Lewy body diseases (LBDs) represents a group of neurodegenerative disorders characterized by the abnormal accumulation of aggregates of α-synuclein protein leading to the formation of Lewy bodies (LB) and Lewy neurites resulting in cell death. LBDs consists of two major clinical entities - Parkinson's disease (PD) and dementia with LB (DLB). Vast majority of patients with LBDs either already have mild cognitive impairment (MCI) at the time of the diagnosis or will develop it during the course of the disease. Language dysfunctions in LBDs patients with MCI are often unrecognized, which are difficult to treat, but even subtle changes might lead to impairment of social and occupational functioning with profound effect on their quality of lives. Current pharmacological or surgical strategies are effective for tackling the motor issues of LBDs with very limited effects on other symptoms such as language dysfunctions. Therefore, non-pharmacological approaches are gaining more attention. One of these non-pharmacological strategies is the use of noninvasive brain stimulation (NIBS) techniques that are able to modulate the brain functions with the effects on human nervous system plasticity. In this proposed project the investigators aim to first describe specific alterations in the language domain in LBDs patients with MCI as compared to healthy controls (HC) and identify the neural underpinnings of these changes using novel combination of advanced multimodal imaging techniques and various analytical methods. Secondly, the investigators aim to use NIBS as a supervised and individualized home-based therapeutical approach to tackle the language dysfunctions.