Kaiser Stefan, Unger Joerg, Kiefer Markus, Markela Jaana, Mundt Christoph, Weisbrod Matthias
Department of Psychiatry, University of Heidelberg, Heidelberg, Germany.
Psychiatry Res. 2003 Apr 1;122(3):169-84. doi: 10.1016/s0925-4927(03)00004-0.
Growing evidence suggests an impairment of executive control functions in depression. The aim of this study was to investigate whether depressive patients show a specific impairment of executive control in a response inhibition task and to investigate its neurophysiological correlates using event-related potentials. We analyzed data from 16 patients with unipolar depression and 16 healthy controls using an auditory Go/Nogo task. High resolution event-related potentials (ERPs) were recorded. Depressive patients performed similar to controls in the Go task, but worse in the Nogo task, which required response inhibition. ERPs revealed the neurophysiological correlate of this deficit. Both groups showed the same voltage pattern in the Go task. However, in the Nogo task depressive patients showed a reduction of an early fronto-temporal positivity in the N2 time window, which was associated with response inhibition in healthy subjects. This effect could not be explained by increased task difficulty in the Nogo task. There was no difference between groups in later stages of processing as indexed by the P3 complex. Therefore, the findings suggest a specific deficit in response inhibition, which requires executive control. This deficit is thought to reflect dysfunctional activation of the network subserving executive control during an early stage of cortical processing.
越来越多的证据表明抑郁症患者存在执行控制功能受损的情况。本研究的目的是调查抑郁症患者在反应抑制任务中是否表现出特定的执行控制受损，并使用事件相关电位研究其神经生理学相关性。我们使用听觉Go/NoGo任务分析了16名单相抑郁症患者和16名健康对照者的数据。记录了高分辨率事件相关电位（ERP）。抑郁症患者在Go任务中的表现与对照组相似，但在需要反应抑制的NoGo任务中表现较差。ERP揭示了这种缺陷的神经生理学相关性。两组在Go任务中表现出相同的电压模式。然而，在NoGo任务中，抑郁症患者在N2时间窗口的早期额颞区正性波降低，而在健康受试者中该正性波与反应抑制相关。这种效应不能用NoGo任务中增加的任务难度来解释。以P3复合波为指标的后期加工阶段，两组之间没有差异。因此，研究结果表明在需要执行控制的反应抑制方面存在特定缺陷。这种缺陷被认为反映了在皮质加工早期阶段，执行控制网络的功能失调激活。
