mental retardation. Mouse models of several neurodevelopmental pathologies, such as Down and Rett syndromes and X-linked forms of mental retardation, have been developed. Because behavior is the ultimate output of brain, behavioral phenotyping of these models provides functional information that may not be detectable using molecular, cellular or histological evaluations. In particular, the study of ontogeny of behavior is recommended in mouse models of disorders having a developmental onset. Identifying the role of specific genes in neuropathologies provides a framework in which to understand key stages of human brain development, and provides a target for potential therapeutic intervention.
Keywords: Animals; Animals, Genetically Modified/growth & development; Behavior/physiology; Behavior, Animal; Brain/*growth & development; Cognition/*physiology; *Disease Models, Animal; Environment; Genes; Genetic Diseases, Inborn/physiopathology; Humans; Mental Retardation/classification/*genetics/*physiopathology
|
Tommasi, L., & Vallortigara, G. (2000). Searching for the center: spatial cognition in the domestic chick (Gallus gallus). J Exp Psychol Anim Behav Process, 26(4), 477–486.
Abstract: Chicks learned to find food hidden under sawdust by ground-scratching in the central position of the floor of a closed arena. When tested inan arena of identical shape but a larger area, chicks searched at 2 different locations, one corresponding to the correct distance (i.e., center) in the smaller (training) arena and the other to the actual center of the test arena. When tested in an arena of the same shape but a smaller area, chicks searched in the center of it. These results suggest that chicks are able to encode information on the absolute and relative distance of the food from the walls of the arena. After training in the presence of a landmark located at the center of the arena, animals searched at the center even after the removal of the landmark. Marked changes in the height of the walls of the arena produced some displacement in searching behavior, suggesting that chicks used the angular size of the walls to estimate distances.
|
Brannon, E. M., & Terrace, H. S. (2000). Representation of the numerosities 1-9 by rhesus macaques (Macaca mulatta). J Exp Psychol Anim Behav Process, 26(1), 31–49.
Abstract: Three rhesus monkeys (Macaca mulatta) were trained to respond to exemplars of 1, 2, 3, and 4 in an ascending, descending, or a nonmonotonic numerical order (1-->2-->3-->4, 4-->3-->2--1, 3-->1-->4-->2). The monkeys were then tested on their ability to order pairs of the novel numerosities 5-9. In Experiment 1, all 3 monkeys ordered novel exemplars of the numerosities 1-4 in ascending or descending order. The attempt to train a nonmonotonic order (3-->1-->4-->2) failed. In Experiment 2A, the 2 monkeys who learned the ascending numerical rule ordered pairs of the novel numerosities 5-9 on unreinforced trials. The monkey who learned the descending numerical rule failed to extrapolate the descending rule to new numerosities. In Experiment 2B all 3 monkeys ordered novel exemplars of pairs of the numerosities 5-9. Accuracy and latency of responding revealed distance and magnitude effects analogous to previous findings with human participants (R. S. Moyer & T. K. Landaeur, 1967). Collectively these studies show that monkeys represent the numerosities 1-9 on at least an ordinal scale.
Keywords: Animals; *Cognition; Macaca mulatta/*psychology; *Mathematics; Perception; Reaction Time
|
Milgram, N. W., Head, E., Muggenburg, B., Holowachuk, D., Murphey, H., Estrada, J., et al. (2002). Landmark discrimination learning in the dog: effects of age, an antioxidant fortified food, and cognitive strategy. Neurosci Biobehav Rev, 26(6), 679–695.
Abstract: The landmark discrimination learning test can be used to assess the ability to utilize allocentric spatial information to locate targets. The present experiments examined the role of various factors on performance of a landmark discrimination learning task in beagle dogs. Experiments 1 and 2 looked at the effects of age and food composition. Experiments 3 and 4 were aimed at characterizing the cognitive strategies used in performance on this task and in long-term retention. Cognitively equivalent groups of old and young dogs were placed into either a test group maintained on food enriched with a broad-spectrum of antioxidants and mitochondrial cofactors, or a control group maintained on a complete and balanced food formulated for adult dogs. Following a wash-in period, the dogs were tested on a series of problems, in which reward was obtained when the animal responded selectively to the object closest to a thin wooden block, which served as a landmark. In Experiment 1, dogs were first trained to respond to a landmark placed directly on top of coaster, landmark 0 (L0). In the next phase of testing, the landmark was moved at successively greater distances (1, 4 or 10 cm) away from the reward object. Learning varied as a function of age group, food group, and task. The young dogs learned all of the tasks more quickly than the old dogs. The aged dogs on the enriched food learned L0 significantly more rapidly than aged dogs on control food. A higher proportion of dogs on the enriched food learned the task, when the distance was increased to 1cm. Experiment 2 showed that accuracy decreased with increased distance between the reward object and landmark, and this effect was greater in old animals. Experiment 3 showed stability of performance, despite using a novel landmark, and new locations, indicating that dogs learned the landmark concept. Experiment 4 found age impaired long-term retention of the landmark task. These results indicate that allocentric spatial learning is impaired in an age-dependent manner in dogs, and that age also affects performance when the distance between the landmark and target is increased. In addition, these results both support a role of oxidative damage in the development of age-associated cognitive dysfunction and indicate that short-term administration of a food enriched with supplemental antioxidants and mitochondrial cofactors can partially reverse the deleterious effects of aging on cognition.
Keywords: Age Factors; Aging/*physiology; Analysis of Variance; Animals; Antioxidants/*pharmacology; Blood Chemical Analysis/methods; Cognition/*physiology; *Diet; Discrimination Learning/*drug effects/*physiology; Distance Perception/drug effects/physiology; Dogs/physiology; Female; Male; Psychomotor Performance/physiology; Retention (Psychology)/drug effects/physiology; Spatial Behavior/*drug effects/*physiology; Task Performance and Analysis; Time Factors; Vitamin E/blood
|
Cowell, P. E., Fitch, R. H., & Denenberg, V. H. (1999). Laterality in animals: relevance to schizophrenia. Schizophr Bull, 25(1), 41–62.
Abstract: Anomalies in the laterality of numerous neurocognitive dimensions associated with schizophrenia have been documented, but their role in the etiology and early development of the disorder remain unclear. In the study of normative neurobehavioral organization, animal models have shed much light on the mechanisms underlying and the factors affecting adult patterns of both functional and structural asymmetry. Nonhuman species have more recently been used to investigate the environmental, genetic, and neuroendocrine factors associated with developmental language disorders in humans. We propose that the animal models used to study the basis of lateralization in normative development and language disorders such as dyslexia could be modified to investigate lateralized phenomena in schizophrenia.
|
Urcuioli, P. J., DeMarse, T. B., & Zentall, T. R. (1998). Transfer across delayed discriminations: II. Differences in the substitutability of initial versus test stimuli. J Exp Psychol Anim Behav Process, 24(1), 47–59.
Abstract: In 2 experiments, pigeons were trained on, and then transferred to, delayed simple discriminations in which the initial stimuli signalled reinforcement versus extinction following a retention interval. Experiment 1 showed that discriminative responding on the retention test transferred to novel test stimuli that had appeared in another delayed simple discrimination but not to stimuli having the same reinforcement history off-baseline. By contrast, Experiment 2 showed that performances transferred to novel initial stimuli whether they had been trained on-baseline or off-baseline. These results suggest that the test stimuli in delayed simple discriminations acquire control over responding only in the memory task itself. On the other hand, control by the initial stimuli, if coded as outcome expectancies, does not require such task-specific training.
|
Brodbeck, D. R. (1997). Picture fragment completion: priming in the pigeon. J Exp Psychol Anim Behav Process, 23(4), 461–468.
Abstract: It has been suggested that the system behind implicit memory in humans is evolutionarily old and that animals should readily show priming. In Experiment 1, a picture fragment completion test was used to test priming in pigeons. After pecking a warning stimulus, pigeons were shown 2 partially obscured pictures from different categories and were always reinforced for choosing a picture from one of the categories. On control trials, the warning stimulus was a picture of some object (not from the S+ or S- category), on study trials the warning stimulus was a picture to be categorized on the next trial, and on test trials the warning stimulus was a randomly chosen picture and the S+ picture was the warning stimulus seen on the previous trial. Categorization was better on study and test trials than on control trials. Experiment 2 ruled out the possibility that the priming effect was caused by the pigeons' responding to familiarity by using warning stimuli from both S+ and S- categories. Experiment 3 investigated the time course of the priming effect.
|
Church, R. M. (1997). Quantitative models of animal learning and cognition. J Exp Psychol Anim Behav Process, 23(4), 379–389.
Abstract: This article reviews the prerequisites for quantitative models of animal learning and cognition, describes the types of models, provides a rationale for the development of such quantitative models, describes criteria for their evaluation, and makes recommendations for the next generation of quantitative models. A modular approach to the development of models is described in which a procedure is considered as a generator of stimuli and a model is considered as a generator of responses. The goal is to develop models that, in combination with many different procedures, produce sequences of times of occurrence of events (stimuli and responses) that are indistinguishable from those produced by the animal under many experimental procedures and data analysis techniques.
|
Wasserman, E. A. (1997). The science of animal cognition: past, present, and future. J Exp Psychol Anim Behav Process, 23(2), 123–135.
Abstract: The field of animal cognition is strongly rooted in the philosophy of mind and in the theory of evolution. Despite these strong roots, work during the most famous and active period in the history of our science-the 1930s, 1940s, and 1950s-may have diverted us from the very questions that were of greatest initial interest to the comparative analysis of learning and behavior. Subsequently, the field has been in steady decline despite its increasing breadth and sophistication. Renewal of the field of animal cognition may require a return to the original questions of animal communication and intelligence using the most advanced tools of modern psychological science. Reclaiming center stage in contemporary psychology will be difficult; planning that effort with a host of strategies should enhance the chances of success.
|
Wasserman, E. A., Gagliardi, J. L., Cook, B. R., Kirkpatrick-Steger, K., Astley, S. L., & Biederman, I. (1996). The pigeon's recognition of drawings of depth-rotated stimuli. J Exp Psychol Anim Behav Process, 22(2), 205–221.
Abstract: Four experiments used a four-choice discrimination learning paradigm to explore the pigeon's recognition of line drawings of four objects (an airplane, a chair, a desk lamp, and a flashlight) that were rotated in depth. The pigeons reliably generalized discriminative responding to pictorial stimuli over all untrained depth rotations, despite the bird's having been trained at only a single depth orientation. These generalization gradients closely resembled those found in prior research that used other stimulus dimensions. Increasing the number of different vantage points in the training set from one to three broadened the range of generalized testing performance, with wider spacing of the training orientations more effectively broadening generalized responding. Template and geon theories of visual recognition are applied to these empirical results.
|