 Campion et al. hypothesized that blindsight patients are conscious in that they are aware of visual signal where discriminability is low (cf. the twilight condition). Further, blindsight patients are more conservative in their response so will be apt to report the absence of a signal by saying that they do not see the relevant stimulus even though the signal is there, and they can detect it, as verified by their above chance visually guided behavior. This possibility was explicitly tested by Azzopardi and Cowey (1997) with the well-studied blindsight patient, GY. They compared blindsight performance with normal subjects at threshold vision using signal detection measures and found that with respect to motion stimuli, the difference between discrimination and detection used to argue for blindsight can be explained by changes in response criterion, as Campion et al. hypothesized. That is, GYs claim that he does not see the stimulus is due to a conservative criterion and not to a detection incapacity. Interestingly, for static stimuli, his response criterion did not change but his sensitivity did, as if he was tapping into two different visual processing mechanisms in each task (for an alternative explanation based on shifting response criterion, see Ko &amp; Lau 2012).