Liars often give themselves away by facial expressions or changes in vocal pitch.
Aphasics are clearly superior at perception of deception. That skill was suspected for a long time, but the new study is the first to prove it. The aphasics had suffered damage to language centers on the left side of their brains. Ten others had damage done to the right side of their brains but no loss in ability to understand or speak. The women on the videotapes spoke of feeling happy and relaxed as they watched pleasant nature scenes, which were not visible to the subjects watching their faces.