Derya Dilara, Kang June, Kwon Do-Young, Wallraven Christian
Department of Brain and Cognitive Engineering, Korea University, Seoul, South Korea.
Department of Neurology, Korea University Ansan Hospital, Korea University College of Medicine, Ansan-si, South Korea.
Front Psychol. 2019 Nov 14;10:2458. doi: 10.3389/fpsyg.2019.02458. eCollection 2019.
The question whether facial expression processing may be impaired in Parkinson's disease (PD) patients so far has yielded equivocal results - existing studies, however, have focused on testing expression processing in recognition tasks with static images of six standard, emotional facial expressions. Given that non-verbal communication contains both emotional and non-emotional, conversational expressions and that input to the brain is usually dynamic, here we address the question of potential facial expression processing differences in a novel format: we test a range of conversational and emotional, dynamic facial expressions in three groups - PD patients ( = 20), age- and education-matched older healthy controls ( = 20), and younger adult healthy controls ( = 20). This setup allows us to address both effects of PD and age-related differences. We employed a rating task for all groups in which 12 rating dimensions were used to assess evaluative processing of 27 expression videos from six different actors. We found that ratings overall were consistent across groups with several rating dimensions (such as arousal or outgoingness) having a strong correlation with the expressions' motion energy content as measured by optic flow analysis. Most importantly, we found that the PD group did not differ in any rating dimension from the older healthy control group (HCG), indicating highly similar evaluation processing. Both older groups, however, did show significant differences for several rating scales in comparison with the younger adults HCG. Looking more closely, older participants rated negative expressions compared to the younger participants as more positive, but also as less natural, persuasive, empathic, and sincere. We interpret these findings in the context of the positivity effect and in-group processing advantages. Overall, our findings do not support strong processing deficits due to PD, but rather point to age-related differences in facial expression processing.
帕金森病（PD）患者的面部表情处理是否会受损这一问题，目前尚无定论——然而，现有研究主要聚焦于使用六种标准情感面部表情的静态图像，在识别任务中测试表情处理能力。鉴于非语言交流包含情感和非情感的对话表情，且大脑接收的输入通常是动态的，在此我们以一种全新的形式探讨潜在的面部表情处理差异问题：我们对三组人群进行测试，包括帕金森病患者（n = 20）、年龄和教育程度匹配的老年健康对照组（n = 20）以及年轻成人健康对照组（n = 20），测试一系列对话和情感的动态面部表情。这种设置使我们能够探讨帕金森病的影响以及与年龄相关的差异。我们对所有组采用了一项评分任务，其中使用12个评分维度来评估来自六个不同演员的27个表情视频的评价处理。我们发现，总体评分在各组之间是一致的，有几个评分维度（如唤醒度或外向性）与通过光流分析测量的表情运动能量内容高度相关。最重要的是，我们发现帕金森病组在任何评分维度上与老年健康对照组（HCG）均无差异，表明评价处理高度相似。然而，与年轻成人HCG相比，两个老年组在几个评分量表上确实存在显著差异。进一步观察发现，与年轻参与者相比，老年参与者对负面表情的评分更高，但同时也认为这些表情不那么自然、有说服力、有同理心且真诚。我们在积极效应和群体内处理优势的背景下解释这些发现。总体而言，我们的研究结果不支持帕金森病导致严重处理缺陷的观点，而是指出面部表情处理存在与年龄相关的差异。
