# Synchronizing Oscillatory Brain Activity to Treat Post-Stroke Aphasia

> **NIH NIH R21** · MEDICAL COLLEGE OF WISCONSIN · 2024 · $428,883

## Abstract

PROJECT SUMMARY/ABSTRACT
Transcranial alternating current stimulation (tACS) is increasingly used to enhance perceptual and cognitive
performance in healthy individuals and in individuals with neurological and psychiatric disorders. But even after
>8000 publications and strong evidence suggesting positive effects, clinical applications of tACS to improve
language outcomes in stroke survivors with aphasia (SWA) are few and far between. Little guidance is available
from the existing literature to effectively plan tACS treatment protocols in SWA.
The selection of tACS parameters is complicated by large underlying anatomical and functional heterogeneity
after stroke. Given this heterogeneity, our overarching hypothesis is that tACS efficacy will depend on stimulation
target selection, frequency and effectiveness of electric field coverage at individual patient level. Our proposed
project seeks to examine the effects of individualized selection of tACS targets and frequency (Aim 1), based
on detailed analyses of lesion location, residual functional activity, and residual brain oscillatory activity on
phonological short-term memory (pSTM) performance in chronic SWA. We hypothesize that individualized tACS
will enhance the size and reliability of tACS response. This project is motivated by individual variability that we
observed in our preliminary data from 9 SWA. Independent of Aim 1, we will also explore how stroke
characteristics influence residual functional and oscillatory brain activity underlying pSTM (Aim 2).
Our project fits perfectly within the scope of the R21 Exploratory/Developmental grant because it is at “early and
conceptual stages” and is within one of NIDCD’s scientific foci—treating “disorders of human communication”.
Notable innovations of the proposed project are our novel use of (1) multimodal structural, functional and
electrophysiological techniques to optimize tACS parameters in individual SWA, and (2) individualized electric
field models to optimize tACS electrode arrangements, both in service to increase the efficacy of tACS.
While ideally aphasia therapy would be ecologically valid and would enhance functional communication
outcomes, the proposed use of a lab-based controlled task and focus on pSTM is needed at this stage to gain a
better understanding of the effects of tACS in SWA. This knowledge will facilitate future use of tACS as an
adjunctive treatment to boost functional outcomes. Presently, a proof-of-concept study is crucial to establish a
sound methodological basis for developing effective neurorehabilitation strategies using tACS in SWA.

## Key facts

- **NIH application ID:** 11035400
- **Project number:** 1R21DC022376-01
- **Recipient organization:** MEDICAL COLLEGE OF WISCONSIN
- **Principal Investigator:** Priyanka Shah-Basak
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $428,883
- **Award type:** 1
- **Project period:** 2024-09-19 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11035400

## Citation

> US National Institutes of Health, RePORTER application 11035400, Synchronizing Oscillatory Brain Activity to Treat Post-Stroke Aphasia (1R21DC022376-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/11035400. Licensed CC0.

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