These assessments will include measures of upper extremity motor assessments, standard stroke scales, and measures of activities of daily living.

A functional magnetic resonance image will be collected.

EEG electrodes will be attached to the subject's scalp using a standard, commercially available electrode cap. Proper electrode placement is made according to the international 10-20 system, ensuring complete electrode coverage over sensorimotor cortex.

To compare the percent signal change in the functional MRI activations before and after functional stimulation.

The 9-HPT is a quick and easy to administer tool for screening fine motor problems in participants. It is a timed test in which nine pegs are inserted and removed from nine holes in the pegboard with each hand. Measured at 5 time points over the length of the study.

The MAL is a structured interview developed to assess the use of the more affected upper extremity (UE) in real-world daily activities. Assessed at 5 time points over the length of the study. The Amount of Use scoring is as follows (intermediate scores are possible, 0.5 between each whole number):

• 0 - Did not use my weaker arm (not used).
• 1 - Occasionally used my weaker arm, but only very rarely (very rarely).
• 2 - Sometimes used my weaker arm but did the activity most of the time with my stronger arm (rarely).
• 3 - Used my weaker arm about half as much as before the stroke (half pre-stroke).
• 4 - Used my weaker arm almost as much as before the stroke (3/4 pre-stroke).
• 5 - Used my weaker arm as often as before the stroke (same as pre-stroke).

The MAL is a structured interview developed to assess the use of the more affected upper extremity (UE) in real-world daily activities. Assessed at 5 time points over the length of the study. The Quality of Movement was scored as follows (intermediate scores 0.5 between whole numbers are possible):

• 0 - The weaker arm was not used at all for that activity (never).
• 1 - The weaker arm was moved during that activity but was not helpful (very poor).
• 2 - The weaker arm was of some use during that activity but needed some help from the stronger arm or moved very slowly or with difficulty (poor).
• 3 - The weaker arm was used for the purpose indicated but movements were slow or were made with only some effort (fair).
• 4 - The movements made by the weaker arm were almost normal, but were not quite as fast or accurate as normal (almost normal).
• 5 - The ability to use the weaker arm for that activity was as good as before the stroke (normal).

The MAS measures spasticity where 0 is no increase in muscle tone to 4 where affected part is in rigid in flexion or extension. Assessed at 5 time points over the length of the study.

Hand Grip Strength will be assessed using a dynamometer. Measured at 5 time points over the length of the study.

The CES-D is a self-report scale and includes 20 items that survey mood, somatic complaints, interactions with others, and motor functioning in the past week. Total possible score 0-60, with the higher score indicating more symptoms of depression. Assessed at 5 time points over the length of the study.

Total of all reporting groups

Subjects randomized to this experimental group will be asked to complete the active FES intervention which include EEG guided muscle stimulation. Participation will include behavioral assessments, functional magnetic resonance imaging, functional electric stimulation (FES) treatment, and EEG.

The Stroke Impact Scale, or SIS, was created to assess changes in impairments, activities and participation following a stroke. Scores on the SIS will provide an index of clinically "meaningful" change representing the change in the patient's mental and physical abilities concurrent with their performance on the verbal fluency and memory tasks. The 4 physical function domains (strength, hand function, activities of daily living (ADL)/instrumental activities of daily living (IADL), and mobility) will be collapsed to a physical function subscale. All domain scores range from 0 to 100 with 100 being the best.

Some participants did not provide data at all timepoints.

EEG was recorded in microvolts (µV) from electrodes C4/C3 during periods of left arm imagery and right arm imagery. EEG Response strength is defined as the spectral power in the mu + beta frequency band (8-30 Hz), averaged over the BCI trials. For each participant and time point, a ratio was computed: Ratio = Power_Left Imagery / Power_Right Imagery.

Some participants did not provide data at all time points

To compare the percent signal change in the functional MRI activations before and after functional stimulation.

Some participants did not provide data at all time points

The 9-HPT is a quick and easy to administer tool for screening fine motor problems in participants. It is a timed test in which nine pegs are inserted and removed from nine holes in the pegboard with each hand. Measured at 5 time points over the length of the study.

Some participants did not provide data at all time points.

The MAL is a structured interview developed to assess the use of the more affected upper extremity (UE) in real-world daily activities. Assessed at 5 time points over the length of the study. The Amount of Use scoring is as follows (intermediate scores are possible, 0.5 between each whole number):

• 0 - Did not use my weaker arm (not used).
• 1 - Occasionally used my weaker arm, but only very rarely (very rarely).
• 2 - Sometimes used my weaker arm but did the activity most of the time with my stronger arm (rarely).
• 3 - Used my weaker arm about half as much as before the stroke (half pre-stroke).
• 4 - Used my weaker arm almost as much as before the stroke (3/4 pre-stroke).
• 5 - Used my weaker arm as often as before the stroke (same as pre-stroke).

Some participants did not provide data at all timepoints.

The MAL is a structured interview developed to assess the use of the more affected upper extremity (UE) in real-world daily activities. Assessed at 5 time points over the length of the study. The Quality of Movement was scored as follows (intermediate scores 0.5 between whole numbers are possible):

• 0 - The weaker arm was not used at all for that activity (never).
• 1 - The weaker arm was moved during that activity but was not helpful (very poor).
• 2 - The weaker arm was of some use during that activity but needed some help from the stronger arm or moved very slowly or with difficulty (poor).
• 3 - The weaker arm was used for the purpose indicated but movements were slow or were made with only some effort (fair).
• 4 - The movements made by the weaker arm were almost normal, but were not quite as fast or accurate as normal (almost normal).
• 5 - The ability to use the weaker arm for that activity was as good as before the stroke (normal).

Some participants did not provide data at all timepoints.

The MAS measures spasticity where 0 is no increase in muscle tone to 4 where affected part is in rigid in flexion or extension. Assessed at 5 time points over the length of the study.

MAS data were not collected in order to reduce participant burden associated with completing multiple assessments during study visits. The protocol was not amended to reflect this.

Hand Grip Strength will be assessed using a dynamometer. Measured at 5 time points over the length of the study.

Some participants did not provide data at all timepoints.

The CES-D is a self-report scale and includes 20 items that survey mood, somatic complaints, interactions with others, and motor functioning in the past week. Total possible score 0-60, with the higher score indicating more symptoms of depression. Assessed at 5 time points over the length of the study.

CES-D data were not collected in order to reduce participant burden associated with completing multiple assessments during study visits. The protocol was not amended to reflect this.

Subjects randomized to this experimental group will be asked to complete the active FES intervention which include EEG guided muscle stimulation. Participation will include behavioral assessments, functional magnetic resonance imaging, functional electric stimulation (FES) treatment, and EEG.