Virtual Reality systems have been proved to be a valuable tool in the exposure treatment of different anxiety disorders. Virtual Spectators is an application created to be used by therapists in the treatment of social anxiety. The application allows the therapist to manipulate the difficulty of the task during the therapy session. The aim of the present study was to test the emotional impact of the application in non-clinical participants with different levels of social anxiety, by measuring Heart-Rate, Skin Conductance Responses and the Startle Reflex. Participants had to read two different texts (one easier and another more difficult) in front of a panel with three animated virtual judges, while their physiological responses were monitored continuously. From an initial pool of 95 participants, 32 (10 males) were selected to participate in the experiment according to their anxiety level (high or low). The results showed a general increase in heart-rate and skin conductance levels while they were reading the first text. A general differentiation between the groups was also observed in the heart-rate data, with participants in the high-anxiety group showing higher rates than in low-anxiety participants. Interestingly, the participants rated the exposure situation as more realistic while they were reading the more difficult text. In general, it can be concluded that the application Virtual Spectators seems to be a useful instrument to induce anxiety responses in exposure situations in the treatment of social anxiety.