so some think , she said , cautiously , continuing as though quoting from a paragraph of her degree dissertation , in this world where the individual is increasingly isolated , to the extent that over a million japanese teenagers are unable to leave their bedrooms for fear of the reality outside , and prefer instead to bury themselves in a make-believe of computer games and virtual worlds ... hikikomori syndrome , interrupted martin , attempting to show that he was up to speed with the direction of the discourse .