scholarly journals Maintenance of relational information in working memory leads to suppression of the sensory cortex

2014 ◽  
Vol 112 (8) ◽  
pp. 1903-1915 ◽  
Author(s):  
Akiko Ikkai ◽  
Kara J. Blacker ◽  
Balaji M. Lakshmanan ◽  
Joshua B. Ewen ◽  
Susan M. Courtney
Keyword(s):  
Working Memory ◽  
Sensory Information ◽  
Alpha Power ◽  
Relational Information ◽  
Visual Hemifield ◽  
Spatial Coordinates ◽  
Eeg Alpha ◽  
Task Irrelevant ◽  
Electroencephalogram Eeg ◽  
Posterior Electrode

Working memory (WM) for sensory-based information about individual objects and their locations appears to involve interactions between lateral prefrontal and sensory cortexes. The mechanisms and representations for maintenance of more abstract, nonsensory information in WM are unknown, particularly whether such actively maintained information can become independent of the sensory information from which it was derived. Previous studies of WM for individual visual items found increased electroencephalogram (EEG) alpha (8–13 Hz) power over posterior electrode sites, which appears to correspond to the suppression of cortical areas that represent irrelevant sensory information. Here, we recorded EEG while participants performed a visual WM task that involved maintaining either concrete spatial coordinates or abstract relational information. Maintenance of relational information resulted in higher alpha power in posterior electrodes. Furthermore, lateralization of alpha power due to a covert shift of attention to one visual hemifield was marginally weaker during storage of relational information than during storage of concrete information. These results suggest that abstract relational information is maintained in WM differently from concrete, sensory representations and that during maintenance of abstract information, posterior sensory regions become task irrelevant and are thus suppressed.

scholarly journals Neurophysiological indicators of internal attention: An EEG-eye-tracking co-registration study [preprint]

2020 ◽  
Author(s):  
Simon Ceh ◽  
Sonja Annerer-Walcher ◽  
Christof Körner ◽  
Christian Rominger ◽  
Silivia E. Kober ◽  
...  
Keyword(s):  
Eye Tracking ◽  
Sensory Information ◽  
Alpha Activity ◽  
Alpha Power ◽  
Gating Mechanism ◽  
Eeg Alpha ◽  
Eeg Alpha Activity ◽  
Task Irrelevant ◽  
Attention Demands ◽  
Internal Attention

Many goal-directed, as well as spontaneous everyday activities (e.g., planning, mind wandering) rely on an internal focus of attention. In this EEG-eye-tracking co-registration study, we investigated effects of attention direction on EEG alpha activity and various relevant eye parameters. We used an established paradigm to manipulate internal attention demands within tasks by means of conditional stimulus masking. Consistent with previous research, IDC involved relatively higher EEG alpha activity (lower alpha desynchronization) at posterior cortical sites. Moreover, IDC was characterized by greater pupil diameter (PD) and PD variance, more and longer blinks, and fewer microsaccades, fixations and saccades. These findings show that internal versus external cognition is associated with robust differences in several neurophysiological indicators that contribute to suppress task-irrelevant information processing at the neural and perceptual level. In a second line of analysis, we explored the intrinsic temporal covariation between EEG alpha activity and eye parameters during rest. This analysis revealed a positive correlation of EEG alpha power with PD especially in bilateral parieto-occipital regions. Together, these findings suggest that EEG alpha activity and PD represent time-sensitive indicators of internal attention demands and are part of a neurophysiological gating mechanism to shield internal cognition from irrelevant sensory information.

scholarly journals The effect of visual salience on memory-based choices

2014 ◽  
Vol 111 (3) ◽  
pp. 481-487 ◽  
Author(s):  
Arezoo Pooresmaeili ◽  
Dominik R. Bach ◽  
Raymond J. Dolan
Keyword(s):  
Working Memory ◽  
Sensory Information ◽  
Relevant Information ◽  
Visual Selective Attention ◽  
Visual Salience ◽  
Perceptual Decision Making ◽  
Capacity Limitations ◽  
Course Of Action ◽  
Task Irrelevant

Deciding whether a stimulus is the “same” or “different” from a previous presented one involves integrating among the incoming sensory information, working memory, and perceptual decision making. Visual selective attention plays a crucial role in selecting the relevant information that informs a subsequent course of action. Previous studies have mainly investigated the role of visual attention during the encoding phase of working memory tasks. In this study, we investigate whether manipulation of bottom-up attention by changing stimulus visual salience impacts on later stages of memory-based decisions. In two experiments, we asked subjects to identify whether a stimulus had either the same or a different feature to that of a memorized sample. We manipulated visual salience of the test stimuli by varying a task-irrelevant feature contrast. Subjects chose a visually salient item more often when they looked for matching features and less often so when they looked for a nonmatch. This pattern of results indicates that salient items are more likely to be identified as a match. We interpret the findings in terms of capacity limitations at a comparison stage where a visually salient item is more likely to exhaust resources leading it to be prematurely parsed as a match.

scholarly journals Perturbing Neural Representations of Working Memory with Task-irrelevant Interruption

2020 ◽  
Vol 32 (3) ◽  
pp. 558-569 ◽  
Author(s):  
Nicole Hakim ◽  
Tobias Feldmann-Wüstefeld ◽  
Edward Awh ◽  
Edward K. Vogel
Keyword(s):  
Working Memory ◽  
Memory Task ◽  
Relevant Information ◽  
Alpha Power ◽  
Neural Signals ◽  
Neural Representations ◽  
Contralateral Delay Activity ◽  
The Face ◽  
Task Irrelevant ◽  
The Impact

Working memory maintains information so that it can be used in complex cognitive tasks. A key challenge for this system is to maintain relevant information in the face of task-irrelevant perturbations. Across two experiments, we investigated the impact of task-irrelevant interruptions on neural representations of working memory. We recorded EEG activity in humans while they performed a working memory task. On a subset of trials, we interrupted participants with salient but task-irrelevant objects. To track the impact of these task-irrelevant interruptions on neural representations of working memory, we measured two well-characterized, temporally sensitive EEG markers that reflect active, prioritized working memory representations: the contralateral delay activity and lateralized alpha power (8–12 Hz). After interruption, we found that contralateral delay activity amplitude momentarily sustained but was gone by the end of the trial. Lateralized alpha power was immediately influenced by the interrupters but recovered by the end of the trial. This suggests that dissociable neural processes contribute to the maintenance of working memory information and that brief irrelevant onsets disrupt two distinct online aspects of working memory. In addition, we found that task expectancy modulated the timing and magnitude of how these two neural signals responded to task-irrelevant interruptions, suggesting that the brain's response to task-irrelevant interruption is shaped by task context.

Impact of Experimental Modulation of EEG Alpha Power on Visual Working Memory Storage in Healthy Participants

2020 ◽  
Vol 87 (9) ◽  
pp. S403 ◽  
Author(s):  
Molly Erickson ◽  
Dillon Smith ◽  
Laura Crespo ◽  
Steven Silverstein
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Memory Storage ◽  
Alpha Power ◽  
Eeg Alpha ◽  
Healthy Participants

scholarly journals Working Memory Capacity Is Negatively Associated with Memory Load Modulation of Alpha Oscillations in Retention of Verbal Working Memory

2019 ◽  
Vol 31 (12) ◽  
pp. 1933-1945 ◽  
Author(s):  
Zhenhong Hu ◽  
Christopher M. Barkley ◽  
Susan E. Marino ◽  
Chao Wang ◽  
Abhijit Rajan ◽  
...  
Keyword(s):  
Working Memory ◽  
Memory Load ◽  
Working Memory Capacity ◽  
Verbal Working Memory ◽  
Memory Capacity ◽  
Alpha Power ◽  
Alpha Oscillations ◽  
Load Modulation ◽  
Task Irrelevant ◽  
With Memory

Working memory capacity (WMC) measures the amount of information that can be maintained online in the face of distraction. Past work has shown that the efficiency with which the frontostriatal circuit filters out task-irrelevant distracting information is positively correlated with WMC. Recent work has demonstrated a role of posterior alpha oscillations (8–13 Hz) in providing a sensory gating mechanism. We investigated the relationship between memory load modulation of alpha power and WMC in two verbal working memory experiments. In both experiments, we found that posterior alpha power increased with memory load during memory, in agreement with previous reports. Across individuals, the degree of alpha power modulation by memory load was negatively associated with WMC, namely, the higher the WMC, the less alpha power was modulated by memory load. After the administration of topiramate, a drug known to affect alpha oscillations and have a negative impact on working memory function, the negative correlation between memory load modulation of alpha power and WMC was no longer statistically significant but still somewhat detectable. These results suggest that (1) individuals with low WMC demonstrate stronger alpha power modulation by memory load, reflecting possibly an increased reliance on sensory gating to suppress task-irrelevant information in these individuals, in contrast to their high WMC counterparts who rely more on frontal areas to perform this function and (2) this negative association between memory load modulation of alpha oscillations and WMC is vulnerable to drug-related cognitive disruption.

scholarly journals EEG alpha and theta signatures of socially and non-socially cued working memory in virtual reality

2021 ◽  
Author(s):  
Samantha Gregory ◽  
Hongfang Wang ◽  
Klaus Kessler
Keyword(s):  
Working Memory ◽  
Virtual Reality ◽  
Memory Performance ◽  
Social Cues ◽  
Neural Mechanisms ◽  
Alpha Power ◽  
Theta Power ◽  
Social Cue ◽  
The Social ◽  
Eeg Alpha

In this preregistered study (https://osf.io/s4rm9) we investigated the behavioural and neurological (EEG; alpha and theta) effects of dynamic non-predictive social and non-social cues on working memory. In a virtual environment realistic human-avatars initiated eye contact before dynamically looking to the left or right side of a table. A moving stick served as a non-social control cue. Kitchen items were presented in the valid cued or invalid un-cued location for encoding. Behavioural findings show a similar influence of the social and non-social cues on working memory performance. Alpha power changes were equivalent for the social and non-social cues during cuing and encoding. However, theta power changes revealed different patterns for the two cues. Theta power increased more strongly for the non-social cue compared to the social cue during initial cuing. Further, while for the non-social cue there was a significantly larger increase in theta power for valid compared to invalid conditions during encoding, this was reversed for the social cue, with a significantly larger increase in theta power in posterior electrodes for the invalid compared to valid conditions. Therefore, while social and non-social attention cues impact working memory performance in a similar fashion, the underlying neural mechanisms appear to differ.

scholarly journals Electroencephalogram (EEG) Alpha Power as a Marker of Visuospatial Attention Orienting and Suppression in Normoxia and Hypoxia. An Exploratory Study

2020 ◽  
Vol 10 (3) ◽  
pp. 140 ◽  
Author(s):  
Alberto Zani ◽  
Clara Tumminelli ◽  
Alice Mado Proverbio
Keyword(s):  
Exploratory Study ◽  
Visuospatial Attention ◽  
Alpha Power ◽  
Control Networks ◽  
Attention Orienting ◽  
Oxygenation Condition ◽  
Eeg Alpha ◽  
The Right ◽  
And Control ◽  
Electroencephalogram Eeg

While electroencephalogram (EEG) alpha desynchronization has been related to anticipatory orienting of visuospatial attention, an increase in alpha power has been associated to its inhibition. A separate line of findings indicated that alpha is affected by a deficient oxygenation of the brain or hypoxia, although leaving unclear whether the latter increases or decreases alpha synchronization. Here, we carried out an exploratory study on these issues by monitoring attention alerting, orienting, and control networks functionality by means of EEG recorded both in normoxia and hypoxia in college students engaged in four attentional cue-target conditions induced by a redesigned Attention Network Test. Alpha power was computed through Fast Fourier Transform. Regardless of brain oxygenation condition, alpha desynchronization was the highest during exogenous, uncued orienting of spatial attention, the lowest during alerting but spatially unpredictable, cued exogenous orienting of attention, and of intermediate level during validly cued endogenous orienting of attention, no matter the motor response workload demanded by the latter, especially over the left hemisphere. Hypoxia induced an increase in alpha power over the right-sided occipital and parietal scalp areas independent of attention cueing and conflict conditions. All in all, these findings prove that attention orienting is undergirded by alpha desynchronization and that alpha right-sided synchronization in hypoxia might sub-serve either the effort to sustain attention over time or an overall suppression of attention networks functionality.

scholarly journals Perturbing neural representations of working memory with task-irrelevant interruption

2019 ◽  
Author(s):  
Nicole Hakim ◽  
Tobias Feldmann-Wüstefeld ◽  
Edward Awh ◽  
Edward K. Vogel
Keyword(s):  
Working Memory ◽  
Memory Task ◽  
Relevant Information ◽  
Cognitive Tasks ◽  
Alpha Power ◽  
Task Context ◽  
Neural Representations ◽  
Task Irrelevant ◽  
The Impact ◽  
Neural Signatures

AbstractWorking memory maintains information so that it can be used in complex cognitive tasks. A key challenge for this system is to maintain relevant information in the face of task-irrelevant perturbations. In this series of experiments, we investigated the impact of task-irrelevant interruptions on neural representations of working memory. We recorded electroencephalogram (EEG) activity in humans while they performed a working memory task. On a subset of trials, we interrupted participants with salient, but task-irrelevant objects. To track the impact of these task-irrelevant interruptions on neural representations of working memory, we measured two well-characterized, temporally sensitive EEG markers that reflect active, prioritized working memory representations: the contralateral delay activity (CDA) and lateralized alpha power (8-12hz). Following interruption, we found that CDA momentarily sustained, but was gone by the end of the trial. Lateralized alpha power was immediately influenced by the interrupters, but recovered by the end of the trial. This suggests that dissociable neural processes contribute to the maintenance of working memory information. Additionally, we found that task expectancy modulated the timing and magnitude of how these two neural signals responded to task-irrelevant interruptions, suggesting that the brain’s response to task-irrelevant interruption is shaped by task context. The distinct time courses of and influence of task context on these two neural signatures of working memory have many interesting theoretical implications about how information is actively maintained in working memory.Significance statementWorking memory plays a central role in intelligent behaviors because it actively maintains relevant information that is easily accessible and manipulatable. In everyday life, we are often interrupted while performing such complex cognitive tasks. Therefore, understanding how working memory responds to and overcomes momentary task-irrelevant interruptions is critical for us to understand how complex cognition works. Here, we unveil how two distinct neural signatures of working memory respond to task-irrelevant interruptions by recording electroencephalogram activity in humans. Our findings raise long-standing theoretical questions about how different neural and cognitive processes contribute to the maintenance of information in working memory.

scholarly journals The role of alpha power in the suppression of anticipated distractors during verbal working memory

2020 ◽  
Author(s):  
Sabrina Sghirripa ◽  
Lynton Graetz ◽  
Ashley Merkin ◽  
Nigel C Rogasch ◽  
Michael C Ridding ◽  
...  
Keyword(s):  
Working Memory ◽  
Reaction Times ◽  
Verbal Working Memory ◽  
Relevant Information ◽  
Neural Oscillations ◽  
Alpha Power ◽  
Alpha Frequency ◽  
Task Irrelevant ◽  
Sternberg Task

AbstractAs working memory (WM) is limited in capacity, it is important to direct neural resources towards processing task-relevant information while ignoring distractors. Neural oscillations in the alpha frequency band (8-12 Hz) have been suggested to play a role in the inhibition of task-irrelevant information during WM, although results are mixed, possibly due to differences in the type of WM task employed. Here, we examined the role of alpha power in inhibition of anticipated distractors of varying strength using a modified Sternberg task where the encoding and retention periods were temporally separated. We recorded EEG while 20 young adults completed the task and found: 1) slower reaction times in strong distractor trials compared to weak distractor trials; 2) increased alpha power in posterior regions from baseline prior to presentation of a distractor regardless of condition; and 3) no differences in alpha power between strong and weak distractor conditions. Our results suggest that parieto-occipital alpha power is increased prior to a distractor. However we could not find evidence that alpha power is further modulated by distractor strength.

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