Ngan Elton T C, Vouloumanos Athena, Cairo Tara A, Laurens Kristin R, Bates Alan T, Anderson Cameron M, Werker Janet F, Liddle Peter F
Department of Psychiatry, University of British Columbia, Vancouver, Canada.
Neuroimage. 2003 Oct;20(2):889-97. doi: 10.1016/S1053-8119(03)00385-9.
Healthy subjects show increased activation in left temporal lobe regions in response to speech sounds compared to complex nonspeech sounds. Abnormal lateralization of speech-processing regions in the temporal lobes has been posited to be a cardinal feature of schizophrenia. Event-related fMRI was used to test the hypothesis that schizophrenic patients would show an abnormal pattern of hemispheric lateralization when detecting speech compared with complex nonspeech sounds in an auditory oddball target-detection task. We predicted that differential activation for speech in the vicinity of the superior temporal sulcus would be greater in schizophrenic patients than in healthy subjects in the right hemisphere, but less in patients than in healthy subjects in the left hemisphere. Fourteen patients with schizophrenia (selected from an outpatient population, 2 females, 12 males, mean age 35.1 years) and 29 healthy subjects (8 females, 21 males, mean age 29.3 years) were scanned while they performed an auditory oddball task in which the oddball stimuli were either speech sounds or complex nonspeech sounds. Compared to controls, individuals with schizophrenia showed greater differential activation between speech and nonspeech in right temporal cortex, left superior frontal cortex, and the left temporal-parietal junction. The magnitude of the difference in the left temporal parietal junction was significantly correlated with severity of disorganized thinking. This study supports the hypothesis that aberrant functional lateralization of speech processing is an underlying feature of schizophrenia and suggests the magnitude of the disturbance in speech-processing circuits may be associated with severity of disorganized thinking.
与复杂的非语音声音相比，健康受试者在听到语音声音时左颞叶区域的激活会增加。颞叶中语音处理区域的异常偏侧化被认为是精神分裂症的一个主要特征。事件相关功能磁共振成像被用于检验这样一个假设：在听觉奇偶数目标检测任务中，与复杂的非语音声音相比，精神分裂症患者在检测语音时会表现出异常的半球偏侧化模式。我们预测，在右半球，精神分裂症患者颞上沟附近语音的差异激活会比健康受试者更大，但在左半球，患者的差异激活会比健康受试者更小。14名精神分裂症患者（从门诊患者中选取，2名女性，12名男性，平均年龄35.1岁）和29名健康受试者（8名女性，21名男性，平均年龄29.3岁）在执行听觉奇偶数任务时接受扫描，其中奇偶数刺激要么是语音声音，要么是复杂的非语音声音。与对照组相比，精神分裂症患者在右颞叶皮质、左额上皮质和左颞顶交界处的语音和非语音之间表现出更大的差异激活。左颞顶交界处差异的大小与思维紊乱的严重程度显著相关。这项研究支持了这样的假设，即语音处理的异常功能偏侧化是精神分裂症的一个潜在特征，并表明语音处理回路中的干扰程度可能与思维紊乱的严重程度有关。
