The basis of informed consent for BMT patients. (1/612)

During recent decades the doctrine of informed consent has become a standard part of medical care as an expression of patients' rights to self-determination. In situations when only one treatment alternative exists for a potential cure, the extent of a patient's self-determination is constrained. Our hypothesis is that for patients considering a life-saving procedure such as bone marrow transplant (BMT), informed consent has little meaning as a basis for their right to self-determination. A longitudinal study of BMT patients was undertaken with four self-administered questionnaires. Questions centered around expectations, knowledge, anxiety and factors contributing to their decision to undergo treatment. Although the informed consent process made patients more knowledgeable about the treatment, their decision to consent was largely based on positive outcome expectations and on trust in the physician. Informed consent relieved their anxieties and increased their hopes for survival. Our conclusion was that the greatest value of the informed consent process lay in meeting the patients' emotional rather than cognitive needs. When their survival is at stake and BMT represents their only option, the patient's vulnerability puts a moral responsibility on the physician to respect the principle of beneficence while not sacrificing the patient's right to self-determination.  (+info)

"What" and "how": evidence for the dissociation of object knowledge and mechanical problem-solving skills in the human brain. (2/612)

Patients with profound semantic deterioration resulting from temporal lobe atrophy have been reported to use many real objects appropriately. Does this preserved ability reflect (i) a separate component of the conceptual knowledge system ("action semantics") or (ii) the operation of a system that is independent of conceptual knowledge of specific objects, and rather is responsible for general mechanical problem-solving skills, triggered by object affordances? We contrast the performance of three patients-two with semantic dementia and focal temporal lobe atrophy and the third with corticobasal degeneration and biparietal atrophy-on tests of real object identification and usage, picture-based tests of functional semantic knowledge, and a task requiring selection and use of novel tools. The patient with corticobasal degeneration showed poor novel tool selection and impaired use of real objects, despite near normal semantic knowledge of the same objects' functions. The patients with semantic dementia had the expected deficit in object identification and functional semantics, but achieved flawless and effortless performance on the novel tool task. Their attempts to use this same mechanical problem-solving ability to deduce (sometimes successfully but often incorrectly) the use of the real objects provide no support for the hypothesis of a separate action-semantic system. Although the temporal lobe system clearly is necessary to identify "what" an object is, we suggest that sensory inputs to a parietal "how" system can trigger the use of objects without reference to object-specific conceptual knowledge.  (+info)

The functional neuroanatomy of comprehension and memory: the importance of prior knowledge. (3/612)

Stories are a common way in which humans convey and acquire new information. Their effectiveness and memorability require that they be understood which, in turn, depends on two factors-whether the story makes sense and the prior knowledge that the listener brings to bear. Comprehension requires the linking of related pieces of information, some provided within the story and some by the listener, in a process establishing coherence. In this study, we examined brain activations associated with story processing. During PET scanning, passages of prose were read twice to subjects during successive scans with the requirement to remember them. These were either standard stories that were readily comprehensible, or unusual stories for which the global theme was very difficult to extract without prior knowledge of the mental framework. This was manipulated by the provision of relevant, irrelevant or no visual cues shortly before the story. Ratings of comprehension provided by the subjects just after each scan confirmed that standard stories were more comprehensible than the unusual stories, as were unusual stories with a mental framework compared with those without. PET results showed activation of anterior and ventral parts of the medial parietal/posterior cingulate cortex in association with hearing unusual stories when subjects were given prior knowledge of what it might be about. Medial ventral orbitofrontal cortex and left temporal pole activations were found to be associated with more general aspects of comprehension. Medial parietal cortex (precuneus) and left prefrontal cortex were associated with story repetition. We suggest that while the temporal pole is involved in the linking of propositions to build a narrative, the anterior medial parietal/posterior cingulate cortex is concerned with linking this information with prior knowledge. All of this occurs in the context of a general memory processing/retrieval system that includes the posterior parietal (precuneus) and prefrontal cortex. Knowledge of how distinct brain regions contribute differentially to aspects of comprehension and memory has implications for understanding how these processes break down in conditions of brain injury or disease.  (+info)

Circular epidemiology. (4/612)

Circular epidemiology can be defined as the continuation of specific types of epidemiologic studies beyond the point of reasonable doubt of the true existence of an important association or the absence of such an association. Circular epidemiology is an extreme example of studies of the consistency of associations. A basic problem for epidemiology is the lack of a systematic approach to acquiring new knowledge to reach a goal of improving public health and preventive medicine. For epidemiologists, research support unfortunately is biased toward the continued study of already proven hypotheses. Circular epidemiology, however, freezes at one point in the evolution of epidemiologic studies, failing to move from descriptive to analytical case-control and longitudinal studies, for example, to experimental, clinical trials. Good epidemiology journals are filled with very well-conducted epidemiologic studies that primarily repeat the obvious or are variations on the theme.  (+info)

Information technology and knowledge exchange in health-care organizations. (5/612)

Despite the increasing global interest in information technology among health care institutions, little has been discussed about its importance for the effectiveness of knowledge management. In this study, economic theories are used to analyze and describe a theoretical framework for the use of information technology in the exchange of knowledge. The analyses show that health care institutions would benefit from developing global problem-solving collaboration, which allows practitioners to exchange knowledge unrestricted by time and geographical barriers. The use of information technology for vertical integration of health-care institutions would reduce knowledge transaction costs, i.e. decrease costs for negotiating and creating communication channels, and facilitating the determination of what, when, and how to produce knowledge. A global network would allow organizations to increase existing knowledge, and thus total productivity, while also supporting an environment where the generation of new ideas is unrestricted. Using all the intellectual potential of market actors and thereby releasing economic resources can reduce today's global budget conflicts in the public sector, i.e. the necessity to choose between health care services and, for instance, schools and support for the elderly. In conclusion, global collaboration and coordination would reduce the transaction costs inherent in knowledge administration and allow a more effective total use of scarce health-care resources.  (+info)

Topographical knowledge survives hippocampal damage. (6/612)

Study of a patient with damage to the hippocampus and surrounding neocortex reveals intact topographical knowledge of his childhood environment. New studies of spatial memory in animals are also giving insight into the process by which spatial memory becomes consolidated over time.  (+info)

Power and the teaching of medical ethics. (7/612)

This paper argues that ethics education needs to become more reflective about its social and political ethic as it participates in the construction and transmission of medical ethics. It argues for a critical approach to medical ethics and explores the political context in medical schools and some of the peculiar problems in medical ethics education.  (+info)

Splendours and miseries of the brain. (8/612)

In this speculative essay, I examine two evolutionary developments underlying the enormous success of the human brain: its capacity to acquire knowledge and its variability across individuals. A feature of an efficient knowledge-acquiring system is, I believe, its capacity to abstract and to formulate ideals. Both attributes carry with them a clash between experience of the particular and what the brain has developed from experience of the many. Both therefore can lead to much disappointment in our daily lives. This disappointment is heightened by the fact that both abstraction and ideals are subject to variability in time within an individual and between individuals. Variability, which is a cherished source for evolutionary selection, can also be an isolating and individualizing feature in society. Thus the very features of the human brain which underlie our enormous evolutionary success can also be a major source of our misery.  (+info)