Honghong Tang

Interpersonal brain synchronization in the right temporo-parietal junction during face-to-face economic exchange

In daily life, interpersonal interactions are influenced by uncertainty about other peoples intentions. Face-to-face (FF) interaction reduces such uncertainty by providing external visible cues such as facial expression or body gestures and facilitates shared intentionality to promote belief of cooperative decisions and actual cooperative behaviors in interaction. However, so far little is known about interpersonal brain synchronization between two people engaged in naturally occurring FF interactions. In this study, we combined an adapted ultimatum game with functional near-infrared spectroscopy (fNIRS) hyperscanning to investigate how FF interaction impacts interpersonal brain synchronization during economic exchange. Pairs of strangers interacted repeatedly either FF or face-blocked (FB), while their activation was simultaneously measured in the right temporo-parietal junction (rTPJ) and the control region, right dorsolateral prefrontal cortex (rDLPFC). Behaviorally, FF interactions increased shared intentionality between strangers, leading more positive belief of cooperative decisions and more actual gains in the game. FNIRS results indicated increased interpersonal brain synchronizations during FF interactions in rTPJ (but not in rDLPFC) with greater shared intentionality between partners. These results highlighted the importance of rTPJ in collaborative social interactions during FF economic exchange and warrant future research that combines FF interactions with fNIRS hyperscanning to study social brain disorders such as autism.

Dissociable Somatotopic Representations of Chinese Action Verbs in the Motor and Premotor Cortex

The embodied view of language processing holds that language comprehension involves the recruitment of sensorimotor information, as evidenced by the somatotopic representation of action verbs in the motor system. However, this review has not yet been examined in logographic scripts such as Chinese, in which action verbs can provide explicit linguistic cues to the effectors (arm, leg, mouth) that conduct the action (hit, jump, drink). We compared the somatotopic representation of Chinese verbs that contain such effector cues and those that do not. The results showed that uncued verbs elicited similar somatotopic representation in the motor and premotor cortex as found in alphabetic scripts. However, effector-cued verbs demonstrated an inverse somatotopic pattern by showing reduced activation in corresponding motor areas, despite that effector-cued verbs actually are rated higher in imageability than uncued verbs. Our results support the universality of somatotopic representation of action verbs in the motor system.

Multi-Representation of Symbolic and Nonsymbolic Numerical Magnitude in Chinese Number Processing

Numerical information can be conveyed by either symbolic or nonsymbolic representation. Some symbolic numerals can also be identified as nonsymbolic quantities defined by the number of lines (e.g., I, II, III in Roman and , , in Japanese Kanji and Chinese). Here we report that such multi-representation of magnitude can facilitate the processing of these numerals under certain circumstances. In a magnitude comparison task judging 1 to 9 (except 5) Chinese and Arabic numerals presented at the foveal (at the center) or parafoveal (3° left or right of the center) location, multi-representational small-value Chinese numerals showed a processing advantage over single-representational Arabic numerals and large-value Chinese numerals only in the parafoveal condition, demonstrated by lower error rates and faster reaction times. Further event-related potential (ERP) analysis showed that such a processing advantage was not reflected by traditional ERP components identified in previous studies of number processing, such as N1 or P2p. Instead, the difference was found much later in a N400 component between 300–550 msec over parietal regions, suggesting that those behavioral differences may not be due to early processing of visual identification, but later processing of subitizing or accessing mental number line when lacking attentional resources. These results suggest that there could be three stages of number processing represented separately by the N1, P2p and N400 ERP components. In addition, numerical information can be represented simultaneously by both symbolic and nonsymbolic systems, which will facilitate number processing in certain situations.

Temporal Dynamics of the Integration of Intention and Outcome in Harmful and Helpful Moral Judgment

The ability to integrate the moral intention information with the outcome of an action plays a crucial role in mature moral judgment. Functional magnetic resonance imaging (fMRI) studies implicated that both prefrontal and temporo-parietal cortices are involved in moral intention and outcome processing. Here, we used the event-related potentials (ERPs) technique to investigate the temporal dynamics of the processing of the integration between intention and outcome information in harmful and helpful moral judgment. In two experiments, participants were asked to make moral judgments for agents who produced either negative/neutral outcomes with harmful/neutral intentions (harmful judgment) or positive/neutral outcomes with helpful/neutral intentions (helpful judgment). Significant ERP differences between attempted and successful actions over prefrontal and bilateral temporo-parietal regions were found in both harmful and helpful moral judgment, which suggest a possible time course of the integration processing in the brain, starting from the right temporo-parietal area (N180) to the left temporo-parietal area (N250), then the prefrontal area (FSW) and the right temporo-parietal area (TP450 and TPSW) again. These results highlighted the fast moral intuition reaction and the late integration processing over the right temporo-parietal area.

Self-Punishment Promotes Forgiveness in the Direct and Indirect Reciprocity Contexts

Most previous studies regarding self-punishment have focused on the correlation between moral emotion and self-punishment. Only a few studies have attempted to understand self-punishment from the perspective of seeking forgiveness, and no study has yet directly tested whether wrongdoers’ self-punishment promotes others to forgive the wrongdoers. In three studies, the participants judged the wrongdoers’ self-punishment behaviors following an unfair allocation and reported the extent to which they forgave the wrongdoers. The results demonstrated that self-punishment did promote forgiveness in both the direct (Studies 1 and 2) and indirect reciprocity (Study 3) contexts. Consistent with costly signaling theory, the costlier the self-punishment was, the stronger the effect it had on forgiveness. Moreover, communicative self-punishment had a better effect than silent self-punishment when the cost was relatively high in the direct-reciprocity studies. These findings can guide us regarding how to address a damaged relationship via self-punishment when compensation is not feasible or acceptable.

The effect of shame on anger at others: awareness of the emotion-causing events matters

ABSTRACT Numerous studies have found that shame increases individuals’ anger at others. However, according to recent theories about the social function of shame and anger at others, it is possible that shame controls individuals’ anger at others in specific conditions. We replicated previous findings that shame increased individuals’ anger at others’ unfairness, when others were not aware of the individual’s experience of shameful events. We also found for the first time that shame controlled or even decreased individuals’ anger at others’ unfairness, when others were aware of the individual’s experience of shameful events. The results were consistent when shame was induced by either a recall paradigm or an imagination paradigm, and in either the ultimatum game or the dictator game. This suggests that shame strategically controls individuals’ anger at others to demonstrate that they are willing to benefit others, when facing the risk of social exclusion. Our findings highlight the interpersonal function of shame and deepen the understanding of the relationship between shame and anger at others.

Washing away your sins in the brain: physical cleaning and priming of cleaning recruit different brain networks after moral threat

Abstract The association between moral purity and physical cleanliness has been widely discussed recently. Studies found that moral threat initiates the need of physical cleanliness, but actual physical cleaning and priming of cleaning have inconsistent effects on subsequent attitudes and behaviors. Here, we used resting-state functional magnetic resonance imaging to explore the underlying neural mechanism of actual physical cleaning and priming of cleaning. After recalling moral transgression with strong feelings of guilt and shame, participants either actually cleaned their faces with a wipe or were primed with cleanliness through viewing its pictures. Results showed that actual physical cleaning reduced the spontaneous brain activities in the right insula and MPFC, regions that involved in embodied moral emotion processing, while priming of cleaning decreased activities in the right superior frontal gyrus and middle frontal gyrus, regions that participated in executive control processing. Additionally, actual physical cleaning also changed functional connectivity between insula/MPFC and emotion related regions, whereas priming of cleaning modified connectivity within both moral and sensorimotor areas. These findings revealed that actual physical cleaning and priming of cleaning led to changes in different brain regions and networks, providing neural evidence for the inconsistent effects of cleanliness on subsequent attitudes and behaviors.

Object words modulate the activity of the mirror neuron system during action imitation

Although research has demonstrated that the mirror neuron system (MNS) plays a crucial role in both action imitation and action‐related semantic processing, whether action‐related words can inversely modulate the MNS activity remains unclear.

Early distinction between shame and guilt processing in an interpersonal context

ABSTRACT Shame and guilt have been compared in many behavioral and functional magnetic resonance imaging studies. However, the time course of shame and guilt processing remains unknown. We conducted an event-related potential (ERP) study to investigate the temporal dynamics of shame and guilt in an interpersonal context. Behaviorally, participants reported “shame” when their wrong advice was correctly rejected by a confederate, whereas reported “guilt” when their wrong advice resulted in economic loss of a confederate. The ERP results showed significant difference between the shame and guilt conditions in the early P2 component (140–220 ms) over the frontal region and the alpha oscillations (240–1000 ms) over the parietal region. No significant difference was found between the shame and guilt conditions in the N2, P3, and theta oscillations. These results supported previous findings that shame compared to guilt involves more self-referential processing, whereas guilt compared to shame involves more empathetic processing, and provided evidence that the distinction between shame and guilt could occur in an early stage.

Stimulating the Right Temporoparietal Junction with tDCS Decreases Deception in Moral Hypocrisy and Unfairness

Self-centered and other-regarding concerns play important roles in decisions of deception. To investigate how these two motivations affect deception in fairness related moral hypocrisy, we modulated the brain activity in the right temporoparietal junction (rTPJ), the key region for decision making involved in self-centered and other-regarding concerns. After receiving brain stimulation with transcranial direct current stimulation (tDCS), participants finished a modified dictator game. In the game, they played as proposers to make allocations between themselves and recipients and had a chance to deceive by misreporting their totals for allocations. Results show that deception in moral hypocrisy was decreased after anodal stimulation than sham and cathodal stimulation, only when participants know that their reported totals (appearing fair) would be revealed to recipients rather than being unrevealed. Anodal stimulation also increased offers to recipients than cathodal stimulation regardless of the revelation of reported totals. These findings suggest that enhancing the activity of rTPJ decreased deception caused by impression management rather than self-deception in moral hypocrisy and unfairness through facilitating other-regarding concerns and weakening non-material self-centered motivations. They provide causal evidence for the role of rTPJ in both other-regarding concerns and non-material self-centered motivations, shedding light on the way to decrease moral hypocrisy.