July 27, 2009

Famous Names Get Single Neurons Fired Up

MONDAY, July 27 (HealthDay News) -- As you read her name, your Oprah neuron will probably rev up.

An international team of researchers has found that single neurons in the brain's hippocampus activate when people recognize a photo or name, even if the image or name is distorted or presented in less than perfect fashion.

"Different pictures of Marilyn Monroe can evoke the same mental image, even if greatly modified as in [Andy] Warhol's famous portraits," lead researcher Rodrigo Quian Quiroga, head of bioengineering at the University of Leicester in England, said in a news release. "This process relates to one of the most fascinating questions in neuroscience: How do neurons in the brain manage to abstract and disregard irrelevant details to recognize highly variable pictures as the same person?"

While people process visual and auditory information through separate pathways, the information appears to converge in the hippocampus, a section of the brain associated with long-term memory and spatial navigation, according to the researchers' article appearing online July 23 in Current Biology and in print on Aug. 11.

In one experiment, Quiroga and his colleagues observed neuron activity in subjects while they looked at three images of the TV host Oprah Winfrey, saw her name appear on a computer screen or listened to an electronic voice saying "Oprah." A single neuron activated in the hippocampus during the Oprah experiment, while a different neuron fired when the subject was "Star Wars" hero Luke Skywalker or another famous person.

The more abstract the image of the familiar person or sound of his name, the greater the neuron activity along the pathway (visual or auditory) leading to the single neuron, the researchers found.

Single neurons even fired when the subjects heard or saw the name of Quian Quiroga, who was unknown to them a day or two before the experiment.

"This work gives us further understanding of how information is processed in the brain, by creating a high level of abstraction, which is important for perception and memory formation, given that we tend to remember abstract concepts and forget irrelevant details," Quian Quiroga said.

More information

The National Institute of Neurological Disorders and Stroke has more about neurons.

-- Kevin McKeever
SOURCE: University of Leicester, news release, July 2009
id=629242