Believing is seeing : the link between paranormal beliefs and perceiving signal in noise

Research suggests that at the core of paranormal belief formation is a tendency to attribute meaning to ambiguous stimuli. But it is unclear whether this tendency reflects a difference in perceptual sensitivity or a decision bias. Using a two-alternative forced choice task, we tested the relationship between paranormal belief and perceptual sensitivity. Participants were shown two stimuli presented in temporal succession. In one interval an ambiguous Mooney Face (i.e., signal) was presented, in the other interval a scrambled version of the image (i.e., noise) was presented. Participants chose in which of the two intervals the face appeared. Our results revealed that participants with stronger beliefs in paranormal phenomena were less sensitive to discriminating signal from noise. This finding builds on previous research using "yes/no" tasks, but importantly disentangles perceptual sensitivity from response bias and suggests paranormal believers perceive things differently.