There is currently little symptomatic therapy for Alzheimer's Disease (AD) and nothing effective for individuals with Frontotemporal dementia (FTD). However, neuromodulation with transcranial direct current stimulation (tDCS) has the potential to be a clinically effective therapy for both AD and FTD. The challenge now is to specify the parameters and conditions under which tDCS is most effective to transition from the laboratory to clinical medicine. tDCS studies typically report significant group effects despite the variability demonstrated among participants, with some showing clear, meaningful improvement, while others only show statistical improvement or none at all. These variable results may be related to the conventional stimulation intensity level of 2mA. The investigators predict that administering tDCS at 4.0 mA, a more significant number of participants would show a meaningful response, and those who improve at 2mA may improve even more from 4.0mA due to having a larger electric field produced. The investigators aim to test this hypothesis in people with Alzheimer's Disease.

Inclusion Criteria:

• Mild to Moderate AD
• Score between 18 and 25 on the MoCA
• Able to do the N-Back task during the initial screening

Exclusion Criteria:

• No history of stroke or TBI
• No shunts or metal in the body
• No history of significant heart disease, alcoholism and drug use