Research

Our research integrates TMS, neuroimaging, and cognitive assessment to understand the aging brain. We study mild cognitive impairment, Alzheimer's disease, and cognitive aging — with a focus on image-guided therapeutic protocols and early biomarkers of decline.

Research Themes

Memory and cognition enhancement

Memory & cognition enhancement

Using neuroimaging and individualized targeting, we are developing image-guided TMS protocols to enhance memory in older adults and those at risk for Alzheimer's disease. By personalizing stimulation targets with resting-state connectivity, hippocampal anatomy, and white-matter pathways, we aim to move beyond one-size-fits-all protocols and improve therapeutic outcomes.

Examples: Chen et al. 2022 (PNAS); Chou et al. 2020 (Neurobiology of Aging).

Plasticity and brain health

Plasticity & brain health

Using TMS probes of cortical plasticity — including homeostatic metaplasticity, short afferent inhibition, and motor thresholds — we are characterizing brain health across aging. These measures hold promise as early biomarkers of cognitive decline and predictors of therapeutic response.

Examples: Sundman et al. 2024 (Aging Brain); Sundman et al. 2020 (Brain Communications).

Precision neuromodulation

Precision neuromodulation

Combining neuronavigation, white-matter-tract targeting, electric-field modeling, and accelerated TMS protocols, we are advancing the field toward more precise and individualized stimulation. Ongoing work extends these approaches toward closed-loop stimulation guided by real-time brain signals.

Examples: Chen et al. 2022 (PNAS); Zhang et al. 2025 (Biological Psychiatry).

Methodological advances

Methodological advances

Using spatially-resolved EEG, connectomic analyses, and novel cognitive assessments, we are developing new tools to measure TMS-induced brain changes and detect subtle aging-related decline. This work supports both our therapeutic program and the broader field.

Examples: Frank et al. 2026 (Frontiers in Human Neuroscience); Liu et al. 2025 (Frontiers in Aging Neuroscience).

Cross-population applications

Cross-population applications

Extending TMS therapeutics beyond cognitive aging, we collaborate with clinical partners across diverse populations — including Parkinson's disease, stroke aphasia, post-chemotherapy cognitive impairment, and carotid disease — to advance neuromodulation as a translational tool.

Examples: Chou et al. 2015 (JAMA Neurology); Kielar et al. 2022 (Clinical Neurophysiology).

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Current Research Support

R01 NIH/NIA

Hippocampal Plasticity via Repetitive TMS

PI: Ying-hui Chou · 05/2020 – 01/2027

McKnight

Targeting Sleep to Preserve Memory: Accelerated Theta Burst Stimulation and At-Home Sleep EEG to Enhance Cognitive Health in Aging

PIs: Ying-hui Chou and Christian Agudelo · 07/2026 – 06/2028

Developmental AZ Alzheimer's Consortium

Precision Neuromodulation for Cognitive Aging: Leveraging BrainAGE to Predict and Personalize rTMS Response

PI: Yilin Liu · 07/2026 – 06/2028

Mini-Grant W. A. Franke Honors College

Investigating the Potential of Ketone Supplementation as a Primer for Neural Plasticity

PIs: Shraddha Dwivedi and Carol Chen · 03/2026 – 02/2028

Pilot AZ Alzheimer's Consortium

Arizona Alzheimer's Consortium Match Projects

PI: Lee Ryan · Co-Investigator · 07/2018 – 06/2027

DoD

TMS of the Default Mode Network for Sleep

PI: William Scott Killgore · Co-Investigator · 09/2024 – 08/2027

Merit VA

Carotid Disease in Cognitive Impairment & Dementia

PI: Wei Zhou · Co-Investigator · 10/2024 – 09/2028

U01 NIH/NIBIB

Transcranial Acoustoelectric Imaging of Neuronal Currents

PI: Russell Witte · Co-Investigator · 09/2020 – 06/2027

R21 NIH/NINDS

EM Neuromodulation of Slow-Wave Activity & the Glymphatic System

PI: Nan-kuei Chen · Co-Investigator · 07/2024 – 06/2026

Past Research Support

17 completed grants — scroll within the panel below to see all.

Period Title Role Agency Type
04/2022 – 03/2024 Interleaved TBS-fMRI for Spaced Hippocampal Stimulation (Modeling Dose-Response in Amnestic MCI) PI NIH/NIA R21
09/2018 – 01/2025 Explore-Exploit Decision Making in Older Adults (PI: Robert Wilson) Co-I NIH/NIA R56/R01
07/2023 – 06/2025 Arizona Alzheimer's Consortium Project PI AZ Alzheimer's Consortium Developmental
02/2021 – 06/2021 MRI-Compatible TMS System — Concurrent TMS-fMRI Method Development PI University of Arizona, RII
07/2018 – 12/2019 Non-Invasive Magnetic Brain Stimulation Protocol for Mild Cognitive Impairment PI BIO5 Institute, UA
07/2017 – 06/2019 TMS and fMRI to Assess Risk of MCI-to-Dementia Conversion PI NIH/NIA (Sub-Award P30 AG019610) Pilot
11/2020 – 06/2021 Using TMS to Detect Deficits of Cholinergic System in the Aging-MCI-AD Continuum PI UA Faculty Seed Grant
07/2018 – 12/2021 Treatment of Post-Chemotherapy Cognitive Impairment with TMS (PI: Phillip Kuo) Co-I UA Cancer Center Pilot
10/2019 – 09/2020 4D Transcranial Acoustoelectric Imaging (PI: Russ Witte) Co-I NIH R56
07/2017 – 06/2019 Neural Substrates of Explore-Exploit Decisions in Old Age (PI: Robert Wilson) Co-I NIH/NIA (Sub-Award P30 AG019610) Pilot
10/2020 – 09/2022 Transcranial Magnetic Stimulation of the Default Mode Network to Improve Sleep (PI: Scott Killgore) Co-I DoD, Discovery Award
09/2011 – 05/2016 Neuroimaging of Visual Attention in Aging (PI: David Madden) Key Personnel NIH/NIA R01
09/2012 – 06/2017 Dorsal Cingulate Activity and Cognitive Decline in Late-Life Depression (PIs: Lihong Wang and David Madden) Key Personnel NIH/NIMH R01
07/2012 – 12/2014 Environments as Smoking Cues: Imaging Brain Substrates, Developing New Treatments (PI: Joseph McClernon) Key Personnel NIH/NIDA R21
07/1984 – 04/2015 Behavior and Physiology in Aging (PI: Harvey Cohen) Postdoc Trainee NIH/NIA T32
09/2008 – 07/2013 Developing Interventions to Improve Function in Seniors with Comorbid Conditions (PI: Heather Whitson) Postdoc Fellow NIH/NIA K23
2007 Effect of rTMS on Cortical Excitability in Patients with Epilepsy Co-I Changhua Christian Hospital, Taiwan