Directed search through autobiographical memory

Two experiments were designed to study retrieval from a well-ordered set of overlearned information in long-term autobiographical memory. In Experiment 1, each of 161 university students was asked to recall the name of one teacher from each of the 12 preuniversity school years. Recall was cued in forward (Grades 1-12), backward (Grades 12-1), or random order. Backward-ordered search proved most efficient: Fewer students failed to complete the task :in that search order, and those who did complete the task were faster than the successful students in the other search orders. Experiment 2 was similar to Experiment 1, except that the 148 students tested were asked to “think aloud” as they attempted recall. From the resulting protocols, 25 categories of verbal reports were identified, including four that reflected retrieval strategies. Omission errors (failures to recall teachers’ names) and, with one exception, frequencies of verbal reports decreased as recency increased. Taken together, the results of both experiments show that the recall of one item can indirectly aid the recall of contiguous items and that the probability of recalling an item from autobiographical memory is primarily a function of recency.     

Memory search and the neural representation of context

A challenge for theories of episodic memory is to determine how we focus memory search on a set of recently learned items. Cognitive theories suggest that the recall of an item representation is driven by an internally maintained context representation that integrates incoming information with a long time-scale. Neural investigations have shown that recalling an item revives the pattern of brain activity present during its study. To link these neural and cognitive approaches, we propose a framework in which context is maintained and updated in prefrontal cortex, and is associated with item information through hippocampal projections. The proposed framework is broadly consistent with neurobiological studies of temporal integration and with studies of memory deficits in individuals with prefrontal damage.     

Context reinstatement and memory for intrinsic versus extrinsic context: The role of item generation at encoding or retrieval

According to many theoretical accounts, reinstating study context at the time of test creates optimal circumstances for item retrieval. The role of context reinstatement was tested in reference to context memory in several experiments. On the encoding phase, participants were presented with words printed in two different font colors (intrinsic context) or two different sides of the computer screen (extrinsic context). At test, the context was reinstated or changed and participants were asked to recognize words and recollect their study context. Moreover, a read‐generate manipulation was introduced at encoding and retrieval, which was intended to influence the relative salience of item and context information. The results showed that context reinstatement had no effect on memory for extrinsic context but affected memory for intrinsic context when the item was generated at encoding and read at test. These results supported the hypothesis that context information is reconstructed at retrieval only when context was poorly encoded at study.     

Context-dependent recognition memory: the ICE theory

A solution to the problem of context-dependent recognition memory is presented in terms of the item, associated context, and ensemble (ICE) theory. It is argued that different types of context effects depend on how context information is encoded at both learning and retrieval. Matching associated context in memory and a retrieval cue produces increases in both hit and false alarm rates and may not be accompanied by a change in discrimination. Integrating item and context information in an ensemble and matching ensemble information in memory and a retrieval cue produces context-dependent discrimination. Empirical support for these predictions is presented.     

Reconstructive memory: A computer model

This study presents a process model of very long-term episodic memory. The process presented is a reconstructive process. The process involves application of three kinds of reconstructive strategies—component-to-context instantiation strategies, component-instantiation strategies, and context-to-context instantiation strategies. The first is used to direct search to appropriate conceptual categories in memory. The other two are used to direct search within the chosen conceptual category. A fourth type of strategy, called executive search strategies, guide search for concepts related to the one targeted for retrieval. A conceptual memory organization implied by human reconstructive memory is presented along with examples which motivate it. A basic retrieval algorithm is presented for traversing that stucture. Retrieval strategies arise from failures in that algorithm. The memory organization and retrieval processes are implemented in a computer program called CYRUS which stores events in the lives of former Secretaries of State Cyrus Vance and Edmund Muskie and answers questions posed in English concerning that information. Examples which motivate the process model are drawn from protocols of human memory search. Examples of CYRUS's behavior demonstrate the implemented process model. Conclusions are drawn concerning retrieval failures and the relationship of episodic and semantic memory.     

Working memory and focal attention

Measures of retrieval speed indicated that only a small subset of representations in working memory falls within the focus of attention. An n-back task, which required tracking an item 1, 2, or 3 back in a sequentially presented list, was used to examine the representation and retrieval of recent events and how control processes can be used to maintain an item in focal attention while concurrently processing new information. A speed-accuracy trade-off procedure was used to derive measures of the availability and the speed with which recent events can be accessed. Results converge with other time course studies in demonstrating that attention can be concurrently allocated only to a small number of memory representations, perhaps just 1 item. Measures of retrieval speed further demonstrate that order information is retrieved by a slow search process when an item is not maintained within focal attention.     

Bound context features are integrated at encoding

In the present research, we tested the predictions of different accounts of context binding in "remember" judgements. Context binding, defined as the stochastically dependent retrieval of two different context features, has previously been suggested to be due to mechanisms operating at retrieval either by cueing among context features (Meiser & Br?der, 2002) or by cueing between item and context features (Starns & Hicks, 2008). These accounts, however, do not make specific assumptions regarding the underlying memory representation supporting context binding. By contrast, here we propose that a binding process at encoding integrates item and context information into a coherent memory representation. Varying the presentation of the context features during encoding either with both context features presented simultaneously or with features spread over two encoding episodes, data from two experiments corroborate the notion that binding is produced at encoding. This result suggests that a binding process integrating the context features at encoding is necessary for stochastically dependent retrieval of context features.     

Picture memory: How the action schema affects retention

When an action scene is viewed, an action schema guides the formation of an episodic representation. Within episodic memory, items of high relevance to the theme of the action schema are represented in a prototypical form closely connected to the action theme. In contrast, items of low relevance are represented in detail but their representation is unconnected to that of the action. The action schema is used as a retrieval framework for both recalling and recognizing whether or not an item was depicted in a scene (i.e., item presence), but is not used for recognition of figurative detail (i.e., item appearance). Four experiments confirmed these hypotheses. Children, aged 7- and 9-years, and adults organized pictured scenes around themes from action schemata. The appearance of high relevant items was recognized poorly, while their presence was recalled well. Memory for the presence of high relevant items surpassed that for low relevant items even when recognition of item names was assessed. Conversely, the appearance of low relevant items was recognized accurately, but memory for their presence was difficult to retrieve.     

来源记忆提取的情境线索效应

探索当存在多维来源信息时,对一个维度的来源信息的再现是否会促进对另一个维度的来源记忆的提取,即出现情境线索效应。以汉字词语作为项目刺激,以背景颜色作为情境线索,通过两个实验分别考察对呈现位置和背景形状的提取是否会出现情境线索效应。结果发现：只在对背景形状的提取中出现了情境线索效应,并且线索负载越高,效应越小。该结果表明对来源记忆提取时,来源信息间的高可结合性是引发情境线索效应的重要因素。     

Autobiographical memory specificity and emotional disorder

The authors review research showing that when recalling autobiographical events, many emotionally disturbed patients summarize categories of events rather than retrieving a single episode. The mechanisms underlying such overgeneral memory are examined, with a focus on M. A. Conway and C. W. Pleydell-Pearce's (2000) hierarchical search model of personal event retrieval. An elaboration of this model is proposed to account for overgeneral memory, focusing on how memory search can be affected by (a) capture and rumination processes, when mnemonic information used in retrieval activates ruminative thinking; (b) functional avoidance, when episodic material threatens to cause affective disturbance; and (c) impairment in executive capacity and control that limits an individual's ability to remain focused on retrieval in the face of distraction.     

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。     

Who? What? When? Using a timeline technique to facilitate recall of a complex event

Accurately recalling a complex multi-actor incident presents witnesses with a cognitively demanding retrieval task. Given the important role played by temporal context in the retrieval process, the current research tests an innovative timeline technique to elicit information about multiple perpetrators and their actions. Adopting a standard mock witness paradigm, participants were required to provide an account of a witnessed event. In Experiment 1, the timeline technique facilitated the reporting of more correct details than a free recall, immediately and at a two-week retention interval, at no cost to accuracy. Accounts provided using the timeline technique included more correct information about perpetrator specific actions and fewer sequencing errors. Experiment 2 examined which mnemonic components of the timeline technique might account for these effects. The benefits of exploiting memory organization and reducing cognitive constraints on information flow are likely to underpin the apparent timeline advantage.     

Explicit memory for rejected distractors during visual search

Although memory for the identities of examined items is not used to guide visual search, identity memory may be acquired during visual search. In all experiments reported here, search was occasionally terminated and a memory test was presented for the identity of a previously examined item. Participants demonstrated memory for the locations of the examined items by avoiding revisits to these items and memory performance for the items’ identities was above chance but lower than expected based on performance in intentional memory tests. Memory performance improved when the foil was not from the search set, suggesting that explicit identity memory is not bound to memory for location. Providing context information during test improved memory for the most recently examined item. Memory for the identities of previously examined items was best when the most recently examined item was tested, contextual information was provided, and location memory was not required.     

Methodological issues in judgment and decision-making research: Concurrent verbal protocol validity and simultaneous traces of process

This paper examines two dimensions of concurrent verbal protocol validity. First, whether verbalization affects process and outcome (reactivity) was examined by comparing concurrent verbal protocol traces with those from a computer search process tracing method, the latter being a complete trace of information acquisition from experimental materials. Earlier findings that verbalization affects time were confirmed. However, verbalization did not affect amount and pattern of acquisition or accuracy of judgments. Second, whether concurrent verbal protocols are complete was examined by comparing concurrent verbal protocol and computer traces that were simultaneously obtained in a treatment in which subjects verbalized as they acquired information from the computer. The verbal traces less completely captured information acquisition behavior than computer search. This suggests that, although concurrent verbal protocols provide greater insight into decision behavior than computer search, the latter is a more reliable information-acquisition trace. Thus, if information acquisition is of primary interest and if computer search activities can be naturally integrated into performing the primary task, computer search is preferred to concurrent verbal protocols. However, if information use or retrieval from long-term memory is of primary interest, concurrent verbal protocols are preferred to computer search. Finally, this paper examined whether the simultaneous use of concurrent verbal protocols and computer search provides traces of information acquisition and use that are as complete as when each method is independently applied. Although computer search tended to limit subjects verbalizations of evaluative operators, this effect may be eliminated by practice on the computer prior to collecting data.     

Investigating the role of emotion during the search process in free recall

Typically, research has shown that emotional words are remembered better than neutral words; however, most studies have reported only the mean proportion of correctly recalled words. The present study looked at various dependent measures used by search models to determine whether emotion can influence the search process as well. The results from Experiment 2 showed that when emotionality was made salient, participants were able to utilize emotional associations, in addition to temporal associations, to cue retrieval of additional emotional words during subsequent sampling but relied mainly on temporal context when the emotional information was not made salient (Experiment 1). Additionally, both experiments showed that emotional words were more likely to be output earlier in the recall sequence, which would suggest that emotion also serves to boost relative strength during initial sampling. Overall, the results suggest that emotion contributes to enhanced memory dynamically by influencing the probability of sampling an item during the search process—specifically, by boosting relative strength and strengthening interitem associations.     

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.     

Contributions of the medial temporal lobe to declarative memory retrieval: manipulating the amount of contextual retrieval

We investigated how the hippocampus and its adjacent mediotemporal structures contribute to contextual and noncontextual declarative memory retrieval by manipulating the amount of contextual information across two levels of the same contextual dimension in a source memory task. A first analysis identified medial temporal lobe (MTL) substructures mediating either contextual or noncontextual retrieval. A linearly weighted analysis elucidated which MTL substructures show a gradually increasing neural activity, depending on the amount of contextual information retrieved. A hippocampal engagement was found during both levels of source memory but not during item memory retrieval. The anterior MTL including the perirhinal cortex was only engaged during item memory retrieval by an activity decrease. Only the posterior parahippocampal cortex showed an activation increasing with the amount of contextual information retrieved. If one assumes a roughly linear relationship between the blood-oxygenation level-dependent (BOLD) signal and the associated cognitive process, our results suggest that the posterior parahippocampal cortex is involved in contextual retrieval on the basis of memory strength while the hippocampus processes representations of item-context binding. The anterior MTL including perirhinal cortex seems to be particularly engaged in familiarity-based item recognition. If one assumes departure from linearity, however, our results can also be explained by one-dimensional modulation of memory strength.     

A context noise model of episodic word recognition

Item noise models of recognition assert that interference at retrieval is generated by the words from the study list. Context noise models of recognition assert that interference at retrieval is generated by the contexts in which the test word has appeared. The authors introduce the bind cue decide model of episodic memory, a Bayesian context noise model, and demonstrate how it can account for data from the item noise and dual-processing approaches to recognition memory. From the item noise perspective, list strength and list length effects, the mirror effect for word frequency and concreteness, and the effects of the similarity of other words in a list are considered. From the dual-processing perspective, process dissociation data on the effects of length, temporal separation of lists, strength, and diagnosticity of context are examined. The authors conclude that the context noise approach to recognition is a viable alternative to existing approaches.     

Retrieval experience in prospective memory: strategic monitoring and spontaneous retrieval

According to the multi-process model of prospective memory (McDaniel & Einstein, 2000), performance in a prospective memory task may be due to spontaneous retrieval processes or due to strategic monitoring. Spontaneous retrieval is typically accompanied by a pop up experience and strategic monitoring by a search experience. In this study we report two experiments with young adults in which we systematically investigated whether retrieval experience differed across experimental conditions. In Experiment 1 some prospective memory targets were preceded by associated primes. We expected that presenting primes would enhance performance by an automatic activation of the intention and hence lead to an increase in pop up experiences. In Experiment 2 half of the participants received instructions containing information about the specific context in which the prospective memory task would occur, whereas the other half of the participants received no such information. We expected that specific context instructions would enhance performance by legitimate anticipation of the prospective memory task and hence would lead to an increase in search experiences. The results confirmed these expectations. They indicate that the assessment of retrieval experience can provide valuable insights into the processes underlying prospective memory performance. They also suggest that retrieval experience can vary systematically across experimental situations as predicted by the multi-process model.