Organization In Recall Research Articles

Temporal organization of narrative recall is present but attenuated in adults with hippocampal amnesia.

Studies of the impact of brain injury on memory processes often focus on the quantity and episodic richness of those recollections. Here, we argue that the organization of one's recollections offers critical insights into the impact of brain injury on functional memory. It is well-established in studies of word list memory that free recall of unrelated words exhibits a clear temporal organization. This temporal contiguity effect refers to the fact that the order in which word lists are recalled reflects the original presentation order. Little is known, however, about the organization of recall for semantically rich materials, nor how recall organization is impacted by hippocampal damage and memory impairment. The present research is the first study, to our knowledge, of temporal organization in semantically rich narratives in three groups: (1) Adults with bilateral hippocampal damage and severe declarative memory impairment, (2) adults with bilateral ventromedial prefrontal cortex (vmPFC) damage and no memory impairment, and (3) demographically matched non-brain-injured comparison participants. We find that although the narrative recall of adults with bilateral hippocampal damage reflected the temporal order in which those narratives were experienced above chance levels, their temporal contiguity effect was significantly attenuated relative to comparison groups. In contrast, individuals with vmPFC damage did not differ from non-brain-injured comparison participants in temporal contiguity. This pattern of group differences yields insights into the cognitive and neural systems that support the use of temporal organization in recall. These data provide evidence that the retrieval of temporal context in narrative recall is hippocampal-dependent, whereas damage to the vmPFC does not impair the temporal organization of narrative recall. This evidence of limited but demonstrable organization of memory in participants with hippocampal damage and amnesia speaks to the power of narrative structures in supporting meaningfully organized recall despite memory impairment.

The modulation and elimination of temporal organization in free recall.

Experiences occur in a continual succession, and the temporal structure of those experiences is often preserved in memory. The temporal contiguity effect of free recall reveals the temporal structure of memory: when a particular item is remembered, the next response is likely to come from a nearby list position. This effect is remarkably robust, appearing across a wide variety of methodological variations of the task. The temporal contiguity effect is also central to retrieved-context models, which propose temporal organization arises from the interaction of a temporal context representation with the contents of memory. Across six experiments, we demonstrate methodological manipulations that dramatically modulate and even eliminate temporal organization in free recall. We find that temporal organization is strongly modulated and in some cases potentially eliminated by strong semantic structure, the presence of retrieval practice, and a long list length. Other factors such as orienting task, paired-associate item structure, and retention interval duration have more subtle effects on temporal organization. In an accompanying set of simulations, we show that the modulation and elimination of the temporal organization follows lawful patterns predicted by the context maintenance and retrieval (CMR) retrieved-context model. We also find cases where CMR does not specifically predict the modulation of temporal organization, and in these cases our analysis suggests how the theory might be developed to account for these effects. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Contextual familiarity rescues the cost of switching.

Changes in context influence the way we form and structure memories. Yet, little is known about how qualitatively different types of context switches shape memory organization. The current experiments characterize how different features of context change influence the structure and organization of free recall. Participants completed a context switching paradigm in which we manipulated the rate of switches and prior experience with the contexts participants were switching between (repeated vs. novel). We measured free-recall performance and determined the extent to which participants organized items by the order in which they were encoded or the type of context with which they were originally presented. Across two experiments, we found and replicated that rapidly switching to novel, but not repeated contexts, impaired memory recall performance and biased memory towards a greater reliance on temporal information. Critically, we observed that these differences in performance may be due to distinctions in how participants organize their recalls when rapidly switching contexts. Results indicated that participants were less likely to only cluster their responses by the same context when the contexts were repeating at a high rate, as compared to when the contexts were novel. Overall, our findings support a model in which contextual familiarity rescues the costs associated with rapidly switching to new tasks or contexts.

Contextual reinstatement affects semantic organization.

The Context Dependency Effect is the well-established finding in which memory performance is enhanced under conditions in which the encoding and retrieval contexts overlap (i.e., Same-Context) and diminished when the overlap between encoding and retrieval contexts is low (i.e., Different-Context). Despite much research on context-dependent memory, most prior work examined only mean performance levels. The current experiment examined the influence of context change, manipulated by using three different pieces of background music, on semantic organization during free recall. Recall driven by semantic organization captures an important, ecologically valid aspect of memory retrieval: because narratives of real-life events are typically comprised of semantically related concepts (e.g., "sea," "bathing suit," and "sand" when recalling a trip to the beach), their recall is likely driven by semantic organization. Participants in the current study were tested in the same or different context as the material was learned. The results showed that although the mean number of correctly recalled items was numerically greater in the Same-Context condition compared to the Different-Context condition, the Context Dependency Effect was not significant. In contrast, however, semantic clustering-an established measure of semantic organization-was greater in the Different-Context condition compared to the Same-Context condition. Together, these results suggest that when contextual cues at recall are relatively meager, participants instead use semantic information as cues to guide memory retrieval. In line with previous findings, temporal organization, patterns of errors, and serial position analyses showed no differences between the two context conditions. The present experiment provides novel evidence on how external context change affects recall organization.

Optimal policies for free recall.

There is rich structure in the order in which studied material is recalled in a free recall task (Howard & Kahana, 2002a). Extensive effort has been directed at understanding the processes and representations that give rise to this structure; however, it remains unclear why certain types of recall organization might be favored in the first place. We provide a rational analysis of the free recall task, deriving the optimal policy for recalling items under the internal representations and processes described by the context maintenance and retrieval (CMR) model of memory search (Polyn et al., 2009a). Our model, which we call rational-CMR, shows that the optimal policy for free recall is to start from the beginning of the list and then sequentially recall forwards, providing a rational account of the primacy and forward asymmetry effects typically observed in free recall. In addition, when recall is not initiated from the beginning of list, it is optimal during recall transitions to minimize the amount of forward asymmetry. Predictions from the rational model are confirmed in human behavioral data: Top-performing human participants demonstrate a stronger tendency to initiate recall from the beginning of the list and carry forward recalls, and the amount of forward asymmetry in participants depends on whether they start recall from the beginning or end of the list. We discuss the resemblance of optimal behavior in free recall to participants' behavior when applying mnemonic techniques such as the method of loci. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Attentional fluctuations and the temporal organization of memory

Event boundaries and temporal context shape the organization of episodic memories. We hypothesized that attentional fluctuations during encoding serve as “events” that affect temporal context representations and recall organization. Individuals encoded trial-unique objects during a modified sustained attention task. Memory was tested with free recall. Response time variability during the encoding tasks was used to characterize “in the zone” and “out of the zone” attentional states. We predicted that: 1) “in the zone”, vs. “out of the zone”, attentional states should be more conducive to maintaining temporal context representations that can cue temporally organized recall; and 2) temporally distant “in the zone” states may enable more recall “leaps” across intervening items. We replicated several important findings in the sustained attention and memory fields, including more online errors during “out of the zone” vs. “in the zone” attentional states and recall that was temporally structured. Yet, across four studies, we found no evidence for either of our main hypotheses. Recall was robustly temporally organized, and there was no difference in recall organization for items encoded “in the zone” vs. “out of the zone”. We conclude that temporal context serves as a strong scaffold for episodic memory, one that can support organized recall even for items encoded during relatively poor attentional states. We also highlight the numerous challenges in striking a balance between sustained attention tasks (long blocks of a repetitive task) and memory recall tasks (short lists of unique items) and describe strategies for researchers interested in uniting these two fields.

Children’s memory “in the wild”: examining the temporal organization of free recall from a week-long camp at a local zoo

Free-recall paradigms have greatly influenced our understanding of memory. The majority of this research involves laboratory-based events (e.g., word lists) that are studied and tested within minutes. This literature shows that adults recall events in a temporally organized way, with successive responses often coming from neighboring list positions (i.e., temporal clustering) and with enhanced memorability of items from the end of a list (i.e., recency). Temporal clustering effects are so robust that temporal organization is described as a fundamental memory property. Yet relatively little is known about the development of this temporal structure across childhood, and even less about children’s memory search for real-world events occurring over an extended period. In the present work, children (N = 144; 3 age groups: 4–5-year-olds, 6–7-year-olds, 8–10-year-olds) took part in a 5-day summer camp at a local zoo. The camp involved various dynamic events, including daily animal exhibit visits. On day 5, children were asked to recall all the animals they visited. We found that overall recall performance, in terms of number of animals recalled, improved steadily across childhood. Temporal organization and recency effects showed different developmental patterns. Temporal clustering was evident in the response sequences for all age groups and became progressively stronger across childhood. In contrast, the recency advantage, when characterized as a proportion of total responses, was stable across age groups. Thus, recall dynamics in early childhood parallel that seen in adulthood, with continued development of temporal organization across middle to late childhood.

Value restructures the organization of free recall

A large body of research illustrates the prioritization of goal-relevant information in memory; however, it is unclear how reward-related memories are organized. Using a rewarded free recall paradigm, we investigated how reward motivation structures the organization of memory around temporal and higher-order contexts. To better understand these processes, we simulated our findings using a reward-modulated variant of the Context Maintenance and Retrieval Model (CMR; Polyn et al., 2009). In the first study, we found that reward did not influence temporal clustering, but instead shifted the organization of memory based on reward category. Further, we showed that a reward-modulated learning rate and source features of CMR most accurately depict reward's enhancement on memory and clustering by value. In a second study, we showed that reward-memory effects can exist in both extended periods of sustained motivation and frequent changes in motivation, by showing equivalent reward effects using mixed- and pure-list motivation manipulations. However, we showed that a reward-modulated learning rate in isolation can support reward's enhancement of memory in pure-list contexts. Overall, we conclude that reward-related memories are adaptively organized by higher-order value information, and contextual binding to value contexts may only be necessary when rewards are intermittent versus sustained.

Effects of combining retrieval practice and tDCS over long-term memory: A randomized controlled trial

The ability to retain new information is important in daily life. In particular, two techniques have shown promise for improving long-term retention: retrieval practice (RP), which consists of actively retrieving information from long-term memory to make it more accessible in the future; and transcranial direct current stimulation (tDCS), which consists of non-invasive brain stimulation that modulates cognitive processes by increasing and decreasing neuronal excitability. Previous studies have implicated the left dorsolateral prefrontal cortex (l-dlPFC) in memory encoding and memory organization. We examined whether RP associated with a single 20-min tDCS session over the l-dlPFC could improve long-term memory retention. Participants (N = 119) repeatedly studied a list of related words either via RP or via restudy, while undergoing either anodal or sham stimulation. Participants returned 2 days later for a free-recall test. Results showed that the RP group outperformed the restudy group in all measures, regardless of stimulation type. Also, recall organization was higher in the RP group than in the restudy group. The data support previous findings and indicate that RP may enhance performance by improving the organization of the to-be-remembered list items.

Linking Detail to Temporal Structure in Naturalistic-Event Recall

Decades of memory research demonstrate the importance of temporal organization in recall dynamics, using laboratory stimuli (i.e., word lists) at seconds- to minutes-long delays. Little is known, however, about such organization in recall of richer and more remote real-world experiences, in which the focus is usually on memory content without reference to event order. Here, 119 younger and older adults freely recalled extended real-world experiences, for which the encoding sequence was controlled, after 2 days or 1 week. We paired analytical tools from the list-learning and autobiographical memory literatures to measure spontaneous contextual dynamics and details in these recall narratives. Recall dynamics were organized by temporal context (contiguity and forward asymmetry), and organization was reduced in older age, despite similar serial position effects and recall initiation across age groups. Across participants, organization was positively associated with richness of episodic detail, providing evidence for a link between reexperiencing past events and reinstating their spatiotemporal context.

Free recall dynamics in value-directed remembering

An emerging literature on value-directed remembering has shown that people are able to encode and remember information that is more important. Researchers operationalize importance by differentially assigning value to the memoranda that participants are asked to encode and remember. In the present investigation, a slightly altered value-directed-remembering paradigm was used to investigate how value modifies the dynamics of memory organization and search in free recall. In Experiment 1, free recall dynamics were compared between a control and a value condition. In Experiment 2, we manipulated the order of presentation of the values by adding an ascending and a descending condition where values were presented congruently or incongruently with the evolution of temporal context. Experiments 3 and 4 paralleled Experiments 1 and 2 respectively, with the addition of overt rehearsal and an unexpected memory test for the numbers/values. Overall, the results indicated that value-directed encoding has an influence on measures of delayed free recall encoding, organization, and search processes.

The role of episodic context in retrieval practice effects.

The episodic context account of retrieval-based learning proposes that retrieval enhances subsequent retention because people must think back to and reinstate a prior learning context. Three experiments directly tested this central assumption of the context account. Subjects studied word lists and then either restudied the words under intentional learning conditions or made list discrimination judgments by indicating which list each word had occurred in originally. Subjects in both conditions experienced all items for the same amount of time, but subjects in the list discrimination condition were required to retrieve details about the original episodic context in which the words had occurred. Making initial list discrimination judgments consistently enhanced subsequent free recall relative to restudying the words. Analyses of recall organization and retrieval strategies on the final test showed that retrieval practice enhanced temporal organization during final recall. Semantic encoding tasks also enhanced retention relative to restudying but did so by promoting semantic organization and semantically based retrieval strategies during final recall. The results support the episodic context account of retrieval-based learning. (PsycINFO Database Record

Lingering representations of stimuli influence recall organization

Several prominent theories posit that information about recent experiences lingers in the brain and organizes memories for current experiences, by forming a temporal context that is linked to those memories at encoding. According to these theories, if the thoughts preceding an experience X resemble the thoughts preceding an experience Y, then X and Y should show an elevated probability of being recalled together. We tested this prediction by using multi-voxel pattern analysis (MVPA) of fMRI data to measure neural evidence for lingering processing of preceding stimuli. As predicted, memories encoded with similar lingering thoughts about the category of preceding stimuli were more likely to be recalled together. Our results demonstrate that the “fading embers” of previous stimuli help to organize recall, confirming a key prediction of computational models of episodic memory.

A predictive framework for evaluating models of semantic organization in free recall.

Research in free recall has demonstrated that semantic associations reliably influence the organization of search through episodic memory. However, the specific structure of these associations and the mechanisms by which they influence memory search remain unclear. We introduce a likelihood-based model-comparison technique, which embeds a model of semantic structure within the context maintenance and retrieval (CMR) model of human memory search. Within this framework, model variants are evaluated in terms of their ability to predict the specific sequence in which items are recalled. We compare three models of semantic structure, latent semantic analysis (LSA), global vectors (GloVe), and word association spaces (WAS), and find that models using WAS have the greatest predictive power. Furthermore, we find evidence that semantic and temporal organization is driven by distinct item and context cues, rather than a single context cue. This finding provides important constraint for theories of memory search.

Verbal Episodic Memory Impairment in Schizophrenia: A Comparison with Frontal Lobe Lesion Patients

Schizophrenia (SCZ)-related verbal memory impairment is hypothesized to be mediated, in part, by frontal lobe (FTL) dysfunction. However, little research has contrasted the performance of SCZ patients with that of patients exhibiting circumscribed frontal lesions. The current study compared verbal episodic memory in patients with SCZ and focal FTL lesions (left frontal, LF; right frontal, RF; and bi-frontal, BF) on a four-trial list learning task consisting of three lists of varying semantic organizational structure. Each dependent variable was examined at two levels: scores collapsed across all four trials and learning scores (i.e., trial 4–trial 1). Performance deficits were observed in each patient group across most dependent measures at both levels. Regarding patient group differences, SCZ patients outperformed LF/BF patients (i.e., either learning scores or scores collapsed across trial) on free recall, primacy, primary memory, secondary memory, and subjective organization, whereas they only outperformed RF patients on the semantically blocked list on recency and primary memory. Collectively, these results indicate that the pattern of memory performance is largely similar between patients with SCZ and those with RF lesions. These data support tentative arguments that verbal episodic memory deficits in SCZ may be mediated by frontal dysfunction in the right hemisphere.

Category-Specific Neural Oscillations Predict Recall Organization During Memory Search

Retrieved-context models of human memory propose that as material is studied, retrieval cues are constructed that allow one to target particular aspects of past experience. We examined the neural predictions of these models by using electrocorticographic/depth recordings and scalp electroencephalography (EEG) to characterize category-specific oscillatory activity, while participants studied and recalled items from distinct, neurally discriminable categories. During study, these category-specific patterns predict whether a studied item will be recalled. In the scalp EEG experiment, category-specific activity during study also predicts whether a given item will be recalled adjacent to other same-category items, consistent with the proposal that a category-specific retrieval cue is used to guide memory search. Retrieved-context models suggest that integrative neural circuitry is involved in the construction and maintenance of the retrieval cue. Consistent with this hypothesis, we observe category-specific patterns that rise in strength as multiple same-category items are studied sequentially, and find that individual differences in this category-specific neural integration during study predict the degree to which a participant will use category information to organize memory search. Finally, we track the deployment of this retrieval cue during memory search: Category-specific patterns are stronger when participants organize their responses according to the category of the studied material.

Differential characteristics of the aging process and the vascular cognitive impairment in the organization of memory retrieval

Early identification of cognitive impairment in patients with chronic cerebral vascular disorders can allow for evaluating the time course of the disease up to the phase of conversion to dementia. The specific indicators of pathological cognitive decline should be identifiable vs. the concurrent age-associated changes in memory which accompany the aging process.We propose a method which evaluates memory dysfunctions in vascular cognitive impairment (VCI) as distinct from age-associated memory changes. This method is based on a serial learning task of concrete frequent words and it consists in controlling the effects of age and cerebral pathology on various characteristics of immediate recall, including serial effect and productivity.Ninety participants underwent a between group examination: younger adults vs. older adults vs. VCI patients who were outpatients with a positive history for chronic cerebral vascular disorder, positive neuroimaging examination, a Hachinski ischemic score≥5 and a mild to moderate cognitive impairment.VCI patients show a reduced efficiency of retrieval and recall organization while, age-associated cognitive changes consist of a modification of the serial position effects. In particular, VCI patients, as distinct from same-age normal cases, can perform an only partial utilization of the inherent structure of the memory task with a very limited efficiency of relearning which is not sufficiently supported by the facilitating factors due to task repetition.

Study repetition and divided attention: Effects of encoding manipulations on collaborative inhibition in group recall

Two experiments tested the effects of encoding manipulations on group recall and on the magnitude of collaborative inhibition. Collaborative inhibition refers to the phenomenon where by a collaborative group recalls less than do the same number of individuals who work alone and then have their nonredundant responses pooled. Participants studied categorized word lists once or three times (Experiment 1) or under conditions of full versus divided attention (Experiment 2). Study repetition both improved retrieval organization in recall and attenuated collaborative inhibition, and divided attention encoding both reduced retrieval organization in recall and eliminated collaborative inhibition. These experiments are the first to focus on encoding variables and to show that collaborative inhibition can vary as a function of encoding manipulations.

Task context and organization in free recall

Prior work on organization in free recall has focused on the ways in which semantic and temporal information determine the order in which material is retrieved from memory. Tulving's theory of ecphory suggests that these organizational effects arise from the interaction of a retrieval cue with the contents of memory. Using the continual-distraction free-recall paradigm [Bjork, R. A., & Whitten, W. B. (1974). Recency-sensitive retrieval processes in long-term free recall. Cognitive Psychology, 6, 173-189] to minimize retrieval during the study period, we show that encoding task context can organize recall, suggesting that task-related information is part of the retrieval cue. We interpret these results in terms of the Context Maintenance and Retrieval model (CMR; [Polyn, S. M., Norman, K. A., & Kahana, M. J. (2009). A context maintenance and retrieval model of organizational processes in free recall. Psychological Review, 116 (1), 129-156]), in which an internal contextual representation, containing semantic, temporal, and source-related information, serves as the retrieval cue and organizes the retrieval of information from memory. We discuss these results in terms of the guided activation theory [Miller, E. K., & Cohen, J. D. (2001). An integrative theory of prefrontal cortex function. Annual Review of Neuroscience, 24, 167-202] of the role of prefrontal cortex in task performance, as well as the rich neuropsychological literature implicating prefrontal cortex in memory search (e.g., Schacter (1987). Memory, amnesia, and frontal lobe dysfunction. Psychobiology, 15, 21-36).

Associations Between Performance on the Rey-Osterrieth Complex Figure and Regional Brain Volumes in Children with and without Velocardiofacial Syndrome

Ninety-two children with velocardiofacial syndrome (VCFS), a genetic disorder caused by a microdeletion of chromosome 22q11.2 and an age, race, and gender-ratio comparable sample of 59 control participants were included in the project. Participants received an MRI as well as a comprehensive neuropsychological battery; the primary outcome measure in the current report is the Rey-Osterrieth Complex Figure (ROCF). Children with VCFS performed less well on the ROCF and have lower whole brain volume compared to controls. After controlling for whole brain volume differences, children with VCFS have bilaterally less parietal lobe gray and white matter yet more frontal lobe white matter. Brain–behavior relationships include: (a) for both groups, parietal volumes (both gray and white matter) predicted ROCF Copy Organization performance and frontal volumes (both gray and white matter) predicted ROCF Copy Accuracy performance; (b) for controls, frontal white matter also predicted ROCF Copy Organization performance; (c) ROCF Recall Organization performance was best predicted by frontal gray matter volume only in our controls; ROCF Recall Accuracy performance was best predicted by frontal gray matter volume in both groups; and (d) in children with VCFS, performance on the ROCF-Copy Structural Elements Accuracy scale was predicted by right hemisphere white matter volume. Our hypotheses were also retested using IQ-matched and whole brain volume-matched subsamples. Identical results were obtained in these analyses. Assumptions about the organization of and the localization of the brain structures that subserve specific cognitive functions in the typically developing brain may not apply in the abnormally developing brain.