Activity of the Left Inferior Frontal Gyrus and the Error Detection Mechanism during Deception in Conditions of Different Monetary Benefit

We report here studies addressing the characteristics of activity in the brain areas supporting the control of actions and subject to modulating influences from the error detection mechanism in conditions of different potential monetary benefits of manipulative truthful and deceitful actions. Implementation of potentially less profitable deceitful actions was found to be associated with a relatively higher level of functional activity in the structure receiving information from the brain structures associated with error detection, i.e., the left inferior frontal gyrus. This effect was found in experimental conditions with less strongly reinforced deceitful actions in comparison with both relatively more strongly rewarded lies and with manipulative truthful actions, regardless of the nature of their encouragement. Moreover, an increase in the benefit of deceitful actions was accompanied by the disappearance of the statistically significant difference in activity in the ventrolateral prefrontal cortex seen in the comparison between equally low-benefit truthful and deceitful actions. These results point to a possible mechanism for the influence of expected monetary benefit on adoption of the manipulative decision to lie, whereby prefrontal structures supporting the control of behavior have relatively lower susceptibility to involvement of the error detector in supporting deceitful actions.