Burns Edwin J, Martin Joel, Chan Alice H D, Xu Hong
Division of Psychology, School of Social Sciences, Nanyang Technological University, Singapore.
Department of Psychology, Swansea University, UK.
Neuropsychologia. 2017 Jul 28;102:217-228. doi: 10.1016/j.neuropsychologia.2017.06.020. Epub 2017 Jun 23.
Developmental prosopagnosia (DP) is associated with severe, lifelong deficits in face recognition, with such cases often cited as support for a dissociation between the processing of facial identity and emotion. Here we examine the evidence against this dissociation and propose that the processing of facial happiness, either with or without awareness, is actually integrated within the same neural network involved in facial identity recognition. We also test this hypothesis on a group of DP cases and neurotypical controls (NT) by adapting them to expressionless neutral faces, intact happy faces and hybrid faces. Despite these hybrid faces being explicitly identified as expressionless due to their higher spatial frequencies taken from a neutral face, their low spatial frequencies convey happy facial expressions that participants are unaware of. After adaptation, participants were asked to judge the facial expressions of face stimuli that were morphed incrementally in varying degrees of sad through to happy. Both groups exhibited emotion adaptation aftereffects to the intact happy faces, although this effect was smaller in DP. Whereas NT produced emotion adaptation aftereffects without awareness of the happy emotion in the hybrid faces; as a group, those with DP did not. Furthermore, our DP cases also exhibited deficits in judging the emotion of the happiest morphed test faces. Our results indicate that the processing of happy facial expressions, with or without awareness, is likely integrated within the face recognition network. We hypothesise that the previously identified abnormalities in the fusiform gyrus in those with DP is the most likely structure responsible for these deficits.
发展性面孔失认症（DP）与严重的、终身性的面孔识别缺陷相关，此类病例常被引用来支持面部身份与情绪加工之间的分离。在此，我们审视了反对这种分离的证据，并提出无论有无意识，对面部快乐表情的加工实际上是整合在参与面部身份识别的同一神经网络之中的。我们还通过让一组DP患者和神经典型对照组（NT）适应无表情的中性面孔、完整的快乐面孔和混合面孔，来检验这一假设。尽管这些混合面孔因其取自中性面孔的较高空间频率而被明确识别为无表情，但它们的低空间频率传达出参与者未意识到的快乐面部表情。适应之后，要求参与者判断从悲伤到快乐逐渐变形的面部刺激的表情。两组对完整的快乐面孔都表现出情绪适应后效，尽管DP组的这种效应较小。NT组在未意识到混合面孔中快乐情绪的情况下产生了情绪适应后效；而作为一个群体，DP患者则没有。此外，我们的DP患者在判断最快乐的变形测试面孔的情绪时也表现出缺陷。我们的结果表明，无论有无意识，对面部快乐表情的加工很可能整合在面孔识别网络之中。我们推测，先前在DP患者中发现的梭状回异常是造成这些缺陷的最可能结构。
