Perception of emotional expressions is independent of face selectivity in monkey inferior temporal cortex
Perception of emotional expressions is independent of face selectivity in monkey inferior temporal cortex
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DOI：
10.1073/pnas.0800489105
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发表时间：
2008-04-08
影响因子：
11.1
通讯作者：
Tootell, Roger B. H.
中科院分区：
文献类型：
--
作者：
Hadj-Bouziane, Fadila;Bell, Andrew H.;Tootell, Roger B. H.
感知和区分面部表情的能力对社会交流至关重要。在人类身上进行的大量功能性磁共振成像（fMRI）研究表明，杏仁核和视觉皮层对具有不同情感效价的面部会有增强的反应。然而，相对较少的研究探讨了效价如何影响猴子的神经反应，这限制了跨物种进行比较以及理解潜在神经机制的能力。在此，我们利用fMRI在三只清醒且行为正常的猴子身上测试了猕猴面部表情对这两个区域内神经激活的影响。猴子在注视中心的同时，呈现不同猕猴面部表情的组块。测试了四种不同的面部表情：（i）中性，（ii）攻击性（张嘴威胁），（iii）恐惧（恐惧露齿），（iv）顺从（咂嘴）。我们的研究结果证实，猴子的杏仁核和颞下回都受到面部表情的调节。与人类的fMRI研究结果一样，恐惧表情在猴子身上引起的反应最大——尽管人类和猕猴的恐惧表情在外观上并不相似。此外，我们发现效价效应在颞下回并非均匀分布。令人惊讶的是，这些效价图与两个相关的功能图无关：（i）“面部选择性”区域图（面部与非面部物体）和（ii）“面部反应性”区域图（面部与打乱的图像）。因此，面部感知和效价感知背后的神经机制似乎是不同的。
The ability to perceive and differentiate facial expressions is vital for social communication. Numerous functional MRI (fMR1) studies in humans have shown enhanced responses to faces with different emotional valence, in both the amygdala and the visual cortex. However, relatively few studies have examined how valence influences neural responses in monkeys, thereby limiting the ability to draw comparisons across species and thus understand the underlying neural mechanisms. Here we tested the effects of macaque facial expressions on neural activation within these two regions using fMR1 in three awake, behaving monkeys. Monkeys maintained central fixation while blocks of different monkey facial expressions were presented. Four different facial expressions were tested: (i) neutral, (it) aggressive (open-mouthed threat), (fil) fearful (fear grin), and (iv) submissive (lip smack). Our results confirmed that both the amygdala and the inferior temporal cortex in monkeys are modulated by facial expressions. As in human fMR1, fearful expressions evoked the greatest response in monkeys-even though fearful expressions are physically dissimilar in humans and macaques. Furthermore, we found that valence effects were not uniformly distributed over the inferior temporal cortex. Surprisingly, these valence maps were independent of two related functional maps: (i) the map of -"face-selective" regions (faces versus non-face objects) and (it) the map of "face-responsive" regions (faces versus scrambled images). Thus, the neural mechanisms underlyingface perception and valence perception appear to be distinct.