System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan.
Department of Physiology, Vietnam Military Medical University, Ha noi 100000, Vietnam.
Cereb Cortex. 2018 Jun 1;28(6):2131-2145. doi: 10.1093/cercor/bhx118.
Snakes and conspecific faces are quickly and efficiently detected in primates. Because the medial prefrontal cortex (mPFC) has been implicated in attentional allocation to biologically relevant stimuli, we hypothesized that it might also be highly responsive to snakes and conspecific faces. In this study, neuronal responses in the monkey mPFC were recorded, while monkeys discriminated 8 categories of visual stimuli. Here, we show that the monkey mPFC neuronal responses to snakes and conspecific faces were unique. First, the ratios of the neurons that responded strongly to snakes and monkey faces were greater than those of the neurons that responded strongly to the other stimuli. Second, mPFC neurons responded stronger and faster to snakes and monkey faces than the other categories of stimuli. Third, neuronal responses to snakes were unaffected by low-pass filtering of the images. Finally, activity patterns of responsive mPFC neurons discriminated snakes from the other stimuli in the second 50 ms period and monkey faces in the third period after stimulus onset. These response features indicate that the mPFC processes fast and coarse visual information of snakes and monkey faces, and support the hypothesis that snakes and social environments have shaped the primate visual system over evolutionary time.
蛇类和同种面孔在灵长类动物中能够被快速有效地检测到。由于内侧前额叶皮层（mPFC）与生物相关刺激的注意力分配有关，我们假设它可能也对蛇类和同种面孔高度敏感。在这项研究中，记录了猴子 mPFC 中的神经元反应，同时猴子对 8 种视觉刺激进行了辨别。在这里，我们表明猴子 mPFC 神经元对蛇类和同种面孔的反应是独特的。首先，对蛇类和猴子面孔反应强烈的神经元比例大于对其他刺激反应强烈的神经元比例。其次，mPFC 神经元对蛇类和猴子面孔的反应比其他类别的刺激更强更快。第三，对蛇类的神经元反应不受图像低通滤波的影响。最后，反应性 mPFC 神经元的活动模式在刺激后 50 毫秒的第二期和第三期将蛇类与其他刺激区分开来，在第三期将猴子面孔与其他刺激区分开来。这些反应特征表明，mPFC 处理蛇类和猴子面孔的快速粗略视觉信息，并支持这样的假设，即蛇类和社会环境在进化过程中塑造了灵长类动物的视觉系统。
