Have you ever noticed that death metal bands use spiky font but that romantic poetry is written in flowery curlicues? Is that a cultural accident? Or do shapes and sounds express energy in the same way? We found that shapes, sounds, human speech and movement, all convey emotional arousal in the same way. Specifically, variation in the central tendency of the frequency spectrum of a stimulus—its spectral centroid—is used by signal senders to express emotional arousal and by signal receivers to make emotional arousal judgements. Having a multi-sensory code allows us to efficiently estimate an agent’s level of emotional arousal.
We further demonstrate that this efficiency —and emotion perception more generally —is supported by the same representational structure in visual and auditory brain areas.