# Disruption of verbal working memory brain network in aphasia

> **NIH NIH F32** · GEORGETOWN UNIVERSITY · 2020 · $19,637

## Abstract

PROJECT SUMMARY/ABSTRACT
 Post-stroke language difficulties (aphasia) are usually accompanied by impairments in working memory
(WM), a cognitive system critical to daily functioning. WM plays an important role in language processing by
temporarily storing and keeping information active for further processing. Post-stroke WM impairments have
been suggested to affect language abilities and recovery in people with aphasia. However, the nature of the WM
impairments in people with aphasia has remained controversial.
 Two mechanisms have been proposed for maintenance of information in verbal working memory (VWM): an
articulatory rehearsal process relying on the interactions between left premotor and inferior parietal cortex, and
a non-articulatory mechanism, the nature of which has remained controversial. The non-articulatory mechanism
has been suggested to be an attentional process relying on the interactions of prefrontal attentional regions with
WM stores in the brain. Our recent lesion-symptom mapping study on left-hemisphere stroke survivors showed
that, depending on task demands, maintenance of verbal information relies on either auditory or articulatory brain
regions. While lesions to the superior temporal gyrus disrupted performance under lower demands, suggesting
reliance on auditory processes, lesions to sensorimotor cortex disrupted performance under higher demands
suggesting reliance on articulatory rehearsal. Some deep white matter regions were also implicated in each task.
These results clearly demonstrate a dissociation in the brain structures used for VWM maintenance under
different task demands, but do not provide a complete picture of how strokes disrupt VWM. Since WM relies on
a network of interconnected brain regions, VWM impairment likely results in part from structural disconnections
and disrupted functional connectivity within the VWM network. However, the contributions of disconnections in
VWM networks to VWM difficulties after left-hemisphere stroke has not previously been examined.
 This study of chronic left hemisphere stroke survivors with aphasia will identify the structural (Aim 1) and
functional disconnections (Aim 2) underlying VWM deficits through integration of behavioral testing with structural
connectome-symptom mapping and functional connectivity analyses (NIDCD Voice, Speech, and Language
Program: Language mission areas). The main hypothesis is that post-stroke VWM impairments relate to
structural disconnections and/or disrupted functional connectivity between bilateral prefrontal and inferior parietal
regions, with a) auditory processing areas under lower task demands, and b) articulatory motor areas under
higher task demands. Using data currently being collected in Dr. Turkeltaub’s lab, I will perform structural
connectome-based lesion-symptom mapping and resting-state functional connectivity analyses to determine
structural and functional disconnections that underlie VWM deficits. A knowledge of the cognitive an...

## Key facts

- **NIH application ID:** 10154184
- **Project number:** 1F32DC019014-01A1
- **Recipient organization:** GEORGETOWN UNIVERSITY
- **Principal Investigator:** Maryam Ghaleh
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $19,637
- **Award type:** 1
- **Project period:** 2020-11-01 → 2021-01-24

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10154184

## Citation

> US National Institutes of Health, RePORTER application 10154184, Disruption of verbal working memory brain network in aphasia (1F32DC019014-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10154184. Licensed CC0.

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