Neural correlates of adaptive social responses to real-life frustrating situations: a functional MRI study.

BACKGROUND: Frustrating situations are encountered daily, and it is necessary to respond in an adaptive fashion. A psychological definition states that adaptive social behaviors are "self-performing" and "contain a solution." The present study investigated the neural correlates of adaptive social responses to frustrating situations by assessing the dimension of causal attribution. Based on attribution theory, internal causality refers to one's aptitudes that cause natural responses in real-life situations, whereas external causality refers to environmental factors, such as experimental conditions, causing such responses. To investigate the issue, we developed a novel approach that assesses causal attribution under experimental conditions. During fMRI scanning, subjects were required to engage in virtual frustrating situations and play the role of protagonists by verbalizing social responses, which were socially adaptive or non-adaptive. After fMRI scanning, the subjects reported their causal attribution index of the psychological reaction to the experimental condition. We performed a correlation analysis between the causal attribution index and brain activity. We hypothesized that the brain region whose activation would have a positive and negative correlation with the self-reported index of the causal attributions would be regarded as neural correlates of internal and external causal attribution of social responses, respectively. RESULTS: We found a significant negative correlation between external causal attribution and neural responses in the right anterior temporal lobe for adaptive social behaviors. CONCLUSION: This region is involved in the integration of emotional and social information. These results suggest that, particularly in adaptive social behavior, the social demands of frustrating situations, which involve external causality, may be integrated by a neural response in the right anterior temporal lobe.

Self-face recognition in social context.

The concept of "social self" is often described as a representation of the self-reflected in the eyes or minds of others. Although the appearance of one's own face has substantial social significance for humans, neuroimaging studies have failed to link self-face recognition and the likely neural substrate of the social self, the medial prefrontal cortex (MPFC). We assumed that the social self is recruited during self-face recognition under a rich social context where multiple other faces are available for comparison of social values. Using functional magnetic resonance imaging (fMRI), we examined the modulation of neural responses to the faces of the self and of a close friend in a social context. We identified an enhanced response in the ventral MPFC and right occipitoparietal sulcus in the social context specifically for the self-face. Neural response in the right lateral parietal and inferior temporal cortices, previously claimed as self-face-specific, was unaffected for the self-face but unexpectedly enhanced for the friend's face in the social context. Self-face-specific activation in the pars triangularis of the inferior frontal gyrus, and self-face-specific reduction of activation in the left middle temporal gyrus and the right supramarginal gyrus, replicating a previous finding, were not subject to such modulation. Our results thus demonstrated the recruitment of a social self during self-face recognition in the social context. At least three brain networks for self-face-specific activation may be dissociated by different patterns of response-modulation in the social context, suggesting multiple dynamic self-other representations in the human brain.

The prevalence and clinical implications of pancreatic fat accumulation identified during a medical check-up.

ABSTRACT: Fatty pancreas (FP) is characterized by pancreatic fat accumulation and the subsequent development of pancreatic and metabolic complications. However, FP has not been categorized in the manual for abdominal ultrasound in cancer screening and health check-ups in Japan, and the pathology of FP has not been fully elucidated.Nine hundred and nineteen people who underwent a medical check-up had the severity of their pancreatic fat accumulation categorized after transabdominal ultrasonographic examination. The relationships between FP, lifestyle-related diseases, and fatty liver disease at this time were assessed using stratification analysis.The prevalence of FP was 46.8% (430/919). People with FP were more likely to be male and had higher prevalences of lifestyle-related diseases, including fatty liver disease. Men and women were similarly represented in each tertile of pancreas brightness. Older age; high waist circumference, triglyceride and glucose index, serum low-density lipoprotein-cholesterol, hepatic steatosis index; and low serum amylase were associated with the presence of severe FP. Moreover, the group with severe liver steatosis had a higher prevalence of FP and a higher pancreatic brightness score. Logistic regression analysis showed that individuals with liver steatosis were more likely to have severe FP.The severity of FP is associated with features of lifestyle-related diseases and the severity of liver steatosis. These findings suggest that high visceral fat content is associated with more severe fatty pancreas as a phenotype of ectopic fat accumulation, as well as fatty liver disease.

Learning second language vocabulary: neural dissociation of situation-based learning and text-based learning.

Second language (L2) acquisition necessitates learning and retrieving new words in different modes. In this study, we attempted to investigate the cortical representation of an L2 vocabulary acquired in different learning modes and in cross-modal transfer between learning and retrieval. Healthy participants learned new L2 words either by written translations (text-based learning) or in real-life situations (situation-based learning). Brain activity was then measured during subsequent retrieval of these words. The right supramarginal gyrus and left middle frontal gyrus were involved in situation-based learning and text-based learning, respectively, whereas the left inferior frontal gyrus was activated when learners used L2 knowledge in a mode different from the learning mode. Our findings indicate that the brain regions that mediate L2 memory differ according to how L2 words are learned and used.

The neural basis of agency: an fMRI study.

Agency, a feeling that the self is the cause of action, has a strong relationship to the processing of discrepancies between the predicted multi-sensory feedback from one's intended action and its actual outcome (hereafter, agency error). Although previous studies have explored the neural basis of agency by assessing the brain's response to agency error, the effects found are confounded by two types of error irrelevant to agency: a mismatch between different sensory inputs in general (sensory mismatch, SM error) and a basic response to any type of prediction error (oddball error). In this functional magnetic resonance imaging study, we identified the neural response specific to agency error by dissociating it from responses to SM and oddball errors. Subjects played a game in which they controlled an on-screen character. Neural responses to rare events of violated control and congruency between types of audio-visual feedback were compared to dissociate agency from SM error. In a separate session, subjects viewed repetitive motions of the character, and neural responses to rare events of unpredictable change in movement were identified as related to oddball error. Agency-error-specific activation was observed in the supplementary motor area (SMA), left cerebellum, right posterior parietal cortex (PPC), and right extrastriate body area (EBA). Oddball errors also activated areas near the PPC and EBA peaks. SM errors activated the pre-SMA and the right posterior superior temporal sulcus. Our results suggest that the SMA, cerebellum, and some parts of the PPC and EBA serve as the neural bases of agency.

Neural correlates of processing situational relationships between a part and the whole: an fMRI study.

Daily situations involve many objects and behaviors. To comprehend the meaning of situations, the relationships between objects, behaviors, and the situational context are important. To reveal the cortical networks involved in processing these relationships we used functional magnetic resonance imaging to compare brain activation during processing of behavior-situation and object-situation relationships. Each session examined two aspects of situational relationship processing: monitoring of the situational relationship and responses to irrelevant relationships. Monitoring was analyzed by comparing cortical activation during a situational relevance judgment task with that during a physical appropriateness judgment task. Responses were analyzed by comparing neural responses to situationally irrelevant and situationally relevant components. The left medial frontal cortex, fusiform gyrus, inferior frontal gyrus, calcarine sulcus, right anterior middle temporal gyrus, orbitoinsular junction, and occipito-temporo-parietal junction were commonly activated while monitoring relationships of both types. The right anterior middle temporal gyrus and orbitoinsular junction were considered to have roles in implicit monitoring because they were more deactivated during physical judgment tasks than during the resting state; this deactivation seemed to reflect unconscious situational monitoring in the resting state. Other regions seemed to be linked to explicit conscious monitoring. Responses to irrelevance were linked to separate and category-specific cortical activation in the left medial frontal cortex and frontal pole for behavioral irrelevance and in the left orbitofrontal cortex for irrelevant objects. We demonstrated that the hierarchical structure of processing situational relationships consisted of implicit monitoring, explicit monitoring, and category-specific responses to irrelevance.

Extraction of situational meaning by integrating multiple meanings in a complex environment: a functional MRI study.

Humans extract behaviorally significant meaning from a situation by integrating meanings from multiple components of a complex daily environment. To determine the neural underpinnings of this ability, the authors performed functional magnetic resonance imaging of healthy subjects while the latter viewed naturalistic scenes of two people and an object, including a threatening situation of a person being attacked by an offender with an object. The authors used a two-factorial design: the object was either aversive or nonaversive, and the offender's action was either directed to the person or elsewhere. This allowed the authors to examine the neural response to object aversiveness and person-directed intention separately. A task unrelated to threat was also used to address incidental (i.e., subconscious or unintentional) detection. Assuming individual differences in incidental threat detection, the authors used a functional connectivity analysis using principal components analysis of intersubject variability. The left lateral orbitofrontal cortex and medial prefrontal cortex (MPFC) were specifically activated in response to a threatening situation. The threat-related component of intersubject variability was extracted from these data and showed a significant correlation with personality scores. There was also a correlation between threat-related intersubject variability and activation for object aversiveness in the left temporal pole and lateral orbitofrontal cortex; person-directed intention in the left superior frontal gyrus; threatening situations in the left MPFC; and independently for both factors in the right MPFC. Results demonstrate independent processing of object aversiveness and person-directed intention in the left temporal-orbitofrontal and superior frontal networks, respectively, and their integration into situational meaning in the MPFC.

Identification of a New Theca/Interstitial Cell-Specific Gene and Its Biological Role in Growth of Mouse Ovarian Follicles at the Gonadotropin-Independent Stage.

Theca/interstitial cells are responsible for the growth and maturation of ovarian follicles. However, little is known about the theca/interstitial cell-specific genes and their functions. In this study, we explored transcriptomes of theca/interstitial cells by RNA-seq, and the novel biological roles of a theca cell marker, asporin (Aspn)/periodontal ligament-associated protein 1 (PLAP-1). RNA-seq detected 432 and 62 genes expressed specifically in theca/interstitial cells and granulosa cells isolated from 3-weeks old mouse ovaries. Gene ontology analysis demonstrated that these genes were largely categorized into four major groups: extracellular matrix organization-related terms, chemotaxis-related terms, the angiogenesis-related terms, and morphogenesis-related terms. In situ hybridization demonstrated that the newly detected representative gene, Aspn/PLAP-1, was detected specifically in the outer layer of theca cells in contrast with the expression of the basal lamina-specific gene, Nidgen-1. Intriguingly, an Aspn/PLAP-1 antibody completely arrested the growth of secondary follicles that is the gonadotropin-independent follicle developmental stage. Furthermore, transforming growth factor-ß (TGF-ß)-triggered signaling was induced by the Aspn/PLAP-1 antibody treatment, which is consistent with the inhibitory effect of Aspn/PLAP-1 on TGF-ß. Altogether, these results suggest that theca cells are classified into subpopulations on the basis of new marker genes and their biological functions, and provide evidence that Aspn/PLAP-1 is expressed exclusively in the outer layer of theca cells and plays a pivotal role in the growth of secondary follicles via downregulation of the canonical TGF-ß signaling cascade.

Face-specific and domain-general characteristics of cortical responses during self-recognition.

The ability of visual self-recognition in animals and infants is considered a hallmark of the domain-general cognitive representation of the self, which also underpins higher social ability. Cortical regions activated during self-face recognition in human adults have been accordingly expected to play the domain-general role in self-processing. However, there is no evidence of the involvement of this network in non-face domains. We compared cortical responses during face and name recognition of self, a friend, and an unfamiliar person, using functional magnetic resonance imaging (fMRI). Recognition of the self-face activated the right inferior frontal, precentral, supramarginal, and bilateral ventral occipitotemporal regions, consistent with previous findings, whereas these regions did not show self-specific activation during name recognition. During both face and name recognitions, increased activation for the friend and unfamiliar person than for the self was observed in the bilateral temporoparietal regions, and higher activation for the self and friend than for the unfamiliar person was observed in the medial cortical structures. These results suggest that the role of the self-specific networks during face recognition is not domain-general, but rather face-specific, and that the medial cortical structures, which are also implicated in self-referential processes, are not relevant to self-other distinction during face or name recognition. Instead, the reduced temporoparietal activation is a domain-general characteristic of the cortical response during self-recognition, which may reflect suppression of an automatic preparatory process for social interaction, possibly paralleling the disappearance of social behavior to the mirrored self-image at the emergence of self-recognition in animals and infants.

Is Broca's area involved in the processing of passive sentences? An event-related fMRI study.

We used functional magnetic resonance imaging (fMRI) to investigate whether activation in Broca's area is greater during the processing of passive versus active sentences in the brains of healthy subjects. Twenty Japanese native speakers performed a visual sentence comprehension task in which they were asked to read a visually presented sentence and to identify the agent or the patient in the sentence by pressing a button. We found that the processing of passive sentences elicited no greater activation than that of active sentences in Broca's area. However, passive sentences elicited greater activation than active sentences in the left frontal operculum and the inferior parietal lobule. Thus, our neuroimaging results suggest that deficits in the comprehension of passive sentences in Japanese aphasics are induced not by lesions to Broca's area, but to the left frontal operculum and/or the inferior parietal lobule.

Brain activation during the course of sentence comprehension.

The purpose of this study is to determine, by functional magnetic resonance imaging, how the activated regions of the brain change as a Japanese sentence is presented in a grammatically correct order. In this study, we presented constituents of a sentence to Japanese participants one by one at regular intervals. The results showed that the left lingual gyrus was significantly activated at the beginning of the sentence, then the left inferior frontal gyrus and left supplementary motor area, in the middle of the sentence, and the left inferior temporal gyrus, at the end of the sentence. We suggest that these brain areas are involved in sentence comprehension in this temporal order.

Adaptive ability to cope with atypical or novel situations involving tool use: an fMRI approach.

We investigated the neural mechanisms underlying the ability to cope in atypical or novel situations using tools. We hypothesized that two cognitive components support this ability: adaptive coordination (for adapting to situational demands) and cognitive inhibition (for inhibiting the incongruent actions afforded by tools). We had subjects choose novel tools for a given task or choose among familiar tools in an atypical situation, during which we examined cortical activation in their brains using functional magnetic resonance imaging. Neural activation during adaptive coordination was observed in the left lateral orbitofrontal cortex, inferior frontal gyrus and sulcus, middle and medial frontal gyrus, intraparietal sulcus, precentral sulcus, inferior temporal gyrus, supramarginal gyrus, the bilateral insula, anterior cingulate cortex, and the right callosal sulcus. Activation indicating cognitive inhibition was observed in the right middle and inferior frontal gyrus. These findings demonstrate that the left parietal region shapes basic action, whereas the right frontal region inhibits stereotypical action. The left frontal regions are thought to be linked to the processing of ambiguous actions and play key roles in coordinating actions, whereas other regions are involved in processing situational contexts. Our results may be important for understanding the neural systems underlying adaptability to daily social situations.

Neural bases of human mate choice: multiple value dimensions, sex difference, and self-assessment system.

Mate choice is an example of sophisticated daily decision making supported by multiple componential processes. In mate-choice literature, different characteristics of the value dimensions, including the sex difference in the value dimensions, and the involvement of self-assessment due to the mutual nature of the choice, have been suggested. We examined whether the brain-activation pattern during virtual mate choice would be congruent with these characteristics in terms of stimulus selectivity and activated brain regions. In measuring brain activity, young men and women were shown two pictures of either faces or behaviors, and they indicated which person they would choose either as a spouse or as a friend. Activation selective to spouse choice was observed face-selectively in men's amygdala and behavior-selectively in women's motor system. During both partner-choice conditions, behavior-selective activation was observed in the temporoparietal regions. Taking the available knowledge of these regions into account, these results are congruent with the suggested characteristics of value dimensions for physical attractiveness, parenting resources, and beneficial personality traits for a long-lasting relationship, respectively. The medial prefrontal and posterior cingulate cortices were nonselectively activated during the partner choices, suggesting the involvement of a self-assessment process. The results thus provide neuroscientific support for the multi-component mate-choice mechanism.

Right frontopolar cortex activity correlates with reliability of retrospective rating of confidence in short-term recognition memory performance.

Human memory systems contain self-monitoring mechanisms for evaluating their progress. People can change their learning strategy on the basis of confidence in their performance at that time. However, it has not been fully understood how the brain is engaged in reliable rating of confidence in past recognition memory performance. We measured the brain activity by fMRI while healthy subjects performed a visual short-term recognition memory test and then rated their confidence in their answers as high, middle, or low. As shown previously, their behavioral performance in the confidence rating widely varied; some showed a positive confidence-recognition correlation (i.e., "rate reliably") while others did not. Among brain regions showing greater activity during rating their confidence relative to during a control, non-metamemory task (discriminating brightness of words), only a posterior-dorsal part of the right frontopolar cortex exhibited higher activity as the confidence level better correlated with actual recognition memory performance. These results suggest that activation in the right frontopolar cortex is key to a reliable, retrospective rating of confidence in short-term recognition memory performance.

Effect of motion smoothness on brain activity while observing a dance: An fMRI study using a humanoid robot.

Motion smoothness is critical in transmitting implicit information of body action, such as aesthetic qualities in dance performances. We expected that the perception of motion smoothness would be characterized by great intersubject variability deriving from differences in personal backgrounds and attitudes toward expressive body actions. We used functional magnetic resonance imaging and a humanoid robot to investigate the effects of the motion smoothness of expressive body actions and the intersubject variability due to personal attitudes on perceptions during dance observation. The effect of motion smoothness was analyzed by both conventional subtraction analysis and functional connectivity analyses that detect cortical networks reflecting intersubject variability. The results showed that the cortical networks of motion- and body-sensitive visual areas showed increases in activity in areas corresponding with motion smoothness, but the intersubject variability of personal attitudes toward art did not influence these active areas. In contrast, activation of cortical networks, including the parieto-frontal network, has large intersubject variability, and this variability is associated with personal attitudes about the consciousness of art. Thus, our results suggest that activity in the cortical network involved in understanding action is influenced by personal attitudes about the consciousness of art during observations of expressive body actions.

Neural basis of sentence processing in which incoming words form a sentence.

This study examined the neural basis underlying the sequential involvement of sentence processing and determined the point at which the processing cost for an object-initial sentence was observed. We presented each phrase in a Japanese object-initial sentence to Japanese participants one by one using an event-related functional MRI technique and compared with our previous subject-initial experiment. We found that the left lingual gyrus was activated upon presentation of the first noun phrases, and the left inferior frontal gyrus upon presentation of the second noun phrases. The processing cost for an object-initial sentence was observed during verb recognition. Our results suggest that the syntactic complexity of an object-initial sentence is processed by the human brain upon verb recognition.

Neural activity in the human brain signals logical rule identification.

To select an appropriate action, we conform to a behavioral rule determined uniquely in each behavioral context. If the rule is not predetermined and must be discovered, we often test hypotheses concerning rules by applying one candidate rule after another. The neural mechanisms underlying such rule identification are still unknown. To explore which brain areas are involved in the process of logical rule identification and to determine whether such areas differ from those taking part in implementing the rule to find a suitable action, we measured brain activation using functional magnetic resonance imaging while subjects performed a rule-identification task. The subjects were required to select a red or blue square on a screen based on either a "sequence rule" or a "probability rule." Positive or negative feedback to the subject's choice led the subject to identify the correct rule. We found that the posterior medial frontal cortex (pMFC), caudate nucleus, fusiform gyrus, and middle temporal cortex exhibited significant activation during the period when subjects underwent the hypothesis testing. Among these brain areas, the pMFC and caudate nucleus were also activated in response to the critical feedback signals selectively during the trials when the subjects identified a rule. Furthermore, we found a significant enhancement in effective connectivity between the active regions in the pMFC and caudate regions.

Decrease in glucose metabolism in frontal cortex associated with deterioration of microstructure of corpus callosum measured by diffusion tensor imaging in healthy elderly.

The neural functions of signaling are carried out by the interconnection of neurons via neuronal fibers. Diffusion tensor imaging has recently become an established technique that enables the in vivo visualization of white matter (WM) fibers. Studies of normal aging have suggested the disruption of WM fiber microstructures with anterior-posterior gradient. Because neuronal activity is tightly coupled with glucose metabolism, neuronal death or a decrease in synaptic activity with aging may cause a decrease in glucose metabolism in the brain. We examined whether the disruption of callosal fiber microstructures in the healthy elderly is accompanied by changes in regional glucose metabolism (rMGlu) in the brain. Fifteen healthy volunteers in their seventies participated. Fractional anisotropies (FAs) of the genu and splenium of the corpus callosum (CC) were measured for each subject, and their correlations with rMGlu were analyzed using SPM2 software. We found a statistically significant positive correlation of rMGlu in the bilateral frontal cortices with the FA of the genu of the CC, whereas there was no correlation of the FA of the splenium of the CC and rMGlu. By voxel-based morphometry, we found no decrease in gray matter concentration associated with FA. The results indicate that neuronal activity in the frontal cortices may decrease with the disruption of the microstructures of the CC without corresponding gray matter atrophy.

Cortical mechanism of communicative speech production.

Communicative speech requires conformity not only to linguistic rules but also to behavior that is appropriate for social interaction. The existence of a special brain mechanism for such behavioral aspects of communicative speech has been suggested by studies of social impairment in autism, and it may be related to communicative vocalization in animals. We used functional magnetic resonance imaging (fMRI) to measure cortical activation while normal subjects casually talked to an actor (communication task) or verbally described a situation (description task) while observing video clips of an action performed by a familiar or an unfamiliar actor in a typical daily situation. We assumed that the communication task differed from the description task in the involvement of behavioral aspects of communicative speech production, which may involve the processing of interaction-relevant biographical information. Significantly higher activation was observed during the communication task than during the description task in the medial prefrontal cortex (polar and dorsal parts), the bilateral anterior superior temporal sulci, and the left temporoparietal junction. The results suggest that these regions play a role in the behavioral aspects of communicative speech production, presumably in understanding of the context of the social interaction. The activation of the polar part of the medial prefrontal cortex during the communication task was greater when the actor was familiar than when the actor was unfamiliar, suggesting that this region is involved in communicative speech production with reference to biological information. The precuneus was activated during the communication task only with the familiar actor, suggesting that this region is related to access to biographical information per se.

Comprehension of implicit meanings in social situations involving irony: a functional MRI study.

To understand implicit social meanings, the interaction of literal meanings and relevant information in a situational context is important. However, previous studies have not investigated such contextual interactions. Using functional magnetic resonance imaging (fMRI), we investigated cortical mechanisms underlying the processing of implicit meanings, particularly irony, in realistic social situations, focusing on contextual interactions. Healthy subjects were shown pictures depicting daily communicative situations during judgment tasks involving situational appropriateness and literal correctness. The left medial prefrontal cortex showed significantly greater activation during tasks involving situational judgments than during literal judgments. The right temporal pole was activated task-independently during irony-specific processing. The medial orbitofrontal cortex was activated task-dependently during irony processing in situational judgment tasks. These regions have been reported to be involved in theory of mind, and have not been implicated in previous studies on the linguistic processing of implicit meanings. This suggests that the intentional assessment of situational appropriateness for task execution is carried out in the left medial prefrontal cortex, whereas irony is processed in the right temporal pole by assessing situational context automatically, and is judged based on the situational context in the medial orbitofrontal cortex. Our results show that the processing of implicit meanings and irony in contextually rich situations depends on brain mechanisms involved in the "theory of mind," based on processing relevant information in a situational context, and suggest different functions in each region.