A Study On The Differences Between Implicit And Explicit Moral Processing

Morality roles as the fundamental components of human nature across cultures because it is considered as the sets of customs and values that are embraced by a cultural group to guide social conduct.Exploring neural mechanisms underlying moral processing would provide an important basis for intention’s understanding and discrimination of human-computer interaction under complex situations.Moral processing is catalogued into explicit and implicit moral processing based on intentional and unintentional manner.Recently,researchers have explored the neural mechanisms underlying explicit moral processing through a variety of advanced technology.It was emphasized from theoretical models and empirical results that explicit moral processing is the result of competition or interaction between cognition and emotion.However,to date there are two arguments on moral processing.Firstly,moral processing might be involved in both explicit and implicit moral processing.Neither implicit nor explicit moral processing is a "pure process",both types of cognitive processes may include automatic assessment,executive control,or both two processes.Moral information does not always lead to explicit moral judgment,but a few studies have explored implicit moral processing.Secondly,it is not correct to completely separate emotional intuition from cognitive processes at the biological level or mental level.In brief,how emotion and cognition play a role in implicit and explicit moral processing is still unclear,and the difference between the two types of moral processing in neural mechanism is still unknown.This study aimed to explore the differences between implicit and explicit moral processing in behavioral performance and neural mechanism from time and spatial dimensions.This study modified the current task paradigms of implicit and explicit morals and considered emotional arousal and moral valence as independent factors in three experiments for exploring the differences between the two kinds of moral processing.The three experiments all adopted the same experimental design with the same moral context in the intentional and unintentional forms where the subjects are divided into two groups one of which performed the “explicit moral task” and the others performed the “implicit moral task”.In the explicit task,the participants were instructed to determine whether the picture represented moral or immoral behavior,whereas in the implicit task,the participants were instructed to determine whether kids or animals presented in the picture,and at the same time take emotional arousal and moral valence as independent factors.This study explored the difference between the two kinds of moral processing in the same moral context in the form of intentional and unintentional.Experiment 1 was designed to examine the difference in behavioral performance between the two kinds of moral processing,and experiment 2 and experiment 3 were designed to investigate the difference in the neural mechanisms underlying explicit and implicit moral processing by using EEG/ERP,eye movement and f MRI techniques,respectively.The behavioral results from experiment 1 showed that accuracy was higher in the explicit moral task than in the implicit moral task,specifically for the high-arousal moral action,indicating that implicit moral processing may consume more mental resources and that morally good information with high arousal can promote explicit moral processing.The reaction time was longer in the explicit task than in the implicit task,indicating that moral processing in the explicit task might be more difficult.In the explicit task,the reaction time on processing moral pictures was longer than that on immoral pictures,but the reaction time in the implicit task showed the opposite pattern,indicating that moral valence exerts the effect on the implicit and explicit moral processing in the opposite way.In addition,reaction time was longer in processing low-arousal pictures,indicating that processing low-arousal pictures in both implicit and explicit moral tasks required more time.These behavioral results implied that there are differences between implicit and explicit moral processing and that moral valence and emotional arousal are important factors that affect both two processes.The eye tracking results from experiment 2 revealed that the first fixation time was shorter on moral pictures than on immoral pictures,indicating that processing immoral scenes consumes more cognition resources to keep attentions.There was no significant difference in dwell time at the early stage of processing between explicit and implicit tasks.In implicit task,the dwell time at the late stage was longer on immoral pictures than on moral pictures,but it was not true in explicit task.In addition,pupil dilation was significantly larger in the late stage than in the middle stage in implicit task,while in the explicit task,the pupil dilation became larger and larger with the increase of the time course,indicating that similar processing patterns existing in the implicit and explicit moral processing,but the devotion of emotional and cognitive resources in implicit moral processing may have a lag in time.These results implied that there are interactions between consciousness and unconsciousness in both implicit and explicit moral processing,but implicit moral processing may have a lag in time.ERP results showed that the N1,P2,P3,LPP and FSW amplitude were greater for high emotional arousal stimuli than for low emotional arousal stimuli,and moral stimuli and immoral stimuli differed in P2,N2,P3,LPP and FSW component,indicating that the EEG responses to moral processing in both explicit or implicit moral contain early auto-processing of emotional arousal indexed by the frontal N1,and moral intuition indexed by the frontal N2,and middle and late stages showing interaction between emotional arousal and moral cognition reflected by the frontal P2,P3,LPP,and FSW components.The later moral cognition involving inhibition control indexed by the FSW,and attentional resource allocation and elaborative processing indexed by the P3 and LPP can differentiate explicit and implicit moral tasks,with enhanced amplitudes in difference wave for moral valence during the implicit task than during the explicit task.Such results suggested that implicit moral processing may exhaust more mental resources during the late stage of neural processing of moral processing,and morally good information with high arousal can promote explicit moral processing.s LORETA results showed that compared with explicit task,more activated in areas related with the inferior frontal gyrus(IFG)and middle frontal gyrus(MFG)in implicit task,MFG is thought to be involved in mentalizing,inhibitory processes,and attentional control.The time-frequency results showed that theta increased in the frontal area during implicit task,frontal theta is related to cognitive control.When a large amount of executive function resources is required,the energy increases,this result indicated that more cognitive control resources are required during implicit moral processing.Results from Experiment 3 showed that during the explicit task,individuals were associated with increased activity in the precentral and supplementary motor area(SMA),while in the implicit task,individuals predicted increased signal change in inferior frontal gyrus(IFG)and left caudate nucleus,suggesting that implicit moral processing requires stronger attention control and emotional suppression.In addition,in the explicit task,high-arousal pictures were more activated in areas related with negative emotion like the anterior insula(AI)and amygdala,immoral pictures were more activated in areas related with cognitive control like the temporal parietal junction region(TPJ)and right superior temporal gyrus(p STS).In the implicit task,high-arousal pictures were more activated in areas related with not only emotion-related brain areas including the anterior cingulate gyrus(ACC)but also associated with cognitive control brain areas such as the ventrolateral prefrontal lobe,immoral pictures were more activated in areas related with not only emotion-related brain areas including the PCC,ventromedial prefrontal cortex(vm PFC)and AI but also associated with cognitive control brain areas such as the p STS and TPJ,indicating that both explicit and implicit moral processing were affected by moral valence and emotional arousal,which was manifested in that immoral and high-arousal information requires more cognitive attention and emotional process resources.In summary,this study strongly supports the multinomial model,implicit and explicit moral processing are two independent processes.Both two processing include emotional intuition and moral cognitive processes from the aspect of space and time,but implicit moral processing requires more cognitive control,attentional resource,and elaborative processing.