tVNS for Cognitive Impairments in Community-Dwelling Elderly

Inclusion Criteria: (1) 65≤age≤75 years old; (2) years of education ≥1 year; (3) normal daily life ability; (4) total score of The Chinese version of Mini-Mental State Examination (MMSE) : Non-illiterate group (not graduated from elementary school)\> 14 points, elementary school group\> 19 points, middle school and above group\> 24 points). Exclusion Criteria: (1) People with obvious hearing, vision problems or communication difficulties; (2) People with obvious cognitive dysfunction (such as Alzheimer's disease); (3) People with serious medical diseases (such as heart disease, uremia, severe diarrhea) ; (4) In the stage of radiotherapy and chemotherapy; (5) People with serious neurological diseases (such as Parkinson's disease, infectious encephalopathy); (6) Patients with mental diseases (such as schizophrenia, depression, etc.); 7) Patients with substance abuse or alcohol dependence; (8) patients with implantable medical devices such as cardiac pacemakers; (9) patients with scars or inflammation on the ear skin.