Component processes of human face perception in typical and atypical individuals

面孔感知是人类社会交往的重要组成部分。它指导我们如何与他人互动，使我们能够识别个人，识别他们的情绪状态，并判断他们的吸引力和可信度。因为面孔感知是如此毫不费力和可靠，所以我们很少再考虑它。但事实上，人脸感知和识别是基于复杂和鲜为人知的机制的困难成就。只有在遇到没有任何一般知觉或智力障碍，也没有任何神经损伤史的人时，人脸处理的真正困难才会显现出来，这些人发现很难从他们的脸中识别家人和朋友。我们和其他小组对人脸加工各个方面的行为测试表明，这些患有发育性面孔失认症(DP)的人中，许多人在物体识别方面没有类似的问题，这表明人脸和非人脸物体是由不同的机制加工的。所有的DPS都显示出身份加工的严重缺陷，但面孔加工的其他方面，如对面孔部分和面孔形状的感知，或情绪面孔表情的加工，可能是完整的或受损的，这表明DP是一种异质性疾病。在我们目前由ESRC资助的研究项目中，我们使用行为和电生理测量(事件相关脑电位，ERPs)的组合来获得关于面孔加工的哪些方面在DP中受到损害的新见解。到目前为止，我们的结果表明，人脸处理的早期视觉感知阶段是影响DP患者的人脸识别问题的主要原因。例如，面孔知觉完好的人处理直立面孔和倒置面孔的过程非常不同，这被解释为对直立面孔的感知是“配置的”或“整体的”，而反转面孔的处理方式则是不同的“基于部分”的方式。我们发现，DP患者没有表现出直立和倒置面孔之间的典型加工差异，这表明他们以结构/整体的方式加工直立面孔的能力没有得到正常发展。为了更准确地了解DPS和面孔加工完好的人之间的面孔感知差异，我们将进行一系列实验，使用专门设计用于参与面孔处理的不同方面的面孔和非面孔刺激(例如，对眼睛等突出脸部的感知、面部配置的处理、从不同角度感知面孔、使用面孔感知来记忆个别面孔)，以找出DP患者的哪些过程正常运行，哪些过程受损。我们还将研究DPS和非受损的人看脸的方式是否不同，以及他们在试图识别人脸时是否使用了不同的面部部位。找出面孔知觉的哪些方面在DPS中工作良好，哪些方面受到损害，对于我们理解面部加工能力完整的人的面孔感知机制具有重要意义。这也将极大地扩大我们对为什么有些人在人脸识别方面存在严重缺陷的了解。这样的赤字可能会对他们的社交生活产生巨大影响。由于感觉受到冷落，许多人很难维持友谊，他们在工作中的认知困难可能会非常令人担忧。

Face perception is an essential component of human social interaction. It guides how we interact with others by enabling us to recognize individuals, identify their emotional state, and judge their attractiveness and trustworthiness. Because face perception operates so effortlessly and reliably, we rarely give it a second thought. But in fact, face perception and recognition are difficult achievements that are based on complex and poorly understood mechanisms. The real difficulty of face processing only becomes apparent when meeting people without any general perceptual or intellectual impairment, and without any history of neurological damage, who find it extremely hard to recognize family and friends from their faces. Behavioural tests of various aspects of face processing conducted by us and by other groups have shown that many of these people with developmental prosopagnosia (DP) have no comparable problems with object recognition, which indicates that faces and non-face objects are processed by different mechanisms. All DPs show severe deficits in the processing of identity, but other aspects of face processing, such as the perception of face parts and face configurations or the processing of emotional facial expression, can be intact or impaired, suggesting that DP is a heterogeneous condition. In our current ESRC-funded research project, we use a combination of behavioural and electrophysiological measures (event-related brain potentials, ERPs) to gain new insights into which aspects of face processing are damaged in DP. Our results so far point to early visual-perceptual stages of face processing as a major cause of the face recognition problems that affect individuals with DP. For example, people with intact face perception process upright faces and inverted faces very differently, which is interpreted as evidence that the perception of upright faces is "configural" or "holistic", whereas inverted faces are processed in a qualitatively different "part-based" fashion. We have found that people with DP do not show these typical processing differences between upright and inverted faces, indicating that their ability to process upright faces in a configural/holistic fashion did not develop properly. To find out more precisely how face perception differs between DPs and people with intact face processing, we will conduct a series of experiments with face and non-face stimuli that are specifically designed to engage different aspects of face processing (e.g., the perception of salient face parts such as the eyes, the processing of facial configurations, perceiving faces from different viewpoints, using face perception to remember individual faces), to find out which processes operate normally and which are impaired in people with DP. We will also study whether DPs and non-impaired people look at faces differently, and whether they use different parts of a face when trying to identify it. Finding out which aspects of face perception work well and which are impaired in DPs will have important implications for our understanding the mechanisms that underlie face perception in people with intact face processing abilities. It will also greatly expand our knowledge of why some people have severe deficits in face recognition. Such deficits can have an enormous impact on their social lives. Many have difficulty maintaining friendships due to perceived snubs and their recognition difficulties at work can be extremely troubling.