Figure 2.

A–C, Illustration of the features defining the FC (A), FS (B), and FS enhanced-difficulty (C) stimuli. Solid lines indicate pairings of crossmodal features in target bowls, and dashed lines indicate pairings of crossmodal features in distractor bowls. For the FC stimuli, feature binding was required for correct bowl selection, as each individual odor and texture were associated with both a target and a distractor bowl. For both types of FS stimuli, feature binding was not required, as rats could rely on a single feature (odor or texture) for correct bowl selection. However, for the FS enhanced-difficulty stimuli, rats had the additional requirement of learning when to rely on odor and when to rely on texture to determine the correct bowl choice as one odor (odor 7) and one texture (texture 8) were associated with both a target and a distractor bowl.