Moritz Steffen, Woodward Todd S, Hausmann Daniel
Klinik für Psychiatrie und Psychotherapie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.
Schizophr Bull. 2006 Apr;32(2):327-31. doi: 10.1093/schbul/sbj034. Epub 2005 Dec 9.
Previous studies indicate that schizophrenia patients draw decisions more hastily than controls. The aim of the present study was to obtain convergent evidence with a new paradigm, designed after the Who Wants to Be a Millionaire television game show. Thirty-two schizophrenia patients and 38 healthy subjects were administered 20 knowledge questions, along with 4 response alternatives. Participants were required to provide probability estimates for each alternative. Whenever a subject was confident that one of the alternatives was correct or was wrong, the subject was asked to indicate this via a decision or rejection rating. Thus, probability estimates and decisions were independently assessed, allowing determination of the point at which probability estimates translate into decisions. Patients and controls gave comparable probability estimates for all alternatives. However, patients committed more erroneous responses, owing to their making decisions in the face of low subjective probability ratings and rejecting alternatives despite rather high probability ratings. The results provide further evidence for the claim that schizophrenia patients make strong judgments based on little information. We propose that a lowered threshold for accepting alternatives provides a parsimonious explanation for the data-gathering bias reported in the literature.
先前的研究表明，精神分裂症患者做出决策比对照组更加仓促。本研究的目的是采用一种新范式来获得趋同证据，该范式是参照电视游戏节目《谁想成为百万富翁》设计的。32名精神分裂症患者和38名健康受试者接受了20道知识问题测试，每个问题有4个备选答案。要求参与者对每个备选答案给出概率估计。每当受试者确信其中一个备选答案正确或错误时，就要求他们通过决策或拒绝评分来表明这一点。因此，概率估计和决策是独立评估的，从而能够确定概率估计转化为决策的临界点。患者和对照组对所有备选答案给出的概率估计相当。然而，患者做出的错误反应更多，因为他们在主观概率评分较低时就做出决策，并且在概率评分相当高时仍拒绝备选答案。这些结果为精神分裂症患者基于极少信息做出强烈判断这一说法提供了进一步证据。我们认为，接受备选答案的阈值降低为文献中报道的数据收集偏差提供了一个简洁的解释。
