应激心向对女性急性应激条件下工作记忆的影响

Mindset and the Effect of Acute Stress on Working Memory

为了探讨急性应激对工作记忆的影响,本研究引入应激心向的概念。实验1验证了社会性评价冷压测试的可靠性以及应激对工作记忆的影响,并探讨了急性应激条件下一般性应激心向与工作记忆的关系,结果发现,在急性应激条件下,女性的一般性应激心向不影响工作记忆的表现。实验2通过视频诱发被试的情境性应激心向,发现应激有利心向组比应激有害心向组在工作记忆任务中的表现更好,且应激心向得分与任务的准确率成正相关。研究表明女性在应激条件下的工作记忆表现会受具体应激心向的影响。

Everyone is familiar with acute stress. We experience it in varying forms and degrees every day. Acute stress in humans triggers the release of glueocorticoids （GCs） and influences performance in working memory （WM） tasks. This memory system relies on the prefrontal cortex （PFC）, where GC-binding receptors are present. It is well known that stressful experiences may affect WM, but the results concerning the influence of acute stress on WM are quite heterogeneous with no impairing or enhancing effects being reported. One factor which might mediate the effects of acute stress on WM is stress mindset. The main purpose of this research is to test the effect of stress mindset on WM under acute stress within female participants. Previous studies revealed that stress mindset is associated with moderate cortisol under stress, so we predicted that having a stress-enhancing mindset would contribute to better performance in working memory tasks under acute stress. In Study 1, we investigated the reliability of the Socially Evaluated Cold Pressor Test （SECPT） to elicit stress responses in samples of Chinese females and tested the relationship between general stress mindset and WM performance under acute stress. A total of 55 female university students were tested and were randomly assigned to a ＂stress＂ or ＂no stress＂ group. The participants completed several scales （SMM-G, PANAS and Stress VAS）, then performed the standardized SECPT protocol or they put their hand into lukewarm water respectively, during which several subjective measures （PANAS and Stress VAS） and objective measures （heart rate and skin conductance） were assessed. Then, participants performed an n-back task to measure WM performance after completing the SECPT. Results showed that female participants exhibited a significant increase in heart rate and skin conductance, and reported more negative emotion and stress following the SECPT. And general stress mindset was not significantly related to WM performance in reaction time and accuracy rate in both 1-back task and 3-back task. In study 2, we viewed mindset as a contextual factor, tested the effect of stress mindset in the specific context on WM performance under acute stress. A total of 58 female university students were recruited and were randomly assigned to a ＂stress-debilitating mindset＂ or ＂no stress-debilitating mindset＂ group. Firstly, the participants reported their stress level; then they watched two different video clips respectively to induce different mindsets. Thereafter, they performed the standardized the SECPT protocol, marked the Stress VAS, finished the SMM-S to measure their mindsets and finished n-back tasks including a 2-back and a 3-back task. Results showed that （1） The SMM was higher for those in the enhancing condition than those in the debilitating condition. （2） After the SECPT, participants reported higher stress level both in the enhancing condition and debilitating condition. （3） There was no significant difference in stress level between two groups after the SECPT. （4） Participants in the enhancing condition showed better WM performance under acute stress. In conclusion, the present study demonstrated that the SECPT is a protocol with good applicability in Chinese adult participants. Stress mindset indeed has an effect on WM performance under acute stress in female participants. This study provides support for the idea that the mindset may also matter in the domain of stress.