Aggression, Antisocial Behavior, Risk-Taking
Conditions
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.
Interventions
DEVICETranscranial direct current stimulation
Transcranial direct current stimulation will be administered for 20 minutes using a CE approved stimulator (NeuroConn, Ilmenau, Germany).
DEVICESham transcranial direct current stimulation
The same device will be used as in the active stimulation group, but stimulation will be terminated after 30 seconds.
Sponsors
RWTH Aachen University
Olivia Choy
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
MALE
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Between 18 and 50 years of age * Able to understand the nature of the study and give informed consent * Individuals in the violent offender group must have a record of repeated violent criminal offending (at least 2 felonies). * Individuals in the violent offender group must have been convicted solely due to crimes involving violence motivated by impulsive aggression.
Exclusion criteria
* Presence of any contraindications for functional magnetic resonance imaging (fMRI) * History of significant medical illness * History of any neurological condition * Diagnosis of schizophrenia * History of epilepsy * Head injury * Mental retardation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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. |
| 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. |
| 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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. |
| 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. |
Countries
Germany
Outcome results
None listed