scholarly journals Remembering stimuli in different depth planes increases visual working memory precision and reduces swap errors.

2017 ◽  
Vol 17 (10) ◽  
pp. 848
Author(s):  
Chaipat Chunharas ◽  
Rademaker Rosanne ◽  
Thomas Sprague ◽  
Timothy Brady ◽  
John Serences
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Memory Precision

scholarly journals Atypically larger variability of resource allocation accounts for visual working memory deficits in schizophrenia

2018 ◽  
Author(s):  
Yi-Jie Zhao ◽  
Tianye Ma ◽  
Xuemei Ran ◽  
Li Zhang ◽  
Ru-Yuan Zhang ◽  
...  
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Computational Models ◽  
Variable Precision ◽  
Capacity Theory ◽  
Healthy Control ◽  
New Perspective ◽  
Almost All ◽  
Memory Precision ◽  
Memory Resources

AbstractSchizophrenia patients are known to have profound deficits in visual working memory (VWM), and almost all previous studies attribute the deficits to decreased memory capacity. This account, however, ignores the potential contributions of other VWM components (e.g., memory precision). Here, we measure the VWM performance of schizophrenia patients and healthy control subjects on two classical delay-estimation tasks. Moreover, we thoroughly evaluate several established computational models of VWM to compare the performance of the two groups. We find that the model assuming variable precision across items and trials is the best model to explain the performance of both groups. According to the variable-precision model, schizophrenia subjects exhibit abnormally larger variability of allocating memory resources rather than resources per se. These results invite a rethink of the widely accepted decreased-capacity theory and propose a new perspective on the diagnosis and rehabilitation of schizophrenia.

scholarly journals Perceptual Precision Predicts Visual Working Memory Precision

2013 ◽  
Vol 13 (9) ◽  
pp. 1360-1360
Author(s):  
D. W. Sutterer ◽  
D. E. Anderson ◽  
E. Awh
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Memory Precision

scholarly journals Dopamine modulates visual working memory precision

2012 ◽  
Vol 12 (9) ◽  
pp. 350-350 ◽  
Author(s):  
N. Zokaei ◽  
N. Gorgoraptis ◽  
M. Husain
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Memory Precision

Insights into visual working memory precision at the feature- and object-level from a hemispheric encoding manipulation

2020 ◽  
Vol 73 (11) ◽  
pp. 1949-1968
Author(s):  
Elena M Galeano Weber ◽  
Haley Keglovits ◽  
Arin Fisher ◽  
Silvia A Bunge
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Right Hemisphere ◽  
Single Object ◽  
Mnemonic Precision ◽  
Parallel Feature ◽  
Spatial Size ◽  
Memory Precision ◽  
Distinct Features ◽  
Object Level

Mnemonic precision is an important aspect of visual working memory (WM). Here, we probed mechanisms that affect precision for spatial (size) and non-spatial (colour) features of an object, and whether these features are encoded and/or stored separately in WM. We probed precision at the feature-level—that is, whether different features of a single object are represented separately or together in WM—and the object-level—that is, whether different features across a set of sequentially presented objects are represented in the same or different WM stores. By manipulating whether stimuli were encoded by the left and/or right hemisphere, we gained further insights into how objects are represented in WM. At the feature-level, we tested whether recall fidelity for the two features of an object fluctuated in tandem from trial to trial. We observed no significant coupling under either central or lateralized encoding, supporting the claim of parallel feature channels at encoding. At the level of WM storage of a set of objects, we found asymmetric feature interference under central encoding, whereby an increase in colour load led to a decrease in size precision. When objects were encoded by a single hemisphere, however, we found largely independent feature stores. Precision for size was more resistant to interference from the size of another object under right-hemisphere encoding; by contrast, precision for colour did not differ across hemispheres, suggesting a more distributed WM store. These findings suggest that distinct features of a single object are represented separately but are then partially integrated during maintenance of a set of sequentially presented objects.

scholarly journals Neural mechanisms underlying the precision of visual working memory

2018 ◽  
Author(s):  
Yijie Zhao ◽  
Shuguang Kuai ◽  
Theodore P. Zanto ◽  
Yixuan Ku
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Memory Load ◽  
Neural Mechanisms ◽  
Behavioral Experiment ◽  
Working Memory Load ◽  
Lateral Occipital Complex ◽  
The Individual ◽  
Memory Precision ◽  
The Brain

AbstractThe neural mechanisms associated with the limited capacity of working memory has long been studied, but it is still unclear how the brain maintains the fidelity of representations in working memory. Here, an orientation recall task for estimating the precision of visual working memory was performed both inside and outside an fMRI scanner. Results showed that the trial-by-trial recall error (in radians) was correlated with delay period activity in the lateral occipital complex (LOC) during working memory maintenance, regardless of the memory load. Moreover, delay activity in LOC also correlated with the individual participant’s precision of working memory from a separate behavioral experiment held two weeks prior. Furthermore, a region within the prefrontal cortex, the inferior frontal junction (IFJ), exhibited greater functional connectivity with LOC when the working memory load increased. Together, our findings provide unique evidence that the LOC supports visual working memory precision, while communication between the IFJ and LOC varys with visual working memory load.

scholarly journals Is categorization in visual working memory a way to reduce mental effort? A pupillometry study

2021 ◽  
Author(s):  
Cherie Zhou ◽  
Monicque M. Lorist ◽  
Sebastiaan Mathot
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Information ◽  
Pupil Size ◽  
Mental Effort ◽  
Pupil Dilation ◽  
General Category ◽  
Set Size ◽  
Memory Precision ◽  
Continuous Representations

Recent studies on visual working memory (VWM) have shown that visual information can be stored in VWM as continuous (e.g., a specific shade of red) as well as categorical representations (e.g., the general category red). It has been widely assumed, yet never directly tested, that continuous representations require more VWM mental effort than categorical representations; given limited VWM capacity, this would mean that fewer continuous, as compared to categorical, representations can be maintained simultaneously. We tested this assumption by measuring pupil size, as a proxy for mental effort, in a delayed estimation task. Participants memorized one to four ambiguous (boundaries between adjacent color categories) or prototypical colors to encourage continuous or categorical representations, respectively; after a delay, a probe indicated the location of the to-be-reported color. We found that, for set size 1, pupil size was larger while maintaining ambiguous as compared to prototypical colors, but without any difference in memory precision; this suggests that participants relied on an effortful continuous representation to maintain a single ambiguous color, thus resulting in pupil dilation while preserving precision. In contrast, for set size 2 and higher, pupil size was equally large while maintaining ambiguous and prototypical colors, but memory precision was now substantially reduced for ambiguous colors; this suggests that participants now also relied on categorical representations for ambiguous colors (which are by definition a poor fit to any category), thus reducing memory precision but not resulting in pupil dilation. Taken together, our results suggest that continuous representations are more effortful than categorical representations, and that very few continuous representations (perhaps only one) can be maintained simultaneously.

scholarly journals Superior Intraparietal Sulcus Controls the Variability of Visual Working Memory Precision

2016 ◽  
Vol 36 (20) ◽  
pp. 5623-5635 ◽  
Author(s):  
E. M. Galeano Weber ◽  
B. Peters ◽  
T. Hahn ◽  
C. Bledowski ◽  
C. J. Fiebach
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Intraparietal Sulcus ◽  
Memory Precision
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