Home-Based Brain Stimulation for Motoric Cognitive Risk Syndrome

Inclusion Criteria: * Men and women * Age 65-90 years * Subjective cognitive complaints as defined by a 'Yes' response to "Do you feel that you have more problems with memory than most?" or a 'No' response to "is your mind as clear as it used to be?" * Montreal Cognitive Assessment (MoCA) score ≥21 * Slow gait speed as measured by averaging two 4-Meter walks and defined as a usual walking speed one standard deviation below age and sex-adjusted means. * Absence of significant disability as defined by the ability to walk over the instrumented gait mat unassisted (e.g., able to walk without any walking aids for at least 2 minutes non-stop) and preserved activities of daily living as defined by a score of less than 9 on the Functional Activities Questionnaire. * Identification of an eligible informant * Identification of a willing and able tDCS-administrator; i.e., a study partner to lead the administration of home-based transcranial direct current stimulation (tDCS) * Access to reliable WiFi in the participant's home Exclusion Criteria: * Formal education less than the 8th grade * Previous physician diagnosis of dementia * Any current diagnosis of a major psychiatric disorder (e.g., schizophrenia, bipolar disorder, major depressive disorder) * Evidence of moderate-to-severe depressive symptoms defined by a score of ≥9 on the 15-item Geriatric Depression Scale * History of head trauma resulting in prolonged loss of consciousness * History of fainting spells of unknown or undet…