Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Schizophr Res. 2020 Aug;222:202-208. doi: 10.1016/j.schres.2020.05.056. Epub 2020 Jun 5.
Jumping to conclusions (JTC) is the best established cognitive bias in schizophrenia and is increasingly targeted in interventions aimed to improve positive symptoms. To address shortcomings of the standard measure to capture JTC, the beads task, we developed a new variant-the box task-which was subsequently validated in people with elevated psychotic-like experiences. For the first time, the box task was administered in a sample of individuals with manifest schizophrenia. We hypothesized that patients with schizophrenia would display an elevated JTC bias relative to controls.
We recruited a large sample of 101 patients with schizophrenia and matched them to an online sample recruited from the general population. In the box task, participants must decide which of two kinds of colored balls are presented more often. Participants are told that the task may end prematurely, and that task performance will be counted as an error if no decision had been made before that point. The primary measure was the number of draws to decision (DTD), where fewer DTD corresponds to greater JTC.
In contrast to expectations, participants with schizophrenia showed significantly higher DTD (i.e., reduced JTC). Consistent with our previous findings, patients also displayed a lowered decision threshold compared to controls. Response confidence for the final decision was lower in patients and correlated with self-esteem and positive symptoms. While there was evidence that previous knowledge of the box task lowered DTD, exclusion of participants with experience on the box task did not substantially change results.
The study fits a growing body of experiments casting doubt on the generalizability of the JTC effect in schizophrenia across different tasks. While the study tentatively supports a liberal acceptance account of psychosis, caution is warranted and we recommend that research should explore and control for potentially important mediators (e.g., task difficulty, stress, test-taking attitudes).
跳跃结论（JTC）是精神分裂症中最成熟的认知偏差，并且越来越多地成为旨在改善阳性症状的干预措施的目标。为了解决标准测量方法（珠子任务）捕捉 JTC 的缺陷，我们开发了一种新的变体 - 盒子任务 - 该任务随后在具有升高的类精神病体验的人群中进行了验证。盒子任务首次在表现出精神分裂症的个体样本中进行了管理。我们假设精神分裂症患者相对于对照组会表现出更高的 JTC 偏差。
我们招募了 101 名精神分裂症患者的大样本，并将他们与从一般人群中招募的在线样本相匹配。在盒子任务中，参与者必须决定两种颜色的球哪种出现的频率更高。参与者被告知任务可能会提前结束，如果在此之前没有做出决定，则将任务表现算作错误。主要措施是做出决定的 Draws to Decision（DTD）数量，其中 DTD 越少表示 JTC 越高。
与预期相反，精神分裂症患者的 DTD 明显更高（即 JTC 降低）。与我们之前的发现一致，与对照组相比，患者的决策阈值也降低了。最终决策的反应置信度较低，与自尊和阳性症状相关。虽然有证据表明先前对盒子任务的了解降低了 DTD，但排除具有盒子任务经验的参与者并没有实质性地改变结果。
该研究支持了越来越多的实验结果，这些结果对不同任务中精神分裂症中 JTC 效应的普遍性提出了质疑。虽然该研究暂时支持精神病的自由接受理论，但需要谨慎，并建议研究应探索和控制潜在的重要中介因素（例如，任务难度，压力，应试态度）。
