Figure 2.

A, An example trial from experiment 1. Observers viewed one, two, or six colored shapes in a sample display, and after a brief delay, judged whether the probe color at the center of the test display was present in the sample display. The encoding of object colors, but not their shapes, was task relevant. B, Left, Behavioral performance as indicated by Cowan's K measures (Cowan, 2001). Color encoding increased with increasing display set sizes and observers were able to retain maximally about three colors in VSTM. Right, fMRI peak responses from the superior IPS and the LOC ROIs. The superior IPS response was low for set size 1, medium for set size 2, and high for set size 6 displays. The LOC responses for set size 1 and 6 displays did not differ from each other, and both were lower than that for set size 2 displays. Errors shown are within-subject SEs.