Decision Making, Impulsivity
Conditions
Keywords
transcranial Direct Current Stimulation (tDCS), Decision-making, Implusivity, Brain stimulation
Brief summary
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.
Detailed description
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.
Interventions
Non-invasive brain stimulation
BEHAVIORALCognitive training
Iowa Gambling Task will be used for cognitive training
OTHERSham transcranial Direct Current Stimulation (tDCS)
Non-invasive brain stimulation
Sponsors
University of Nottingham
Dr. Najat Khalifa
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
Participants will be randomly assigned to receive either combined anodal tDCS and cognitive training or combined sham tDCS and cognitive training. The participants will be blind to whether the tDCS is active or sham.
Intervention model description
Single blind Randomized Controlled Trial
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* Consenting volunteers aged between 18 and 40.
Exclusion criteria
* Individuals with epilepsy, other neurological conditions and history of significant head injury will be excluded. * Individuals with a history of substance misuse, major mental disorder and those receiving psychotropic medication will be also excluded.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Iowa Gambling Task (IGT) net scores | Change from baseline after 20 minutes of combined cognitive training and tDCS stimulation | IGT is a measure of decision making under conditions of uncertainty and risk. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Stop Signal Task (SST) reaction time | Change from baseline after 20 minutes of combined cognitive training and tDCS stimulation | SST is a measure of inhibitory control |
| Urgency, Perseveration, Premeditation, Sensation Seeking + Positive Urgency (UPPS+P) Impulsive Behavior Scale total scores | Baseline | 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. |
| Abbreviated Profile of Mood States (POMS) Total Mood Disturbance score | Baseline | 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. |
Countries
Canada
Contacts
Primary ContactNajat Khalifa, MD, FRCPC
Backup ContactTariq Hassan, FRCPSC
Outcome results
None listed