Woodruff P W, Wright I C, Bullmore E T, Brammer M, Howard R J, Williams S C, Shapleske J, Rossell S, David A S, McGuire P K, Murray R M
Department of Psychological Medicine, Institute of Psychiatry and King's College School of Medicine and Dentistry, London, United Kingdom.
Am J Psychiatry. 1997 Dec;154(12):1676-82. doi: 10.1176/ajp.154.12.1676.
The authors explored whether abnormal functional lateralization of temporal cortical language areas in schizophrenia was associated with a predisposition to auditory hallucinations and whether the auditory hallucinatory state would reduce the temporal cortical response to external speech.
Functional magnetic resonance imaging was used to measure the blood-oxygenation-level-dependent signal induced by auditory perception of speech in three groups of male subjects: eight schizophrenic patients with a history of auditory hallucinations (trait-positive), none of whom was currently hallucinating; seven schizophrenic patients without such a history (trait-negative); and eight healthy volunteers. Seven schizophrenic patients were also examined while they were actually experiencing severe auditory verbal hallucinations and again after their hallucinations had diminished.
Voxel-by-voxel comparison of the median power of subjects' responses to periodic external speech revealed that this measure was reduced in the left superior temporal gyrus but increased in the right middle temporal gyrus in the combined schizophrenic groups relative to the healthy comparison group. Comparison of the trait-positive and trait-negative patients revealed no clear difference in the power of temporal cortical activation. Comparison of patients when experiencing severe hallucinations and when hallucinations were mild revealed reduced responsivity of the temporal cortex, especially the right middle temporal gyrus, to external speech during the former state.
These results suggest that schizophrenia is associated with a reduced left and increased right temporal cortical response to auditory perception of speech, with little distinction between patients who differ in their vulnerability to hallucinations. The auditory hallucinatory state is associated with reduced activity in temporal cortical regions that overlap with those that normally process external speech, possibly because of competition for common neurophysiological resources.
作者探究了精神分裂症患者颞叶皮质语言区域的异常功能偏侧化是否与幻听易感性相关，以及幻听状态是否会降低颞叶皮质对外部言语的反应。
使用功能磁共振成像测量三组男性受试者在对言语进行听觉感知时诱发的血氧水平依赖信号：八名有幻听病史的精神分裂症患者（特质阳性），他们当时均未出现幻觉；七名无此病史的精神分裂症患者（特质阴性）；以及八名健康志愿者。对七名精神分裂症患者在实际经历严重的言语性幻听时以及幻觉减轻后再次进行检查。
对受试者对周期性外部言语反应的中位数功率进行逐体素比较，结果显示，与健康对照组相比，合并精神分裂症组的左侧颞上回该指标降低，而右侧颞中回升高。特质阳性和特质阴性患者在颞叶皮质激活功率方面无明显差异。对患者在经历严重幻觉时和幻觉轻微时的情况进行比较，结果显示在前一种状态下颞叶皮质，尤其是右侧颞中回，对外部言语的反应性降低。
这些结果表明，精神分裂症与颞叶皮质对言语听觉感知的左侧反应降低和右侧反应增加有关，对幻觉易感性不同的患者之间差异不大。幻听状态与颞叶皮质区域活动减少有关，这些区域与正常处理外部言语的区域重叠，可能是由于对共同神经生理资源的竞争。
