Mash Joanna, Jenkinson Paul M, Dean Charlotte E, Laws Keith R
School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK.
School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK; ISN Psychology, Institute for Social Neuroscience, Melbourne, Australia.
Conscious Cogn. 2023 Mar;109:103480. doi: 10.1016/j.concog.2023.103480. Epub 2023 Feb 8.
Strange face illusions describe a range of visual apparitions that occur when an observer gazes at their image reflected in a mirror or at another person's face in a dimly lit room. The illusory effects range from mild alterations in colour, or contrast, to the perception of distorted facial features, or new strange faces.The current review critically evaluates studies investigating strange face illusions, their methodological quality, and existing interpretations.
Searches conducted using Scopus, PubMed, ScienceDirect and the grey literature until June 2022 identified 21 studies (N = 1,132; healthy participants n = 1,042; clinical participants n = 90) meeting the inclusion criteria (i.e., providing new empirical evidence relating to strange face illusions). The total sample had a mean age of 28.3 years (SD = 10.31) and two thirds (67 %) of participants tested to date are female. Results are reported using the Preferred Reporting Items for Systematic Reviews and meta-Analyses (PRISMA) guidelines. The review was preregistered at the Open Science Framework (OSF: https://osf.io/ek48d).
Pooling data across studies, illusory new strange faces are experienced by 58% (95%CI 48 to 68) of nonclinical participants. Study quality as assessed by the Appraisal Tool for Cross-Sectional Studies (AXIS) revealed that 3/21 (14.28%) studies were rated as high, 9/21 (42.86%) as moderate and 9/21 (42.86%) as low quality. Whilst the items relating specifically to reporting quality scored quite highly, those relating to study design and possible biases were lower and more variable. Overall, study quality accounted for 87% of the variance in reporting rates for strange faces, with higher quality being associated with lower illusion rates. The prevalence of illusions was also significantly greater in samples that were older, had higher proportions of female participants and for the interpersonal dyad (IGDT) compared to the mirror gaze paradigm (MGT). The moderating impact of study quality persisted in a multiple meta-regression involving participant age, paradigm type (IGDT vs MGT) and level of feature distortion. Our review point to the importance of reduced light levels, face stimuli and prolonged eye fixation for strange face illusions to emerge.
Strange face illusions reliably occur in both mirror-gazing and interpersonal gazing dyad paradigms. Further research of higher quality is required to establish the prevalence and particularly, the mechanisms underpinning strange face illusions.
怪脸错觉描述了一系列视觉幻象，当观察者凝视镜子中自己的影像或在昏暗房间里看另一个人的脸时就会出现。这些错觉效应范围从颜色或对比度的轻微变化，到对面部特征扭曲的感知，或者看到新的怪脸。本综述批判性地评估了调查怪脸错觉、其方法学质量和现有解释的研究。
使用Scopus、PubMed、ScienceDirect和灰色文献进行检索，直至2022年6月，共识别出21项符合纳入标准的研究（N = 1132；健康参与者n = 1042；临床参与者n = 90）（即提供与怪脸错觉相关的新实证证据）。总样本的平均年龄为28.3岁（标准差 = 10.31），迄今为止测试的参与者中有三分之二（67%）为女性。结果按照系统评价和Meta分析的首选报告项目（PRISMA）指南进行报告。该综述已在开放科学框架（OSF：https://osf.io/ek48d）上预先注册。
汇总各项研究的数据，58%（95%置信区间48至68）的非临床参与者体验到了虚幻的新怪脸。通过横断面研究评估工具（AXIS）评估的研究质量显示，21项研究中有3项（14.28%）被评为高质量，9项（42.86%）为中等质量，9项（42.86%）为低质量。虽然与报告质量相关的项目得分较高，但与研究设计和可能偏差相关的项目得分较低且更具变异性。总体而言，研究质量占怪脸报告率方差的87%，质量越高，错觉率越低。与镜像凝视范式（MGT）相比，在年龄较大、女性参与者比例较高的样本以及人际二元组（IGDT）中，错觉的患病率也显著更高。在涉及参与者年龄、范式类型（IGDT与MGT）和特征扭曲程度的多元Meta回归中，研究质量的调节作用依然存在。我们的综述指出了较低光照水平、面部刺激和长时间注视眼睛对于怪脸错觉出现的重要性。
怪脸错觉在镜像凝视和人际凝视二元组范式中均可靠出现。需要进行更高质量的进一步研究，以确定怪脸错觉的患病率，尤其是其背后的机制。
