Oliver Kliegl

List-method directed forgetting: The forget cue improves both encoding and retrieval of postcue information

In list-method directed forgetting, people are cued to forget a previously studied item list and to learn a new list instead. Such cuing typically leads to forgetting of the first list and to memory enhancement of the second, referred to as list 1 forgetting and list 2 enhancement. In the present study, two experiments are reported that examined influences of items’ serial learning position in a list and the two lists’ output order on list-method directed forgetting. The results show that list output order influences list 2 enhancement but not list 1 forgetting. The enhancement was higher when list 2 was recalled first than when list 1 was recalled first and, in both cases, was higher for early list 2 items than for middle and late list 2 items. In contrast, the forgetting was equally present for all list 1 items and did not depend on the two lists’ output order. The findings suggest that two separate factors can contribute to list 2 enhancement: one (encoding) factor that is restricted to early list 2 items and does not depend on list output order, and another (retrieval) factor that pertains to all list 2 items and varies with the two lists’ output order. A new two-mechanism account of directed forgetting is suggested that reconciles previous (encoding or retrieval) views on list 2 enhancement.

List-method directed forgetting can be selective: Evidence from the 3-list and the 2-list tasks

When people are cued to forget previously studied irrelevant information and study new information instead, such cuing typically leads to forgetting of the precue information. But what do people forget if, before the forget cue is provided, both irrelevant and relevant information have been encoded? Using relatively short item lists, we examined in a series of three experiments whether participants are able to selectively forget the irrelevant precue information, when relevant and irrelevant precue items were presented subsequently in two separate lists (3-list task) and when the two types of items were presented alternatingly within a single list (2-list task). Selective forgetting of the irrelevant precue items arose in the 3-list task, independent of modality of item presentation and level of discriminability of the precue lists, and it arose in the 2-list task. The findings suggest that, at least with relatively short precue lists, participants may well be able to selectively forget irrelevant precue information when cued to do so. Implications of the results for theoretical accounts of list-method directed forgetting are discussed.

Retrieval-induced remembering and forgetting

Selectively retrieving a subset of previously studied information enhances memory of the retrieved information but can cause forgetting of nonretrieved information. This chapter reviews the literature on such retrieval-induced forgetting (RIF), asking whether the forgetting depends on testing format, is retrieval specific and interference dependent, is modulated by retention interval after selective retrieval, and varies between individuals. The most prominent theoretical accounts of RIF are introduced and evaluated against the empirical findings. Also some more recent studies are reviewed, which indicate that, under certain conditions, selective retrieval can also improve memory of the nonretrieved information.

Selective directed forgetting in children

When, after study of an item list, adults are cued to forget some of the list items and encode new information instead, such cuing often induces selective forgetting of the to-be-forgotten material without impairing recall of the other items. This study examined developmental trends in such selective directed forgetting by having second graders, sixth graders, and young adults study three successive lists of items and, after study of List 2, cuing them either to remember both List 1 and List 2 or to forget List 2 but remember List 1. Consistent with prior work, second graders exhibited no forgetting at all in response to the forget cue, whereas young adults selectively forgot List 2. Sixth graders showed still another pattern with forgetting of both List 1 and List 2, suggesting that the ability to selectively forget is still absent at this age level. Directed forgetting has often been attributed to the action of inhibitory control processes. On the basis of this view, the current finding that children during middle childhood do not yet show selective forgetting indicates that the control processes underlying selective directed forgetting mature into adolescence and early adulthood.

A (Preliminary) Recipe for Obtaining a Testing Effect in Preschool Children: Two Critical Ingredients

The testing effect refers to the finding that retrieval of previously learned information improves retention of that information more than restudy practice does. While there is some evidence that the testing effect can already arise in preschool children when a particular experimental task is employed, it remains unclear whether, for this age group, the effect exists across a wider range of tasks. To examine the issue, the present experiments sought to determine the potential roles of retrieval-practice and final-test formats, and of immediate feedback during retrieval practice for the testing effect in preschoolers. Experiments 1 and 2 showed no testing effect in preschoolers when a free-recall task was applied during the final test, regardless of whether free recall (Experiment 1) or cued recall (Experiment 2) were conducted during retrieval practice. In contrast, if cued-recall tasks were used during both retrieval practice and the final test (Experiment 3), a reliable testing effect arose. Furthermore, the magnitude of the effect was dramatically enhanced when, in addition, immediate feedback was provided during retrieval practice (Experiment 4). The present findings suggest that cued-recall practice and test formats, as well as immediate feedback during practice, are crucial ingredients for obtaining the testing effect in preschoolers.