Order information in multiple-element comparison

Although it is possible to specify the elements of a list without regard to the order in which they appear, the same distinction may not be possible when the elements are retrieved from memory. To investigate this issue, 32 Ss performed a recognition task in which 2 strings of letters were presented sequentially in 2 experiments. Ss were instructed to respond "Same" if the 2nd string contained the same elements as the 1st, regardless of their position, and to respond "Different" otherwise. Despite the fact that order information was irrelevant in this task, RT for Same-item trials increased with the number of positions that the letters were displaced. Neither familiarity of the 1st string nor the delay between strings changed the size of this displacement effect. A model is proposed in which comparison time for a given letter pair increases with the position difference of the elements in their respective strings. (27 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).