Zhao Dongfang, Shen Xiangnan, Li Shuaixia, He Weiqi
Research Center of Brain and Cognitive Neuroscience, Liaoning Normal University, Dalian 116029, China.
Key Laboratory of Brain and Cognitive Neuroscience, Liaoning Province, Dalian 116029, China.
Brain Sci. 2023 Dec 9;13(12):1699. doi: 10.3390/brainsci13121699.
Recognizing the emotions of faces in a crowd is crucial for understanding overall behavior and intention as well as for smooth and friendly social interactions. However, it is unclear whether the spatial frequency of faces affects the discrimination of crowd emotion. Although high- and low-spatial-frequency information for individual faces is processed by distinct neural channels, there is a lack of evidence on how this applies to crowd faces. Here, we used functional magnetic resonance imaging (fMRI) to investigate neural representations of crowd faces at different spatial frequencies. Thirty-three participants were asked to compare whether a test face was happy or more fearful than a crowd face that varied in high, low, and broad spatial frequencies. Our findings revealed that fearful faces with low spatial frequencies were easier to recognize in terms of accuracy (78.9%) and response time (927 ms). Brain regions, such as the fusiform gyrus, located in the ventral visual stream, were preferentially activated in high spatial frequency crowds, which, however, were the most difficult to recognize behaviorally (68.9%). Finally, the right inferior frontal gyrus was found to be better activated in the broad spatial frequency crowds. Our study suggests that people are more sensitive to fearful crowd faces with low spatial frequency and that high spatial frequency does not promote crowd face recognition.
识别一群人中面孔的情绪对于理解整体行为和意图以及进行顺畅友好的社交互动至关重要。然而，尚不清楚面孔的空间频率是否会影响对群体情绪的辨别。虽然个体面孔的高空间频率和低空间频率信息由不同的神经通道处理，但缺乏关于这如何适用于群体面孔的证据。在这里，我们使用功能磁共振成像（fMRI）来研究不同空间频率下群体面孔的神经表征。33名参与者被要求比较一张测试面孔与一张在高、低和宽空间频率上变化的群体面孔相比，是快乐的还是更恐惧的。我们的研究结果表明，低空间频率的恐惧面孔在准确性（78.9%）和反应时间（927毫秒）方面更容易识别。位于腹侧视觉通路的脑区，如梭状回，在高空间频率群体中被优先激活，然而，这些群体在行为上是最难识别的（68.9%）。最后，发现右侧额下回在宽空间频率群体中激活程度更高。我们的研究表明，人们对低空间频率的恐惧群体面孔更敏感，而高空间频率并不能促进群体面孔识别。
