Neuroscience Division, Department of Psychiatry, University Medical Centre Utrecht and Rudolf Magnus Institute for Neuroscience, Heidelberglaan, The Netherlands.
Brain. 2010 Dec;133(Pt 12):3734-44. doi: 10.1093/brain/awq313. Epub 2010 Nov 19.
Decreased language lateralization is a well-replicated finding in psychotic patients. It is currently unclear, however, whether this abnormality is related to a particular symptom of psychosis or to psychosis in general. It has been argued that decreased language lateralization may be related to auditory verbal hallucinations. To elucidate this, these hallucinations should be studied in isolation. Thirty-five patients with a psychotic disorder, 35 non-psychotic subjects with relatively isolated auditory verbal hallucinations and 35 healthy control subjects participated in this study. All subjects were scanned on a 3T magnetic resonance imaging scanner, while covertly performing a paced verbal fluency task. In order to measure performance on the task, one additional task block was presented during which subjects had to generate words overtly. In addition to calculating language lateralization indices, group-wise brain activation during verbal fluency was compared between the three groups. Task performance was nearly maximal for all groups and did not differ significantly between the groups. Compared with the healthy control subjects and non-psychotic subjects with auditory verbal hallucinations, language lateralization was significantly reduced for the patient group. In addition, the patients displayed significantly greater activity in the right precentral gyrus and left insula when compared with the healthy control subjects and the non-psychotic subjects with auditory verbal hallucinations. Furthermore, the patients showed greater activity in the right superior parietal lobule when compared with the healthy control subjects. Lateralization indices did not differ significantly between the non-psychotic subjects with auditory verbal hallucinations and the healthy control subjects. Moreover, there were no significant differences in brain activation during verbal fluency between the two non-psychotic groups. As language lateralization was not significantly reduced in the non-psychotic individuals with auditory verbal hallucinations, a direct relationship between auditory verbal hallucinations and decreased language lateralization can not be established at present.
语言侧化程度降低是精神分裂症患者中一个得到充分验证的发现。然而，目前尚不清楚这种异常是与精神分裂症的特定症状有关，还是与精神分裂症本身有关。有人认为，语言侧化程度降低可能与听觉言语幻觉有关。为了阐明这一点，应该孤立地研究这些幻觉。本研究纳入 35 例精神分裂症患者、35 例有相对孤立的听觉言语幻觉但无精神病的受试者和 35 名健康对照者。所有受试者均在 3T 磁共振成像扫描仪上进行扫描，同时进行隐蔽的言语流畅性任务。为了测量任务表现，在额外的一个任务块中，要求受试者进行言语生成。除了计算语言侧化指数外，还比较了三组在言语流畅性任务中的脑激活情况。所有组的任务表现几乎都达到了最大值，且组间差异无统计学意义。与健康对照组和有听觉言语幻觉但无精神病的受试者相比，患者组的语言侧化程度显著降低。此外，与健康对照组和有听觉言语幻觉但无精神病的受试者相比，患者的右中央前回和左脑岛显示出更大的活动。此外，与健康对照组相比，患者的右顶叶上回显示出更大的活动。有听觉言语幻觉但无精神病的受试者与健康对照组的侧化指数差异无统计学意义。此外，两个无精神病组在言语流畅性期间的脑激活也没有显著差异。由于有听觉言语幻觉但无精神病的个体的语言侧化程度没有显著降低，因此目前不能确定听觉言语幻觉与语言侧化程度降低之间存在直接关系。
