Directed forgetting and aging: the role of retrieval processes, processing speed, and proactive interference

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items.     

Directed Forgetting and Aging: The Role of Retrieval Processes,Processing Speed,and Proactive Interference

ABSTRACT

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items.     

Interference processes in monkey auditory list memory

A rhesus monkey’s memory was tested for single items and four-item lists of natural and environmental sounds. Memory items were presented from a center speaker, followed by a retention delay and then a choice response to a test sound presented simultaneously from two side speakers. Recognition of the last item of four-item lists was much poorer than that of single items at 0-, 1-, and 2-sec delays, despite there being the same temporal relations between study and test. This result showed that the first three items proactively interfered with memory of the last list item. Proactive interference dissipated after 2 sec, revealing a recency effect that eventually equaled single-item performance. Recognition of the first item of four-item lists was much poorer than single items at 20- and 30-sec delays, showing that the last three items retroactively interfered with memory of the first list item. The results point to the critical nature of interference processes in the understanding of serial position functions.     

An experimental analysis of memory processing

Rhesus monkeys were trained and tested in visual and auditory list-memory tasks with sequences of four travel pictures or four natural/environmental sounds followed by single test items. Acquisitions of the visual list-memory task are presented. Visual recency (last item) memory diminished with retention delay, and primacy (first item) memory strengthened. Capuchin monkeys, pigeons, and humans showed similar visual-memory changes. Rhesus learned an auditory memory task and showed octave generalization for some lists of notes--tonal, but not atonal, musical passages. In contrast with visual list memory, auditory primacy memory diminished with delay and auditory recency memory strengthened. Manipulations of interitem intervals, list length, and item presentation frequency revealed proactive and retroactive inhibition among items of individual auditory lists. Repeating visual items from prior lists produced interference (on nonmatching tests) revealing how far back memory extended. The possibility of using the interference function to separate familiarity vs. recollective memory processing is discussed.     

线索强度对提取练习效应的影响机制：来自ERP的证据

运用事件相关电位技术,探讨提取练习和精细加工在不同线索强度上的加工方式有何不同。结果显示：强线索词对下,二者的相继记忆效应未出现显著性的分离,出现500-700ms额叶、中央分布的模式;弱线索词对下,二者的相继记忆效应出现分离,提取条件500-700ms,700-1000ms观察到与晚期顶叶成分相似的相继记忆效应,精细加工下并没有。结果表明：提取强线索词时个体的加工方式与精细加工类似,提取弱线索词时与精细加工不同,支持情境背景理论。     

Time does not cause forgetting in short-term serial recall

Time-based theories expect memory performance to decline as the delay between study and recall of an item increases. The assumption of time-based forgetting, central to many models of serial recall, underpins their key behaviors. Here we compare the predictions of time-based and event-based models by simulation and test them in two experiments using a novel manipulation of the delay between study and retrieval. Participants were trained, via corrective feedback, to recall at different speeds, thus varying total recall time from 6 to 10 sec. In the first experiment, participants used the keyboard to enter their responses but had to repeat a word (called the suppressor) aloud during recall to prevent rehearsal. In the second experiment, articulation was again required, but recall was verbal and was paced by the number of repetitions of the suppressor in between retrieval of items. In both experiments, serial position curves for all retrieval speeds overlapped, and output time had little or no effect. Comparative evaluation of a time-based and an event-based model confirmed that these results present a particular challenge to time-based approaches. We conclude that output interference, rather than output time, is critical in serial recall.     

Adaptive memory: The influence of sleep and wake delay on the survival-processing effect

Processing items in terms of their survival value leads to superior memory relative to many deep (semantic) processing tasks. To date, such survival processing has been investigated with short delay intervals only, ignoring possible effects of longer wake and sleep delay. In this study, subjects performed orienting tasks that induced survival or deep (semantic) processing of single items. A surprise memory test was administered after a short delay or a delay of 12 hours that included either sleep or wake; a cued-recall test was conducted in Experiment 1, and an item-recognition test in Experiment 2. Survival-processing effects were present regardless of delay, and their size was not influenced by delay interval. While wake delay reduced memory for both item types, sleep compared to wake enhanced their memory. These results suggest that the survival-processing effect is fully maintained across longer delay, regardless of whether the interval is filled with wake or sleep.     

The influence of retrieval on retention

Four experiments tested the hypothesis that successful retrieval of an item from memory affects retention only because the retrieval provides an additional presentation of the target item. Two methods of learning paired associates were compared. In the pure study trial (pure ST condition) method, both items of a pair were presented simultaneously for study. In the test trial/study trial (TTST condition) method, subjects attempted to retrieve the response term during a period in which only the stimulus term was present (and the response term of the pair was presented after a 5-sec delay). Final retention of target items was tested with cued-recall tests. In Experiment 1, there was a reliable advantage in final testing for nonsense-syllable/number pairs in the TTST condition over pairs in the pure ST condition. In Experiment 2, the same result was obtained with Eskimo/English word pairs. This benefit of the TTST condition was not apparently different for final retrieval after 5 min or after 24 h. Experiments 3 and 4 ruled out two artifactual explanations of the TTST advantage observed in the first two experiments. Because performing a memory retrieval (TTST condition) led to better performance than pure study (pure ST condition), the results reject the hypothesis that a successful retrieval is beneficial only to the extent that it provides another study experience.     

Time-limited effects of emotional arousal on item and source memory

Two experiments investigated the time-limited effects of emotional arousal on consolidation of item and source memory. In Experiment 1, participants memorized words (items) and the corresponding speakers (sources) and then took an immediate free recall test. Then they watched a neutral, positive, or negative video 5, 35, or 50?min after learning, and 24 hours later they took surprise memory tests. Experiment 2 was similar to Experiment 1 except that (a) a reality monitoring task was used; (b) elicitation delays of 5, 30, and 45?min were used; and (c) delayed memory tests were given 60?min after learning. Both experiments showed that, regardless of elicitation delay, emotional arousal did not enhance item recall memory. Second, both experiments showed that negative arousal enhanced delayed item recognition memory only at the medium elicitation delay, but not in the shorter or longer delays. Positive arousal enhanced performance only in Experiment 1. Third, regardless of elicitation delay, emotional arousal had little effect on source memory. These findings have implications for theories of emotion and memory, suggesting that emotion effects are contingent upon the nature of the memory task and elicitation delay.     

Cortisol and stimulus-induced arousal level differentially impact memory for items and backgrounds

Most studies examine the effects of stress on memory for visual information test memory for entire scenes. However, arousal levels may differentially influence memory for backgrounds as opposed to items. Participants encoded scenes that included a negative-high-arousal, negative-moderate-arousal, or neutral item on a neutral background. After a 30-minute (Experiment 1) or 48-hour delay (Experiment 2), participants underwent a stressor or control task while heart rate was recorded. A recognition memory task was then given with items and backgrounds presented separately. High-arousal images had a greater detriment in background memory than moderate-arousal images. Further, though there was evidence that change in cortisol level at retrieval was associated with impaired memory for items, it was not associated with detriments in background memory. Increased heart rate was associated with impaired memory for both items and backgrounds. This suggests that the level of sympathetic and cortisol reactivity differentially affects memory for items and backgrounds.     

提取诱发遗忘：项目强度与测试顺序的影响

提取诱发遗忘是指对先前学过的部分材料进行提取练习会使与练习材料相关的其它材料发生遗忘。目前该现象存在抑制与非抑制理论之争。本研究以64名大学生为被试,通过考察项目强度和测试顺序对提取诱发遗忘的影响,对上述争论进行了探讨。结果表明：（1）只有高强度项目才会引发提取诱发遗忘;（2）当控制由测试顺序所产生的输出干扰效应后,高强度项目仍然会引发提取诱发遗忘。本研究结果支持了提取诱发遗忘的抑制理论。     

Cue Combinatorics in Memory Retrieval for Anaphora

Many studies have shown that memory retrieval for real‐time language processing relies on a cue‐based access mechanism, which allows the cues available at the retrieval site to directly access the target representation in memory. An open question is how different types of cues are combined at retrieval to create a single retrieval probe (“cue combinatorics”). This study addresses this question by testing whether retrieval for antecedent‐reflexive dependencies combines cues in a linear (i.e., additive) or nonlinear (i.e., multiplicative) fashion. Results from computational simulations and a reading time experiment show that target items that match all the cues of the reflexive are favored more than target items that mismatch these cues, and that different degrees of mismatches slow reading times in comparable amounts. This profile is consistent with the predictions of a nonlinear cue combination and provides evidence against models in which all cues combine in a linear fashion. A follow‐up set of simulations shows that a nonlinear rule also captures previous demonstrations of interference from nontarget items during retrieval for reflexive licensing. Taken together, these results shed new light on how different types of cues combine at the retrieval site and reveal how the method of cue combination impacts the accessibility of linguistic information in memory.     

Repeated retrieval practice and item difficulty: Does criterion learning eliminate item difficulty effects?

A wealth of previous research has established that retrieval practice promotes memory, particularly when retrieval is successful. Although successful retrieval promotes memory, it remains unclear whether successful retrieval promotes memory equally well for items of varying difficulty. Will easy items still outperform difficult items on a final test if all items have been correctly recalled equal numbers of times during practice? In two experiments, normatively difficult and easy Lithuanian–English word pairs were learned via test–restudy practice until each item had been correctly recalled a preassigned number of times (from 1 to 11 correct recalls). Despite equating the numbers of successful recalls during practice, performance on a delayed final cued-recall test was lower for difficult than for easy items. Experiment 2 was designed to diagnose whether the disadvantage for difficult items was due to deficits in cue memory, target memory, and/or associative memory. The results revealed a disadvantage for the difficult versus the easy items only on the associative recognition test, with no differences on cue recognition, and even an advantage on target recognition. Although successful retrieval enhanced memory for both difficult and easy items, equating retrieval success during practice did not eliminate normative item difficulty differences.     

Hemispheric memory for random forms revisited

Hemispheric short-term memory was studied by projecting complex random forms that varied in their verbal association strength to the left and right hemispheres. Male and female subjects responded same or different to a centrally presented memory test stimulus which occurred 0, 5, 10, or 20 sec after the target item. Reaction time for both response judgments was significantly shorter for right-hemisphere presentations over all memory intervals. For both performance measures, response judgment interacted with the length of memory interval and the verbal association value of the stimulus items. No hemispheric differences were observed as a function of subject sex. Hemispheric memory for complex forms appears primarily dependent upon task processing demands rather than stimulus factors when response time is used to measure recognition under tightly controlled conditions.     

Strong items get suppressed, weak items do not: The role of item strength in output interference

An experiment is reported that examines the role of item strength in output interference. Subjects studied two types of categorized item lists: lists in which each category consisted of strong and moderate items, and lists in which each category consisted of weak and moderate items. Different degrees of item strength were accomplished by varying the items’ taxonomic frequency within a category. The subjects either recalled a category’s strong and weak items before its moderate items, or vice versa. The prior recall of the moderate items impaired the later recall of the strong items, but did not impair the later recall of the weak items. This effect of item strength indicates that output interference is caused by a process of retrieval suppression. It additionally suggests that, in order to minimize output-interference effects in recall, a list’s strong items should be recalled before its weak items.     

提取过程越久记忆保持越好吗？材料难度的调节作用

提取练习效应揭示了提取对记忆保持的关键意义;学习时间分配的有关研究表明提取练习效应的大小可能与材料难度有关。两个实验探讨了提取时间与材料难度对提取练习效应的影响：实验1采用2（提取时间：短,长）×2（材料难度：容易,困难）的混合设计,5分钟后测查记忆保持水平。实验2采用类似设计,将最终测试间隔延长至24小时。结果发现,⑴ 延长提取时间均提高了记忆成绩和记忆保持率。⑵ 即时测试条件下,提取时间较短时,不同难度材料的记忆成绩差异不显著;提取时间较长时,困难材料的记忆成绩高于容易材料;困难材料的记忆保持率在不同提取时间下均高于容易材料。⑶ 延迟测试条件下,无论提取时间长短,困难材料的记忆成绩及保持率均高于容易材料。研究表明,延长提取时间对提取练习效应的影响受材料难度的调节;情境背景和必要难度是解释该调节作用的可能理论框架。     

Selective memories: infants' encoding is enhanced in selection via suppression

The present study examined the hypothesis that inhibitory visual selection mechanisms play a vital role in memory by limiting distractor interference during item encoding. In Experiment 1a we used a modified spatial cueing task in which 9‐month‐old infants encoded multiple category exemplars in the contexts of an attention orienting mechanism involving suppression (i.e. inhibition of return, IOR) versus one that does not (i.e. facilitation). At test, infants in the IOR condition showed both item‐specific learning and abstraction of broader category information. In contrast, infants in the facilitation condition did not discriminate across novel and familiar test items. Experiment 1b confirmed that the learning observed in the IOR condition was specific to spatial cueing of attention and was not due to timing differences across the IOR and facilitation conditions. In Experiment 2, we replicated the results of Experiment 1, using a within‐subjects design to explicitly examine learning and memory encoding in the context of concurrent suppression. These data show that developing inhibitory selective attention enhances efficacy of memory encoding for subsequent retrieval. Furthermore, these results highlight the importance of considering interactions between developing attention and memory systems.     

Emotion, directed forgetting, and source memory

We investigated the role of emotion on item and source memory using the item method of directed forgetting (DF) paradigm. We predicted that emotion would produce source memory impairment because emotion would make it more difficult to distinguish between to-be-remembered (R items) and to-be-forgotten items (F items) by making memory strength of R and F items similar to each other. Participants were presented with negatively arousing, positively arousing, and neutral pictures. After each picture, they received an instruction to remember or forget the picture. At retrieval, participants were asked to recall both R and F items and indicate whether each item was an R or F item. Recall was higher for the negatively arousing than for the positively arousing or neutral pictures. Further, DF occurred for the positively arousing and neutral pictures, whereas DF was not significant for the negatively arousing pictures. More importantly, the negatively arousing pictures, particularly the ones with violent content, showed a higher tendency of producing misattribution errors than the other picture types, supporting the notion that negative emotion may produce source memory impairment, even though it is still not clear whether the impairment occurs at encoding or retrieval.     

单字法有意遗忘的内部心理机制：基于多项式加工树模型的分析

通过构建使用单个双字词作为实验材料,并在测验阶段全面考察记忆提取过程的MPT模型,考察单字法有意遗忘的心理机制。结果发现,对于TBF/R项目,遗忘组的储存能力和提取能力均弱于记忆组;对于TBR/R项目,遗忘组的储存能力强于记忆组。并且无论对于短时SOA还是长时SOA,遗忘组对TBF项目后探测刺激的反应时都显著长于TBR项目。研究表明,单字法有意遗忘现象是由选择性复述、注意抑制和提取抑制三种机制共同作用的结果。     

Serial-position effects for items and relations in short-term memory

Two experiments used immediate probed recall of words to investigate serial-position effects. Item memory was tested through probing with a semantic category. Relation memory was tested through probing with the word's spatial location of presentation. Input order and output order were deconfounded by presenting and probing items in different orders. Primacy and recency effects over input position were found for both item memory and relation memory. Both item and relation memory declined over output position. The finding of a U-shaped input position function for item memory rules out an explanation purely in terms of positional confusions (e.g., edge effects). Either these serial-position effects arise from variations in the intrinsic memory strength of the items, or they arise from variations in the strength of item–position bindings, together with retrieval by scanning.