Transcranial Direct Current Stimulation and Antisocial Behavior

Not Applicable

Active, not recruiting

• Conditions: Aggression
• Interventions: Device: Sham transcranial direct current stimulation; Device: Transcranial direct current stimulation

• Registration Number: NCT04204759
• Lead Sponsor: Nanyang Technological University

Brief Summary

The main objective of this study is to investigate the causal relationship between prefrontal cortex activity and antisocial behavior, as well as risk factors for antisocial behavior. Specifically, this study tests the hypothesis that upregulating activity in the prefrontal cortex through a non-invasive form of brain stimulation, transcranial direct current stimulation (tDCS) will reduce antisocial and aggressive behavior. The effects of 3 days of anodal stimulation over the prefrontal cortex are assessed.

Detailed Description

Not available

Study Timeline

• Study Start: 2019-11-03
• Study First Submitted: 2019-12-17
• Study First Submitted QC: 2019-12-17
• Study First Posted: 2019-12-19
• Primary Completion: 2022-05-01
• Status Verified: 2022-10
• Last Update Submitted: 2022-10-17
• Last Update Posted: 2022-10-18
• Study Completion: 2023-12-31

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 101

Inclusion Criteria

• Above 18 (with parental consent) or above 21 (without parental consent)
• Able to understand the nature of the study and give informed consent

Exclusion Criteria

• History of or active neurologic, cardiovascular, or psychiatric disease including anxiety disorders (e.g., PTSD, panic attacks, obsessive-compulsive disorder) and mood disorders (e.g., depression)
• Currently consuming anti-convulsant, anti-psychotic, or sedative/hypnotic medications
• Currently consuming anti-depressants
• History of seizures
• Metallic implants on scalp
• Participated in any other non-invasive brain stimulation study in the same day
• Ever had an adverse reaction to tDCS

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Sham stimulation	Sham transcranial direct current stimulation	The sham tDCS condition will involve the same placement of the electrodes, current intensity, and ramp-up/down time as the active tDCS condition, but stimulation will only last for 30 seconds.
Anodal stimulation	Transcranial direct current stimulation	Participants in the active stimulation group will undergo anodal transcranial direct current stimulation (tDCS). tDCS will be delivered by a battery-driven, constant-current stimulator connected to two saline-soaked surface sponge electrodes. An anodal electrode (25cm2) will be placed over the ventromedial prefrontal cortex and one cathodal electrode (35cm2) will be placed over the occipital cortex. Scalp electrodes will be positioned according to the 10-20 EEG international system. A current of 2mA will be applied for 20 minutes and the current will be ramped up and down over 30 seconds at the beginning and end of the stimulation period.

Primary Outcome Measures

Name	Time	Method
Delay discounting rates after stimulation	Within 1 hour after the third consecutive active tDCS or sham session	Participants' responses to 5 questions indicating if they would prefer a smaller reward today or a larger reward in the specified number of days will be assessed. The delay discount rates (k) of monetary rewards will be calculated based on the responses to the 5 trials.
Points in the Point Subtraction Aggression Paradigm after stimulation	Within 1 hour after the third consecutive active tDCS or sham session	The number of points earned on the lab task will be assessed.
Helping behavior after stimulation	Within 1 hour after the third consecutive active tDCS or sham session	This will be assessed based on the number of easy and hard puzzles participants choose to assign to another participant in the study.
Antisocial behavior after stimulation	Within 1 hour after the third consecutive active tDCS or sham session	This will be assessed based on the participants' accurate reporting of the number of problems correctly solved in a task.
Moral judgment ratings after stimulation	Within 1 hour after the third consecutive active tDCS or sham session	This will be assessed using 5 hypothetical scenarios in which someone commits a criminal or antisocial act. Participants will rate the moral wrongfulness of the act in the scenario on a scale from 0 (not at all) to 10 (very). A higher score reflects a greater perception of moral wrongfulness regarding the antisocial act.
Antisocial behavior inclinations after stimulation	Within 1 hour after the third consecutive active tDCS or sham session	This will be assessed using 5 hypothetical scenarios in which someone commits a criminal or antisocial act. Participants will respond to the likelihood that they would commit the act in the scenario according to a 10-point Likert scale. Responses are measured on a scale ranging from zero (no chance at all) to 10 (100% chance). A higher value reflects a greater intention to engage in the antisocial act.

Secondary Outcome Measures

Name	Time	Method
Number of participants with adverse events	Within 1 hour after each of the 20-minute active tDCS or sham sessions	The number of participants reporting the experience of sensations resulting from tDCS will be recorded.

Trial Locations

Locations (1)

Nanyang Technological University; 🇸🇬 Singapore, Singapore