Moritz Steffen, Woodward Todd S, Lambert Martin
Universitätsklinikum Hamburg-Eppendorf, Klinik für Psychiatrie und Psychotherapie, Germany.
Br J Clin Psychol. 2007 Jun;46(Pt 2):127-37. doi: 10.1348/014466506X129862.
A consistent body of studies suggests that schizophrenia patients are extremely hasty when making decisions, and generally opt for the strongest response alternative. This pattern of results is primarily based on studies conducted with the beads task, which requires participants to determine from which of two possible jars a series of beads has been drawn. We have recently proposed a liberal acceptance (LA) bias to account for decision-making biases in schizophrenia, which claims that under heightened ambiguity the jump to conclusions (JTC) bias is abolished in schizophrenia.
A total of 37 schizophrenia patients were compared with 37 healthy controls on different versions of the beads paradigm. For the first task, participants were required to rate the probability that a bead was being drawn from one of two jars, and had to evaluate after each bead whether the amount of presented information would justify a decision. The second task was a classical draws to decision experiment with two jars. The third task confronted participants with four possible jars. If JTC was ubiquitous in schizophrenia hasty convergence on one alternative would be predicted for all three tasks. In contrast, the LA account predicts an abolishment of the JTC effect in the final task.
Tasks 1 and 2 provide further evidence for the well-replicated JTC pattern in schizophrenia patients. In accordance with the LA hypothesis, no group differences were detected for task 3.
The present results confirm that JTC is not ubiquitous in schizophrenia: in line with the LA account a JTC bias in schizophrenia occurred under low but not high ambiguity. LA may partly explain the emergence of fixed, false beliefs.
一系列研究表明，精神分裂症患者在做决策时极其仓促，通常会选择最强烈的反应选项。这种结果模式主要基于使用珠子任务进行的研究，该任务要求参与者确定一系列珠子是从两个可能的罐子中的哪一个中抽取的。我们最近提出了一种宽松接受（LA）偏差来解释精神分裂症中的决策偏差，该偏差认为在高度模糊的情况下，精神分裂症患者的急于下结论（JTC）偏差会被消除。
在不同版本的珠子范式上，将37名精神分裂症患者与37名健康对照者进行比较。对于第一个任务，参与者需要对从两个罐子中的一个抽取珠子的概率进行评分，并且在每颗珠子之后必须评估所呈现的信息量是否足以做出决策。第二个任务是一个使用两个罐子的经典的抽取决策实验。第三个任务让参与者面对四个可能的罐子。如果JTC在精神分裂症中普遍存在，那么预计在所有三个任务中都会出现对一个选项的仓促趋同。相比之下，LA理论预测在最后一个任务中JTC效应会被消除。
任务1和任务2为精神分裂症患者中得到充分重复的JTC模式提供了进一步的证据。与LA假设一致，在任务3中未检测到组间差异。
目前的结果证实，JTC在精神分裂症中并非普遍存在：与LA理论一致，精神分裂症中的JTC偏差在低模糊度而非高模糊度情况下出现。LA可能部分解释了固定的错误信念的出现。
