Combined Anodal Transcranial Direct Current Stimulation (tDCS) and Cognitive Training and Decision-making

Not Applicable

Recruiting

• Conditions: Impulsivity; Decision Making

• Registration Number: NCT03886025
• Lead Sponsor: Dr. Najat Khalifa

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.

Study Timeline

• Study First Submitted: 2019-03-15
• Study First Submitted QC: 2019-03-20
• Study First Posted: 2019-03-22
• Study Start: 2022-09-15
• Status Verified: 2024-04
• Last Update Submitted: 2024-04-01
• Last Update Posted: 2024-04-02
• Primary Completion: 2025-03-30
• Study Completion: 2025-04-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 60

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
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 Outcome Measures

Name	Time	Method
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
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.
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.

Trial Locations

Locations (1)

Queen's University; 🇨🇦 Kingston, Ontario, Canada