To increase the feasibility of this project, the inclusion criteria of PWDs are made to reflect the recruiting site reality, including: (1) age being older than 60 years old; (2) having a primary FCG or a secondary FCG who can provides sufficient information and assistant for the PWD; co-residence is not required; (3) PWDs are those with cognitive impairment confirmed by the primary or secondary FCG or participating neurologists. The exclusion criteria of PWDs include: (1) acute illnesses, impaired sensory symptoms (hearing loss and severe visual problems); (2) acute agitation which requires emergency treatment; (3) chronic alcohol abuse or use of drugs which possibly affect central nervous system functions; (4) presence of major psychiatric disorders within the last 2 years; (5) neurological or systemic illness (e.g. delirium, hypoxia, or unstable thyroid dysfunction); (6) no primary FCG or secondary FCG.