Silbersweig D A, Stern E, Frith C, Cahill C, Holmes A, Grootoonk S, Seaward J, McKenna P, Chua S E, Schnorr L
MRC Cyclotron Unit, Wellcome Department of Cognitive Neurology, Hammersmith Hospital, London, UK.
Nature. 1995 Nov 9;378(6553):176-9. doi: 10.1038/378176a0.
Hallucinations, perceptions in the absence of external stimuli, are prominent among the core symptoms of schizophrenia. The neural correlates of these brief, involuntary experiences are not well understood, and have not been imaged selectively. We have used new positron emission tomography (PET) methods to study the brain state associated with the occurrence of hallucinations in six schizophrenic patients. Here we present a group study of five patients with classic auditory verbal hallucinations despite medication, demonstrating activations in subcortical nuclei (thalamic, striatal), limbic structures (especially hippocampus), and paralimbic regions (parahippocampal and cingulate gyri, as well as orbitofrontal cortex). We also present a case study of a unique, drug-naive patient with visual as well as auditory verbal hallucinations, demonstrating activations in visual and auditory/linguistic association cortices as part of a distributed cortical-subcortical network. Activity in deep brain structures, identified with group analysis, may generate or modulate hallucinations, and the particular neocortical regions entrained in individual patients may affect their specific perceptual content. The interaction of these distributed neural systems provides a biological basis for the bizarre reports of schizophrenic patients.
幻觉，即在没有外部刺激时产生的感知，是精神分裂症核心症状中的突出表现。这些短暂的、不由自主的体验的神经关联尚未得到充分理解，也尚未进行过选择性成像研究。我们使用了新的正电子发射断层扫描（PET）方法来研究与六名精神分裂症患者幻觉发生相关的脑状态。在此，我们展示了一项对五名尽管接受了药物治疗仍患有典型听幻觉的患者的群体研究，结果显示皮层下核团（丘脑、纹状体）、边缘结构（尤其是海马体）以及边缘旁区域（海马旁回和扣带回，以及眶额皮质）出现激活。我们还展示了一个独特的、未服用过药物的患者的病例研究，该患者同时患有视幻觉和听幻觉，结果显示作为分布式皮层 - 皮层下网络一部分的视觉和听觉/语言联合皮层出现激活。通过群体分析确定的深部脑结构中的活动可能会产生或调节幻觉，而个体患者中参与的特定新皮层区域可能会影响他们特定的感知内容。这些分布式神经系统之间的相互作用为精神分裂症患者的奇异报告提供了生物学基础。
