Abstract: Emotion plays a very important role in daily life of human beings. One of its most useful functions is to elicit full preparations for adaptive reactions. However, to develop effective behavioral strategies needs successful and effective encoding of emotional stimuli. There have been many researches on emotion processing about visual channel stimulus, such as facial expression, emotional pictures and so on. Researches on emotional speech processing are relatively few. In addition, whether processing of emotional prosody can be modulated by selective attention is still controversial. Therefore, this study aimed to explore the neural mechanism of emotional prosody processing and what roles can experimental task play on it. Two experiments were carried out using both event-related potentials (ERPs) and behavioral measures. In experiment 1, the task was emotion identification of the speech and in experiment 2, the task was gender identification of the speakers. Three kinds of emotional stimuli, ie., happy, neutral and anger prosody were used in both experiments, which were produced by two professional speakers, a male and a female news broadcaster. 23 college students and postgraduates participated in the first experiment, the other 25 participated in the second. Behavioral results showed that: Identification of emotional stimulus was faster than neutral stimulus in both experiments. And there was a negative bias of valence effect, reaction to anger stimuli was faster than to happy stimuli. ERP results showed that: (1) In 175-275ms, which is the time window of P2 component, emotional prosody processing can be modulated by experiment tasks. In the first experiment of emotion identification task, there was valence effect and negative bias, and anger emotion evokes more positive P2 component, but in the second experiment of gender identification task, no valence effect was found; (2) In the late stage of evaluation processing and response preparation, anger stimuli evoked more positive wave than neutral and happy emotion stimuli in both experiments, no significant difference was found between happy and neutral prosody, indicating that the negative stimuli had stronger stimulate correlation, thus get much more in-depth processing. These results suggested that, there were different cognitive mechanisms of emotional speech processing, compared with the neutral stimuli, emotional prosody can be processed more effectively. And to some extent, this process can be modulated by experimental tasks, especially in the second stage.

Key words: emotional prosody, valence, gender, event-related potential(ERP), P2

摘要： 采用ERP技术分别考察了情绪判断和性别判断任务下情绪韵律的加工进程。结果显示：在175-275ms时间段，情绪韵律的加工受实验任务的调节，情绪判断任务下存在效价主效应及负性偏向，愤怒比高兴和中性诱发了更正的P2成分，而性别判断任务则无效价效应。在后期评价加工及反应准备阶段（400-800ms），两种任务下，愤怒都比高兴和中性诱发了更正的晚成分。上述结果说明，不同情绪韵律的识别存在不同的认知机制，并在一定程度上会受加工任务的调节。

关键词: 情绪韵律,效价,性别,事件相关电位,P2