780 resultados para multi-objective decision making
Resumo:
Inspired by research in the field of behavioral economics as well as social psychology, this study aimed to explore if conformity plays a role in the occurrence of herd behavior in the financial market. Participants received one of nine different versions of a survey either online or on paper. They answered questions related to riskiness when making decisions, dependency on others when making decisions, and investment preferences among other questions. In experimental conditions, participants were told the majority of investors, either sixty percent or eighty percent, invested in a certain stock or won a game. It was predicted that individuals would conform to the group behavior in both experimental conditions with the highest level of conformity in the high pressure to conform condition. Results of experiments revealed that when the overwhelming majority of other investors behaved a certain way (80%), participants were more likely to behave that same way. Results of the third experiment supported previous research stating that emotion affects economic decision-making and facilitates herd behavior.
Resumo:
Recent legislative and regulatory developments have focused attention on older adults' capacity for involvement in health care decision-making. The Omnibus Budget Reconciliation Act of 1987 (OBRA 87) focused attention on the rights of nursing home residents to be involved in health care decision-making to the fullest extent possible. This article uses data from the 1987 National Medical Expenditure Survey (NMES) to examine rates of incapacity for health care decision-making among nursing home residents. Elements of the Oklahoma statute were used to operationalize decision-making incapacity: disability or disorder, difficulty in decision-making or communicating decisions, and functional disability. Fifty-three percent of nursing home residents had a combination of either physical or mental impairment and an impairment in either self-care or money management. The discussion focuses on the policy and practice implications of significant rates of incapacity among nursing home residents.
Resumo:
BACKGROUND: Systematic need for angiography in diagnosis of carotid artery stenosis and indication of surgical therapy is still debated. Noninvasive imaging techniques such as MR angiography (MRA) or CT angiography (CTA) offer an alternative to digital subtraction angiography (DSA) and are increasingly used in clinical practice. In this study, we present the radiological characteristics and clinical results of a series of patients operated on the basis of combined ultrasonography (US)/MRA. METHODS: This observational study included all the patients consecutively operated for a carotid stenosis in our Department from October 1998 to December 2004. The applied MRA protocol had previously been established in a large correlation study with DSA. DSA was used only in case of discordance between US and MRA. The preoperative radiological information furnished by MRA was compared with intraoperative findings. The outcome of the operation was assessed according to ECST criteria. RESULTS: Among 327 patients, preoperative MRA was performed in 278 (85%), DSA in 44 (13.5%) and CT angiography in 5 (1.5%). Most of DSA studies were performed as emergency for preparation of endovascular therapy or for reasons other than carotid stenosis. Eleven additional DSA (3.3%) complemented US/MRA, mostly because diverging diagnosis of subocclusion of ICA. No direct morbidity or intraoperative difficulty was related to preoperative MRA. Combined mortality/major morbidity rate was 0.9% (3 patients) and minor morbidity rate 5.5% (18 patients). CONCLUSIONS: This observational study describes a well-established practice of carotid surgery and supports the exclusive use of non invasive diagnostic imaging for indicating and deciding the operation.
Resumo:
Previous work has reported that in the Iowa gambling task (IGT) advantageous decisions may be taken before the advantageous strategy is known [Bechara, A., Damasio, H., Tranel, D., ; Damasio, A. R. (1997). Deciding advantageously before knowing the advantageous strategy. Science, 275, 1293-1295]. In order to test whether explicit memory is essential for the acquisition of a behavioural preference for advantageous choices, we measured behavioural performance and skin conductance responses (SCRs) in five patients with dense amnesia following damage to the basal forebrain and orbitofrontal cortex, six amnesic patients with damage to the medial temporal lobe or the diencephalon, and eight control subjects performing the IGT. Across 100 trials healthy participants acquired a preference for advantageous choices and generated large SCRs to high levels of punishment. In addition, their anticipatory SCRs to disadvantageous choices were larger than to advantageous choices. However, this dissociation occurred much later than the behavioural preference for advantageous alternatives. In contrast, though exhibiting discriminatory autonomic SCRs to different levels of punishment, 9 of 11 amnesic patients performed at chance and did not show differential anticipatory SCRs to advantageous and disadvantageous choices. Further, the magnitude of anticipatory SCRs did not correlate with behavioural performance. These results suggest that the acquisition of a behavioural preference--be it for advantageous or disadvantageous choices--depends on the memory of previous reinforcements encountered in the task, a capacity requiring intact explicit memory.