Lili Sahakyan

Memory, monitoring, and control in the attainment of memory accuracy

Abstract Three experiments assessed people’s ability to strategically regulate memory accuracy in free report. Older adults were substantially less accurate than young adults in free report cued recall. Both older and younger adults made gains in memory accuracy from forced report to free report, but older adults did so at the expense of greater losses in quantity correct. This pattern of gains in accuracy at the cost of losses in quantity was mediated by the level of memory monitoring, and older adults showed less correspondence between their confidence judgments and the accuracy of their responses. When young adults encoded items with full vs. divided attention, the resulting differences in retention set off a cascade of effects including poorer memory monitoring and, ultimately, lower accuracy in free report. We suggest that older adults’ problems with memory monitoring and memory accuracy stem from impairments in their ability to recollect details of events.

Directed forgetting in incidental learning and recognition testing: Support for a two-factor account

Instructing people to forget a list of items often leads to better recall of subsequently studied lists (known as the benefits of directed forgetting). The authors have proposed that changes in study strategy are a central cause of the benefits (L. Sahakyan & P. F. Delaney, 2003). The authors address 2 results from the literature that are inconsistent with their strategy-based explanation: (a) the presence of benefits under incidental learning conditions and (b) the absence of benefits in recognition testing. Experiment 1 showed that incidental learning attenuated the benefits compared with intentional learning, as expected if a change of study strategy causes the benefits. Experiment 2 demonstrated benefits using recognition testing, albeit only when longer lists were used. Memory for source in directed forgetting was also explored using multinomial modeling. Results are discussed in terms of a 2-factor account of directed forgetting.

Remembering to Forget The Amnesic Effect of Daydreaming

Daydreaming mentally transports people to another place or time. Many daydreams are similar in content to the thoughts that people generate when they intentionally try to forget. Thus, thoughts like those generated during daydreaming can cause forgetting of previously encoded events. We conducted two experiments to test the hypothesis that daydreams that are more different from the current moment (e.g., in distance, time, or circumstance) will result in more forgetting than daydreams that are less different from the current moment, because they result in a greater contextual shift. Daydreaming was simulated in the laboratory via instructions to engage in a diversionary thought. Participants learned a list of words, were asked to think about autobiographical memories, and then learned a second list of words. They tended to forget more words from the first list when they thought about their parents’ home than when they thought about their current home (Experiment 1). They also tended to forget more when they thought about an international vacation than when they thought about a domestic vacation (Experiment 2). These results support a context-change account of the amnesic effects of daydreaming.

Unexpected Costs of High Working Memory Capacity Following Directed Forgetting and Contextual Change Manipulations

Greater working memory capacity is usually associated with greater ability to maintain information in the face of interruptions. In two experiments, we found that some types of interruptions actually lead to greater forgetting among high-span people than among low-span people. Specifically, an instruction designed to change mental context resulted in significant forgetting for high-span people but minimal forgetting among the low-span people. Intentional forgetting instructions also resulted in greater forgetting among higher working memory capacity participants than among lower working memory capacity participants. A candidate explanation called the intensified context shift hypothesis is proposed which suggests that high-span people are more context dependent than low-span people.

Oh, honey, I already forgot that: strategic control of directed forgetting in older and younger adults.

Two experiments investigated list-method directed forgetting with older and younger adults. Using standard directed forgetting instructions, significant forgetting was obtained with younger but not older adults. However, in Experiment 1 older adults showed forgetting with an experimenter-provided strategy that induced a mental context change--specifically, engaging in diversionary thought. Experiment 2 showed that age-related differences in directed forgetting occurred because older adults were less likely than younger adults to initiate a strategy to attempt to forget. When the instructions were revised to downplay their concerns about memory, older adults engaged in effective forgetting strategies and showed significant directed forgetting comparable in magnitude to younger adults. The results highlight the importance of strategic processes in directed forgetting.

Destructive effects of “forget” instructions

In two experiments, participants were given three lists of words to study and were told to (1) remember all three lists, (2) forget the first list immediately after studying it but try to remember the other two lists, or (3) forget the middle list immediately after studying it but try to remember the first and the last lists. In Experiment 1, unrelated word lists were used, whereas Experiment 2 replicated Experiment 1 with categorical lists. The results from both experiments showed that forgetting the middle list leads also to recall decrement for the first list, which was not intended for forgetting. The results are discussed in terms of the contextual change hypothesis of directed forgetting.

Self-evaluation as a moderating factor of strategy change in directed forgetting benefits

In list method directed forgetting, instructing people to forget a studied word list usually results in better recall for a newly studied list. Sahakyan and Delaney (2003) have suggested that these benefits are due to a change in encoding strategy that occurs between the study of the first list and the study of the second list. To investigate what might mediate such strategy change decisions, in two experiments we induced bothforget and remember participants to evaluate their memory performance on the two lists. In Experiment 1, they were asked to explicitly recall the items from the first list before studying the second list. In Experiment 2, after the study of the first list, the participants provided a rapid aggregate judgment of learning. Evaluation eliminated the differences between the forget and remember groups for the second list in both experiments, because the remember group achieved recall levels comparable to those for the forget group. The role of performance evaluation in mediating directed forgetting benefits is discussed.

List-Method Directed Forgetting in Cognitive and Clinical Research: A Theoretical and Methodological Review

The primary purpose of this chapter is to provide an up-to-date review of the twenty-first century research and theory on list-method directed forgetting (DF) and related phenomena like the context-change effect. Many researchers have assumed that DF is diagnostic of inhibition, but we argue for an alternative, noninhibitory account and suggest reinterpretation of earlier findings. We first describe what DF is and the state of the art with regard to measuring the effect. Then, we review recent evidence that brings DF into the family of effects that can be explained by global memory models. The process-based theory we advocate is that the DF impairment arises from mental context change and that the DF benefits emerge mainly but perhaps not exclusively from changes in encoding strategy. We review evidence (some new to this paper) that strongly suggests that DF arises from the engagement of controlled forgetting strategies that are independent of whether people believed the forget cue or not. Then we describe the vast body of literature supporting that forgetting strategies result in contextual change effects, as well as point out some inconsistencies in the DF literature that need to be addressed in future research. Next, we provide evidence—again, some of it new to this chapter—that the reason people show better memory after a forget cue is that they change encoding strategies. In addition to reviewing the basic research with healthy population, we reinterpret the evidence from the literature on certain clinical populations, providing a critique of the work done to date and outlining ways of improving the methodology for the study of DF in special populations. We conclude with a critical discussion of alternative approaches to understanding DF.Abstract The primary purpose of this chapter is to provide an up-to-date review of the twenty-first century research and theory on list-method directed forgetting (DF) and related phenomena like the context-change effect. Many researchers have assumed that DF is diagnostic of inhibition, but we argue for an alternative, noninhibitory account and suggest reinterpretation of earlier findings. We first describe what DF is and the state of the art with regard to measuring the effect. Then, we review recent evidence that brings DF into the family of effects that can be explained by global memory models. The process-based theory we advocate is that the DF impairment arises from mental context change and that the DF benefits emerge mainly but perhaps not exclusively from changes in encoding strategy. We review evidence (some new to this paper) that strongly suggests that DF arises from the engagement of controlled forgetting strategies that are independent of whether people believed the forget cue or not. Then we describe the vast body of literature supporting that forgetting strategies result in contextual change effects, as well as point out some inconsistencies in the DF literature that need to be addressed in future research. Next, we provide evidence—again, some of it new to this chapter—that the reason people show better memory after a forget cue is that they change encoding strategies. In addition to reviewing the basic research with healthy population, we reinterpret the evidence from the literature on certain clinical populations, providing a critique of the work done to date and outlining ways of improving the methodology for the study of DF in special populations. We conclude with a critical discussion of alternative approaches to understanding DF.

The Influence of Directional Associations on Directed Forgetting and Interference

Two experiments examined how cross-list directional associations influenced list-method directed forgetting and the degree of interference observed on each list. Each List 1 item had a (a) bidirectionally related item on List 2 (chip <----> potato), (b) forward association with an item on List 2 (chip --> wood), (c) backward association from an item on List 2 (chip <-- chisel), or (d) no relationship with List 2 items. The results revealed that associative relationships that eliminated retroactive interference in the baseline condition also eliminated the directed forgetting costs. In contrast, associative relationships did not affect List 2 recall in the forget group, which remained unchanged across experimental conditions. However, certain conditions reduced proactive interference in the remember group, thereby eliminating the benefits of directed forgetting. The directed forgetting costs and benefits were observed independently of each other. The authors propose that these effects emerged from a combination of item and context strengthening induced by different associative directions.

Where is the forgetting with list-method directed forgetting in recognition?

Despite the fact that list-method directed forgetting instruction leads to decreases in memory performance on tests of free recall, there are to date no published reports of comparable effects in recognition testing. In the present article, we evaluated whether conditions that promote the importance of context in recognition, either via stimulus selection (Experiments 1 and 2) or by test choice (Experiment 3), elicit directed forgetting impairment. In all three experiments, we obtained reliable recognition deficits, suggesting that the typical conditions of recognition, rather than recognition itself, underlie the discrepancy between the tests of recognition and free recall in list-method directed forgetting.