Figure 3.

Psychometric function transition thresholds for each subject. Thresholds for gap/overlap responses for the SP and PO tasks. Seven subjects' thresholds shifted to an earlier time in the PO task, and two subjects' thresholds shifted to a later time. Only one subject showed a negative threshold, i.e., S8, in both the SP and PO tasks, responded overlap even though there was a gap. The variability across subjects suggests the transition threshold is not random, but depends upon the subject and the task. The wide range of TA thresholds makes it unlikely that a low-level, early visual process can account for the shift of the thresholds. (Dots and error bars are mean ± 1 SEM from the last 1000 MCMC chains.)