Modulation of Episodic Memory Using Theta Burst Stimulation (TBS)

The goal of this study is to evaluate the effect of white matter guided theta burst stimulation on episodic memory task performance in healthy older adults. The investigators aim to propagate the effect of theta burst stimulation from a superficial locus of stimulation (angular gyrus) to hippocampus and parahippocampal regions using white matter tract connection between these regions. Study activities and population group - for the study plans to recruit 20 healthy older adults who already have white matter scans acquired as part of another study performed by the Cabeza Lab at Duke University. Using tractography the exact site of stimulation on the cortical surface will be localized. An initial motor evoked potential (MEP) assessment will differentiate responders to theta burst stimulation from non responders. Responders will receive 1200 pulses of intermittent theta burst stimulation (iTBS) or sham stimulation to the angular gyrus while they perform the encoding portion of an episodic memory task. There after, they will perform retrieval piece of the task and data analysis will compare these performances.