Rate of forgetting in amnesia: II. Recall and recognition of word lists at different levels of organization.

Amnesic rate of decline of free recall, cued recall, and recognition of word lists with different levels of organization was investigated in 2 experiments. In Experiment 1, it was found that amnesic free recall of semantically related word lists declined at an accelerated rate, whereas free recall of lists of unrelated words declined at a normal rate. Cued recall and recognition performance of both kinds of word lists appeared to decline at a normal rate. In Experiment 2, the results of the free-recall and recognition conditions were replicated using an improved experimental design. The observed amnesic forgetting pattern is interpreted as arising from an impairment in consolidation of long-term memory for complex associations between 2 or more items and their study context that is caused by extended hippocampal system lesions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibitory deficits in older adults: List-method directed forgetting revisited.

In list-method directed forgetting, participants are cued to intentionally forget a previously studied list while remembering a subsequently presented 2nd list. Results from prior research are inconclusive on whether older adults show deficits in this type of task. In 3 experiments, the authors reexamined the issue and compared younger and older adults' responsiveness to the forget cue. Across the experiments, the forget cue was varied within and between participants, the 2 lists were unrelated and related to each other, and recall of the lists was required simultaneously and successively. In none of the 3 experiments did any age-related difference in directed forgetting performance emerge. List-method directed forgetting is assumed to reflect retrieval inhibition. The present results thus challenge the proposal of a general inhibitory deficit in older adults' memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are independent probes truly independent?

The independent cue technique has been developed to test traditional interference theories against inhibition theories of forgetting. In the present study, the authors tested the critical criterion for the independence of independent cues: Studied cues not presented during test (and unrelated to test cues) should not contribute to the retrieval process. Participants first studied a subset of cues (e.g., rope) that were subsequently studied together with a target in a 2nd study phase (e.g., rope–sailing, sunflower–yellow). In the test phase, an extralist category cue (e.g., sports, color) was presented, and participants were instructed to recall an item from the study list that was a member of the category (e.g., sailing, yellow). The experiments showed that previous study of the paired-associate word (e.g., rope) enhanced category cued recall even though this word was not presented at test. This experimental demonstration of covert cuing has important implications for the effectiveness of the independent cue technique. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The list-strength effect in recall: Relative-strength competition and retrieval inhibition may both contribute to forgetting.

According to the principle of relative-strength competition, stronger items in memory block the retrieval of weaker items. This principle, integral to many theories of forgetting over the years, derives much of its support from the list-strength effect (LSE), in which strengthening some items in a study list makes it more difficult to recall other items. Work in the retrieval-induced forgetting literature has challenged the existence of relative-strength competition, 1st by offering many examples of a null LSE and 2nd by proposing that extant observations of the LSE can be explained by retrieval inhibition. In the present study, a series of experiments produced a robust LSE in cued recall under conditions meant to control the contribution of retrieval inhibition. Simulations of the SAM-REM model of recall (K. J. Malmberg & R. M. Shiffrin, 2005) showed that a model based on relative-strength competition can accommodate both the presence and absence of an LSE. The empirical results and model simulations together make a case for the role of strength-based competition in forgetting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired Implicit Memory for Gist Information in Amnesia.

In 2 experiments using a converging associates paradigm, the authors evaluated implicit memory for gist information in amnesic patients. In Experiment 1, participants saw multiple sets of associates, each converging on a nonpresented theme word, and were then tested using an implicit word stem completion test and an explicit cued recall test. Amnesic patients showed intact implicit and impaired explicit memory for studied words, but memory for nonpresented lures was impaired, regardless of retrieval instructions. To evaluate whether impaired implicit memory for lures was due to accelerated forgetting of gist information, short study lists were used in Experiment 2, each consisting of a single set of associates. Amnesics' implicit memory for lures was again impaired. These results point to an inability to encode robust gist representations as the cause of impaired gist memory in amnesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conjunction errors, recollection-based rejections, and forgetting in a continuous recognition task.

Six experiments investigated conjunction memory errors (e.g., falsely remembering blackbird after studying parent words blackmail and jailbird) in a continuous recognition procedure with a parent-conjunction lag manipulation. In 4 experiments (1A, 1B, 2A, and 2B) "recollect" judgments, which indexed recall of parent words, showed that participants can use recollection to prevent conjunction errors. "Recollect" judgments, as well as overt recall of parent words (in Experiments 2A and 2B), dropped sharply from a lag of 0 to 1 word, then stabilized from a lag of 1 to 20 words. Thus, the "recollect" responses and overt recall demonstrate a step function of forgetting over short intervals. These data generalized to cued recall in Experiments 3A and 3B with the first morpheme (e.g., black) as the cue, though recall conjunction errors occurred infrequently relative to recognition conjunction errors. Overall, the results support the idea that automatic and controlled processes contribute to memory performance. (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)     

When Remembering Causes Forgetting: Retrieval-Induced Forgetting as Recovery Failure.

Retrieval practice on a subset of previously learned material can cause forgetting of the unpracticed material and make it inaccessible to consciousness. Such inaccessibility may arise because the material is no longer sampled from the set of to-be-recalled items, or, though sampled, its representation is not complete enough to be recovered into consciousness. In 2 experiments, it was examined whether retrieval-induced forgetting reflects a sampling or recovery failure by studying the time course of cued recall in this type of situation. Although retrieval practice reduced recall totals of the unpracticed items, in both experiments, the forgetting was not accompanied by an effect on the items' response latencies. This pattern of results is consistent with the view that inhibited items are successfully sampled but, because of a reduction in their activation level, do not exceed the recovery threshold. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic, phonological, and hybrid veridical and false memories in healthy older adults and in individuals with dementia of the Alzheimer type.

Five groups of participants [young, healthy old, healthy old-old, very mild dementia of the Alzheimer type (DAT), and mild DAT] studied 12-item lists of words that converged on a critical nonpresented word (cold) semantically (chill, frost, warm, ice), phonologically (code, told, fold, old), or in a hybrid list of both (chill, told, warm, old). The results indicate that (a) veridical recall decreased with age and dementia; (b) recall of the nonpresented items increased with age and remained fairly stable across dementia; and (c) false recall varied by list type, with hybrid lists producing superadditive effects. For hybrid lists, individuals with DAT were 3 times more likely to recall the critical nonpresented word than a studied word. When false memory was considered as a proportion of veridical memory, there was an increase in relative false memory as a function of age and dementia. Results are discussed in terms of age- and dementia-related changes in attention and memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in retrieval: Trace-dependent and cue-dependent forgetting.

A multitrial free recall task was presented to 3 age groups of men and women (18-34, 50-64, and 65-83 yrs) under cued and noncued recall conditions to determine whether age-related differences in retrieval were attributable to the availability of elementary units (trace-dependent forgetting), the accessibility of higher order units (cue-dependent forgetting), or both. Results show significant age differences in words recalled, categories recalled (accessibility), and words recalled per category (availability). It is concluded that adult age differences in retrieval are a function of both cue-dependent and trace-dependent forgetting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are you sure you forgot? Feeling of knowing in directed forgetting.

One significant issue in metamemory is how variables increasing memorability affect metamemory. Previous research has produced inconsistent results. The effect of directed forgetting on the magnitude and accuracy of feeling-of-knowing (FOK) judgments was investigated. Participants were presented with word pairs, some to be remembered and some to be forgotten, and then were asked to recall all target words regardless of initial instructions. For unrecalled items, they were asked to give FOK judgments about performance in a future memory task: a cued stem-completion task (Experiment 1) or a recognition test (Experiment 2). This encoding manipulation increased both the memory performance and the magnitude of FOK judgments. However, no such effect on the accuracy of FOK judgments was observed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retrieval specificity and the attenuation of forgetting by testing.

Examined the effect of a single test trial on the rate of forgetting of word lists. 288 undergraduates studied a list of words and were given a recall test with weak associates as cues after either 10 min, 48 hrs, or 1 wk. Immediately after studying the list, Ss were tested with the same weak associates, different weak associates, or strong associates, or were dismissed without being tested. When the same cues were used on the 2 tests, recall performance did not deteriorate over time, but tests with different cues, whether strong or weak, had little effect on the rate of forgetting. Results suggest that a test can provide highly specific retrieval operations that compensate for the deterioration of the trace over time. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is there hypermnesia and reminiscence for information intentionally forgotten?

Memory performance was examined across consecutive tests in three directed-forgetting experiments. Following word-method or list-method cueing to forget, significant directed forgetting was observed for all tests: Free recall for remember cue words always exceeded free recall for forget cue words. Moreover, following either cueing method, similar magnitudes of hypermnesia (improved free recall across tests) and reminiscence (recovery of words across tests) were observed for both word types. Regardless of cueing method, after an initial free recall test, the level of recovery for both word types did not differ significantly. That is, directed forgetting was not observed for the reminiscence data. Taken together, the results suggest that cues to forget impair the encoding of information but, after an initial memory test, they do not interrupt the accessing of that information. These findings are consistent with the selective rehearsal account but not the retrieval inhibition account of directed forgetting. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of intentional forgetting in reducing children's retroactive interference.

Preschool and kindergarten children's retention of stories was examined in the presence of interfering information and instructions to forget. Children learned 2 stories and, 24 hr later, were asked to recall the 1st or 2nd story learned. Some of the children were instructed, either following acquisition or just prior to the retention test to forget the 2nd, or interfering, story. A model was used to isolate storage and retrieval effects, and the results showed that (a) retroactive interference affected both storage- and retrieval-based forgetting rates for the younger children but only storage-based forgetting rates for the older children, (b) intentional forgetting reduced retroactive interference primarily by attenuating storage-based forgetting regardless of age, (c) intentional forgetting instructions were effective only at acquisition for preschoolers but at both acquisition and retention for kindergarteners, and (d) all children recalled the to-be-forgotten story as well as they recalled the to-be-remembered story. These results are interpreted in terms of reorganization and distinctiveness effects in storage. (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)     

The role of spatial location in remembering and forgetting peripheral words.

This study examined whether spatial location mediates intentional forgetting of peripherally presented words. Using an item-method directed forgetting paradigm, words were presented in peripheral locations at study. A recognition test presented all words at either the same or a different location relative to study. Results showed that while recognition of Remember words was unaffected by test location, when Forget words were presented in the same location at test as at study, recognition accuracy was significantly greater than when presented in a different location. Experiment 2 showed that the speed to localize a previously studied word was faster when it was presented in the same rather than a different study-test location but that the magnitude of this spatial priming was unaffected by memory instruction. We suggest that the location of peripherally presented words is represented in memory and can aid the retrieval of poorly encoded words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of testing on the forgetting of related and unrelated associates.

Examined the rate of forgetting of experimentally acquired associative information when the to-be-associated items are either associatively related or related in semantic memory in 288 undergraduates. Separate groups of 24 Ss studied lists of word pairs in which the members of the pairs were either unrelated or strong or weak associates. A single study trial was given. In addition, 1 group received 3 study presentations on the unrelated list. An immediate cued recall test for half of the pairs was followed by a second test on all pairs either 10 min, 48 hrs, or 1 wk later. The associated pairs, both strong and weak, were forgotten less rapidly than the nonassociated pairs, but the effect was largely restricted to previously tested items. The results do not appear to be due to differences in the amount of interference present, but they point to the importance of retrieval operations in the attenuation of forgetting. (French abstract) (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling intrusions and correct recall in episodic memory: Adult age differences in encoding of list context.

A model for correct recall and intrusions in cued recall of word lists is introduced. Intrusions are false responses that were correct in an earlier list. The model assumes 3 exclusive states for memory traces after encoding: with a list tag (i.e., with information about list origin), without list tags, and missing. Across lists, a trace can lose its list tag or its content. For retrieval, an optimal strategy of response selection was assumed. Younger and older laboratory-trained mnemonists participated in 2 experiments in which recall of permutations of a single word list across a single set of cues was held constant with individually adjusted presentation times. With correct recall equated to younger adults, older adults were more susceptible to intrusions. Age differences were restricted to model parameters estimating the probability of generation of list tags. Alternative accounts of age differences in context memory are discussed. (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)