中文摘要：

时间是认识和定义自我的框架之一。本研究采用两个实验，探讨心理时间旅行对任务自信的影响。实验1采用自由回忆或想象过去、未来事件的操纵，结果发现事件情绪效价影响任务自信，时间方向以事件情绪效价为中介间接影响任务自信，想象的未来事件比回忆的过去事件更积极，进而引发更高任务自信。实验2采用平衡回忆或想象事件的情绪效价的操纵，使效价与时间方向的作用相分离，结果发现：时间方向不影响任务自信，想象事件的情绪效价对任务自信的作用受到时间方向的调节。回忆过去事件时，效价不影响任务自信；而想象未来事件时，事件效价越积极，任务自信越高。对于时间旅行中的积极事件，时间旅行的方向不影响任务自信；而对于消极事件，想象未来所引发的任务自信低于回忆过去。结论：时间旅行的方向与想象事件的情绪效价共同作用于任务自信。

英文摘要：

Time is a framework of understanding and defining self. Individuals could mentally travel back to the past and forward to the future.Research has demonstrated that the self drives mental time travel, showing self-descriptions predict the valence and personal focus of future events,and self-concept （e.g. core self-evaluations, self-construal, self-efficacy） can drive the construction of past and future events. However, the cognitivemechanism of the effect of mental time travel on the self has not been explored yet. The task self-confidence in the present study means the extent ofindividuals＇ sureness about their performance in a task, and it is a part of the foundation of the cognitive construction of self-confidence. The currentstudy examined the effect of time direction and events＇ emotional valence on task self-confidence. This study included two experiments. In Experiment 1, forty undergraduates were randomly assigned to two groups （past and future）. First,they should recall or imagine self-related events freely in eight time periods respectively （e.g. the eight time periods of the past group were last year,the year before last year, 3 years ago, 4 years ago, 5 years ago, period of middle school, period of primary school, pre-school period）, and describedthem in the blanks below each time period. Afterwards, participants predicted their performance in the upcoming graphic reasoning test by ratingseven items. The average score of all seven items represented the task self-confidence. The procedure of Experiment 2 was similar to Experiment 1.Eighty undergraduates were randomly assigned to four groups （i.e. past-positive, past-negative, future-positive, future-negative）. According to whatwas required of each group, participants should recall or imagine self-related positive or negative events freely in four time periods respectively （e.g.the four time periods of the two past groups were last year, 3 years ago, 5 years ago, period of primary school）, and described them in the blanks. Afterde