社会与工程心理学研究室知识库

人们时刻处在生活和工作带来的挑战和应激（也称为压力）之下，应激对日常生活和心理健康的影响引起了广泛重视。应激与认知活动的关系非常复杂，众多针对不同认知任务和脑功能的研究结果表明，应激的影响既包括促进效应，也包括抑制效应。这种复杂性不仅由不同的应激源和应激强度造成，也与应激持续时间有关。大量研究关注特定应激源对认知和心理的影响，包括急性应激、慢性应激以及应激障碍，但是不同持续时间的应激如何影响认知和大脑的系统性研究仍然非常缺乏。同样重要的是，目前应激研究也有必要进一步拓展到更多的认知领域。视觉表象的生成和操作是人机交互中的重要认知活动，同时也是创造力的核心过程。人们也往往不得不在应激状态下解决问题或进行创造活动。另一方面，心理表象在许多应激相关心理疾病的发生发展中起到重要作用，在临床上也经常使用想象相关技术作为心理干预的手段。但极少研究探索应激与表象的关系。

本论文系统地考察基于不同持续时间的应激（即时的急性应激、反映当天应激水平的皮质醇觉醒反应以及慢性应激）与视觉表象之间的关系。采用表象形象度作为表象生成的指标，采用心理旋转任务的行为绩效和脑电作为表象操作的指标。 研究一采用特里尔社会应激测验诱发被试的急性心理应激反应， 研究 急性心理应激对心理旋转的影响。结果发现 与控制组相比 高应激组的 旋转相关负波(Rotate Related Negative RRN）波幅更小 ，而行为结果则没有差异。该结果表明高应激组的神经效能更高，表现为 利用较少的神经活动而达到了同样的旋转绩效。 研究二 关注当天皮质醇觉醒反应与同一天的两种视觉表象认知的关系。结果发现，皮质醇觉醒反应与视觉表象形象度有显著的正相关关系；但没有发现与心理旋转活动的行为绩效和神经活动的相关。这个结果提示我们，早晨醒来时的预期性应激水平越高，当天的视觉表象越形象。研究三关注慢性应激对表象生成和心理旋转的影响，慢性应激水平通过知觉压力量表进行测量，结果表明慢性应激与表象形象性没有显著的相关关系，但存在负相关 的趋势。而在心理旋转任务中，慢性应激水平越高， 0度的反应时越慢，该结果表明慢性应 激可能损害了心理旋转过程中的一般性认知加工过程。

以上结果显示了急性应激与慢性应激对视觉表象的不同影响，当前的和当天的急性应激往往促进了神经效能和表象；但慢性应激状态下，表象行为则受到了不利影响。本研究的结果再次论证了应激与认知活动之间复杂的关系，同时也对表象在人机交互领域的应用和临床诊治过程中表象的角色提供了理论启示。

People are under the challenge and stress induced by daily life and work at almost every moment. The impacts of stress on physical and mental health have attracted widespread attention. The relationship between stress and cognitive activities is complicated; studies forced on the effects of stress on different cognitive tasks and brain functions found that the effects of stress include both facilitation and inhibition. The complexity of the relationship between stress and cognition depends on not only the types and the intensity of stress but also the duration. Numerous studies focused on the influences of certain stressors that including acute stress, chronic stress, and long-time stress disorders on cognition and psychology. However, there still a lack of systematical research on how the stress of different duration influences cognition and brain. Furthermore, the research on the impacts of stress should consider involving more other cognitive activities, such as mental imagery. The generation and manipulation of visual imagery are essential for people in daily life, as well as the core process of creativity. And people also have to solve problems or create under pressure. But few studies focus on the relationship between stress and mental imagery. On the other hand, mental imagery plays a pivotal role in many stress disorders and clinicians can use imaging technology to treat such disorders. However, the cognitive and neural mechanism of the association between mental imagery and stress disorders remains unclear.

The present study measured responses of acute stress, the cortisol awakening response, and chronic stress, and used the vividness of visual imagery as the index of imagery generation, the behavioral and electrophysiological performance of mental rotation as the index of imagery manipulation, to investigated the relationship between time-dependent stress and visual mental imagery. Study One focused on the effect of acute psychological stress induced by Trier Social Stress Test on performances of mental rotation. The result showed a significant difference between the higher stress group and the control group. The amplitude of rotation related negative component (RRN) of the higher stress group was smaller than the control. However, no significant differences were found in behavioral results. The results suggested that participants with higher acute stress responses had higher neural efficiency to achieve the same level of behavioral performance as the control group. Study Tow focused on the relationship between cortisol awakening response and the same-day performances of mental imagery. Results showed a positive correlation between cortisol awakening and the vividness of visual imagery. No significant correlations were found between cortisol level and performances of mental rotation, including behavioral and electrophysiological. The result indicated that higher cortisol awakening response predicated a higher vividness of mental imagery on the same day. Study Three focused on the impacts of chronic stress on the vividness of mental imagery and the performances of mental rotation. Chronic stress was measured by the Perceived Stress Scale (PSS). Results showed that the correlation between the score of PSS and visual imagery vividness was not significant, but there was a negatively correlative tendency. That is to say, people with severer chronic stress tended to the poor performance of imagery generation. Results of the mental rotation task found a positive correlation between the score of PSS and the reaction time when participants responded to the letters that didn't rotate. It implied a deterioration in the general processing of the mental rotation task.

The results showed and the different effects between acute and chronic stress on visual imagery. In most case, acute stressors which happen in the current or in the same day enhance the behavioral performance and neural efficiency of mental imagery. However, chronic stress has negative effects on the same task. The findings demonstrate a complexly nonlinear relationship between stress and cognition, And the results also provide theoretical enlightenments for the application in human-computer interaction and the diagnosis of mental imagery in the clinic.