Into the brain of a liar

The liars in Yang's study had on average 22 percent to 26 percent more white matter [axonal insulation] in their prefrontal cortex than both the normal and antisocial controls.
... brain scans of autistic people, who have difficulty telling lies, show the exact opposite profile of Yang's liars: They have less white matter than other people. In autistic children, white matter doesn't develop at a normal rate.