The number–letter, color–shape, and category-switch tasks assessed how efficiently participants could shift between two subtasks (respectively, classifying numbers vs. letters, colors vs. shapes, and size vs. animacy of words). Before each trial, a cue indicated which subtask to perform, with the cue sometimes being the same in two consecutive trials (repeat trials) and other times being different (switch trials). The dependent measures were switch costs, calculated as the RT difference between the switch and repeat trials.
