Brain State-dependent Stimulation to Improve Movement

9-hole peg test (9-HPT) is a manual dexterity measure in which a participant must place 9 pegs in board with 9 holes, and remove all 9 pegs upon the insertion of all 9 pegs. This is completed with one peg at a time, and only one hand is used. For our study, only the right hand was used. The performance is estimated as the time required to complete the task (seconds). A lower time in seconds is indicative of a better score. For percent change in performance, a higher positive percent is indicative improved performance.

Motor cortical excitability is measured by electromyography using MEPs (motor evoked potentials) elicited by TMS (Transcranial magnetic stimulation) to a motor hotspot determined before collection of baseline (baseline occurs before intervention) MEP (motor evoked potential) collection. It was assessed in session 1, 3, 4, 5, 6, and 7, although only session 6 is reported here. An increase in MEPs (motor evoked potentials) is indicative of increased cortical excitability. A positive increase in MEP (motor evoked potential) percent change is indicative of increased cortical excitability.

Resting-state connectivity of low frequency BOLD (blood oxygenation level dependent) fluctuations for a seed at the PPC (posterior parietal cortex). The original analysis was a time-series correlation (Pearson's R) of resting state fMRI data between two regions of interest. The Z-score a Fisher's r-to-z transform. 0 for the Z value means that the pearson's correlation was also 0, positive means positive correlation and negative means it was a negative correlation. Therefore, standard deviations above the mean represented greater connectivity between the regions of interest. There were no clinically relevant thresholds to consider. The two time points being compared were scans from session 2 and session 7.

Parietal-frontal cortical grasping network defined by BOLD change during precision force-tracking task. t-test statistics were acquired for BOLD activation (estimated with univariate GLMs within each individual) from scans pre and post (session 2 and 7) with free surfer software. We ran univariate GLMs for each session for each individual that gave regression coefficients (beta values) for each voxel. We calculated a t-stat for each of those beta-values (each person and session we have a t-stat for our contrast of interest at each voxel). We averaged these across region of interest for each person/session. We ran another paired t-test at the group level to test pre vs post differences. SD shows t-stat variability across people in respective groups. A t-stat of 0 shows no BOLD change, a large positive t-stat shows increase BOLD change (increased connectivity, better outcome), and a large negative t-stat shows decrease BOLD change (decreased connectivity, worse outcome) pre vs post.

9-hole peg test (9-HPT) is a manual dexterity measure in which a participant must place 9 pegs in board with 9 holes, and remove all 9 pegs upon the insertion of all 9 pegs. This is completed with one peg at a time, and only one hand is used. For our study, only the right hand was used. The performance is estimated as the time required to complete the task (seconds). A lower time in seconds is indicative of a better score. For percent change in performance, a higher positive percent is indicative improved performance.

Motor cortical excitability is measured by electromyography using MEPs (motor evoked potentials) elicited by TMS (Transcranial magnetic stimulation) to a motor hotspot determined before collection of baseline (baseline occurs before intervention) MEP (motor evoked potential) collection. An increase in MEPs (motor evoked potentials) is indicative of increased cortical excitability. A positive increase in MEP (motor evoked potential) percent change is indicative of increased cortical excitability.

Resting-state connectivity of low frequency BOLD (blood oxygenation level dependent) fluctuations for a seed at the PPC (posterior parietal cortex). The original analysis was a time-series correlation (Pearson's R) of resting state fMRI data between two regions of interest. The Z-score a Fisher's r-to-z transform. 0 for the Z value means that the pearson's correlation was also 0, positive means positive correlation and negative means it was a negative correlation. Therefore, standard deviations above the mean represented greater connectivity between the regions of interest. There were no clinically relevant thresholds to consider.

Parietal-frontal cortical grasping network defined by BOLD change during precision force-tracking task. t-test statistics were acquired for BOLD activation (estimated with univariate GLMs within each individual) from scans pre and post (session 2 and 8/9) with free surfer software. We ran univariate GLMs for each session for each individual that gave regression coefficients (beta values) for each voxel. We calculated a t-stat for each of those beta-values (each person and session we have a t-stat for our contrast of interest at each voxel). We averaged these across region of interest for each person/session. We ran another paired t-test at the group level to test pre vs post differences. SD shows t-stat variability across people in respective groups. A t-stat of 0 shows no BOLD change, a large positive t-stat shows increase BOLD change (increased connectivity, better outcome), and a large negative t-stat shows decrease BOLD change (decreased connectivity, worse outcome) pre vs post.

Parietal-frontal cortical grasping network defined by BOLD change during precision force-tracking task. t-test statistics were acquired for BOLD activation (estimated with univariate GLMs within each individual) from scans pre and post (session 2 and 7) with free surfer software. We ran univariate GLMs for each session for each individual that gave regression coefficients (beta values) for each voxel. We calculated a t-stat for each of those beta-values (each person and session we have a t-stat for our contrast of interest at each voxel). We averaged these across region of interest for each person/session. We ran another paired t-test at the group level to test pre vs post differences. SD shows t-stat variability across people in respective groups. A t-stat of 0 shows no BOLD change, a large positive t-stat shows increase BOLD change (increased connectivity, better outcome), and a large negative t-stat shows decrease BOLD change (decreased connectivity, worse outcome) pre vs post.

Parietal-frontal cortical grasping network defined by BOLD change during precision force-tracking task. t-test statistics were acquired for BOLD activation (estimated with univariate GLMs within each individual) from scans pre and post (session 2 and 8/9) with free surfer software. We ran univariate GLMs for each session for each individual that gave regression coefficients (beta values) for each voxel. We calculated a t-stat for each of those beta-values (each person and session we have a t-stat for our contrast of interest at each voxel). We averaged these across region of interest for each person/session. We ran another paired t-test at the group level to test pre vs post differences. SD shows t-stat variability across people in respective groups. A t-stat of 0 shows no BOLD change, a large positive t-stat shows increase BOLD change (increased connectivity, better outcome), and a large negative t-stat shows decrease BOLD change (decreased connectivity, worse outcome) pre vs post.

The force tracking task measures one's ability to regulate their grip force. For this task, the participant must adjust their grip of an object to move the cursor in order to correspond with a constantly moving target. The outcome of this measure is the squared distance (error) from the cursor to the target in the precision force-tracking task, estimated as the root mean squared error (RMSE). A lower root mean squared error (RMSE) is indicative of better performance and better ability of a participant to regulate their grip force. A higher percent change in root mean squared error (RMSE) accuracy is indicative of better performance and better ability of a participant to regulate their grip force. It was assessed in session 2, 7, and 8/9, although only session 2 and 7 are reported here.

The force tracking task measures one's ability to regulate their grip force. For this task, the participant must adjust their grip of an object to move the cursor in order to correspond with a constantly moving target. The outcome of this measure is the squared distance (error) from the cursor to the target in the precision force-tracking task, estimated as the root mean squared error (RMSE). A lower root mean squared error (RMSE) is indicative of better performance and better ability of a participant to regulate their grip force. A higher percent change in root mean squared error (RMSE) accuracy is indicative of better performance and better ability of a participant to regulate their grip force. It was assessed in session 2, 7, and 8/9, although only session 2 and 8/9 are reported here.

The cRT (2-choice reaction time control task) is a measurement of visuomotor abilities that are non specific to the reach-to-grasp movement. The outcome for this measure is the mean reaction time for subjects responding in the cRT (2-choice reaction time control task), for correct responses. A lower mean reaction time in seconds is indicative of better visuomotor performance (non specific to the reach-to-grasp movement). A positive percent change in cRT (2-choice reaction time control task) is indicative of better visuomotor performance (non specific to the reach-to-grasp movement).

The cRT (2-choice reaction time control task) is a measurement of visuomotor abilities that are non specific to the reach-to-grasp movement. The outcome for this measure is the mean reaction time for subjects responding in the cRT (2-choice reaction time control task), for correct responses. A lower mean reaction time in seconds is indicative of better visuomotor performance (non specific to the reach-to-grasp movement). A positive percent change in cRT (2-choice reaction time control task) is indicative of better visuomotor performance (non specific to the reach-to-grasp movement).

Parietal-motor functional connectivity is measured by electromyography using MEPs (motor evoked potentials) elicited by dual-site TMS (Transcranial magnetic stimulation) to the motor hotspot and a parietal region determined at baseline (baseline occurs before intervention), while subjects perform an object-directed grasp/subjects are at rest. An increase in MEPs (motor evoked potentials) is indicative of increased cortical excitability. A positive increase in MEP (motor evoked potential) percent change, or normalized MEP (motor evoked potential), is indicative of increased cortical excitability. It was assessed in session 1, 3, 4, 5, 6, and 7, although only session 6 is reported here.

Parietal-motor functional connectivity is measured by electromyography using MEPs (motor evoked potentials) elicited by dual-site TMS (Transcranial magnetic stimulation) to the motor hotspot and a parietal region determined at baseline (baseline occurs before intervention), while subjects perform an object-directed grasp/subjects are at rest. An increase in MEPs (motor evoked potentials) is indicative of increased cortical excitability. A positive increase in MEP (motor evoked potential) percent change, or normalized MEP (motor evoked potential), is indicative of increased cortical excitability.