scholarly journals Functional connectivity within the neural system during maintenance period in visual working memory task

2010 ◽  
Vol 6 (6) ◽  
pp. 365-365
Author(s):  
S. Takahama ◽  
M. Misaki ◽  
S. Miyauchi ◽  
J. Saiki
Author(s):  
Selma Lugtmeijer ◽  
◽  
Linda Geerligs ◽  
Frank Erik de Leeuw ◽  
Edward H. F. de Haan ◽  
...  

AbstractWorking memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, 81 adults with sub-acute ischemic stroke and 29 elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.


2015 ◽  
Vol 27 (8) ◽  
pp. 1633-1647 ◽  
Author(s):  
Ben Deen ◽  
Rebecca Saxe ◽  
Marina Bedny

In congenital blindness, the occipital cortex responds to a range of nonvisual inputs, including tactile, auditory, and linguistic stimuli. Are these changes in functional responses to stimuli accompanied by altered interactions with nonvisual functional networks? To answer this question, we introduce a data-driven method that searches across cortex for functional connectivity differences across groups. Replicating prior work, we find increased fronto-occipital functional connectivity in congenitally blind relative to blindfolded sighted participants. We demonstrate that this heightened connectivity extends over most of occipital cortex but is specific to a subset of regions in the inferior, dorsal, and medial frontal lobe. To assess the functional profile of these frontal areas, we used an n-back working memory task and a sentence comprehension task. We find that, among prefrontal areas with overconnectivity to occipital cortex, one left inferior frontal region responds to language over music. By contrast, the majority of these regions responded to working memory load but not language. These results suggest that in blindness occipital cortex interacts more with working memory systems and raise new questions about the function and mechanism of occipital plasticity.


Author(s):  
Yurui Gao ◽  
Muwei Li ◽  
Anna S Huang ◽  
Adam W Anderson ◽  
Zhaohua Ding ◽  
...  

BACKGROUND: Schizophrenia, characterized by cognitive impairments, arises from a disturbance of brain network. Pathological changes in white matter (WM) have been indicated as playing a role in disturbing neural connectivity in schizophrenia. However, deficits of functional connectivity (FC) in individual WM bundles in schizophrenia have never been explored; neither have cognitive correlates with those deficits. METHODS: Resting-state and spatial working memory task fMRI images were acquired on 67 healthy subjects and 84 patients with schizophrenia. The correlations in blood-oxygenation-level-dependent (BOLD) signals between 46 WM and 82 gray matter regions were quantified, analyzed and compared between groups under three scenarios (i.e., resting state, retention period and entire time of a spatial working memory task). Associations of FC in WM with cognitive assessment scores were evaluated for three scenarios. RESULTS: FC deficits were significant (p<.05) in external capsule, cingulum, uncinate fasciculus, genu and body of corpus callosum under all three scenarios. Deficits were also present in the anterior limb of the internal capsule and cerebral peduncle in task scenario. Decreased FCs in specific WM bundles associated significantly (p<.05) with cognitive impairments in working memory, processing speed and/or cognitive control. CONCLUSIONS: Decreases in FC are evident in several WM bundles in patients with schizophrenia and are significantly associated with cognitive impairments during both rest and working memory tasks. Furthermore, working memory tasks expose FC deficits in more WM bundles and more cognitive associates in schizophrenia than resting state does.


2019 ◽  
Vol 10 (4) ◽  
pp. 204380871987614
Author(s):  
Nisha Yao ◽  
Marcus A. Rodriguez ◽  
Mengyao He ◽  
Mingyi Qian

Experimental studies have yielded discrepant results regarding the relationship between anxiety and attention bias to threat. Cognitive factors modulating the presence of threat-related attention bias in anxiety have drawn growing attention. Previous research demonstrated that visual working memory (WM) representations can guide attention allocation in a top-down manner. Whether threat-related WM representations affected the presence of attention bias in anxiety awaits examination. Combining a memory task and a dot-probe task, this study investigated how WM representations of faces with neutral or negative expressions modulated the attention bias to threat among highly anxious individuals versus controls. Results showed that highly anxious individuals developed more pronounced attention bias to threat when maintaining WM representations of negative faces as compared to the control group. There were no significant between-group effects when the WM representations were neutral. These results suggested that highly anxious individuals were more susceptible to the influence of mental representations with negative valence on attention deployment.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 98-98
Author(s):  
Corinne Cannavale ◽  
Caitlyn Edwards ◽  
Ruyu Liu ◽  
Samantha Iwinski ◽  
Anne Walk ◽  
...  

Abstract Objectives Carotenoids are plant pigments known to deposit in neural tissues including the hippocampus, a brain substrate that supports several memory forms. However, there is a dearth of knowledge regarding carotenoid status and working memory function in children. Accordingly, this study aimed to understand the relationship between macular and skin carotenoids to visual and auditory working memory (WM) function. Methods Seventy preadolescent children (7–12 years, 32 males) were recruited from the East-Central Illinois area. Auditory working memory was assessed using the story recall subtest of the Woodcock-Johnson IV Test of Cognitive Abilities. A subsample (N = 61, 27 males) completed a visual working memory task and reaction time was quantified to determine speed of memory processing at set sizes of 1 to 4 items. Macular pigment optical density (MPOD) was assessed using customized heterochromatic flicker photometry. Skin carotenoids were assessed using reflection spectroscopy (Veggie Meter). Hierarchical linear regressions were conducted to assess the relationship between carotenoid status and WM function, while controlling for age, sex, income, and whole-body % fat (DXA). Results Auditory WM was positively associated with skin carotenoids (b = 0.263, P = 0.039) but not MPOD (b = −0.044, P = 0.380). In contrast, MPOD was significantly associated with faster visual WM speed at set size 3 (b = −0.253, P = 0.039) and trending at set sizes of 1 (b = −0.225, P = 0.051), 2 (b = −0.171, P = 0.121), and 4 (b = −0.230, P = 0.055). Interestingly, skin carotenoids were not related to visual WM performance at either set size (all P’s &gt; 0.300). Conclusions These results indicate that auditory and visual WM may be differentially related to carotenoids. While skin carotenoids encompass all carotenoids consumed in diet, lutein and zeaxanthin are the only carotenoids which deposit in the macula. Given that MPOD was only related to visual WM, this suggests lutein plays a larger role in these neural functions relative to auditory WM. Interestingly, MPOD's relationship with visual WM increased in strength with the more difficult trial type (i.e., increasing set size), indicating MPOD is related at higher levels of WM capacity. Funding Sources This study was funded by the Egg Nutrition Center.


2020 ◽  
Vol 7 (8) ◽  
pp. 190228 ◽  
Author(s):  
Quan Wan ◽  
Ying Cai ◽  
Jason Samaha ◽  
Bradley R. Postle

How does the neural representation of visual working memory content vary with behavioural priority? To address this, we recorded electroencephalography (EEG) while subjects performed a continuous-performance 2-back working memory task with oriented-grating stimuli. We tracked the transition of the neural representation of an item ( n ) from its initial encoding, to the status of ‘unprioritized memory item' (UMI), and back to ‘prioritized memory item', with multivariate inverted encoding modelling. Results showed that the representational format was remapped from its initially encoded format into a distinctive ‘opposite' representational format when it became a UMI and then mapped back into its initial format when subsequently prioritized in anticipation of its comparison with item n + 2. Thus, contrary to the default assumption that the activity representing an item in working memory might simply get weaker when it is deprioritized, it may be that a process of priority-based remapping helps to protect remembered information when it is not in the focus of attention.


NeuroImage ◽  
2009 ◽  
Vol 47 ◽  
pp. S166
Author(s):  
DD Jolles ◽  
MJ Grol ◽  
MA Van Buchem ◽  
EA Crone ◽  
SARB Rombouts

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