Department of Fundamental Neuroscience, Centre Médical Universitaire, University of Geneva, 1 Rue Michel Servet, CH-1211 Geneva, Switzerland. juliane.britz@unige.
Neuroimage. 2010 Feb 1;49(3):2774-82. doi: 10.1016/j.neuroimage.2009.10.033. Epub 2009 Oct 19.
Much of the variation in both neuronal and behavioral responses to stimuli can be explained by pre-stimulus fluctuations in brain activity. We hypothesized that also errors are the result of stochastic fluctuations in pre-stimulus activity and investigated the temporal dynamics of the scalp topography and their concomitant intracranial generators of stimulus- and response-locked high-density event-related potentials (ERPs) to errors and correct trials in a Stroop task. We found significant differences in ERP map topography and intracranial sources before the onset of the stimulus and after the initiation of the response but not as a function of stimulus-induced conflict. Before the stimulus, topographic differences were accompanied by differential activity in lateral frontal, parietal and temporal areas known to be involved in voluntary reorientation of attention and cognitive control. Differential post-response activity propagated both medially and laterally on a rostral-caudal axis of a network typically involved in performance monitoring. Analysis of the statistical properties of error occurrences revealed their stochasticity.
刺激引起的神经元和行为反应的大部分变异可以用刺激前脑活动的波动来解释。我们假设错误也是刺激前活动随机波动的结果，并研究了头皮地形图的时间动态及其伴随的颅内刺激和反应锁定高密度事件相关电位（ERPs）的发生器，以在 Stroop 任务中对错误和正确试验进行研究。我们发现，在刺激开始前和反应开始后，ERP 图地形和颅内源有显著差异，但不是作为刺激引起的冲突的函数。在刺激之前，地形差异伴随着已知参与自愿重新定向注意力和认知控制的外侧额、顶和颞区域的差异活动。反应后的差异活动沿一个通常涉及性能监测的网络的额-尾轴在中间和外侧传播。对错误发生的统计特性的分析表明它们具有随机性。
