Figure 5.

Mean correct responses as a function of display collapsed across observers in Experiment 3. Evidence consistent with unlimited capacity was obtained for surfaces that could not be discriminated on the basis of single pacmen inducers (a). Evidence of fixed capacity was obtained when either the top or bottom half of each surface from Figure 4 was removed and participants were forced to complete the task by using the relative angle position of two inducers (b). Based on the results of these control experiments, we concluded that observers in Experiments 1 and 2 used a surface representation to perform the task and not the position of either single inducers or the relative alignment of a couple inducers. Error bars are within-subject 95% confidence intervals (Cousineau, 2005; Morey, 2008).