Aging and directed forgetting in episodic memory: A meta-analysis.

In this meta-analysis, we examined the effects of aging on directed forgetting. A cue to forget is more effective in younger (d = 1.17) than in older (d = 0.81) adults. Directed-forgetting effects were larger (a) with the item method rather than with the list method, (b) with longer presentation times, (c) with longer postcue rehearsal times, (d) with single words rather than with verbal action phrases as stimuli, (e) with shorter lists, and (f) when recall rather than recognition was tested. Age effects were reliably larger when the item method was used, suggesting that these effects are mainly due to encoding differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The crucial role of postcue encoding in directed forgetting and context-dependent forgetting.

People can intentionally forget previously studied material if, after study, a forget cue is provided and new material is learned. It has recently been suggested that such list-method directed forgetting arises because the forget cue induces a change in internal context and causes context-dependent forgetting of the studied material (L. Sahakyan & C. M. Kelley, 2002). The authors compared directed forgetting and context-dependent forgetting by examining whether, like a forget cue, a change in internal context needs subsequent learning of new material to be effective. Participants studied an item list and, after study, received a remember cue or a forget cue or their internal context was changed through an imagination task. In each condition, half the participants learned a second list, and the other half fulfilled an unrelated distractor task. Both the forget cue and the change in internal context induced forgetting of the first list only when learning of the second list was interpolated. These results suggest that postcue encoding of new material is crucial for both directed forgetting and (some forms of) context-dependent forgetting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amount of postcue encoding predicts amount of directed forgetting.

In list-method directed forgetting, participants are cued to intentionally forget a previously studied list (List 1) before encoding a subsequently presented list (List 2). Compared with remember-cued participants, forget-cued participants typically show impaired recall of List 1 and improved recall of List 2, referred to as List 1 forgetting and List 2 enhancement. In 3 experiments, we examined how amount of postcue encoding influences directed forgetting. Two results emerged dissociating List 1 forgetting from List 2 enhancement. First, an increase in amount of postcue encoding led to an increase in List 1 forgetting but did not affect List 2 enhancement. Second, the forget cue influenced all List 1 items but affected only early List 2 items. A 2-mechanism account of directed forgetting is suggested, according to which List 1 forgetting reflects reduced accessibility of List 1 items, and List 2 enhancement arises from a reset of encoding processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of retrieval practice in directed forgetting.

Three experiments tested the possibility that retrieval-induced forgetting is responsible for directed forgetting with the list method. In Experiments 1 and 2, additional List 2 retrieval practice was given to determine whether this would increase directed forgetting. In Experiment 1 all items came from a single category, and in Experiment 2 unrelated words were used. In Experiment 3 additional List 2 study accompanied List 2 retrieval practice. There was no evidence that List 2 retrieval practice, with or without additional List 2 study, affected the magnitude of directed forgetting. It was argued that retrieval-induced forgetting could not account for these results. Accounts with greater viability include retrieval strategy disruption and a modified version of the dissociation hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Directed forgetting of recently recalled autobiographical memories.

In 6 experiments, the authors investigated list-method directed forgetting of recently recalled autobiographical memories. Reliable directed forgetting effects were observed across all experiments. In 4 experiments, the authors examined the impact of memory valence on directed forgetting. The forget instruction impaired recall of negative, positive, and neutral memories equally, although overall, participants recalled fewer unemotional memories than emotional memories. The preexisting organization of memories enhanced the directed forgetting effect, and a release from forgetting occurred only when the forgotten memories were directly cued. The authors discuss the roles of emotion, retrieval dynamics, and organization in these effects and suggest that the directed forgetting of recently recalled autobiographical memories may reflect the inhibition of recently formed memories of remembering, that is, episodic inhibition. The authors consider the implications of these findings for the control of autobiographical remembering in everyday life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cardiorespiratory fitness, hippocampal volume, and frequency of forgetting in older adults.

Objective: The purpose of this study was to extend our earlier work to determine the extent to which cardiorespiratory fitness is associated with the frequency of memory problems via its effects on the hippocampus and spatial working memory. We hypothesized that age, sex, education, body composition, and physical activity were direct determinants of fitness, which, in turn, influenced frequency of forgetting indirectly through hippocampal volume and spatial working memory. Method: We conducted assessments of demographic characteristics, Body Mass Index (BMI), physical activity, cardiorespiratory fitness, hippocampal volume, spatial working memory, and frequency of forgetting in 158 older adults (M age = 66.49). Path analyses within a covariance modeling framework were used to examine relationships among these constructs. Results: Sex, age, BMI, and education were all significant determinants of cardiorespiratory fitness. The hypothesized path models for testing the effects of fitness on frequency of forgetting through hippocampal volume and accuracy and speed of spatial working memory all fit the data well. Conclusions: Our findings suggest that older adults with higher levels of fitness show greater preservation of hippocampal volume, which, in turn, is associated with more accurate and faster spatial memory and fewer episodes of forgetting. Given the proportion of older adults reporting memory problems, it is necessary to determine whether improvements in fitness brought about by physical activity interventions can result in subsequent attenuation of memory problems or potentially in improvements in memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Directed forgetting of emotional words.

Emotional material may induce processing limitations affecting memory performance. In the present study, the authors investigated how the emotional content of words influences the degree to which participants can be directed to forget them. In Experiment 1, the authors found that negative-valence words were recalled better when participants were told to forget them than when they were told to remember them. This effect was only obtained when a study-list of negative words was presented after the cue to remember or forget the first list. The effect was correlated with negative mood as assessed by the PANAS. Similar results were obtained in Experiment 2, in which the induction of negative arousal by a mild stressor abolished the directed forgetting of words when the following study list was comprised of negative words. These results support the idea that directed forgetting relies on cognitive control processes that may be disrupted by negative emotion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preferences for emotional information in older and younger adults: A meta-analysis of memory and attention tasks.

The authors conducted a meta-analysis to determine the magnitude of older and younger adults' preferences for emotional stimuli in studies of attention and memory. Analyses involved 1,085 older adults from 37 independent samples and 3,150 younger adults from 86 independent samples. Both age groups exhibited small to medium emotion salience effects (i.e., preference for emotionally valenced stimuli over neutral stimuli) as well as positivity preferences (i.e., preference for positively valenced stimuli over neutral stimuli) and negativity preferences (i.e., preference for negatively valenced stimuli to neutral stimuli). There were few age differences overall. Type of measurement appeared to influence the magnitude of effects; recognition studies indicated significant age effects, where older adults showed smaller effects for emotion salience and negativity preferences than younger adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monitoring one's own forgetting in younger and older adults.

The present study examined whether there are age-related differences in the ability to accurately monitor forgetting. Young and older adults studied a mixed list of categorized words, and later recalled items when cued with each category. They then estimated the number of additional items that they did not recall—a form of monitoring one's forgetting. Older adults exhibited impaired memory performance compared with young adults, but also accurately estimated they forgot more information than young adults. Both age groups were fairly accurate in predicting forgetting in terms of resolution, indicating that aging does not impair the ability to monitor forgetting. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Interference effects from divided attention during retrieval in younger and older adults.

The authors examined how retrieval, under divided attention (DA) conditions, is affected by the type of material in a concurrent task, and whether aging produces larger interference effects on memory. Young and old adults studied a list of unrelated words under full attention, and recalled them while performing either an animacy decision task to words or an odd-digit identification task to numbers. The animacy-distracting task interfered substantially with retrieval, and the size of the effect was not amplified in older compared with younger adults. DA using the odd-digit task did not produce as large an interference effect. These findings support the component-process model of memory, and pose problems for resource models of interference from DA at retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbosity and emotion recognition in older adults.

Previous research suggests that older adults are more verbose than young adults and that general inhibitory difficulties might play a role in such tendencies. In the present study of 60 young adults and 61 older adults, the authors examined whether verbosity might also be related to difficulty deciphering emotional expressions. Measures of verbosity included total talking time, percentage of time spent on-topic, and extremity of off-topic verbosity. Over all 3 measures, older men and women were significantly more verbose than young men and women. Older men's (but not older women's) verbosity was related to poorer emotion recognition, which fully mediated the age effect. The results are consistent with the idea that older men who talk more do so, in part, because they fail to decipher the emotional cues of a listener. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The structure of verbal abilities in young and older adults.

Four language sample measures as well as measures of vocabulary, verbal fluency, and memory span were obtained from a sample of young adults and a sample of older adults. Factor analysis was used to analyze the structure of the vocabulary, fluency, and span measures for each age group. Then an "extension" analysis was performed by using structural modeling techniques to determine how the language sample measures were related to the other measures. The measure of grammatical complexity was associated with measures of working memory including reading span and digit span. Two measures, sentence length in words and a measure of lexical diversity, were associated with the vocabulary measures. The fourth measure, propositional density, was associated with the fluency measures as a measure of processing efficiency. The structure of verbal abilities in young and older adults is somewhat different, suggesting age differences in processing efficiency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A contextual change account of the directed forgetting effect.

The authors propose that the costs and benefits of directed forgetting in the list method result from an internal context change that occurs between the presentations of 2 lists in response to a "forget" instruction. In Experiment 1 of this study, costs and benefits akin to those found in directed forgetting were obtained in the absence of a forget instruction by a direct manipulation of cognitive context change. Experiment 2 of this study replicated those findings using a different cognitive context manipulation and investigated the effects of context reinstatement at the time of recall. Context reinstatement reduced the memorial costs and benefits of context change in the condition where context had been manipulated and in the standard forget condition. The results are consistent with a context change account of directed forgetting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of goal-setting and feedback on memory performance and beliefs among older and younger adults.

This research examined the impact of goal-setting conditions on memory beliefs and performance among older and younger adults. After baseline recall and assessment of beliefs, participants were assigned to goal-setting, goals plus feedback, or control. Then, additional recall trials were followed by repeated memory beliefs assessments. For both younger and older adults, performance, motivation, and self-efficacy were affected positively by goal-setting. The impact of goals plus feedback was mixed and varied as a function of age and dependent measure. Success rates for reaching memory goals, which were low for the older adults, may have been a factor in these results. Adults' self-set recall goals were predicted initially by baseline performance and self-efficacy. On the final trial, goals were predicted by last trial performance, self-efficacy, and control beliefs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Directed forgetting meets the production effect: Distinctive processing is resistant to intentional forgetting.

The production effect refers to the fact that, relative to reading a word silently, reading a word aloud during study improves explicit memory. The authors tested the distinctiveness account of this effect using the item method directed forgetting procedure. If saying words aloud makes them more distinctive, then they should be more difficult to forget on cue than should words read silently. Participants studied a list of words by reading half aloud and half silently; half of the words in each of these subsets were followed by a Remember instruction and half were followed by a Forget instruction. There was a robust production effect for both Remember and Forget words on an explicit recognition test. Critically, however, a directed forgetting effect was observed only for words read silently; words read aloud at study were unaffected by memory instruction. An implicit speeded reading test showed equal priming for all studied items. This pattern supports a distinctiveness account of the production effect: Words processed distinctively during production are not influenced by subsequent rehearsal differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences in working memory capacity predict retrieval-induced forgetting.

Selectively retrieving a subset of previously studied information enhances memory for the retrieved information but causes forgetting of related, nonretrieved information. Such retrieval-induced forgetting (RIF) has often been attributed to inhibitory executive-control processes that supposedly suppress the nonretrieved items' memory representation. Here, we examined the role of working memory capacity (WMC) in young adults' RIF. WMC was assessed by means of the operation span task. Results revealed a positive relationship between WMC and RIF, with high-WMC individuals showing more RIF than low-WMC individuals. In contrast, individuals showed enhanced memory for retrieved information regardless of WMC. The results are consistent with previous individual-differences work that suggests a close link between WMC and inhibitory efficiency. In particular, the finding supports the inhibitory executive-control account of RIF. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Source memory in older adults: An encoding or retrieval problem?

Source memory has been found to be more affected by aging than item memory, possibly because of declining frontal function among older adults. In 4 experiments, the authors explored the role of the frontal lobes (FLs) in source memory, the extent to which they may be involved in the encoding and/or retrieval of source or context, and the conditions under which the source memory deficit in older people may be reduced or eliminated. Results indicated that only a subset of older adults show deficits in source memory, namely those with below average frontal function, and these deficits can be eliminated by requiring people at study to consider the relation between an item and its context. These results provide convincing evidence of the importance of frontal function during the encoding of source and suggest that older adults with reduced FL function fail to initiate the processes required to integrate contextual information with focal content during study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effective cue utilization reduces memory errors in older adults.

When compared with younger adults, older adults typically manifest poorer episodic memory. One hypothesis for the episodic memory deficit is that older adults may not encode contextual information as well as younger adults. Alternatively, older adults may use contextual information at retrieval less effectively when compared with younger adults. If older adults encode context less well than younger adults, then manipulations that affect context should have little effect on memory performance. To evaluate these 2 hypotheses, the authors used manipulations that promoted effective contextual cue utilization at retrieval. Retention interval and instructions at retrieval were manipulated within the imagination inflation paradigm. Results suggest that older adults encode contextual cues useful in improving memory performance but have difficulty accessing and using those cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cease remembering: Control processes in directed forgetting.

On the premise that committing a word to memory is a type of covert action capable of being stopped, this study merged an item-method directed forgetting paradigm with a stop signal paradigm. The primary dependent measure was immediate recall. Indicating that participants were able to countermand the default instruction to remember, there was an overall directed forgetting effect, the magnitude of which varied as a function of forget signal delay. The results suggest that the covert act of intentionally forgetting may engage cognitive control processes at encoding that are analogous to those required to prevent the execution of prepotent overt responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)