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941.
Response-independent Events In The Behavior Stream   总被引:2,自引:2,他引:0       下载免费PDF全文
The metaphor of the behavior stream provides a framework for studying the effects of response-independent food presentations intruded into an environment in which operant responding of pigeons was maintained by variable-interval schedules. In the first two experiments, response rates were reduced when response-independent food was intruded during the variable-interval schedule according to a concomitantly present fixed-time schedule. These reductions were not always an orderly function of the percentage of response-dependent food. Negatively accelerated patterns of key pecking across the fixed-time period occurred in Experiment 1 under the concomitant fixed-time variable-interval schedules. In Experiment 2, positively and negatively accelerated and linear response patterns occurred even though the schedules were similar to those used in Experiment 1. The variable findings in the first two experiments led to three subsequent experiments that were designed to further illuminate the controlling variables of the effects of intruded response-independent events. When the fixed and variable schedules were correlated with distinct operanda by employing a concurrent fixed-interval variable-interval schedule (Experiment 3) or with distinct discriminative stimuli (Experiments 4 and 5), negatively accelerated response patterns were obtained. Even in these latter cases, however, the response patterns were a joint function of the physical separation of the two schedules and the ratio of fixed-time or fixed-interval to variable-interval schedule food presentations. The results of the five experiments are discussed in terms of the contributions of both reinforcement variables and discriminative stimuli in determining the effects of intruding response-independent food into a stream of operant behavior.  相似文献   
942.
In the area of child psychosocial intervention research, substantial progress in addressing challenging methodological issues has been made. In this article we suggest that continued movement forward requires maintaining a balance between methodological and theoretical issues, and that it would be advantageous to begin to think about matching advances in methodological sophistication by similar advances in theoretical sophistication. The need to advance our understanding of theoretical issues is especially important in light of the challenges raised by postmodernism, particularly as these challenges relate to knowledge development. We discuss these challenges and describe how a pragmatic orientation may be a useful way to respond to them. We also describe how a pragmatic orientation has been useful in our work in developing, implementing and evaluating psychosocial interventions for children with phobic and anxiety disorders.  相似文献   
943.
The ability to compensate for fixation of the jaw by a bite block was investigated in 6 nonfluent aphasics, 6 fluent aphasics, and 10 normal control subjects. Acoustic analyses of the vowels [i u a æ] and fricatives [s s] revealed substantial but incomplete compensation for the perturbation in all three subject groups. Perceptual identification scores and quality ratings by naive and phonetically trained listeners indicated poorer identification of the high vowels [i u] under compensatory conditions relative to normal production. Of particular interest was the fact that all three groups of subjects exhibited similar patterns of results. The findings suggest that any deficit in speech motor programming demonstrated by the nonfluent aphasic patients did not affect compensatory abilities. Results are discussed with respect to normal speech adaptation skills and the nature of articulatory breakdown in nonfluent aphasia.  相似文献   
944.
This issue, redesigned in a new format, marks the beginning of Volume 25, the beginning of the silver anniversary year of the Journal of Abnormal Child Psychology. Data were compiled from the first 24 volumes to study changes over time, and Pearson correlations were calculated to determine linear trends in the journal's development The number of articles per volume has doubled, from about 25 to 50. In recent years the first authors of articles were more likely to be located outside the U.S. (up from about 5% to about 25%). Also, in recent years the first authors of articles were less likely to be affiliated with nonmedical school university departments and more likely to be affiliated with medical schools or research institutes. An introduction to this special 25th anniversary issue is provided.  相似文献   
945.
Tested a theoretical model on the effects of social role identity, illness intrusion, and competence on psychological well-being among 109 low-income Latinas with arthritis. All six roles studied were rated as highly important identities. Sex-role nontraditionalism was associated with less importance of the homemaker, mother, and grandmother roles. Negative affect increased as a function of intrusions into valued identities. Having important role identities contributed to feelings of competence (i.e., self-esteem and self-efficacy), which in turn, contributed to psychological well-being. Competence also mediated the effects of pain, identity, and illness intrusions on psychological well-being. Results suggest competence processes play an important role in well-being.  相似文献   
946.
Immunoreactivity of the immediate early gene c-fos was used to investigate changes in the activity of brainstem neurons in response to acute stressors like immobilization, formalin-induced pain, cold exposure, hemorrhage and insulin-induced hypoglycemia. Different stressors induced Fos-like immunoreactivity in different pontine and medullary neurons. A single, 3 hour immobilization was found to be a very strong stimulus that activated brainstem catecholaminergic (tyrosine hydroxylase-immunopositive) neurons and cells in the raphe and certain pontine tegmental nuclei, as well as in the reticular formation. Pain, induced by a subcutaneous injection of formalin was also effective on catecholamine-synthesizing neurons and on others cells in the nucleus of the solitary tract. Cold exposure activated cells mainly in the sensory spinal trigeminal and parabrachial nuclei and in the so-called "pontine thermoregulatory area". Moderate Fos-like immunoreactivity was induced by a hypotonic (25%) hemorrhage in medullary catecholaminergic neurons, the nucleus of the solitary tract and the Barrington nucleus. Among stressful stimuli used, insulin-induced hypoglycemia elicited the smallest Fos activation in the lower brainstem. The present observations indicate that different stressors may use different neuronal pathways in the central organization of the stress response.  相似文献   
947.
The Convention on Human Rights and Biomedicine developed by the Council of Europe, now undergoing ratification, is the first international treaty focused on bioethics. This article describes the background of the Convention's development and its general provisions and provides a comparison of its requirements with those of federal regulations governing research with human subjects. Although most provisions are comparable, there are significant differences in scope and applicability, for example, in the areas of compensation for injury, research participation by persons with limited capacity to consent, assisted reproduction, organ transplantation, and research in emergency situations. The Convention represents a milestone in international bioethics and protection of human rights that will probably be referred to with increasing frequency.  相似文献   
948.
Managed care organizations can produce conflicts of obligation and conflicts of interest that may lead to problems of conscience for health care professionals. This paper provides a basis for understanding the notions of conscience and conscientious objection and offers a framework for clinicians to stake out positions grounded in personal conscience as a way for them to respond to unacceptable pressures from managers to limit services.  相似文献   
949.
Automated aids and decision support tools are rapidly becoming indispensable tools in high-technology cockpits and are assuming increasing control of"cognitive" flight tasks, such as calculating fuel-efficient routes, navigating, or detecting and diagnosing system malfunctions and abnormalities. This study was designed to investigate automation bias, a recently documented factor in the use of automated aids and decision support systems. The term refers to omission and commission errors resulting from the use of automated cues as a heuristic replacement for vigilant information seeking and processing. Glass-cockpit pilots flew flight scenarios involving automation events or opportunities for automation-related omission and commission errors. Although experimentally manipulated accountability demands did not significantly impact performance, post hoc analyses revealed that those pilots who reported an internalized perception of "accountability" for their performance and strategies of interaction with the automation were significantly more likely to double-check automated functioning against other cues and less likely to commit errors than those who did not share this perception. Pilots were also lilkely to erroneously "remember" the presence of expected cues when describing their decision-making processes.  相似文献   
950.
The focus of this paper is mechanisms that may be responsible for intellectual and developmental differences in the cognitive strategies of typical and atypical children, including those with mental retardation. The discussion of these mechanisms is based on behavioral experiments on external memory strategies and on a set of neural network models designed for these tasks. Following the review of the external memory research, the rationale for using neural network models, how they have been used in other research, and their specific application to intellectual and developmental differences in external memory, including the results of several simulations, are reviewed. This is followed by a discussion of the mechanisms of intellectual differences and developmental change included in the models and some challenges for this type of modeling. Neural network modeling is discussed as an asset to research on cognitive development.  相似文献   
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