Brain appears to organise emotions in a hexagonal grid

Neuroscientists at Emory University in the United States have found that the brain may organise emotions in a hexagonal grid, much as bees arrange honeycomb cells to store honey. The study, published in the scientific journal PLOS Biology, helps explain how the brain sorts information about emotional states.

Eighteen volunteers took part in the experiment. They were asked to rate facial expressions that portrayed various emotions, while researchers tracked their brain activity with functional magnetic resonance imaging (fMRI).

As participants' minds analysed emotional states, a hexagonal grid pattern appeared in a brain region called the ventromedial prefrontal cortex. The same pattern showed up when participants rated written phrases instead of facial expressions.

What it means

Because the pattern does not depend on the type of information, it suggests the brain encodes relationships between emotional concepts, rather than simply reacting to what a person sees. The authors suggest that a grid-like system could help the brain organise this information.

Scientists have long known that our understanding of emotions rests on a surprisingly orderly structure. However, how exactly the brain encodes that structure had remained a mystery until now. The new study offers one possible explanation, though the authors present it as a suggestion rather than a proven conclusion.