A group of 20 cognitively intact younger participants (age 21-35), a group of 20 cognitively intact older participants (age 55+) and an age-matched group of 20 MCI/mild AD participants will be enrolled in the brain stimulation study with behavioral assessments at baseline and post-intervention. All participants will perform a laboratory-based memory task and an autobiographical memory task, followed by the autobiographical interview after the tACS intervention. Each participant will undergo three experimental sessions, applying 20-minute gamma tACS stimulation, theta tACS stimulation or an active sham (control) to the left angular gyrus. Before, during, and after the brain stimulation scalp high-density 257-channels EEG will be recorded to characterize and differentiate brain activity and regional interactions in the three independent groups.
The overall objective of this project is to examine the effects of non-invasive brain stimulation on episodic memory performance