Asymmetrical interference between item and order information in short-term memory

Abstract

To recall a list of items just after the end of the presentation, participants must encode both the items and the order in which they were presented. Despite a long history of studying item and order information, little is known regarding the relation between them. Here, we examined this issue with a novel task in which participants saw two 4- or 6-item lists on each trial, along with specific instructions for each list to be encoded for subsequent item information retrieval or order reconstruction. In Experiments 1, 2, and 5, words were used for both item and order lists, whereas in Experiments 3 and 4, words were used for one list and characters for the other. An item recognition task was used in Experiments 1-4, and item reconstruction from a fragment was used in Experiment 5. The general finding was that order retention was hindered when both lists required order reconstruction compared to when one list required item information only. In certain circumstances, retention of items in the first list was impaired when the second list also required item retention. We address the pattern of results with a new theoretical account in which overwriting occurs for similar materials and in which there is a capacity limit specific to order information. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Figure 1.

Proportion of correct response for Experiment 1 as a function of encoding condition (different, same), and tested list (list 1, list 2) for each memory test (order test, item test). Error bars show standard error of the mean.

Figure 2.

Proportion of correct response for Experiment 2 as a function of encoding condition (different, same), and tested list (list 1, list 2) for each memory test (order test, item test). Error bars show standard error of the mean.

Figure 3.

Proportion of correct response for Experiment 3 as a function of encoding condition (different, same), and tested list (list 1, list 2) for each memory test (order test, item test). Error bars show standard error of the mean.

Figure 4.

Proportion of correct response for Experiment 4 as a function of encoding condition (different, same), and tested list (list 1, list 2) for each memory test (order test, item test). Error bars show standard error of the mean.

Figure 5.

Proportion of correct response for Experiment 5 as a function of encoding condition (different, same), and tested list (list 1, list 2) for each memory test (order test, item test). Error bars show standard error of the mean. The solid line in the order test panel represents mean performance of the order task in the single list condition, while the dashed line in the item test panel represents mean performance of the item task in the single list condition.