Brain Area Affects Sense of 'Self'

May 8, 2001 -- Scientists have pinpointed a key area of the brain that appears to govern personality, including one's religious, social and political beliefs, and even style of dress, according to a new study.

The section of the brain was isolated after studying a group of 72 people suffering from a rare degenerative disorder similar to Alzheimer's disease called frontotemporal dementia. Damage to the right frontal lobe of the brain by the disease creates radical changes in the identities of the patients, according to the study.

"We think of our 'self' — including our beliefs and values and even the way we dress — as something we determine, not just an anatomical process," Bruce Miller, a neurologist at the University of California, San Francisco and author of the study, said in a statement. "But this research shows that one area of the brain controls much of our sense of self, and damage to that area can dramatically change who we are."

Charming to Cheap?

Miller presents the findings today at the American Academy of Neurology's annual meeting in Philadelphia.

Miller began investigating the anatomy of the self after noticing that patients with frontotemporal dementia, which usually strikes people in their 50s, made dramatic changes in their life.

"One woman was a charming, dynamic real estate agent who went from wearing expensive designer apparel to choosing cheap clothing" Miller said. "Her preference for fine dining in French restaurants turned into a love of fast food."

Another patient, a 40-year-old man, sold his business and moved from job to job.

"At home he went from being tight-fisted and short-tempered to relaxed and easy-going," Miller said. His views on sex had been conservative, but they became tolerant and experimental, Miller said.

Of the 72 individuals studied, seven patients had a dramatic change of self. Of that group, six had the most serious abnormalities in the brain's right frontal lobe. The seventh patient had problems elsewhere in the brain, but the most severe were in the right frontal lobe.

"This suggests that normal functioning of the right frontal lobe is necessary for people to maintain their sense of self," Miller said. Biological disorder not only affects behavior, but can destroy patterns of self awareness, he said.

Miller told The Associated Press that scientists didn't yet understand why the right frontal lobe is so important to the sense of self.

"This is a kind of mysterious area in the brain," he said. "The question is why in this non-language area do we see a loss of self concepts. And the answer is: We don't know."