July 22, 2009

Expressions trump bananas for chimps

A person is more likely to catch a chimp's attention through facial expressions than by bananas, a Japanese research team reported Wednesday.

The findings indicate chimps are as likely to respond in to faces in a similar manner as humans, researchers at the Primate Research Institute at Japan's Kyoto University said.

It is well known that faces are processed in a different manner from other types of complex visual stimuli, Japanese researchers Masaki Tomonaga and Tomoko Imura said in their paper. We've shown that chimps share this tendency to notice and pay attention to faces in preference to other objects.

In their study, the researchers found images of chimpanzee faces shown to their subjects attracted attention more effectively than bananas and other objects such as flowers, houses or trains. They also noted the effect was reduced when the faces were inverted, suggesting a specific configuration of an upright face caught the eye.

This attentional capture was also observed when upright human faces were presented, indicating that this effect is not limited to their own species, Tomonaga said.

The findings were described in BioMed Central's open-access journal, Frontiers in Zoology.