A study investigating the effects of non-invasive electrical stimulation of deep brain structures on working memory, attention, and executive functions involved in everyday activities. Currently, there is no effective treatment for impairments in these functions. The study will evaluate the effects of non-invasive electrical stimulation in both healthy older adults and individuals with mild impairment of these functions.

The study combines magnetic resonance imaging (MRI) with non-invasive brain stimulation targeting deep brain structures. Its aim is to improve understanding of the neural mechanisms underlying these cognitive functions and their impairments, as well as to explore the mechanisms of non-invasive brain stimulation for potential future therapeutic applications.

Inclusion Criteria:

• normal cognitive performance as assessed by a cognitive screening for healthy subjects
• possible or probable MCI-LB or with PD-MCI, collectively called MCI-LBD, described as: presence of PD , and level II criteria for MCI (i.e. based on comprehensive neuropsychological examination), or the level II criteria for MCI , and at least two of four core DLB features including parkinsonism, visual hallucinations, attention/cognitive function fluctuation, and REM sleep behavioral disorder, or at least 1 core clinical feature and 1 indicative biomarker (probable MCI-LB).

Exclusion Criteria:

• Psychiatric disorders including major depression, major vascular lesions, or other brain pathologies that might present with cognitive decline.