UCSF scientists have determined which areas of the brain govern a person’s ability to detect sarcasm, lies.

Katherine Rankin, UC San Francisco

By asking a group of older adults to analyze videos of other people conversing — some talking truthfully, some insincerely — a group of scientists at UC San Francisco has determined which areas of the brain govern a person’s ability to detect sarcasm and lies.

Some of the adults in the group were healthy, but many of the test subjects had neurodegenerative diseases that cause certain parts of the brain to deteriorate. The UCSF team mapped their brains using magnetic resonance imaging, MRI, which showed associations between the deteriorations of particular parts of the brain and the inability to detect insincere speech.

“These patients cannot detect lies,” said UCSF neuropsychologist Katherine Rankin, Ph.D., a member of the UCSF Memory and Aging Center and the senior author of the study. “This fact can help them be diagnosed earlier.”

The finding was presented today (April 14) at the 63rd Annual Meeting of the American Academy of Neurology in Hawaii, by Rankin and her postdoctoral fellow Tal Shany-Ur, Ph.D. The title of their presentation was, “Divergent Neuroanatomic Correlates of Sarcasm and Lie Comprehension in Neurodegenerative Disease.”

In a presentation today at the 63rd Annual Meeting of the American Academy of Neurology in Hawaii, Rankin and her postdoctoral fellow Tal Shany-Ur, PhD, will show the data, which suggests that it may be possible to spot people with particular neurodegenerative diseases early just by looking for the telltale sign of their inability to detect lies.

“We have to find these people early,” said Rankin. In general scientists believe that catching people early in the disease will provide the best opportunity for intervention when drugs become available.

The study is part of a larger body of work at UCSF’s Memory and Aging Center examining emotion and social behavior in neurodegenerative diseases as tools for better predicting, preventing and diagnosing these conditions.

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