Non-invasive Brain Stimulation for Cognitive and Motor Dysfunction in Dementia

Change in Rey Auditory Verbal Learning Test (RAVLT) Total Recall

This test is designed to evaluate verbal memory in those 16 years of age and older. It can be used to evaluate the nature and severity of memory dysfunction and to track changes in memory function over time. Total recall is measured by the total number of words out of 15 the participant is able to recall. Scores range from 0 to 15.

Change in Dual Task Cost to Gait

This measure is captured by Mobility Lab™ (APDM Inc) software while the participant is walking with sensors at a) normal speed (speed for single task) and b) walking while counting backwards by 3's or 1's (speed dual task). The formula for cost of the dual task to gait is: (speedsingletask-speeddualtask)/speedsingletask)\*100). Range for dual task cost is as follows: High Risk for falls \> 0.2, Moderate Risk for falls \<= 0.2, Low Risk \< 0.1.

Change in Functional Activity Questionnaire

This is a 10-item scale to measure functional status via independent activities of daily living. Each item is a functional activity, and the caregiver/informant rates the participant's ability using the following scoring system: * Dependent = 3 * Requires assistance = 2 * Has difficulty but does by self = 1 * Normal = 0 * Never did \[the activity\] but could do now = 0 * Never did and would have difficulty now = 1 The scores are summed (range 0-30). Cut-point of 9 (dependent in 3 or more activities) is recommended to indicate impaired function and possible cognitive impairment. This test will be used to track functional status over the course of the intervention and follow-up.

Change in Montreal Cognitive Assessment (MoCA) total score, memory and executive subscores

The Montreal Cognitive Assessment (MoCA) is designed as a rapid screening instrument for mild cognitive dysfunction. It assesses different cognitive domains. The total possible score is 30 points; a score of 26 or above is considered normal. Severity of impairment can be determined with the following scores: 18-25 = mild cognitive impairment, 10-17= moderate cognitive impairment, and less than 10= severe cognitive impairment. The maximum total score is 30 and the minimum total score is 0 points. The memory and executive subscales are each on a range of 0 to 5 points.

Average E-field normal component (En) for left angular gyrus and prefrontal cortex

From magnetic resonance imaging, an E-field normal component value will be computer for each brain voxel. From those measurements an average En value will be computed in the anatomically-defined left AG (i.e., Brodmann areas 39/40), and separately the left PFC (i.e., Brodmann areas 39/40). This outcome of average En will provide information on the amount of current each participant receives during the intervention in the targeted areas.

Change in Adjusted Trail Making Test performance

The Trail Making Test (TMT) is a test of visual attention and task switching, which consists of two parts (A \& B). It is scored by timing how long it takes to complete each part of the test, separately. The maximum time allowed for part A or part B is 300 seconds. Age and education adjusted norms are available to determine standard scores. The Adjusted performance is calculated by subtracting the time it takes to complete part A (in seconds) from the time it takes (in seconds) to complete part B. This is a measure of executive functioning and also has age and education adjusted norms.