Abstract: The valence-arousal conflict theory assumed both valance and arousal would trigger approaching or withdrawing tendencies. And it predicted the evaluation process of emotional stimuli should be affected considering whether valence and arousal triggered conflicting or congruent motivational tendencies. However, most previous studies have only revealed the interaction between valence and arousal, instead of directly proving the interactive links between valence, arousal and motivational tendencies. To address this question, the present study investigated the effects of valence and arousal on approach/avoidance tendencies using two experiments. In experiment 1, participants (N=61) were asked to evaluate subjective approach vs. withdrawal tendencies toward emotional expressions from Chinese Facial Affective Picture System (CFAPS) that systematically varied in valence and arousal. The results of Experiment 1 showed that participants reported a stronger approach tendency towards mildly arousing expressions and positive expressions relative to highly arousing expressions and negative expressions. And participants reported the evaluated the strongest withdrawal tendency towards negative highly arousing emotional expressions. In experiment 2 (N=36), we manipulated motivational tendency cues by triggering an approaching or avoiding cue. Participants were instructed to judge the valence of emotional words from Affective Norms English Words (ANEW) after visual-spatial cues which seems either approaching or withdrawing from participants by recording event-related potentials (ERP) to investigate whether valence or valence and arousal interactively foster implicit approach and avoidance tendencies. The behavioral results of experiment 2 showed a three way interaction (valence, arousal, and approach-withdrawal tendency) was observed such that evaluation reaction time was shorter if participants responded to a negative high-arousal stimulus than for negative low-arousal emotional words after a withdrawing cue, or if they responded to a positive low-arousal stimulus than of positive-high arousal emotional words after an approaching cue. The ERP results of Experiment 2 demonstrated that the N2 amplitude of negative emotional words after an approaching cue is larger than that of positive emotional words after an approaching cue, and the LPC amplitude of low-aroused emotional words after a withdrawing cue is larger than that of low-aroused emotional words after an approaching cue. The P1 amplitude of emotional words after an approaching cue is larger than that of emotional words after a withdrawing cue. The N400 amplitudes of negative-high arousing emotional words are larger than those of negative-low arousing words. In line with the valence-arousal conflict theory, these finding conformed that the facilitation of approached tendency by positive emotional stimuli or low arousal emotional stimuli. We provide preliminary evidence that emotional stimuli elicit conflicting action tendencies that are reflected in increased reaction times and increased activation in brain regions relevant for conflict monitoring.

Key words: motivational tendencies, emotional valence-arousal conflict, Event-related potential (ERP), approaching, withdrawing

摘要： 本研究通过两个实验考察不同效价度和唤醒度的情绪刺激是否存在动机倾向上的分离模式。实验1要求被试对表情图片的动机倾向（趋近/回避）进行主观评分，发现被试对低唤醒表情或积极表情有更加趋近的倾向。实验2以运动的线索启动动机倾向（趋近/回避），完成情绪词效价判断任务，从内隐的角度考察情绪刺激是否存在动机倾向上的分离模式，结果发现，被试对动机倾向一致的情绪刺激的反应时更快。趋近的消极情绪词比趋近的积极情绪词的N2波幅更大，远离的低唤醒情绪词比趋近的低唤醒情绪词的LPC波幅更大。结果说明积极或者低唤醒的情绪刺激引发趋近倾向，而消极或高唤醒的情绪刺激引发回避倾向。

关键词: 动机倾向, 情绪效价-唤醒度冲突, 事件相关电位（ERP）, 趋近, 回避