scholarly journals Dissociable Mechanisms of Verbal Working Memory Revealed through Multivariate Lesion Mapping

2019 ◽  
Vol 30 (4) ◽  
pp. 2542-2554 ◽  
Author(s):  
Maryam Ghaleh ◽  
Elizabeth H Lacey ◽  
Mackenzie E Fama ◽  
Zainab Anbari ◽  
Andrew T DeMarco ◽  
...  
Keyword(s):  
Working Memory ◽  
Spatial Working Memory ◽  
Superior Temporal Gyrus ◽  
Verbal Working Memory ◽  
Brain Structures ◽  
Brain Regions ◽  
Task Demands ◽  
Auditory Information ◽  
Verbal Information ◽  
Task Conditions

Abstract Two maintenance mechanisms with separate neural systems have been suggested for verbal working memory: articulatory-rehearsal and non-articulatory maintenance. Although lesion data would be key to understanding the essential neural substrates of these systems, there is little evidence from lesion studies that the two proposed mechanisms crucially rely on different neuroanatomical substrates. We examined 39 healthy adults and 71 individuals with chronic left-hemisphere stroke to determine if verbal working memory tasks with varying demands would rely on dissociable brain structures. Multivariate lesion–symptom mapping was used to identify the brain regions involved in each task, controlling for spatial working memory scores. Maintenance of verbal information relied on distinct brain regions depending on task demands: sensorimotor cortex under higher demands and superior temporal gyrus (STG) under lower demands. Inferior parietal cortex and posterior STG were involved under both low and high demands. These results suggest that maintenance of auditory information preferentially relies on auditory-phonological storage in the STG via a nonarticulatory maintenance when demands are low. Under higher demands, sensorimotor regions are crucial for the articulatory rehearsal process, which reduces the reliance on STG for maintenance. Lesions to either of these regions impair maintenance of verbal information preferentially under the appropriate task conditions.

scholarly journals Lower Working Memory Performance in Overweight and Obese Adolescents Is Mediated by White Matter Microstructure

2015 ◽  
Vol 22 (3) ◽  
pp. 281-292 ◽  
Author(s):  
Gabriela Alarcón ◽  
Siddharth Ray ◽  
Bonnie J. Nagel
Keyword(s):  
Working Memory ◽  
White Matter ◽  
Spatial Working Memory ◽  
Memory Performance ◽  
Gray Matter Volume ◽  
Verbal Working Memory ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Bold Signal ◽  
The Relationship

AbstractObjectives: Elevated body mass index (BMI) is associated with deficits in working memory, reduced gray matter volume in frontal and parietal lobes, as well as changes in white matter (WM) microstructure. The current study examined whether BMI was related to working memory performance and blood oxygen level dependent (BOLD) activity, as well as WM microstructure during adolescence. Methods: Linear regressions with BMI and (1) verbal working memory BOLD signal, (2) spatial working memory BOLD signal, and (3) fractional anisotropy (FA), a measure of WM microstructure, were conducted in a sample of 152 healthy adolescents ranging in BMI. Results: BMI was inversely related to IQ and verbal and spatial working memory accuracy; however, there was no significant relationship between BMI and BOLD response for either verbal or spatial working memory. Furthermore, BMI was negatively correlated with FA in the left superior longitudinal fasciculus (SLF) and left inferior longitudinal fasciculus (ILF). ILF FA and IQ significantly mediated the relationship between BMI and verbal working memory performance, whereas SLF FA, but not IQ, significantly mediated the relationship between BMI and accuracy of both verbal and spatial working memory. Conclusions: These findings indicate that higher BMI is associated with decreased FA in WM fibers connecting brain regions that support working memory, and that WM microstructural deficits may underlie inferior working memory performance in youth with higher BMI. Of interest, BMI did not show the same relationship with working memory BOLD activity, which may indicate that changes in brain structure precede changes in function. (JINS, 2015, 21, 281–292)

scholarly journals Individual-subject functional localization increases univariate activation but not multivariate pattern discriminability in the ‘multiple-demand’ frontoparietal network

2019 ◽  
Author(s):  
Sneha Shashidhara ◽  
Floortje S. Spronkers ◽  
Yaara Erez
Keyword(s):  
Working Memory ◽  
Spatial Organization ◽  
Spatial Working Memory ◽  
Verbal Working Memory ◽  
Brain Regions ◽  
Fmri Data ◽  
Criterion Task ◽  
Frontoparietal Network ◽  
Subject Specific ◽  
The Subject

AbstractThe frontoparietal ‘multiple-demand’ (MD) control network plays a key role in goal-directed behavior. Recent developments of multivoxel pattern analysis (MVPA) for fMRI data allow for more fine-grained investigations into the functionality and properties of brain systems. In particular, MVPA in the MD network was used to gain better understanding of control processes such as attentional effects, adaptive coding, and representation of multiple task-relevant features, but overall low decoding levels have limited its use for this network. A common practice of applying MVPA is by investigating pattern discriminability within a region-of-interest (ROI) using a template mask, thus ensuring that the same brain areas are studied in all participants. This approach offers high sensitivity, but does not take into account differences between individuals in the spatial organization of brain regions. An alternative approach uses independent localizer data for each subject to select the most responsive voxels and define individual ROIs within the boundaries of a group template. Such an approach allows for a refined and targeted localization based on the unique pattern of activity of individual subjects while ensuring that functionally similar brain regions are studied for all subjects. In the current study we tested whether using individual ROIs leads to changes in decodability of task-related neural representations as well as univariate activity across the MD network compared to when using a group template. We used three localizer tasks to separately define subject-specific ROIs: spatial working memory, verbal working memory, and a Stroop task. We then systematically assessed univariate and multivariate results in a separate rule-based criterion task. All the localizer tasks robustly recruited the MD network and evoked highly reliable activity patterns in individual subjects. Consistent with previous studies, we found a clear benefit of the subject-specific ROIs for univariate results from the criterion task, with increased activity in the individual ROIs based on the localizers’ data, compared to the activity observed when using the group template. In contrast, there was no benefit of the subject-specific ROIs for the multivariate results in the form of increased discriminability, as well as no cost of reduced discriminability. Both univariate and multivariate results were similar in the subject-specific ROIs defined by each of the three localizers. Our results provide important empirical evidence for researchers in the field of cognitive control for the use of individual ROIs in the frontoparietal network for both univariate and multivariate analysis of fMRI data, and serve as another step towards standardization and increased comparability across studies.

scholarly journals Individual-subject Functional Localization Increases Univariate Activation but Not Multivariate Pattern Discriminability in the “Multiple-demand” Frontoparietal Network

2020 ◽  
Vol 32 (7) ◽  
pp. 1348-1368 ◽  
Author(s):  
Sneha Shashidhara ◽  
Floortje S. Spronkers ◽  
Yaara Erez
Keyword(s):  
Working Memory ◽  
Spatial Organization ◽  
Spatial Working Memory ◽  
Verbal Working Memory ◽  
Brain Regions ◽  
Fmri Data ◽  
Criterion Task ◽  
Frontoparietal Network ◽  
Subject Specific ◽  
The Subject

The frontoparietal “multiple-demand” (MD) control network plays a key role in goal-directed behavior. Recent developments of multivoxel pattern analysis (MVPA) for fMRI data allow for more fine-grained investigations into the functionality and properties of brain systems. In particular, MVPA in the MD network was used to gain better understanding of control processes such as attentional effects, adaptive coding, and representation of multiple task-relevant features, but overall low decoding levels have limited its use for this network. A common practice of applying MVPA is by investigating pattern discriminability within a ROI using a template mask, thus ensuring that the same brain areas are studied in all participants. This approach offers high sensitivity but does not take into account differences between individuals in the spatial organization of brain regions. An alternative approach uses independent localizer data for each subject to select the most responsive voxels and define individual ROIs within the boundaries of a group template. Such an approach allows for a refined and targeted localization based on the unique pattern of activity of individual subjects while ensuring that functionally similar brain regions are studied for all subjects. In the current study, we tested whether using individual ROIs leads to changes in decodability of task-related neural representations as well as univariate activity across the MD network compared with when using a group template. We used three localizer tasks to separately define subject-specific ROIs: spatial working memory, verbal working memory, and a Stroop task. We then systematically assessed univariate and multivariate results in a separate rule-based criterion task. All the localizer tasks robustly recruited the MD network and evoked highly reliable activity patterns in individual subjects. Consistent with previous studies, we found a clear benefit of the subject-specific ROIs for univariate results from the criterion task, with increased activity in the individual ROIs based on the localizers' data, compared with the activity observed when using the group template. In contrast, there was no benefit of the subject-specific ROIs for the multivariate results in the form of increased discriminability, as well as no cost of reduced discriminability. Both univariate and multivariate results were similar in the subject-specific ROIs defined by each of the three localizers. Our results provide important empirical evidence for researchers in the field of cognitive control for the use of individual ROIs in the frontoparietal network for both univariate and multivariate analysis of fMRI data and serve as another step toward standardization and increased comparability across studies.

Shared Predictors of Academic Achievement in Children with ADHD: A Multi-Sample Study

2021 ◽  
pp. 108705472110120
Author(s):  
Kelly D. Carrasco ◽  
Chi-Ching Chuang ◽  
Gail Tripp
Keyword(s):  
Academic Achievement ◽  
Working Memory ◽  
Word Reading ◽  
Spatial Working Memory ◽  
Verbal Working Memory ◽  
The United States ◽  
Children With Adhd ◽  
Visual Spatial ◽  
Visual Spatial Working Memory ◽  
Predictors Of Academic Achievement

Objective: To identify common and shared predictors of academic achievement across samples of children with ADHD. Method: Two clinically referred samples from New Zealand (1 n = 88, 82% boys; 2 n = 121, 79% boys) and two community samples from the United States (3 n = 111, 65% boys; 4 n = 114, 69% boys), completed similar diagnostic, cognitive and academic assessments. Hierarchical multiple regression analyses identified significant predictors of word reading, spelling, and math computation performance in each sample. Results: Entered after IQ, semantic language, age at testing, and verbal working memory emerged as consistent predictors of achievement across academic subjects and samples. Visual-spatial working memory contributed to variance in math performance only. Symptom severity explained limited variance. Conclusions: We recommend evaluations of children with ADHD incorporate assessments of working memory and language skills. Classroom/academic interventions should accommodate reduced working memory and address any identified language weaknesses.

scholarly journals Resting‐State EEG Microstates Parallel Age‐Related Differences in Allocentric Spatial Working Memory Performance

2021 ◽  
Author(s):  
Adeline Jabès ◽  
Giuliana Klencklen ◽  
Paolo Ruggeri ◽  
Christoph M. Michel ◽  
Pamela Banta Lavenex ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Resting State ◽  
Cognitive Aging ◽  
Temporal Dynamics ◽  
Spatial Working Memory ◽  
Brain Activity ◽  
Memory Performance ◽  
Brain Regions ◽  
Age Related

AbstractAlterations of resting-state EEG microstates have been associated with various neurological disorders and behavioral states. Interestingly, age-related differences in EEG microstate organization have also been reported, and it has been suggested that resting-state EEG activity may predict cognitive capacities in healthy individuals across the lifespan. In this exploratory study, we performed a microstate analysis of resting-state brain activity and tested allocentric spatial working memory performance in healthy adult individuals: twenty 25–30-year-olds and twenty-five 64–75-year-olds. We found a lower spatial working memory performance in older adults, as well as age-related differences in the five EEG microstate maps A, B, C, C′ and D, but especially in microstate maps C and C′. These two maps have been linked to neuronal activity in the frontal and parietal brain regions which are associated with working memory and attention, cognitive functions that have been shown to be sensitive to aging. Older adults exhibited lower global explained variance and occurrence of maps C and C′. Moreover, although there was a higher probability to transition from any map towards maps C, C′ and D in young and older adults, this probability was lower in older adults. Finally, although age-related differences in resting-state EEG microstates paralleled differences in allocentric spatial working memory performance, we found no evidence that any individual or combination of resting-state EEG microstate parameter(s) could reliably predict individual spatial working memory performance. Whether the temporal dynamics of EEG microstates may be used to assess healthy cognitive aging from resting-state brain activity requires further investigation.

scholarly journals Testing Conclusions From Functional Imaging of Working Memory with Data From Acute Stroke

2007 ◽  
Vol 18 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Lisa E. Philipose ◽  
Hannah Alphs ◽  
Vivek Prabhakaran ◽  
Argye E. Hillis
Keyword(s):  
Working Memory ◽  
Acute Stroke ◽  
Functional Imaging ◽  
Right Hemisphere ◽  
Spatial Working Memory ◽  
Verbal Working Memory ◽  
Stroke Patients ◽  
Imaging Results ◽  
Cortical Stroke ◽  
The Right

Functional imaging studies indicate that the left hemisphere mediates verbal working memory, while the right hemisphere mediates both verbal and spatial working memory. We evaluated acute stroke patients with working memory tests and imaging to identify whether unilateral dysfunction causes deficits in spatial and/or verbal working memory deficits. While left cortical stroke patients had verbal working memory impairments (p< 0.003), right cortical stroke patients had both verbal (p< 0.007) and spatial working memory (p< 0.03) impairments, confirming functional imaging results. Patients with transient ischemic stroke and patients with non-cortical stroke did not have significant deficits in working memory in either modality.

scholarly journals Maintenance Mechanisms in Children’s Verbal Working Memory

2015 ◽  
Vol 6 (1) ◽  
pp. 16 ◽  
Author(s):  
Anne-Laure Oftinger ◽  
Valerie Camos
Keyword(s):  
Working Memory ◽  
Recall Performance ◽  
Age Groups ◽  
Verbal Working Memory ◽  
Concurrent Task ◽  
Verbal Information ◽  
Complex Span ◽  
Span Tasks ◽  
Joint Contribution

<p>Previous research in adults has indicated two maintenance mechanisms of verbal information in working memory, i.e., articulatory rehearsal and attentional refreshing. However, only three studies have examined their joint contribution to children’s verbal working memory. The present study aimed at extending this line of research by investigating the developmental changes occurring from 6 to 9 years old. In two experiments using complex span tasks, children of three different age groups maintained letters or words while performing a concurrent task. The opportunity for attentional refreshing was manipulated by varying the attentional demand of the concurrent task. Moreover, this task was performed either silently by pressing keys or aloud, the latter inducing a concurrent articulation. As expected, recall performance increased strongly with age. More interestingly, concurrent articulation had a detrimental effect on recall even in 6-year-old children. Similarly, introducing a concurrent attention-demanding task impaired recall performance at all ages. Finally, the effect of the availability of rehearsal and of attentional refreshing never interacted at any age. This suggested an independence of the two mechanisms in the maintenance of verbal information in children’s working memory. Implications for the development of rehearsal use and for the role of attention in working memory are discussed.</p>

scholarly journals Social Skills Intervention Participation and Associated Improvements in Executive Function Performance

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Shawn E. Christ ◽  
Janine P. Stichter ◽  
Karen V. O’Connor ◽  
Kimberly Bodner ◽  
Amanda J. Moffitt ◽  
...  
Keyword(s):  
Working Memory ◽  
Executive Function ◽  
Social Competence ◽  
Spatial Working Memory ◽  
Neurodevelopmental Disorder ◽  
Memory Task ◽  
Verbal Working Memory ◽  
Autism Spectrum ◽  
Mixing Costs ◽  
Adolescents With Asd

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social communication. It has been postulated that such difficulties are related to disruptions in underlying cognitive processes such as executive function. The present study examined potential changes in executive function performance associated with participation in the Social Competence Intervention (SCI) program, a short-term intervention designed to improve social competence in adolescents with ASD. Laboratory behavioral performance measures were used to separately evaluate potential intervention-related changes in individual executive function component processes (i.e., working memory, inhibitory control, and cognitive flexibility) in a sample of 22 adolescents with ASD both before and after intervention. For comparison purposes, a demographically matched sample of 14 individuals without ASD was assessed at identical time intervals. Intervention-related improvements were observed on the working memory task, with gains evident in spatial working memory and, to a slightly lesser degree, verbal working memory. Significant improvements were also found for a working memory-related aspect of the task switching test (i.e., mixing costs). Taken together, these findings provide preliminary support for the hypothesis that participation in the SCI program is accompanied by changes in underlying neurocognitive processes such as working memory.

scholarly journals Visuospatial bootstrapping: Binding useful visuospatial information during verbal working memory encoding does not require set-shifting executive resources

2018 ◽  
Vol 72 (4) ◽  
pp. 913-921 ◽  
Author(s):  
Clara Calia ◽  
Stephen Darling ◽  
Jelena Havelka ◽  
Richard J Allen
Keyword(s):  
Working Memory ◽  
Spatial Working Memory ◽  
Control Process ◽  
Verbal Working Memory ◽  
Long Term Memory ◽  
Executive Processes ◽  
Immediate Serial Recall ◽  
Task Load ◽  
Single Location ◽  
Visuospatial Information

Immediate serial recall of digits is better when the digits are shown by highlighting them in a familiar array, such as a phone keypad, compared with presenting them serially in a single location, a pattern referred to as “visuospatial bootstrapping.” This pattern implies the establishment of temporary links between verbal and spatial working memory, alongside access to information in long-term memory. However, the role of working memory control processes like those implied by the “Central Executive” in bootstrapping has not been directly investigated. Here, we report a study addressing this issue, focusing on executive processes of attentional shifting. Tasks in which information has to be sequenced are thought to be heavily dependent on shifting. Memory for digits presented in keypads versus single locations was assessed under two secondary task load conditions, one with and one without a sequencing requirement, and hence differing in the degree to which they invoke shifting. Results provided clear evidence that multimodal binding (visuospatial bootstrapping) can operate independently of this form of executive control process.

scholarly journals Effect of verbal working memory load during the oculomotor activity in visual search

2015 ◽  
Vol 8 (2) ◽  
pp. 21-35 ◽  
Author(s):  
B.B. Velichkovsky ◽  
A.I. Izmalkova
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Spatial Working Memory ◽  
Memory Load ◽  
Mutual Influence ◽  
Verbal Working Memory ◽  
Working Memory Load ◽  
Visual Spatial ◽  
Visual Spatial Working Memory ◽  
Oculomotor Activity

The structure of working memory has components responsible for the storage of verbal and visualspatial information; despite the fairly detailed study of the functions and mechanisms of their work, the question of their mutual influence is still open. Studies on the verbal working memory load influence on visual search performance (a task requiring the use of visual-spatial working memory resources) it was found that the load on the verbal working memory leads to increased efficiency of target detection. The results of the analysis of oculomotor activity during visual search also point out that the implementation of such tasks under verbal working memory load is accompanied by an increase in cognitive tension and of the degree of search automaticity. The results may indicate the interaction of verbal and visual-spatial working memory components that share non-specific cognitive resources.

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