Deceptive And Truthful Response And The Practice Effects To Personal Information: An ERP Study

Lying is ubiquitous in social interaction. From the perspective of evolution, the emergence of deception enables human beings to smooth social interaction. On the other hand, from the view of information processing, lying recruits response inhibition, response selection, performance monitoring and mentalizing others, all of which constitute cognitive control or executive function. Meanwhile, lying, as a top-down modulated behavior, is not a homogenous behavior. Lying can be divided into different subtypes along different dimensions. Here we divided the lying into two categories: denying and fabricating. Exploring the neural substrates underlying deception and sub-categories of deception would improve our understanding within the realm of executive function. Additionally, deception could be categorized as spontaneous lie and well-practiced lie. From one hand, the practice effects on lies could theoretically boost our understanding of the plasticity of neural mechanism underlying executive control. Likewise, understanding the behavior performance and neural activity of well-practiced lie will shed light on lie detection studies, which mainly focus on the spontaneous lie. The current research aims to explore the questions mentioned above.This research included three experiments, employing the differentiation of deception paradigm (DDP). Participants' personal information was used as experimental materials. Experiment 1 manipulated stimulus type (personal information and non-personal information) and response mode (deceptively and truthfully) orthogonally. This constitutes truthful and deceptive response and two types of deception: denying one's identity and fabricating one's identity. Event-related potentials and behavioral performance were recorded simultaneously. Experiment 2 used same materials but without recording event-related potentials. It required participants to practice lies under effective feedback three times. In experiment 3, the participants performed the practiced deceptive task using same stimuli while recording event-related potentials. The current research has achieved such conclusions:(1) Deceptive response is characterized by prolonged reaction time, larger variance and lower correct rate.(2) Compared with truth, deception has elicited significantly larger N1 and N2. N1 is indicative of enhanced attention to deceptive stimuli whereas N2 reflects conflict monitoring during lying.(3) Participants' self-referring knowledge has elicited significantly larger P3 than non-self-referring knowledge, which indicates the classification and evaluation of these two kinds of stimuli.(4) Different types of lies have different behavioral performance and neural activity. Compared to fabricating, denying involves more cognitive conflict.(5) Practice has exerted significantly influence on deceptive response in respect to reaction time, variance and correct rate. The well-practiced lies are significantly faster than pre-practice lie and even truthful response, so does the variance. However, well-practiced lies are still associated with more errors than truth, though significantly lower than pre-practiced lies.(6) Practice influences subtypes of lies differently: the fabricating lies are more easily to practice.(7) There is no significant difference between well-practiced lies and truth lies in respect of ERP activity. This shows that practice has changed the brain activity, as shown by the reduced N1 and N2. Moreover, for fabricating lies, the well-practiced lies are significantly smaller than pre-practiced lies regarding N2.(8) After practice, the P3 can not differentiate self with non-self information.The innovative part of the research: the current research employed thedifferentiation of deception paradigm, which excludes stimuli probability and stimuli meaning, to investigate the neural substrates of deception. The N2 effect here lends support to the notion that lying involves response conflict and monitoring. Moreover, the current study, for the first time, has found that after a certain amount of practice with effective feedback, the deceptive performance could change substantially, as evidenced by abated reaction time, lessened response variance and improved correct rate. The well-practiced lies could even be faster than truth. Another novel finding here is that the N2 educed by well-practiced lies was not different from truth, therefore support the notion that "a lie repeated for one thousand times would become truth". Finally, via the correlation analysis of N2 and behavioral performance, the results favor the conflict-monitoring hypothesis of N2 and anterior cingulate cortex.