clipped from news.yahoo.com

Researchers at the University of New South Wales found that patients under the age of 65 suffering from frontotemporal dementia (FTD), the second most common form of dementia, cannot detect when someone is being sarcastic.

"This is significant because if care-givers are angry, sad or depressed, the patient won't pick this up. It is often very upsetting for family members," said John Hodges, the senior author

"(FTD) patients present changes in personality and behaviour. They find it difficult to interact with people, they don't pick up on social cues, they lack empathy, they make bad judgements,"

"People with FTD become very gullible and they often part with large amounts of money,"

"One of the things about FTD patients is that they don't detect humour -- they are very bad at double meaning and a lot of humour (other than sarcasm) is based on double meaning,"

The sarcasm test could replace some more expensive and less widely available tests for dementia, he said.