轻度认知障碍和早期阿尔茨海默病患者情绪识别能力改变及其调节机制研究

Emotion recognition may be an important predictor of impairment in social functioning of patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD), and may also be the new target for early intervention. Previous researches have revealed the basic forms of the emotion recognition impairment in the patients. Further study should be focused on clarifying why emotion recognition impairment in positive emotion and negative emotion is inconsistent with each other? If there is specific cognitive processing mechanism during emotion recognition of the patients? Is there any cognitive factor modulating the processing? Based on previous studies, we formulated a hypothesis that impairments of spatial working memory and selective attention in MCI and AD patients may facilitate emotion recognition impairment of the patients by modulating perceptual load and attention window. Meanwhile, emotion valence itself may also contribute to the inconsistent emotion recognition by inducing attention bias. The present study would like to test the hypothesis using revised emotional neuropsychological experimental paradigms combined with event-related potential (ERP) technique which may provide a continuous measure of processing between a stimulus and a response. The results of the study may explain the mechanism of cognitive processing of emotion recognition impairment in the patient, and provide strong theoretical support for non-pharmaceutical intervention ns to the patients. Meanwhile, the study may also provide observation on Chinese patients as beneficial supplement in this field.

情绪识别能力变化很可能成为预测轻度认知障碍（MCI）及阿尔茨海默病（AD）患者社会功能衰退的关键因素，并成为早期干预的新“靶点”。前期研究仅揭示其基本表现形式。我们尚不清楚：（1）为何患者对正性和负性情绪的识别损害出现先后及程度不一致？（2）患者情绪识别是否具有特异性加工机制？是否受其他认知因素影响和调节？基于前期功能影像学及情绪认知心理学相关研究，本项目提出新假设：患者的空间工作记忆和选择性注意受损以及情绪效价本身可能通过改变知觉负荷、注意窗口及注意偏向对情绪识别进行影响和调节。本项目利用事件相关电位技术在揭示情绪认知加工时间进程方面的优势，结合情绪认知心理学实验范式操纵知觉负荷（高、低负荷）、注意窗口（聚焦式、分散式）、注意资源（有效、无效线索）进行验证。研究结果可为MCI及AD患者情绪识别障碍的成因及早期非药物干预提供有力的理论支持，并为该领域补充来自中国MCI和AD患者的观察数据。

面孔情绪识别能力的选择性损害，已被证实与神经系统退行性疾病有关。大量行为学研究发现，老年人负性情绪识别正确率下降，而正性情绪识别则相对保留。本研究利用事件相关电位技术在揭示情绪认知加工时间进程方面的优势探讨了：（1）年龄相关面孔情绪加工的神经动力学改变及其与认知功能的关系；（2）注意窗口（聚焦式、分散式）和知觉负荷（高、低）对老年人面孔情绪加工的潜在调节机制；以及（3）MCI及AD患者面孔情绪识别的行为学改变。本研究发现：（1）老年人对负性情绪面孔结构编码困难，正性面孔结构编码则相对完整，VPP及N170振幅与老年人负性情绪识别正确率密切相关；在执行面孔情绪分类任务时，两年龄组可能募集不同的神经网络，采用不同的情绪面孔加工策略；认知功能在老年人负性面孔情绪分类能力改变中扮演重要角色，老化很可能是编码和识别面孔情绪的潜在脆弱性特征。（2）老年人在情绪面孔早期加工的注意指向及结构编码阶段仅受视觉窗口调节，二阶构型和后期加工则受知觉负荷和视觉窗口共同调节。老年人对情绪面孔有整体加工倾向（分散视窗），聚焦视窗有利于老年人对负性情绪面孔的结构编码增强。（3）与老年对照相比，老年痴呆患者对正性和中性面孔情绪的识别能力显著下降，轻度认知障碍患者对中性情绪面孔的情绪识别能力显著下降。进一步研究将有助于探索面孔情绪识别能力改变对轻度认知障碍（老年痴呆临床前期）高风险个体的早期筛查及其认知功能损害的预测。