scholarly journals Load-Dependent Increases in Delay-Period Alpha-Band Power Track the Gating of Task-Irrelevant Inputs to Working Memory

2017 ◽  
Vol 11 ◽  
Author(s):  
Andrew J. Heinz ◽  
Jeffrey S. Johnson
Keyword(s):  
Working Memory ◽  
Delay Period ◽  
Alpha Band ◽  
Band Power ◽  
Task Irrelevant

scholarly journals Salient distractors open the door of perception: alpha desynchronization marks sensory gating in a working memory task

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zsuzsanna Fodor ◽  
Csilla Marosi ◽  
László Tombor ◽  
Gábor Csukly
Keyword(s):  
Working Memory ◽  
Memory Task ◽  
Relevant Information ◽  
Alpha Band ◽  
Theta Band ◽  
Retention Period ◽  
Alpha Frequency ◽  
Task Irrelevant ◽  
Spectral Perturbation ◽  
Distractor Rejection

Abstract Focusing attention on relevant information while ignoring distracting stimuli is essential to the efficacy of working memory. Alpha- and theta-band oscillations have been linked to the inhibition of anticipated and attentionally avoidable distractors. However, the neurophysiological background of the rejection of task-irrelevant stimuli appearing in the focus of attention is not fully understood. We aimed to examine whether theta and alpha-band oscillations serve as an indicator of successful distractor rejection. Twenty-four students were enrolled in the study. 64-channel EEG was recorded during a modified Sternberg working memory task where weak and strong (salient) distractors were presented during the retention period. Event-related spectral perturbation in the alpha frequency band was significantly modulated by the saliency of the distracting stimuli, while theta oscillation was modulated by the need for cognitive control. Moreover, stronger alpha desynchronization to strong relative to weak distracting stimuli significantly increased the probability of mistakenly identifying the presented distractor as a member of the memory sequence. Therefore, our results suggest that alpha activity reflects the vulnerability of attention to distracting salient stimuli.

scholarly journals Spatial working memory representations in human cortex are robust to a task-irrelevant interrupting stimulus

2021 ◽  
Author(s):  
Kelvin Vu-Cheung ◽  
Edward F Ester ◽  
Thomas C Sprague
Keyword(s):  
Working Memory ◽  
Visual Information ◽  
Spatial Working Memory ◽  
Delay Period ◽  
Visual Signals ◽  
Reconstruction Technique ◽  
Behavioral Performance ◽  
Visual Responses ◽  
The Individual ◽  
Task Irrelevant

Visual working memory (WM) enables the maintenance and manipulation of information no longer accessible in the visual world. Previous research has identified spatial WM representations in activation patterns in visual, parietal, and frontal cortex. In natural vision, the period between the encoding of information into WM and the time when it is used to guide behavior (the delay period) is rarely "empty", as is the case in most of the above laboratory experiments. In naturalistic conditions, eye movements, movement of the individual, and events in the environment result in visual signals which may overwrite or impair the fidelity of WM representations, especially in early sensory cortices. Here, we evaluated the extent to which a brief, irrelevant interrupting visual stimulus presented during a spatial WM delay period impaired behavioral performance and WM representation fidelity assayed using an image reconstruction technique (inverted encoding model). On each trial, participants (both sexes) viewed two target dots and were immediately post-cued to remember the precise spatial position of one dot. On 50% of trials, a brief interrupter stimulus appeared. While we observed strong transient univariate visual responses to the distracter stimulus, we saw no change in reconstructed neural WM representations under distraction, nor a change in behavioral performance on a continuous recall task. This suggests that spatial WM representations may be particularly robust to interference from incoming task-irrelevant visual information, perhaps related to their role in guiding movements.

scholarly journals Temporally distinct oscillatory codes of retention and manipulation of verbal working memory

2021 ◽  
Author(s):  
Yuri G. Pavlov ◽  
Boris Kotchoubey
Keyword(s):  
Working Memory ◽  
Short Term Memory ◽  
Spectral Power ◽  
Verbal Working Memory ◽  
Delay Period ◽  
Beta Band ◽  
Short Term ◽  
Term Memory ◽  
Band Power ◽  
The Difference

AbstractMost psychophysiological studies of working memory (WM) target only the short-term memory construct, while short-term memory is only a part of the WM responsible for the storage of sensory information. Much less effort has been devoted to study brain mechanisms supporting the executive components of WM – the part responsible for the manipulation of information. Here, 156 human participants (82 females) performed two tasks requiring either simple retention or retention and manipulation of verbal information in WM. A relatively long delay period (> 6 s) was employed to investigate the temporal trajectory of the oscillatory brain activity using EEG. Compared to baseline, theta activity was significantly enhanced during encoding and the delay period. Alpha-band power decreased during encoding and switched to an increase in the first part of the delay before returning to the baseline in the second part; beta-band power remained below baseline during all three time intervals. The difference between the manipulation and retention tasks in spectral power had diverse temporal trajectories in different frequency bands. The difference maintained over encoding and the first part of the delay in theta, during the first part of the delay in beta, and during the whole delay period in alpha. Our results suggest that task-related modulations in theta power co-vary with the demands on the executive control network; beta suppression during mental manipulation can be related to the activation of motor networks; alpha is likely to reflect the activation of language areas simultaneously with sensory input blockade.

scholarly journals Topography of alpha-band power tracks improvement in working memory precision with repeated encoding

2017 ◽  
Vol 17 (10) ◽  
pp. 333
Author(s):  
Kirsten Adam ◽  
Joshua Foster ◽  
David Sutterer ◽  
Edward Vogel ◽  
Edward Awh
Keyword(s):  
Working Memory ◽  
Alpha Band ◽  
Band Power ◽  
Memory Precision

scholarly journals Event-Related Alpha-Band Power Changes During Self-reflection and Working Memory Tasks in Healthy Individuals

2021 ◽  
Vol 14 ◽  
Author(s):  
Takahiro Matsuoka ◽  
Takaki Shimode ◽  
Toshio Ota ◽  
Koji Matsuo
Keyword(s):  
Working Memory ◽  
Attentional Control ◽  
Healthy Subjects ◽  
Target Stimulus ◽  
Alpha Band ◽  
Healthy Individuals ◽  
Occipital Area ◽  
Self Reflection ◽  
Band Power ◽  
Preliminary Study

Dysfunctional attentional control is observed in patients with mental disorders. However, there is no established neurophysiological method to assess attention in such patients. We showed a discrepancy in alpha-band power in the tasks that evoked internal and external attention event-related alpha-band power changes in healthy subjects during self-reflection (SR) and working memory (WM) tasks in a preliminary study. In this study, we aimed at elucidating event-related alpha-band power changes in healthy subjects during the tasks, addressing the shortcomings of the previous study. Sixteen healthy volunteers were examined for the event-related power (ERpow) change during the tasks. The results demonstrated the discrepancy of alpha-band ERpow at 8, 10, and 12 Hz in the parieto-occipital area between the WM and SR tasks for a period between a target stimulus and a command stimulus, where a participant switched to internal attention from external attention according to the SR task and remained at external attention according to the WM task. The results suggest that alpha-band ERpow in this area is associated with the direction of attention in response to cognitive stimuli, indicating that the findings of ERpow during the two tasks would potentially aid in the clarification of the pathophysiology of the dysfunctional change in attention in patients with psychiatric disorders.

scholarly journals Effects of load and emotional state on EEG alpha-band power and inter-site synchrony during a visual working memory task

2020 ◽  
Vol 20 (5) ◽  
pp. 1122-1132
Author(s):  
Jessica Sanches Braga Figueira ◽  
Isabel de Paula Antunes David ◽  
Isabela Lobo ◽  
Luiza Bonfim Pacheco ◽  
Mirtes Garcia Pereira ◽  
...  
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Emotional State ◽  
Memory Task ◽  
Alpha Band ◽  
Band Power ◽  
Eeg Alpha

scholarly journals The impact of visual gaze direction on auditory object tracking

2017 ◽  
Author(s):  
Ulrich Pomper ◽  
Maria Chait
Keyword(s):  
Subjective Experience ◽  
Response Times ◽  
Auditory Attention ◽  
Alpha Band ◽  
Theta Band ◽  
Selective Listening ◽  
Band Power ◽  
Task Irrelevant ◽  
Visual Gaze ◽  
The Impact

AbstractSubjective experience suggests that we are able to direct our auditory attention independent of our visual gaze, e.g when shadowing a nearby conversation at a cocktail party. But what are the consequences at the behavioural and neural level? While numerous studies have investigated both auditory attention and visual gaze independently, little is known about their interaction during selective listening. In the present EEG study, we manipulated visual gaze independently of auditory attention while participants detected targets presented from one of three loudspeakers. We observed increased response times when gaze was directed away from the locus of auditory attention. Further, we found an increase in occipital alpha-band power contralateral to the direction of gaze, indicative of a suppression of distracting input. Finally, this condition also led to stronger central theta-band power, which correlated with the observed effect in response times, indicative of differences in top-down processing. Our data suggest that a misalignment between gaze and auditory attention both reduce behavioural performance and modulate underlying neural processes. The involvement of central theta-band and occipital alpha-band effects are in line with compensatory neural mechanisms such as increased cognitive control and the suppression of task irrelevant inputs.

scholarly journals Temporal Dynamics of Attention during Encoding versus Maintenance of Working Memory: Complementary Views from Event-related Potentials and Alpha-band Oscillations

2015 ◽  
Vol 27 (3) ◽  
pp. 492-508 ◽  
Author(s):  
Nicholas E. Myers ◽  
Lena Walther ◽  
George Wallis ◽  
Mark G. Stokes ◽  
Anna C. Nobre
Keyword(s):  
Working Memory ◽  
Visual Information ◽  
Temporal Dynamics ◽  
Recall Performance ◽  
Event Related Potentials ◽  
Alpha Band ◽  
Related Potentials ◽  
Frontoparietal Control Network ◽  
Anticipatory Attention ◽  
Processing Differences

Working memory (WM) is strongly influenced by attention. In visual WM tasks, recall performance can be improved by an attention-guiding cue presented before encoding (precue) or during maintenance (retrocue). Although precues and retrocues recruit a similar frontoparietal control network, the two are likely to exhibit some processing differences, because precues invite anticipation of upcoming information whereas retrocues may guide prioritization, protection, and selection of information already in mind. Here we explored the behavioral and electrophysiological differences between precueing and retrocueing in a new visual WM task designed to permit a direct comparison between cueing conditions. We found marked differences in ERP profiles between the precue and retrocue conditions. In line with precues primarily generating an anticipatory shift of attention toward the location of an upcoming item, we found a robust lateralization in late cue-evoked potentials associated with target anticipation. Retrocues elicited a different pattern of ERPs that was compatible with an early selection mechanism, but not with stimulus anticipation. In contrast to the distinct ERP patterns, alpha-band (8–14 Hz) lateralization was indistinguishable between cue types (reflecting, in both conditions, the location of the cued item). We speculate that, whereas alpha-band lateralization after a precue is likely to enable anticipatory attention, lateralization after a retrocue may instead enable the controlled spatiotopic access to recently encoded visual information.

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