关键词: 心理应激, 应激反应程度, 心理韧性, 记忆

Abstract: Stress has become an omnipresent aspect of modern life. Nowadays, young adults are vulnerable to acute psychological stress in modern competitive society since it poses serious threat to memory performance in daily working and learning. Psychological stress has traditionally been defined either as a stimulus (often referred to as a stressor) to the person with laboratory shock or loss of job, or as a response characterized by physiological arousal and negative affect, such as anxiety. It is well established that acute psychological stress has an immense impact on cognition among healthy populations. However, previous research exploring the interaction between the level of acute psychological stress and cognition has not received enough attention. Furthermore, the role of resilience between acute psychological stress and memory among healthy adults has also long been ignored in previous research. Resilience, as a crucial facet of mental health, plays an essential role in acute psychology and subsequent cognitive processing. In addition, resilience, as a positive mental characteristics, is beneficial to people in adversity. However, little is known about how acute psychological stress interacts with memory among the population of healthy young adults, especially how acute psychological stress and memory are modulated by resilience. The present study aims to investigate the effect of acute psychological stress on memory and the moderating effect of resilience on psychological stress and memory. Fifty-six healthy volunteers were randomly assigned to two groups, with 36 participants (28 females, 8 males) in the stress group and 20 participants (18 females, 2 males) in the control group. The control group directly entered into a 15-minute memory test after a 5-minute rest. The stress group began with a 5-minute rest and then made a self-report of their subjective stress levels, the time point of which was termed as A1. The stress group immediately incorporated the questionnaire Connor Davidson Resilience Scale (CD-RISC) and Beck Depression Inventory (BDI), and subsequently were exposed to TTST for an addition 11-minute. Participants of the stress group then self-reported their current subjective stress levels again, the time point of which was termed as A2. Finally they entered into the memory test of 15-minute and then made self-report subjective stress level, the time point of which was termed as A3. According to score in TSST, the stress group was subsequently divided into the high-stress group and low-stress group according to their subjective report of stress level. One-way ANOVA of memory indicated that the main effect of psychosocial stress was significant (F(1, 55) =18.23, p < .01, η2= .25), and the memory in the stress group of acute psychological stress was poorer than that of the control group. We then carried out repeated measures ANOVA of subjective stress level, comprising the within-subjects factor Measurement Time Point (3：A1, A2, A3) and the between-subjects factor Stress (high stress group vs. low stress group). Results showed that the main effect of time was significant (F (2, 68) = 41.33, p < .01, η2 = .55) and both A1 and A3 were significantly lower than A2 in the level of psychological stress (p < .01). Secondly, the main effect of group was also significant (F (1, 34) = 61.44, p < .01, η2 = .64), the higher stress group had a significant higher subjective level of psychological stress than that of low stress group. Additionally, one way ANOVA of memory in the stress group revealed that there was significant main effect on memory (F (1, 35) = 31.22, p < .01, η2= .48 ). The higher stress indicated poorer memory performance than that of low stress. Finally, a hierarchical regression analysis was adopted to investigate the moderating of resilience in relationship between psychological stress and memory performance. Results revealed that higher psychological stress predicted a significantly worse memory performance (β=-4.585, p <.001), while higher resilience predicted significant better memory performance(β=.152, p <. 001). The interaction between psychological stress and resilience revealed a significant positive effect in memory performance (β=.307, p<.01). To our knowledge, the present study firstly attempted to explore how resilience moderates the relationship between acute psychological stress and memory performance. Our findings corroborated well with theory of cognitive resource distribution and reallocation. Resilience is believed to be involved in the coordination process of cognitive resource reallocation. It is therefore indicated that resilience can be a potential factor to improve people with higher acute psychological stress in our daily life. Hopefully, our findings in the current research could provide a comprehensive understanding of the mechanism underlying the interaction of memory performance and psychological stress.

Key words: Acute Psychological Stress, Stress Response, Resilience, Memory