<h2 class="secHeading" id="section_abstract">Abstract</h2><p id="">It is controversial whether different cognitive functions can be mapped to discrete regions of the prefrontal cortex (PFC). The localisationist tradition has associated one cognitive function &ndash; inhibition &ndash; by turns with dorsolateral prefrontal cortex (DLPFC), inferior frontal cortex (IFC), or orbital frontal cortex (OFC). Inhibition is postulated to be a mechanism by which PFC exerts its effects on subcortical and posterior-cortical regions to implement executive control. We review evidence concerning inhibition of responses and task-sets. Whereas neuroimaging implicates diverse PFC foci, advances in human lesion-mapping support the functional localization of such inhibition to right IFC alone. Future research should investigate the generality of this proposed inhibitory function to other task domains, and its interaction within a wider network.</p>

<p id="">Survival can depend on the ability to change a current course of action to respond to potentially advantageous or threatening stimuli. This &ldquo;reorienting&rdquo; response involves the coordinated action of a right hemisphere dominant ventral frontoparietal network that interrupts and resets ongoing activity and a dorsal frontoparietal network specialized for selecting and linking stimuli and responses. At rest, each network is distinct and internally correlated, but when attention is focused, the ventral network is suppressed to prevent reorienting to distracting events. These different patterns of recruitment may reflect inputs to the ventral attention network from the locus coeruleus/norepinephrine system. While originally conceptualized as a system for redirecting attention from one object to another, recent evidence suggests a more general role in switching between networks, which may explain recent evidence of its involvement in functions such as social cognition.</p>

We used Near-Infrared Spectroscopy (NIRS) to simultaneously measure brain activity in two people while they played a computer-based cooperation game side by side. Inter-brain activity coherence was calculated between the two participants. We found that the coherence between signals generated by participants' right superior frontal cortices increased during cooperation, but not during competition. Increased coherence was also associated with better cooperation performance. To our knowledge, this work represents the first use of a single NIRS instrument for simultaneous measurements of brain activity in two people. This study demonstrates the use of NIRS-based hyperscanning in studies of social interaction in a naturalistic environment. (C) 2011 Elsevier Inc. All rights reserved.

Cognition materializes in an interpersonal space. The emergence of complex behaviors requires the coordination of actions among individuals according to a shared set of rules. Despite the central role of other individuals in shaping one's mind, most cognitive studies focus on processes that occur within a single individual. We call for a shift from a single-brain to a multi-brain frame of reference. We argue that in many cases the neural processes in one brain are coupled to the neural processes in another brain via the transmission of a signal through the environment. Brain-to-brain coupling constrains and shapes the actions of each individual in a social network, leading to complex joint behaviors that could not have emerged in isolation.

The present study aimed to step into two-person neuroscience by investigating the hemodynamic correlates of between-brain connectivity involved in imitation and its dependency on pacing stimuli. To test this approach, we used wireless functional near-infrared spectroscopy (fNIRS) to record simultaneously during imitation performance of a paced finger-tapping task (PFT) in two subjects over premotor cortices (PMC). During the imitation (IM) condition, a model and an imitator were recorded while tapping in synchrony with auditory stimuli separated by a constant interval (stimulus-paced mode, St-P), followed by tapping without the pacing stimulus (self-paced mode, Se-P). During the control (CO) condition, each subject (single 1 and 2) performed the PFT task with the same pacing mode pattern, but alone without reference to each other.<br/>Using wavelet transform coherence (WTC) analysis evaluating functional connectivity between brains, we found (1) that IM revealed a larger coherence increase between the model and the imitator as compared to the CO condition. (2) Within the IM condition, a larger coherence increase was found during Se-P as compared to St-P mode. Using Granger-causality (G-causality) analysis evaluating effective connectivity between brains, we found (3) that IM revealed larger G-causality as compared to the CO condition and (4) that within the IM condition, the signal of the model G-caused that of the imitator to a greater extent as compared to vice versa.<br/>Our findings designate fNIRS as suitable tool for monitoring between-brain connectivity during dynamic interactions between two subjects and that those measurements might thereby provide insight into activation patterns not detectable using typical single-person experiments. Overall, the results of the present study demonstrate the potential of simultaneously assessing brain hemodynamics in interacting subjects in several research areas where social interactions are involved. (C) 2012 Elsevier Inc. All rights reserved.

Although the human brain may have evolutionarily adapted to face-to-face communication, other modes of communication, e. g., telephone and e-mail, increasingly dominate our modern daily life. This study examined the neural difference between face-to-face communication and other types of communication by simultaneously measuring two brains using a hyperscanning approach. The results showed a significant increase in the neural synchronization in the left inferior frontal cortex during a face-to-face dialog between partners but none during a back-to-back dialog, a face-to-face monologue, or a back-to-back monologue. Moreover, the neural synchronization between partners during the face-to-face dialog resulted primarily from the direct interactions between the partners, including multi-modal sensory information integration and turn-taking behavior. The communicating behavior during the face-to-face dialog could be predicted accurately based on the neural synchronization level. These results suggest that face-to-face communication, particularly dialog, has special neural features that other types of communication do not have and that the neural synchronization between partners may underlie successful face-to-face communication.

<h2 class="secHeading" id="section_abstract">Abstract</h2><p id="sp0030">The role of mirror neuron systems and mentalising systems in causing poor social and communication skills in individuals with autistic spectrum conditions is hotly debated. We studied 18 adults with autistic spectrum conditions in comparison to 19 age and IQ matched typical individuals. Behavioural assessments revealed difficulties in mental state attribution and action comprehension in the autism sample. We examined brain responses when observing rational and irrational hand actions, because these actions engage mirror and mentalising components of the social brain respectively.</p><p id="sp0035">Both typical and autistic participants activated the left anterior intraparietal sulcus component of the mirror system when viewing hand actions compared to moving shapes. The typical but not autistic participants activated the posterior mid cingulate cortex/supplementary motor area and bilateral fusiform cortex when viewing hand actions. When viewing irrational hand actions, the medial prefrontal cortex of typical participants deactivated but this region did not distinguish the different stimuli in autistic participants. These results suggest that parietal mirror regions function normally in autism, while differences in action understanding could be due to abnormal function of cingulate, fusiform and medial prefrontal regions. Thus, brain regions associated with mirroring and mentalising functions are differentially affected in autistic spectrum conditions.</p><h4 id="secGabs_N37b60e90N3778f7d0">Research highlights</h4><p>? Adults with/without autism observed rational and irrational actions during fMRI. ? Anterior intraparietal sulcus showed equivalent responses in both groups. ? Supplementary motor area responded to action observation only in typicals. ? Medial prefrontal cortex differentiated action rationality only in typicals. ? Mirroring (aIPS) and mentalising (mPFC) brain area dissociate in autism.</p>

All known human societies have maintained social order by enforcing compliance with social norms. The biological mechanisms underlying norm compliance are, however, hardly understood. We show that the right lateral prefrontal cortex (rLPFC) is involved in both voluntary and sanction-induced norm compliance. Both types of compliance could be changed by varying the neural excitability of this brain region with transcranial direct current stimulation, but they were affected in opposite ways, suggesting that the stimulated region plays a fundamentally different role in voluntary and sanction-based compliance. Brain stimulation had a particularly strong effect on compliance in the context of socially constituted sanctions, whereas it left beliefs about what the norm prescribes and about subjectively expected sanctions unaffected. Our findings suggest that rLPFC activity is a key biological prerequisite for an evolutionarily and socially important aspect of human behavior.

<p id="">Compliance with social norms requires neural signals related both to the norm and to deviations from it. Recent work using economic games between two interacting subjects has uncovered brain responses related to norm compliance and to an individual's strategic outlook during the exchange. These brain responses possess a provocative relationship to those associated with negative emotional outcomes, and hint at computational depictions of emotion processing.</p>

Humans are willing to punish norm violations even at a substantial personal cost. Using fMRI and a variant of the ultimatum game and functional magnetic resonance imaging, we investigated how the brain differentially responds to fairness in loss and gain domains. Participants (responders) received offers from anonymous partners indicating a division of an amount of monetary gain or loss. If they accept, both get their shares according to the division; if they reject, both get nothing or lose the entire stake. We used a computational model to derive perceived fairness of offers and participant-specific inequity aversion. Behaviorally, participants were more likely to reject unfair offers in the loss (vs gain) domain. Neurally, the positive correlation between fairness and activation in ventral striatum was reduced, whereas the negative correlations between fairness and activations in dorsolateral prefrontal cortex were enhanced in the loss domain. Moreover, rejection-related dorsal striatum activation was higher in the loss domain. Furthermore, the gain-loss domain modulates costly punishment only when unfair behavior was directed toward the participants and not when it was directed toward others. These findings provide neural and computational accounts of increased costly norm enforcement under adversity and advanced our understanding of the context-dependent nature of fairness preference.

In human society, sharing losses is at least as common as sharing gains. Although the psychological and neural processes underlying the latter have been investigated in depth, those related to the former are not clear. Our recent study demonstrates an increased demand for fairness under adversity (e.g. loss sharing). Here we investigated how our brain encodes unfairness in the loss and gain domains using event-related potentials (ERP) technique. We adopted the Ultimatum Game (UG) to probe the processes related to fairness consideration in either gain or loss domain. In UG, two players, the proposer and the responder, bargain on how to divide a certain amount of money endowed by the experimenter. The proposer suggests a division policy, on which the responder evaluates and decides whether to accept. Upon acceptance, the money is divided as suggested; while rejection results in both players going empty-handed. Participants, as responders, were required to decide whether to accept an offer that was either fair (equal or nearly equal division) or unfair in both gain and loss domain. Offers were either made by the human partner or by the computer partner. Behavioral results replicated our previous findings that the rejection rate of unfair offers was higher in the loss than in the gain domain. ERP results revealed that the N1 amplitude was more pronounced for human partners compared with computer partners, however, this effect was only observed in the gain domain. When interacting with computer partners, unfair offers and offers in the loss domain were associated with larger N350 compared with fair offers and offers in the gain domain, and offers in the gain domain elicited larger P2 than offers in the loss domain, whereas fair offers and offers in the gain domain were associated with larger LPP than unfair offers and offers in the loss domain. In addition, these differences in ERP responses were diminished when the interacting partners were humans. These findings suggest that fairness processing is modulated by the property of the partner and gain-loss domain. In human-computer interaction, unfair offers and offers in the loss domain elicit more inhibition and conflict resolving process, while fair offers and offers in the gain domain are more motivationally significant to human. The present findings support the view that fairness processing is context-dependent, in which factors like gain-loss domain and the property of the partner play a role.

公平是人类社会生活的重要概念。大量研究采用最后通牒博弈, 发现人们具有不公平厌恶倾向, 即宁愿牺牲个人的经济利益, 也要拒绝不公平的分配提议。已有研究表明, 损失情境会增强不公平厌恶, 但其神经机制尚不清楚。本实验采用ERP技术, 运用最后通牒博弈范式, 考察两个情境因素：域(损失或获益)和博弈对象(人或计算机)对公平加工的影响。发现损失域下对不公平分配的拒绝率更高, 而博弈对象对决策行为无影响; 获益域下, 对家为人比对家为计算机诱发了更负的N1; 人机博弈时, 获益域比损失域诱发了更大的P2和LPP, 损失域比获益域、不公平提议比公平提议诱发了更大的N350, 而公平提议比不公平提议诱发了更大的LPP; 人际博弈时, 这些差异均不显著。这些结果表明, 对分配提议的大脑加工受博弈对象的调节, 人际博弈时, 对损益域、公平与不公平提议的加工类似, 而人机博弈时, 损失域和不公平提议涉及更多的抑制加工和冲突解决, 获益域和公平提议则更富动机性意义, 证实公平加工具有情境依赖性。

<h2 class="secHeading" id="section_abstract">Abstract</h2><p id="">Near infrared spectroscopy (NIRS) is a non-invasive method to measure brain activity via changes in the degree of hemoglobin oxygenation through the intact skull. As optically measured hemoglobin signals strongly correlate with BOLD signals, simultaneous measurement using NIRS and fMRI promises a significant mutual enhancement of temporal and spatial resolutions. Although there exists a powerful statistical parametric mapping tool in fMRI, current public domain statistical tools for NIRS have several limitations related to the quantitative analysis of simultaneous recording studies with fMRI. In this paper, a new public domain statistical toolbox known as NIRS-SPM is described. It enables the quantitative analysis of NIRS signal. More specifically, NIRS data are statistically analyzed based on the general linear model (GLM) and Sun's tube formula. The <em>p</em>-values are calculated as the excursion probability of an <em>inhomogeneous</em> random field on a representation manifold that is dependent on the structure of the error covariance matrix and the interpolating kernels. NIRS-SPM not only enables the calculation of activation maps of oxy-, deoxy-hemoglobin and total hemoglobin, but also allows for the super-resolution localization, which is not possible using conventional analysis tools. Extensive experimental results using finger tapping and memory tasks confirm the viability of the proposed method.</p>

<h2 class="secHeading" id="section_abstract">Abstract</h2><p id="">Moral judgment in the mature state depends on &ldquo;theory of mind&rdquo;, or the capacity to attribute mental states (e.g., beliefs, desires, and intentions) to moral agents. The current study uses functional magnetic resonance imaging (fMRI) to investigate the cognitive processes for belief attribution in moral judgment. Participants read vignettes in a 2&#xA0;&times;&#xA0;2&#xA0;&times;&#xA0;2 design: protagonists produced either a negative or neutral outcome, based on the belief that they were causing the negative outcome or the neutral outcome; presentation of belief information either preceded or followed outcome information. In each case, participants judged the moral permissibility of the action. The results indicate that while the medial prefrontal cortex is recruited for processing belief valence, the temporo-parietal junction and precuneus are recruited for processing beliefs in moral judgment via two distinct component processes: (1) encoding beliefs and (2) integrating beliefs with other relevant features of the action (e.g., the outcome) for moral judgment.</p>