Recognizing Racit Knowledge in Medical Epistemology

The evidence-based medicine movement advocates basing all medical decisions on certain types of quantitative research data and has stimulated protracted controversy and debate since its inception. Evidence-based medicine presupposes an inaccurate and deficient view of medical knowledge. Michael Polanyi’s theory of tacit knowledge both explains this deficiency and suggests remedies for it. Polanyi shows how all explicit human knowledge depends on a wealth of tacit knowledge which accrues from experience and is essential for problem solving. Edmund Pellegrino’s classic treatment of clinical judgment is examined, and a Polanyian critique of this position demonstrates that tacit knowledge is necessary for understanding how clinical judgment and medical decisions involve persons. An adequate medical epistemology requires much more qualitative research relevant to the clinical encounter and medical decision making than is currently being done. This research is necessary for preventing an uncritical application of evidence-based medicine by health care managers that erodes good clinical practice. Polanyi’s epistemology shows the need for this work and provides the structural core for building an adequate and robust medical epistemology that moves beyond evidence-based medicine.An erratum to this article can be found at     

Consensus effects in categorization decisions

A previous study (Gilat et al., J. Exp. Psychol. Appl. 3 (1997) 83) has shown that the incentive to reach consensus can raise the tendency to rely on base rates in signal detection decisions and can reduce the probability that less likely events will be accurately classified. This phenomenon was named the “consensus effect”. The current study assesses the conditions under which this effect develops and in particular the effects of information about the game and of the incentive structure on the learning process. The results of three experiments show that the learning process slows when participants have information about the actual state of nature. This finding is captured by a reinforcement learning model with the assumption that information narrows the distribution of the initial propensities for choosing among cutoffs. The results are further evidence for the utility of the combination of learning models and analyses of cognitive processes for the prediction of decision making in situations involving multiple players.     

Proof-Theoretic Modal PA-Completeness I: A System-Sequent Metric

This paper is the first of a series of three articles that present the syntactic proof of the PA-completeness of the modal system G, by introducing suitable proof-theoretic objects, which also have an independent interest. We start from the syntactic PA-completeness of modal system GL-LIN, previously obtained in [7], [8], and so we assume to be working on modal sequents S which are GL-LIN-theorems. If S is not a G-theorem we define here a notion of syntactic metric d(S, G): we calculate a canonical characteristic fomula H of S (char(S)) so that _G H (S) and _GL-LIN H, and the complexity of H gives the distance d(S, G) of S from G. Then, in order to produce the whole completeness proof as an induction on this d(S, G), we introduce the tree-interpretation of a modal sequent Q into PA, that sends the letters of Q into PA-formulas describing the properties of a GL-LIN-proof P of Q: It is also a d(*, G)-metric linked interpretation, since it will be applied to a proof-tree T of H with H = char(S) and ( H) = d(S, G).     

In re Edna MF: Case Law Confusion in Surrogate Decision Making

I review the recent case of Edna Folz, a 73 year-old woman who was suffering through the end stages of very advanced Alzheimer's dementia when her case was adjudicated by the Wisconsin Supreme Court. I consider this case as an example of how courts are increasingly misinterpreting the ethical and legal decision-making standards known as substituted judgment and best interests and thereby threatening individuals' treatment decision-making rights as developed by other courts over the past two decades and creating serious roadblocks to health-care providers' ability to render appropriate patient care. The Wisconsin Supreme Court held that Edna's legal guardian could not authorize withdrawal of Edna's treatment, ruling that as a matter of law, if an incompetent person is not in a persistent vegetative state, it is not in his or her best interests for life-sustaining treatment to be withdrawn unless (s)he has executed an advance directive or other statement clearly indicating his or her desires.     

遗忘症患者外显与内隐记忆实验研究:语义性启动效应任务

采用ＷＭＳ—ＣＲ和ＭＭＳＥ对临床脑损伤患者进行了认知功能与记忆功能两方面的筛选,获得９名遗忘症患者。然后采用偏好和自由联想两项语义性启动效应任务进行测验,发现遗忘症患者在外显记忆受损情况下,的确存在语义性启动效应,且与正常对照相近。推论语义性启动效应任务与遗忘患者损伤的颞叶或间脑结构无关。同时还讨论了启动效应任务,认为偏好任务采用言语性材料不是理想的方法。     

Eliminating national stereotypes: Direct versus indirect disconfirmation of beliefs in covariation

Two modes of disconfirmation of national stereotypes were compared. It was hypo-thesized that stereotypes should be revised either by stereotype-inconsistent cases from the primary target (i.e., direct disconfirmation) or by instances which belong to an alternative target but possess features stereotypic of the primary target (indirect disconfirmation). It was further predicted that politically liberal individuals would show greater change in their national stereotypes than conservatives. Two experiments were conducted in which the salience of directly and indirectly disconfirming information regarding different nations was manipulated. The results indicated that indirect disconfirmation generally had as much impact as direct disconfirmation, but that the effects were particularly visible among liberal participants. Conservatives tended to respond in a reactive manner which preserved or exaggerated their original views. A new theoretical framework for the study of stereotype change and implications for its application were discussed.     

Probability: A new logico-semantical approach

This approach does not define a probability measure by syntactical structures. It reveals a link between modal logic and mathematical probability theory. This is shown (1) by adding an operator (and two further connectives and constants) to a system of lower predicate calculus and (2) regarding the models of that extended system. These models are models of the modal systemS ₅ (without the Barcan formula), where a usual probability measure is defined on their set of possible worlds. Mathematical probability models can be seen as models ofS ₅.     

An elicitation method for multiple linear regression models

This paper describes a method of quantifying subjective opinion about a normal linear regression model. Opinion about the regression coefficients and experimental error is elicited and modeled by a multivariate probability distribution (a Bayesian conjugate prior distribution). The distribution model is richly parameterized and various assessment tasks are used to estimate its parameters. These tasks include the revision of opinion in the light of hypothetical data, the assessment of credible intervals, and a task commonly performed in cue-weighting experiments. A new assessment task is also introduced. In addition, implementation of the method in an interactive computer program is described and the method is illustrated with a practical example.     

Clinical judgment in forensic neuropsychology: A comment on the risks of claiming more than can be delivered

There is a vast and growing literature in psychology demonstrating the general limits of human judgment and clinical inference. These findings clearly apply in the new specialty of clinical neuropsychology, and there is little empirical research to support the widespread belief that judgmental accuracy correlates substantially with experience, professional stature, or reputation as a neuropsychologist. However, the demand characteristics of expert testimony in the forensic arena may encourage individual neuropsychologists to state or intimate that they have unique or special expertise in understanding brain-behavior relationships, or in predicting outcomes following cerebral insult or injury. These claims will be increasingly difficult to substantiate as attorneys become more conversant with the literature on human judgment.