Hirano Shogo, Hirano Yoji, Maekawa Toshihiko, Obayashi Choji, Oribe Naoya, Kuroki Toshihide, Kanba Shigenobu, Onitsuka Toshiaki
Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
J Neurosci. 2008 May 7;28(19):4897-903. doi: 10.1523/JNEUROSCI.5031-07.2008.
Schizophrenia impairs many cognitive functions, and abnormalities in language processing have been proposed as one of the bases for this disorder. Previously, it was reported that different magnetoencephalography (MEG) patterns of the evoked oscillatory activity (eOA) of 20-45 Hz to speech and nonspeech sounds were evidence of a fast mechanism for the representation and identification of speech sounds in humans. The current study tested the hypothesis that the schizophrenics would show abnormal neural oscillatory activity, as measured by eOA, to speech and nonspeech sounds. Twenty patients and 23 control subjects participated in this study. MEG responses to speech and nonspeech sounds were recorded and eOA power and phase locking at 20-45 Hz were analyzed. Patients showed significantly delayed peak latencies of the eOA power and phase locking to speech sounds in the left hemisphere and to nonspeech sounds in the right hemisphere. Patients also showed a significantly reduced eOA power to speech sounds in the left hemisphere in 0-50 ms and a significantly larger eOA power to speech sounds in the left hemisphere in 100-150 ms. In addition, the analyses of the lateralization index revealed the pattern of hemispheric lateralization to be the opposite in patients. These results indicated that patients showed different characteristics of eOA compared with normal controls, probably related to deficits in a fast mechanism for identifying speech sounds. Moreover, the present study suggests that schizophrenia might be characterized by an opposite pattern of hemispheric lateralization in auditory evoked oscillations.
精神分裂症会损害多种认知功能，语言处理异常被认为是这种疾病的基础之一。此前有报道称，20 - 45赫兹对语音和非语音声音的诱发振荡活动（eOA）的不同脑磁图（MEG）模式，是人类语音声音表征和识别快速机制的证据。当前研究检验了这样一个假设：精神分裂症患者对语音和非语音声音的神经振荡活动（通过eOA测量）会出现异常。20名患者和23名对照受试者参与了这项研究。记录了对语音和非语音声音的MEG反应，并分析了20 - 45赫兹时的eOA功率和锁相。患者在左半球对语音声音以及右半球对非语音声音的eOA功率和锁相的峰值潜伏期显著延迟。患者在0 - 50毫秒时左半球对语音声音的eOA功率也显著降低，而在100 - 150毫秒时左半球对语音声音的eOA功率显著增大。此外，对偏侧化指数的分析显示患者的半球偏侧化模式相反。这些结果表明，与正常对照组相比，患者表现出不同的eOA特征，这可能与语音声音识别快速机制的缺陷有关。此外，本研究表明精神分裂症可能以听觉诱发振荡中半球偏侧化的相反模式为特征。
