Have you heard the metaphor, "my future's so bright, I've got to wear shades?"

Our guess is that you understood both the meaning, and humor behind the metaphor. However, people with damage to the angular gyrus region of their brains don't get metaphors. That is, they have trouble interpreting the figurative meaning of metaphors. All they can figure is the literal meaning of what they hear and read.

These people often come up with complex and elaborate explanations as to the literal meaning of phrases meant to be figurative. In this instance, a person with damage to the angular gyrus may interpret me as having meant that the depletion of the ozone layer is going to make it hotter and sunnier or something like that.

The angular gyrus is situated within the parietal lobe at the intersection of regions that process touch, hearing, and vision. The angular gyrus is more developed in humans than in other primates, and so V.S. Ramachandran, who conducted this research with colleagues, thinks it may have played a role of some significance in the evolution of our cognition. He explains it like this: "Any monkey can reach for a peanut, but only a human can reach for the stars or even understand what that means."