scholarly journals Working memory content is distorted by its use in perceptual comparisons

2020 ◽  
Author(s):  
Keisuke Fukuda ◽  
April Emily Pereira ◽  
Joseph M. Saito ◽  
Ty Yi Tang ◽  
Hiroyuki Tsubomi ◽  
...  
Keyword(s):  
Working Memory ◽  
Individual Differences ◽  
Computational Modeling ◽  
Visual Information ◽  
Dynamic Environment ◽  
Memory Bias ◽  
General Mechanism ◽  
Memory Representation ◽  
Memory Representations ◽  
Memory Content

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.

scholarly journals Gray Matter Volume in Different Cortical Structures Dissociably Relates to Individual Differences in Capacity and Precision of Visual Working Memory

2020 ◽  
Vol 30 (9) ◽  
pp. 4759-4770
Author(s):  
Maro G Machizawa ◽  
Jon Driver ◽  
Takeo Watanabe
Keyword(s):  
Working Memory ◽  
Individual Differences ◽  
Visual Working Memory ◽  
Gray Matter ◽  
Visual Information ◽  
Parietal Lobe ◽  
Brain Activity ◽  
Gray Matter Volume ◽  
Brain Anatomy

Abstract Visual working memory (VWM) refers to our ability to selectively maintain visual information in a mental representation. While cognitive limits of VWM greatly influence a variety of mental operations, it remains controversial whether the quantity or quality of representations in mind constrains VWM. Here, we examined behavior-to-brain anatomical relations as well as brain activity to brain anatomy associations with a “neural” marker specific to the retention interval of VWM. Our results consistently indicated that individuals who maintained a larger number of items in VWM tended to have a larger gray matter (GM) volume in their left lateral occipital region. In contrast, individuals with a superior ability to retain with high precision tended to have a larger GM volume in their right parietal lobe. These results indicate that individual differences in quantity and quality of VWM may be associated with regional GM volumes in a dissociable manner, indicating willful integration of information in VWM may recruit separable cortical subsystems.

scholarly journals Shielding working-memory representations from temporally predictable external interference

2021 ◽  
Author(s):  
Daniela Gresch ◽  
Sage Boettcher ◽  
Freek van Ede ◽  
Anna C. Nobre
Keyword(s):  
Working Memory ◽  
Memory Performance ◽  
Memory Task ◽  
Memory Retention ◽  
Protective Effects ◽  
External Interference ◽  
Irrelevant Distractors ◽  
Temporal Predictability ◽  
Memory Representations ◽  
Memory Content

Protecting working-memory content from distracting external sensory inputs and intervening tasks is a ubiquitous demand in daily life. Here, we ask whether and how temporal expectations about external events can help mitigate effects of such interference during working-memory retention. We manipulated the temporal predictability of interfering items that occurred during the retention period of a visual working-memory task and report that temporal expectations reduce the detrimental influence of external interference on subsequent memory performance. Moreover, to determine if the protective effects of temporal expectations rely mainly on distractor suppression or also involve shielding of internal representations, we compared effects after irrelevant distractors that could be ignored vs. interrupters that required a response. Whereas distractor suppression may be sufficient to confer protection from predictable distractors, any benefits after interruption are likely to involve memory shielding. We found similar benefits of temporal expectations after both types of interference. We conclude that temporal expectations may play an important role in safeguarding behaviour based on working memory – acting, at least partly, through mechanisms that include the shielding of internal content from external interference.

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
Keyword(s):  
Working Memory ◽  
Memory Representation ◽  
Alpha Power ◽  
Attentional Orienting ◽  
Cognitive Mechanisms ◽  
Storage And Retrieval ◽  
Irrelevant Item ◽  
Memory Representations ◽  
The Cost ◽  
Memory Resources

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.

scholarly journals Formation and synaptic control of active transient working memory representations

2020 ◽  
Author(s):  
Sophia Becker ◽  
Andreas Nold ◽  
Tatjana Tchumatchenko
Keyword(s):  
Working Memory ◽  
Memory Function ◽  
Mechanistic Explanation ◽  
Memory Representation ◽  
Signaling Mechanism ◽  
Memory Impairments ◽  
Molecular Alterations ◽  
Healthy Working ◽  
Memory Representations ◽  
Synaptic Control

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.

scholarly journals Neural evidence for categorical biases in working memory for location and orientation

2020 ◽  
Author(s):  
Gi-Yeul Bae
Keyword(s):  
Working Memory ◽  
Computational Models ◽  
Spatial Working Memory ◽  
Memory Representation ◽  
Response Preparation ◽  
Behavioral Measures ◽  
Eeg Data ◽  
Categorical Structure ◽  
Memory Representations ◽  
Preparation Strategy

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.

scholarly journals Interval between two sequential arrays determines their storage state in visual working memory

2020 ◽  
Author(s):  
Ziyuan Li ◽  
Jiafeng Zhang ◽  
Tengfei Liang ◽  
Chaoxiong Ye ◽  
Qiang Liu
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Information ◽  
Active State ◽  
Passive State ◽  
Dynamic Nature ◽  
Retention Period ◽  
Memory Representations ◽  
Interval Condition ◽  
First Time

AbstractThe visual information can be stored as either “active” representations in the active state or “activity-silent” representations in the passive state during the retention period in visual working memory (VWM). Catering to the dynamic nature of visual world, we explored how the temporally dynamic visual input was stored in VWM. In the current study, the memory arrays were presented sequentially, and the contralateral delay activity (CDA), an electrophysiological measure, was used to identify whether the memory representations were transferred into the passive state. Participants were instructed to encode two sequential arrays and retrieve them respectively, with two conditions of interval across the two arrays: 400ms and 800ms. These results provided strong evidence for the state-separated storage of two sequential arrays in different neural states if the interval between them was long enough, and the concurrent storage of them in the active state if the interval was relatively short. This conclusion was valid only when the participants encountered the task for the first time. Once participants have formed their mindset, they would apply the same storage mode to the subsequently extended or shortened interval condition.

scholarly journals Inhibition-of-return-like effects in working memory? A preregistered replication study of Johnson et al . (2013)

2021 ◽  
Vol 8 (7) ◽  
pp. 210254
Author(s):  
Naomi Langerock ◽  
Giuliana Sposito ◽  
Caro Hautekiet ◽  
Evie Vergauwe
Keyword(s):  
Working Memory ◽  
Cognitive Psychology ◽  
Inhibition Of Return ◽  
Replication Study ◽  
Memory Representation ◽  
Central Concept ◽  
Inhibitory Processes ◽  
Look Back ◽  
Memory Inhibition ◽  
Memory Representations

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 .

scholarly journals Working memory performance is tied to stimulus complexity

2021 ◽  
Author(s):  
Roland Pusch ◽  
Julian Packheiser ◽  
Amir Hossein Azizi ◽  
Celil Semih Sevincik ◽  
Jonas Rose ◽  
...  
Keyword(s):  
Working Memory ◽  
Visual Information ◽  
Neural Coding ◽  
Single Unit ◽  
Memory Performance ◽  
Delay Period ◽  
Memory Representation ◽  
Stimulus Complexity ◽  
Behavioral Experiments ◽  
Complex Stimuli

1.SummaryWorking memory is the cognitive capability to maintain and process information over short periods. Recent behavioral and computational studies have shown that increased visual information of the presented stimulus material is associated with enhanced working memory performance. However, the underlying neural correlates of this association are unknown. To identify how stimuli of different visual information levels affect working memory performance, we conducted behavioral experiments and single unit recordings in the avian analog of the prefrontal cortex, the nidopallium caudolaterale (NCL). On the behavioral level, we confirmed that feature-rich complex stimuli demonstrated higher working memory performance compared to feature-poor simple stimuli. This difference was reflected by distinct neural coding patterns at the single unit level. For complex stimuli, we found a highly multiplexed neuronal code. During the sample presentation, NCL neurons initially reflected both visual and value-related features of the presented stimuli that switched to a representation of the upcoming choice during a delay period. When processing simple stimuli, NCL neurons did not multiplex and represented the upcoming choice already during stimulus presentation and throughout the delay period. It is conceivable that the maintenance of the upcoming choice in working memory was prolonged for simple stimuli due to the early choice representation. This possibly resulted in increased decay of the working memory trace ultimately leading to a decrease in performance. In conclusion, we found that increases in stimulus complexity are associated with increased neuronal multiplexing of the working memory representation. This could possibly allow for a facilitated read-out of the neural code resulting in further enhancements of working memory performance.

scholarly journals Independent Attention Mechanisms Control the Activation of Tactile and Visual Working Memory Representations

2018 ◽  
Vol 30 (5) ◽  
pp. 644-655 ◽  
Author(s):  
Tobias Katus ◽  
Martin Eimer
Keyword(s):  
Working Memory ◽  
Color Change ◽  
Memory Systems ◽  
Behavioral Experiment ◽  
General Mechanism ◽  
Visual Modality ◽  
Control Mechanisms ◽  
Specific Memory ◽  
Tactile Stimuli ◽  
Memory Representations

Working memory (WM) is limited in capacity, but it is controversial whether these capacity limitations are domain-general or are generated independently within separate modality-specific memory systems. These alternative accounts were tested in bimodal visual/tactile WM tasks. In Experiment 1, participants memorized the locations of simultaneously presented task-relevant visual and tactile stimuli. Visual and tactile WM load was manipulated independently (one, two, or three items per modality), and one modality was unpredictably tested after each trial. To track the activation of visual and tactile WM representations during the retention interval, the visual contralateral delay activity (CDA) and tactile CDA (tCDA) were measured over visual and somatosensory cortex, respectively. CDA and tCDA amplitudes were selectively affected by WM load in the corresponding (tactile or visual) modality. The CDA parametrically increased when visual load increased from one to two and to three items. The tCDA was enhanced when tactile load increased from one to two items and showed no further enhancement for three tactile items. Critically, these load effects were strictly modality-specific, as substantiated by Bayesian statistics. Increasing tactile load did not affect the visual CDA, and increasing visual load did not modulate the tCDA. Task performance at memory test was also unaffected by WM load in the other (untested) modality. This was confirmed in a second behavioral experiment where tactile and visual loads were either two or four items, unimodal baseline conditions were included, and participants performed a color change detection task in the visual modality. These results show that WM capacity is not limited by a domain-general mechanism that operates across sensory modalities. They suggest instead that WM storage is mediated by distributed modality-specific control mechanisms that are activated independently and in parallel during multisensory WM.

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