scholarly journals Prefrontal Lesions Disrupt Posterior Alpha–Gamma Coordination of Visual Working Memory Representations

2021 ◽  
pp. 1-13
Author(s):  
Saeideh Davoudi ◽  
Mohsen Parto Dezfouli ◽  
Robert T. Knight ◽  
Mohammad Reza Daliri ◽  
Elizabeth L. Johnson
Keyword(s):  
Working Memory ◽  
Feature Selection ◽  
Visual Representations ◽  
Temporal Position ◽  
Memory Representations ◽  
Frequency Coupling ◽  
Oscillatory Mechanisms ◽  
Cross Frequency Coupling ◽  
Selection Of

Abstract How does the human brain prioritize different visual representations in working memory (WM)? Here, we define the oscillatory mechanisms supporting selection of “where” and “when” features from visual WM storage and investigate the role of pFC in feature selection. Fourteen individuals with lateral pFC damage and 20 healthy controls performed a visuospatial WM task while EEG was recorded. On each trial, two shapes were presented sequentially in a top/bottom spatial orientation. A retro-cue presented mid-delay prompted which of the two shapes had been in either the top/bottom spatial position or first/second temporal position. We found that cross-frequency coupling between parieto-occipital alpha (α; 8–12 Hz) oscillations and topographically distributed gamma (γ; 30–50 Hz) activity tracked selection of the distinct cued feature in controls. This signature of feature selection was disrupted in patients with pFC lesions, despite intact α–γ coupling independent of feature selection. These findings reveal a pFC-dependent parieto-occipital α–γ mechanism for the rapid selection of visual WM representations.

scholarly journals Working Memory and Cross-Frequency Coupling of Neuronal Oscillations

2021 ◽  
Vol 12 ◽  
Author(s):  
Mohammed Abubaker ◽  
Wiam Al Qasem ◽  
Eugen Kvašňák
Keyword(s):  
Working Memory ◽  
Cognitive Impairment ◽  
Brain Stimulation ◽  
Large Body ◽  
Cognitive Outcomes ◽  
Essential Component ◽  
Non Invasive ◽  
Transcranial Alternating Current Stimulation ◽  
Frequency Coupling ◽  
Cross Frequency Coupling

Working memory (WM) is the active retention and processing of information over a few seconds and is considered an essential component of cognitive function. The reduced WM capacity is a common feature in many diseases, such as schizophrenia, attention deficit hyperactivity disorder (ADHD), mild cognitive impairment (MCI), and Alzheimer's disease (AD). The theta-gamma neural code is an essential component of memory representations in the multi-item WM. A large body of studies have examined the association between cross-frequency coupling (CFC) across the cerebral cortices and WM performance; electrophysiological data together with the behavioral results showed the associations between CFC and WM performance. The oscillatory entrainment (sensory, non-invasive electrical/magnetic, and invasive electrical) remains the key method to investigate the causal relationship between CFC and WM. The frequency-tuned non-invasive brain stimulation is a promising way to improve WM performance in healthy and non-healthy patients with cognitive impairment. The WM performance is sensitive to the phase and rhythm of externally applied stimulations. CFC-transcranial-alternating current stimulation (CFC-tACS) is a recent approach in neuroscience that could alter cognitive outcomes. The studies that investigated (1) the association between CFC and WM and (2) the brain stimulation protocols that enhanced WM through modulating CFC by the means of the non-invasive brain stimulation techniques have been included in this review. In principle, this review can guide the researchers to identify the most prominent form of CFC associated with WM processing (e.g., theta/gamma phase-amplitude coupling), and to define the previously published studies that manipulate endogenous CFC externally to improve WM. This in turn will pave the path for future studies aimed at investigating the CFC-tACS effect on WM. The CFC-tACS protocols need to be thoroughly studied before they can be considered as therapeutic tools in patients with WM deficits.

scholarly journals Goal-directed and stimulus-driven selection of internal representations

2020 ◽  
Vol 117 (39) ◽  
pp. 24590-24598
Author(s):  
Freek van Ede ◽  
Alexander G. Board ◽  
Anna C. Nobre
Keyword(s):  
Working Memory ◽  
Feature Matching ◽  
Memory Performance ◽  
Sensory Information ◽  
Internal Representations ◽  
Memory Representations ◽  
External Stimuli ◽  
Selection Of ◽  
Do So

Adaptive behavior relies on the selection of relevant sensory information from both the external environment and internal memory representations. In understanding external selection, a classic distinction is made between voluntary (goal-directed) and involuntary (stimulus-driven) guidance of attention. We have developed a task—the anti-retrocue task—to separate and examine voluntary and involuntary guidance of attention to internal representations in visual working memory. We show that both voluntary and involuntary factors influence memory performance but do so in distinct ways. Moreover, by tracking gaze biases linked to attentional focusing in memory, we provide direct evidence for an involuntary “retro-capture” effect whereby external stimuli involuntarily trigger the selection of feature-matching internal representations. We show that stimulus-driven and goal-directed influences compete for selection in memory, and that the balance of this competition—as reflected in oculomotor signatures of internal attention—predicts the quality of ensuing memory-guided behavior. Thus, goal-directed and stimulus-driven factors together determine the fate not only of perception, but also of internal representations in working memory.

scholarly journals Cross-frequency coupling supports multi-item working memory in the human hippocampus

2010 ◽  
Vol 107 (7) ◽  
pp. 3228-3233 ◽  
Author(s):  
N. Axmacher ◽  
M. M. Henseler ◽  
O. Jensen ◽  
I. Weinreich ◽  
C. E. Elger ◽  
...  
Keyword(s):  
Working Memory ◽  
Human Hippocampus ◽  
Frequency Coupling ◽  
Cross Frequency Coupling

scholarly journals Target-Target Perceptual Similarity Within the Attentional Blink

2020 ◽  
Vol 11 ◽  
Author(s):  
Ivan M. Makarov ◽  
Elena S. Gorbunova
Keyword(s):  
Working Memory ◽  
Attentional Blink ◽  
Trial Design ◽  
Visual Presentation ◽  
Perceptual Similarity ◽  
Memory Representations ◽  
Report Accuracy ◽  
Blocked Design ◽  
Shape And Size

Three experiments investigated the role of target-target perceptual similarity within the attentional blink (AB). Various geometric shapes were presented in a rapid serial visual presentation task. Targets could have 2, 1, or 0 shared features. Features included shape and size. The second target was presented after five or six different lags after the first target. The task was to detect both targets on each trial. Second-target report accuracy was increased by target-target similarity. This modulation was observed more for mixed-trial design as compared with blocked design. Results are discussed in terms of increased stability of working memory representations and reduced interference for second-target processing.

Neglecting the posterior parietal cortex: The role of higher-order perceptual memories for working-memory retention

2003 ◽  
Vol 26 (6) ◽  
pp. 749-749 ◽  
Author(s):  
Axel Mecklinger ◽  
Bertram Opitz
Keyword(s):  
Working Memory ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Higher Order ◽  
Fmri Data ◽  
Memory Retention ◽  
Memory Representations ◽  
Posterior Parietal ◽  
Dynamic Link

The view that posterior brain systems engaged in lower-order perceptual functions are activated during sustained retention is challenged by fMRI data, which show consistent retention-related activation of higher-order memory representations for a variety of working-memory materials. Sustained retention entails the dynamic link of these higher-order memories with schemata for goal-oriented action housed by the frontal lobes.

The contribution of long-term memory and the role of frontal-lobe systems in on-line processing

2003 ◽  
Vol 26 (6) ◽  
pp. 756-756 ◽  
Author(s):  
Jennifer D. Ryan ◽  
Neal J. Cohen
Keyword(s):  
Working Memory ◽  
Frontal Lobe ◽  
Pivotal Role ◽  
Long Term Memory ◽  
Term Memory ◽  
Memory Binding ◽  
Memory Representations ◽  
On Line

Ruchkin et al. ascribe a pivotal role to long-term memory representations and binding within working memory. Here we focus on the interaction of working memory and long-term memory in supporting on-line representations of experience available to guide on-going processing, and we distinguish the role of frontal-lobe systems from what the hippocampus contributes to relational long-term memory binding.

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