Interestingly, the emotional effects for chromesthetes were as strong as those for non-chromesthetes on some dimensions (happy/sad, active/passive and strong/weak), but weaker on others (calm/agitated and angry/not-angry).

The fact that chromesthetes exhibit emotional effects at all suggests that music-to-color synesthesia depends, at least in part, on neural connections that include emotion-related circuits in the brain. That they’re decidedly weaker in chromesthetes than non-chromesthetes for some emotions further suggests that chromesthetic experiences also depend on direct, non-emotional connections between the auditory and visual cortex.

Musical Anthropomorphism

The fact that music-to-color associations are so strongly influenced by emotion raises further questions. For example, why is it that fast, loud, high-pitched music “sounds” angry, whereas slow, quiet, low-pitched music “sounds” calm?

We don’t know the answers yet, but one intriguing possibility is what we like to call “musical anthropomorphism” – the idea that sounds are emotionally interpreted as being analogous to the behavior of people.

For example, faster, louder, high-pitched music might be perceived as angry because people tend to move and speak more quickly and raise their voices in pitch and volume when they’re angry, while doing the opposite when they’re calm. Why music in a major key sounds happier than music in a minor key, however, remains a mystery.

Artists and graphic designers can certainly use these results when they’re creating light shows for concerts or album covers for bands – so that “listening” to music can become richer and more vivid by “seeing” and “feeling” it as well.

But on a deeper level, it’s fascinating to see how effective and efficient the brain is at coming up with abstract associations.

To find connections between different perceptual events – such as music and color – our brains try to find commonalities. Emotions emerge dramatically because so much of our inner lives are associated with them. They are central not only to how we interpret incoming information, but also to how we respond to them.

Given the myriad connections from perceptions to emotions and from emotions to actions, it seems quite natural that emotions emerge so strongly – and perhaps unconsciously – in finding the best colors for a song.

Stephen Palmer is Professor of the Graduate School at University of California, Berkeley and Karen B Schloss is Assistant Professor of Research at Brown University This article was originally published on The Conversation. Read the original article.

Every Song Has a Color – and an Emotion – Attached to It