Fig. 1

The task was to indicate whether a change in any of the three polygons occurred between the first and second presentations. In all trials, the position of each polygon was different in the first and second presentations. There were two conditions, each presented in its own block of 32 trials. In the shape only (SO) condition, the polygons only varied in shape in both presentations (all were presented as black, on a gray background). In 50% of the trials, the shape of two polygons differed in the second presentation from the first. In the other 50% of the trials, the shapes of all three were identical in the first and second presentations. In the color-shape binding (CSB) condition, each polygon had a different color in the first presentation. In 50% of the trials, on the second presentation, two polygons swapped their colors. On the other 50% of the trials, the same color-shape combinations were presented in both presentations. In both conditions, the first presentation lasted for 2 s, was followed by a blank screen for 900 ms, and then the second set of polygons was presented until the participant responded