Memory and cognitive declines are associated with normal brain aging but are also precursors to dementia, in particular the so called the pandemic of the century, Alzheimer's disease. While currently there is no cure or "vaccine" against dementia, there are hopes to delay the onset of the disease by living a brain-healthy life style. The proposed research offers a novel approach to prevent dementia and age-related cognitive disorders.

We propose to use our developed brain fitness APP for the aging population with dementia. The proposed APP is based on the premise of brain plasticity, and targets the brain functions that are declining with normal aging and dementia. In a pilot study, we showed very positive effects of our custom designed brain exercises to strengthen left-right side brain connectivity in older adults when used regularly. Leveraging our previous design, we have developed an end-user product with additional features and enhanced user interface and user experience that will allow it to be used for neuro-cognitive rehabilitation by an individual without supervision The proposed APP will be tested on 30 individuals with cognitive impairment.

Additionally, participants can receive an optional electrical stimulation called transcranial alternating current stimulation. This applies an alternating current to a person's brain by two electrodes placed on the scalp. The participants, who choose this option, will receive simultaneous stimulation during the brain exercise tutored sessions. Studies have shown that simultaneous application of the electrical stimulation and cognitive exercises further enhances the cognitive function by boosting the working memory improvement. Thus, this may lead to further improvements from any potential positive effects of the brain exercises.

We anticipate the frequent use of the proposed APP will help to slow and even reverse the progression of the cognition decline in individuals with mild cognitive impairment or dementia.

The research is on the frequent use of our designed APP (for iPADs) that contains a series of our recently developed brain exercises that contains a series of our recently developed brain exercises, including orientation, associative memory, word-image association, recall memory, etc. Participant can receive an optional electrical stimulation called transcranial alternating current stimulation (tACS) simultaneously during the brain exercise tutor sessions.

Each participant will have a dedicated tutor for Brain Exercises with three scheduling options:

A) 5 days/week, 2 sessions/day each 30 min) for a period of 4 weeks, B) 3 days/week, 2 sessions/day each 30 minute for a period of 8 weeks, C) Remote program, 5 days/week, 40min/day for a period of 4 weeks (this option is not available for participants receiving tACS).

Inclusion Criteria:

• Age: 20+ years
• Have a score of 7≤ MoCA ≤ 25
• Being diagnosed with either mild cognitive impairment (MCI) or mild/moderate stage of Alzheimer's.
• Except the MCI/Alzheimer's diagnosis, have no known or diagnosis of major depression, bipolar disorder, schizophrenia, mood disorder, Parkinson's disease, Huntington disease, ALS, MS, and/or any other neurological disorder.
• Reading/writing fluency in English