Shishkin Sergey L, Ganin Ilya P, Basyul Ivan A, Zhigalov Alexander Y, Kaplan Alexander Ya
Faculty of Biology, M. V. Lomonosov Moscow State University, 1/12, Leninskie Gory, Moscow, 119991, Russia.
J Integr Neurosci. 2009 Dec;8(4):471-85. doi: 10.1142/s0219635209002320.
One of the widely used paradigms for the brain-computer interface (BCI), the P300 BCI, was proposed by Farwell and Donchin as a variation of the classical visual oddball paradigm, known to elicit the P300 component of the brain event-related potentials (ERP). We show that this paradigm, unlike the standard oddball paradigm, elicit not only the P300 wave but also a strong posterior N1 wave. Moreover, we present evidence that the sensitivity of this ERP component to targets cannot be explained by the variations of the perceived stimuli energy. This evidence is based on comparing the ERP obtained for usual P300 BCI stimuli and for the "inverted" stimulation scheme with low stimulus related variations of light energy (gray letters on the light gray background, "highlighted" by very light darkening). Despite the dramatic difference between the stimuli in the standard and "inverted" schemes, no difference between N1 amplitudes were found, supporting the view that this component's sensitivity to targets cannot be based simply on "foveating" the target, but may be related to spatial attention mechanisms, which involvement is natural for the P300 BCI. Efforts to optimize the P300 BCI should address better use of both P300 and N1 waves.
脑机接口（BCI）中广泛使用的范式之一，即P300脑机接口，是由法韦尔和唐钦提出的，作为经典视觉Oddball范式的一种变体，该范式已知会引发大脑事件相关电位（ERP）的P300成分。我们表明，与标准Oddball范式不同，这种范式不仅会引发P300波，还会引发强烈的后部N1波。此外，我们提供的证据表明，这种ERP成分对目标的敏感性无法用感知到的刺激能量变化来解释。这一证据是基于比较常规P300脑机接口刺激和“反转”刺激方案所获得的ERP，后者具有与光能相关的低刺激变化（浅灰色背景上的灰色字母，通过非常轻微的变暗“突出显示”）。尽管标准方案和“反转”方案中的刺激存在巨大差异，但未发现N1振幅之间存在差异，这支持了这样一种观点，即该成分对目标的敏感性不能仅仅基于对目标的“注视”，而可能与空间注意机制有关，而空间注意机制的参与对P300脑机接口来说是很自然的。优化P300脑机接口的努力应更好地利用P300和N1波。
