People with Alzheimer's disease or early thinking and memory problems tend to
mirror the emotions of those around them, researchers find.
This transfer of emotions, known as emotional contagion, appears heightened
in people with Alzheimer's and related mental decline, according to the
University of California, San Francisco (UCSF) team. And it can be important in
the management of these patients, they added.
"Calm begets calm," said Dr Sam Gandy, associate director of the Mount Sinai
Alzheimer's Disease Research Center in New York City, who was not involved in
Emotional contagion is a rudimentary form of empathy, enabling people to
share and experience other people's emotions, said lead researcher Virginia
Sturm, an assistant professor in the UCSF department of neurology.
"It's a way by which emotions travel across people quickly and even without
awareness," explained Sturm. This process can shape behaviours and cause changes
in the brain, she added.
Strongest in early stages
In the early stages of Alzheimer's disease and in people with mild thinking
and memory problems, emotional contagion increases, the researchers found. It is
even more apparent in people with dementia, they noted.
"In Alzheimer's disease and other dementia we think some people may have an
increased sensitivity to other people's emotions," Sturm said.
"As their memory and thinking abilities decline, it seems this is accompanied
by the enhancement of other emotional processes," she said.
This means that if caregivers are anxious or angry, their patients will pick
up and copy these emotions.
On the other hand, if the caregiver is calm and happy, patients will emulate
these positive emotions, Sturm said.
Calm and happy
"This is a way Alzheimer's patients connect with others, even though they
don't have an understanding of the social situation," she said. "In order to
manage patients, it might be that the caregivers being calm and happy would go a
long way in keeping their patient calm and happy."
Alzheimer's disease is an age-related brain disorder that begins slowly and
gradually robs people of their ability to lead their everyday lives. In the
United States, one-third of the nation's seniors die with Alzheimer's or another
type of dementia, according to the Alzheimer's Association.
The study involved 237 adults. Sixty-two patients had mild memory and
thinking problems and 64 had Alzheimer's disease. The others were mentally
Participants took tests to identify depression and other mental health
problems and also underwent MRI scans to identify changes in the brain related
to emotional contagion.
The researchers found higher emotional contagion in those with mild mental
impairment and Alzheimer's disease, compared with those who did not have these
This growth of emotional contagion paralleled the increase in damage to the
right temporal lobe of the brain, reflecting biological changes in the neural
system, the study found.
"The right temporal lobe is important for different aspects of emotion and
social behaviour," Sturm said.
Depression was also greater among those with mild mental impairment and
Alzheimer's disease, the study found.
From a neurologist's perspective, "it is extraordinary that something so
complex as emotional perception can be controlled by such a localised part of
the brain," Gandy said.
"Also, classically it has been the frontal lobe damage that leads to
emotional disturbance," Gandy added. "Now we know the temporal lobes can play
For more information on Alzheimer's disease, visit the Alzheimer's Association.