Figure 1.

Single-trial structure of the different block types used in Experiments 1 and 2. In TGBs (left), stimuli were classified according to two different categorization rules (shape or color) that could repeat or alternate across trials. In the shape task, participants were instructed to respond with the left hand to a square and with the right hand to a circle. In the color task, participants were instructed to respond with the left hand to a blue stimulus and with the right hand to an orange stimulus. Half of the blocks were performed with the left and right middle fingers (A) and the other half with the left and right ring fingers (B). In RSBs (right), stimuli were classified according to only one of the categorization rules, but the response set used for task implementation (middle fingers or ring fingers) could repeat or alternate across trials. Half of the blocks required color categorization (C), and the other half classification of shape (D). Note: Red circles indicate the correct responses in each of the examples.