Possible underlying mechanisms for the biases observed in subjects’ localization responses.

Zero on the x-axis represents the center. In panels (B) and (D), the likelihood and posterior functions are overlapping and are shown in blue. In the visual domain, (A) a prior distribution located at the center of visual space could draw localization estimates towards the center, or (B) the likelihood distributions themselves could be biased, drawing sensory estimates towards a central location. In the auditory domain, (C) a prior bias for periphery could push perception of peripheral target estimates further away from the center of space, or (D) the likelihood distributions themselves maybe biased away from the center. Various combinations of these computational mechanisms were tested in the different proposed models (see Model Comparisons section).