Reward Promotes Self-Face Processing: An Event-Related Potential Study

Subjectively salient faces differ from emotional faces: ERP evidence

The self-face is processed differently than emotional faces. A question arises whether other highly familiar and subjectively significant non-self faces (e.g. partner's face) are also differentiated from emotional faces. The aim of this event-related potential (ERP) study was to investigate the neural correlates of personally-relevant faces (the self and a close-other's) as well as emotionally positive (happy) and neutral faces. Participants were tasked with the simple detection of faces. Amplitudes of N170 were more negative in the right than in the left hemisphere and were not modulated by type of face. A similar pattern of N2 and P3 results for the self-face and close-other's face was observed: they were associated with decreased N2 and increased P3 relative to happy and neutral faces. However, the self-face was preferentially processed also when compared to a close-other's face as revealed by lower N2 and higher P3 amplitudes. Nonparametric cluster-based permutation tests showed an analogous pattern of results: significant clusters for the self-face compared with all other faces (close-other's, happy, neutral) and for close-other's face compared to happy and neutral faces. In summary, the self-face prioritization was observed, as indicated by significant differences between one's own face and all other faces. Crucially, both types of personally-relevant faces differed from happy faces. These findings point to the pivotal role of subjective evaluation of the saliency factor.

Specificity in the processing of a subject's own name

Subject's own name (SON) is widely used in both daily life and the clinic. Event-related potential (ERP)-based studies have previously detected several ERP components related to SON processing; however, as most of these studies used SON as a deviant stimulus, it was not possible to determine whether these components were SON-specific. To identify SON-specific ERP components, we adopted a passive listening task with EEG data recording involving 25 subjects. The auditory stimuli were a SON, a friend's name (FN), an unfamiliar name (UN) selected from other subjects' names and seven different unfamiliar names (DUNs). The experimental settings included Equal-probabilistic, Frequent-SON, Frequent-FN and Frequent-UN conditions. The results showed that SON consistently evoked a frontocentral SON-related negativity (SRN) within 210-350 ms under all conditions, which was not detected with the other names. Meanwhile, a late positive potential evoked by SON was found to be affected by stimulus probability, showing no significant difference between the SON and the other names in the Frequent-SON condition, or between the SON and a FN in the Frequent-UN condition. Taken together, our findings indicated that the SRN was a SON-specific ERP component, suggesting that distinct neural mechanism underly the processing of a SON.

Interpersonal relationships modulate subjective ratings and electrophysiological responses of moral evaluations

This study explored how interpersonal relationships modulate moral evaluations in moral dilemmas. Participants rated moral acceptability in response to altruistic (prescriptive) and selfish (proscriptive) behavior conducted by allocators (i.e., a friend or stranger), toward the participants themselves or another stranger in a modified Dictator Game (Experiments 1 and 2). Event-related potential (ERP) data were recorded as participants observed the allocators' behavior (Experiment 2). Moral acceptability ratings showed that when the allocator was a friend, participants evaluated the friend's altruistic and selfish behavior toward another stranger as being less morally acceptable than when their friend showed the respective behavior toward the participants themselves. The ERP results showed that participants exhibited more negative medial frontal negativity (MFN) amplitude whether observing a friend's altruistic or selfish behavior toward a stranger (vs. participant oneself), indicating that friends' altruistic and selfish behaviors toward strangers (vs. participants) were processed as being less acceptable at the earlier and semi-automatic processing stage in brains. However, this effect did not emerge when the allocator was a stranger in subjective ratings and MFN results. In the later-occurring P3 component, no interpersonal relationship modulation occurred in moral evaluations. These findings suggest that interpersonal relationships affect moral evaluations from the second-party perspective.

Performance-dependent reward hurts performance: The non-monotonic attentional load modulation on task-irrelevant distractor processing

Selective attention is essential when we face sensory inputs with distractions. In the past decades, Lavie's load theory of selective attention delineates a complete picture of distractor suppression under different attentional control load. The present study was originally designed to explore how reward modulates the load effect of attentional selection. Unexpectedly, it revealed new findings under extended attentional load that was not involved in previous work. Participants were asked to complete a rewarded attentive visual tracking task while presented with irrelevant auditory oddball stimuli, with their behavioral performance, event-related potentials and pupillary responses recorded. We found that although the behavioral performance and pupil sizes varied unidirectionally with the attentional load, the processing of distractors as reflected by the mismatch negativity (MMN) increased first and then decreased. In contrast to the prediction of Lavie's theory that attentional control fails to effectively suppress distractor processing under high attentional control load, our finding suggests that extremely high attentional control load may instead require suppression of distractor processing at a stage as early as possible. Besides, P3a, a positive-polarity response sometimes following the MMN, was not affected by the attentional load, but both N1 (a negative-polarity component peaking ~100 ms from sound onset) and P3a were weakened at higher reward, indicating that reward leads to attenuated early processing of distractor and thus suppresses the attentional orienting towards distractors. These findings altogether complement Lavie's load theory of selective attention, presenting a more complex picture of how attentional load and reward affects selective attention.

Neural correlations of the influence of self-relevance on moral decision-making involving a trade-off between harm and reward

Although economists have suggested that humans generally prioritize maximizing their own self-interest rather than others' when distributing rewards, recent psychological studies have shown that people are hyperaltruistic when allocating physical harm to themselves and others during moral decision-making. However, little is known about how the neurocognitive mechanisms underlying self-relevance modulate this behavioral tendency under different degrees of physical harm. This study adopted a moral decision-making task to investigate behavioral and neural processes during moral decision-making involving different levels of self-relevance and physical harm. Event-related potentials were measured while participants made trade-offs of different monetary gains for themselves against painful electric shocks experienced by the receivers (self, friend, or stranger). These results suggest that early anterior N1, indexing fast and automatic moral intuitional process, decreased during the strong conflict trade-off decisions involving strong painful electric shocks and much monetary gains. Lower self-relevance enhanced the aversive experience and increased the mental cost of resolving moral conflict, reflected by a larger P260-LPP (300-450 ms) effect during weaker conflict decisions toward strangers than themselves and friends. However, this effect was weaker during strong conflict decisions. When making decisions about whether to shock others to gain money for themselves, participants were hyperaltruistic, foregoing greater self-interest to restrain harm directed toward strangers than themselves or friends. These findings shed light on the neural basis of the tension between egoistic and altruistic tendencies during moral decision-making integrating benefits and harms.

Influence of Self-Relevance and Reputational Concerns on Altruistic Moral Decision Making

Complex moral decision making may share certain cognitive mechanisms with economic decision making under risk situations. However, it is little known how people weigh gains and losses between self and others during moral decision making under risk situations. The current study adopted the dilemma scenario-priming paradigm to examine how self-relevance and reputational concerns influenced moral decision making. Participants were asked to decide whether they were willing to sacrifice their own interests to help the protagonist (friend, acquaintance, or stranger) under the dilemmas of reputational loss risk, while the helping choices, decision times and emotional responses were recorded. In Study 1, participants showed a differential altruistic tendency, indicating that participants took less time to make more helping choices and subsequently reported weaker unpleasant experience toward friends compared to acquaintances and strangers. In Study 2, participants still made these egoistically biased altruistic choices under the low reputational loss risk conditions. However, such an effect was weakened by the high reputational loss risks. Results suggested that moral principle guiding interpersonal moral decision making observed in our study is best described as an egoistically biased altruism, and that reputational concerns can play a key role in restraining selfish tendency.

The Influence of Self-Relevance and Cultural Values on Moral Orientation

Moral orientation refers to moral values that have a consistent guiding orientation toward an individual's moral cognition and behavior. Gilligan (1982) proposed that individuals have two moral orientations, namely “justice” and “care.” In the current study, we investigated the influence of self-relevance and cultural values on justice and care by using Single Attribute Implicit Association Test (SA-IAT). In Experiments 1 and 2, we adopted cultural icon prime paradigm to examine the effects of different self-referential stimuli (self, friend, and stranger) on implicit moral justice and care orientation under two cultural value conditions: traditionality, modernity, and neutral cultural values. Participants exhibited more difference toward different self-referential stimuli in the traditionality condition than in the modernity condition; the priming of traditional culture aggravated the differential order, whereas the priming of modernity weakened the differential order regarding implicitly just moral orientation. In the implicit care orientation, participants in the modern culture group exhibited the least difference to different self-referential stimuli compared with the other two groups, and the traditional group and the control group did not differ significantly. These findings indicate that psychological modernity weakens the degree of self-related effect in implicit justice and care orientation, whereas traditional culture aggravates the differential order in justice orientation. The current studies provide empirical support for theories relating moral orientation, also informing the literature on the role of self-relevance information and cultural values in moral decision making.

Distraction Modulates Self-Referential Effects in the Processing of Monetary and Social Rewards

A reward that is personally relevant tends to induce stronger pursuit motivation than a reward that is linked to other people. However, the role of attention in eliciting this “self-referential reward effect” remains unclear. In our two studies, we evaluated the significance of attention in self-referential reward processing utilizing an ownership paradigm, which required participants to complete a visual search task to win either monetary rewards (in Study 1) or social rewards (in Study 2) for themselves or for an acquaintance. Access to attentional resources was manipulated by sometimes including a distracting stimulus among the presented stimuli. The results of Study 1 revealed that a significant self-referential reward effect emerged under undistracted attentional conditions and was associated with improved task performance when self-owned monetary rewards were available. However, distracted attention impaired this self-referential reward effect. Moreover, distracted attention was also observed in the self-referential social reward processing in Study 2. These results suggested that distracted attention can impair the pursuit advantage for self-relevant rewards; self-referential processing is strongly dependent on attentional resources.

Consciously over Unconsciously Perceived Rewards Facilitate Self-face Processing: An ERP Study

Consciously and unconsciously perceived rewards are thought to modulate essential cognitive processes in different ways. However, little is known about whether and how they modulate higher-order social cognitive processes. The present ERP study aimed to investigate the effect of consciously and unconsciously perceived rewards on the temporal course of self-face processing. After a monetary reward (high or low) was presented either supraliminally or subliminally, participants gain this reward by rapidly and correctly judging whether the mouth shape of a probe face and a target face (self, friend, and stranger) were same. Results showed a significant three-way interaction between reward value, reward presentation type, and face type observed at the P3 component. For the supraliminal presentations, self-faces elicited larger P3 after high compared to low reward cues; however, friend-faces elicited smaller P3 and stranger-faces elicited equivalent P3 under this condition. For the subliminal presentations, self-faces still elicited larger P3 for high reward cues, whereas there were no significant P3 differences for friend-faces or stranger-faces. Together, these results suggest that consciously processed rewards have distinct advantages over unconsciously processed rewards in facilitating self-face processing by flexibly and effectively integrating reward value with self-relevance.