MODULATION OF DECEPTION WITH PREFRONTAL TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS)

Recent fMRI studies have indicated a predominant role of the frontopolar cortex (FPC; BA 9/10) in deception and moral cognition, yet the functional contribution of the FPC remains elusive. Here we demonstrate the effect of prefrontal tDCS on deception. Three experiments were conducted to test the specificity of the transcranial stimulation effect. In the first experiment subjects participated in a mock crime and a subsequent interrogation with the Guilty Knowledge Test. Remarkably, inhibition of the FPC 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 SCR and feelings of guilt while deceiving the interrogator and a significantly higher lying quotient reflecting skilful lying. In the second experiment reversing the stimulation polarity had no effect on deceptive behavior, confirming the specificity of the applied polarity. In the third experiment the Stroop-test was used as a control task. Our results demonstrate that although the incongruent condition is cognitively more demanding than the congruent one, tDCS of the FPC had no effect on performance, suggesting a specific effect on deceptive behavior and not on cognitively demanding tasks in general. Our findings support the notion that a dysfunction of the FPC may underlie certain psychopathological disorders (i.e., psychopathy) that are characterized by the absence of sympathic arousal while performing an antisocial act such as deceiving in a criminal interrogation