FRIDAY, April 15 (HealthDay News) -- People who no longer recognize sarcasm or lies may be showing early signs of dementia, researchers from the University of California, San Francisco report.
The findings may help doctors diagnose which type of dementia a patient has and start to treat it early, the researchers said.
"The different dementia patients tended to have difficulty identifying the form of sarcasm we used for our study," said lead researcher Katherine P. Rankin, a neuropsychologist and associate professor of neurology. Whereas many dementia patients could easily recognize a lie, patients with frontotemporal dementia were unable to pick out either sarcasm or lies.
The results of the study were scheduled to be presented Thursday at the annual meeting of the American Academy of Neurology in Honolulu. Research presented at meetings is considered preliminary until it is published in a peer-reviewed journal.
For the study, Rankin's team asked 175 people, over half of whom had dementia, to watch videos of two people talking. At different spots in the tape one person would lie or say something sarcastic. Viewers were given verbal and nonverbal clues to help pinpoint the false or insincere statements, the researchers noted.
The study participants were then asked yes/no questions about what they had seen.
People suffering from corticobasal syndrome, progressive supranuclear palsy, amyotrophic lateral sclerosis, Alzheimer's disease and frontotemporal dementia were included in the study, as well as healthy individuals.
The researchers compared their scores with the results of brain scans that measured loss of volume related to dementia.
Healthy people easily picked out the lies and sarcasm, but those with frontotemporal dementia found it hard to distinguish among lies, sarcasm and fact. Patients with other types of dementia such as Alzheimer's d
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