Brockhaus-Dumke Anke, Mueller Ralf, Faigle Ulrich, Klosterkoetter Joachim
Department of Psychiatry and Psychotherapy, University of Cologne, Kerpener Strasse 62, 50924 Cologne, Germany.
Schizophr Res. 2008 Feb;99(1-3):238-49. doi: 10.1016/j.schres.2007.10.034. Epub 2007 Dec 21.
Disturbances of auditory information processing have repeatedly been shown in schizophrenia. To contribute to a better understanding of the neurophysiological underpinnings of habituation in auditory processing and its disturbance in schizophrenia we used three different approaches to analyze auditory evoked responses, namely phase-locking (PL) analyses, single trial amplitudes, and averaged event-related potentials (P50 and N100). Given that brain oscillations reflect the neuronal correlates of information processing we hypothesized that PL and amplitudes reflect even more essential parts of auditory processing than the averaged ERP responses. In 32 schizophrenia patients and 32 matched controls EEG was continuously recorded using an auditory paired click paradigm. PL of the lower frequency bands (alpha and theta) was significantly reduced in patients whereas no significant differences were present in higher frequencies (gamma and beta). Alpha and theta PL and amplitudes showed a marked increase after the first click and to a minor degree after the second one. This habituation was more prominent in controls whereas in schizophrenia patients the response to both clicks differed only slightly. N100 suppression was significantly reduced in schizophrenia patients whereas no group differences were present with respect to the P50. This corresponded to the finding that gamma mostly contributed to the prediction of the P50 response and theta mostly to the N100 response. Our data showed that analyzing phase and amplitude in single trials provides more information on auditory information processing and reflects differences between schizophrenia patients and controls better than analyzing the averaged ERP responses.
精神分裂症患者反复出现听觉信息处理障碍。为了更好地理解听觉处理中习惯化的神经生理学基础及其在精神分裂症中的紊乱，我们采用了三种不同的方法来分析听觉诱发反应，即锁相（PL）分析、单次试验振幅和平均事件相关电位（P50和N100）。鉴于脑振荡反映了信息处理的神经元相关性，我们假设PL和振幅比平均ERP反应更能反映听觉处理的关键部分。在32例精神分裂症患者和32例匹配的对照组中，使用听觉配对点击范式连续记录脑电图。患者低频带（α和θ）的PL显著降低，而高频带（γ和β）无显著差异。α和θ的PL及振幅在第一次点击后显著增加，第二次点击后略有增加。这种习惯化在对照组中更为明显，而在精神分裂症患者中，对两次点击的反应仅有轻微差异。精神分裂症患者的N100抑制显著降低，而P50方面无组间差异。这与以下发现一致：γ主要影响P50反应的预测，θ主要影响N100反应。我们的数据表明，与分析平均ERP反应相比，分析单次试验的相位和振幅能提供更多关于听觉信息处理的信息，并且能更好地反映精神分裂症患者与对照组之间的差异。
