The effect of suprathreshold contrast on stimulus centroid and its implications for the perceived location of objects.

Using an alignment task, we investigate the role of suprathreshold contrast upon the perceived location of asymmetric Gaussian-windowed stimuli. A model which extracts the centroid of the stimulus envelope between limits defined by contrast threshold accounts well for the observed variation in perceived position. This finding helps to explain previous discrepancies in the literature regarding the validity of stimulus centroid as a determinant of visual location.