scholarly journals Recruitment of a long-term memory supporting neural network during repeated maintenance of a multi-item abstract visual image in working memory

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Klaartje T. H. Heinen ◽  
J. Leon Kenemans ◽  
Stefan van der Stigchel

AbstractHumans can flexibly transfer information between different memory systems. Information in visual working memory (VWM) can for instance be stored in long-term memory (LTM). Conversely, information can be retrieved from LTM and temporarily held in WM when needed. It has previously been suggested that a neural transition from parietal- to midfrontal activity during repeated visual search reflects transfer of information from WM to LTM. Whether this neural transition indeed reflects consolidation and is also observed when memorizing a rich visual scene (rather than responding to a single target), is not known. To investigate this, we employed an EEG paradigm, in which abstract six-item colour-arrays were repeatedly memorized and explicitly visualized, or merely attended to. Importantly, we tested the functional significance of a potential neural shift for longer-term consolidation in a subsequent recognition task. Our results show a gradually enhanced- and sustained modulation of the midfrontal P170 component and a decline in parietal CDA, during repeated WM maintenance. Improved recollection/visualization of memoranda upon WM-cueing, was associated with contralateral parietal- and right temporal activity. Importantly, only colour-arrays previously held in WM, induced a greater midfrontal P170-response, together with left temporal- and late centro-parietal activity, upon re-exposure. These findings provide evidence for recruitment of an LTM-supporting neural network which facilitates visual WM maintenance.

2021 ◽  
Author(s):  
Klaartje T.H. Heinen ◽  
J. Leon Kenemans ◽  
Stefan Van der Stigchel

Abstract Humans can flexibly transfer information between different memory systems. Information in visual working memory (VWM) can for instance be stored in long-term memory (LTM) when a scene is repeatedly memorized. Conversely, information can be retrieved from LTM and temporarily held in WM when needed. It has previously been suggested that a neural transition from parietal- to midfrontal activity reflects transfer of information from WM to LTM during repeated visual search for the same single item. However, whether these observed neural changes truly represent consolidation and are also observed when memorizing and (explicitly) recollecting a rich visual scene (rather than a single target), remains unclear. The current EEG study investigates whether such a gradual shift in memory-correlates is also observed when an abstract colour-array is repeatedly memorized and explicitly recollected in a WM paradigm. Importantly, we tested the functional significance of a neural shift for longer-term consolidation in a subsequent recognition task. Our results provide supporting evidence for recruitment of an LTM-supporting storage system during WM, which facilitates visual WM maintenance and is indexed by (sustained) modulation of a midfrontal component. Enhanced explicit memory recollection during WM is associated with- and possibly facilitated by an emerging late contralateral parietal activity.


2019 ◽  
Author(s):  
Annalise Miner ◽  
Mark Schurgin ◽  
Timothy F. Brady

Long-term memory is often considered easily corruptible, imprecise and inaccurate, especially in comparison to working memory. However, most research used to support these findings relies on weak long-term memories: those where people have had only one brief exposure to an item. Here we investigated the fidelity of visual long-term memory in more naturalistic setting, with repeated exposures, and ask how it compares to visual working memory fidelity. Using psychophysical methods designed to precisely measure the fidelity of visual memory, we demonstrate that long-term memory for the color of frequently seen objects is as accurate as working memory for the color of a single item seen 1 second ago. In particular, we show that repetition greatly improves long-term memory, including the ability to discriminate an item from a very similar item ('fidelity'), in both a lab setting (Exps. 1-3) and a naturalistic setting (brand logos, Exp. 4). Overall our results demonstrate the impressive nature of visual long-term memory fidelity, which we find is even higher fidelity than previously indicated in situations involving repetitions. Furthermore, our results suggest that there is no distinction between the fidelity of visual working memory and visual long-term memory, but instead both memory systems are capable of storing similar incredibly high fidelity memories under the right circumstances. Our results also provide further evidence that there is no fundamental distinction between the ‘precision’ of memory and the ‘likelihood of retrieving a memory’, instead suggesting a single continuous measure of memory strength best accounts for working and long-term memory.


Biology ◽  
2014 ◽  
Vol 4 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Barbara Berger ◽  
Serif Omer ◽  
Tamas Minarik ◽  
Annette Sterr ◽  
Paul Sauseng

2018 ◽  
Vol 30 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Natalie Biderman ◽  
Roy Luria ◽  
Andrei R. Teodorescu ◽  
Ron Hajaj ◽  
Yonatan Goshen-Gottstein

How detailed are long-term-memory representations compared with working memory representations? Recent research has found an equal fidelity bound for both memory systems, suggesting a novel general constraint on memory. Here, we assessed the replicability of this discovery. Participants (total N = 72) were presented with colored real-life objects and were asked to recall the colors using a continuous color wheel. Deviations from study colors were modeled to generate two estimates of color memory: the variability of remembered colors—fidelity—and the probability of forgetting the color. Estimating model parameters using both maximum-likelihood estimation and Bayesian hierarchical modeling, we found that working memory had better fidelity than long-term memory (Experiments 1 and 2). Furthermore, within each system, fidelity worsened as a function of time-correlated mechanisms (Experiments 2 and 3). We conclude that fidelity is subject to decline across and within memory systems. Thus, the justification for a general fidelity constraint in memory does not seem to be valid.


2015 ◽  
Vol 26 (3) ◽  
pp. 1176-1186 ◽  
Author(s):  
T. P. Zanto ◽  
W. C. Clapp ◽  
M. T. Rubens ◽  
J. Karlsson ◽  
A. Gazzaley

2020 ◽  
Author(s):  
Timothy F. Brady ◽  
Viola S. Störmer ◽  
George Alvarez

Visual working memory is the cognitive system that holds visual information active to make it resistant to interference from new perceptual input. Information about simple stimuli – colors, orientations – is encoded into working memory rapidly: in under 100ms, working memory ‘fills up’, revealing a stark capacity limit. However, for real-world objects, the same behavioral limits do not hold: with increasing encoding time, people store more real-world objects and do so with more detail. This boost in performance for real-world objects is generally assumed to reflect the use of a separate episodic long-term memory system, rather than working memory. Here we show that this behavioral increase in capacity with real-world objects is not solely due to the use of separate episodic long-term memory systems. In particular, we show that this increase is a result of active storage in working memory, as shown by directly measuring neural activity during the delay period of a working memory task using EEG. These data challenge fixed capacity working memory models, and demonstrate that working memory and its capacity limitations are dependent upon our existing knowledge.


2020 ◽  
pp. 235-281
Author(s):  
Randi C. Martin ◽  
Brenda Rapp ◽  
Jeremy Purcell

The domain-specific approach to working memory assumes specialized working memory systems dedicated to maintaining different types of information (e.g. orthographic, phonological, semantic, visuospatial) which serve to support processing in that domain. These storage systems are assumed to be separate from long-term memory representations in each domain and also from attentional and cognitive control processes. This chapter provides an overview of support for this approach drawn mainly from neuropsychological case study and case series approaches, though it also integrates findings from behavioural and imaging studies of healthy individuals that were motivated by the neuropsychological findings or provide confirmation of those findings. The neuropsychological findings not only demonstrate dissociations between working memory in different domains but also provide a rich source of evidence to address the nature of forgetting in working memory, the interactions between working memory and long-term memory, and the role of aspects of working memory in language comprehension and production.


2021 ◽  
Author(s):  
Julia Krasnoff ◽  
Alessandra S. Souza

Making accurate predictions of future memory performance (Judgements of Learning; JOLs) is a prerequisite for efficient learning. Since decades, those JOLs are assumed to be made inferentially, based on cues. This cue-utilization approach substituted the idea that JOLs are directly linked to memory quality. We criticize the reasons for the rejection of this memory-strength hypothesis because they ignore the existence of two different memory systems: working memory which holds representations immediately accessible, and long-term memory which is a more permanent store. Considering both memory systems, the current work revisited the memory-strength hypothesis: In Experiment 1, participants memorized sequences of two or four colored objects, then they provided JOLs for a long-term memory test, and performed a working memory test on the objects’ colors. After learning 200 objects, the long-term memory test on all studied objects followed. Sequence-length affected working memory, but not long-term memory performance. JOLs, however, were higher for sequences of two than four and correlated higher with working memory than long-term memory performance. Experiment 2 replicated the sequence-length effect on JOLs in the absence of a working memory test. Results of a sequence-eight condition revealed an increase in JOLs’ accuracy when the number of studied objects exceeded working memory span. Contrary to predominant theories, our findings suggest that JOLs are based on the quality of memory representations.


2016 ◽  
Vol 113 (27) ◽  
pp. 7459-7464 ◽  
Author(s):  
Timothy F. Brady ◽  
Viola S. Störmer ◽  
George A. Alvarez

Visual working memory is the cognitive system that holds visual information active to make it resistant to interference from new perceptual input. Information about simple stimuli—colors and orientations—is encoded into working memory rapidly: In under 100 ms, working memory ‟fills up,” revealing a stark capacity limit. However, for real-world objects, the same behavioral limits do not hold: With increasing encoding time, people store more real-world objects and do so with more detail. This boost in performance for real-world objects is generally assumed to reflect the use of a separate episodic long-term memory system, rather than working memory. Here we show that this behavioral increase in capacity with real-world objects is not solely due to the use of separate episodic long-term memory systems. In particular, we show that this increase is a result of active storage in working memory, as shown by directly measuring neural activity during the delay period of a working memory task using EEG. These data challenge fixed-capacity working memory models and demonstrate that working memory and its capacity limitations are dependent upon our existing knowledge.


2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.


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