Figure 2.

Task and control conditions. Shown are sample trials for each control condition (each row illustrates one of 3 conditions). In the spectral control condition (1st row) subjects focus only on the spectral feature (in purple). In the temporal control condition (2nd row) subjects only focus on the temporal feature (in yellow). In the object control condition (3rd row), they encode the object as a whole (both features in combination). Both single feature control conditions differ from the single feature experimental conditions in the following way: the irrelevant feature (*) is held constant at the middle value of the corresponding stimulus range. The object control condition differs from the experimental object condition in the way that on change trials, the item presented at recall (probe) differs from the target (here: 2nd item in the sequence presented at encoding) by 1 feature, instead of 2 features.