scholarly journals Neural Correlates of Visual Working Memory Capacity in the Posterior Parietal Cortex

2013 ◽  
Vol 13 (9) ◽  
pp. 8-8
Author(s):  
M. Riley ◽  
B. Lambert ◽  
X.-L. Qi ◽  
C. Constantinidis
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Working Memory Capacity ◽  
Memory Capacity ◽  
Neural Correlates ◽  
Posterior Parietal

scholarly journals On the Role of the Inferior Intraparietal Sulcus in Visual Working Memory for Lateralized Single-feature Objects

2017 ◽  
Vol 29 (2) ◽  
pp. 337-351 ◽  
Author(s):  
Sabrina Brigadoi ◽  
Simone Cutini ◽  
Federica Meconi ◽  
Marco Castellaro ◽  
Paola Sessa ◽  
...  
Keyword(s):  
Working Memory ◽  
Change Detection ◽  
Functional Response ◽  
Visual Working Memory ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Memory Load ◽  
Intraparietal Sulcus ◽  
Posterior Parietal ◽  
Electromagnetic Signals

A consolidated practice in cognitive neuroscience is to explore the properties of human visual working memory through the analysis of electromagnetic signals using cued change detection tasks. Under these conditions, EEG/MEG activity increments in the posterior parietal cortex scaling with the number of memoranda are often reported in the hemisphere contralateral to the objects' position in the memory array. This highly replicable finding clashes with several reported failures to observe compatible hemodynamic activity modulations using fMRI or fNIRS in comparable tasks. Here, we reconcile this apparent discrepancy by acquiring fMRI data on healthy participants and employing a cluster analysis to group voxels in the posterior parietal cortex based on their functional response. The analysis identified two distinct subpopulations of voxels in the intraparietal sulcus (IPS) showing a consistent functional response among participants. One subpopulation, located in the superior IPS, showed a bilateral response to the number of objects coded in visual working memory. A different subpopulation, located in the inferior IPS, showed an increased unilateral response when the objects were displayed contralaterally. The results suggest that a cluster of neurons in the inferior IPS is a candidate source of electromagnetic contralateral responses to working memory load in cued change detection tasks.

scholarly journals Transdiagnostic comparison of visual working memory capacity in bipolar disorder and schizophrenia

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Catherine V. Barnes-Scheufler ◽  
Caroline Passow ◽  
Lara Rösler ◽  
Jutta S. Mayer ◽  
Viola Oertel ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Working Memory ◽  
Visual Working Memory ◽  
Effect Size ◽  
Working Memory Capacity ◽  
Memory Capacity ◽  
Medium Effect ◽  
Full Spectrum ◽  
Small Effect Size ◽  
The Difference

Abstract Background Impaired working memory is a core cognitive deficit in both bipolar disorder and schizophrenia. Its study might yield crucial insights into the underpinnings of both disorders on the cognitive and neurophysiological level. Visual working memory capacity is a particularly promising construct for such translational studies. However, it has not yet been investigated across the full spectrum of both disorders. The aim of our study was to compare the degree of reductions of visual working memory capacity in patients with bipolar disorder (PBD) and patients with schizophrenia (PSZ) using a paradigm well established in cognitive neuroscience. Methods 62 PBD, 64 PSZ, and 70 healthy controls (HC) completed a canonical visual change detection task. Participants had to encode the color of four circles and indicate after a short delay whether the color of one of the circles had changed or not. We estimated working memory capacity using Pashler’s K. Results Working memory capacity was significantly reduced in both PBD and PSZ compared to HC. We observed a small effect size (r = .202) for the difference between HC and PBD and a medium effect size (r = .370) for the difference between HC and PSZ. Working memory capacity in PSZ was also significantly reduced compared to PBD with a small effect size (r = .201). Thus, PBD showed an intermediate level of impairment. Conclusions These findings provide evidence for a gradient of reduced working memory capacity in bipolar disorder and schizophrenia, with PSZ showing the strongest degree of impairment. This underscores the importance of disturbed information processing for both bipolar disorder and schizophrenia. Our results are compatible with the cognitive manifestation of a neurodevelopmental gradient affecting bipolar disorder to a lesser degree than schizophrenia. They also highlight the relevance of visual working memory capacity for the development of both behavior- and brain-based transdiagnostic biomarkers.

Greater Visual Working Memory Capacity for Visually Matched Stimuli When They Are Perceived as Meaningful

2021 ◽  
Vol 33 (5) ◽  
pp. 902-918 ◽  
Author(s):  
Isabel E. Asp ◽  
Viola S. Störmer ◽  
Timothy F. Brady
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Information ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Visual Complexity ◽  
Memory Capacity ◽  
Subjective Perception ◽  
Neural Delay ◽  
Meaningful Stimuli

Abstract Almost all models of visual working memory—the cognitive system that holds visual information in an active state—assume it has a fixed capacity: Some models propose a limit of three to four objects, where others propose there is a fixed pool of resources for each basic visual feature. Recent findings, however, suggest that memory performance is improved for real-world objects. What supports these increases in capacity? Here, we test whether the meaningfulness of a stimulus alone influences working memory capacity while controlling for visual complexity and directly assessing the active component of working memory using EEG. Participants remembered ambiguous stimuli that could either be perceived as a face or as meaningless shapes. Participants had higher performance and increased neural delay activity when the memory display consisted of more meaningful stimuli. Critically, by asking participants whether they perceived the stimuli as a face or not, we also show that these increases in visual working memory capacity and recruitment of additional neural resources are because of the subjective perception of the stimulus and thus cannot be driven by physical properties of the stimulus. Broadly, this suggests that the capacity for active storage in visual working memory is not fixed but that more meaningful stimuli recruit additional working memory resources, allowing them to be better remembered.

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