Demographics of participants.

The data are shown in Mean±SD. Numbers of subjects are shown in brackets. AD, patients with Alzheimer's disease; Old, healthy older adults; Young, young adults; MMSE, mini mental state examination; CDR, clinical dementia rating scale; HIS, Hachinski ischemic scale; SDMT, symbol digital modalities test; Picture recall: 5 minutes delayed recognition of 10 pictures.a, 2 AD and 4 healthy older adults did not have CDR;b, Depression score in young adults was derived from Beck Depression Inventory, and it was derived from Geriatric Depression Scale in the older adults and AD patients;*, Group difference is significant when compared to healthy young adults, p#, Group difference is significant when compared to healthy older adults, p