Semantic dementia is a newly discovered type of dementia and not yet fully understood. Its name originates from "semantics", the study of meaning. Semantic dementia causes degeneration only in the temporal lobe of the brain.
According to study researcher Jason Warren, someone with semantic dementia will lose their ability to understand language, and their eating habits undergo some unusual transformations. It seems that they in some way cease to understand their food.
Flavor information has become confused. For instance, they have trouble recognizing flavors that they used to know. And they are unsure whether different flavor combinations go together or not. With this jumbling of flavor information, for instance, peanut butter, horse radish and barbecue sauce might not raise an eyebrow.
"Also, while the current study did not directly examine the brain, it suggests areas affected by semantic dementia are involved how we think about flavors . Previous studies in healthy people have also shown the same brain areas damaged in semantic dementia are active when people make judgments about flavors, Warren said."
http://www.msnbc.msn.com/id/37155626/ns/health-alzheimers_disease