“…Maes, Damen, and Eling (2004), Maes, Vich, and Eling (2006) have replicated this finding. Moreover, Reed and Means (2004) found that participants, performing a category-learning task, responded slower on successive trials when the value of task-irrelevant stimulus dimensions changed, relative to when these values did not change across trials. Interestingly, this manipulation of task-irrelevant dimension values affected task performance without the participants having any explicit memory for these values.…”