According to a study from researchers from the University of California, people with a type of neurodegenerative disease called frontotemporal dementia (FTD) can fail to notice sarcasm and lying.
“These are the patients who fall for all the online scams, and lose all their money, because they just don’t get the lie,” Katherine Rankin, who led the study, shared with NBC News in 2011. “They don’t understand sarcasm.”
“This fact can help them be diagnosed earlier,” she said ― which is a good thing, as the NHS advises that “an accurate and early diagnosis can have many benefits.”
The finding came after participants were asked to watch videos of interactions
The study, which involved 175 participants ― 103 of whom had some form of dementia and 72 of whom did not, as a control ― involved asking older people to assess videos of people having a conversation.
The people having these conversations were often being obviously sarcastic –this test was The Awareness of Social Inference Test, or TASIT.
After being given yes or no questions about what they saw, researchers measured participants’ responses against maps of their brain structure. They found that both Alzheimer’s and FTD patients struggled to pick up sarcasm, but FTD patients tended to struggle to discern liars more than those with Alzheimer’s did.
On top of that, “FTD patients don’t have that sense anymore that things that people do could turn out badly,” Rankin shared in 2022.
There are other signs of dementia, too
We’ve written before about how losing your sense of smell and taking smaller, more shuffling steps can both be signs of dementia.
Other early symptoms include:
- Struggling with timekeeping, or not being able to read an analogue clock
- Personality or mood changes, especially dramatic ones
- Struggling to find the right words or names
- Losing sight
- Sensory issues, like struggling with depth perceptions, loud noises, or changes to their sense of taste
- Hallucinations.
If you suspect dementia in yourself or a loved one, speak to a GP ASAP.