title: The truth about lying: inhibition of the anterior prefrontal cortex improves deceptive behavior.
abstract: Recent neuroimaging studies have indicated a predominant role of the anterior prefrontal cortex (aPFC) in deception and moral cognition, yet the functional contribution of the aPFC to deceptive behavior remains unknown. We hypothesized that modulating the excitability of the aPFC by transcranial direct current stimulation (tDCS) could reveal its functional contribution in generating deceitful responses. Forty-four healthy volunteers participated in a thief role-play in which they were supposed to steal money and then to attend an interrogation with the Guilty Knowledge Test. During the interrogation, participants received cathodal, anodal, or sham tDCS. Remarkably, inhibition of the aPFC by cathodal tDCS did not lead to an impairment of deceptive behavior but rather to a significant improvement. This effect manifested in faster reaction times in telling lies, but not in telling the truth, a decrease in sympathetic skin-conductance response and feelings of guilt while deceiving the interrogator and a significantly higher lying quotient reflecting skillful lying. Increasing the excitability of the aPFC by anodal tDCS did not affect deceptive behavior, confirming the specificity of the stimulation polarity. These findings give causal support to recent correlative data obtained by functional magnetic resonance imaging studies indicating a pivotal role of the aPFC in deception.
authors.affiliation: Institute of Medical Psychology and Behavioral Neurobiology, University of Tuebingen, Gartenstrasse 29, Tuebingen, Germany. ahmed.karim@uni-tuebingen.de
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Karim
authors.forename: Markus
authors.initials: M
authors.lastname: Schneider
authors.forename: Martin
authors.initials: M
authors.lastname: Lotze
authors.forename: Ralf
authors.initials: R
authors.lastname: Veit
authors.forename: Paul
authors.initials: P
authors.lastname: Sauseng
authors.forename: Christoph
authors.initials: C
authors.lastname: Braun
authors.forename: Niels
authors.initials: N
authors.lastname: Birbaumer
mesh_terms: D000328:Adult; D003242:Conscience; D008192:Deception; D004558:Electric Stimulation; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology*; D006167:Guilt; D006801:Humans; D008014:Lie Detection; D008297:Male; D009433:Neural Inhibition / Q000502:physiology*; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000502:physiology*; D012381:Role Playing; D055815:Young Adult