BACKGROUND Cognitive decline in older adults, especially those who develop Mild Cognitive Impairment and Alzheimer's Disease, currently has limited options of pharmacological treatments, with modest efficacy. Digital Cognitive Training (DCT) and Transcranial Alternating Current Stimulation (tACS) are two promising tools for cognitive remediation in this population. In this exploratory study, we investigate feasibility, tolerability and preliminary effects of the association of both interventions in older adults with cognitive complaints. METHODS Older adults with cognitive complaints are being enrolled for this study, which comprises 5 daily sessions of 30 minutes of DCT using the BrainHQ platform while simultaneously receiving theta tACS (6Hz, 1.6mA) targeting the Left Dorsolateral Prefrontal Cortex.