Laboratory of Brain Imaging, Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093, Warsaw, Poland.
Department of Experimental Psychology, University of Oxford, Oxfordshire, United Kingdom.
Neuropsychologia. 2020 Oct;147:107564. doi: 10.1016/j.neuropsychologia.2020.107564. Epub 2020 Jul 21.
The P3 event-related potential has been known for over 50 years, but its function is still a matter of ongoing debate. Current theories interpret P3b either as a correlate of perceptual consciousness, or as reflecting cognitive processes, like working memory and executive functions. Unexpectedly, recent studies indicate that P3b might occur in response to unconsciously presented stimuli which, if further replicated, will be important for defining its functional role. Therefore, in the present study we investigated the P3b component in response to participants' own name - a stimulus which is subjectively extremely salient and known to evoke a robust P3b response. The self-name and control (other) names were presented supra- and subliminally (backward-masked), in a subjective rating task and in a forced-choice identification task. We found that a consciously perceived self-name evoked a P3b of larger amplitude than the other-name in both tasks, which confirms that the self-name was processed preferentially. When the self-name was presented subliminally it was associated with larger P3b amplitude than the other-name in the identification task, but not in the subjective rating task. This indicates that a salient stimulus can in principle modulate the P3b amplitude even when processed outside of awareness, but also that subliminal processing depends on the task-set and top-down factors. Taken as a whole, our results provide evidence against the interpretation of P3b as a correlate of consciousness (and more generally conflict with the Global Workspace Theory) and will allow a more precise description of the relation between P3b and cognitive processes.
P3 事件相关电位已经存在了 50 多年，但它的功能仍在争论之中。目前的理论将 P3b 解释为知觉意识的相关物，或者反映认知过程，如工作记忆和执行功能。出乎意料的是，最近的研究表明，P3b 可能是对无意识呈现的刺激的反应，如果进一步得到证实，这将对定义其功能作用非常重要。因此，在本研究中，我们调查了参与者自身姓名引起的 P3b 成分——这是一种主观上非常显著的刺激，已知会引起强烈的 P3b 反应。在主观评价任务和强制选择识别任务中，呈现了自身名和控制名（其他名）的顺行和逆行掩蔽刺激。我们发现，在两种任务中，有意识感知到的自身名引起的 P3b 幅度都大于其他名，这证实了自身名被优先处理。当自身名呈现为潜意识刺激时，它在识别任务中引起的 P3b 幅度大于其他名，但在主观评价任务中则不然。这表明，一个显著的刺激原则上可以调节 P3b 幅度，即使在无意识处理时也是如此，但潜意识处理也取决于任务设定和自上而下的因素。总的来说，我们的结果提供了反对将 P3b 解释为意识相关物的证据（更普遍地与全局工作空间理论相冲突），并将允许更精确地描述 P3b 与认知过程之间的关系。
