Passive but Accessible: Studied Information Is Not Actively Stored in Working Memory, Yet Attended Regardless of Anticipated Load.

High-resolution fMRI data reveal an often-neglected contribution of the medial temporal lobe circuitry to item-specific representation in visual working memory, suggesting the mechanism traditionally deemed dedicated to long-term memory can be exploited to support the quality of human working memory.

High-resolution fMRI data reveal an often-neglected contribution of the medial temporal lobe circuitry to item-specific representation in visual working memory, suggesting the mechanism traditionally deemed dedicated to long-term memory can be exploited to support the quality of human working memory.

Semantic-based audiovisual integration enhances active storage in visual working memory.

Neural correlates of relational and item-specific encoding during working and long-term memory in schizophrenia

Neural measures of working memory in a bilateral change detection task.

The reactivation of task rules triggers the reactivation of task-relevant items

The presence of memory for rejected distractors during visual search has been heavily debated in the literature and has proven challenging to investigate behaviorally. In this research, we used an electrophysiological index of working memory (contralateral delay activity) to passively measure working memory activity during visual search. Participants were asked to indicate whether a novel target was present or absent in a lateralized search array with three visual set sizes (2, 4, or 6). If rejected distractors are maintained in working memory during search, working memory activity should increase with the number of distractors that need to be evaluated. Therefore, we predicted the amplitude of the contralateral delay activity would be larger for target-absent trials and would increase with visual set size until WM capacity was reached. In Experiment 1, we found no evidence for distractor maintenance in working memory during search for real-world stimuli. In Experiment 2, we found partial evidence in support of distractor maintenance during search for stimuli with high target/distractor similarity. In both experiments, working memory capacity did not appear to be a limiting factor during visual search. These results suggest the role of working memory during search may depend on the visual search task in question. Maintaining distractors in working memory appears to be unnecessary during search for realistic stimuli. However, there appears to be a limited role for distractor maintenance during search for artificial stimuli with a high degree of feature overlap.

FIGURE 1. The Atkinson and Shiffrin Model of memory is diagramed in the gray panel. Sensory information is perceived and suppressed via selective attention processes, then briefly held in the limited-capacity modality-specific sensory register. Information enhanced by selective attention enters into short term memory (STM). The process of rehearsal (maintenance) can sustain information in STM. Information in STM is automatically encoded (stored, consolidated) into long term memory (LTM). Although flawed, this model continues to provide a simple and easy approach to understanding memory. Assumptions that proved to be inconsistent with research included that any information in STM will transfer to LTM and that STM is required

In Hybrid Search, observers search for any member of a set of targets held in memory. Current hybrid search models propose working memory (WM) serves to pass representations of attended items one at a time from early visual processes into long-term memory (LTM) for comparison to target representations (Drew, et al., 2015). Here, we sought to better understand the role of WM in hybrid search using an ERP component associated with WM load, the Contralateral Delay Activity (CDA). Participants (N=20) memorized setsizes (MSS) of 2 or 16 categorical targets (dogs, cats, tables, or dressers), counterbalanced across participants. Next, they passed a recognition memory test twice with >=80% accuracy. Then, for 700 trials (per MSS), participants were cued to attend to one lateralized search item and indicate if a target was present. The cued object was either a target (e.g., target cat), a non-target from the target category (e.g., non-target cat), a non-target from a similar category (e.g., dog), or a non-target from a dissimilar category (e.g., table). ERP waveforms were time-locked to search onset. Overall, CDA amplitude was larger for objects from the target category, which provides support for the idea that processing is terminated for irrelevant objects following initial object identification (Cunningham & Wolfe, 2014). For objects within the target category, CDA amplitude increased with MSS, suggesting LTM load-dependent WM involvement in hybrid search. Furthermore, N2pc amplitude increased as the non-targets became more similar to the object category, but only for MSS16. This suggests more non-targets with similar features were selected for further processing in memory at larger MSS. Together, these findings demonstrate WM plays a larger role in hybrid search than previously thought. Specifically, to identify objects within the target category, WM resources may be deployed to compare the target set held in LTM to the potential target.

Applying the Science of Learning to Classroom Teaching: The Critical Importance of Aligning Learning with Testing

IntroductionPrevious research has presented contradictory findings regarding emotional memory enhancement, often demonstrating an “angry face advantage” in working memory (WM) and a “happy face advantage” in long-term memory (LTM). However, the relationship between emotional memory enhancements in WM and LTM, particularly at the individual level, remains unclear. This study investigated the change in emotional memory for happy versus angry faces from immediate to delayed recognition and explored the individual-level correlation between WM and LTM performance.MethodsA memory experiment was conducted over two consecutive days. On the first day, participants completed a change-detection task to measure WM for angry and happy faces. Approximately 24 h later, a surprise LTM recognition task was administered to assess the memory of the facial identities encountered during the WM task. This study measured WM capacity and LTM sensitivity for both emotional faces, and a correlation analysis was performed between individual bias scores (difference in memory for happy versus angry faces) in WM and LTM tasks.ResultsThere was no significant difference in memory capacity in the group-level analysis of WM performance for happy and angry faces. In contrast, the delayed LTM test showed a robust happy face advantage, with significantly better recognition of faces initially encountered with happy expressions than with angry expressions. Most critically, the correlation analysis revealed a significant negative relationship between WM and LTM emotional biases, indicating that individuals with relatively better WM performance for one emotional valence subsequently exhibited a reduced LTM advantage for the same valence.DiscussionThe negative correlation between WM and LTM emotional biases aligns with the arousal-biased competition model, suggesting that the cognitive resources allocated to maintaining threatening information in WM may come at the cost of elaborate encoding processes necessary for robust LTM consolidation. These results provide novel evidence for a compensatory processing mechanism wherein the cognitive system manages immediate and delayed memories of emotional faces in a complementary rather than cumulative fashion.

Working memory (WM) capacity has been claimed to be larger for meaningful objects than for simple features, possibly because richer semantic representations enhance item distinctiveness. However, prior demonstrations compared trial-unique meaningful objects with a small set of repeated simple features. This design confounds meaningfulness with proactive interference (PI), such that PI is minimal for trial-unique objects but substantial for repeated features. Therefore, superior performance for meaningful objects may reflect contributions from episodic long-term memory (LTM) rather than expanded WM capacity. To test this, Experiment 1 measured WM for repeated colors, repeated meaningful objects, and trial-unique meaningful objects from 31 human observers (18 females). The advantage for objects over colors was replicated in the trial-unique condition but eliminated for repeated objects that equated PI across stimulus types. Hierarchical Bayesian dual-process modeling revealed that this advantage reflected stronger familiarity signals, whereas recollection remained stable across stimulus types. Experiment 2 assessed WM storage directly using contralateral delay activity (CDA), an electrophysiological marker of the number of items stored, from 25 observers (14 females). Although trial-unique objects again yielded behavioral advantages, CDA activity across increasing set sizes revealed a common slope and plateau for trial-unique meaningful objects and repeated colors. The CDA difference between stimulus types was additive and did not vary with the set size, providing no evidence for increased WM storage. These findings suggest that object advantages in WM reflect reduced PI and enhanced contributions from LTM. When PI is equated, WM storage limits for simple and meaningful stimuli are equivalent.

Goal-directed behavior relies on cognitive flexibility – the ability to rapidly adapt ongoing thoughts and behaviors while preserving task-relevant information. The performance monitoring system optimizes such behavior by detecting and evaluating errors, while the working memory (WM) system maintains relevant information and protects it from interference. We investigated how these two systems interact. In prior work (Wessel et al., 2022), we found that motor errors impaired active WM maintenance (Error-Related Impairment of Active working Memory; ERIAM). Here, we aimed to identify the source of ERIAM by tracking a neurophysiological marker of visual WM maintenance – the contralateral delay activity (CDA) – throughout the error-making process. Forty-two human participants maintained visual information in WM while performing a motoric task during the delay period. Consistent with prior results, a significant ERIAM effect occurred: motor errors impaired WM performance. Critically, CDA amplitudes did not differ between motor correct and error trials before the flanker task, ruling out a general performance deficit. The CDA was also unaffected immediately after flankers, ruling out a perceptual interference explanation. Significant CDA differences only emerged after motor errors, supporting a genuinely error-related origin of the ERIAM effect. Contrary to prediction, however, CDA was more disrupted after correct responses than errors, and greater disruptions predicted a smaller ERIAM effect. These findings suggest that participants might store WM in multiple states to reduce interference from errors and that the CDA dynamics reflect these adaptive shielding strategies. These findings provide new insights into the source of error-related interference in active WM.

The neural correlations of spatial attention and working memory deficits in adults with ADHD

Previous research indicates that long-term memory (LTM) may contribute to performance in working memory (WM) tasks. Across 3 experiments, we investigated the extent to which active maintenance in WM can be replaced by relying on information stored in episodic LTM, thereby freeing capacity for additional information in WM. First, participants encoded word pairs into LTM, and then completed a WM task, also involving word pairs. Crucially, the pairs presented in each WM trial comprised varying numbers of new pairs and the previously learned LTM pairs. Experiment 1 showed that recall performance in the WM task was unaffected when memory set size increased through the addition of LTM pairs, but that it deteriorated when set size increased through adding new pairs. In Experiment 2, we investigated the robustness of this effect, orthogonally manipulating the number of new and LTM pairs used in the WM task. When WM load was low, performance declined with the addition of LTM pairs but remained superior to performance with the matched set size comprising only new pairs. By contrast, when WM load was higher, adding LTM pairs did not affect performance. In Experiment 3, we found that the benefit of LTM representations arises from retrieving these during the WM test, leading them to suffer from typical interference effects. We conclude that individuals can outsource workload to LTM to optimize performance, and that the WM system negotiates the exchange of information between WM and LTM depending on the current memory load. (PsycInfo Database Record (c) 2022 APA, all rights reserved).