PHILADELPHIA, PA - Researchers may have identified the area of the brain that controls our sense of self, according to a study presented during the American Academy of Neurology's 53rd Annual Meeting in Philadelphia, PA, May 5-11, 2001.
"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," said study author and neurologist Bruce L. Miller, MD, of the University of California, San Francisco. "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."
Miller started investigating the anatomy of the self after noticing that several of his patients with frontotemporal dementia underwent dramatic changes, from changing their political and religious beliefs to changing the clothes they wore and the food they ate.
"One woman was a charming, dynamic real estate agent who went from wearing expensive designer apparel to choosing cheap clothing and gaudy beads and asking strangers the cost of their clothing," Miller said. "Her preference for fine dining in French restaurants turned into a love of fast food."
In another case, a 40-year-old man sold his business and tried several jobs, but was always fired for irresponsible behavior. "He had been a critical, self-reliant person who recognized his own mistakes, but now he blamed his employers for his poor work record," Miller said. "At home he went from being tight-fisted and short-tempered to relaxed and easy-going. His views about sex, which had been puritanical, were now tolerant and even experimental -- he even urged his children to share his new, uninhibited philosophy."
"We wanted to figure out how this disease could cause such dramatic changes," Miller said.
For the study, researchers examined 72 people with frontotemporal dementia, a rare form of dementia that is often genetic and usually develops in people in their 50s. The patients were evaluated to identify those with a change in their "self," which was defined as changes in their political, social or religious values or style of dress. MRI and single photon emission computerized tomography (SPECT) images were used to determine which areas of the brain had the most severe degeneration from the disease.
Seven patients had a dramatic change of self. Of those, six had the most severe abnormalities in the brain's right frontal lobe. In the seventh patient, the right temporal lobe was the most affected. Of the 65 patients whose sense of self did not change dramatically, only one had the most severe damage in the right frontal lobe, Miller said.
"This suggests that normal functioning of the right frontal lobe is necessary for people to maintain their sense of self," Miller said. "It shows that a biological disorder can not only have profound effects on behavior, but it can even break down well-established patterns of awareness and self-reflection."
The patients with the loss of self had relatively normal memory and language functioning, which is impaired in some frontotemporal dementia patients, according to Miller.
A neurologist is a medical doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system.
The American Academy of Neurology, an association of more than 17,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research.
For more information about the American Academy of Neurology, visit its web site at www.aan.com
EDITOR'S NOTE: Dr. Miller will present the research at the American Academy of Neurology's 53rd Annual Meeting in Philadelphia, PA, during a platform presentation on Tuesday, May 8, 2001, at 3:45 pm in the Lecture Hall at the Pennsylvania Convention Center.
For more information contact:
Kathy Stone 651-695-2763
May 5-11, 215-418-2420