Brébion G, Smith M J, Amador X, Malaspina D, Gorman J M
Institute of Psychiatry, Department of Psychological Medicine, London, England.
J Nerv Ment Dis. 1998 Oct;186(10):604-9. doi: 10.1097/00005053-199810000-00003.
The purpose of this experiment was to replicate and extend to a memory task Bentall and Slade's (1985) finding that hallucinations in schizophrenic patients were linked to a liberal decision bias. A word recognition task was administered to 40 schizophrenic patients and 40 normal controls that yielded two indices of performance: an index of discrimination accuracy (Pr) and one of decision bias (Br). Patients obtained a lower Pr than controls, whereas Br was similar in both groups. In patients, Br was selectively correlated with positive symptomatology: the more the positive symptoms, the more liberal the bias. In particular, there was a specific correlation between decision bias and hallucinations. Conversely, Pr was inversely correlated with severity of depression, but not with either positive or negative symptoms. Thus, positive symptomatology may be linked more to difficulties in distinguishing between representations of internal versus external events than to deficits in encoding external events.
本实验的目的是重复并将本塔尔和斯莱德（1985年）的研究结果扩展到一项记忆任务中，该研究发现精神分裂症患者的幻觉与宽松的决策偏差有关。对40名精神分裂症患者和40名正常对照者进行了一项单词识别任务，该任务产生了两个表现指标：辨别准确率指标（Pr）和决策偏差指标（Br）。患者的Pr低于对照组，而两组的Br相似。在患者中，Br与阳性症状选择性相关：阳性症状越多，偏差越宽松。特别是，决策偏差与幻觉之间存在特定的相关性。相反，Pr与抑郁严重程度呈负相关，但与阳性或阴性症状均无相关性。因此，阳性症状可能更多地与区分内部与外部事件表征的困难有关，而不是与编码外部事件的缺陷有关。
