A team of researchers from the University of Southern Denmark in Odense says that it probably happens because the brain makes sense of gestures in the same way that as it processes language.
Lead researcher Kristian Tylen used fMRI to scan the brains of volunteers as they viewed pictures of everyday objects arranged to communicate meaning, such as flowers left on a doorstep, followed by the same objects in less meaningful settings, such as flowers growing in the wild.
The researchers observed that the symbolic arrangements prompted more activity in regions associated with verbal communication, such as the left fusiform gyrus, used in reading, and the inferior frontal cortex, linked to semantic meaning.
The team further saw that less conventional arrangements, like an art installation, also affected a "verbal" area, producing a pattern of brain activity previously associated with unusual verbal metaphors.
Studies conducted in the past have already shown that the brain processes body language and facial expressions in a similar way to verbal communication.
"It shows that language is more than just the processing of words - it pervades many of our activities," New Scientist quoted Tylen as saying.