Feeling of embarrassment linked to brain

In people who show low levels of embarrassment -- including those with dementia -- this brain region is smaller than normal, found the researchers.

"This region is actually essential for this reaction. When you lose this region, you lose this embarrassment response," lead researcher Virginia Sturm told LiveScience.

According to the researchers, the embarrassment centre is focused in an area called the pregenual anterior cingulate cortex; this tissue resides deep inside your brain, to the front and the right.

This region is integral in regulating many automatic bodily functions, such as sweating, heartbeat and breathing, but also participates in many thinking-related functions, including emotions, reward-searching behaviours (like those implicated in addiction) and decision-making.

"It has projections to higher centres and also has projections down to lower centres," Sturm said. "It has a dual role in both visceral and also motor reactions." Size and shape of brain regions near this one have been associated with differences in personality. It's believed that the bigger a particular brain region, the more powerful the functions associated with it would be.

For instance, extroverts have larger reward-processing centres, while anxious and self-conscious people have larger error-detection centres. Very giving people have larger areas associated with understanding other's beliefs, studies have shown.

Those with dementia tend to have lowered levels of embarrassment, even when watching themselves singing miserably. Many things that those with dementia do, such as giving strangers massages or eating off of others' plates, don't seem to embarrass them.

When Sturm scanned their brains, she noticed that the less self-conscious and embarrassed the participants were, the smaller this embarrassment region in their cingulate cortex was.

Scanning this region of the brain could help diagnose these conditions earlier, since behavioural and social changes tend to happen before other symptoms that manifest themselves more obviously.

"A better understanding of the emotional changes that occurring in these diseases could be helpful early in the course of disease when the diagnosis might not be so obvious," said Sturm who presented the findings at the American Academy of Neurology meeting in Hawaii.

"There could be a host of emotional or social changes that go along with the diseases," she added.