Fragment and schema models for recall

Two general conceptualizations of recall may be distinguished. One holds that recall is sub-served by memory traces in which representations of different aspects of external events are linked directly to each other. The other holds that these representations are connected via a mediating concept. Formalizations of these views are provided by two theories examined by Ross and Bower (1981a): the “fragment” and “schema” models, respectively. Ross and Bower found that patterns of cued recall of clusters of words with a common theme were predicted well by the schema model, but not by the fragment model. Two experiments reported here show that the reverse is true if the clusters of words are selected randomly. Ross and Bower also considered separately a third theory, the “horizontal” model. However, the horizontal model is shown here to be a constrained form of the fragment model. Another constrained form of the fragment model, termed the “link” model, is introduced and is shown to provide an account of encoding as well as of retrieval that, although it is outstandingly parsimonious, is also approximately accurate. Finally, it is shown that the memory structures characterized by the fragment model may be interpreted as either graphs or digraphs: that is, networks with either bidirectional or unidirectional connections between nodes.     

Effects of encoding instructions and retrieval cuing on recall in Korsakoff patients

The relationship between the depth of encoding a word and its subsequent recall, either cued or noncued, was investigated in this study. In Experiment 1, Korsakoff subjects and alcoholic controls were shown a categorized word list under one of three different encoding instructions: (1) nonsemantic, that is, detecting the presence or absence of the letter “e” in each word, (2)semantic, that is, assigning words to their correct taxonomic category, and (3) no encoding instructions. Semantic encoding instructions resulted in higher recall for both diagnostic groups than the other instructions. In Experiment 2, subjects were again assigned to one of the three encoding instructions as in Experiment 1, but all groups received cues (category labels) at the time of recall. Cuing increased recall for all but the group receiving instructions to encode nonsemantically. Experiment 3 was a replication of the previous experiments. The results indicated that Korsakoff subjects were capable of encoding semantically without specific instructions to do so but were impaired in the ability to generate retrieval cues at the time of recall.     

The generation effect and the modeling of associations in memory

The search of associative memory (SAM) model of Gillund and Shiffrin (1984) was applied to data of two experiments that examined the generation effect (Slamecka & Graf, 1978). Subjects studied a list of related word pairs, in which they either read both words in the pair or generated the righthand response term using the left-hand stimulus term plus the response word fragment as generation cues. Experiment 1 manipulated encoding condition within subjects and used an incidental learning procedure. Experiment 2 manipulated encoding condition between subjects and used an intentional learning procedure. Memory was tested with recognition, cued recall, and free recall. A higher order association model gave a better and more parsimonious fit to the results than did an item-level association model. The relationship between various versions of SAM and current accounts of the generation effect are discussed, particularly the two-factor theory of Hirshman and Bjork (1988).     

Encoding specificity in the alcoholic Korsakoff patient

A previous attempt to improve amnesic Korsakoff patients' retention of individual words resulted in only moderate improvement and, then, only under restricted conditions. It appeared that this occurred because the patients “forget” the instructed analysis of the word as well as the word itself. Consequently, the two experiments reported here sought to provide feature (Experiment 1) or associated (Experiment 2) cues at both input and output. In this manner relatively good performance was obtained, but only when semantic cues were “strongly” associated to the target words. Implications for an encoding specificity interpretation are drawn from these results.     

The properties of retrieval cues constrain the picture superiority effect

In three experiments, we examined why pictures are remembered better than words on explicit memory tests like recall and recognition, whereas words produce more priming than pictures on some implicit tests, such as word-fragment and word-stem completion (e.g., completing -l-ph-nt or ele----- as elephant). One possibility is that pictures are always more accessible than words if subjects are given explicit retrieval instructions. An alternative possibility is that the properties of the retrieval cues themselves constrain the retrieval processes engaged; word fragments might induce data-driven (perceptually based) retrieval, which favors words regardless of the retrieval instructions. Experiment 1 demonstrated that words were remembered better than pictures on both the word-fragment and word-stem completion tasks under both implicit and explicit retrieval conditions. In Experiment 2, pictures were recalled better than words with semantically related extralist cues. In Experiment 3, when semantic cues were combined with word fragments, pictures and words were recalled equally well under explicit retrieval conditions, but words were superior to pictures under implicit instructions. Thus, the inherently data-limited properties of fragmented words limit their use in accessing conceptual codes. Overall, the results indicate that retrieval operations are largely determined by properties of the retrieval cues under both implicit and explicit retrieval conditions.     

Symbolic control of visual attention: Semantic constraints on the spatial distribution of attention

Humans routinely use spatial language to control the spatial distribution of attention. In so doing, spatial information may be communicated from one individual to another across opposing frames of reference, which in turn can lead to inconsistent mappings between symbols and directions (or locations). These inconsistencies may have important implications for the symbolic control of attention because they can be translated into differences in cue validity, a manipulation that is known to influence the focus of attention. This differential validity hypothesis was tested in Experiment 1 by comparing spatial word cues that were predicted to have high learned spatial validity (“above/below”) and low learned spatial validity (“left/right”). Consistent with this prediction, when two measures of selective attention were used, the results indicated that attention was less focused in response to “left/right” cues than in response to “above/below” cues, even when the actual validity of each of the cues was equal. In addition, Experiment 2 predicted that spatial words such as “left/right” would have lower spatial validity than would other directional symbols that specify direction along the horizontal axis, such as “←/→” cues. The results were also consistent with this hypothesis. Altogether, the present findings demonstrate important semantic-based constraints on the spatial distribution of attention.     

情绪效价的记忆增强效应:存储或提取优势?

情绪效价和情绪唤醒是描述情绪的两个维度。情绪增强记忆效应表明情绪唤醒事件的记忆往往优于非情绪唤醒事件的记忆,但关于积极情绪记忆和消极情绪记忆哪个在记忆中处于优势仍存在争论。实验以情绪词对和中性词对为实验材料。实验一探讨积极情绪词语或消极情绪词语的记忆优势; 实验二探讨积极情绪环境或消极情绪环境中中性词语的记忆优势。在两种实验条件下,积极情绪下的自由回忆都优于消极情绪下的自由回忆; 多项加工树的存储—提取模型使用实验自由回忆和线索回忆的结果将记忆的存储和提取优势分离开来,结果表明:积极情绪事件记忆优势发生在存储阶段,而积极情绪环境记忆优势发生在存储和提取阶段; 积极情绪事件记忆偏向支持“刺激后编码增强假设”,积极情绪环境记忆偏向支持“唤醒—偏向竞争假设”。     

Hypermnesia: The role of multiple retrieval cues

We demonstrate that encoding multiple cues enhances hypermnesia. College students were presented with 36 (Experiment 1) or 60 (Experiments 2 and 3) sets of words and were asked to encode the sets under single- or multiple-cue conditions. In the single-cue conditions, each set consisted of a cue and a target. In the multiple-cue conditions, each set consisted of three cues and a target. Following the presentation of the word sets, the participants received either three cued recall tests (Experiments 1 and 2) or three free recall tests (Experiment 3). With this manipulation, we observed greater hypermnesia in the multiple-cue conditions than in the single-cue conditions. Furthermore, the greater hypermnesic recall resulted from increased reminiscence rather than reduced intertest forgetting. The present findings support the hypothesis that the availability of multiple retrieval cues plays an important role in hypermnesia.     

Part-set cuing of false memories

Part-set cuing inhibition describes the common finding that re-presenting items from a word list can reduce subjects’ overall recall performance for studied items. Do part-set cuing effects occur for false memories as well? In the present experiments, subjects studied lists of words drawn from Roediger and McDermott (1995). After studying each list, subjects completed math problems and then recalled the list items either with or without accompanying list cues. In Experiment 1, the recall cues consisted of items drawn randomly from the original list. In Experiment 2, an additional type of cued recall task was added in which the even numbered list items were used as cues. Taken together, these experiments demonstrate robust part-set cuing effects for critical nonpresented items. In addition, they show that whereas recall of critical words is reduced by the presence of cues at test, retrieval cues do not affect critical words and studied words in exactly the same manner.     

The more,the better?: Number of decisions as a determinant of memorability

Three experiments tested alternative explanations to the Johnson-Laird, Gibbs, and deMowbray (1978) proposal that the number of decisions made about a word is a major determinant of its memorability. The alternatives considered were increased processing time, retrieval aids, and the number of positive decisions. In Experiment 1, subjects made a speeded classification about each word for a category defined by three properties. Though items with more target properties were processed longer and better remembered, within a property level processing time was not associated with better memory. In Experiment 2, subjects received three properties, but different groups responded “Yes” to words with all three properties, words with any of the three properties, or whether words had each of the properties. As predicted by the number-of-decisions hypothesis, but not by the other hypotheses, with an increasing number of target properties, recall generally increased in the ALL group, decreased in the ANY group, and remained constant in the EACH group. In Experiment 3, this recall pattern was replicated with a different set of two target properties. The number-of-decisions notion is contrasted to the elaboration principle, and a simple model is proposed. It is concluded that the number of decisions is a useful technique for investigating within-level encoding differences     

Serial position-dependent false memory effects*

ABSTRACT

Evidence for false recognition within seconds of encoding suggests that semantic-associative influences are not restricted to long-term memory, consistent with unitary memory accounts but contrary to dual store models. The present study sought further relevant evidence using a modified free recall converging associates task where participants studied 12-item lists composed of 3 semantically distinct quartets (sublists) related to a separate, non-presented theme word (i.e., words 1–4/theme1, 5–8/theme2, and 9–12/theme3). This list construction permits assessment of false recall errors from each sublist, and, particularly, the primacy and recency sublists that have been linked to long- and short-term memory stores. Experiment 1 tested immediate free recall for items. Associative false memories were evident from all sublists, however, significantly less so from the recent sublist, which also showed the highest levels of veridical memory. By inserting a brief (3?s) distractor prior to recall, Experiment 2 selectively reduced veridical memory and increased false memory for the recent sublist while leaving the primacy sublist unaffected. These recall results converge with prior evidence indicating the immediacy of false recognition, and can be understood within a unitary framework where the differential availability of verbatim features and gist-based cues affect memory for primacy and recency sublists.     

Taboo words: The effect of emotion on memory for peripheral information

In three experiments, we examined memory for peripheral information that occurred in the same context as emotion-inducing information. In the first two experiments, participants studied either a sentence (Experiment 1) or a pair of words (Experiments 2A—2C) containing a neutral peripheral word, as well as a neutral, negative-valence, or taboo word, to induce an emotional response. At retrieval, the participants were asked to recall the neutral peripheral word from a sentence fragment or emotion-inducing word cue. In Experiment 3, we presented word pairs at encoding and tested memory with associative recognition. In all three experiments, memory for peripheral words was enhanced when it was encoded in the presence of emotionally arousing taboo words but not when it was encoded in the presence of words that were only negative in valence. These data are consistent with priority-binding theory (MacKay et al., 2004) and inconsistent with the attention-narrowing hypothesis (Easterbrook, 1959), as well as with object-based binding theory (Mather, 2007).     

The missing link? Testing a schema account of unitization

Unitization refers to the creation of a new unit from previously distinct items. The concept of unitization has been used to explain how novel pairings between items can be remembered without requiring recollection, by virtue of new, item-like representations that enable familiarity-based retrieval. We tested an alternative account of unitization – a schema account – which suggests that associations between items can be rapidly assimilated into a schema. We used a common operationalization of “unitization” as the difference between two unrelated words being linked by a definition, relative to two words being linked by a sentence, during an initial study phase. During the following relearning phase, a studied word was re-paired with a new word, either related or unrelated to the original associate from study. In a final test phase, memory for the relearned associations was tested. We hypothesized that, if unitized representations act like schemas, then we would observe some generalization to related words, such that memory would be better in the definition than sentence condition for related words, but not for unrelated words. Contrary to the schema hypothesis, evidence favored the null hypothesis of no difference between definition and sentence conditions for related words (Experiment 1), even when each cue was associated with multiple associates, indicating that the associations can be generalized (Experiment 2), or when the schematic information was explicitly re-activated during Relearning (Experiment 3). These results suggest that unitized associations do not generalize to accommodate new information, and therefore provide evidence against the schema account.     

The impact of attention load on the use of statistical information and coarticulation as speech segmentation cues

In two artificial language learning experiments, we investigated the impact of attention load on segmenting speech through two sublexical cues: transitional probabilities (TPs) and coarticulation. In Experiment 1, we observed that coarticulation processing was resilient to high attention load, whereas TP computation was penalized in a graded manner. In Experiment 2, we showed that encouraging participants to actively search for “word” candidates enhanced overall performance but was not sufficient to preclude the impairment of statistically driven segmentation by attention load. As long as attentional resources were depleted, independently of their intention to find these “words,” participants segmented only TP words with the highest TPs, not TP words with lower TPs. Attention load thus has a graded and differential impact on the relative weighting of the cues in speech segmentation, even when only sublexical cues are available in the signal.     

The tip-of-the-tongue phenomenon: Blocking or partial activation?

Tip-of-the-tongue states may represent the momentary unavailability of an otherwise accessible word or the weak activation of an otherwise inaccessible word. In three experiments designed to address these alternative views, subjects attempted to retrieve rare target words from their definitions. The definitions were followed by cues that were related to the targets in sound, by cues that were related in meaning, and by cues that were not related to the targets. Experiment 1 found that compared with unrelated cues, related cue words that were presented immediately after target definitions helped rather than hindered lexical retrieval, and that sound cues were more effective retrieval aids than meaning cues. Experiment 2 replicated these results when cues were presented after an initial target-retrieval attempt. These findings reverse a previous one (Jones, 1989) that was reproduced in Experiment 3 and shown to stem from a small group of unusually difficult target definitions.     

Two-channel visual memory

Ss attempted immediate recall of word and color attributes of series of three “Stroop” words (Experiments I and 2) or three colored number words (Experiments 3 and 4), presented either at 2 words/sec or I word/2 sec. They were instructed to give either channel-by-channel recall, grouping words and colors together, or temporal recall, in which the two attributes of each item were to be reported together. In Experiments I and 3, in which words were to be reported before colors, channel-by-channel recall was rather better than temporal recall, especially at the fast rate. In Experiments 2 and 4, the colors were to be reported before the words, and channel-by-channel recall tended to be worse than temporal recall. In all four experiments serial position data suggested that the channel-by-channel strategy was to attend to one attribute (either words or colors) during presentation and hold the other in preattentive storage. By contrast, when instructed to give temporal report, Ss apparently alternated attention between attributes during presentation.     

Role of gravitational cues in the haptic perception of orientation

The haptic perception of vertical, horizontal, +45°-oblique, and +135°-oblique orientations was studied in adults. The purpose was to establish whether the gravitational cues provided by the scanning arm—hand system were involved in the haptic oblique effect (lower performances in oblique orientations than in vertical—horizontal ones) and more generally in the haptic coding of orientation. The magnitude of these cues was manipulated by changing gravity constraints, and their variability was manipulated by changing the planes in which the task was performed (horizontal, frontal, and sagittal). In Experiment 1, only the horizontal plane was tested, either with the forearm resting on the disk supporting the rod (“supported forearm” condition) or with the forearm unsupported in the air. In the latter case, antigravitational forces were elicited during scanning. The oblique effect was present in the “unsupported” condition and was absent in the “supported” condition. In Experiment 2, the three planes were tested, either in a “natural” or in a “lightened forearm” condition in which the gravitational cues were reduced by lightening the subject’s forearm. The magnitude of the oblique effect was lower in the “lightened” condition than in the “natural” one, and there was no plane effect. In Experiment 3, the subject’s forearm was loaded with either a 500- or a 1,000-g bracelet, or it was not loaded. The oblique effect was the same in the three conditions, and the plane effect (lower performances in the horizontal plane than in the frontal and sagittal ones) was present only when the forearm was loaded. Taken together, these results suggested that gravitational cues may play a role in haptic coding of orientation, although the effects of decreasing or increasing these cues are not symmetrical.     

Phonological priming effects on word retrieval and tip-of-the-tongue experiences in young and older adults

In a repetition priming paradigm, young and older participants read aloud prime words that sometimes shared phonological components with a target word that answered a general knowledge question. In Experiment 1, prior processing of phonologically related words decreased tip-of-the-tongue states (TOTs) and increased correct responses to subsequent questions. In Experiment 2, the priming task occurred only when the participant could not answer the question. Processing phonologically related words increased correct recall, but only when the participant was in a TOT state. Phonological priming effects were age invariant, although older adults produced relatively more TOTs. Results support the transmission deficit model that the weak connections among phonological representations that cause TOTs are strengthened by production of phonologically related words. There was no evidence that phonologically related words block TOT targets.     

Retrieval in cued recall

Three experiments examined retrieval in a cued recall paradigm by manipulating the pattern of output cues. In the first two experiments, subjects were paced through recall of a categorized list by recalling one word at a time in response to a category name as a retrieval cue. The pattern of these output cues exerted a strong influence on performance. Subjects recalled considerably more when the cues were blocked by category than when required to recall successive words from different categories. This output effect increased over trials, and was interpreted in terms of a model in which subjects develop a retrieval strategy that can be interfered with by the circumstances of output. The last experiment contrasted structural and strategy models in a hierarchical recall paradigm. Subjects were given a set of postinput recall cues that either made evident the hierarchical structure of the input list or contained the same cue words but with no hierarchical information. Information about the hierarchical structure improved performance even when provided only during recall. The data were discuss in terms of recent models of recall, and a compromise was suggested.