Clinical Trial: The Effect of Prefrontal Cortex Stimulation on Antisocial and Aggressive Behavior

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: The Effect of Transcranial Direct Current Stimulation of the Prefrontal Cortex on Antisocial and Aggressive Behavior

Brief Summary: This study investigates the effect of upregulating prefrontal cortex activity on antisocial and aggressive behavior and risk factors for such behavior. In the double-blind, randomized controlled trial, participants will undergo anodal transcranial direct current stimulation bilaterally to the dorsolateral prefrontal cortex or a sham stimulation. During and after stimulation, they will complete survey and laboratory measures assessing antisocial and aggressive behavior and risk factors for antisocial and aggressive behavior. Heart rate and skin conductance will also be measured.

Detailed Summary:
Sponsor: University of Pennsylvania

Current Primary Outcome:

  • Change in antisocial behavior inclinations at 40 minutes [ Time Frame: Baseline (an average of 15 minutes before receiving tDCS or sham) and within 40 minutes following stimulation or sham ]
    This will be assessed using 10 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.
  • Change in antisocial behavior inclinations at 24 hours [ Time Frame: Baseline (an average of 15 minutes before receiving tDCS or sham) and on average, 24 hours following stimulation or sham ]
    This will be assessed using 10 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.
  • Number of pins inserted into a virtual voodoo doll at 40 minutes [ Time Frame: Within 40 minutes after the 20-minute tDCS or sham session ends ]
    The number of pins (between 0 and 51) that participants decide to insert into a picture of a voodoo doll on a computer that represents either a romantic partner or close friend will be recorded within 40 minutes after receiving tDCS or sham stimulation.
  • Number of pins inserted into a virtual voodoo doll at 24 hours [ Time Frame: On average, 24 hours after the tDCS or sham session ]
    The number of pins (between 0 and 51) that participants decide to insert into a picture of a voodoo doll on a computer that represents either a romantic partner

    Original Primary Outcome: Same as current

    Current Secondary Outcome:

    • Mean reaction time to visual stimuli [ Time Frame: Between 0 and 10 minutes of receiving tDCS or sham stimulation ]
      Attention performance will be assessed by subjects' response times to target stimuli shown at random intervals for 10 minutes.
    • Number of attentional lapses in responding to visual stimuli [ Time Frame: Between 0 and 10 minutes of receiving tDCS or sham stimulation ]
      Attention performance will also be assessed by the number of attentional lapses, considered as the number of trials in the 10-minute task in which subjects respond 500 ms or later after the visual stimulus has been shown.
    • Number of cards picked from the two "risky decks" in the Iowa Gambling Task [ Time Frame: Between 10 and 20 minutes after the start of receving tDCS or sham stimulation ]
      The number of cards picked from the two "risky decks", where money is lost in the long-run, rather than the two "safe decks" in the Iowa Gambling Task will be recorded. Specifically, the number of cards picked from the two ''risky decks'' in the second half of the task will be summed.
    • Delayed reward discounting rate [ Time Frame: Within 40 minutes after the 20-minute tDCS or sham session ends ]
      Subjects' estimated delayed reward discounting rate is calculated as the geometric mean of the discounting rate at indifference between the 2 questions out of 27 that reflect when the subject changes between choosing a delayed reward rather than an immediate reward.
    • Number of balloon pumps in the Balloon Analogue Risk Task [ Time Frame: Within 40 minutes 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 30 trials, will be measured.
    • Choice regarding the length of a prison sentence in a hypothetical juror scenario [ Time Frame: Within 40 minutes after the 20-minute tDCS or sham session ends ]
      The participant's choice out of 7 options in a multiple-choice format regarding the length of a prison sentence, if any, that an offender should serve following a 2-year, nearly 100% effective rehabilitation treatment in a fictional vignette, will be recorded to assess retributive punishment.
    • Sum of self-reported ratings on free will beliefs in Paulhus and Carey's (2011) Free Will and Determinism Plus Scale [ Time Frame: Within 40 minutes after the 20-minute tDCS or sham session ends ]
      The self-reported ratings on seven items, based on a five-point scale in Paulhus and Carey's (2011) Free Will and Determinism Plus questionnaire, will be summed to obtain a composite score reflecting free will beliefs.
    • The occurrence of a moral or immoral event in the 3 hours prior to the testing session [ Time Frame: Within 40 minutes after the 20-minute tDCS or sham session ends ]
      Participants indicate whether they have experienced a moral or immoral event in the 3 hours prior to the testing session as a qualitative assessment of their perception of moral experiences in daily life.
    • Decisions to keep or transfer endowments to a fictional player [ Time Frame: Within 40 minutes after the 20-minute tDCS or sham session ends ]
      Participants' decisions to keep or transfer 10 monetary units to another player in a one-shot prisoner's dilemma game will be assessed as a measure of level of cooperation.
    • The amount of money participants would offer and accept from a fictional player in an ultimatum game [ Time Frame: Within 40 minutes after the 20-minute tDCS or sham session ends ]
      As another measure of cooperative behavior, participants' decisions about how much money they would offer and accept from another player will be recorded in a one-shot ultimatum game.
    • Heart rate levels in response to emotionally provocative stimuli [ Time Frame: Between 10 and 20 minutes after the start of receving tDCS or sham stimulation ]
      Heart rate levels in beats per minute will be recorded.
    • Skin conductance levels in response to emotionally provocative stimuli [ Time Frame: Between 10 and 20 minutes after the start of receving tDCS or sham stimulation ]
      Skin conductance levels, in seimens, will be recorded.
    • Change in ratings of positive and negative affect according to the Positive and Negative Affect Schedule (PANAS) at 40 minutes [ Time Frame: Baseline (an average of 15 minutes before receiving tDCS or sham) and within 40 minutes following stimulation or sham ]
      Participants' responses to 41 adjectives on a 5-point Likert scale will be assessed. Levels of positive and negative affect will be calculated based on the sum of t

      Original Secondary Outcome: Same as current

      Information By: University of Pennsylvania

      Dates:
      Date Received: March 26, 2015
      Date Started: March 2015
      Date Completion: April 2018
      Last Updated: April 25, 2017
      Last Verified: April 2017