Stimulating the Aging Brain Using Brain and Sensory Stimulation

Stimulating the Aging Brain: Noninvasive Brain and Sensory Stimulation Strategies in Aging

The goal of this project is to investigate whether transcranial electrical stimulation and sensory stimulation affect language outcomes in individuals with primary progressive aphasia (PPA). The main questions it aims to answer are:

Does transcranial alternating current stimulation (tACS) affect verbal short-term memory (STM) in individuals with PPA? Does a single session of multisensory stimulation affect verbal STM in individuals with PPA? Researchers will compare active tACS to sham tACS (a fake stimulation condition) to see if active tACS improves verbal STM. Researchers will compare pre-multisensory stimulation to post-stimulation performance to see if multisensory stimulation improves verbal STM.

Participants will:

Undergo EEG, MRI (anatomical and functional) May complete a cognitive exam Undergo tACS over 3 separate sessions Undergo multisensory stimulation Complete language tasks before, during and/or after stimulation

The primary objective of the current project is to examine the effects of tACS and multisensory stimulation on verbal STM outcomes in individuals with PPA. The selection of parameters will be guided on the basis of oscillatory brain activity using language task-based or task-free EEG paradigms. Neuroimaging (MRI and functional MRI) will guide spatial targets of tACS. A secondary objective is to explore sources of individual variability in response to stimulation and whether these factors could offer insight into disease progression. This proof-of-concept, pilot project will generate essential preliminary data to help refine hypotheses for future clinical trials aimed at assessing the efficacy of these intervention strategies in predicting and treating (as in delaying) disease progression.

Inclusion Criteria:

• Clinical exam supports diagnosis of PPA and/or MCI with no report of difficulty functioning in basic or instrumental activities of daily living.
• Completed clinical cognitive exam within 6 months of study baseline visit OR neuropsychological research battery within 6 months of study baseline visit.

Exclusion Criteria:

• Evidence of dementia at baseline
• Known history of neoplasm, symptomatic stroke, moderate to severe traumatic brain injury, or other significant neurologic event
• Age <45 years.
• Evidence of severe psychiatric illness (e.g., bipolar disorder, schizophrenia).
• Presence of cardiac stimulators or pacemakers
• Any other implants near the scalp or in the eye
• Contraindications to MRI or stimulation
• Pregnancy
• History of ongoing or unmanaged seizures
• History of dyslexia or other developmental learning disabilities