科研人员通过脑成像研究发现了乌鸦的记忆人脸能力背后的神经回路。John Marzluff及其同事此前证明了乌鸦拥有记住威胁性的或者中性的人的脸的不寻常能力，但是此前尚不清楚这种能力的神经基础。使用一种称为FDG-PET的脑成像技术——它测量经过标记的葡萄糖的吸收量，作为大脑活动的替代指标——这组作者报告说，当乌鸦看到此前在威胁性或关怀性环境下遇到的人脸的时候，大脑的不同区域会激活。由于乌鸦认为捕捉它们的人的脸是危险的，这组作者佩戴了面罩并且捕捉了12只成年雄性美洲乌鸦，并把它们养在笼子里4周时间，其间这些乌鸦由佩戴另一种面具的研究人员喂养，这意味着这些面具与提供照顾有联系。在这些乌鸦的俘获期的最后，这组作者对这些鸟类觉醒的大脑对这两种面具的响应进行了成像：看到捕捉它们的人的面具激活了这些乌鸦大脑中的与恐惧有关联的区域，而提供照顾的人佩戴的面具触发了与联想学习、动机和饥饿有关的区域。这组作者说，这些发现提示乌鸦能识别人脸，并把视觉线索与期望和情绪整合起来从而改变行为。（生物谷Bioon.com）
doi:10.1073/pnas.1206109109
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Brain imaging reveals neuronal circuitry underlying the crow’s perception of human faces
John M. Marzluff, Robert Miyaoka, Satoshi Minoshima and Donna J. Cross
Crows pay close attention to people and can remember specific faces for several years after a single encounter. In mammals, including humans, faces are evaluated by an integrated neural system involving the sensory cortex, limbic system, and striatum. Here we test the hypothesis that birds use a similar system by providing an imaging analysis of an awake, wild animal’ s brain as it performs an adaptive, complex cognitive task. We show that in vivo imaging of crow brain activity during exposure to familiar human faces previously associated with either capture (threatening) or caretaking (caring) activated several brain regions that allow birds to discriminate, associate, and remember visual stimuli, includ-ing the rostral hyperpallium, nidopallium, mesopallium, and lateral striatum. Perception of threatening faces activated circuitry includ-ing amygdalar, thalamic, and brainstem regions, known in humans and other vertebrates to be related to emotion, motivation, and conditioned fear learning. In contrast, perception of caring faces activated motivation and striatal regions. In our experiments and in nature, when perceiving a threatening face, crows froze and fixed their gaze (decreased blink rate), which was associated with activa-tion of brain regions known in birds to regulate perception, atten-tion, fear, and escape behavior. These findings indicate that, similar to humans, crows use sophisticated visual sensory systems to rec-ognize faces and modulate behavioral responses by integrating vi-sual information with expectation and emotion. Our approach has wide applicability and potential to improve our understanding of the neural basis for animal behavior.
