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The authors present a new model of free recall on the basis of M. W. Howard and M. J. Kahana's (2002a) temporal context model and M. Usher and J. L. McClelland's (2001) leaky-accumulator decision model. In this model, contextual drift gives rise to both short-term and long-term recency effects, and contextual retrieval gives rise to short-term and long-term contiguity effects. Recall decisions are controlled by a race between competitive leaky accumulators. The model captures the dynamics of immediate, delayed, and continual distractor free recall, demonstrating that dissociations between short- and long-term recency can naturally arise from a model in which an internal contextual state is used as the sole cue for retrieval across time scales. Keywords: recency, contiguity, free recall, context

In four experiments, we investigated background-color context effects in free recall. A total of 194 undergraduates studied words presented one by one against a background color, and oral free recall was tested after a 30-sec filled retention interval. A signal for recall was presented against a background color throughout the test. Recalled items were classified as same- and different-context items according to whether the background colors at study and test were the same or different. Significant context effects were found in Experiments 1 and 2, in which two background colors were randomly alternated word by word. No context effects were found in Experiments 3 and 4, in which a common background color was presented for all items (Experiment 3) or for a number of successive items (Experiment 4). The results indicate that a change in background colors is necessary and sufficient to produce context effects. Implications of the present findings are discussed.

Context variability can be defined as the number of preexperimental contexts in which a given concept appears. Following M. Steyvers and K. J. Malmberg's (2003) work, the authors have shown that concepts that are experienced in fewer preexperimental contexts generally are better remembered in episodic memory tasks than concepts that are experienced in a greater number of preexperimental contexts. The purpose of this article is to demonstrate that low context variability confers its memorial advantage because of stronger item-to-list context associations as compared with high context variability. Three experiments that use environmental context changes from study to test demonstrate that the low context variability advantage is eliminated when item-to-list context associations are not available because of environmental changes at test. In addition, the low context variability advantage is eliminated when inward processing at study prevents the formation of item-to-list context associations. Keywords: free recall, context variability, environmental context

Context variability refers to the number of preexperimental contexts that are associated with concepts. In four experiments, we investigated the basis for increased recognition memory for low context variability words. Low context variability was associated with greater recollection in the hit rates, and high context variability was associated with greater familiarity in the false alarms. Shortening the study time reduced recollection, but low context variability still influenced recollection in the hit rates. A modality change from study to test also reduced recollection but preserved recollective differences for low versus high context variability items. One interpretation of the results suggests that low context variability evokes more specific and, perhaps, idiosyncratic recollective associations during learning and that these associations support better recognition in the hit rates. By contrast, activating the larger number of associations for high context variability items may be mistaken for familiarity in the false alarm rates.

Episodic or context dependent memory is often studied as a function of the context cues in immediate retrieval of target information. Little research has been done on how the relationship of context cues to target retrieval changes over time, and none with older adult subjects. The current research investigated how the influence of context on accuracy of memory changes over time, and age-related differences in those influences. Using immediate, 2- and 7- day retention intervals, our results indicate that, while context initially supports the retrieval of information, assistance is temporary and fades before the memory for the target information. These changes in context effects were not different for younger and older adult groups.

During a retention test, a change in the nature of the incidental contextual information present during training can have a deleterious impact on response selection by not activating particular subsets of information in memory that help direct the retrieval process. The present experiment addressed whether a change in the incidental context also impacted the completion of processes associated with loading and searching the motor buffer during motor programming. A self-select paradigm was used to describe the planning and execution of one- and four-element sequences that consisted of short and long duration key-presses. During a test phase following training, changes in the incidental contextual information impeded the search of the motor buffer. However, loading specific timing information into the motor buffer was unaffected by shifts in contexts. These data support the contention that contextual information plays a fundamental role in a broad array of movement-planning operations that involve search and retrieval type activity.

Flashbulb memories (FBMs) are detailed recollections of the context in which people first heard about important events. The present study investigates three models of the formation and maintenance of FBM. Two models have previously been proposed in the literature (Brown & Kulik, 1977; Conway et al., 1994). A third model of FBM that integrates theories of FBM and recent developments in the field of emotions is proposed. The present study compares these three competing models by investigating the FBMs that Belgian citizens developed upon learning of the unexpected death of their king Baudouin. Structural equation modeling revealed that, as compared to the two previously proposed models, the third model, which takes into account emotional processes, better explains FBM.

Three experiments examined processing and recall differences associated with 2 different types of seductive details (i.e., highly interesting, but unimportant, text segments). Experiment I provided evidence of 2 different types of seductive details: those that are less interesting when read in isolation (context dependent) and those that are equally interesting in context or isolation (context independent). Experiment 2 found that context-dependent seductive details took longer to read and were recalled better than main ideas. Context-independent seductive details were recalled as well as context-dependent seductive details, but did not require more reading time than main ideas. Experiment 3 found that including seductive details did not interfere with overall story recall or recall of main ideas. Suggestions are made for future research that would enhance a theory of seductive details.

Two experiments were conducted to examine the role of contextual integration in memories of younger and older adults. Forty younger adults and 36 older adults were shown 36 pairs of pictures, one of which was the target and the other a context cue. Results for both experiments reveal that when sentences were generated that integrated the picture pair and when the pairs were already related to each other, recall was better. Regardless of which age group had generated the sentence, the participants' prediction about later recall and recall performance itself were the same.

Requiring readers to reorder randomly ordered sentences into a coherent text significantly enhances recall relative to that in a read-only control condition for non-folk-tale texts but not for folk tales (Einstein, McDaniel, Owen, & Cote, 1990). Experiments 1-3 showed that embedding components of folk tales (e.g., causal structure, conventional scripts, content related to background knowledge) in non-folk-tale texts did not render sentence unscrambling ineffective for increasing recall. In Experiments 4a-4c, a folk tale was presented either as a fairy tale or as part of a newspaper article. Significant sentence unscrambling effects (in free recall) were not obtained in either presentation format, which implies that a story superstructure (a story grammar) does not contribute to the absence of the sentence unscrambling effect. It is suggested that understanding why the sentence unscrambling effect is absent for folk tales may require considering the functional role that narrative plays in socioculturally situated cognition.

A series of studies addresses the possibility that tones disrupt serial recall of visually presented material in the same way as speech. A stream of changing tones is as disruptive of visual serial recall as 4 syllables (Experiments 1 and 2). Similar effects were also shown with a repeated syllable that changed only in pitch (Experiment 3). Just as for speech, the effect of tones is not at encoding but during storage of the serial lists (Experiments 4 and 5). The results suggest that speech and tones are equipotent in their capacity to disrupt short-term memory. A 'blackboard' model of working memory to account for the effects is outlined.

Recent experiments have implied that emotional arousal causes a narrowing of attention and, therefore, impoverished memory encoding. In contrast, other studies have found that emotional arousal enhances memory for all aspects of an event. We report two experiments investigating whether these differing results are due to the different retention intervals employed in past studies or to their different categorization schemes for the to-be-remembered material. Our results indicate a small role for retention interval in moderating emotion's effects on memory. However, emotion had markedly different impacts on different types of material: Emotion improved memory for gist and basic-level visual information and for plot-irrelevant details associated, both temporally and spatially, with the event's center. In contrast, emotion undermined memory for details not associated with the event's center. The mechanisms for emotion's effect are discussed.

Predictions of an automatic-imagery, strategic-imagery, and context-availability hypothesis of concreteness effects in free recall were examined. In each experiment, recall of abstract and concrete words controlled for rated context availability was compared with the typical situation in which context availability is confounded with imageability. In Experiment 1, a directed intentional-recall task produced concreteness effects in recall. Experiment 2 compared concreteness effects in recall following three orienting tasks: imagery rating, context-availability rating, and a directed intentional-memory task. Concreteness effects in the context-availability-controlled condition were found following the imagery-rating and the directed intentional-memory tasks, but not after the context-availability-rating task. In Experiment 3, subjects reported the strategies that they used to encode the list. Subjects reporting an imagery strategy showed concreteness effects for words controlled for rated context availability, but those not reporting it did not. These results support a strategic-imagery view of concreteness effects in free recall.

Undergraduate volunteers rated a series of words for pleasantness while hearing a particular background music. The subjects in Experiment 1 received, immediately or after a 48-h delay, an unexpected word-recall test in one of the following musical cue contexts: same cue (S), different cue (D), or no cue (N). For immediate recall, context dependency (S - D) was significant but same-cue facilitation (S - N) was not. No cue effects at all were found for delayed recall, and there was a significant interaction between cue and retention interval. A similar interaction was also found in Experiment 3, which was designed to rule out an alternative explanation with respect to distraction. When the different musical selection was changed specifically in either tempo or form (genre), only pieces having an altered tempo produced significantly lower immediate recall compared with the same pieces (Experiment 2). The results support a stimulus generalization view of music-dependent memory.

The current study investigated the effect of environmental context change between the study and test on the recall of action phrases that either were performed during encoding (subject-performed tasks, SPTs) or were verbally encoded (verbal tasks, VTs). Both SPTs and VTs showed the same magnitude of impaired recall when the study and test contexts mismatched. Furthermore, changing the context between the two study lists reduced cross-list intrusion errors compared to encoding the lists in the same context. Both SPTs and VTs benefited from studying the lists in different contexts as evidenced by reduced intrusions. Taken together, the results suggest that SPTs are integrated with their context because they suffered when context changed between the study and test, and they also benefited when they were performed in two environments versus the same environment.

This study investigated the differential effects of cuing in a number of contexts on recall and recognition at various retention intervals. Subjects were shown cue-target word pairs and were asked to recall the target words under three sets of cues, varying in relation to the original cue. All 80 subjects completed a recognition task following the final recall task. Results suggest type of cuing does not have differential effects on recall and recognition; both recall and recognition are hindered by cuing in a number of different contexts, and the ability to recall improves over time, cuing, and exposure to the list.

The presence of concreteness effects on recall of prose paragraphs was shown to depend on the language experience of the subjects, the nature of the task, and whether subjects were given both concrete and abstract passages. In Experiment 1, monolingual and bilingual subjects recalled both abstract and concrete English paragraphs following comprehension instructions. Although no overall difference in recall was found, monolinguals showed a large concreteness effect but bilinguals showed only a marginal one. In Experiment 2, the concreteness effect for monolinguals was eliminated by presenting only abstract or concrete paragraphs to agiven subject. In Experiment 3, after rating the imageability of individual sentences within abstract and concrete paragraphs, both language groups showed a large concreteness effect in recall. Concreteness effects can thus be obtained in recall of prose, tied not to differences in how abstract and concrete words are represented, but to how the prose is both encoded and retrieved. It is suggested that for bilinguals, the language of prose can act as a context specifier.

In immediate free recall, words recalled successively tend to come from nearby serial positions. M. J. Kahana (1996) documented this effect and showed that this tendency, which the authors refer to as the lag recency effect, is well described by a variant of the search of associative memory (SAM) model (J. G. W. Raaijmakers & R. M. Shiffrin, 1980, 1981). In 2 experiments, participants performed immediate, delayed, and continuous distractor free recall under conditions designed to minimize rehearsal. The lag recency effect, previously observed in immediate free recall, was also observed in delayed and continuous distractor free recall. Although two-store memory models, such as SAM, readily account for the end-of-list recency effect in immediate free recall, and its attenuation in delayed free recall, these models fail to account for the long-term recency effect. By means of analytic simulations, the authors show that both the end of list recency effect and the lag recency effect, across all distractor conditions, can be explained by a single-store model in which context, retrieved with each recalled item, serves as a cue for subsequent recalls.