The following post is about AU1 – inner brow raiser, driven by the medial part of the frontalis muscle. It covers: 解剖学 变化, 普通 错误并提供 洁净 参考文献. 

 

我是什么眉毛提升器？

内提眉器。 或 AU1，是一个 面部动作编码系统 (FACS) action unit (AU). Its function is to raise the medial brow/forehead area, and its action is triggered by the contraction of the medial region of 额叶. It can difficult find clean references 眉头微皱 When building FACS references, many sources fail to:

1. Find actors who can voluntarily trigger their medial frontalis without also contracting the lateral area of frontalis or corrugator supercilii. 
2. 正确引导模型 to perform medial frontalis contraction.

In our everyday lives, most of us can effortlessly raise our inner brows without thinking twice; however, when commanded to, many people struggle to isolate this motion.

FACS 参考资料和错误信息

I recently (2020) critiqued a set of FACS shapes for a client and noticed his 眉弓 形状有一些波纹管（从 眉笔)错误地混入。

Client’s Inner Brow Blendshape + My Notes:

增加瓦楞机 眉弓 是一个非常常见的错误。这种共同性部分是由于： 好的参考资料很难找到!

Even my client – an established industry artist with a great portfolio and CV – unknowingly added corrugator features to his model, because he trusted a tainted reference. The reference he used was from a prominent anatomy and facial expression book: 脸部表情的解剖. Many art students and professionals use this textbook. It is a great textbook, but some of its FACS shapes are inaccurate.

Reference used by client:

See the vertical and wavy lines in the center of the forehead in the images below? Those vertical lines are from a brow knitting muscle known corrugator supercilii.

To view some clean examples of medial brow raising, observe the GIFs below. Read about the primary and secondary effects of 眉弓 以及其特点如何因人而异。

清洁 AU1 - 内提眉器示例

example i

example ii 

For more information 看 内涵式提眉术的秘密人生.

For a full and structured FACS deep dive, see my online course, the: FACS补习班.