A Cortical Mechanism for Binding in Visual Working Memory

2001 ◽  
Vol 13 (6) ◽  
pp. 766-785 ◽  
Author(s):  
Antonino Raffone ◽  
Gezinus Wolters
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Phase Segregation ◽  
Verbal Working Memory ◽  
Long Term Memory ◽  
Limited Capacity ◽  
Multiple Features ◽  
Single Pattern ◽  
Individual Features

Luck and Vogel (1997) showed that the storage capacity of visual working memory is about four objects and that this capacity does not depend on the number of features making up the objects. Thus, visual working memory seems to process integrated objects rather than individual features, just as verbal working memory handles higher-order “chunks” instead of individual features or letters. In this article, we present a model based on synchronization and desynchronization of reverberatory neural assemblies, which can parsimoniously account for both the limited capacity of visual working memory, and for the temporary binding of multiple assemblies into a single pattern. A critical capacity of about three to four independent patterns showed up in our simulations, consistent with the results of Luck and Vogel. The same desynchronizing mechanism optimizing phase segregation between assemblies coding for separate features or multifeature objects poses a limit to the number of oscillatory reverberations. We show how retention of multiple features as visual chunks (feature conjunctions or objects) in terms of synchronized reverberatory assemblies may be achieved with and without long-term memory guidance.

Manifold Visual Working Memory

2020 ◽  
pp. 311-332
Author(s):  
Nicole Hakim ◽  
Edward Awh ◽  
Edward K. Vogel
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Neural Activity ◽  
Long Term Memory ◽  
Term Memory ◽  
Memory Representations ◽  
Latent Representations ◽  
Definition Of ◽  
Spatial Locations

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.

Input to Verbal Working Memory

2004 ◽  
Vol 51 (4) ◽  
pp. 231-239 ◽  
Author(s):  
Thomas Jacobsen ◽  
Erich Schröger
Keyword(s):  
Working Memory ◽  
Speech Sound ◽  
Verbal Working Memory ◽  
Relevant Information ◽  
Event Related Potential ◽  
Long Term Memory ◽  
Auditory Sensory Memory ◽  
Complex Tones ◽  
Informational Basis

Abstract. Working memory uses central sound representations as an informational basis. The central sound representation is the temporally and feature-integrated mental representation that corresponds to phenomenal perception. It is used in (higher-order) mental operations and stored in long-term memory. In the bottom-up processing path, the central sound representation can be probed at the level of auditory sensory memory with the mismatch negativity (MMN) of the event-related potential. The present paper reviews a newly developed MMN paradigm to tap into the processing of speech sound representations. Preattentive vowel categorization based on F1-F2 formant information occurs in speech sounds and complex tones even under conditions of high variability of the auditory input. However, an additional experiment demonstrated the limits of the preattentive categorization of language-relevant information. It tested whether the system categorizes complex tones containing the F1 and F2 formant components of the vowel /a/ differently than six sounds with nonlanguage-like F1-F2 combinations. From the absence of an MMN in this experiment, it is concluded that no adequate vowel representation was constructed. This shows limitations of the capability of preattentive vowel categorization.

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
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Memory ◽  
Memory Systems ◽  
Long Term Memory ◽  
Continuous Measure ◽  
High Fidelity ◽  
Term Memory ◽  
Naturalistic Setting

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.

Dispelling the magic: Towards memory without capacity

2001 ◽  
Vol 24 (1) ◽  
pp. 147-148 ◽  
Author(s):  
Niels A. Taatgen
Keyword(s):  
Working Memory ◽  
General Theory ◽  
Storage Capacity ◽  
Long Term Memory ◽  
Limited Capacity ◽  
Memory Research ◽  
Term Memory ◽  
Capacity Limitations ◽  
The Right

The limited capacity for unrelated things is a fact that needs to be explained by a general theory of memory, rather than being itself used as a means of explaining data. A pure storage capacity is therefore not the right assumption for memory research. Instead an explanation is needed of how capacity limitations arise from the interaction between the environment and the cognitive system. The ACT-R architecture, a theory without working memory but a long-term memory based on activation, may provide such an explanation.

Dynamic Visual Noise Interferes with Storage in Visual Working Memory

2008 ◽  
Vol 55 (4) ◽  
pp. 283-289 ◽  
Author(s):  
Graham M. Dean ◽  
Stephen A. Dewhurst ◽  
Annalise Whittaker
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Noise ◽  
Long Term Memory ◽  
Dynamic Visual Noise ◽  
Long Term Storage ◽  
With Memory ◽  
Term Storage ◽  
Different Levels

Several studies have demonstrated that dynamic visual noise (DVN) does not interfere with memory for random matrices. This has led to suggestions that (a) visual working memory is distinct from imagery, and (b) visual working memory is not a gateway between sensory input and long-term storage. A comparison of the interference effects of DVN with memory for matrices and colored textures shows that DVN can interfere with visual working memory, probably at a level of visual detail not easily supported by long-term memory structures or the recoding of the visual pattern elements. The results support a gateway model of visuospatial working memory and raise questions about the most appropriate ways to measure and model the different levels of representation of information that can be held in visual working memory.

Sign in / Sign up

Export Citation Format

Share Document