中国科学院心理健康重点实验室知识库

摘要

背景：前瞻功能是指个体在头脑中提前模拟和体验未来事件的能力。个体通过想象和体验未来事件可能带来的愉悦或悲伤感受，从而做出趋近或回避的适应性行为。前瞻功能影响个体的情绪调节，决策，动机水平和目标导向行为。以往研究发现精神分裂症患者存在前瞻功能缺陷，然而目前尚未有研究探讨精神分裂症患者前瞻功能缺陷的神经机制。另一方面，虽然以往在健康人群中的研究发现工作记忆是前瞻功能的重要组成成分，但是目前尚不清楚工作记忆如何影响精神分裂症患者的前瞻能力。

方法：我们招募了37名精神分裂症患者和28名年龄、性别及受教育水平匹配的健康对照。所有被试完成了前瞻功能任务，字符数字广度测验和结构核磁共振成像扫描。研究采用基于体素的形态学分析（voxel-based morphometry，VBM）探讨两组被试的灰质体积，及其与前瞻功能和工作记忆的关系。

结果：与对照组相比，精神分裂症患者想象未来事件时细节量减少，清晰度下降。在患者组，工作记忆缺陷与细节量减少密切相关。VBM结果表明精神分裂症患者前额叶灰质体积的下降与细节量及清晰度的降低相关。此外，在患者组，右侧海马的灰质体积与细节量呈显著正相关。最后，中介效应分析发现，患者组右外侧前额叶的灰质体积在前瞻功能和工作记忆的关系中发挥了中介作用。

结论：精神分裂症患者的前瞻功能缺陷与前额叶及右侧海马灰质体积的下降相关。并且在精神分裂症患者中，右外侧前额叶的灰质体积可以中介工作记忆和前瞻功能的关系。

Background: Prospection refers to the ability to simulate and pre-experience future episodes in one’s mind. Through “preview” events and “pre-feel” the pleasures or pains, individuals could adjust their behaviour flexibly. Prospection is closely associated with emotion regulation, decision making, motivation and goal-directed behaviour. Although prospection impairments have been observed in patients with schizophrenia, little is known about the underlying neural mechanism of prospection in these patients. Although it is acknowledged that working memory is an important process underlying prospection in the healthy population, it is unclear for the involvement of working memory in prospection in patients with schizophrenia.

Methods: A prospection task and the Letter Number Span test were administered to 37 patients with schizophrenia and 28 healthy controls. All participants also underwent a structural MRI scan. Voxel-based morphometry (VBM) analysis was used to measure grey matter (GM) volume.

Results: Patients with schizophrenia generated less internal details and reported a lower level of vividness on the prospection task than the controls. Working memory impairments were correlated with decreased internal details in the schizophrenia group. GM reduction in the prefrontal cortex (PFC) was correlated with decreased internal details and vividness on the prospection task in schizophrenia patients. Moreover, GM volume of the right hippocampus was positively correlated with internal details in patients with schizophrenia. GM volume of the right lateral PFC was found to mediate the relationship between working memory and internal details in the schizophrenia group. However, no such significant findings were observed in healthy controls.

Conclusions: Prospection impairments were associated with GM reduction in the PFC and the right hippocampus in patients with schizophrenia. Furthermore, working memory could influence prospection through the right lateral PFC in this clinical group.