Bilateral Brain Dynamics in Cognition and Aging

Study Summary

This project is focused on the gap in understanding of bilateral brain interactions and their role in helping normative and clinical elderly populations maintain cognitive health. The investigator will focus on investigating this neural mechanism of these interactions and promoting them with a precise application of TMS, in order to test the hypothesis that excitatory interactions between the hemispheres can provide positive outcomes for patients with pre-clinical AD (amnestic Mild Cognitive Impairment or MCI-AD). In Session 1, the investigator will establish the spatial specificity of bilateral brain mechanisms with combination of behavior, TMS, and structural neuroimaging in cortical sites known to be active during memory encoding. In Session 2, the investigator will establish the underlying dynamics of interhemispheric communication using a novel combination of TMS and electroencephalography (EEG) to establish the coordinated activity between the hemispheres; Lastly, in Session 3, the investigator will use the TMS entraining parameters delineated in Aim 2 to promote specific cross-hemispheric communication, applied to participants performing a Picture Encoding task, a general task of memory performance. The outcome of these studies will allow our group to evaluate the strength of this brain stimulation protocol in alleviating age-related and dementia-related cognitive decline, and enable development of novel treatment protocols for dementia in elderly cohorts.

Primary Outcome

This will be examined using a Picture Encoding (PE) task in healthy older adults, which will allow identification of spatial brain targets based on the structural pathways connecting left and right DLPFC, ultimately relating the integrity of these pathways based on PE task performance. This Primary Outcome measure will therefore be performance scores (% correct) on this PE task.

Interventions

• DEVICE TMS