Psychiatry Department, University Medical Center Utrecht & Rudolf Magnus Institute for Neuroscience, Utrecht, The Netherlands.
PLoS One. 2012;7(9):e43516. doi: 10.1371/journal.pone.0043516. Epub 2012 Sep 6.
Auditory verbal hallucinations (AVH) are not only among the most common but also one of the most distressing symptoms of schizophrenia. Despite elaborate research, the underlying brain mechanisms are as yet elusive. Functional MRI studies have associated the experience of AVH with activation of bilateral language-related areas, in particular the right inferior frontal gyrus (rIFG) and the left superior temporal gyrus (lSTG). While these findings helped to understand the neural underpinnings of hearing voices, they provide little information about possible brain mechanisms that predispose a person to experience AVH, i.e. the traits to hallucinate. In this study, we compared resting state connectivity between 49 psychotic patients with chronic AVH and 49 matched controls using the rIFG and the lSTG as seed regions, to identify functional brain systems underlying the predisposition to hallucinate. The right parahippocampal gyrus showed increased connectivity with the rIFG in patients as compared to controls. Reduced connectivity with the rIFG in patients was found for the right dorsolateral prefrontal cortex. Reduced connectivity with the lSTG in patients was identified in the left frontal operculum as well as the parietal opercular area. Connectivity between the lSTG and the left hippocampus was also reduced in patients and showed a negative correlation with the severity of hallucinations. Concluding, we found aberrant connectivity between the seed regions and medial temporal lobe structures which have a prominent role in memory retrieval. Moreover, we found decreased connectivity between language-related areas, indicating aberrant integration in this system potentially including corollary discharge mechanisms.
听觉言语幻觉 (AVH) 不仅是精神分裂症最常见的症状之一，也是最令人痛苦的症状之一。尽管进行了精心的研究，但潜在的大脑机制仍难以捉摸。功能磁共振成像研究将 AVH 的体验与双侧语言相关区域的激活联系起来，特别是右侧额下回 (rIFG) 和左侧颞上回 (lSTG)。虽然这些发现有助于理解听到声音的神经基础，但它们提供的关于可能使人容易产生 AVH 的大脑机制的信息很少，即产生幻觉的特征。在这项研究中，我们比较了 49 名患有慢性 AVH 的精神病患者和 49 名匹配对照者的静息状态连接，使用 rIFG 和 lSTG 作为种子区域，以确定产生幻觉的倾向的潜在功能大脑系统。与对照组相比，患者的右侧海马旁回与 rIFG 的连接增加。与 rIFG 的连接减少，在患者的右侧背外侧前额叶皮质中发现。患者的 lSTG 与左侧额下回以及顶叶回的连接减少。lSTG 和左侧海马之间的连接在患者中也减少，并与幻觉的严重程度呈负相关。总之，我们发现种子区域与内侧颞叶结构之间存在异常连接，内侧颞叶结构在记忆检索中起着重要作用。此外，我们发现语言相关区域之间的连接减少，表明该系统的整合异常，可能包括伴随放电机制。
