The use of virtual reality to create a ‘laboratory’ is promising. As someone who has played computer games and has used the London underground (‘tube’) trains almost daily for 4 years, I was interested in the observations that those who used the tube regularly were less likely to have persecutory thinking in virtual reality, whereas an experience of playing computer games was a strong predictor of paranoid thinking. ^{Reference Freeman, Pugh, Antley, Slater, Bebbington, Gittins, Dunn, Kuipers, Fowler and Garety1}

I am not sure whether the observations can be justified by an assumption that the game-playing individuals were reacting because they automatically processed the computer characters as real. The use of a virtual reality environment may have introduced a bias not taken into account just by estimating the duration of game play.

Cognition and automatic thoughts are based on prior experiences. Has this study taken into account how prior gaming experience may affect one's perception to a virtual reality environment, as opposed to a generalised cognition easily translated to the real world? Is there a possibility that the participants automatically processed the environment as being hostile thus making the findings ‘a strong predictor of paranoid thinking’ only in a virtual world?

The data provided in the paper fail to show the nature of gaming experience these people have had. Is it possible that a person who plays non-violent strategy games, or gambles online, will have a different experience of virtual reality compared with someone who plays first-person shooters where one of the primary objectives of the game would be to survive, keep safe distance and, of course, to ‘kill’ other players when they are in range? Also, would the findings be different if some of these people who played computer games spent their time in virtual reality social networking worlds such as ‘Second Life’?

If an experience of travelling on the tube regularly shows less likelihood of feeling persecuted in a virtual train ride, can it be said that a prior experience of a threatening virtual reality environment make those who play games more likely to feel persecuted in the chosen medium than they would otherwise be in the real life?