Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, USA.
Neuropsychologia. 2010 Oct;48(12):3563-72. doi: 10.1016/j.neuropsychologia.2010.08.005. Epub 2010 Aug 14.
The relationship between cognitive processing stages and event-related potential components has been extensively researched for single components, but even the simplest task comprises multiple electrophysiological and cognitive components. Here we examined the relationship between behavioral measures and several visual evoked potentials (VEPs) related to global motion onset during a visual motion discrimination task. In addition to reaction time and accuracy, the EZ diffusion model was used to characterize elements of the decision process. Results showed that latencies, but not amplitudes, from three VEP components reliably predicted about 40% of the variance in reaction times for motion discrimination. These included the latency from stimulus motion onset to N2 onset, the latency from N2 onset to N2 peak, and the latency from the N2 peak to the peak of a late positive potential. These latencies were also able to predict the rate of information accumulation during the decision process and the duration of non-decision processes, but not the observer's threshold (boundary) for making a response. This pattern of results is consistent with an interpretation of these three latencies as reflecting a non-specific visual perceptual process, a motion-specific process, and a decision process, respectively. The relationship between the earliest interval and drift rate estimated with the EZ model also supports the notion that early perceptual processing might be a constituent part of the decision process itself.
认知加工阶段与事件相关电位成分之间的关系已在单个成分方面得到广泛研究，但即使是最简单的任务也包含多个电生理和认知成分。在这里，我们研究了在视觉运动辨别任务中与整体运动起始相关的几种视觉诱发电位（VEPs）与行为测量之间的关系。除了反应时间和准确性外，EZ 扩散模型还用于描述决策过程的要素。结果表明，三个 VEP 成分的潜伏期而非振幅可靠地预测了运动辨别反应时间的约 40%的方差。这包括从刺激运动开始到 N2 开始的潜伏期、从 N2 开始到 N2 峰值的潜伏期以及从 N2 峰值到后期正电位峰值的潜伏期。这些潜伏期还能够预测决策过程中的信息积累速度和非决策过程的持续时间，但不能预测观察者做出反应的阈值（边界）。这种结果模式与将这三个潜伏期分别解释为反映非特定视觉感知过程、特定运动过程和决策过程的解释一致。EZ 模型估计的最早间隔和漂移率之间的关系也支持这样一种观点，即早期感知处理可能是决策过程本身的一个组成部分。
