Abstract:
This research explores early Event-Related Potentials (ERPs) sensitivity to facial stimuli, investigating various facial features aimed to unveil underlying neural mechanisms. Two experiments, each involving 15 undergraduate students, utilized a multidimensional stimulus set incorporating race, gender, age, emotional expression, face masks, and stimulus orientation. Findings highlight significant modulations in N170 and P200 amplitudes and latencies for specific attributes, replicating prior research and revealing novel insights. Notably, age-related facial feature variations, facial inversion, and the presence of face masks significantly impact neural responses. Several speculative explanations are proposed to elucidate these results: First, the findings lend support to the idea that the increased N170 amplitude observed with facial inversion is closely tied to the activation of object-sensitive neurons. This is further bolstered by a similar amplitude increase noted when masks (effective objects) are added to faces. Second, the absence of an additional amplitude increase, when inverting face images with face masks suggests that neural populations may have reached a saturation point, limiting further enhancement. Third, the study reveals that the latency deficit in N170 induced by facial inversion is even more pronounced in the subsequent ERP component, the P200, indicating that face inversion may impact multiple stages of face processing. Lastly, the significant increase in P200 amplitude, typically associated with face typicality, for masked faces in this study aligns with previous research that demonstrated elevated P200 amplitudes for scrambled faces. This suggests that obscured faces may be processed as typical, potentially representing a default state in face processing.
摘要:
这项研究探讨了早期事件相关电位(ERP)对面部刺激的敏感性,调查各种面部特征,旨在揭示潜在的神经机制。两个实验,每个涉及15名本科生,利用了一个包含种族的多维刺激集,性别,年龄,情感表达,口罩,和刺激取向。研究结果突出了特定属性的N170和P200振幅和延迟中的重要调制,复制先前的研究并揭示新颖的见解。值得注意的是,与年龄相关的面部特征变化,面部倒置,面罩的存在会显著影响神经反应。提出了几种推测性的解释来阐明这些结果:首先,这些发现支持了以下观点:面部倒置时观察到的N170振幅增加与对象敏感神经元的激活密切相关.当面罩(有效对象)被添加到面部时,这通过注意到的类似的幅度增加而进一步得到支持。第二,没有额外的振幅增加,当用面罩反转面部图像表明神经群体可能已经达到饱和点时,限制进一步增强。第三,研究表明,由面部倒置引起的N170潜伏期缺陷在随后的ERP组件中更加明显,P200,表明人脸反转可能会影响人脸处理的多个阶段。最后,P200振幅的显著增加,通常与面部典型性相关,对于本研究中的蒙面,与先前的研究一致,该研究证明了乱序面部的P200振幅升高。这表明模糊的面孔可以像典型的那样处理,可能表示面部处理中的默认状态。