Lei Yi, Dou Haoran, Liu Qingming, Zhang Wenhai, Zhang Zhonglu, Li Hong
College of Psychology and Sociology, Shenzhen UniversityShenzhen, China.
Research Center for Brain and Cognitive Neuroscience, Liaoning Normal UniversityDalian, China.
Front Psychol. 2017 Apr 20;8:592. doi: 10.3389/fpsyg.2017.00592. eCollection 2017.
It has been long debated to what extent emotional words can be processed in the absence of awareness. Behavioral studies have shown that the meaning of emotional words can be accessed even without any awareness. However, functional magnetic resonance imaging studies have revealed that emotional words that are unconsciously presented do not activate the brain regions involved in semantic or emotional processing. To clarify this point, we used continuous flash suppression (CFS) and event-related potential (ERP) techniques to distinguish between semantic and emotional processing. In CFS, we successively flashed some Mondrian-style images into one participant's eye steadily, which suppressed the images projected to the other eye. Negative, neutral, and scrambled words were presented to 16 healthy participants for 500 ms. Whenever the participants saw the stimuli-in both visible and invisible conditions-they pressed specific keyboard buttons. Behavioral data revealed that there was no difference in reaction time to negative words and to neutral words in the invisible condition, although negative words were processed faster than neutral words in the visible condition. The ERP results showed that negative words elicited a larger P2 amplitude in the invisible condition than in the visible condition. The P2 component was enhanced for the neutral words compared with the scrambled words in the visible condition; however, the scrambled words elicited larger P2 amplitudes than the neutral words in the invisible condition. These results suggest that the emotional processing of words is more sensitive than semantic processing in the conscious condition. Semantic processing was found to be attenuated in the absence of awareness. Our findings indicate that P2 plays an important role in the unconscious processing of emotional words, which highlights the fact that emotional processing may be automatic and prioritized compared with semantic processing in the absence of awareness.
情绪词汇在无意识状态下能够被加工的程度一直以来都备受争议。行为学研究表明，即便没有任何意识，情绪词汇的含义也能够被理解。然而，功能磁共振成像研究显示，无意识呈现的情绪词汇并不会激活参与语义或情绪加工的脑区。为了阐明这一点，我们运用连续闪烁抑制（CFS）和事件相关电位（ERP）技术来区分语义加工和情绪加工。在连续闪烁抑制实验中，我们持续且稳定地向一名参与者的一只眼睛快速闪现一些蒙德里安风格的图像，从而抑制投射到另一只眼睛的图像。向16名健康参与者呈现消极、中性和打乱顺序的词汇，持续500毫秒。无论参与者是在可见还是不可见条件下看到刺激物，他们都要按下特定的键盘按钮。行为学数据显示，在不可见条件下，对消极词汇和中性词汇的反应时间没有差异，尽管在可见条件下消极词汇的加工速度比中性词汇快。ERP结果表明，消极词汇在不可见条件下引发的P2波幅比在可见条件下更大。在可见条件下，与打乱顺序的词汇相比，中性词汇的P2成分增强；然而，在不可见条件下，打乱顺序的词汇引发的P2波幅比中性词汇更大。这些结果表明，在有意识状态下，词汇的情绪加工比语义加工更敏感。发现在无意识状态下语义加工会减弱。我们的研究结果表明，P2在情绪词汇的无意识加工中发挥着重要作用，这凸显了一个事实，即在无意识状态下，与语义加工相比，情绪加工可能是自动且具有优先性的。
