Lencer Rebekka, Nagel Matthias, Sprenger Andreas, Heide Wolfgang, Binkofski Ferdinand
Department of Psychiatry and Psychotherapy, University of Luebeck, Ratzeburger Allee 160, 23538 Luebeck, Germany.
Neuroimage. 2005 Feb 15;24(4):1256-9. doi: 10.1016/j.neuroimage.2004.11.013. Epub 2004 Dec 30.
Smooth-pursuit eye movements are the essential tool for a clear and stable visual perception of our environment by matching eye velocity to the velocity of moving objects. However, in about 50% of schizophrenic patients, this ability is disturbed. To reveal the cortical mechanisms that underlie this deficit, eye velocity-related neuronal activity was analyzed by functional magnetic resonance imaging (fMRI). Blocks of constant velocity ramps (10 degrees/s) were presented to 17 patients with schizophrenia and 16 matched controls while assessing smooth-pursuit velocity (SPV) during scanning sessions. Using random-effects analysis, the parametric modulation of brain hemodynamic responses related to SPV was compared between both groups. In schizophrenic patients, reduced SPV was significantly correlated with a focal decrease of the hemodynamic response in the V5 complex (t = 4.21, P(FWE-corrected) = 0.005). Our results provide direct evidence for reduced neuronal activity in V5 as one major factor underlying abnormal SPV in schizophrenia and suggest impaired motion perception. They confirm hypotheses about a V5 deficit derived from psychophysiological studies with schizophrenic patients in which deficient motion perception (especially velocity discrimination) was associated with impaired smooth-pursuit performance.
平稳跟踪眼球运动是通过使眼球速度与移动物体速度相匹配来对我们的环境进行清晰稳定视觉感知的重要工具。然而，约50%的精神分裂症患者存在这种能力障碍。为了揭示这种缺陷背后的皮层机制，通过功能磁共振成像（fMRI）分析了与眼球速度相关的神经元活动。在扫描过程中评估平稳跟踪速度（SPV）时，向17名精神分裂症患者和16名匹配的对照组呈现恒定速度斜坡（10度/秒）的组块。使用随机效应分析，比较了两组之间与SPV相关的脑血流动力学反应的参数调制。在精神分裂症患者中，SPV降低与V5复合体中血流动力学反应的局部降低显著相关（t = 4.21，P（FWE校正）= 0.005）。我们的结果为V5中神经元活动减少作为精神分裂症中异常SPV的一个主要因素提供了直接证据，并提示运动感知受损。它们证实了来自对精神分裂症患者进行的心理生理学研究得出的关于V5缺陷的假设，其中运动感知缺陷（尤其是速度辨别）与平稳跟踪性能受损有关。
