Figure 1.

Screen events on a sample trial of phase 1 (learning). (A) At the start of the trial, 2 objects appear, differing in color or shape, but not both. The printed instruction is, “Which object is the smiley face under? Use `Left' or `Right' key to choose.” (B) The participant chooses 1 object, and that object rises onscreen; if the choice was correct, a smiley face appears below it. C) If incorrect, no smiley face appears. Figure adapted from Myers, Kluger et al, 2002.