The Neural Basis Of Spontaneous Deception In Strategic Interactions

Deception is a universal phenomenon in human society.Cognitive psychology defines deception as a kind of behavior that intentionally misleads others.According to this definition,except for directly telling false statement,a deceiver could also intentionally tell a truthful statement but mislead the recipient to believe its opposite.Most of the existing studies asked subjects to deceptive or respond honestly,these studies mainly focused on the first-order deception in which the deceiver made a false statement to deceive an unsuspecting opponent intentionally.In reality,second-order deception is very common in real life.Second-order deception refers to the situation whereby the deceivers are fully aware that the recipient is suspecting but still carry out intentional deceptive acts.Besides,deception is a complex social cognitive activity,which are involved in three stages: decision-making(the preparation for deception),the execution of deception,and outcome feedback.At present,most studies emphasize the processing of response execution in deception,especially the inhibition of truth response.Critically,during interpersonal deception,a deceiver may not only decide whether or when to tell a false or a truthful statement,but he also need to evaluate whether the deception has succeeded or not.However,the temporal characteristics of the deception's decision-making and outcome evaluation during the interpersonal deception game are still open questions.In order to further explore the dynamic neural pattern of the spontaneous deception in interactive situation,the present study employed fNIRS technology,combinating with a delayed-response experimental paradigm.Participants made a decision to lie or be truthful in each trial,and held their response until a delayed imperative signal was presented.Participants' brain activity was recorded while theyplayed the role of deceiver in the interpersonal deception game.During the game,participants deceived their opponents by using both true and false statements.In the control session,participants did not need to consider the confederate's suspicion,and they just told the truth(answering correctly)or made the false statement(answering incorrectly)all the time.This dissertation is divided into two parts.In the first part,the activation likelihood estimate(ALE)method of meta-analysis was used to quantitatively identify the brain regions that are consistently more active for deception(study 1).Further,we analyzed the similarities and differences of active brain regions between spontaneous deception and instructed deception(study 2).The meta-analysis found that deception activated the prefrontal cortex and temporospatial junction,suggesting that the dorsolateral prefrontal cortex and temporo-parietal junction(TPJ)were the core areas of deception,providing the basis for subsequent fNIRS studies to determine the regions of interest(ROI).In the second part,fNIRS technology was used to reveal the neural mechanism of deception behavior in interactive scenarios where both truthful and false statements were used to deceive others.This part further investigated the different neural patterns underlying spontaneous and instructed deception decisions.This part contains four experiments:The main purpose of experiment 1 was to verify the feasibility that fNIRS technology separates the stages of deception and lays a foundation for follow-up research.The delayed response paradigm was used to divide the deceptive response into two stages: the preparation stage and the execution stage.It was found that during the preparation stage,the honest response(correct response)showed activation in the dorsolateral prefrontal lobe,and the deceptive response(false response)showed deactivation.However,in the execution stage,the two kinds of responses did not show any significant difference in the brain activation area.It suggested that the deception effect is mainly manifested in the preparation stage for the deception rather than the execution stage of deception.It also revealed that fNIRS technology can separate the stages of deception.Experiment 2 compared the brain activation of telling truth to deception and answering correctly,aimed at revealing the neural mechanism of telling the truth to deceive in the interactive situation.It was found that truth with deception intention(telling truth to deception)showed deactivation in the dorsolateral prefrontal cortex,frontal pole and temporo-parietal junction(TPJ)during all the stage.This showed that truth-telling deception needs more psychological theory resources to make decisions.trying to deceive the interaction partner by telling the truth requires greater processing demands than answering correctly.Experiment 3 compared the difference in neural mechanisms between deception(deliberate falsehood/telling false statement)and deliberate falsehood unintentional incorrect responses(answering incorrectly).Results showed different activation patterns in the two conditions during the response execution and outcome feedback stage.Specifically,intentions to deceive showed significant deactivation in right DLPFC with respect to answering incorrectly.This showed that in the interactive situation,individuals put more cognitive efforts to mentalize the opponent's state of mind to anticipate his/her future behavior,so as to guide them to update the strategies.The results suggest that neural correlates of tell a lie are distinguishable from answering incorrectly.In experiment 4,in order to further improve the research of ecological validity,we used the interpersonal game to simulate real social situations,where two subjects face to face played guessing game coins under two conditions.Participants provided(un)truthful responses either on one's own initiative in the spontaneous condition or by following others' instructions in the instructed condition.It was found during the response execution stage,lying to deceive showed greater activation in prefrontal cortex and temporal parietal junction with respect to truth-telling to deceive under both spontaneous and instructed deception condition.This suggested that individuals need to suppress the truth and more psychological theories about what the other person is thinking when they tell lies.In the outcome feedback stage,the failure of deception resulted in the deactivation of the frontal pole and TPJ,compared with thesuccess feedback.Subjects might put more cognitive efforts to update their beliefs about the choices of other players through their experience and then choose their strategies.Taken together,the results suggest that the neural processes underlying deception in the frontoparietal network are associated with the psychological processes of deception,including cognitive control,theory of mind.These results were of great significance for understanding the deception process itself and its inherent neural mechanism,and provided opportunities for the application of lie detection.