" And that both of these features are well predicted by the volume of gray matter in two specific regions of the prefrontal cortex, regions that are known to be important in "decoupling the perspectives of other people from one's own.

WSJ: The Social Network and the Dunbar Number | Mind & Matter

Liars, it turned out, had 14% less gray matter than the controls but had 22-26% more white matter in the prefrontal cortex, suggesting that they were more likely to make connections between different memories and ideas as increased connectivity means greater access to the reserve of associations and memories stored in gray matter.

FORBES: Do Liars Really Have Different Brains?