It is the first time a paralysis patient has succeeded in meeting a person and having a conversation in an Internet virtual world, they added.

Researchers are now studying a system that would let patients create text messages by mentally selecting certain letters, said Junichi Ushiba, associate professor at the biosciences and informatics department of Keio Universty's Faculty of Science and Technology.

"In the near future, they would be able to stroll through Second Life shopping malls with their brain waves... and click to make a purchase," Ushiba said.

Second Life is an increasingly popular virtual world in which people -- and animals -- are represented by animated avatars and do everything from social activities to shopping.

Ushiba says Second Life could motivate patients with severe paralysis, who are often too depressed to undergo rehabilitation.