scholarly journals Is working memory inherently more ‘precise’ than long-term memory? Extremely high fidelity visual long-term memories for frequently encountered objects

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.

2020 ◽  
pp. 311-332
Author(s):  
Nicole Hakim ◽  
Edward Awh ◽  
Edward K. Vogel

Visual working memory allows us to maintain information in mind for use in ongoing cognition. Research on visual working memory often characterizes it within the context of its interaction with long-term memory (LTM). These embedded-processes models describe memory representations as existing in three potential states: inactivated LTM, including all representations stored in LTM; activated LTM, latent representations that can quickly be brought into an active state due to contextual priming or recency; and the focus of attention, an active but sharply limited state in which only a small number of items can be represented simultaneously. This chapter extends the embedded-processes framework of working memory. It proposes that working memory should be defined operationally based on neural activity. By defining working memory in this way, the important theoretical distinction between working memory and LTM is maintained, while still acknowledging that they operate together. It is additionally proposed that active working memory should be further subdivided into at least two subcomponent processes that index item-based storage and currently prioritized spatial locations. This fractionation of working memory is based on recent research that has found that the maintenance of information distinctly relies on item-based representations as well as prioritization of spatial locations. It is hoped that this updated framework of the definition of working memory within the embedded-processes model provides further traction for understanding how we maintain information in mind.


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.


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.


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