Transcranial Direct Current Stimulation in Offenders
Study Details
Study Description
Brief Summary
This study investigates the effect of upregulating prefrontal cortex activity on risk-taking, and antisocial and aggressive behavior in violent offenders. In the double-blind, randomized controlled trial, using a within-subject crossover design, each participant will undergo anodal transcranial direct current stimulation of the right dorsolateral prefrontal cortex and sham stimulation. After each stimulation session, neural activity and behavioral responses to tasks assessing risk-taking and aggressive behavior will be recorded. The effect of tDCS on violent offenders will also be assessed in comparison to age and gender-matched healthy controls.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Anodal 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 right dorsolateral prefrontal cortex and one cathodal electrode (100cm2) will be placed over the left supraorbital area at least 5cm from the anode. 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 20 seconds at the beginning and end of the stimulation period. |
Device: Transcranial direct current stimulation
Transcranial direct current stimulation will be administered for 20 minutes using a CE approved stimulator (NeuroConn, Ilmenau, Germany).
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| Sham Comparator: Sham 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. |
Device: Sham transcranial direct current stimulation
The same device will be used as in the active stimulation group, but stimulation will be terminated after 30 seconds.
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Outcome Measures
Primary Outcome Measures
- Number of balloon pumps in the Balloon Analogue Risk Task after stimulation [Within 1 hour after the 20-minute tDCS or sham session ends]
The number of balloon pumps, measured by the number of times subjects press a button to pump up a computerized balloon over 60 trials, will be assessed.
- Neural activity during Balloon Analogue Risk Task after stimulation [Within 1 hour after the 20-minute tDCS or sham session ends]
Functional brain activity and connectivity will be assessed using functional magnetic resonance imaging.
- Aggressive behavior after stimulation [Within 1 hour after the 20-minute tDCS or sham session ends]
This will be assessed according to performance on the violent video game, Carmageddon: TDR 2000 (Klasen et al., 2013; Torus Games, Bayswater, Australia, 2000) in comparison to a modified non-violent version of the game.
- Neural activity during aggression task after stimulation [Within 1 hour after the 20-minute tDCS or sham session ends]
Functional brain activity and connectivity during participation in the video game will be assessed using functional magnetic resonance imaging.
- Antisocial behavior inclinations after stimulation [Within 1 hour after the 20-minute tDCS or sham session ends]
This will be assessed using 8 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.
Secondary Outcome Measures
- Number of participants with adverse events [Within 1 hour after the 20-minute tDCS or sham session ends]
The number of participants reporting the experience of sensations resulting from tDCS will be recorded.
- Ratings of guilt or shame regarding antisocial acts after stimulation [Within 1 hour after the 20-minute tDCS or sham session ends]
This will be assessed using 8 hypothetical scenarios in which someone commits a criminal or antisocial act. Participants will respond to the likelihood that they would feel a sense of guilt or shame according to a 10-point Likert scale.
- Ratings of moral wrongfulness regarding antisocial acts after stimulation [Within 1 hour after the 20-minute tDCS or sham session ends]
This will be assessed using 8 hypothetical scenarios in which someone commits a criminal or antisocial act. Participants will rate the moral wrongfulness of the acts according to a 10-point Likert scale.
Eligibility Criteria
Criteria
Inclusion Criteria:
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Between 18 and 50 years of age
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Able to understand the nature of the study and give informed consent
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Individuals in the violent offender group must have a record of repeated violent criminal offending (at least 2 felonies).
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Individuals in the violent offender group must have been convicted solely due to crimes involving violence motivated by impulsive aggression.
Exclusion Criteria:
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Presence of any contraindications for functional magnetic resonance imaging (fMRI)
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History of significant medical illness
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History of any neurological condition
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Diagnosis of schizophrenia
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History of epilepsy
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Head injury
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Mental retardation
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Uniklinik RWTH Aachen | Aachen | Germany | 52074 |
Sponsors and Collaborators
- Olivia Choy
- RWTH Aachen University
Investigators
- Principal Investigator: Ute Habel, PhD, RWTH Aachen University
Study Documents (Full-Text)
None provided.More Information
Publications
- EK 341/16