Modes of cognitive control in recognition and source memory: Depth of retrieval

Recognition memory is usually regarded as a judgment based on trace strength or familiarity. But recognition may also be accomplished by constraining retrieval so that only sought after information comes to mind (source-constrained retrieval). We introduce amemory-for-foils paradigm that provides evidence for source-constrained retrieval in recognition memory (Experiment 1) and source memory (Experiment 2). In this paradigm, subjects studied words under deep or shallow encoding conditions and were given a memory test (recognition or source) that required them to discriminate between new items (foils) and either deep or shallow targets. A final recognition test was used to examine memory for the foils. In both experiments, foil memory was superior when subjects attempted to retrieve deep rather than shallow targets on the earlier test. These findings support a sourceconstrained retrieval view of cognitive control by demonstrating qualitative differences in the basis for memory performance.     

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.     

Overestimation and contraction biases of depth information stored in working memory depend on spatial configuration

Depth perception is essential for effective interaction with the environment. Although the accuracy of depth perception has been studied extensively, it is unclear how accurate the depth information is stored in working memory. In this study, we investigated the accuracy and systematic biases of depth representation by a delayed estimation task. The memory array consisted of items presented at various stereoscopic depth positions, and the participants were instructed to estimate the depth position of one target item after a retention interval. We examined the effect of spatial configuration by comparing the memory performance in the whole-display condition where non-target memory items were present during retrieval with that in the single-display condition where non-target memory items were absent. In the single-display condition, we found an overestimation bias that the depth estimates were farther than the corresponding depth positions defined by disparity, and a contraction bias that the stored depth positions near the observer were overestimated and those far from the observer were underestimated. The magnitude of these biases increased with the number of to-be-stored items. However, in the whole-display condition, the overestimation bias was corrected and the contraction bias did not increase with the number of to-be-stored items. Our findings suggested that the number of to-be-stored items could affect the accuracy of depth working memory, and its effect depended crucially on whether the information of spatial configuration of memory display was available at the retrieval stage.     

Variations in constrained retrieval

Mentally reinstating encoding operations at retrieval might improve access to memories; however, such constrained retrieval is an effortful process that may not always be used. The memory-for-foils procedure (Jacoby, Shimizu, Daniels, & Rhodes, Psychonomic Bulletin & Review 12, 852-857, 2005) infers participant-initiated mental reinstatement of encoding operations during attempts at recognition from the differential memory that accrues to foils during a test of deeply processed items versus during a test of shallowly processed items, as indicated by performance on a final recognition memory test for the foils. Experiment 1 tested whether differential memory for foils is due to the evocation of task context during recollection of neighboring old items. Experiment 2 tested whether inducing a set to respond without much effort on a prior recognition test affects the likelihood of constrained retrieval on later tests. Experiment 3 tested whether constrained retrieval is less likely to occur when the deep versus shallow source of test items is intermixed, rather than blocked in separate tests. These experiments provide evidence that people query memory by mentally reinstating encoding operations and identify conditions that affect the probability of constrained retrieval.     

Working memory capacity predicts the beneficial effect of selective memory retrieval

Selective retrieval of some studied items can both impair and improve recall of the other items. This study examined the role of working memory capacity (WMC) for the two effects of memory retrieval. Participants studied an item list consisting of predefined target and nontarget items. After study of the list, half of the participants performed an imagination task supposed to induce a change in mental context, whereas the other half performed a counting task which does not induce such context change. Following presentation of a second list, memory for the original list's target items was tested, either with or without preceding retrieval of the list's nontarget items. Consistent with previous work, preceding nontarget retrieval impaired target recall in the absence of the context change, but improved target recall in its presence. In particular, there was a positive relationship between WMC and the beneficial, but not the detrimental effect of memory retrieval. On the basis of the view that the beneficial effect of memory retrieval reflects context-reactivation processes, the results indicate that individuals with higher WMC are better able to capitalise on retrieval-induced context reactivation than individuals with lower WMC.     

Retrieval-induced forgetting in implicit memory tests: The role of test awareness

Retrieval practice with particular items in memory may result in decreased recall of different, semantically related, items. This retrieval-induced forgetting effect has been demonstrated in studies using explicit memory tests. Anderson and Spellman (1995) have attributed retrieval-induced forgetting to inhibitory mechanisms. This hypothesis predicts similar effects in implicit memory tasks. In our first experiment, using Anderson and Spellman’s original paradigm, retrieval-induced forgetting was found using an explicit memory test with independent extralist retrieval cues. In our second experiment, using the same materials, retrieval-induced forgetting was also found using an implicit memory test with independent extralist retrieval cues, but only for participants who were aware of the relationship between the study and practice phase on the one hand, and the test phase of the experiment on the other. Thus, test awareness seems to mediate retrieval-induced forgetting in implicit memory tasks.     

Benefits from retrieval practice are greater for students with lower working memory capacity

We examined the effects of retrieval practice for students who varied in working memory capacity as a function of the lag between study of material and its initial test, whether or not feedback was given after the test, and the retention interval of the final test. We sought to determine whether a blend of these conditions exists that maximises benefits from retrieval practice for lower and higher working memory capacity students. College students learned general knowledge facts and then restudied the facts or were tested on them (with or without feedback) at lags of 0–9 intervening items. Final cued recall performance was better for tested items than for restudied items after both 10 minutes and 2 days, particularly for longer study–test lags. Furthermore, on the 2-day delayed test the benefits from retrieval practice with feedback were significantly greater for students with lower working memory capacity than for students with higher working memory capacity (r?=??.42). Retrieval practice may be an especially effective learning strategy for lower ability students.     

Applying an exemplar model to the artificial-grammar task: String completion and performance on individual items

Jamieson and Mewhort (2009a) demonstrated that performance in the artificial-grammar task could be understood using an exemplar model of memory. We reinforce the position by testing the model against data for individual test items both in a standard artificial-grammar experiment and in a string-completion variant of the standard procedure. We argue that retrieval is sensitive to structure in memory. The work ties performance in the artificial-grammar task to principles of explicit memory.     

Strategic retrieval processing and the impact of knowing when a memory was first created

Retrieval orientation refers to a process where participants strategically alter how a memory cue is processed in response to different task demands. In the present study we explored whether retrieval orientation is influenced by knowing when an old stimulus was first encoded. Participants completed separate remember/know test blocks for old items from a recent delay (40 min) and old items from a remote delay (48 h). Manipulations at encoding ensured that performance levels were matched between these two blocks, thus avoiding confounds with differences in retrieval effort. Importantly, a third test block comprised old items from both delays randomly intermixed. As the nature of the old items varies unpredictably in the mixed block, it should not be possibly to adopt a specific retrieval orientation and the mixed block therefore acts as a control condition. Participants saw the words “mixed,” “recent” or “remote” prior to each test block. Comparing ERPs from the recent and remote blocks permitted an investigation of whether participants alter their retrieval orientation in response to the specific length of the retention interval. Comparing ERPs from the pure (recent and remote) test blocks to ERPs from the mixed block permitted an investigation of whether delay information per se led to differences in retrieval strategy. Analysis of the ERP data found no differences between the recent and remote blocks. However, ERPs from these pure blocks were significantly less positive than ERPs from the mixed block from 200 ms towards the end of the epoch. The findings suggest that the delay information was useful in a general sense and encouraged retrieval strategies distinct from those engaged in the mixed block. We speculate that such strategies might relate to whether or not the retrieval search is specific and constrained and/or whether processes that serve to reinstate the original encoding context are engaged.     

Associative storage and retrieval processes in person memory

In this article, a general associative storage and retrieval theory of person memory is proposed, and seven experiments that test various aspects of the theory are reported. Experiment 1 investigated memory for behavioral information that is congruent with, incongruent with, or irrelevant to a prior impression. The results indicated that incongruent events are best recalled and irrelevant events are most poorly recalled. Experiment 2 replicated this effect and demonstrated that there are systematic individual differences that are consistent with the general nomothetic model proposed. The results of Experiment 3 indicated that, relative to a baseline condition, adding incongruent items to the list increases the probability of recalling congruent items but has no effect on the recall of irrelevant items. Both effects are predicted by the model. Experiment 4 provided support for the retrieval assumptions of the theory by demonstrating that there is a systematic order in which various types of items are recalled, as well as consistent differences in interresponse times. Experiments 5 and 6 demonstrated that the model is relevant to situations in which data driven, as well as conceptually driven, processes are involved. Finally, Experiment 7 examined a special case in which the theory predicts greater recall of congruent than incongruent behavioral events. The results of all seven experiments provide converging evidence for a general theory of person memory, and they have implications for a number of issues related to the study of person memory and social judgment.     

Hippocampal CA1 spiking during encoding and retrieval: relation to theta phase

The hippocampal theta rhythm is a prominent oscillation in the field potential observed throughout the hippocampus as a rat investigates stimuli in the environment. A recent computational model [Hasselmo, M. E., Bodelon, C., & Wyble, B. P. (2002a). A proposed function for hippocampal theta rhythm: separate phases of encoding and retrieval enhance reversal of prior learning. Neural Computation, 14, 793-817. Neuromodulation, theta rhythm and rat spatial navigation. Neural Networks, 15, 689-707] suggested that the theta rhythm allows the hippocampal formation to alternate rapidly between conditions that promote memory encoding (strong synaptic input from entorhinal cortex to areas CA3 and CA1) and conditions that promote memory retrieval (strong synaptic input from CA3 to CA1). That model predicted that the preferred theta phase of CA1 spiking should differ for information being encoded versus information being retrieved. In the present study, the spiking activity of CA1 pyramidal cells was recorded while rats performed either an odor-cued delayed nonmatch-to-sample recognition memory test or an object recognition memory task based on the animal's spontaneous preference for novelty. In the test period of both tasks, the preferred theta phase exhibited by CA1 pyramidal cells differed between moments when the rat inspected repeated (match) and non-repeated (nonmatch) items. Also in the present study, additional modeling work extended the previous model to address the mean phase of CA1 spiking associated with stimuli inducing varying levels of retrieval relative to encoding, ranging from novel nonmatch stimuli with no retrieval to highly familiar repeated stimuli with extensive retrieval. The modeling results obtained here demonstrated that the experimentally observed phase differences are consistent with different levels of CA3 synaptic input to CA1 during recognition of repeated 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。     

不同情绪背景下来源记忆的ERPs研究*

使用事件相关电位(ERP)技术和测试来源记忆的多键范式,探讨不同情绪效价背景下来源提取的认知神经机制。学习阶段,同时呈现汉字和3种效价情绪图片(重叠);测验阶段,只呈现汉字,要求被试进行四键判断：旧字且背景为中性,旧字且背景为正性,旧字且背景为负性,新字。结果发现：在提取阶段,刺激呈现后300~500 ms,3种情绪背景下来源判断正确项目和来源判断错误项目都比新项目诱发了更正的ERPs(即都存在新旧效应),这一结果反映出刺激呈现后300~500 ms 是一个早期的项目提取阶段,它独立于来源提取。并且,在中性背景下,两种新旧效应没有差别;而在正性和负性背景下,来源判断正确项目的新旧效应显著大于来源判断错误项目。说明相比于中性背景,情绪背景下被试可能更早对来源信息产生熟悉感。在500~650 ms,3种情绪背景下都存在来源判断正确项目的新旧效应,在来源判断错误项目和新项目之间没有显著差异,来源正确与来源错误有显著的新旧效应差异,但二者在头皮分布上是类似的,这反映了晚期的来源提取过程。同时来源正确的新旧效应在这两个时段有显著不同的头皮分布,表明这两个时段有不同加工过程。另外,在500~650 ms,存在显著的情绪效应,正性背景下正确判断来源诱发的ERPs比中性和负性背景下的更正,而且来源判断错误条件下没有情绪效应。综上所述,来源正确和来源错误可能仅仅反映了大脑激活在量上的不同,并不能推断两者存在质的差异;大脑神经活动的早期不仅反映了对记忆项目的熟悉性,而且也受情绪效应的影响,500 ms之后大脑神经活动反映的是对记忆项目回想的过程,这一回想过程也与情绪效应有关,受到情绪效应的调节。     

Memory retrieval as a self-propagating process

Retrieval of a subset of studied items and the presentation of those items as retrieval cues typically impair retrieval of the other items. Previous research on this self-limiting property of memory retrieval has relied heavily on short retention intervals and similar context between encoding and test. Here, we examined retrieval dynamics also after a prolonged retention interval with different spatial and social context between encoding and test, conditions that mimic people’s remembering in many situations of daily life. For both unrelated word lists and more integrated prose material, we found retrieval and cuing to impair recall of other studied items after a short retention interval, but to improve recall in the prolonged retention interval condition. The results demonstrate that retrieval dynamics depend critically on situation, indicating that quite often in daily life, retrieval may be a self-propagating, rather than a self-limiting process.     

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.     

The effects of delay and interference: A speed-accuracy study

This paper examines the effect of (1) delay between learning and test and (2) associative interference on memory retrieval speed. The speed-accuracy tradeoff methodology, which interrupts the retrieval process at various times (0.3, 0.7, 1.0, 1.5, 2.0, and 3.0 sec) after presentation of the test item, provides a means of separating retrieval speed effects from effects on overall memory strength. Performance at short processing times is an index of retrieval speed. Performance given ample processing time is a measure of asymptotic accuracy, or memory strength. Increasing the delay between learning and test or introduction of interference relations lowered memory trace strength, as reflected in asymptotic accuracy. Items tested shortly (about 3 sec) after learning showed a significant speedup in retrieval relative to items tested at a longer (several minute) delay. Further analysis suggested that the delay effect on retrieval was primarily the result of immediate repetition, or testing of the last-learned item. The interference manipulation showed a slight and nonsignificant tendency toward slowing of memory retrieval. The implications of these results for various models of retrieval are explored via simulations. The results of all the simulations suggested a direct-access retrieval process where associations are processed largely in parallel. Contradiction or mismatch information in recognizing new items was important because it provided an explanation for a slight slowing in retrieval due to interference even with a parallel-processing assumption. Faster retrieval for the last-learned item may be the result of residual activation following active processing.     

Neutral details associated with emotional events are encoded: evidence from a cued recall paradigm

Enhanced emotional memory often comes at the cost of memory for surrounding background information. Narrowed-encoding theories suggest that this is due to narrowed attention for emotional information at encoding, leading to impaired encoding of background information. Recent work has suggested that an encoding-based theory may be insufficient. Here, we examined whether cued recall—instead of previously used recognition memory tasks—would reveal evidence that non-emotional information associated with emotional information was effectively encoded. Participants encoded positive, negative, or neutral objects on neutral backgrounds. At retrieval, they were given either the item or the background as a memory cue and were asked to recall the associated scene element. Counter to narrowed-encoding theories, emotional items were more likely than neutral items to trigger recall of the associated background. This finding suggests that there is a memory trace of this contextual information and that emotional cues may facilitate retrieval of this information.     

The role of inhibitory control in forgetting semantic knowledge

Previous research has shown that episodic retrieval recruits inhibitory processes that impair memory for related events. We report two experiments examining whether inhibitory processes may also be involved in causing semantic memory lapses. In a semantic retrieval-practice paradigm, subjects were given trials presenting a cue (a homograph in Experiment 1, a category in Experiment 2) linked to many different items in semantic memory. For each cue, subjects used general knowledge to generate no (baseline), one, four, or eight different items of semantic knowledge. Afterward, we determined through an apparently unrelated free-association test whether a critical nonpracticed concept associated to the cue had been inhibited. Both experiments found that generating items from semantic memory suppressed competing concepts, and that this impairment was cue independent. These findings show that inhibitory control processes overcome interference during semantic retrieval and that recruitment of these processes may contribute to semantic forgetting.     

The effect of context variability on source memory

High-context-variability (HCV) items are experienced in many more preexperimental semantic contexts than are low-context-variability (LCV) items. LCV confers an advantage to recognition memory (Steyvers & Malmberg, 2003). In the present study, we tested whether or not that advantage could be causedby enhanced source memory. Both context variability and word frequency were manipulated, and both factors generally affected source monitoring. Accuracy was better for LCV items than for HCV items and better for low- than for high-word-frequency items. We also considered whether context variability exerts its influence at encoding or at retrieval. We concluded that better recognition memory for LCV items was due, in part, to better retrieval of contextual details that specify how an item was originally studied.