Intention Modulates the Effect of Punishment Threat in Norm Enforcement via the Lateral Orbitofrontal Cortex.

UNLABELLED: Although economic theories suggest that punishment threat is crucial for maintaining social norms, counterexamples are noted in which punishment threat hinders norm compliance. Such discrepancy may arise from the intention behind the threat: unintentionally introduced punishment threat facilitates, whereas intentionally introduced punishment threat hinders, norm compliance. Here, we combined a dictator game and fMRI to investigate how intention modulates the effect of punishment threat on norm compliance and the neural substrates of this modulation. We also investigated whether this modulation can be influenced by brain stimulation. Human participants divided an amount of money between themselves and a partner. The partner (intentionally) or a computer program (unintentionally) decided to retain or waive the right to punish the participant upon selfish distribution. Compared with the unintentional condition, participants allocated more when the partner intentionally waived the power of punishment, but less when the partner retained such power. The right lateral orbitofrontal cortex (rLOFC) showed higher activation when the partner waived compared with when the computer waived or when the partner retained the power. The functional connectivity between the rLOFC and the brain network associated with intention/mentalizing processing was predictive of the allocation difference induced by intention. Moreover, inhibition or activation of the rLOFC by brain stimulation decreased or increased, respectively, the participants' reliance on the partner's intention during monetary allocation. These findings demonstrate that the perceived intention of punishment threat plays a crucial role in norm compliance and that the LOFC is casually involved in the implementation of intention-based cooperative decisions. SIGNIFICANCE STATEMENT: Does punishment threat facilitate or hinder norm enforcement? So far, cognitive neuroscience research offers equivocal evidence. By directly manipulating the intention behind punishment threat, we demonstrate that intention modulates the effectiveness of punishment threat. Moreover, we show that inhibition or activation of the right lateral orbitofrontal cortex (rLOFC) decreased or increased the effect of punishment threat in the intentional context, but not in the unintentional context, suggesting the casual involvement of the rLOFC in intention-based cooperative decisions.

How do self-interest and other-need interact in the brain to determine altruistic behavior?

Altruistic behavior, i.e., promoting the welfare of others at a cost to oneself, is subserved by the integration of various social, affective, and economic factors represented in extensive brain regions. However, it is unclear how different regions interact to process/integrate information regarding the helper's interest and recipient's need when deciding whether to behave altruistically. Here we combined an interactive game with functional Magnetic Resonance Imaging (fMRI) and transcranial direct current stimulation (tDCS) to characterize the neural network underlying the processing/integration of self-interest and other-need. At the behavioral level, high self-risk decreased helping behavior and high other-need increased helping behavior. At the neural level, activity in medial prefrontal cortex (MPFC) and right dorsolateral prefrontal cortex (rDLPFC) were positively associated with self-risk levels, and activity in right inferior parietal lobe (rIPL) and rDLPFC were negatively associated with other-need levels. Dynamic causal modeling further suggested that both MPFC and rIPL were extrinsically connected to rDLPFC; high self-risk enhanced the effective connectivity from MPFC to rDLPFC, and the modulatory effect of other-need on the connectivity from rIPL to rDLPFC positively correlated with the modulatory effect of other-need on individuals' helping rate. Two tDCS experiments provided causal evidence that rDLPFC affects both self-interest and other-need concerns, and rIPL selectively affects the other-need concerns. These findings suggest a crucial role of the MPFC-IPL-DLPFC network during altruistic decision-making, with rDLPFC as a central node for integrating and modulating motives regarding self-interest and other-need.

Lateral prefrontal/orbitofrontal cortex has different roles in norm compliance in gain and loss domains: a transcranial direct current stimulation study.

Sanction is used by almost all known human societies to enforce fairness norm in resource distribution. Previous studies have consistently shown that the lateral prefrontal cortex (lPFC) and the adjacent orbitofrontal cortex (lOFC) play a causal role in mediating the effect of sanction threat on norm compliance. However, most of these studies were conducted in gain domain in which resources are distributed. Little is known about the mechanisms underlying norm compliance in loss domain in which individual sacrifices are needed. Here we employed a modified version of dictator game (DG) and high-definition transcranial direct current stimulation (HD-tDCS) to investigate to what extent lPFC/lOFC is involved in norm compliance (with and without sanction threat) in both gain- and loss-sharing contexts. Participants allocated a fixed total amount of monetary gain or loss between themselves and an anonymous partner in multiple rounds of the game. A computer program randomly decided whether a given round involved sanction threat for the participants. Results showed that disruption of the right lPFC/lOFC by tDCS increased the voluntary norm compliance in the gain domain, but not in the loss domain; tDCS on lPFC/lOFC had no effect on compliance under sanction threat in either the gain or loss domain. Our findings reveal a context-dependent nature of norm compliance and differential roles of lPFC/lOFC in norm compliance in gain and loss domains.

High-definition tDCS alters impulsivity in a baseline-dependent manner.

In intertemporal choice (ITC), people discount future rewards in proportion to the time delay until reward receipt. Despite recent non-invasive brain stimulation studies suggesting a general causal link between dorsolateral prefrontal cortex (dlPFC) activity and ITC impulsivity, results regarding the functional specificity of dlPFC are mixed. We used high-definition transcranial direct current stimulation (HD-tDCS) to map changes in causal impulsivity through bi-directional modulation of left and right dlPFC during ITC. Model-free and model-based analyses demonstrated that anodal and cathodal stimulation of left dlPFC, but not right dlPFC, decreased and increased impulsivity, respectively. Critically, an individual differences analysis revealed that modulation of impulsivity was contingent on participants' baseline impulsivity. Overall, our results might reconcile the discrepancies in the existing literature and suggest a baseline-dependent role for left dlPFC during ITC.

A tale of two narratives: The role of event disruption in employee affective and behavioral reactions to authoritarian leadership.

Extant research demonstrates the destructive nature of authoritarian leadership in the workplace, yet its widespread use suggests that a more balanced view of this leadership style may be needed to identify whether this form of leadership engenders favorable reactions in specific circumstances. Integrating insights from appraisal theory and the compensatory control model, we posit that authoritarian leadership can evoke anxiety among employees in less disruptive settings, whereas it evokes feelings of awe in highly disruptive contexts. These anxiety and awe reactions then influence employees' downstream leader-focused behaviors (i.e., leader-directed avoidance and affiliation) and general work behaviors (i.e., counterproductive behavior and job performance). Thus, whether reactions to authoritarian leadership are dysfunctional or functional is contingent on event disruption as a key boundary condition. Results from an experience sampling study (Study 1), a multiwave and multisource field study (Study 2), and laboratory experiments (Studies 3a and 3b) largely confirm these predictions. The findings underscore the importance of event disruption for predicting employee reactions to authoritarian styles of leadership. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Hematite-promoted nitrate-reducing Fe(II) oxidation by Acidovorax sp. strain BoFeN1: Roles of mineral catalysis and cell encrustation.

Although nitrate-reducing Fe(II) oxidizing (NRFO) bacteria can grow sustainably in natural environments, numerous laboratory studies suggested that cell encrustation-induced metabolism limitations and cell death occurred more seriously in the absence of natural minerals. Hence, a study on how natural minerals could affect NRFO is warranted. This study examined the impact of hematite on NRFO by Acidovorax sp. BoFeN1 with different electron donors (acetate and Fe(II), acetate alone, and Fe(II) alone) and with nitrate as an electron acceptor. When acetate and Fe(II) were used as the electron donors, the amount of Fe(II) oxidation and nitrate reduction was enhanced in the presence of hematite, whereas no promotion was observed when only acetate was added as an electron donor. Under the conditions with only Fe(II) added as an electron donor, the level of Fe(II) oxidation was increased from 3.07 ± 0.06 to 3.92 ± 0.02 mM in the presence of hematite and nitrate reduction was enhanced. This suggests that hematite promotes microbial nitrate reduction by accelerating the biological oxidation of Fe(II). The main secondary minerals were goethite and lepidocrocite. After adding hematite, the assemblage of iron minerals on the cell surface decreased, and the cell crusts became thinner, indicating that hematite effectively mitigated cell encrustation. Furthermore, hematite accelerated the chemical oxidation of Fe(II) by nitrite. Hence, hematite can promote the NRFO of Acidovorax sp. BoFeN1 via two possible pathways: (i) hematite acts as nucleation sites to mitigate cell encrustation; (ii) hematite catalyzes the biological and chemical oxidation of Fe(II) through the mineral catalysis effects. This study highlights the importance of existing iron minerals on NRFO and sheds light on the survival strategy of NRFO bacteria in anoxic subsurface environments.

Promoting subjective preferences in simple economic choices during nap.

Sleep is known to benefit consolidation of memories, especially those of motivational relevance. Yet, it remains largely unknown the extent to which sleep influences reward-associated behavior, in particular, whether and how sleep modulates reward evaluation that critically underlies value-based decisions. Here, we show that neural processing during sleep can selectively bias preferences in simple economic choices when the sleeper is stimulated by covert, reward-associated cues. Specifically, presenting the spoken name of a familiar, valued snack item during midday nap significantly improves the preference for that item relative to items not externally cued. The cueing-specific preference enhancement is sleep-dependent and can be predicted by cue-induced neurophysiological signals at the subject and item level. Computational modeling further suggests that sleep cueing accelerates evidence accumulation for cued options during the post-sleep choice process in a manner consistent with the preference shift. These findings suggest that neurocognitive processing during sleep contributes to the fine-tuning of subjective preferences in a flexible, selective manner.