基于合成平均刺激的平均表征机制——来自平均面孔吸引力的证据

人类能够快速提取集合中的统计信息,形成平均表征。对于平均表征的产生机制,研究者提出整合集合成员以合成平均刺激,或计算集合成员特征值的平均值两种观点。以往研究中合成的平均刺激的特征值和计算成员特征值的平均值两种方式的结果相似,难以区分两种观点。由于多个面孔的吸引力评分的均值与用这些面孔合成的平均面孔的吸引力评分存在差异,本研究使用经典的平均辨别任务(实验1和2)和吸引力评价任务(实验3和4)为平均表征的产生来源于合成平均刺激的观点提供了支持证据。4个实验分别采用大容量面孔集合和小容量面孔集合探讨平均表征的形成机制,结果发现大、小集合都形成了平均刺激,并且平均表征的评定和加工可能更多依赖合成的平均刺激,而非简单的对成员特征值进行平均;此外,集合吸引力出现了高评现象,但小集合高评现象更少出现,说明平均刺激的作用受到集合大小的影响。本研究为集合平均表征的形成机制和面孔集合吸引力高评现象的产生机制提供了新证据。     

面孔吸引力的整体表征及其动态性增强

面孔作为一种高级的视觉刺激,在人际交往中有着无可替代的作用。其中,面孔吸引力更是影响着日常生活的重要社交决策,如择偶、交友、求职、社会交换等。长久以来,研究者们从面孔特征、社会信息和观察者因素等角度不断探索着人们对静态面孔吸引力的感知,且多从进化角度加以解释。但是,人们如何表征面孔吸引力以及其动态性增强机制仍未可知。本项目通过两个研究,分别从面孔吸引力的整体表征,以及面孔动态性通过影响整体加工、影响对整体信息和特征信息的注意、以及影响社会信息来增强吸引力,从这两个角度尝试回答这一问题。在研究1中,本项目从整体加工的角度探索了面孔吸引力的认知表征。研究1.1通过评分任务和适应范式探索高空间频率（更多局部特征）和低空间频率（更多整体特征）对面孔吸引力的影响,旨在从空间频率探讨面孔吸引力的整体表征。研究1.2通过操纵面孔对称性和面孔常态性探索面孔常态性在面孔对称性和面孔吸引力间的中介作用,探讨面孔吸引力的常态构型表征。研究1.3引入“三庭五眼”这一中国传统面孔审美理论,通过评分任务和适应范式研究“三庭五眼” 构型是否符合中国人对高吸引力中国面孔的表征,以此探讨面孔吸引力的整体表征。研究1.4通过评分任务和适应范式考察局部面孔遮挡是否促进整体面孔吸引力,以及这种促进作用是否由于人们通过局部特征“脑补”出了完整面孔。研究2从整体加工、注意和生命力的角度探讨面孔吸引力的动态性增强机制。研究2.1使用合成效应范式测量动态面孔吸引力的整体加工,探索动静态面孔的吸引力差异是否源于其整体加工程度的不同。研究2.2使用注意分散范式,并结合眼动技术,探讨人们对动静态面孔的注视模式是否存在差异,这种差异是否能解释动态面孔吸引力的增强。研究2.3结合问卷法、实验法和结构方程模型,考察了生命力这一社会因素对动静态面孔吸引力的影响。本项目探讨了面孔吸引力的认知表征以及其动态性增强机制,有助于我们进一步理解人们对面孔吸引力的认知加工以及人类欣赏美这一高级智能。同时,本项目的结果对于日常人际交往和面孔吸引力相关算法的优化等方面也有潜在的应用价值。     

新生儿面孔识别中的两种偏好现象

面孔偏好和吸引力偏好是新生儿（0~1个月）面孔识别中两种重要的偏好现象。面孔偏好（face preference）是指呈现面孔和非面孔刺激时个体偏好面孔的现象;吸引力偏好（attractiveness preference）是指呈现面孔刺激时个体偏好有吸引力面孔的现象。文章从行为研究和原因探析两个方面对新生儿面孔偏好和吸引力偏好的研究概况进行了介绍,认为主体、客体、环境三方面都在不同程度上影响着新生儿的面孔识别行为,指出未来的研究还应在实验对象、实验材料等方面进一步努力。     

面孔方位对返回抑制的影响

采用辨别任务探讨了正立与倒立的中性面孔线索对返回抑制的影响。实验一采用同时线索化范式考察了正立与倒立面孔线索对靶刺激反应的影响,结果发现,两种面孔线索对随后靶刺激的反应没有影响。实验二采用单线索范式考察正立与倒立面孔对返回抑制的影响,结果发现,两种线索条件下均产生了返回抑制,而且返回抑制量没有显著差异。实验三,正立与倒立面孔作为靶刺激呈现,得到与实验二相同的结果。这些结果表明当采用中性面孔为线索时,返回抑制的产生并不受线索与靶刺激显著性的影响,而且返回抑制这种盲目机制不受任务难度的影响。     

人类嗓音加工的神经机制——来自正常视力者和盲人的脑神经证据

人类嗓音作为听觉环境的重要组成部分, 包含了大量副语言信息以帮助识别个体身份, 尤其对于盲人而言, 视觉面孔经验的缺乏使得嗓音信息成为其感知对方个体特征的主要来源。通过结合正常视力者和盲人在嗓音选择性加工和嗓音身份加工方面的研究, 尝试揭示普遍的人类嗓音加工模式以及盲人特异的嗓音加工机制。此外, 与视觉面孔加工相关的梭状回脑区也参与并卷入了两类人群的嗓音加工任务, 以此为基础梳理的视听整合模型和基于去掩蔽效应的跨模态重组假说, 为这两类人群嗓音加工神经基础的差异性提供了相应的解释机制, 未来研究希望可以进一步探究盲人的嗓音加工策略, 以及考察左侧颞上沟/回脑区在嗓音加工中的作用。     

婴幼儿面孔注意偏向：先天倾向与发展轨迹——来自正常和孤独症婴幼儿的证据

正常发展(Typically developing, TD)婴儿的先天面孔注意倾向稳定地存在于不同发展阶段不同刺激情景中, 且在生命第一年内呈现短暂下降后快速增强的发展趋势。TD婴幼儿的视觉注意在第4至6周之间发生由皮下控制向皮层控制的关键性转变之后, 伴随面孔视觉经验的不断积累, 逐渐形成的面孔特异性皮层网络对面孔的优先选择性反应逐渐增强。而孤独症谱系(Autism Spectrum Disorder, ASD)婴幼儿具备初始的面孔注意先天倾向, 但在面孔皮层发育关键期内逐渐偏离正常轨道, 在1岁左右表现出面孔注意障碍。该群体先天的感知注意损伤或社会动机缺失可能导致其在关键性转变期内的面孔视觉经验输入不足, 进而阻碍面孔特异性皮层网络的正常发展。未来研究可考虑采用生物遗传学方法和近红外脑成像技术探索新生儿面孔注意先天倾向的起源, 系统考察社会场景中感知觉特征和社会性特征对ASD高危婴儿面孔注意发展轨迹尤其是关键性转变期的影响作用。     

面孔吸引力同化的连续性效应

以往研究表明目标面孔的吸引力评价会偏向背景面孔, 产生同化效应。但同化效应的计算常常是对不同背景下目标面孔吸引力评分进行比较, 并没有考虑目标面孔单独呈现时的吸引力评分, 可能是虚假的同化效应。本文以单独呈现的目标面孔吸引力评分作为基准值计算同化效应, 考察了呈现时间和目标与背景面孔吸引力的差异对目标面孔吸引力评价的影响。结果发现, 个体对目标面孔吸引力的评分会偏向背景面孔的吸引力, 并表现出同化的连续性效应, 即目标和背景面孔的吸引力差异越大, 同化效应越小。     

面孔性别辨认中返回抑制效应的性别差异

采用线索-靶子实验范式, 要求被试完成面孔性别辨认任务, 从注意定向方面探讨面孔性别靶刺激返回抑制效应的性别差异。结果显示有效线索位置上面孔性别靶刺激的反应时均显著长于无效线索位置上的面孔性别靶刺激的反应时, 即表现出明显的返回抑制效应。进一步分析显示, 男性被试对同性和异性面孔靶刺激的返回抑制量无显著差异, 表明男性对面孔刺激的返回抑制不受面孔性别的影响; 而卵泡期女性对异性面孔靶刺激的返回抑制量显著小于黄体期女性, 表明女性对面孔靶刺激的返回抑制量与面孔性别和生理周期的交互作用有关。这些结果再一次为返回抑制的盲目机制提供了部分实验证据, 同时我们推测面孔性别对返回抑制的影响可能依赖于观察者对性信息的敏感性。     

不同情绪载体的神经活动及其异同——脑成像研究的ALE元分析

情绪识别一直是学界关注的热点。虽然已有研究探讨了动态面孔表情、动态身体表情和声音情绪的脑机制, 但对每种情绪载体的整体认识相对不完善, 同时对不同情绪载体之间神经机制的共性和区别知之甚少。因此, 本研究首先通过三项独立的激活似然估计元分析来识别每种情绪模式的大脑激活区域, 然后进行对比分析以评估三种情绪载体之间共同的和独特的神经活动。结果显示, 动态面孔表情的大脑活动包括广泛的额叶、枕叶、颞叶和部分顶叶皮层以及海马、小脑、丘脑、杏仁核等皮层下区域; 动态身体表情的激活集中于颞/枕叶相关脑区以及小脑和海马; 声音情绪则引起了颞叶、额叶、杏仁核、尾状核和脑岛的激活。联合分析表明, 三种情绪载体跨模态激活了左侧颞中回和右侧颞上回。对比分析的结果证明了视觉刺激比听觉刺激更占优势, 动态面孔表情尤为突出, 同时动态身体表情也发挥着重要作用, 但声音情绪有其独特性。总之, 这些发现验证和拓展了三种情绪载体的现有神经模型, 揭示了情绪处理中心的、普遍性的区域, 但每种情绪载体又有自己可靠的特异性神经回路。     

面孔吸引力观察者参照:“角度效应”的眼动研究

以标准的黑白面孔图片作为实验材料,让41名大学生观看不同倾斜角度(左倾、竖直和右倾)的面孔图片,并对之进行面孔吸引力的评价,同时用眼动仪记录被试的眼动数据。结果显示:(1)被试观看左倾和右倾面孔的平均瞳孔大小显著小于观看竖直面孔的平均瞳孔大小,观看左倾面孔的平均瞳孔大小显著大于右倾面孔;(2)被试对左倾和右倾面孔的平均注视时间显著短于对竖直面孔的平均注视时间,同时对左倾面孔的注视时间显著长于右倾面孔;(3)被试对左倾和右倾面孔的平均注视次数显著少于对竖直面孔的平均注视次数。实验结果表明,面孔的倾斜角度很可能是影响面孔吸引力的一个重要因素,在面孔吸引力的审美偏好中存在"角度效应",即竖直面孔的吸引力高于倾斜面孔的吸引力,左倾面孔的吸引力高于右倾面孔的吸引力。     

Something to smile about: The interrelationship between attractiveness and emotional expression

Previous studies have suggested a link between the processing of the emotional expression of a face and how attractive it appears. In two experiments we investigated the interrelationship between attractiveness and happiness. In Experiment 1 we presented morphed faces varying in attractiveness and happiness and asked participants to choose the more attractive of two simultaneously presented faces. In the second experiment we used the same stimuli as in Experiment 1 and asked participants to choose the happier face. The results of Experiment 1 revealed that the evaluation of attractiveness is strongly influenced by the intensity of a smile expressed on a face: A happy facial expression could even compensate for relative unattractiveness. Conversely, the findings of Experiment 2 showed that facial attractiveness also influences the evaluation of happiness: It was easier to choose the happier of two faces if the happier face was also more attractive. We discuss the interrelationship of happiness and attractiveness with regard to evolutionary relevance of positive affective status and rewarding effects.     

Dissociating averageness and attractiveness: attractive faces are not always average

Although the averageness hypothesis of facial attractiveness proposes that the attractiveness of faces is mostly a consequence of their averageness, 1 study has shown that caricaturing highly attractive faces makes them mathematically less average but more attractive. Here the authors systematically test the averageness hypothesis in 5 experiments using both rating and visual adaptation paradigms. Visual adaptation has previously been shown to increase both preferences for previously viewed face types (i.e., attractiveness) and their perceived normality (i.e., averageness). The authors used a visual adaptation procedure to test whether facial attractiveness is dependent upon faces' proximity to average (averageness hypothesis) or their location relative to average along an attractiveness dimension in face space (contrast hypothesis). While the typical pattern of change due to visual adaptation was found for judgments of normality, judgments of attractiveness resulted in a very different pattern. The results of these 5 experiments conclusively support the proposal that there are specific nonaverage characteristics that are particularly attractive. The authors discuss important implications for the interpretation of studies using a visual adaptation paradigm to investigate attractiveness.     

Why are average faces attractive? The effect of view and averageness on the attractiveness of female faces

Images of faces manipulated to make their shapes closer to the average are perceived as more attractive. The influences of symmetry and averageness are often confounded in studies based on full-face views of faces. Two experiments are reported that compared the effect of manipulating the averageness of female faces in profile and full-face views. Use of a profile view allows a face to be ”morphed“ toward an average shape without creating an image that becomes more symmetrical. Faces morphed toward the average were perceived as more attractive in both views, but the effect was significantly stronger for full-face views. Both full-face and profile views morphed away from the average shape were perceived as less attractive. It is concluded that the effect of averageness is independent of any effect of symmetry on the perceived attractiveness of female faces.     

The role of symmetry in attraction to average faces

Although many studies have demonstrated that average faces tend to be attractive, few studies have examined the extent to which symmetry contributes to the attractiveness of average faces. Such studies are potentially important, however, because average faces are highly symmetric and increasing the symmetry of face images increases their attractiveness. Here we demonstrate that increasing averageness of 2-D face shape independently of symmetry is sufficient to increase attractiveness, indicating that preferences for symmetry cannot solely explain the attractiveness of average faces. Additionally, we show that averageness preferences are significantly weaker when the effects of symmetry are controlled for using computer graphic methods than when the effects of symmetry are not controlled for, suggesting that symmetry contributes to the attractiveness of average faces. Importantly, this latter finding was not explained by the greater perceived similarity between versions offaces that varied in averageness, but not symmetry, than between versions of faces that varied in both averageness and symmetry.     

Dominance of texture over shape in facial identity processing is modulated by individual abilities

For face recognition, observers utilize both shape and texture information. Here, we investigated the relative diagnosticity of shape and texture for delayed matching of familiar and unfamiliar faces (Experiment 1) and identifying familiar and newly learned faces (Experiment 2). Within each familiarity condition, pairs of 3D‐captured faces were morphed selectively in either shape or texture in 20% steps, holding the respective other dimension constant. We also assessed participants’ individual face‐processing skills via the Bielefelder Famous Faces Test (BFFT), the Glasgow Face Matching Test, and the Cambridge Face Memory Test (CFMT). Using multilevel model analyses, we examined probabilities of same versus different responses (Experiment 1) and of original identity versus other/unknown identity responses (Experiment 2). Overall, texture was more diagnostic than shape for both delayed matching and identification, particularly so for familiar faces. On top of these overall effects, above‐average BFFT performance was associated with enhanced utilization of texture in both experiments. Furthermore, above‐average CFMT performance coincided with slightly reduced texture dominance in the delayed matching task (Experiment 1) and stronger sensitivity to morph‐based changes overall, that is irrespective of morph type, in the face identification task (Experiment 2). Our findings (1) show the disproportionate importance of texture information for processing familiar face identity and (2) provide further evidence that familiar and unfamiliar face identity perception are mediated by different underlying processes.     

Average faces are average faces

Photographs of faces of young adult male and female Scots were measured on nineteen frontal dimensions. Measures in each dimension were converted to z-scores and summed for each face. For each sex, the ten faces closest to the average summed z-score and the ten most distant from it were rated for attractiveness by white male and female New Zealand undergraduates. Raters agreed significantly in ordering the faces in attractiveness, but did not rate faces close to the “population” average differently from those distant from it. Tested for the first time with actual rather than contrived faces, the commonly reported hypothesis that faces representing the average of a population are attractive is not supported.     

Average faces are average faces

Photographs of faces of young adult male and female Scots were measured on nineteen frontal dimensions. Measures in each dimension were converted to z-scores and summed for each face. For each sex, the ten faces closest to the average summed z-score and the ten most distant from it were rated for attractiveness by white male and female New Zealand undergraduates. Raters agreed significantly in ordering the faces in attractiveness, but did not rate faces close to the “population” average differently from those distant from it. Tested for the first time with actual rather than contrived faces, the commonly reported hypothesis that faces representing the average of a population are attractive is not supported.     

Evidence for a young adult face bias in accuracy and consensus of age estimates

Adults' face processing may be specialized for the dimensions of young adult faces. For example, young and older adults exhibit increased accuracy in normality judgments and greater agreement in attractiveness ratings for young versus older adult faces. The present study was designed to examine whether there is a similar young adult face bias in facial age estimates. In Experiment 1, we created a face age continuum by morphing an averaged young adult face with an averaged older adult face in 5% increments, for a total of 21 faces ranging from 0 to 100% old. Young and older adults estimated facial age for three stimulus age categories [young (morphs 0–30%), middle‐aged (morphs 35–65%), and older adult (morphs 70–100%)]. Both age groups showed the least differentiation in age estimates for young adult faces, despite showing greater consensus across participants in estimates for young faces. In Experiment 2, young and older adults made age estimates for individual young and older adult identities. Both age groups were more accurate and showed greater consensus in age estimates for young faces. Collectively, these results provide evidence for a bias in processing young adult faces beyond that which is often observed in recognition and normality/attractiveness judgment tasks.     

Computer graphic studies of the role of facial similarity in judgements of attractiveness

Anecdotally, spouses are often said to resemble one another. This study investigates the effects of similarity between participants and stimuli on judgements of facial attractiveness: does “like prefer like”? Using computer graphic techniques, opposite sex facial stimuli were generated from subjects' photographs. Experiment 1 showed a correlation between attractiveness and similarity but the effect can be explained by the attractiveness of average faces. Beyond this, there was a trend for individual subjects to rate opposite sex images with a similar face shape to their own face as more attractive than other subjects. Experiment 2 allowed subjects to interactively manipulate an opposite sex facial image along a continuum from a self-similar shape, through an average face shape, to a face with opposite characteristics. No significant preferences for self-similar or opposite characteristics were found. Preferences for average faces are stronger than preferences for self-similar faces.     

Computer graphic studies of the role of facial similarity in judgements of attractiveness

Anecdotally, spouses are often said to resemble one another. This study investigates the effects of similarity between participants and stimuli on judgements of facial attractiveness: does “like prefer like”? Using computer graphic techniques, opposite sex facial stimuli were generated from subjects' photographs. Experiment 1 showed a correlation between attractiveness and similarity but the effect can be explained by the attractiveness of average faces. Beyond this, there was a trend for individual subjects to rate opposite sex images with a similar face shape to their own face as more attractive than other subjects. Experiment 2 allowed subjects to interactively manipulate an opposite sex facial image along a continuum from a self-similar shape, through an average face shape, to a face with opposite characteristics. No significant preferences for self-similar or opposite characteristics were found. Preferences for average faces are stronger than preferences for self-similar faces.