Knowledge Based Solution Strategies in Medical Reasoning

The techniques of propositionol analysis are used to examine the protocols of seven cardiologists in a task involving the diagnosis of a case of acute bacterial endocarditis and an explanation of its underlying pathophysiology. It is shown that the explanations of physicians making an accurate diagnosis can be accounted for in terms of a model consisting of pure forward reasoning through a network of causal rules, actuated by relevant propositions embedded in the stimulus text. These rules appear to derive from the physician's underlying knowledge base rather than any information in the text itself. In contrast, subjects with inacurate diagnoses tend to make use of a mixture of forward and backward reasoning, beginning with a high level hypothesis and proceeding in a top-down fashion to the propositions embedded in stimulus text, or to the generation of irrelevant rules.     

Age Differences on a Coincident Anticipation Task

Two experiments were performed as an initial attempt to explain age related limitations in response accuracy on a coincident anticipation task. Five- to 9-year-old boys and adult males participated in each experiment. They made horizontal arm movements in response to stimuli from a Bassin Anticipation Timer. The results of Experiment I confirmed the findings of previous studies, which showed that young children respond early to slow moving stimuli. They were most accurate at intermediate speeds; their responses deteriorated as speed was increased. Older children and adults were more accurate at slow to intermediate speeds; their performances also declined at fast stimulus velocities. Experiment II examined use of a stereotypic or default movement speed as an explanation for these results, particularly for young children. A most comfortable movement pace was determined for each subject and was used as a baseline speed for a subsequent timing task. Four other stimuli were selected in 0.8 mph increments from the baseline speed (two faster, two slower). In addition, selected trials for 6 subjects at each age were filmed at 32 fps. X-coordinates for these trials were obtained and smoothed at 5 Hz. Movement time data suggested that 5-year-olds used a preferred or stereotypic speed, since they were accurate only when responding to their baseline speed. Older subjects matched stimuli up to and including their baselines. Kinematic characteristics confirmed the general notion of preferred speed for 5-year-olds. These same measures demonstrated that older subjects were increasingly adaptable in their responses, despite a failure to respond more accurately. Consequently, the term “preferred speed” lacks generality as an explanatory concept. Age-related shifts in the ability to modify components of a response, like average movement velocity and number of corrections, were used to explain accuracy differences.     

Age difference on a coincident anticipation task: influence of stereotypic or "preferred" movement speed

Two experiments were performed as an initial attempt to explain age related limitations in response accuracy on a coincident anticipation task. Five- to 9-year-old boys and adult males participated in each experiment. They made horizontal arm movements in response to stimuli from a Bassin Anticipation Timer. The results of Experiment l confirmed the findings of previous studies, which showed that young children respond early to slow moving stimuli. They were most accurate at intermediate speeds; their responses deteriorated as speed was increased. older children and adults were more accurate at slow to intermediate speeds; their performances also declined at fast stimulus velocities. Experiment ll examined use of a stereotypic or default movement speed as an explanation for these results, particularly for young children. A most comfortable movement pace was determined for each subject and was used as a baseline speed for a subsequent timing task. Four other stimuli were selected in 0.8 mph increments from the baseline speed (two faster, two slower). In addition, selected trials for 6 subjects at each age were filmed at 32 fps. X-coordinates for these trials were obtained and smoothed at 5 Hz. Movement time data suggested that 5-year-olds used a preferred or stereotypic speed, since they were accurate only when responding to their baseline speed. older subjects matched stimuli up to and including their baselines. Kinematic characteristics confirmed the general notion of preferred speed for 5-year-olds. These same measures demonstrated that older subjects were increasingly adaptable in their responses, despite a failure to respond more accurately. Consequently, the term "preferred speed" lacks generality as an explanatory concept. Age-related shifts in the ability to modify components of a response, like average movement velocity and number of corrections, were used to explain accuracy differences.     

Examining Reasoning Skill Differences Between Expert and Novice Counselors

There is increasing interest in identifying the complex cognitive skills that constitute counseling expertise. Research from cognitive psychology suggests significant differences between experts and novices in their reasoning. This study examines the reasoning of expert and novice counselors engaged in a diagnostic task. Cases varied on “problem structure”—the extent to which problem-relevant information was clear and apparent. While an expertise by problem structure interaction was hypothesized, most of the differences were found across case type. Results suggest that the structure of the diagnostic problem may be an important variable affecting reasoning. The importance of problem structure for future research and training is discussed.     

Additivity pretraining and cue competition effects: developmental evidence for a reasoning-based account of causal learning

The effect of additivity pretraining on blocking has been taken as evidence for a reasoning account of human and animal causal learning. If inferential reasoning underpins this effect, then developmental differences in the magnitude of this effect in children would be expected. Experiment 1 examined cue competition effects in children's (4- to 5-year-olds and 6- to 7-year-olds) causal learning using a new paradigm analogous to the food allergy task used in studies of human adult causal learning. Blocking was stronger in the older than the younger children, and additivity pretraining only affected blocking in the older group. Unovershadowing was not affected by age or by pretraining. In experiment 2, levels of blocking were found to be correlated with the ability to answer questions that required children to reason about additivity. Our results support an inferential reasoning explanation of cue competition effects.     

Source credibility and syllogistic reasoning

Two experiments examined whether a source credibility effect would be observed for a syllogistic reasoning task. In the experiments, people were given two statements, presented as the results from a survey, followed by a conclusion that was supposedly made by one of two sources. In Experiment 1, one of the sources was described as honest and the other as dishonest, and in Experiment 2, one of the sources was described as an expert and the other as a non-expert. Because a pilot experiment showed that credibility can be overridden by people’s experience with a source, all conclusions in Experiments 1 and 2 were ones that were likely to be accepted (i.e., necessary and possible strong conclusions). Both experiments showed a clear source credibility effect, particularly for the invalid conclusions. These results, along with the belief bias effect and previous research with conditional reasoning, suggest that people can be influenced by extraneous context, such as the honesty or expertise of a source, in a syllogistic reasoning task.     

Weighting information from outside sources: a biased process

How do people utilize information from outside sources in their decisions? Participants observed a signal‐plus‐noise or noise‐alone event and then made a yes–no decision about whether a signal had occurred. Participants were provided with two information sources to aid decision making. Each source consisted of four components that provided estimates of signal likelihood. In Experiment 1, the two sources had equal overall accuracy but differed in the expertise and internal correlation of their components. A regression analysis indicated that participants overweighed the high‐expertise‐high‐correlation source. This bias occurred on trials when the aggregate opinions of the sources disagreed. In Experiment 2, both the overall accuracy of the source and its components were manipulated. Participants overweighed information from the higher accuracy source. These biases reflect people's sensitivity to across‐trial and within‐trial differences in the accuracy and internal consistency of information sources. Experiment 3 provided additional evidence supporting these conclusions. Copyright © 2004 John Wiley & Sons, Ltd.     

专家医生的知识结构及诊断推理方式

医学专长研究中“中间者效应”的发现,引发了研究者对专家医生知识结构的探讨。在“知识打包”的基础上,医生的临床知识以“疾病脚本”的方式组织起来。随着临床经验的增加,专家医生积累了丰富的疾病脚本。在临床诊断中,他们无需对病人所有的体征和症状进行仔细地和系统地分析,而是通过非分析性的推理方式——“模式识别”或“样例识别”便可自动激活与之匹配的疾病脚本,据此对病人做出迅速而准确的诊断。医学专长的本质就在于专家医生以“疾病脚本”的方式组织起来的知识结构。“适应性专长”代表了未来医学专长研究的新方向     

Domain Knowledge and Hindsight Bias among Poker Players

Hindsight bias occurs when individuals believe that events were more predictable after they have occurred than they actually were before they occurred. Although hindsight bias is a well‐studied phenomenon, few studies have examined the role of expertise in this bias. Two experiments investigated the relation between the magnitude of hindsight bias and self‐reported poker expertise (Experiment 1) and assessed poker knowledge (Experiment 2). In Experiment 1, self‐rated poker expertise was negatively correlated with hindsight bias. Experiment 2 employed memory and hypothetical hindsight conditions and found that poker knowledge was negatively correlated with hindsight bias in the memory condition, but unrelated to hindsight bias in the hypothetical condition. These results help elucidate the role of expertise in hindsight bias and provide additional support for the separate components view, which claims there are different forms of hindsight bias that are differentially affected by certain factors. Domain knowledge appears to be one of such factors. Copyright © 2013 John Wiley & Sons, Ltd.     

充分条件句语义关系知觉对条件推理的影响

作者通过实验考察了大学生被试对五种充分条件句语义关系知觉对其条件推理的影响。两个实验的结果表明,被试对条件句中前后件之间语义关系的知觉理解影响和调节其相应的条件推理的成绩。实验1新发现,被试对充分条件句后件对前件必要性的知觉理解存在难易差异,对许可句和定义句的后件必要性容易知觉,对偶然句、义务句和因果句的后件必要性难以知觉。实验2新发现,被试对充分条件句后件对前件必要性的知觉理解的难易差异导致被试在否定后件式推理成绩上的差异,对许可句和定义句的否定后件式推理成绩显著高于对偶然句、义务句和因果句的否定后件式推理成绩,对充分条件句否定后件式推理成绩随对后件必要性知觉增加而增加。     

The Curse of Expertise: When More Knowledge Leads to Miscalibrated Explanatory Insight

Does expertise within a domain of knowledge predict accurate self‐assessment of the ability to explain topics in that domain? We find that expertise increases confidence in the ability to explain a wide variety of phenomena. However, this confidence is unwarranted; after actually offering full explanations, people are surprised by the limitations in their understanding. For passive expertise (familiar topics), miscalibration is moderated by education; those with more education are accurate in their self‐assessments (Experiment 1). But when those with more education consider topics related to their area of concentrated study (college major), they also display an illusion of understanding (Experiment 2). This “curse of expertise” is explained by a failure to recognize the amount of detailed information that had been forgotten (Experiment 3). While expertise can sometimes lead to accurate self‐knowledge, it can also create illusions of competence.     

Dimensional interaction between color and pitch

In three experiments I investigated the nature of cross-modal dimensional interaction by testing speeded classification of the synesthetically corresponding dimensions of color (white-black) and pitch (high-low). Experiment 1 showed significant Garner interference when these dimensions were varied orthogonally--redundancy gain for positively correlated dimensions and redundancy loss for negatively correlated dimensions. Attributes from synesthetically congruent stimuli were classified faster than attributes from incongruent stimuli (a congruity effect). Experiment 2 tested a perceptual explanation of this interaction (i.e., that color and pitch are configural dimensions) by using Pomerantz's (1986) diagnostic (comparison of selective and divided attention performance). The configurality hypothesis received little support. Experiment 3 examined the effect of optional processes on color and pitch classification. The results suggest that partly strategic and partly mandatory components may constitute overall performance. Three alternative explanations of the color-pitch interaction--perceptual, semantic, and response based--are evaluated in the context of the present results.     

Does expertise and thinking mode matter for accuracy in judgments of job applicants’ cognitive ability?

The present research examined the role of thinking mode for accuracy in recruiters and laypeople’s judgments of applicants’ cognitive ability. In Study 1, students who relied on their intuition were somewhat less accurate. In Study 2, an experimental manipulation of thinking mode (intuitive vs analytical) revealed no apparent differences in accuracy. Moreover, there were no differences in accuracy or agreement between recruiters and laypeople. Examination of the use of specific resume content suggested that intuitive thinking corresponds to basing one’s judgments more on the way that applicants present themselves in their personal letter and less on diagnostic biographical information such as SAT scores. The findings point to the possibility that professional recruiters may not possess intuitive expertise in this context.     

Influence of familiar features on diagnosis: instantiated features in an applied setting

Medical diagnosis can be viewed as a categorization task. There are two mechanisms whereby humans make categorical judgments: "analytical reasoning," based on explicit consideration of features and "nonanalytical reasoning," an unconscious holistic process of matching against prior exemplars. However, there is evidence that prior experience can also operate at the level of individual "instantiated" features (Brooks & Hannah, 2006). The present studies examined instantiated features in medical diagnosis. Four "pseudopsychiatric" conditions, each described by four characteristic features, were taught to undergraduate psychology students. They practiced on additional cases, then were tested on new cases with features from two conditions. In Experiment 1, diagnoses associated with familiar features presented one or three times during practice were assigned a higher probability than those with novel features. Experiment 2 showed that the impact of feature frequency was dependent on its consistency with the case diagnosis. Experiment 3 showed that the effect of feature familiarity was not confined to cases with two equiprobable diagnoses. Experiment 4 showed that the effect remained after a 24 hour delay. These four studies demonstrated that features seen in practice have a greater influence on diagnosis than novel synonyms. In fact, seeing a feature once within the appropriate context (a patient case in which it is a member of the primary diagnosis) was sufficient to form a diagnostic association equivalent to instantiations seen four times in a different context. The results of these studies have implications for theories of categorization and for teaching clinical reasoning.     

Becoming a face expert

Expertise in recognizing facial identity, and, in particular, sensitivity to subtle differences in the spacing among facial features, improves into adolescence. To assess the influence of experience, we tested adults and 8-year-olds with faces differing only in the spacing of facial features. Stimuli were human adult, human 8-year-old, and monkey faces. We show that adults' expertise is shaped by experience: They were 9% more accurate in seeing differences in the spacing of features in upright human faces than in upright monkey faces. Eight-year-olds were 14% less accurate than adults for both human and monkey faces (Experiment 1), and their accuracy for human faces was not higher for children's faces than for adults' faces (Experiment 2). The results indicate that improvements in face recognition after age 8 are not related to experience with human faces and may be related to general improvements in memory or in perception (e.g., hyperacuity and spatial integration).     

Hypothetico-nomological aspects of medical diagnosis Part I: General structure of the diagnostic process and its hypothesis-directed stage

In medical diagnostic examination three main stages may be distinguished: (a) initial exploration, (b) hypothesis-directed investigation, and (c) final diagnosis making. The purpose of this work is to study some methodological problems concerning the second of the above stages of the diagnosis and to prepare a background for a mathematical model [30] of this process. In diagnostic problem solving, the reasoning proceeds along the main lines traced by some initial suggestions and passes through various intermediate elements which are connected with one another forming ramifying chains and nets of inferences and hypotheses. Such a complex mental construction is based on laws which form medical knowledge and reflect various regularities and relations, causal, structural, functional, and others. The main components of diagnostic reasoning may be divided into several classes according to their function and content: leading hypotheses, working hypotheses, main diagnostic hypotheses, statements accepted as certain, intermediary and reserve hypotheses, therapeutic suggestions of immediate consequence. In an example of diagnostic problem solving these types of propositions are defined and analysed. In diagnostic reasoning, as in every other process of rational problem solving, explanation of the observed symptoms and signs and testing of the explaining hypotheses play a predominant role. These procedures form successive, frequently numerous and diversified steps and stages of the reasoning, leading to the construction of a mental model of the patient's state. Some problems relative to the scheme of explanation, especially to that which is based on causal laws, are discussed.     

Relationships between self-determination theory and theory of planned behavior applied to physical activity and exercise behavior in chronic pain

This study examined the relationships between self-determination theory (SDT) and theory of planned behavior (TpB) applied to physical activity and exercise behavior (PA&E) in people with chronic pain. Two hundred and eleven adults with chronic musculoskeletal pain (28 males and 183 females, age range 18 to 82 years, mean age 43 years) were recruited from online support groups and clinic networks in the United States. Participants completed SDT measures relevant to PA&E on perceived autonomy support, autonomy, competence, and relatedness, as well as TpB measures relevant to PA&E on intention, attitudes, subjective norms, and perceived behavioral control. Correlational techniques and canonical correlation analysis were performed to examine the relationships and variance within and between theoretical dimensions. Overall, the SDT set accounted for 37% of the TpB variance and the TpB set accounted for 32% of the SDT set variance. The results indicate there are statistical similarities and differences between concepts in SDT and TpB models for PA&E. Using both empirical guidance and clinical expertise, researchers and practitioners should attempt to select and integrate non-redundant and complementary components from SDT, TpB, and other related health behavior theories.