An interventional study of Anodal transcranial Direct Current Stimulation (tDCS) and Cognitive training in Impulsivity and Decision Making, sponsored by Dr. Najat Khalifa. Recruiting at 1 site in Canada. Open to participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-08-08.
Sponsored by Dr. Najat Khalifa · Not applicable, Interventional, and Treatment
This study aims to (i) assess the effects of combined tDCS and cognitive training on decision-making on a trained task (Iowa Gambling Task; IGT); and (ii) test generalization to a closely related cognitive domain, namely motor impulsivity. It is hypothesized that combined anodal tDCS and cognitive training will result in more advantageous decisions and better impulse control than combined sham tDCS and cognitive training.
Impaired decision-making under conditions of uncertainty and risk has been implicated in maladaptive personality development and violent behaviour. There is a dearth of studies that examined the effects of combined tDCS and cognitive training on decision-making under conditions of uncertainty and risk. It is also unclear if these effects are generalizable to tasks in other domains such as response inhibition (motor impulsivity).
To examine these issues further, a single blind parallel arms randomized controlled trial will be conducted, involving a sample of healthy volunteers aged between 18 and 40. This will entail applying either active or sham tDCS over the anterior frontal cortex (including the vm-PFC) while participants undertake decision-making training using the Iowa Gambling Task. Decision-making will be assessed using the IGT, which is a computerized gambling task used to assess decision-making under conditions of uncertainty and risk. IGT is sensitive to damage to the ventromedial prefrontal cortex (vmPFC), which is considered to play a key role in decision-making. Motor impulsivity will be measured using the Stop Signal Task (SST). The UPPS+P Impulsive Behaviour Scale will be used to index trait impulsivity. The Profile of Mood States will be used to measure state emotion before and after tDCS.
158 studies on the registry are indexed under Impulsive Behavior; 31 are open to participants now.
This study's planned enrollment of 60 is above the median of 50 across 128 interventional studies indexed under Impulsive Behavior.
Browse Impulsive Behavior studies →Dr. Najat Khalifa is the lead sponsor of 2 studies on the registry; 2 are open to participants now.
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Exclusion Criteria:
Combined anodal tDCS and cognitive training. Anodal tDCS will be delivered while the participant is completing the cognitive training task (Iowa Gambling Task). Anodal tDCS will use a constant current of 2mA, delivered via gradual increase and decrease over 10 seconds at the onset and offset of stimulation (current ramps), respectively. The duration of each tDCS session will be 20 minutes.
Other: Anodal transcranial Direct Current Stimulation (tDCS) · Behavioral: Cognitive training
Combined sham tDCS and cognitive training. Sham tDCS will be delivered while the participant is completing the cognitive training task (Iowa Gambling Task). For sham tDCS, the current will be delivered only in the first 10 seconds, after which the stimulation will cease but with the electrodes still in place throughout the session. The duration of each tDCS session will be 20 minutes.
Behavioral: Cognitive training · Other: Sham transcranial Direct Current Stimulation (tDCS)
Non-invasive brain stimulation
Iowa Gambling Task will be used for cognitive training
Non-invasive brain stimulation
Iowa Gambling Task (IGT) net scores
IGT is a measure of decision making under conditions of uncertainty and risk.
Time frame: Change from baseline after 20 minutes of combined cognitive training and tDCS stimulation
Stop Signal Task (SST) reaction time
SST is a measure of inhibitory control
Time frame: Change from baseline after 20 minutes of combined cognitive training and tDCS stimulation
Urgency, Perseveration, Premeditation, Sensation Seeking + Positive Urgency (UPPS+P) Impulsive Behavior Scale total scores
UPPS+P is a 59 item self-report measure of trait impulsivity. Each item is rated on a scale of 1-4 (1= totally disagree, 4=totally agree) yielding a total score out of 216 (range=59 - 216) Higher scores denote higher impulsivity.
Time frame: Baseline
Abbreviated Profile of Mood States (POMS) Total Mood Disturbance score
Abbreviated POMS is a 40-item measure of current mood states. Each item is rated on a scale of 0-4 (0=Not at all, 4=Extremely). The total Mood Disturbance score is calculated by summing the totals for the negative subscales (tension, depression, anger, fatigue, confusion) and then subtracting the totals for the positive subscales (vigour, esteem related affect) and then adding a constant 100. Higher scores denote greater mood disturbance.
Time frame: Baseline
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No — No participant data will be shared with researchers other than the study investigators.
Started Sep 2022 (actual). Primary completion is estimated for Dec 2026, 51 months after the start.
Of 55 non-industry interventional studies with no phase under Impulsive Behavior, half reached primary completion within 26 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 34. This study's planned 51 months is above that.
Counting every sponsor, half of 55 studies reached it within 26 months; a quarter within 13 and three quarters within 34.
How these figures are worked out, and which studies are left out of them.
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Dr. Najat Khalifa