VOA常速英语:Brain Researchers Uncover Secrets of Memory

HOUSTON, TEXAS — Much research on the human brain is focused on understanding how people form memories, store them and retrieve them. Now, a study by scientists at the University of California-Davis and the University of Texas Health Science Center in Houston is providing new insight into the process. Researchers at the two schools found that separate areas of the brain coordinate much like little radio stations - to form memories involving time and space.

In Memorial-Hermann hospital at the University of Texas Medical Center in Houston, Neurosurgeon Nitin Tandon visits 26-year-old epilepsy patient Tyler.

Dr. Tandon has placed platinum electrodes on the surface of Tyler's brain so that he can monitor electrical signals when Tyler is having a seizure.

"Before we can even understand how we would come up with prosthetic devices that we may be able to use to supplant certain brain functions that have been lost, we have to model those and understand those at a computational level," Tandon said.

Since such studies contribute to the understanding of epilepsy, Tyler is a willing participant.

"I think the more education there is about it, the better off the rest of the people will be," Tyler said.

Patients like Tyler have also contributed to a study of how the brain forms memories of events in terms of time and space.

“It has been a puzzle how the brain communicates both with the "where" and the "when" areas,” Tandon said.

Dr. Tandon had patients with implanted electrodes carry out learning tasks that involved both space and time to see how the brain handled the information.

"The way the brain does this, that it accomplishes communication with these two different areas at the same time, is by using two different frequencies coming from the same part of the brain, the hippocampus," he said.

The hippocampus is a structure on the lower side of the brain that regulates the formation of memories that are then stored in separate areas of the brain.

“It is very much like saying that you have a radio station that is sending out signals to two different groups of listeners at the same time and it does that by using two different frequencies,” Tandon said.

At the University of California, Davis, neuroscientist Arne Ekstrom analyzed data from the brain scans -- applying graph theory techniques used to study information flow.

He, Tandon and their colleagues hope to pursue this investigation in future studies.

Since memory loss is one of the problems associated with epilepsy, Dr. Tandon says this research holds promise for epileptics as well.

“We are setting ourselves up for being able to restore memory dysfunction much better than we have with these electrodes in patients with epilepsy and also, potentially, at some point, being able to restore normal network dynamics,” Tandon said.

Dr. Tandon hopes that one day such advances could help epileptic patients like Tyler lead more normal lives.