Association of Transcranial Alternating Current Stimulation with Digital Cognitive Training for Cognitive Remediation in Older Adults

Our goals in this study are: * To investigate the feasibility and safety of transcranial direct current stimulation (tDCS) adjunctive to cognitive training (CT) in a cohort of individuals diagnosed with mild cognitive impairment (MCI), Subjective Cognitive Decline or Alzheimer's desease in it's initial phase (CDR 1). * To assess the efficacy of this combined intervention in modulating cognitive function, as measured by a comprehensive neuropsychological battery. * To explore the underlying neural mechanisms of this intervention by examining changes in event-related potentials (ERPs), specifically the N200 and P300 components, which are sensitive to cognitive processes and neural plasticity. * To identify potential peripheral biomarkers in serum that may correlate with cognitive decline and response to the intervention. * To determine whether the combined intervention can induce lasting changes in neurophysiological markers, as assessed by repeated ERP measurements. * To examine the relationship between the observed cognitive improvements, alterations in neurophysiological measures, and changes in serum biomarker levels, with the aim of elucidating the biological mechanisms underlying the intervention's effects.