Brain memory finding may help schizophrenia research

A variation in a part of the brain may explain why some people have a better memory of reality than others and could advance understanding of brain disorders like schizophrenia, scientists said Tuesday.

In a study published in the Journal of Neuroscience, researchers from Cambridge University tested 53 volunteers and found differences in their ability to distinguish between real or imagined memories.

The scientists then found a direct link between these results and the size of a specific area of the brain called the paracingulate sulcus, or PCS.

The PCS is one of the last regions of the brain to develop before birth, and the study found that people with a larger PCS were better at discerning real experiences from imagined ones.

"The memory differences we observed were quite striking. It is exciting to think that these individual differences in ability might have a basis in a simple brain folding variation," said Cambridge's Jon Simons, who led the research.

The findings may also help scientists understand more about schizophrenia, he said, because an inability to recognize what is real and what isn't is a hallmark of the disease.

"Hallucinations are often reported whereby, for example, someone hears a voice when nobody's there. Difficulty distinguishing real from imagined information might be an explanation for such hallucinations," Simons said. "The person might imagine the voice but misattribute it as coming from the outside world."

Schizophrenia (in Greek, "split mind") is a severe mental illness characterized by a variety of symptoms including but not limited to a loss of contact with reality.

. bizarre behavior
. disorganized thinking
. disorganized speech
. decreased emotional expressiveness
. diminished or loss of contact with reality
. diminished to total social withdrawal

Schizophrenia afflicts approximately one percent of the world's population, making it the most common psychosis. Schizophrenia is characterized by positive and negative symptoms. Fundamental symptoms include thought disturbance, withdrawal, and difficulties managing effect. Secondary symptoms include perception disorders such as hallucinations and grandiosity. Symptoms may also be non-schizophrenic in nature, including anxiety, depression, and psychosomatic symptoms.

Schizophrenia is a severe mental disorder which affects 24 million people worldwide, according to World Health Organization data, yet relatively little is known of its causes.

"We've found evidence that suggests this particular (brain)region might be reduced in people with schizophrenia, and that this could be the beginning of an explanation for why these people experience hallucinations," Simons said in a telephone interview.