Retrieval Of Items Research Articles

Distinguishing between high-confidence true and false memories: evidence from eye movements

ABSTRACT Objective: Memory confidence tends to be positively related to accuracy. However, false memory that fits well with the theme of an experience can also produce high-confidence responses. How to distinguish between high-confidence true and false recognition is unknown. The current study used eye movements to measure the retrieval processes of retrieval cues (i.e., item and theme) on recognition confidence and accuracy. Method: Participants (N = 30, Mage = 21.13 ± 2.06, 15 males) studied four visual thematic scenes, and after a filler task, took an item-theme recognition test in which their eye movements were recorded. Results: The gaze behaviour could distinguish between high-confidence true and false recognition. High-confidence false recognition was associated with longer fixation duration on item and theme, and more regression counts on theme as compared to high-confidence true recognition. Conclusion: High-confidence false recognition, compared to high-confidence true recognition, may have a weaker memory strength, such that more time-consuming and effortful retrieval-related monitoring processes were required before making a decision. The gaze behaviour based on both item and theme implied these processes. Thus, tracking eye movements during the identification may help evaluate whether a high-confidence recognition is true or false. KEY POINTS What is already known about this topic? False memories occur when people rely on the theme of an experience. The unexperienced item (e.g., “beach ball”) which is contextually associated with the theme (e.g., “beach scene”) of the experience can be recognized as “old”. Memory confidence tends to be positively related to accuracy. However, false memory that fits well with the theme of an experience can also produce high-confidence responses. Gaze behaviour recorded at retrieval can serve as indices of memory-related processing: previously viewed items had shorter fixation duration relative to high-interference novel items. What does this paper add? This study is the first to provide evidence suggesting that eye movements on either item cue or theme cue can differentiate between high-confidence true and false recognition. Compared to high-confidence true recognition, high-confidence false recognition was associated with longer fixation duration on item and theme. These results suggest that the time-consuming retrieval-related processes are based on both item and theme retrieval. High-confidence false recognition was related to more regression counts on theme than high-confidence true recognition, suggesting that inflated confidence of false recognition may be associated with more effortful retrieval-related monitoring processes.

Functional connectivity with the anterior and posterior hippocampus during spatial memory

Evidence of differential connectivity and activity patterns across the long-axis of the hippocampus has led to many hypotheses about functional specialization of the anterior and posterior hippocampus, including a hypothesis linking the anterior hippocampus to memory encoding and the posterior hippocampus to memory retrieval. The hippocampal encoding/retrieval and network (HERNET) model of memory predicts that encoding should engage the anterior hippocampus and the attention network, whereas retrieval should engage the posterior hippocampus and the default network. In a previous fMRI study that employed multivoxel pattern analysis, we found that the patterns of activity in the anterior hippocampus predicted the quadrant of spatial memory encoding. In the current fMRI study, we investigated whether the spatial memory encoding activity in the anterior hippocampus and retrieval activity in the posterior hippocampus had a higher degree of connectivity to the attention network or the default network. During the study phase, abstract shapes were presented in each quadrant of the visual field and participants were instructed to remember each shape's location while maintaining central fixation. During the test phase, the same shapes were presented in the center of the screen and participants identified the previous location of each shape. Generalized psychophysiological interaction analyses were conducted between the anatomically defined anterior and posterior hippocampus and the rest of the brain. This revealed preferential connectivity between the anterior hippocampus and regions of the attention network during encoding and between the posterior hippocampus and regions of the default network during retrieval. In addition, there were location-specific patterns of connectivity with the anterior hippocampus and posterior hippocampus during encoding and retrieval of right visual field items. These results suggest that the anterior and posterior hippocampus interact with regions of the attention network and default network during spatial memory encoding and retrieval, respectively, and support the HERNET model of memory.

The long-term consequences of retrieval demands during working memory.

Although it is well known that distraction impairs immediate retrieval of items maintained in working memory (WM; e.g., during complex span tasks), some evidence suggests that these items are more likely to be recalled from episodic memory (EM) compared with items that were studied without any distraction (e.g., during simple span tasks). One account for this delayed advantage of complex span over simple span, or the McCabe effect (McCabe, Journal of Memory and Language, 58[2], 480–494, 2008), is that complex span affords covert retrieval opportunities that facilitate later retrieval from EM by cumulatively reactivating each successively presented item after distraction. This explanation focuses on the processing that occurs during presentation and maintenance of the items, but no work to date has explored whether the differential demands of immediate retrieval between simple and complex span may explain the effect. Accordingly, these experiments examined the impact of immediate retrieval demands on the McCabe effect by comparing typical immediate serial-recall instructions (i.e., recalling the words in their exact order of presentation) to immediate free-recall (Experiments 1–2) and no-recall (Experiments 2 and 3) instructions. The results suggested that the nature of retrieval may constrain the McCabe effect in some situations (Experiments 1–2), but its demands do not drive the McCabe effect given that it was observed in both serial-recall and no-recall conditions (Experiment 3). Instead, activities such as covert retrieval during the processing phase may underlie the McCabe effect, thus further evidencing the importance of processing in WM for the long-term retention of information.Electronic supplementary materialThe online version of this article (10.3758/s13421-020-01079-5) contains supplementary material, which is available to authorized users.

WarpClothingOut: A Stepwise Framework for Clothes Translation From the Human Body to Tiled Images

With the increasing popularity of online shopping, searching for products with images for item retrieval has gradually become an effective approach. This trend is especially evident in the fashion industry. In common media, clothing items are usually worn on the human body. They can be straightforwardly segmented from the source media by utilizing detection or parsing algorithms. However, this may be deleterious to retrieval performance due to distortion, occlusion, and different backgrounds. In this article, a stepwise translation framework using generative adversarial network and thin plate spline is developed to transfer human body images to tiled clothing images, which can be directly used for clothing retrieval. Experimental results demonstrate the effectiveness of the resultant tiled images produced from our framework in comparison to other extant methods.

Patterns of single-neuron activity during associative recognition memory in the human medial temporal lobe

Electrophysiological activity in medial temporal lobe (MTL) structures is pivotal for declarative long-term memory. Single-neuron and microcircuit findings capitalizing on human microwire recordings from the medial temporal lobe are still fragmentary. In particular, it is an open question whether identical or different groups of neurons participate in different memory functions. Here, we investigated category-specific responses in the human MTL based on single-neuron recordings in presurgical epilepsy patients performing an associative long-term memory task. Additionally, auditory beat stimuli were presented during encoding and retrieval to modulate memory performance. We describe the proportion of neurons in amygdala, entorhinal cortex, hippocampus and parahippocampal cortex belonging to different response classes. These entail neurons coding stimulus-familiarity, neurons coding successful item memory, and neurons coding associated source memory, as well as the overlap between these classes. As major results we demonstrate that neurons responding to stimulus familiarity (old/new effect) can be identified in the MTL even when using previously known rather than entirely novel stimulus material (words). We observed a significant overlap between familiarity-related neurons and neurons coding item retrieval (remembered/forgotten effect). The largest fraction of familiarity-related neurons was found in the parahippocampal cortex, and a considerable fraction of all parahippocampal neurons was related to successful item retrieval. Neurons related to successful source retrieval were different from the neurons coding the associated information. Most importantly, there was no overlap between neurons coding item memory and those coding associated source memory strongly suggesting that these functions are facilitated by different sets of neurons.

Memorability of words in arbitrary verbal associations modulates memory retrieval in the anterior temporal lobe

Despite large individual differences in memory performance, people remember certain stimuli with overwhelming consistency. This phenomenon is referred to as the memorability of an individual item. It remains unknown, however, whether memorability also affects our ability to retrieve associations between items. Here, using a paired associates verbal memory task, we combine behavioural data, computational modelling, and direct recordings from the human brain to examine how memorability influences associative memory retrieval. We find that certain words are correctly retrieved across participants irrespective of the cues used to initiate memory retrieval. These words, which share greater semantic similarity with other words, are more readily available during retrieval and lead to more intrusions when retrieval fails. Successful retrieval of these memorable items, relative to less memorable ones, results in faster reinstatement of neural activity in the anterior temporal lobe. Collectively, our data reveal how the brain prioritizes certain information to facilitate memory retrieval.

Infant carrying method impacts caregiver posture and loading during gait and item retrieval

BackgroundHuman babies are carried by their caregivers during infancy, and the use of ergonomic aids to wear the baby on the body has recently grown in popularity. However, the effects of wearing or holding a baby in-arms on an individual’s mechanics during gait and a common object retrieval task are not fully understood. Research questionWhat are the differences in: 1) spatiotemporal, lower extremity kinematics, and ground reaction force variables during gait, and 2) technique, center of mass motion, and kinematics during an object retrieval task between holding and wearing an infant mannequin? MethodsIn this prospective biomechanics study, 10 healthy females performed over-ground walking and an object retrieval task in three conditions, holding: (1) nothing (unloaded), (2) an infant mannequin in-arms, and (3) an infant mannequin in a baby carrier. Mechanics were compared using repeated measures ANOVA. ResultsDuring gait, greater vertical ground reaction force and impulse and braking force was found during the in-arms and carrier conditions compared to unloaded. Significant but small (<5°) differences were found between conditions in lower extremity kinematics. Increased back extension was found during carrier and in-arms compared to unloaded. Step length was the only spatiotemporal parameter that differed between conditions. During object retrieval, most participants used a squatting technique to retrieve the object from the floor. They maintained a more upright posture, with less trunk flexion and anteroposterior movement of their center of mass, and also did not try to fold forward over their hips during the two loaded conditions. Lower extremity kinematics did not differ between unloaded and carrier, suggesting that babywearing may promote more similar lower extremity mechanics to not carrying anything. SignificanceHolding or wearing an infant provides a mechanical constraint that impacts the forces and kinematics, which has implications for caregivers’ pain and dysfunction.

Balancing exploration and exploitation: An image-based approach to item retrieval with enhanced diversity

We propose a machine learning approach based on relevance feedback to visually retrieve e-commerce items, represented by images, from huge catalogs. A threefold strategy is presented to deal with the exploration–exploitation dilemma: retrieve user-relevant items; retrieve items that do not comply with user learned preferences, to avoid convergence to local minima; and retrieve items from uncertainty regions, to improve the learning curve, all in a stochastic manner. To mitigate the cold start problem, we present a novel sampling method to improve the diversity of retrieved items that employs a combination of a multidimensional projection method with an adaptive spatial data structure. We performed quantitative and qualitative user experiments using an annotated catalog of clothing items. Results revealed that our approach can rapidly improve the retrieval of appropriate items in a few user iterations while providing higher diversity than other relevant and recent approaches.

Medial prefrontal decoupling from the default mode network benefits memory

In the last few years the involvement of the medial prefrontal cortex (mPFC) in memory processing has received increased attention. It has been shown to be centrally involved when we use prior knowledge (schemas) to improve learning of related material. With the mPFC also being one of the core hubs of the default mode network (DMN) and the DMN’s role in memory retrieval, we decided to investigate whether the mPFC in a schema paradigm acts independent of the DMN. We tested this with data from a cross-sectional developmental study with a schema paradigm. During retrieval of schema items, the mPFC decoupled from the DMN with the degree of decoupling predicting memory performance. This finding suggests that a demand specific reconfiguration of the DMN supports schema memory. Additionally, we found that in the control condition, which relied on episodic memory, activity in the parahippocampal gyrus was positively related to memory performance. We interpret these results as a demand specific network reconfiguration of the DMN: a decoupling of the mPFC to support schema memory and a decoupling of the parahippocampal gyrus facilitating episodic memory.

Product Quantized Collaborative Filtering

Because of strict response-time constraints, efficiency of top-k recommendation is crucial for real-world recommender systems. Locality sensitive hashing and index-based methods usually store both index data and item feature vectors in main memory, so they handle a limited number of items. Hashing-based recommendation methods enjoy low memory cost and fast retrieval of items, but suffer from large accuracy degradation. In this paper, we propose product Quantized Collaborative Filtering (pQCF) for better trade-off between efficiency and accuracy. pQCF decomposes a joint latent space of users and items into a Cartesian product of low-dimensional subspaces, and learns clustered representation within each subspace. A latent factor is then represented by a short code, which is composed of subspace cluster indexes. A user's preference for an item can be efficiently calculated via table lookup. We then develop block coordinate descent for efficient optimization and reveal the learning of latent factors is seamlessly integrated with quantization. We further investigate an asymmetric pQCF, dubbed as QCF, where user latent factors are not quantized and shared across different subspaces. The extensive experiments with 6 real-world datasets show that pQCF significantly outperforms the state-of-the-art hashing-based CF and QCF increases recommendation accuracy compared to pQCF.

Abstract 450: Rapid Cycle Deliberate Practice Improves Critical Item Retrieval From Crash Cart

Introduction: Unfamiliarity with crash cart contents contributes to decreased patient safety. There is no standardization of crash carts organization or contents. Initial moments of an emergency are critical and especially stressful. Responders familiar with the available equipment may be more efficient in retrieval and utilization of supplies. Methods: This study investigated the effects of Rapid Cycle Deliberate Practice (RCDP) as a training tool to increase familiarity with crash carts and contents, through a challenge of timed retrieval and assembly of critical items needed in response to in-hospital cardiac arrest (IHCA). Individuals were randomly assigned to one of four experimental groups to further identify efficient education methods. Hypothesis: RCDP predicted to improve retrieval performance and participant group assigned to hands-on discovery of the crash cart would show most improvement. Results: 75 interdisciplinary participants averaged total time for retrieval of 12 critical care items with completion of 4 corresponding tasks of 327 seconds decreased to 104 seconds from round 1 to 2. Secondly, average number of drawer pulls to retrieve items went from 14.8 to 10.5. The item most infrequently found in the 60 seconds allotted in round 1 was the intraosseous access kit (14/75, 18.67%). Connection of the defibrillator electrodes to the defibrillator device failed completion by 23 participants (30.67%) in the 60-second round 1. Retrieval of intraosseous access kit and connection of defibrillator electrodes was successful by all participants in round 2. Conclusions: Findings highlight the importance of training staff on available emergency equipment, with the expectation that increased familiarity and decreased response times will correlate to improved patient IHCA outcomes. Furthermore, findings indicate a need for standardization of crash cart organization across units and facilities.

Hippocampal theta codes for distances in semantic and temporal spaces

The medial temporal lobe (MTL) is known to support episodic memory and spatial navigation, raising the possibility that its true function is to form "cognitive maps" of any kind of information. Studies in humans and animals support the idea that the hippocampal theta rhythm (4 to 8 Hz) is key to this mapping function, as it has been repeatedly observed during spatial navigation tasks. If episodic memory and spatial navigation are 2 sides of the same coin, we hypothesized that theta oscillations might reflect relations between explicitly nonspatial items, such as words. We asked 189 neurosurgical patients to perform a verbal free-recall task, of which 96 had indwelling electrodes placed in the MTL. Subjects were instructed to remember short lists of sequentially presented nouns. We found that hippocampal theta power and connectivity during item retrieval coded for semantic distances between words, as measured using word2vec-derived subspaces. Additionally, hippocampal theta indexed temporal distances between words after filtering lists on recall performance, to ensure adequate dynamic range in time. Theta effects were noted only for semantic subspaces of 1 dimension, indicating a substantial compression of the possible semantic feature space. These results lend further support to our growing confidence that the MTL forms cognitive maps of arbitrary representational spaces, helping to reconcile longstanding differences between the spatial and episodic memory literatures.

Combining two separate series into a single ordering: Testing the local and global distinctiveness theories with absolute and relative judgments.

This study examined the differential effects of an absolute versus a relative judgment task on the retrieval of the border-position items after the combining of two separate serial lists. Under the absolute judgment condition (Experiment 1), the border-position items showed a local distinctiveness effect (faster judgment on these items than on the neighboring items), consistent with the prediction of the local distinctiveness theory of order memory, but not under the relative judgment condition (Experiment 2). The absence of the local distinctiveness effect under the relative judgment condition was consistent with the prediction of the global distinctiveness theory that a midseries item cannot be remembered better than its neighbors. The causes of the differential effects of the two judgment tasks were discussed.

Semantic processes in preferential decision making.

This article examines how semantic memory processes influence the items that are considered by decision makers in memory-based preferential choice. Experiments 1A through 1C ask participants to list the choice items that come to their minds while deliberating in a variety of everyday choice settings. These experiments use semantic space models to quantify the semantic relatedness between pairs of retrieved items and find that choice item retrieval displays robust semantic clustering effects, with retrieved items increasing the retrieval probabilities of related items. Semantic clustering can be disassociated from the effect of item desirability and can lead to inefficiencies such as the consideration and evaluation of undesirable items early on in the decision. Experiments 2A through 2C use a similar approach to study the effects of contextual cues on item retrieval and find that decision makers are biased toward retrieving choice items that are semantically related to the choice context. This effect is usually strongest early on in deliberation and weakens as additional items are retrieved. Overall, the results highlight the role of semantic memory processes in guiding the generation of memory-based choice sets, and illustrate the value of semantic space models for studying preferential decision making. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Selection for sentence generation in the context of severe anomia: A case series of left temporal patients

ABSTRACTIntroduction: Anomia is an impairment of naming: the retrieval of specific lexical items from the mental lexicon. Theoretically, whether anomia reflects a failure of selection at the preverbal “idea” level or at the subsequent linguistic formulation stage remains a topic of debate. We investigated the preverbal mechanism of idea selection for sentence generation, which requires the selection of a proposition from among competing alternatives during message formulation, in patients with severe anomia.Method: Patients with lesions to the left temporal lobe (N = 12), presenting with clinically defined anomia, and matched healthy controls (N = 24) completed sentence-level tasks that required the oral generation of a sentence or single word when presented with a word, a word pair, or a sentence. Selection demands were manipulated so that the stimuli activated many competing response options (low constraint) or one dominant or few response options (high constraint).Results: There was no effect of stimuli constraint in the patient group that differed from that in the healthy control group on any of the generation tasks, suggesting that idea-level selection is intact in the patient group.Conclusions: These findings have implications for theoretical models of spoken language production and for clinical treatments of anomia.

Study on batching and picking optimization of marine outfitting pallets

Outfitting pallet picking involves the retrieval of items from their storage sites in shipbuilding enterprises. A major issue in manual pallet picking operations is the transformation of outfitting pallets into picking batches (pallet batching). Considering the influence to the subsequent distribution and production processes, a mathematical model for the batching and picking problem of outfitting pallets is formulated with the objective of minimizing the total tardiness of all pallets. According to the characteristics of outfitting pallet picking operations, an Improved Genetic Algorithm (IGA) is proposed. A reversal operator is specially introduced to increase the local search ability of the standard genetic algorithm and speed up the evolution. Benchmarked against the solutions produced by the Earliest Due Date (EDD) rule, the performance of IGA is studied under different picking operations with different workloads and tightness of due dates. A series of numerical experiments are carried out to verify the researches. The results clearly show that IGA is competitive since it improves the solutions by 68.5%, on average, relative to the EDD.

Effects of acute psychosocial stress on the neural correlates of episodic encoding: Item versus associative memory.

Acute stress is known to modulate episodic memory, but little is known about the extent to, and the circumstances under, which stress affects encoding of item vs. inter-item associative information for words of different valences. Furthermore, the precise neuro-cognitive mechanisms underlying stress effects on episodic encoding in humans are largely unknown. To address these questions, in the present study we recorded EEG activity while male participants encoded neutral, negative and positive words, each paired with another word that was always neutral. Immediately before encoding, half of the participants experienced a psychosocial stressor, the Trier Social Stress Test, while the other half underwent a control procedure. Twenty-four hours later, participants completed separate item and associative recognition tests. Pre-learning stress enhanced item recognition accuracy for the positive, but not for the negative words. By contrast, there was no evidence for stress effects on associative recognition. The increase in item recognition was accompanied by a higher familiarity-, but not recollection-, based item retrieval of positive and neutral, but not negative words. Crucially, in the event-related potential (ERP) stress affected the amplitude of the frontal slow wave in general, and the frontal slow wave subsequent memory effect for positive words in specific, and the subsequent memory effect was correlated with cortisol levels after the stress manipulation. Our results suggest that positive words are encoded more elaboratively under stress, leading to a higher likelihood of subsequent item retrieval. An interaction of cortisol with frontal-lobe dependent control processes as well as a shift in attentional biases may contribute to this stress-induced modulation of episodic encoding.

Frequency-specific noninvasive modulation of memory retrieval and its relationship with hippocampal network connectivity.

Episodic memory is thought to rely on interactions of the hippocampus with other regions of the distributed hippocampal-cortical network (HCN) via interregional activity synchrony in the theta frequency band. We sought to causally test this hypothesis using network-targeted transcranial magnetic stimulation. Healthy human participants completed four experimental sessions, each involving a different stimulation pattern delivered to the same individualized parietal cortex location of the HCN for all sessions. There were three active stimulation conditions, including continuous theta-burst stimulation, intermittent theta-burst stimulation, and beta-frequency (20-Hz) repetitive stimulation, and one sham condition. Resting-state fMRI and episodic memory testing were used to assess the impact of stimulation on hippocampal fMRI connectivity related to retrieval success. We hypothesized that theta-burst stimulation conditions would most strongly influence hippocampal-HCN fMRI connectivity and retrieval, given the hypothesized relevance of theta-band activity for HCN memory function. Continuous theta-burst stimulation improved item retrieval success relative to sham and relative to beta-frequency stimulation, whereas intermittent theta-burst stimulation led to numerical but nonsignificant item retrieval improvement. Mean hippocampal fMRI connectivity did not vary for any stimulation conditions, whereas individual differences in retrieval improvements due to continuous theta-burst stimulation were associated with corresponding increases in fMRI connectivity between the hippocampus and other HCN locations. No such memory-related connectivity effects were identified for the other stimulation conditions, indicating that only continuous theta-burst stimulation affected memory-related hippocampal-HCN connectivity. Furthermore, these effects were specific to the targeted HCN, with no significant memory-related fMRI connectivity effects for two distinct control brain networks. These findings support a causal role for fMRI connectivity of the hippocampus with the HCN in episodic memory retrieval and indicate that contributions of this network to retrieval are particularly sensitive to continuous theta-burst noninvasive stimulation.

A Four-Stage Method for Optimizing and Standardizing a Crash Cart Configuration

OCCUPATIONAL APPLICATION An optimized crash cart configuration was developed through the use of human factors principles and by involving front-line users of crash carts in the design process from start to finish. The crash cart configuration was spread to four rural health care sites and received positive post-evaluation scores by clinical staff. The methodology used to develop the standardized crash cart, and the template for the configuration of the crash cart, can be adopted or adapted for use at any health care facility and can help in the mitigation of human error. Specifically, disorganized and/or inconsistent crash carts pose a patient safety risk due to the fact that retrieval of items may be delayed during critical situations. Implementing a tested, standardized crash cart configuration can increase the usability of the carts, which has significant patient safety implications during time-sensitive incidents such as code blue events.

The Effect of Word Retrieval Therapy in Primary Progressive Aphasia: A Single-Case Study

Background: Anomia is a common symptom that can be detrimental to the everyday communication of patients with primary progressive aphasia (PPA). Studies on the anomia treatment in PPA demonstrate that re-learning is possible, but the maintenance and generalization of improvements are limited. The treatment of word retrieval in PPA has typically centered on the retrieval of single lexical items. Little is known about the effects of word-finding treatments in discourse tasks on lexical retrieval. Objectives: The purpose of this study was to introduce a combined semantic/phonological cueing treatment in the context of narrative discourse as a novel method for the treatment of word retrieval difficulty in a PPA patient and compare its effects with the effect of cueing treatment in the context of single words. Methods: One individual with PPA (FK) participated in this single-subject interventional study. FK was a 56-year-old woman with a one-year history of word finding difficulties following Frontotemporal dementia. She received 16 sessions of naming treatment over an eight-week period. The participant completed three baselines prior to treatment. The treatment used a semantic and phonological cueing hierarchy (four weeks, two times a week), followed by a cueing in a story-retelling context (four weeks, two times a week). The main outcome was the naming ability assessment score administered 10 times in order to examine the effectiveness of the therapy through statistical analysis. Results: The participant showed a significant improvement in the word retrieval ability in all stimuli and each set separately related to the therapies phases (P < 0.001). Nevertheless, no significant differences were observed between the therapies (P = 0.26). Following the integrated therapy, FK showed a slightly significant improvement in untreated words. Conclusions: Generally, without considering the type of therapy during this study, in spite of the progressive nature of the disease, word retrieval ability of the patient improved via both treatment programs. Furthermore, the generalization of untreated items and maintenance of treated items also were occurred to some extents. However, there was no evidence of integrated discourse context in cueing hierarchy protocol to make it elaborated and cause a greater effect in people with PPA. As the first known study to trial this issue in the context of PPA, its findings may warrant further investigations.