Biological motion stimuli, depicted as orthographically projected point-light displays, do not contain any information about their orientation in depth. For instance, the fronto-parallel projection of a point-light walker facing the viewer is the same as the projection of a receding walker. Even though inherently ambiguous, observers tend to interpret such walkers as facing the viewer. While some have suggested that this facing-the-viewer (FTV) bias exists for sociobiological reasons, there is currently a lack of evidence to support this claim.
The goal of this study was to correlate individual differences in psychological characteristics (i.e., anxiety, depression, and personality traits) with the FTV bias. We hypothesized that the FTV bias would be positively correlated with measures of anxiety, as we rationalized that more anxious individuals would be more worried about misinterpreting an approaching person as a receding one. In addition to measuring the socially loaded FTV bias, we also assessed the degree of a socially neutral bias: The tendency to perceive the walker from above rather than from below (i.e., the viewing-from-above, or VFA, bias). None of the characteristics correlated with the FTV bias, but we found that anxiety (both as a current mood state and as a personality trait) was negatively correlated with the VFA bias. More anxious individuals were less likely to perceive walker stimuli as if viewing them from above. This result is discussed in the context of other studies which seem to indicate that anxiety impacts the use of statistical priors to disambiguate visual stimuli.
Meeting abstract presented at VSS 2012