Figure 5.

Left: One of the stimulus patterns. In this one, the separation (“fuzzy edge”) is vertical, with the yellow on the right. In the experiment, this pattern will reappear four times, with the yellow on the right side (shown), the top side, the left side, and the bottom side. Correct responses are “left side” and “right side.” Thus, “top side” or “bottom side” indicate “sloppiness” in this example. Right: One of the catch trials. The stippled line divides the two panes, taking over the role of the hue boundary. Here, the correct response is “top side.” Anything else indicates “sloppiness.”