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Introduction: Schizophrenia is characterized by a loss of network features between cognition and reward sub-circuits (notably involving the mesolimbic system), and this loss may explain deficits in learning and cognition. Learning in schizophrenia has typically been studied with tasks that include reward related contingencies, but recent theoretical models have argued that a loss of network features should be seen even when learning without reward. We tested this model using a learning paradigm that required participants to learn without reward or feedback. We used a novel method for capturing higher order network features, to demonstrate that the mesolimbic system is heavily implicated in the loss of network features in schizophrenia, even when learning without reward. Methods: fMRI data (Siemens Verio 3T) were acquired in a group of schizophrenia patients and controls (n=78; 46 SCZ, 18 = Age = 50) while participants engaged in associative learning without reward-related contingencies. The task was divided into task-active conditions for encoding (of associations) and cued-retrieval (where the cue was to be used to retrieve the associated memoranda). No feedback was provided during retrieval. From the fMRI time series data, network features were defined as follows: First, for each condition of the task, we estimated 2nd order undirected functional connectivity for each participant (uFC, based on zero lag correlations between all pairs of regions). These conventional 2nd order features represent the task/condition evoked synchronization of activity between pairs of brain regions. Next, in each of the patient and control groups, the statistical relationship between all possible pairs of 2nd order features were computed. These higher order features represent the consistency between all possible pairs of 2nd order features in that group and embed within them the contributions of individual regions to such group structure. Results: From the identified inter-group differences (SCZ - HC) in higher order features, we quantified the respective contributions of individual brain regions. Two principal effects emerged: 1) SCZ were characterized by a massive loss of higher order features during multiple task conditions (encoding and retrieval of associations). 2) Nodes in the mesolimbic system were over-represented in the loss of higher order features in SCZ, and notably so during retrieval. Discussion: Our analytical goals were linked to a recent circuit-based integrative model which argued that synergy between learning and reward circuits is lost in schizophrenia. Themodel's notable prediction was that such a losswould be observed evenwhen patients learnedwithout reward. Our results provide substantial support for these predictions where we observed a loss of network features between the brain's sub-circuits for a) learning (including the hippocampus and prefrontal cortex) and b) reward processing (specifically constituents of the mesolimbic system that included the ventral tegmental area and the nucleus accumbens. Our findings motivate a renewed appraisal of the relationship between reward and cognition in schizophrenia and we discuss their relevance for putative behavioral interventions. [ABSTRACT FROM AUTHOR]

Introduction: Schizophrenia is characterized by a loss of network features between cognition and reward sub-circuits (notably involving the mesolimbic system), and this loss may explain deficits in learning and cognition. Learning in schizophrenia has typically been studied with tasks that include reward related contingencies, but recent theoretical models have argued that a loss of network features should be seen even when learning without reward. We tested this model using a learning paradigm that required participants to learn without reward or feedback. We used a novel method for capturing higher order network features, to demonstrate that the mesolimbic system is heavily implicated in the loss of network features in schizophrenia, even when learning without reward. Methods: fMRI data (Siemens Verio 3T) were acquired in a group of schizophrenia patients and controls (n=78; 46 SCZ, 18 ≤ Age ≤ 50) while participants engaged in associative learning without reward-related contingencies. The task was divided into task-active conditions for encoding (of associations) and cued-retrieval (where the cue was to be used to retrieve the associated memoranda). No feedback was provided during retrieval. From the fMRI time series data, network features were defined as follows: First, for each condition of the task, we estimated 2nd order undirected functional connectivity for each participant (uFC, based on zero lag correlations between all pairs of regions). These conventional 2nd order features represent the task/condition evoked synchronization of activity between pairs of brain regions. Next, in each of the patient and control groups, the statistical relationship between all possible pairs of 2nd order features were computed. These higher order features represent the consistency between all possible pairs of 2nd order features in that group and embed within them the contributions of individual regions to such group structure. Results: From the identified inter-group differences (SCZ ≠ HC) in higher order features, we quantified the respective contributions of individual brain regions. Two principal effects emerged: 1) SCZ were characterized by a massive loss of higher order features during multiple task conditions (encoding and retrieval of associations). 2) Nodes in the mesolimbic system were over-represented in the loss of higher order features in SCZ, and notably so during retrieval. Discussion: Our analytical goals were linked to a recent circuit-based integrative model which argued that synergy between learning and reward circuits is lost in schizophrenia. The model's notable prediction was that such a loss would be observed even when patients learned without reward. Our results provide substantial support for these predictions where we observed a loss of network features between the brain's sub-circuits for a) learning (including the hippocampus and prefrontal cortex) and b) reward processing (specifically constituents of the mesolimbic system that included the ventral tegmental area and the nucleus accumbens. Our findings motivate a renewed appraisal of the relationship between reward and cognition in schizophrenia and we discuss their relevance for putative behavioral interventions. [ABSTRACT FROM AUTHOR]

The abundance of distractors in the world poses a major challenge to our brain's limited processing capacity, but little is known about how selective attention modulates stimulus representations in the brain to reduce interference and support durable target memory. Here, we collected functional magnetic resonance imaging (fMRI) data in a selective attention task in which target and distractor pictures of different visual categories were simultaneously presented. Participants were asked to selectively process the target according to the effective cue, either before the encoding period (i.e., perceptual attention) or the maintenance period (i.e., reflective attention). On the next day, participants were asked to perform a memory recognition task in the scanner in which the targets, distractors, and novel items were presented in a pseudorandom order. Behavioral results showed that perceptual attention was better at enhancing target memory and reducing distractor memory than reflective attention, although the overall memory capacity (memory for both target and distractor) was comparable. Using multiple-voxel pattern analysis of the neural data, we found more robust target representation and weaker distractor representation in working memory for perceptual attention than for reflective attention. Interestingly, perceptual attention partially shifted the regions involved in maintaining the target representation from the visual cortex to the parietal cortex. Furthermore, the targets and distractors simultaneously presented in the perceptual attention condition showed reduced pattern similarity in the parietal cortex during retrieval compared to items not presented together. This neural pattern repulsion positively correlated with individuals' recognition of both targets and distractors. These results emphasize the critical role of selective attention in transforming memory representations to reduce interference and improve long-term memory performance. Selective attention helps humans to overcome our brain's limited processing capacity. This neuroimaging study shows how selective attention transforms memory representations to reduce interference and support long-term memory. [ABSTRACT FROM AUTHOR]

Purpose: Traumatic brain injury (TBI) is associated with a range of cognitive-communicative deficits that interfere with everyday communication and social interaction. Considerable effort has been directed at characterizing the nature and scope of cognitive-communication disorders in TBI, yet the underlying mechanisms of impairment are largely unspecified. The present research examines sensitivity to a common communicative cue, disfluency, and its impact on memory for spoken language in TBI. Method: Fifty-three participants with moderate–severe TBI and 53 non-injured comparison participants listened to a series of sentences, some of which contained disfluencies. A subsequent memory test probed memory for critical words in the sentences. Results: Participants with TBI successfully remembered the spoken words (b = 1.57, p < .0001) at a similar level to non-injured comparison participants. Critically, participants with TBI also exhibited better recognition memory for words preceded by disfluency compared to words from fluent sentences (b = 0.57, p = .02). Conclusions: These findings advance mechanistic accounts of cognitive-communication disorder by revealing that, when isolated for experimental study, individuals with moderate–severe TBI are sensitive to attentional orienting cues in speech and exhibit enhanced recognition of individual words preceded by disfluency. These results suggest that some aspects of cognitive-communication disorders may not emerge from an inability to perceive and use individual communication cues, but rather from disruptions in managing (i.e., attending, weighting, integrating) multiple cognitive, communicative, and social cues in complex and dynamic interactions. This hypothesis warrants further investigation. [ABSTRACT FROM AUTHOR]

The hippocampus and parahippocampal gyrus have been implicated as part of a tinnitus network by a number of studies. These structures are usually considered in the context of a "limbic system," a concept typically invoked to explain the emotional response to tinnitus. Despite this common framing, it is not apparent from current literature that this is necessarily the main functional role of these structures in persistent tinnitus. Here, we highlight a different role that encompasses their most commonly implicated functional position within the brain—that is, as a memory system. We consider tinnitus as an auditory object that is held in memory, which may be made persistent by associated activity from the hippocampus and parahippocampal gyrus. Evidence from animal and human studies implicating these structures in tinnitus is reviewed and used as an anchor for this hypothesis. We highlight the potential for the hippocampus/parahippocampal gyrus to facilitate maintenance of the memory of the tinnitus percept via communication with auditory cortex, rather than (or in addition to) mediating emotional responses to this percept. [ABSTRACT FROM AUTHOR]

Purpose: Lexical processing impairments such as delayed and reduced activation of lexical-semantic information have been linked to syntactic processing disruptions and sentence comprehension deficits in individuals with aphasia (IWAs). Lexical-level deficits can also preclude successful lexical encoding during sentence processing and amplify the processing costs of similarity-based interference during syntactic retrieval. We investigate whether two manipulations to engage attention and pre-activate semantic features of a target (to-be-retrieved) noun will (a) boost lexical activation during initial lexical encoding and (b) facilitate syntactic dependency linking through improved resolution of interference in IWAs and neurologically unimpaired age-matched controls (AMCs). Method: Eye-tracking-while-listening with a visual world paradigm was used to investigate whether semantic and attentional manipulations modulated initial lexical processing and downstream syntactic retrieval of the direct-object noun in object-relative sentences. Results: In the attention and semantic manipulations, the AMC group showed no changes in initial lexical access levels; however, gaze patterns revealed clear facilitations in dependency linking and interference resolution. In the IWA group, the attentional cue increased and maintained activation of N1 with modest facilitations in dependency linking. In the semantic condition, IWA results showed a greater degree of facilitation during dependency linking. Conclusions: The results suggest that attention and semantic activation are parameters that may be manipulated to strengthen encoding of lexical representations to facilitate retrieval (i.e., dependency linking) and mitigate similaritybased interference. In IWAs, these manipulations may help to reduce lexical processing deficits that can preclude successful encoding. [ABSTRACT FROM AUTHOR]

People better remember experiences when they orient to meaning over surface-level perceptual features. Such an orientation-related memory boost has been associated with engagement of both hippocampus (HPC) and neocortex during encoding. However, less is known about the neural mechanisms by which a cognitive orientation toward meaning might also promote memory errors, with one open question being whether the HPC—a region traditionally implicated in precise memory formation—also contributes to behavioral imprecision. We used fMRI to characterize encoding-phase signatures as people oriented toward the meaning (story) versus perceptual style (artist) of storybook-style illustrations and then linked them to subsequent true and false memories. We found that story and artist orientation tasks were each associated with both unique univariate profiles and consistent neural states defined using multivoxel patterns. Linking these neural signatures to behavior, we found that greater medial pFC activation and alignment of neural patterns to the story (but not artist) state was related to subsequent memory success on a trial-by-trial basis. Moreover, among successfully remembered experiences, greater anterior HPC engagement at encoding was associated with a higher likelihood of related false recognitions, consistent with the encoding of broad traces in this region. Interestingly, these effects did not reliably vary by cued orientation. These results suggest that, irrespective of the cued encoding orientation, neocortical and hippocampal mechanisms associated with orienting to meaning (story) over perceptual (artist) features may support memory, with the formation of generalizable memories being a specialty of anterior HPC. [ABSTRACT FROM AUTHOR]

Stress can powerfully influence episodic memory, often enhancing memory encoding for emotionally salient information. These stress-induced memory enhancements stand at odds with demonstrations that stress and the stress-related hormone cortisol can negatively affect the hippocampus, a brain region important for episodic memory encoding. To resolve this apparent conflict and determine whether and how the hippocampus supports memory encoding under cortisol, we combined behavioral assays of associative memory, high-resolution fMRI, and pharmacological manipulation of cortisol in a within-participant, double-blinded procedure (in both sexes). Behaviorally, hydrocortisone promoted the encoding of subjectively arousing, positive associative memories. Neurally, hydrocortisone led to enhanced functional connectivity between hippocampal subregions, which predicted subsequent memory enhancements for emotional associations. Cortisol also modified the relationship between hippocampal representations and associative memory: whereas hippocampal signatures of distinctiveness predicted memory under placebo, relative integration predicted memory under cortisol. Together, these data provide novel evidence that the human hippocampus contains the necessary machinery to support emotional associative memory enhancements under cortisol. [ABSTRACT FROM AUTHOR]

Visual input arrives in a continuous stream, but we often experience the world as a sequence of discrete events — and the boundaries between events have important consequences for our mental lives. Perhaps the best example of this is that memory not only declines as a function of elapsed time, but is also impaired when crossing an event boundary — as when walking through a doorway. (This impairment may be adaptive, as when one "flushes" a cache in a computer program when completing a function.) But when exactly does this impairment occur? Existing work has not asked this question: based on a reasonable assumption that forgetting occurs when we cross event boundaries, memory has only been tested after this point. Here we demonstrate that even visual cues to an impending event boundary (that one has not yet crossed) suffice to trigger forgetting. Subjects viewed an immersive animation that simulated walking through a room. Before their walk, they saw a list of pseudo-words, and immediately after their walk, their recognition memory was tested. During their walk, some subjects passed through a doorway, while others did not (equating time and distance traveled). Memory was impaired (relative to the "no doorway" condition) not only when they passed through the doorway, but also when they were tested just before they would have crossed the doorway. Additional controls confirmed that this was due to the anticipation of event boundaries (rather than differential surprise or visual complexity). Visual processing may proactively "flush" memory to some degree in preparation for future events. [ABSTRACT FROM AUTHOR]

Non‐conscious processing of human memory has traditionally been difficult to objectively measure and thus understand. A prior study on a group of hippocampal amnesia (N = 3) patients and healthy controls (N = 6) used a novel procedure for capturing neural correlates of implicit memory using event‐related potentials (ERPs): old and new items were equated for varying levels of memory awareness, with ERP differences observed from 400 to 800 ms in bilateral parietal regions that were hippocampal‐dependent. The current investigation sought to address the limitations of that study by increasing the sample of healthy subjects (N = 54), applying new controls for construct validity, and developing an improved, open‐source tool for automated analysis of the procedure used for equating levels of memory awareness. Results faithfully reproduced prior ERP findings of parietal effects that a series of systematic control analyses validated were not contributed to nor contaminated by explicit memory. Implicit memory effects extended from 600 to 1000 ms, localized to right parietal sites. These ERP effects were found to be behaviorally relevant and specific in predicting implicit memory response times, and were topographically dissociable from other traditional ERP measures of implicit memory (miss vs. correct rejections) that instead occurred in left parietal regions. Results suggest first that equating for reported awareness of memory strength is a valid, powerful new method for revealing neural correlates of non‐conscious human memory, and second, behavioral correlations suggest that these implicit effects reflect a pure form of priming, whereas misses represent fluency leading to the subjective experience of familiarity. Psychology wrestles with objectively measuring implicit memory. We used ERPs to assess a novel measure of implicit memory, created an automated analysis, validated it, and made it open source. ERPs dissociated two kinds of non‐conscious memory, one linked to fluency and later familiarity, and another linked to pure implicit activity. [ABSTRACT FROM AUTHOR]

The unequal variance signal detection (UVSD) model of recognition memory assumes that the variance of old item memory strength (σo) is typically greater than that of new items. It has been suggested that this old item variance effect can be explained by the encoding variability hypothesis. However, Spanton and Berry (2020) failed to find evidence for this account, suggesting that σo may simply scale with mean memory strength (d) in the UVSD model. Experiments 1 and 2 examined the effects of encoding variability and strength scaling on old item variance by creating conditions in which mean memory strength and variability in item characteristics was either low or high in 2 × 2 factorial designs. In Experiment 1, overall strength determined estimates of σo, with no effect of item characteristic variability. The same effect of overall strength was found in Experiment 2; there was also a significant effect of item characteristic variability, although this manipulation also had some effect on d and was therefore partially confounded. Experiment 3 similarly found a simultaneous increase in old item variance and memory strength in a design using mixed item characteristic variability conditions in a single-study/test block. We conclude that old item variance increases with mean memory strength in the UVSD model, with uncertainty about the effects of encoding variability, and that future explanations of the old item variance effect should bear this in mind. [ABSTRACT FROM AUTHOR]

Target detection has been found to enhance memory for concurrently presented stimuli under dual-task conditions. This "attentional boost effect" is reminiscent of findings in the event memory literature, where conditions giving rise to event boundaries have been shown to enhance memory for boundary items. Target detection commonly requires a working memory update (e.g., adding to a covert mental target count), which is also thought to be a key contributor to creating event boundaries. However, whether target detection impacts temporal memory in similar ways as event boundaries remains unknown, because these two parallel literatures have used different types of memory tests, making direct comparisons difficult. In a preregistered experiment with sequential Bayes factor design, we examined whether target detection influences temporal binding between items by inserting target and nontarget stimuli during encoding of trial-unique object images, and then comparing subsequent temporal order and distance memory for image pairs that span a target or nontarget. We found that target detection enhanced recognition memory for target trial images but had no effect on temporal binding between items. In a follow-up experiment, we showed that when the encoding task required updating of task set rather than target count, event segmentation-related temporal memory effects were observed. These results document that target detection as such does not disrupt inter-item associations in memory, and that attention orienting in the absence of updating task sets does not create event boundaries. This suggests a key distinction between declarative and procedural working memory updates in segmenting events in memory. [ABSTRACT FROM AUTHOR]

This study examines declarative memory retrieval in ASD depending on the availability and access to stored conceptual knowledge. Fifteen autistic participants and a matched control group of 18 typically-developed (TD) volunteers completed a Remember-Know paradigm manipulated by encoding-type (categorical, perceptual) and item-typicality (high-typical, low-typical). The autistic group showed worse and slower recognition and less recollection but equivalent familiarity-based memories compared to TDs. Notably, low-typical items did not improve their memories as they did for TDs, likely due to difficulties in matching low-fit information to the stored schema. Results suggest that memory decline in ASD may derive from the episodic system and its dynamics with the semantic system. These findings may inform interventional strategies for enhancing learning abilities in ASD. [ABSTRACT FROM AUTHOR]

Neurofeedback (NF) shows promise in enhancing memory, but its application to the medial temporal lobe (MTL) still needs to be studied. Therefore, we aimed to develop an NF system for the memory function of the MTL and examine neural activity changes and memory task score changes through NF training. We created a memory NF system using intracranial electrodes to acquire and visualise the neural activity of the MTL during memory encoding. Twenty trials of a tug-of-war game per session were employed for NF and designed to control neural activity bidirectionally (Up/Down condition). NF training was conducted with three patients with drug-resistant epilepsy, and we observed an increasing difference in NF signal between conditions (Up–Down) as NF training progressed. Similarities and negative correlation tendencies between the transition of neural activity and the transition of memory function were also observed. Our findings demonstrate NF's potential to modulate MTL activity and memory encoding. Future research needs further improvements to the NF system to validate its effects on memory functions. Nonetheless, this study represents a crucial step in understanding NF's application to memory and provides valuable insights into developing more efficient memory enhancement strategies. [ABSTRACT FROM AUTHOR]

Much evidence suggests that faces are recognized based on their global familiarity in a signal-detection manner. However, experiments drawing this conclusion typically present study lists of faces only once or twice, and the nature of face recognition at higher levels of learning remains unclear. Here, three experiments are reported in which participants studied some faces eight times and others twice and then took a recognition test containing previously viewed faces, entirely new faces, and faces which recombined the parts of previously viewed faces. Three measures converged to suggest that study list repetition increased the likelihood of participants rejecting recombined faces as new by recollecting that their parts were studied but in a different combination, and that manipulating holistic or Gestalt-like processing—a hallmark of face perception—qualitatively preserved its effect on how memory judgments are made. This suggests that face learning causes a shift from the use of a signal-detection strategy to the use of a dual-process strategy of face recognition regardless of holistic processing. [ABSTRACT FROM AUTHOR]

Why can't we remember everything that we experience? Previous work in the domain of object memory has suggested that our ability to resolve interference between relevant and irrelevant object features may limit how much we can remember at any given moment. Here, we developed an online mouse-tracking task to study how memory load influences object reconstruction, testing participants synchronously over virtual conference calls. We first tested up to 18 participants concurrently, replicating memory findings from a condition where participants were tested individually. Next, we examined how memory load influenced mouse trajectories as participants reconstructed target objects. We found interference between the contents of working memory and what was perceived during object reconstruction, an effect that interacted with visual similarity and memory load. Furthermore, we found interference from previously studied but currently irrelevant objects, providing evidence of object-to-location binding errors. At the greatest memory load, participants were nearly three times more likely to move their mouse cursor over previously studied nontarget objects, an effect observed primarily during object reconstruction rather than in the period before the final response. As evidence of the dynamic interplay between working memory and perception, these results show that object reconstruction behavior may be altered by (i) interference between what is represented in mind and what is currently being viewed, and (ii) interference from previously studied but currently irrelevant information. Finally, we discuss how mouse tracking can provide a rich characterization of participant behavior at millisecond temporal resolution, enormously increasing power in cognitive psychology experiments. [ABSTRACT FROM AUTHOR]

The hippocampus is known to be critically involved in associative memory formation. However, the role of the hippocampus during the learning of associative memory is still controversial; while the hippocampus is considered to play a critical role in the integration of related stimuli, numerous studies also suggest a role of the hippocampus in the separation of different memory traces for rapid learning. Here, we employed an associative learning paradigm consisting of repeated learning cycles. By tracking the changes in the hippocampal representations of associated stimuli on a cycle-by-cycle basis as learning progressed, we show that both integration and separation processes occur in the hippocampus with different temporal dynamics. We found that the degree of shared representations for associated stimuli decreased significantly during the early phase of learning, whereas it increased during the later phase of learning. Remarkably, these dynamic temporal changes were observed only for stimulus pairs remembered 1 day or 4 weeks after learning, but not for forgotten pairs. Further, the integration process during learning was prominent in the anterior hippocampus, while the separation process was obvious in the posterior hippocampus. These results demonstrate temporally and spatially dynamic hippocampal processing during learning that can lead to the maintenance of associative memory. [ABSTRACT FROM AUTHOR]

Collaborative recall by groups of people can evoke both memory detriments (e.g., collaborative inhibition) and benefits (e.g., error pruning and post-collaborative memory benefit). Yet, it remains indeterminate whether these effects are due to the emotional valence of stimuli and/or the specific subtypes of episodic memory tested (i.e., item memory and source memory), and whether they are related to the research procedure of directed forgetting (DF). We introduced item-method DF into collaborative memory research using a turn-taking procedure. The to-be-recalled words were studied in different emotional valences and were followed by either an R or F cue, which, respectively, instructed participants to remember or forget the words presented. We conducted two recall sessions (Recall 1 and Recall 2) that included the two subtypes of episodic memory. Recall 1 was performed either individually or collaboratively, while Recall 2 was always performed individually. We observed three major findings: (a) a collaborative memory decrement - collaborative inhibition - was minimally affected in both item memory and source memory tasks by either the emotional valence of the stimuli or the DF cue; (b) a collaborative memory benefit - error pruning of item memory - persisted within both ongoing and post-collaboration, while error pruning of source memory only presented in ongoing collaboration, thus demonstrating the relevance of dual-process models that differentiate automatic familiarity and effortful recollection processes; and (c) there was no post-collaborative memory benefit, indicating the importance of the type of collaborative procedure. We discuss these results in terms of various theories, including the retrieval strategy disruption hypothesis (RSDH) which asserts that memory strategies tend to be disrupted in collaboration but are facilitated within post-collaboration. Also, we describe the implications of these results and directions for exploring other influential factors in future research. [ABSTRACT FROM AUTHOR]

In older adults' everyday life, time-based prospective memory (TBPM) is relevant as health-related intentions are often part of daily activities. Nonetheless, it is still unclear which task-related factors can potentially moderate the magnitude of age-related differences, such as duration of the PM target time (the time-window within which an individual must complete a given TBPM task), the frequency of the TBPM tasks, and the criterion chosen to compute PM accuracy. The present meta-analysis aimed to quantify age-related differences in laboratory TBPM tasks, and to investigate how specific task-related factors potentially moderate the magnitude of age effects. The results showed that age effects consistently emerged among the studies, with older adults showing lower TBPM performance and checking the clock less often than younger adults, especially for shorter intervals (e.g., ≤ 4 min). Furthermore, the results indicated that the duration of the PM target time interacted with the frequency of the PM task, suggesting that learning effects may attenuate the magnitude of age differences in TBPM performance. The results are discussed in terms of potential implications about the possible cognitive processes involved in TBPM and aging, as well as in terms of robustness of the TBPM laboratory paradigm in aging research. [ABSTRACT FROM AUTHOR]

Hearing a task-irrelevant sound during object encoding can improve visual recognition memory when the sound is object-congruent (e.g., a dog and a bark). However, previous studies have only used binary old/new memory tests, which do not distinguish between recognition based on the recollection of details about the studied event or stimulus familiarity. In the present research, we hypothesized that hearing a task-irrelevant but semantically congruent natural sound at encoding would facilitate the formation of richer memory representations, resulting in increased recollection of details of the encoded event. Experiment 1 replicates previous studies showing that participants were more confident about their memory for items that were initially encoded with a congruent sound compared to an incongruent sound. Experiment 2 suggests that congruent object-sound pairings specifically facilitate recollection and not familiarity-based recognition memory, and Experiment 3 demonstrates that this effect was coupled with more accurate memory for audiovisual congruency of the item and sound from encoding rather than another aspect of the episode. These results suggest that even when congruent sounds are task-irrelevant, they promote formation of multisensory memories and subsequent recollection-based retention. Given the ubiquity of encounters with multisensory objects in our everyday lives, considering their impact on episodic memory is integral to building models of memory that apply to naturalistic settings. [ABSTRACT FROM AUTHOR]

We argue that critical areas of memory research rely on problematic measurement practices and provide concrete suggestions to improve the situation. In particular, we highlight the prevalence of memory studies that use tasks (like the "old/new" task: "have you seen this item before? yes/no") where quantifying performance is deeply dependent on counterfactual reasoning that depends on the (unknowable) distribution of underlying memory signals. As a result of this difficulty, different literatures in memory research (e.g., visual working memory, eyewitness identification, picture memory, etc.) have settled on a variety of fundamentally different metrics to get performance measures from such tasks (e.g., A′, corrected hit rate, percent correct, d′, diagnosticity ratios, K values, etc.), even though these metrics make different, contradictory assumptions about the distribution of latent memory signals, and even though all of their assumptions are frequently incorrect. We suggest that in order for the psychology and neuroscience of memory to become a more cumulative, theory-driven science, more attention must be given to measurement issues. We make a concrete suggestion: The default memory task for those simply interested in performance should change from old/new ("did you see this item'?") to two-alternative forced-choice ("which of these two items did you see?"). In situations where old/new variants are preferred (e.g., eyewitness identification; theoretical investigations of the nature of memory signals), receiver operating characteristic (ROC) analysis should be performed rather than a binary old/new task. [ABSTRACT FROM AUTHOR]

Cache bypassing is widely employed to alleviate cache contention and pollution in GPUs. However, cache bypassing often puts more pressure on the network-on-chip (NoC) since the bypassed requests need to traverse the NoC to reach the lower-level memories, thus worsening the NoC congestion. In this paper, we propose an aggressive GPU cache bypassing technique (called SC-Table) to alleviate cache contention and pollution. The SC-Table relies on 2-bit saturating counters (SCs) to store the bypass history of warps. Memory requests issued by a warp are allowed to bypass the L1D when the corresponding SC's value reaches the bypass threshold. In addition, we adopt the monolithic 3D-based NoC (M3D NoC) to provide better NoC throughput and latency. The combination of the SC-Table and the M3D NoC improves GPU performance by 34.6%, on average, over the baseline where there is no cache bypassing and the traditional 2D NoC is adopted. [ABSTRACT FROM AUTHOR]

We memorize our daily life experiences, which are often multisensory in nature, by segmenting them into distinct event models, in accordance with perceived contextual or situational changes. However, very little is known about how multisensory boundaries affect segmentation, as most studies have focused on unisensory (visual or audio) segmentation. In three experiments, we investigated the effect of multisensory boundaries on segmentation in memory and perception. In Experiment 1, participants encoded lists of pictures while audio and visual contexts changed synchronously or asynchronously. After each list, we tested recognition and temporal associative memory for pictures that were encoded in the same audio-visual context or that crossed a synchronous or an asynchronous multisensory change. We found no effect of multisensory synchrony for recognition memory: synchronous and asynchronous changes similarly impaired recognition for pictures encoded at those changes, compared to pictures encoded further away from those changes. Multisensory synchrony did affect temporal associative memory, which was worse for pictures encoded at synchronous than at asynchronous changes. Follow up experiments showed that this effect was not due to the higher dimensionality of multisensory over unisensory contexts (Experiment 2), nor that it was due to the temporal unpredictability of contextual changes inherent to Experiment 1 (Experiment 3). We argue that participants formed situational expectations through multisensory synchronicity, such that synchronous multisensory changes deviated more strongly from those expectations than asynchronous changes. We discuss our findings in light of supportive and conflicting findings of uni- and multi-sensory segmentation. [ABSTRACT FROM AUTHOR]

Previous explorations covering various domains of stereotypes have provided solid evidence that the stereotype-consistent effect, i.e., better memory performance for stereotype-consistent vs. -inconsistent stimuli, emerged exclusively in source memory but not in item memory. Nonetheless, it remains debatable whether this pattern applies to one particular domain, age stereotypes, and to the situation of encountering new objects. To address these issues, the current experiment had 38 undergraduates (18–31 years) study sequential photographs of an elderly or a child performing stereotype-consistent and -inconsistent daily activities. Subsequent memory tests on descriptive phrases adopted the three-key paradigm. Three keys should be pressed respectively to indicate a previously seen action performed by the elderly or the child or new action. Data analyses on the discrimination index of Pr revealed reliable stereotype-inconsistent effect in item memory. Meanwhile, discrepancies arose as the profound stereotype-consistent effect was confirmed in source memory using the conditional source-identification measure (CSIM). For new stimuli, the stereotype-consistent effect also occurred in false alarms as more stereotype-consistent errors were made vs. inconsistent ones. These outcomes indicate that the stereotype-consistent effect occurs among multiple stereotype domains and across memory judgments of both encountered and novel objects considering age stereotypes, strengthening the dual-process model. Implications alerting the potential impairment from stereotypes as well as more research perspectives for future directions are given. [ABSTRACT FROM AUTHOR]

We examined the effect of memory instructions on false memory using the Deese/Roediger–McDermott paradigm in second-language learners. Participants studied lists of words in L1 and L2 (e.g., note, sound, piano...) associatively related to a non-presented critical lure (e.g., MUSIC). In a later recognition test, critical lures appeared in the same or the other language of their lists (i.e., within- and between-language conditions). In Experiment 1, participants should only endorse an item when study and test languages matched (i.e., restrictive instructions); that is, they should retrieve language information. In Experiment 2, participants should endorse studied items regardless of the language (i.e., inclusive instructions). With restrictive instructions, false recognition was higher in within- than between-language conditions, whereas with inclusive instructions, this result was replicated only when words were studied in L1, but not L2. Results suggested that second-language learners show false memory in their L2 and that the effect of language shift on false recognition depended on the study language. [ABSTRACT FROM AUTHOR]

Familiar music facilitates memory retrieval in adults with dementia. However, mechanisms behind this effect, and its generality, are unclear because of a lack of parallel work in healthy aging. Exposure to familiar music enhances spontaneous recall of memories directly cued by the music, but it is unknown whether such effects extend to deliberate recall more generally – e.g., to memories not directly linked to the music being played. It is also unclear whether familiar music boosts recall of specific episodes versus more generalised semantic memories, or whether effects are driven by domain-general mechanisms (e.g., improved mood). In a registered report study, we examined effects of familiar music on deliberate recall in healthy adults ages 65–80 years (N = 75) by presenting familiar music from earlier in life, unfamiliar music, and non-musical audio clips across three sessions. After each clip, we assessed free recall of remote memories for pre-selected events. Contrary to our hypotheses, we found no effects of music exposure on recall of prompted events, though familiar music evoked spontaneous memories most often. These results suggest that effects of familiar music on recall may be limited to memories specifically evoked in response to the music (Preprint and registered report protocol at ). [ABSTRACT FROM AUTHOR]

Long-term memory is achieved through a consolidation process where structural and molecular changes integrate information into a stable memory. However, environmental conditions constantly change, and organisms must adapt their behavior by updating their memories, providing dynamic flexibility for adaptive responses. Consequently, novel stimulation/experiences can be integrated during memory retrieval; where consolidated memories are updated by a dynamic process after the appearance of a prediction error or by the exposure to new information, generating edited memories. This review will discuss the neurobiological systems involved in memory updating including recognition memory and emotional memories. In this regard, we will review the salient and emotional experiences that promote the gradual shifting from displeasure to pleasure (or vice versa), leading to hedonic or aversive responses, throughout memory updating. Finally, we will discuss evidence regarding memory updating and its potential clinical implication in drug addiction, phobias, and post traumatic stress disorder. [ABSTRACT FROM AUTHOR]

Previous studies have confirmed that collaboration in memory can elicit reliable impairment (e.g. collaborative inhibition) and enhancement (e.g. error pruning and post-collaborative recall benefit). However, there is scarce research considering whether these phenomena would occur in semantically related stimuli, especially when in different episodic memory tasks. After encoding some exemplars of certain categories, participants were instructed to sequentially recall originally studied exemplars (item recall) and their encoding colors (source retrieval). The tests were performed twice (Recall 1 and Recall 2), with Recall 1 been done either individually or collaboratively, whereas Recall 2 was an individual test. We replicated the detrimental effect of collaborative inhibition, as well as two beneficial effects of error pruning and post-collaborative recall benefit. Besides, both collaborative inhibition and post-collaborative recall benefit were sensitive to episodic memory tasks; meanwhile, the indicators of both item-specific processing and relational processing were modulated by memory tasks. The novel implications are: (a) revealing that effects of collaborative memory are sensitive to memory tasks; (b) extending the occurrence of a beneficial effect of error pruning to categorized lists; as well as (c) demonstrating that collaboration can attenuate the item-specific processing but enhance the relational processing, and such influences are susceptible to memory tasks. Thus, our findings provide compelling evidence for both the dual-process memory theory and the retrieval strategy disruption hypothesis. Future research is recommended to examine more influential factors. [ABSTRACT FROM AUTHOR]

Orienting toward the meaning versus perceptual features of an experience benefits subsequent memory. Yet given that past work encouraged these orientations with different tasks, it is not clear if this memory benefit is solely due to internal processing factors versus external task-related ones. Moreover, it remains unclear how this benefit generalises from verbal to detailed picture memory. Here, we developed a novel paradigm that cued participants' attention to thematic (story) or stylistic (artist style) dimensions of storybook-style illustrations during a repeat-detection task. Afterwards, participants completed a recognition memory test with studied illustrations and lures along thematic and stylistic dimensions. In contrast to past work, both orienting tasks were identical except for the dimension participants were cued to attend to. Furthermore, our thematic and stylistic dimensions enabled us to separately examine memory quality along each dimension. We found that thematic attention yielded superior memory for studied illustrations over stylistic orientations. False alarms to lures varied by dimension and attention: errors were greater to thematic than stylistic lures overall and stylistic attention elevated false alarms to stylistic lures. Our results show that semantic encoding orientations enhance detailed picture memory, without a cost to memory quality along semantic or perceptual dimensions of experience. [ABSTRACT FROM AUTHOR]

Study objectives: Novel information is rapidly learned when it is compatible with previous knowledge. This "schema" effect, initially described for declarative memories, was recently extended to the motor memory domain. Importantly, this beneficial effect was only observed 24 hours–but not immediately–following motor schema acquisition. Given the established role of sleep in memory consolidation, we hypothesized that sleep following the initial learning of a schema is necessary for the subsequent rapid integration of novel motor information. Methods: Two experiments were conducted to investigate the effect of diurnal and nocturnal sleep on schema-mediated motor sequence memory consolidation. In Experiment 1, participants first learned an 8-element motor sequence through repeated practice (Session 1). They were then afforded a 90-minute nap opportunity (N = 25) or remained awake (N = 25) before learning a second motor sequence (Session 2) which was highly compatible with that learned prior to the sleep/wake interval. Experiment 2 was similar; however, Sessions 1 and 2 were separated by a 12-hour interval that included nocturnal sleep (N = 28) or only wakefulness (N = 29). Results: For both experiments, we found no group differences in motor sequence performance (reaction time and accuracy) following the sleep/wake interval. Furthermore, in Experiment 1, we found no correlation between sleep features (non-REM sleep duration, spindle and slow wave activity) and post-sleep behavioral performance. Conclusions: The results of this research suggest that integration of novel motor information into a cognitive-motor schema does not specifically benefit from post-learning sleep. [ABSTRACT FROM AUTHOR]

The function of long-term memory is not just to reminisce about the past, but also to make predictions that help us behave appropriately and efficiently in the future. This predictive function of memory provides a new perspective on the classic question from memory research of why we remember some things but not others. If prediction is a key outcome of memory, then the extent to which an item generates a prediction signifies that this information already exists in memory and need not be encoded. We tested this principle using human intracranial EEG as a time-resolved method to quantify prediction in visual cortex during a statistical learning task and link the strength of these predictions to subsequent episodic memory behavior. Epilepsy patients of both sexes viewed rapid streams of scenes, some of which contained regularities that allowed the category of the next scene to be predicted. We verified that statistical learning occurred using neural frequency tagging and measured category prediction with multivariate pattern analysis. Although neural prediction was robust overall, this was driven entirely by predictive items that were subsequently forgotten. Such interference provides a mechanism by which prediction can regulate memory formation to prioritize encoding of information that could help learn new predictive relationships. [ABSTRACT FROM AUTHOR]

When we remember events, we often do not only recall individual events, but also the connections between them. However, extant research has focused on how humans segment and remember discrete events from continuous input, with far less attention given to how the structure of connections between events impacts memory. Here we conduct a functional magnetic resonance imaging study in which participants watch and recall a series of realistic audiovisual narratives. By transforming narratives into networks of events, we demonstrate that more central events—those with stronger semantic or causal connections to other events—are better remembered. During encoding, central events evoke larger hippocampal event boundary responses associated with memory formation. During recall, high centrality is associated with stronger activation in cortical areas involved in episodic recollection, and more similar neural representations across individuals. Together, these results suggest that when humans encode and retrieve complex real-world experiences, the reliability and accessibility of memory representations is shaped by their location within a network of events. Naturalistic experiences often have complex structure, consisting of multiple inter-related events. Here, the authors show that the semantic and causal interconnectedness of events in narratives positively predicts memory performance and neural responses associated with memory encoding and recall. [ABSTRACT FROM AUTHOR]

The hippocampus has been a focus of memory research since H.M's surgery abolished his ability to form new memories, yet its mechanistic role in memory remains debated. Here, we identify a candidate memory mechanism: an anticipatory hippocampal "convergence state", observed while awaiting valuable information, and which predicts subsequent learning. During fMRI, participants viewed trivia questions eliciting high or low curiosity, followed seconds later by its answer. We reasoned that encoding success requires a confluence of conditions, so that hippocampal states more conducive to memory formation should converge in state space. To operationalize convergence of neural states, we quantified the typicality of multivoxel patterns in the medial temporal lobes during anticipation and encoding of trivia answers. We found that the typicality of anticipatory hippocampal patterns increased during high curiosity. Crucially, anticipatory hippocampal pattern typicality increased with dopaminergic midbrain activation and uniquely accounted for the association between midbrain activation and subsequent recall. We propose that hippocampal convergence states may complete a cascade from motivation and midbrain activation to memory enhancement, and may be a general predictor of memory formation. Motivational states play a key role in memory formation. Here, the authors show that curiosity engages reward circuitry to promote a hippocampal state conducive to the formation of new memories. [ABSTRACT FROM AUTHOR]

The hippocampus has been a focus of memory research since H.M's surgery abolished his ability to form new memories, yet its mechanistic role in memory remains debated. Here, we identify a candidate memory mechanism: an anticipatory hippocampal "convergence state", observed while awaiting valuable information, and which predicts subsequent learning. During fMRI, participants viewed trivia questions eliciting high or low curiosity, followed seconds later by its answer. We reasoned that encoding success requires a confluence of conditions, so that hippocampal states more conducive to memory formation should converge in state space. To operationalize convergence of neural states, we quantified the typicality of multivoxel patterns in the medial temporal lobes during anticipation and encoding of trivia answers. We found that the typicality of anticipatory hippocampal patterns increased during high curiosity. Crucially, anticipatory hippocampal pattern typicality increased with dopaminergic midbrain activation and uniquely accounted for the association between midbrain activation and subsequent recall. We propose that hippocampal convergence states may complete a cascade from motivation and midbrain activation to memory enhancement, and may be a general predictor of memory formation. Motivational states play a key role in memory formation. Here, the authors show that curiosity engages reward circuitry to promote a hippocampal state conducive to the formation of new memories. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effect of experimentally delivered acute pain on memory. Twenty-five participants participated in experimental sessions on consecutive days. The first session involved a categorization task to encourage memory encoding. There were two conditions, presented in randomized order, in which participants listened to a series of words, which were repeated three times. In one condition, one-third of the word items were immediately followed by a painful electrical shock. This word-shock pairing was consistent across repetition and the pain-paired items were presented unpredictably. In the other condition, all word items were not associated with pain. Response times over these repeated presentations were assessed for differences. Explicit memory was tested the following day, employing a Remember–Know assessment of word recognition, with no shocks employed. We found evidence that recollection may be reduced for pain-paired words, as the proportion of correct Remember responses (out of total correct responses) was significantly lower. There were no significant reductions in memory for non-pain items that followed painful stimulation after a period of several seconds. Consistent with the experience of pain consuming working memory resources, we theorize that painful shocks interrupt memory encoding for the immediately preceding experimental items, due to a shift in attention away from the word item. [ABSTRACT FROM AUTHOR]

Exploration of a novel environment has been shown to promote memory formation in healthy adults. Studies in animals have suggested that such novelty-induced memory boosts are mediated by hippocampal dopamine. The dopaminergic system is known to develop and deteriorate over the lifespan, but so far, the effects of novelty on memory across the lifespan have not yet been investigated. In the current study, we had children, adolescents, younger, and older adults (n = 439) explore novel and previously familiarized virtual environments to pinpoint the effects of spatial novelty on declarative memory in humans across different age groups. After exploration, words were presented while participants performed a deep or shallow encoding task. Incidental memory was quantified in a surprise test. Results showed that participants in the deep encoding condition remembered more words than those in the shallow condition, while novelty did not influence this effect. Interestingly, however, children, adolescents and younger adults benefitted from exploring a novel compared to a familiar environment as evidenced by better word recall, while these effects were absent in older adults. Our findings suggest that the beneficial effects of novelty on memory follow the deterioration of neural pathways involved in novelty-related processes across the lifespan. [ABSTRACT FROM AUTHOR]

How do violations of predictability and plausibility affect online language processing? How does it affect longer-term memory and learning when predictions are disconfirmed by plausible or implausible words? We investigated these questions using a self-paced sentence reading and noun recognition task. Critical sentences violated predictability or plausibility or both, for example, "Since Anne is afraid of spiders, she doesn't like going down into the ... basement (predictable, plausible), garden (unpredictable, somewhat plausible), moon (unpredictable, deeply implausible)." Results from sentence reading showed earlier-emerging effects of predictability violations on the critical noun, but later-emerging effects of plausibility violations after the noun. Recognition memory was exclusively enhanced for deeply implausible nouns. The earlier-emerging predictability effect indicates that having word form predictions disconfirmed is registered very early in the processing stream, irrespective of semantics. The later-emerging plausibility effect supports models that argue for a staged architecture of reading comprehension, where plausibility only affects a post-lexical integration stage. Our memory results suggest that, in order to facilitate memory and learning, a certain magnitude of prediction error is required. [ABSTRACT FROM AUTHOR]

To efficiently process information, the brain shifts between encoding and retrieval states, prioritizing bottom-up or top-down processing accordingly. Expectation violation before or during learning has been shown to trigger an adaptive encoding mechanism, resulting in better memory for unexpected events. Using fMRI, we explored (1) whether this encoding mechanism is also triggered during retrieval, and if so, (2) what the temporal dynamics of its mnemonic consequences are. Male and female participants studied object images, then, with new objects, they learned a contingency between a cue and a semantic category. Rule-abiding (expected) and violating (unexpected) targets and similar foils were used at test. We found interactions between previous and current similar events' expectation, such that when an expected event followed a similar but unexpected event, its performance was boosted, underpinned by activation in the hippocampus, midbrain, and occipital cortex. In contrast, a sequence of two unexpected similar events also triggered occipital engagement; however, this did not enhance memory performance. Taken together, our findings suggest that when the goal is to retrieve, encountering surprising events engages an encoding mechanism, supported by bottom-up processing, that may enhance memory for future related events. [ABSTRACT FROM AUTHOR]

The incidental acquisition of multimodal associations is a key memory function for everyday life. While the posterior parietal cortex has been frequently shown to be involved for these memory functions, ventral and dorsal regions revealed differences in their functional recruitment and the precise difference in multimodal memory processing with respect to the associative process has not been differentiated. Using an incidental multimodal learning task, we isolated the associative process during multimodal learning and recollection. The result of the present functional magnetic resonance imaging (fMRI) study demonstrated that during both learning and recollection a clear functional differentiation between ventral and dorsal posterior parietal regions was found and can be related directly to the associative process. The recruitment of a ventral region, the angular gyrus, was specific for learning and recollection of multimodal associations. In contrast, a dorsal region, the superior parietal lobule, could be attributed to memory guided attentional processing. Independent of the memory stage, we assumed a general role for the angular gyrus in the generation of associative representations and updating of fixed association, episodic memory. [ABSTRACT FROM AUTHOR]

Novelty is defined as the part of an experience that is not yet represented by memory systems. Novelty has been claimed to exert various memory‐enhancing effects. A pioneering study by Wittmann et al. (2007) has shown that memory formation may even benefit from the expectation of novelty. We aimed to replicate this assumed memory effect in four behavioral studies. However, our results do not support the idea that anticipated novel stimuli are more memorable than unexpected novelty. In our experiments, we systematically manipulated the novelty predicting cues to ensure that the expectations were correctly formed by the participants, however, the results showed that there was no memory enhancement for expected novel pictures in any of the examined indices, thus we could not replicate the main behavioral finding of Wittmann et al. (2007). These results call into question the original effect, and we argue that this fits more into current thinking on memory formation and brain function in general. Our results are more consistent with the view that unexpected stimuli are more likely to be retained by memory systems. Predictive coding theory suggests that unexpected stimuli are prioritized by the nervous system and this may also benefit memory processes. Novel stimuli may be unexpected and thus recognized better in some experimental setups, yet novelty and unexpectedness do not always coincide. We hope that our work can bring more consistency in the literature on novelty, as educational methods in general could also benefit from this clarification. [ABSTRACT FROM AUTHOR]

When we remember events, we often do not only recall individual events, but also the connections between them. However, extant research has focused on how humans segment and remember discrete events from continuous input, with far less attention given to how the structure of connections between events impacts memory. Here we conduct a functional magnetic resonance imaging study in which participants watch and recall a series of realistic audiovisual narratives. By transforming narratives into networks of events, we demonstrate that more central events—those with stronger semantic or causal connections to other events—are better remembered. During encoding, central events evoke larger hippocampal event boundary responses associated with memory formation. During recall, high centrality is associated with stronger activation in cortical areas involved in episodic recollection, and more similar neural representations across individuals. Together, these results suggest that when humans encode and retrieve complex real-world experiences, the reliability and accessibility of memory representations is shaped by their location within a network of events. Naturalistic experiences often have complex structure, consisting of multiple inter-related events. Here, the authors show that the semantic and causal interconnectedness of events in narratives positively predicts memory performance and neural responses associated with memory encoding and recall. [ABSTRACT FROM AUTHOR]

Sleep deprivation is known to have adverse effects on various cognitive abilities. In particular, a lack of sleep has been reported to disrupt memory consolidation and cognitive control functions. Here, focusing on long-term memory and cognitive control processes, we review the consistency and reliability of the results of previous studies of sleep deprivation effects on behavioral performance with variations in the types of stimuli and tasks. Moreover, we examine neural response changes related to these behavioral changes induced by sleep deprivation based on human fMRI studies to determine the brain regions in which neural responses increase or decrease as a consequence of sleep deprivation. Additionally, we discuss about the possibility that light as an environmentally influential factor affects our sleep cycles and related cognitive processes. [ABSTRACT FROM AUTHOR]

Incorporating 3D virtual environments into psychological experiments offers an innovative solution for balancing experimental control and ecological validity. Their flexible application to virtual navigation experiments, however, has been limited because accessible development tools best support only a subset of desirable task design features. We created OpenMaze, an open-source toolbox for the Unity game engine, to overcome this barrier. OpenMaze offers researchers the ability to conduct a wide range of first-person spatial navigation experiment paradigms in fully customized 3D environments. Crucially, because all experiments are defined using human-readable configuration files, our toolbox allows even those with no prior coding experience to build bespoke tasks. OpenMaze is also compatible with a variety of input devices and operating systems, broadening its possible applications. To demonstrate its advantages and limitations, we review and contrast other available software options before providing an overview of our design objectives and walking the reader through the process of building an experiment in OpenMaze. [ABSTRACT FROM AUTHOR]

We investigated how aerobic exercise during encoding affects hippocampus-dependent memory through a source memory task that assessed hippocampus-independent familiarity and hippocampus-dependent recollection processes. Using a within-participants design, young adult participants performed a memory-encoding task while performing a cycling exercise or being seated. The subsequent retrieval phase was conducted while sitting on a chair. We assessed behavioral and event-related brain potential measures of familiarity and recollection processes during the retrieval phase. Results indicated that source accuracy was lower for encoding with exercise than for encoding in the resting condition. Event-related brain potential measures indicated that the parietal old/new effect, which has been linked to recollection processing, was observed in the exercise condition, whereas it was absent in the rest condition, which is indicative of exercise-induced hippocampal activation. These findings suggest that aerobic exercise during encoding impairs hippocampus-dependent memory, which may be attributed to inefficient source encoding during aerobic exercise. [ABSTRACT FROM AUTHOR]

Attention has been shown to enhance the processing of task-relevant information while suppressing the processing of task-irrelevant information. However, it is less clear whether this attentional modulation exists when there is an intrinsic dependence between task-relevant and task-irrelevant information, such as the dependence of temporal processing on spatial information. In this study, we used complex whole-body movement sequences to investigate the extent to which the task-irrelevant spatial information (trajectory) is processed when only the temporal information (rhythm) is in focus. Moreover, we examined, if the task-irrelevant spatial information is "co-selected" with the target temporal information as predicted by the intrinsic spatiotemporal dependence, whether task-driven attention that is actively directed to spatial information provides extra benefits. Through a two-phase experiment (an incidental encoding phase followed by a surprise memory test phase), we found that the task-irrelevant spatial information was not only perceived but also encoded in memory, providing further evidence in support of a relatively automatic co-selection of spatial information in temporal processing. Nevertheless, we also found that movements whose trajectories were intentionally attended to during the encoding phase were recognized better in the test phase than those that were not, indicating a further modulation from attention on incidental memory encoding and information processing. [ABSTRACT FROM AUTHOR]

The ability to generate associative representations and to retrieve them from long-term episodic memory generally declines in healthy aging. However, it is unclear whether healthy aging has differential effects on associative memory for identity, spatial configuration, and temporal order relationships. In the current study, we assessed how healthy aging impacts on associative memory for identity, spatial, or temporal relationships between pairs of visual objects via discrimination of intact and rearranged pairs. Accuracy and response time performance of healthy older adults (aged 65–80) were compared with young adults (ages 19–30). Age-related declines in associative memory were observed equally for all types of associations, but these declines differed by associative status: aging most strongly affected ability to discriminate rearranged pairs. These results suggest that associative memory for identity, spatial, and temporal relationships are equally affected by healthy aging, and may all depend on a shared set of basic associative mechanisms. [ABSTRACT FROM AUTHOR]

Most current models of recognition memory fail to separately model item and person heterogeneity which makes it difficult to assess ability at the latent construct level and prevents the administration of adaptive tests. Here we propose to employ a General Condorcet Model for Recognition (GCMR) in order to estimate ability, response bias and item difficulty in dichotomous recognition memory tasks. Using a Bayesian modeling framework and MCMC inference, we perform 3 separate validation studies comparing GCMR to the Rasch model from IRT and the 2-High-Threshold (2HT) recognition model. First, two simulations demonstrate that recovery of GCMR ability estimates with varying sparsity and test difficulty is more robust and that estimates improve from the two other models under common test scenarios. Then, using a real dataset, face validity is confirmed by replicating previous findings of general and domain-specific age effects (Güsten et al. in Cortex 137:138–148, https://doi.org/10.1016/j.cortex.2020.12.017, 2021). Using cross-validation we show better out-of-sample prediction for the GCMR as compared to Rasch and 2HT model. In addition, we present a hierarchical extension of the model that is able to estimate age- and domain-specific effects directly, without recurring to a two-stage procedure. Finally, an adaptive test using the GCMR is simulated, showing that the test length necessary to obtain reliable ability estimates can be significantly reduced compared to a non-adaptive procedure. The GCMR allows to model trial-by-trial performance and to increase the efficiency and reliability of recognition memory assessments. [ABSTRACT FROM AUTHOR]

This work examines the influence of stored conceptual knowledge (i.e., schema and item-typicality) on conscious memory processes. Specifically, we tested whether item-typicality selectively modulates recollection and familiarity-based memories as a function of the availability of a categorical schema during encoding. Experiment 1 manipulated both encoding type (categorical vs. perceptual) and item-typicality (typical vs. atypical) in a single Remember-Know paradigm. Experiment 2 replicated and extended the previous study with a complementary source-memory task. In both experiments, we observed that typical items led to more Guess responses, while atypical items led to more Remember responses. These findings support the idea that the activation of a congruent categorical schema selectively enhances familiarity-based memories, likely due to the bypassing of the activated mechanisms for novel information. In contrast, atypical items improved recollective-based memories only, suggesting that their lesser fit with the stored prototype might have triggered those novelty processing mechanisms. Moreover, atypical items enhanced memory in the categorical condition for both item recognition and recollection memories only, suggesting an episodic gain due to inconsistency/novelty. The source memory results gave further credence to the argument that "Remember" judgments were based on truly recollective experiences and presented the same interaction between encoding type and item-typicality observed in recollective-based memories. Overall, the results suggest that the supposedly opposite conceptual knowledge effects actually coexist and interact, albeit selectively, in the modulation of recollection and familiarity processes. [ABSTRACT FROM AUTHOR]

The COVID-19 virus has a neuropsychiatric impact, including mild cognitive impairment. Most severe traumas negatively impact executive functions. However, the impact of COVID-19 trauma on cognition is unknown. To test the effects of COVID-19 traumatic stress on executive functions, we surveyed 417 Syrian refugees using measures for COVID-19 traumatic stress, executive functions, PTSD, depression, and anxiety. Using step multiple regression and PROCESS mediation analysis, COVID-19 traumatic stress and its three fears, economic and social components, directly and indirectly, affect increased working memory and inhibition deficits via PTSD and depression. We discussed the conceptual and clinical implications of the results. [ABSTRACT FROM AUTHOR]