STEVE INSKEEP, HOST:
If you ever tell a lie, it would be normal for your conscience to bother you. But here's a question. If you tell many lies, does that voice inside go quiet? Neuroscientists recently explored this idea. And our colleague Rachel Martin sat down to talk about it with NPR's social science correspondent Shankar Vedantam.
RACHEL MARTIN, HOST:
SHANKAR VEDANTAM, BYLINE: Hey, Rachel.
MARTIN: So we're talking about neuroscientists. They were studying the brain, as they are known to do.