Narrator: This is Science Today. Neuropsychologists believe that people with a neurodegenerative disease known as frontotemporal dementia, or FTD, are unable to detect sarcasm and lies. Researchers at the University of California, San Francisco, tested patients' ability to detect insincerity in speech and used magnetic resonance imaging to identify deteriorations in different parts of the brain.
Rankin: What we found out about this deception finding was that patients who had difficulty picking up on the fact that one person's lying to another had damage to the left sort of lateral-outside part of the orbitofrontal cortex.
Narrator: Study leader Katherine Rankin explains that FTD attacks this part of the brain early in the disease, causing patients to lose the ability to discern fact from fiction.
Rankin: The research is really about coming up with a very good test to early identify these FTD patients. So, a physician or maybe a primary care doctor in Kansas can apply some of these tests, give a half hour, an hour worth of tests and they can come up with a diagnosis that actually is accurate.
Narrator: For Science Today, I'm Larissa Branin.