Researchers reveal a marker and new testing tool of frontotemporal dementia that may help distinguish this condition from Alzheimer's disease.
Frontotemporal dementia (FTD) is a less common form of dementia than Alzheimer's. Sometimes called Pick's disease or frontal lobe dementia, this condition occurs when brain cells in the frontal or temporal lobes of the brain, or both, become damaged.
The frontal lobes of a person's brain are responsible for problem-solving, planning, emotional control, and behavior.
FTD may also affect the temporal lobes, which can be found on each side of the brain and deal with speech, the meaning of words, and recognition of faces or objects.
In addition to difficulties with language, FTD also causes changes in personality and behavior.
For instance, people with FTD may experience mood changes that do not normally characterize them. They may act more impulsively, lose their social inhibitions, feel apathetic, or lose interest in the emotions of other people or in socializing.
Although some of these symptoms are similar to other, more common forms of dementia, such as Alzheimer's disease, FTD is different from Alzheimer's.
In an attempt to distinguish FTD from Alzheimer's disease, researchers from the Brain and Spine Institute and the Pitié-Salpêtrière Hospital (both in Paris, France), set out to examine how FTD affects the "moral emotions" of those living with the condition.
Marc Teichmann is the first author of the paper, which appears in the Journal of Alzheimer's Disease.
"Moral emotions" describe "affective experiences promoting cooperation and group cohesion," explain Teichmann and colleagues. Such emotions include admiration, shame, or pity.
Studying 'moral emotions' in dementia
Teichmann explains the motivation for the current study, saying, "We have known for a long time that [FTD] patients demonstrate impairment of emotion recognition and theory of mind, i.e., the ability to figure out the mental states of others: what they think, what they feel, what they like..."
"But does this emotional blunting also affect a specific kind of emotions called moral emotions, which are crucial for human interactions?" asks the researcher. To find out, the team designed a test for assessing moral emotions.
The test had 42 hypothetical scenarios. The respondent in the test has to choose one of the four possible answers, each of which concerns the feeling that the scenario might elicit.
To distinguish between "regular" emotions and "moral" emotions, the researchers also asked the participants to respond to another 18 non-moral scenarios that would elicit similar — but non-moral — emotions.
For example, a particular situation can elicit admiration of the moral sort, say, for a person's generosity, but another, non-moral situation can elicit admiration for a beautiful painting.
Teichmann and colleagues administered the test to 22 people with FTD, 15 people with Alzheimer's, and 45 people who did not have either of the two conditions.
A new testing tool for FTD
The results of the research confirmed, as the researchers predicted, that FTD blunts emotions, in general.
However, it also revealed that FTD impairs moral emotions much more than non-moral ones in people with the condition. By contrast, people with Alzheimer's showed no impairment in this area and performed just as well in the test as people without either FTD or Alzheimer's.
The results of the study could lead to more precise diagnoses for FTD and may enable healthcare professionals to distinguish more accurately between FTD and Alzheimer's.
"Our findings confirm that emotions, in general, are impaired in FTD, and they reveal a particularly profound alteration of moral emotions," says Teichmann.
"Our novel test tool appears to provide an early, sensitive, and specific marker for FTD diagnosis while reliably distinguishing FTD from Alzheimer's disease patients. It could also be a marker for other diseases involving the breakdown of moral emotions as, for example, in the case of psychopathic individuals."