tDCS for Impulsivity and Compulsivity in Obesity

Differences in change in NIH Examiner Dot Counting Task scores (i.e., score at final visit minus baseline score) between active tDCS-cognitive training and sham-cognitive training groups. The change in score is equal to the score taken at the final follow-up visit minus the score taken at baseline. NIH Dot Counting absolute value range: numerical value -27 to +27. Higher values represent a better outcome. The Dot Count Task Score is the total sum of points awarded for dots a participant counts on the screen. The total score is a sum of scores for 27 individual trials.

Time frame: Change between baseline and 4 months post-stimulation (i.e., timepoint 8/final visit)

Population: Due to the Coronavirus (COVID-19) pandemic preventing in-person data collection of task data, the N for this measure is lower than the baseline N.

Differences in change in Flanker Task reaction time (score at final follow-up visit minus score at baseline) between active tDCS-cognitive training and sham-cognitive training groups. NIH Flanker absolute value range: 0 to 5 seconds. Higher values represent a better outcome. In the Flanker Task, a participant is instructed to press a key in response to viewing a stimulus presented on-screen. The Reaction Time, or the amount of time in seconds between presentation of the stimulus and the response, is measured.

Time frame: Change between baseline and 4 months post-stimulation (timepoint 8/final visit)

Population: Due to the Coronavirus (COVID-19) pandemic preventing in-person data collection of task data, the N for this measure is lower than the baseline N.

Difference in change in Set Shifting Task scores (score at final visit minus baseline score) between active tDCS-cognitive training and sham- Higher values represent a better outcome. Set Shifting Scale absolute value range: Minimum -10, Maximum 10. The Set Shifting Task Score is a combination of two subscores for reaction time and accuracy on the task.

Time frame: Change between baseline and 4 months post-stimulation (timepoint 8, final visit)

Population: Due to the Coronavirus (COVID-19) pandemic preventing in-person data collection of task data, the N for this measure is lower than the baseline N.

Differences in change in NIH Examiner Unstructured Planning Task scores (i.e., score at final visit minus baseline score) between active tDCS-cognitive training and sham-cognitive training groups. The change in score is equal to the score taken at the final follow-up visit minus the score taken at baseline. Higher values represent a better outcome. The Unstructured Task Score is a numeric summary score that is equal to the total sum of points awarded for completed puzzle items. The total absolute score is a sum of scores for 3 individual trials, Absolute score range :-1469 to +1469.

Time frame: Change between baseline and 4 months post-stimulation (i.e., timepoint 8, final visit)

Population: Due to the Coronavirus (COVID-19) pandemic preventing in-person data collection of task data, the N for this measure is lower than the baseline N.

Difference in change in weight (pounds) between active tDCS-cognitive training and sham-cognitive training groups (i.e., end of study weight minus baseline weight). A more negative score indicates a better outcome.

Time frame: Change between baseline and 4 months post-intervention (i.e., timepoint 8/final visit)

Population: Due to the Coronavirus (COVID-19) pandemic preventing in-person data collection of task data, the N for this measure is lower than the baseline N. One additional subject was excluded from the weight analysis due to participation in a commercial weight-loss program during the study.

Effect of history of a traumatic brain injury (TBI) on impulsive/compulsive eating behavior. A status of either TBI+ (positive for history of TBI) or TBI- (negative for history of TBI) was determined at the baseline visit with the Minnesota Blast Exposure Screening Tool. Impulsive/compulsive eating behavior was defined as the score on the Binge Eating Scale (BES) taken at the baseline visit. Scale range = 0-48. Lower scores indicate less impulsive/compulsive eating behavior (i.e., a better outcome). Calculation details: Average BES scores taken at baseline for TBI-positive participants and TBI-negative participants.

Time frame: Baseline visit

Population: Analysis was pre-specified at baseline to be reported by TBI status. Eight baseline participants did not complete the Minnesota Blast Exposure Screening Tool and were not included in this secondary analysis.

Effect of history of a traumatic brain injury (TBI) on impulsive behavior. A status of either TBI+ (positive for history of TBI) or TBI- (negative for history of TBI) was determined at baseline with the Minnesota Blast Exposure Screening Tool. Impulsive behavior was defined as the NIH Set Shifting score measured at baseline. Score range: 0 - 10. Higher scores indicate less impulsive behavior (i.e. a better outcome). Calculation details: Set Shifting scores for TBI-positive participants and TBI-negative participants.

Time frame: Baseline visit

Population: Eight baseline participants did not complete the Minnesota Blast Exposure Screening Tool and were not included in this post-hoc analysis.~Analysis was pre-specified at baseline to be reported by TBI status.

Effect of history of a traumatic brain injury (TBI) on impulsive behavior. A status of either TBI+ (positive for history of TBI) or TBI- (negative for history of TBI) was determined at baseline with the Minnesota Blast Exposure Screening Tool. Impulsive behavior was defined as the score on the Flanker task measured at the baseline visit. The Flanker score is equal to the average reaction time, in seconds, to respond to trials. Minimum = 0, maximum = 2. A higher score indicates less-impulsive behavior (i.e., a better outcome). Calculation details: Flanker scores for TBI-positive participants and TBI-negative participants.

Time frame: Baseline visit

Population: Analysis was pre-specified at baseline to be reported by TBI status. Eight baseline participants did not complete the Minnesota Blast Exposure Screening Tool and were not included in this post-hoc analysis.