40 Hz Transcranial Alternating Current Stimulation for Inducing Gamma Oscillations

Induction and Stabilization of Gamma Oscillations With 40 Hz Transcranial Alternating Current Stimulation in Healthy Elderly

This study aims to compare the efficacy of different 40 Hz tACS protocols in entraining gamma oscillations, which are linked to various cognitive functions and play a significant role in cognitive impairments like Alzheimer's disease. Specifically, it examines the effects of 40 Hz tACS applied to frontal brain regions versus fronto-temporal regions on gamma oscillations and working memory in healthy elderly individuals.

Inclusion Criteria:

• healthy elderly between 50-80 years of age
• normal or corrected to normal eye vision
• right-handed
• non-smokers
• at least 70 % accuracy in working memory training task

Exclusion Criteria:

• history of neurological or psychiatric disorders including seizures or epilepsy,
• Taking CNS, blood pressure and other medications
• having metal implants in the head and neck
• significant cognitive decline meassured by The Montreal Cognitive Assessment (MoCA)