The "One-Shot" Hypothesis for Context Storage.

In 3 experiments motivated by the implicit memory literature, the authors investigated the effects of different strengthening operations on the list strength effect (LSE) for explicit free recall, an effect posited by R. M. Shiffrin, R. Ratcliff, and S. E. Clark (1990) to be due to context cuing. According to the one-shot hypothesis, a fixed amount of context is stored when an item is studied for at least 1 or 2 s. Beyond the initial context storage, increases in study time or different orienting tasks do not influence the amount of context that is stored, and thus only spaced repetitions should produce a positive LSE. Consistent with prior findings, spaced repetitions always produced a positive LSE, but increases in depth of processing, study time, and massed repetitions did not. A model implements the one-shot hypothesis, and a role for context storage as a link between episodic and semantic memory is discussed. (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)     

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)     

The role of item strength in retrieval-induced forgetting.

In 3 experiments, the role of item strength in the retrieval-induced forgetting paradigm was tested. According to the inhibition theory of forgetting proposed by M. C. Anderson, R. A. Bjork, and E. L. Bjork (1994), retrieval-induced forgetting should be larger for items that are more strongly associated with the category cue. In the present experiments, the authors varied item strength on the study list by manipulating the position of an item within its category (Experiments 1 and 2) and by the number of presentations in the study phase (Experiment 3). Contrary to the predictions from inhibition theory, in all 3 experiments, stronger items did not show more retrieval-induced forgetting than weaker items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of changes in relative cue strength on context-dependent recognition.

Theoretical analyses and empirical studies address the issue of how context-dependent recognition is affected by changes in the relative strength of retrieval cues. Analyses of global memory models based on K. Murnane and M. P. Phelps' (1994) general context model showed that if context strength is held constant, context effects are predicted to either increase or remain unchanged when item strength increases. In contrast, the outshining hypothesis (S. M. Smith, 1988, 1994) predicts that context effects will decrease as item strength increases. Three studies are reported in which item strength was manipulated with spaced repetitions, study time, or a levels-of-processing manipulation. The results support the general context model. Implications for the outshining hypothesis and for global memory models are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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

No retrieval-induced forgetting using item-specific independent cues: Evidence against a general inhibitory account.

Retrieval practice with particular items from memory can impair the recall of related items on a later memory test. This retrieval-induced forgetting effect has been ascribed to inhibitory processes (M. C. Anderson & B. A. Spellman, 1995). A critical finding that distinguishes inhibitory from interference explanations is that forgetting is found with independent (or extralist) cues. In 4 experiments, the authors tested whether the forgetting effect is cue-independent. Forgetting was investigated for both studied and unstudied semantically related items. Retrieval-induced forgetting was not found using item-specific independent cues for either studied or unstudied items. However, forgetting was found for both item types when studied categories were used as cues. These results are not in line with a general inhibitory account, because this account predicts retrieval-induced forgetting with independent cues. Interference and context-specific inhibition are discussed as possible explanations for the data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A global theory of remembering and forgetting from multiple lists.

Forgetting is frustrating, usually because it is unintended. Other times, one may purposely attempt to forget an event. A global theory of recognition and free recall that explains both types of forgetting and remembering from multiple list experiments is presented. The critical assumption of the model is that both intentional and unintentional forgetting are often due to contextual interference. Unintentional forgetting is the natural result of contextual changes between study and test. Intentional forgetting is accomplished by a rapid, metacognitively instigated change in mental context that renders to-be-forgotten information relatively inaccessible and renders to-be-remembered information more accessible (L. Sahakyan & C. M. Kelley, 2002). This occurs for both recognition and free recall. Implications for item-method directed forgetting, exclusion recognition, source memory, and encoding operations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studies of directed forgetting in older adults

Younger and older adults were compared in 4 directed forgetting experiments. These varied in the use of categorized versus unrelated word lists and in the use of item by item versus blocked remember-forget cueing procedures. Consistent with L. Hasher and R. T. Zacks's (1988) hypothesis of impaired inhibitory mechanisms in older adults, a variety of findings indicated that this age group is less able than younger adults to suppress the processing and retrieval of items designated as to be forgotten (TBF). Specifically, in comparison with younger adults, older adults produced more TBF word intrusions on an immediate recall test (Experiments 1A and 1B), took longer to reject TBF items (relative to a neutral baseline) on an immediate recognition test (Experiment 3), and recalled (Experiments 1A, 1B, and 2) and recognized (Experiment 1B and 2) relatively more TBF items on delayed retention tests in which all studied items were designated as targets.     

Double take: Parallel processing by the cerebral hemispheres reduces attentional blink.

Recent data have shown that parallel processing by the cerebral hemispheres can expand the capacity of visual working memory for spatial locations (J. F. Delvenne, 2005) and attentional tracking (G. A. Alvarez & P. Cavanagh, 2005). Evidence that parallel processing by the cerebral hemispheres can improve item identification has remained elusive. The authors used a novel variant of the attentional blink paradigm to show that the attentional blink is reduced if targets are divided between the hemispheres rather than directed to a single hemisphere. Parallel processing by the cerebral hemispheres can thus expand the capacity of processes involved in item identification. The authors also show that prior engagement of the attentional system may compromise the processing of items directed to the right visual field. This pseudoextinction may explain the failures of previous attempts to demonstrate that parallel processing can improve item identification (J. F. Delvenne, 2005; S. J. Luck, S. A. Hillyard, G. R. Mangun, & M. S. Gazzaniga, 1989). (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)     

Theoretical implications of extralist probes for directed forgetting.

In 5 experiments, the authors examined the influence of associative information in list-method directed forgetting, using the extralist cuing procedure (Nelson & McEvoy, 2005). Targets were studied in the absence of cues, but during retrieval, related cues were used to test their memory. Experiment 1 manipulated the degree of resonant connections from associates of the target back to the target. Experiment 2 varied the degree of connectivity of associates of the target. Experiment 3 varied the size of the associative neighborhood of the target. Experiment 4 varied the direct target-to-cue strength, and Experiment 5 varied the indirect strength between the cue and the target. Reliable directed forgetting impairment emerged in all experiments. Furthermore, directed forgetting reduced the effects of the associates contributing to the target activation strength (Experiments 1–2), and it also reduced the effects of the associates contributing to the cue–target intersection strength (Experiments 3–5). Together, these results support the context account and challenge the inhibitory interpretation of directed forgetting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of forgetting rate in producing a benefit of expanded over equal spaced retrieval in young and older adults.

The current study examined the effects of two manipulations on equal and expanded spaced retrieval schedules in young and older adults. First, we examined the role that the type of expansion (systematic vs. nonsystematic) has in producing a benefit of expanded retrieval. Second, we examined the influence of an immediate retrieval attempt to minimize forgetting after the original encoding event. It was predicted that including multiple retrieval attempts with minimal intervening spacing (best accomplished in a nonsystematic retrieval schedule) would be necessary to produce a benefit of expanded retrieval over equal spaced retrieval for older adults but not young adults due to age differences in working memory capacity. Results from two experiments revealed that the presence of an expanded over equal spaced retrieval benefit is modulated by the extent to which the spacing conditions minimize forgetting in the early retrieval attempts in the spaced conditions. As predicted, these conditions differ substantially across young and older adults. In particular, in older adults two intervening items between early retrieval attempts produce dramatic rates of forgetting compared to one intervening item, whereas younger adults can maintain performance up to five intervening events in comparable conditions. Discussion focuses on age differences in short term forgetting, working memory capacity, and the relation between forgetting rates and spaced retrieval schedules. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Encoding conditions and the list-strength effect.

The list-strength effect occurs when "strong" items within a list are remembered at the expense of "weak" items within that same list. Two experiments (using 185 college student Ss) showed that variably encoded words were remembered better than words repeated with the same encoding context, whether memory was measured by free recall, frequency estimates, or recognition d'. However, there was little or no evidence from any of the measures that the variably encoded words were recollected in the mixed lists at the expense of the similarly encoded words. This pattern held even though, in Exp 2, there was a list-strength effect on free recall, when list strength was manipulated by increasing the number of presentations of a word. It is concluded that the free recall results could not be accommodated by the model of memory postulated by R. M. Shiffrin et al (see record 1990-13917-001) to account for the effects of list strength. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When does generation enhance memory for location?

Generation is thought to enhance both item-specific and relational processing of generated targets as compared with read words (M. A. McDaniel & P. J. Waddill, 1990). Generation facilitates encoding of the cue-target relation and sometimes boosts encoding of relations across list items. Of interest is whether generation can also increase the encoding of target-location associations. Because the literature on this point is mixed, 3 procedural differences between 2 studies (E. J. Marsh, G. Edelman, & G. H. Bower, 2001; N. W. Mulligan, 2004) were identified and manipulated. A positive generation effect was found for location memory, but this effect was reduced when subjects wrote down the study words and when the filler task involved generation. Generation can enhance location memory in addition to item memory but only if the experimental parameters do not interfere with the processing benefits of generation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correction to Jarrold et al. (2011).

Reports an error in "How does processing affect storage in working memory tasks? Evidence for both domain-general and domain-specific effects" by Christopher Jarrold, Helen Tam, Alan D. Baddeley and Caroline E. Harvey (Journal of Experimental Psychology: Learning, Memory, and Cognition, , , np). Chen and Cowan (2009) is correctly cited in the body of the article but the reference at the end of the article is incorrect. The correct reference is in the correction. (The following abstract of the original article appeared in record 2011-02787-001.) Two studies that examine whether the forgetting caused by the processing demands of working memory tasks is domain-general or domain-specific are presented. In each, separate groups of adult participants were asked to carry out either verbal or nonverbal operations on exactly the same processing materials while maintaining verbal storage items. The imposition of verbal processing tended to produce greater forgetting even though verbal processing operations took no longer to complete than did nonverbal processing operations. However, nonverbal processing did cause forgetting relative to baseline control conditions, and evidence from the timing of individuals' processing responses suggests that individuals in both processing groups slowed their responses in order to “refresh” the memoranda. Taken together the data suggest that processing has a domain-general effect on working memory performance by impeding refreshment of memoranda but can also cause effects that appear domain-specific and that result from either blocking of rehearsal or interference. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Directed forgetting: Comparing pictures and words.

The authors investigated directed forgetting as a function of the stimulus type (picture, word) presented at study and test. In an item-method directed forgetting task, study items were presented 1 at a time, each followed with equal probability by an instruction to remember or forget. Participants exhibited greater yes–no recognition of remember than forget items for each of the 4 study–test conditions (picture–picture, picture–word, word–word, word–picture). However, this difference was significantly smaller when pictures were studied than when words were studied. This finding demonstrates that the magnitude of the directed forgetting effect can be reduced by high item memorability, such as when the picture superiority effect is operating. This suggests caution in using pictures at study when the goal of an experiment is to examine potential group differences in the magnitude of the directed forgetting effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On recollections lost: When practice makes imperfect.

Recent research has demonstrated that the act of remembering can prompt forgetting or, more specifically, the inhibition of specific items in memory (M. C. Anderson & B. A. Spellman, 1995). This line of inquiry was extended through an investigation of the process and consequences of retrieval-induced forgetting in social cognition. Across 3 studies, the findings clarify several unresolved issues in the psychology of forgetting. First, it was demonstrated that retrieval-induced forgetting extends to issues in social cognition (Experiment 1). Second, forgetting can be elicited even in task contexts in which perceivers are highly motivated to remember the presented material (Experiment 2). Third, forgetting is not moderated by the amount of retrieval practice that perceivers experience (Experiment 3). These findings are considered in the context of recent treatments of cognitive inhibition and goal-directed forgetting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rehearsal strategies can enlarge or diminish the spacing effect: Pure versus mixed lists and encoding strategy.

Using 5 experiments, the authors explored the dependency of spacing effects on rehearsal patterns. Encouraging rehearsal borrowing produced opposing effects on mixed lists (containing both spaced and massed repetitions) and pure lists (containing only one or the other), magnifying spacing effects on mixed lists but diminishing spacing effects on pure lists. Rehearsing with borrowing produced large spacing effects on mixed lists but not on pure lists for both free recall (Experiment 1) and recognition (Experiment 2). In contrast, rehearsing only the currently visible item produced spacing effects on both mixed lists and pure lists in free recall (Experiment 3) and recognition (Experiment 4). Experiment 5 demonstrated these effects using a fully within-subjects design. Rehearse-aloud protocols showed that rehearsal borrowing redistributed study from massed to spaced items on mixed lists, especially during massed presentations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metacognitive control over the distribution of practice: When is spacing preferred?

The authors clarify the source of a conflict between previous findings related to metacognitive control over the distribution of practice. In a study by L. Son (2004), learners were initially presented pairs of Graduate Record Examination (GRE) vocabulary words and their common synonyms for 1 s, after which they chose to study the pair again immediately (massed practice), later (spaced practice), or not at all (done). Learners chose spaced practice less as pair difficulty increased. A. S. Benjamin and R. D. Bird (2006), using different materials and procedures and a longer presentation duration (5 s), concluded just the opposite. The authors adopted Son’s materials and procedures and replicated her findings with a 1-s stimulus duration. However, the declining choice of spacing as item difficulty increased largely reflected learners’ failure to fully perceive items with brief presentations. With longer presentations, ensuring full perception, the choice of spaced practice increased with greater pair difficulty, in agreement with Benjamin and Bird. Theoretical implications are discussed in the context of discrepancy-reduction and proximal-learning perspectives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)