scholarly journals Distractor inhibition contributes to retroactive attentional orienting within working memory: Evidence by lateralized alpha oscillations in the EEG

2017 ◽  
Author(s):  
Daniel Schneider ◽  
Anna Barth ◽  
Henrike Haase ◽  
Clayton Hickey ◽  
Edmund Wascher

AbstractShifts of attention within mental representations based on retroactive cues (retro-cues) facilitate performance in working memory tasks. It was suggested that this retro-cue benefit is related to the concentration of working memory resources on a subset of representations, thereby improving storage and retrieval at the cost of non-cued items. However, the attentional mechanisms underlying this updating of working memory representations remain unknown. Here, we present EEG data for distinguishing between target enhancement and distractor suppression processes in the context of retroactive attentional orienting. Therefore, we used a working memory paradigm with retro-cues indicating a shift of attention to either a lateralized or non-lateralized item. There was an increase of posterior alpha power contralateral compared to ipsilateral to the irrelevant item when a non-lateralized mental representation was cued and a contralateral suppression of posterior alpha power when a lateralized item had to be selected. This suggests that both inhibition of the non-cued information and enhancement of the target representation are important features of attentional orienting within working memory. By further presenting cues to either remember or to forget a working memory representation, we give a first impression of these retroactive attentional sub-processes as two separable cognitive mechanisms.

2020 ◽  
Author(s):  
Keisuke Fukuda ◽  
April Emily Pereira ◽  
Joseph M. Saito ◽  
Ty Yi Tang ◽  
Hiroyuki Tsubomi ◽  
...  

Visual information around us is rarely static. To carry out a task in such a dynamic environment, we often have to compare current visual input with our working memory representation of the immediate past. However, little is known about what happens to a working memory (WM) representation when it is compared with perceptual input. Here, we tested university students and found that perceptual comparisons retroactively bias working memory representations toward subjectively-similar perceptual inputs. Furthermore, using computational modeling and individual differences analyses, we found that representational integration between WM representations and perceptually-similar input underlies this similarity-induced memory bias. Together, our findings highlight a novel source of WM distortion and suggest a general mechanism that determines how WM representations interact with new perceptual input.


2020 ◽  
Author(s):  
Xueying Fu ◽  
Chaoxiong Ye ◽  
huzhonghua ◽  
Tengfei Liang ◽  
Ziyuan Li ◽  
...  

Memory performance can be improved by retrospectively cueing an item maintained in visual working memory (VWM). Different hypotheses have been proposed to explain the mechanisms behind retro-cueing and VWM. Previous behavioral studies suggest that different retro-cue validities may lead individuals to implement retro-cues in different ways to obtain a retro-cue effect. However, there is still no clear electroencephalogram (EEG) evidence to support that the retro-cue effect under different validity conditions is triggered by different mechanisms. Herein, we investigated whether retro-cue validity modulated the mechanisms underlying the retro-cue effect in VWM by using EEGs. We manipulated retro-cue validity by using blocks in a color change detection task. Contralateral delay activity (CDA) and lateralized alpha power were used assess spatial attention and memory storage, respectively. Significant retro-cue effects were observed under both high- and low-validity conditions. More importantly, although the retro-cue could redirect spatial attention under both high- and low-validity conditions, we found that participants maintained the non-cued items during a measured time interval under the low-validity condition, but dropped them out of VWM under the high-validity condition. Our results resolve previous contradictory findings. The retro-cue effect in our study can be explained by the removal hypothesis, prioritization hypothesis, and protection-during-retrieval hypothesis. This work suggests that the mechanisms underlying the retro-cue effect are not mutually exclusive, but determined by the cue validity. Individuals can voluntarily choose different mechanisms based on the expected retro-cue validity.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9398
Author(s):  
Wanja A. Mössing ◽  
Niko A. Busch

The limited capacity of visual working memory (vWM) necessitates the efficient allocation of available resources by prioritizing relevant over irrelevant items. Retro-cues, which inform about the future relevance of items after encoding has already finished, can improve the quality of memory representations of the relevant items. A candidate mechanism of this retro-cueing benefit is lateralization of neural oscillations in the alpha-band, but its precise role is still debated. The relative decrease of alpha power contralateral to the relevant items has been interpreted as supporting inhibition of irrelevant distractors or as supporting maintenance of relevant items. Here, we aimed at resolving this debate by testing how the magnitude of alpha-band lateralization affects behavioral performance: does stronger lateralization improve the precision of the relevant memory or does it reduce the biasing influence of the irrelevant distractor? We found that it does neither: while the data showed a clear retro-cue benefit and a biasing influence of non-target items as well as clear cue-induced alpha-band lateralization, the magnitude of this lateralization was not correlated with any performance parameter. This finding may indicate that alpha-band lateralization, which is typically observed in response to mnemonic cues, indicates an automatic shift of attention that only coincides with, but is not directly involved in mnemonic prioritization.


2020 ◽  
Author(s):  
Sophia Becker ◽  
Andreas Nold ◽  
Tatjana Tchumatchenko

AbstractNeural representations of working memory maintain information temporarily and make it accessible for processing. This is most feasible in active, spiking representations. State-of-the-art modeling frameworks, however, reproduce working memory representations that are either transient but non-active or active but non-transient. Here, we analyze a biologically motivated working memory model which shows that synaptic short-term plasticity and noise emerging from spiking networks can jointly produce a working memory representation that is both active and transient. We investigate the effect of a synaptic signaling mechanism whose dysregulation is related to schizophrenia and show how it controls transient working memory duration through presynaptic, astrocytic and postsynaptic elements. Our findings shed light on the computational capabilities of healthy working memory function and offer a possible mechanistic explanation for how molecular alterations observed in psychiatric diseases such as schizophrenia can lead to working memory impairments.


2021 ◽  
Vol 11 (10) ◽  
pp. 1358
Author(s):  
Xue Guo ◽  
Ziyuan Li ◽  
Liangyou Zhang ◽  
Qiang Liu

Previous studies have found that transcranial alternating current stimulation (tACS) can significantly enhance individuals’ working memory performance. However, it is still unclear whether the memory performance enhancement was attributed to the quantity or the quality of working memory. The current study applies tACS over the right parietal cortex at slower (4 Hz) and faster (7 Hz) frequencies to participants with high and low working memory capacities in a color recall memory task. This enabled us to explore the tACS effects on the quantity and quality of the working memory for individuals with different memory capacities. The results revealed that slower frequency (4 Hz) tACS enhanced the quality of memory representations, and faster frequency (7 Hz) tACS principally impaired the quantity of working memory. The underlying mechanism of this effect might be that tACS at different frequencies modulate the memory resources, which then selectively affect the quantity and quality of memory representations. Importantly, individual traits, as well as memory strategies, may be crucial factors to consider when testing the effect of tACS on working memory performance.


2020 ◽  
Author(s):  
Gi-Yeul Bae

AbstractPrevious research demonstrated that visual working memory exhibits biases with respect to the categorical structure of the stimulus space. However, a majority of those studies used behavioral measures of working memory, and it is not clear whether the working memory representations per se are influenced by the categorical structure or whether the biases arise in decision or response processes during the report. Here, I applied a multivariate decoding technique to EEG data collected during working memory tasks to determine whether neural activity associated with the working memory representation is categorically biased prior to the report. I found that the decoding of spatial working memory was biased away from the nearest cardinal location, consistent with the biases observed in the behavioral responses. In a follow-up experiment which was designed to prevent the use of a response preparation strategy, I found that the decoding still exhibited categorical biases. Together, these results provide neural evidence that working memory representations themselves are categorically biased, imposing important constraints on the computational models of working memory representations.


2019 ◽  
Author(s):  
Danae Papadopetraki ◽  
Monja I. Froböse ◽  
Andrew Westbrook ◽  
Bram B. Zandbelt ◽  
Roshan Cools

AbstractExerting cognitive control is well known to be accompanied by a subjective effort cost and people are generally biased to avoid it. However, the nature of cognitive control costs is currently unclear. Recent theorizing suggests that the cost of cognitive effort serves as a motivational signal to bias the system away from excessive focusing (i.e. cognitive stability) and towards more cognitive flexibility. We asked whether the effort cost of cognitive stability is higher than that of cognitive flexibility. Specifically, we tested this prediction in the domain of working memory by using (i) a delayed response paradigm that allows us to manipulate demands for stability (distractor resistance) and flexibility (flexible updating) of working memory representations, as well as (ii) a subsequent cognitive effort discounting paradigm that allows us to quantify the subjective effort costs assigned to performing the delayed response paradigm. We show strong evidence, in two different samples (28 and 62 participants respectively) that subjective cost increases as a function of demand. Moreover, we demonstrate that the subjective cost of performing a task requiring cognitive stability (distractor resistance) is higher than that requiring flexible updating, supporting the hypothesis that the subjective effort cost of cognitive stability is higher than that of flexibility.


2021 ◽  
Vol 8 (7) ◽  
pp. 210254
Author(s):  
Naomi Langerock ◽  
Giuliana Sposito ◽  
Caro Hautekiet ◽  
Evie Vergauwe

The present study concerns a preregistered replication of the study conducted by Johnson et al . (Johnson et al. 2013 Psychol. Sci. 24 , 1104–1112 ( doi:10.1177/0956797612466414 )), in which they showed an inhibition-of-return-like effect in working memory. Inhibition of return is a well-known phenomenon observed in the field of perception and refers to the observation that it takes longer to look back at a location which has recently been explored than to look at an unexplored location. Working memory is a central concept in the field of cognitive psychology and refers to the capacity to process and maintain information simultaneously over short periods of time. Johnson's study applied the inhibition of return paradigm to the concept of working memory. Their results showed that it is harder to access a working memory representation that had just been thought of, i.e. refreshed, in comparison to an unrefreshed working memory representation. Contrary to this study of Johnson et al ., who observed refreshing to result in inhibitory processes, most studies on refreshing have described its effect as increasing/prolonging the level of activation of the memory representations. In an attempt to integrate these opposite patterns produced by ‘refreshing’, we started by replicating one of the studies on the inhibition of return in working memory reported by Johnson et al .


2017 ◽  
Vol 28 (12) ◽  
pp. 1773-1785 ◽  
Author(s):  
Young Eun Park ◽  
Jocelyn L. Sy ◽  
Sang Wook Hong ◽  
Frank Tong

A prevalent view of visual working memory (VWM) is that visual information is actively maintained in the form of perceptually integrated objects. Such reliance on object-based representations would predict that after an object is fully encoded into VWM, all features of that object would need to be maintained as a coherent unit. Here, we evaluated this idea by testing whether memory resources can be redeployed to a specific feature of an object already stored in VWM. We found that observers can utilize a retrospective cue presented during the maintenance period to attenuate both the gradual deterioration and complete loss of memory for a cued feature over time, but at the cost of accelerated loss of information regarding the uncued feature. Our findings demonstrate that object representations held within VWM can be decomposed into individual features and that having to retain additional features imposes greater demands on active maintenance processes.


2019 ◽  
Author(s):  
Laura-Isabelle Klatt ◽  
Stephan Getzmann ◽  
Alexandra Begau ◽  
Daniel Schneider

AbstractAttention can be allocated to mental representations to select information from working memory. To date, it remains ambiguous whether such retroactive shifts of attention involve the inhibition of irrelevant information or the prioritization of relevant information. Investigating asymmetries in posterior alpha-band oscillations during an auditory retroactive cueing task, we aimed at differentiating those mechanisms. Participants were cued to attend two out of three sounds in an upcoming sound array. Importantly, the resulting working memory representation contained one laterally and one centrally presented item. A centrally presented retro-cue then indicated the lateral, the central, or both items as further relevant for the task (comparing the cued item(s) to a memory probe). Time-frequency analysis revealed opposing patterns of alpha lateralization depending on target eccentricity: A contralateral decrease in alpha power in target lateral trials indicated the involvement of target prioritization. A contralateral increase in alpha power when the central item remained relevant (distractor lateral trials) suggested the de-prioritization of irrelevant information. No lateralization was observed when both items remained relevant, supporting the notion that auditory alpha lateralization is restricted to situations in which spatial information is task-relevant. Altogether, the data demonstrate that retroactive attentional deployment involves excitatory and inhibitory control mechanisms.


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