School of Psychology, Bangor University, Bangor, Gwynedd, UK.
Psychol Med. 2013 Dec;43(12):2465-75. doi: 10.1017/S0033291712002760. Epub 2013 Jan 2.
Cognitive models have postulated that auditory hallucinations arise from the misattribution of internally generated cognitive events to external sources. Several experimental paradigms have been developed to assess this externalizing bias in clinical and non-clinical hallucination-prone samples, including source-monitoring, verbal self-monitoring and auditory signal detection tasks. This meta-analysis aims to synthesize the wealth of empirical findings from these experimental studies.
A database search was carried out for reports between January 1985 and March 2012. Additional studies were retrieved by contacting authors and screening references of eligible reports. Studies were considered eligible if they compared either (i) hallucinating and non-hallucinating patients with comparable diagnoses, or (ii) non-clinical hallucination-prone and non-prone participants using source-monitoring, verbal self-monitoring or signal detection tasks, or used correlational analyses to estimate comparable effects.
The analysis included 15 clinical (240 hallucinating patients and 249 non-hallucinating patients) and nine non-clinical studies (171 hallucination-prone and 177 non-prone participants; 57 participants in a correlation study). Moderate-to-large summary effects were observed in both the clinical and analogue samples. Robust and significant effects were observed in source-monitoring and signal detection studies, but not in self-monitoring studies, possibly due to the small numbers of eligible studies in this subgroup. The use of emotionally valenced stimuli led to effects of similar magnitude to the use of neutral stimuli.
The findings suggest that externalizing biases are important cognitive underpinnings of hallucinatory experiences. Clinical interventions targeting these biases should be explored as possible treatments for clients with distressing voices.
认知模型假设，听觉幻觉是由于将内部产生的认知事件错误归因于外部来源而产生的。已经开发了几种实验范式来评估临床和非临床易产生幻觉的样本中的这种外化偏差，包括来源监测、言语自我监测和听觉信号检测任务。本荟萃分析旨在综合这些实验研究的丰富实证发现。
对 1985 年 1 月至 2012 年 3 月期间的报告进行了数据库搜索。通过联系作者和筛选合格报告的参考文献，检索到其他研究。如果研究比较了（i）具有可比诊断的有幻觉和无幻觉患者，或（ii）使用来源监测、言语自我监测或信号检测任务的非临床易产生幻觉和不易产生幻觉的参与者，或使用相关分析来估计可比效应，则认为研究符合条件。
分析包括 15 项临床研究（240 名有幻觉的患者和 249 名无幻觉的患者）和 9 项非临床研究（171 名易产生幻觉的参与者和 177 名不易产生幻觉的参与者；57 名参与者进行了相关研究）。在临床和模拟样本中均观察到中等至较大的综合效应。在来源监测和信号检测研究中观察到稳健且显著的效应，但在自我监测研究中未观察到，这可能是由于该亚组中符合条件的研究数量较少。使用情感价值刺激会导致与使用中性刺激相似大小的效应。
这些发现表明，外化偏差是幻觉体验的重要认知基础。应该探索针对这些偏差的临床干预措施，作为治疗有困扰性声音的客户的可能方法。
