We found that low-level percepts like spikiness predict high-level concepts like emotional arousal.  We demonstrated this finding in the US and in a remote village in Cambodia. This helps us understand how emotion can be conveyed without language and why death metal bands use spiky fonts.

Video abstract of this paper -- created by Beau Sievers.

This paper explains what spikiness means (spectral centroid) and how it provides a robust signal across sight and sound.

And this paper reveals the shared neural code in visual and auditory cortices underlying this efficient emotional signal.