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This study aimed to investigate alterations in white matter (WM) microstructure in patients with psychotic and non-psychotic bipolar disorder (PBD and NPBD, respectively). We used 3T-magnetic resonance imaging to examine 29 PBD, 23 NPBD, and 65 healthy control (HC) subjects. Using tract-based spatial statistics for diffusion tensor imaging data, we compared fractional anisotropy (FA) and mean diffusion (MD) pairwise among the PBD, NPBD, and HC groups. We found several WM areas of decreased FA or increased MD in the PBD and NPBD groups compared to HC. PBD showed widespread FA decreases in the corpus callosum as well as the bilateral internal capsule and fornix. However, NPBD showed local FA decreases in a part of the corpus callosum body as well as in limited regions within the left cerebral hemisphere, including the anterior and posterior corona radiata and the cingulum. In addition, both PBD and NPBD shared widespread MD increases across the posterior corona radiata, cingulum, and sagittal stratum. These findings suggest that widespread WM microstructural alterations might be a common neuroanatomical characteristic of bipolar disorder, regardless of being psychotic or non-psychotic. Particularly, PBD might involve extensive inter-and intra-hemispheric WM connectivity disruptions. [ABSTRACT FROM AUTHOR]

Insomnia is prevalent among dialysis patients and affects their mortality. Although cognitive behavioral therapy for insomnia (CBTi) is recommended, attending regular face-to-face CBTi sessions is a major challenge for patients. We evaluated the effectiveness of a self-directed computerized CBTi (cCBTi) in dialysis patients, and investigated changes in resting-state brain connectivity and inflammatory cytokines following cCBTi. Thirty-five patients undergoing maintenance hemodialysis or peritoneal dialysis who had insomnia were screened for participation in the study, with 17 participants included in the final analyses. A self-directed cCBTi protocol accessed via tablet computer during dialysis or at home was developed and applied. Information about sleep, anxiety, depression, laboratory data, and resting-state functional magnetic resonance imaging data was obtained 3–5 days before and after cCBTi. cCBTi improved sleep quality, and this was correlated with increased resting-state brain connectivity between the default-mode network and the premotor/dorsolateral prefrontal cortex. The decrement of interleukin-1β levels were correlated with improved sleep quality and increased brain connectivity after cCBTi. Our pilot study findings suggest that cCBTi is effective for dialysis patients with insomnia, and the therapeutic effects of cCBTi are related to changes in brain functional connectivity and inflammatory cytokines. • Computerized CBT for insomnia (cCBTi) improved sleep quality in dialysis patients. • Changes in brain connectivity after cCBTi correlated with improved sleep. • Decrease in IL-1β correlated with improved sleep and increased brain connectivity. [ABSTRACT FROM AUTHOR]

This study aimed to investigate abnormalities in the gray matter and white matter (GM and WM, respectively) that are shared between schizophrenia (SZ) and bipolar disorder (BD). We used 3T-magnetic resonance imaging to examine patients with SZ, BD, or healthy control (HC) subjects (aged 20–50 years, N = 65 in each group). We generated modulated GM maps through voxel-based morphometry (VBM) for T1-weighted images and skeletonized fractional anisotropy, mean diffusion, and radial diffusivity maps through tract-based special statistics (TBSS) methods for diffusion tensor imaging (DTI) data. These data were analyzed using a generalized linear model with pairwise comparisons between groups with a family-wise error corrected P < 0.017. The VBM analysis revealed widespread decreases in GM volume in SZ compared to HC, but patients with BD showed GM volume deficits limited to the right thalamus and left insular lobe. The TBSS analysis showed alterations of DTI parameters in widespread WM tracts both in SZ and BD patients compared to HC. The two disorders had WM alterations in the corpus callosum, superior longitudinal fasciculus, internal capsule, external capsule, posterior thalamic radiation, and fornix. However, we observed no differences in GM volume or WM integrity between SZ and BD. The study results suggest that GM volume deficits in the thalamus and insular lobe along with widespread disruptions of WM integrity might be the common neural mechanisms underlying the pathologies of SZ and BD. [ABSTRACT FROM AUTHOR]

How the brain supports normal episodic memory function without medial temporal lobe (MTL) structures has not been well characterized, which could provide clues for new therapeutic targets for people with MTL dysfunction‐related memory impairment. To characterize brain network supporting effective episodic memory function in the absence of unilateral MTL, we investigated the whole‐brain cortical interactions during functional magnetic resonance imaging memory encoding paradigms of words and figures in patients who showed a normal range of memory capacity following unilateral MTL resection and healthy controls (HC). Compared to the HC, the patients showed less activation in the left inferior frontal areas and right thalamus together with greater activation in the many cortical areas including the medial prefrontal cortex (mPFC). Task‐based functional connectivity (FC) analysis revealed that the mPFC showed stronger interactions with widespread brain areas in both patient groups, including the hippocampus contralateral to the resection. Moreover, the strength of the mPFC FC predicts the individual memory capacity of the patients. Our data suggest that hyperconnectivity of distributed brain areas, especially the mPFC, is a neural mechanism for memory function in the absence of one MTL. [ABSTRACT FROM AUTHOR]

Objectives. Anhedonia in schizophrenia results from a deficit in anticipatory pleasure rather than consummatory pleasure. This study aimed to determine the neural basis of the predictive and experiential components of anticipatory pleasure in schizophrenia. Methods. A hedonic rating task was performed by 15 patients with schizophrenia and 17 controls while undergoing functional magnetic resonance imaging. Participants evaluated the level of pleasantness for the preview/predictive phase, comprising a narration and adjunctive audiovisual stimuli for pleasurable experience, and the subsequent viewing/experiential phase, comprising a video clip for a pleasant event. Results. A significant group-by-phase interaction was seen in the rostral anterior cingulate cortex (ACC) and caudate, resulting from reduced activations in patients during the preview phase. Patients showed significantly reduced activation in the frontopolar cortex and rostral ACC during the preview phase. The signal changes in the caudate and frontopolar cortex were associated with increase in hedonic response during the sequential pleasure experiences. Conclusions. Augmentation of hedonic enjoyment between the predictive and experiential stages of anticipatory pleasure is reduced in schizophrenia because of diminished activity in the reward-related regions during the prediction of pleasure. During cued-emotional experiences of anticipatory pleasure, patients seem to have difficulties in the integration of emotional information. [ABSTRACT FROM AUTHOR]

Patients with schizophrenia often show abnormal social interactions, which may explain their social exclusion behaviors. This study aimed to elucidate patients’ brain responses to social rejection in an interactive situation. Fifteen patients with schizophrenia and 16 healthy controls participated in the functional magnetic resonance imaging experiment with the virtual handshake task, in which socially interacting contents such as acceptance and refusal of handshaking were implemented. Responses to the refusal versus acceptance conditions were evaluated and compared between the two groups. Controls revealed higher activity in the refusal condition compared to the acceptance condition in the right superior temporal sulcus, whereas patients showed higher activity in the prefrontal regions, including the frontopolar cortex. In patients, contrast activities of the right superior temporal sulcus were inversely correlated with the severity of schizophrenic symptoms, whereas contrast activities of the left frontopolar cortex were positively correlated with the current anxiety scores. The superior temporal sulcus hypoactivity and frontopolar hyperactivity of patients with schizophrenia in social rejection situations may suggest the presence of mentalizing deficits in negative social situations and inefficient processes of socially aberrant stimuli, respectively. These abnormalities may be one of the neural bases of distorted or paranoid beliefs in schizophrenia. [ABSTRACT FROM AUTHOR]

Aim Attention deficit has been reported in both schizophrenia patients and patients with major depressive disorder (MDD). The aim of this study was to elucidate the deficits in sustained attention and associated neural network dysfunctions in schizophrenia patients and MDD patients, and to investigate the difference between the two patient groups. Methods Twelve schizophrenia patients, 12 patients with non-psychotic MDD, and 12 healthy control subjects participated in this study. A sustained attention to response task ( SART) was used to measure attention capacity. Cerebral blood flow ( CBF) during attention tasks was measured using H215O positron emission tomography. Statistical parametric mapping and analysis of covariance were performed to compare the behavioral performance and CBF changes during SART among three groups. Results Behavioral performances were not significantly different among the three groups except for an increased commission error rate in the schizophrenia group. Regional CBF during SART was significantly reduced in the left inferior frontal gyrus, the left cuneus, and the right superior parietal lobule and increased in the right superior frontal gyrus and the right cuneus in the schizophrenia group compared to the healthy control group. In the MDD group, neither significant regional CBF difference nor behavioral deficit was found compared to the healthy control group. Conclusion Behavioral performance deficit and perfusion changes in the prefrontal and parietal cortices during SART were observed only in the schizophrenia group. Prefrontal and parietal network dysfunction for sustained attention may be involved in the pathophysiology of schizophrenia. [ABSTRACT FROM AUTHOR]

Abstract: The anterior insula has been proposed to play a crucial role in eating disorders. However, it is still poorly understood how the anterior insula is involved in anorexia nervosa (AN) and bulimia nervosa (BN), which are characterized by opposite motivational responses to food. We applied a cue-reactivity paradigm using blood oxygen level-dependent functional magnetic resonance imaging in women with AN (N =18) and BN (N =20) and age-matched healthy controls (N =20). We defined the left anterior insula as a region-of-interest and performed seed-based functional connectivity and effective connectivity MRI analysis. In response to food images compared to non-food images, both the AN group and BN group demonstrated increased activity in the left anterior insula. In the AN group, the left anterior insula demonstrated significant interactions with the right insula and right inferior frontal gyrus. In the BN group, the left anterior insula demonstrated significant interactions with the medial orbitofrontal cortex. The distinct patterns of functional and effective connectivity of the anterior insula may contribute to the different clinical features of AN and BN. [Copyright &y& Elsevier]

Abstract: Resting-state functional MRI (fMRI) is now providing further understanding of neuropsychiatric illnesses. However, its practical applicability in the clinical realms is still questionable. Here we report three consecutive followed-up resting-state fMRI data in a single case with Wernicke encephalopathy before and after high-dose thiamine replacement therapy ranging over 20 months. We measured the mammillothalamic functional connectivity strength between the first ROI (mammillary body) and a voxel which showed the highest co-activation among voxels within the anterior thalamus (the second ROI) to enhance the specificity of the functional connectivity data. We found that the time-series changes in the mammillothalamic functional connectivity generally paralleled to the changes in delayed verbal and nonverbal recall memory scores in the left and right hemisphere, respectively. Among these, the left-side connectivity and delayed verbal recall score seemed to be related to the overall clinical status change. Modified directed transfer function (dDTF) analysis also identified significant information flows with mammillary-to-thalamic direction except at the acute illness state. Our findings, though preliminary in nature, suggest the practical applicability of resting-state fMRI to trace an effect of thiamine replacement therapy on the memory tract function in Wernicke encephalopathy at single-patient level. [Copyright &y& Elsevier]

This study examined the relationship between loneliness levels and daily patterns of mobile keystroke dynamics in healthy individuals. Sixty-six young healthy Koreans participated in the experiment. Over five weeks, the participants used a custom Android keyboard. We divided the participants into four groups based on their level of loneliness ( no loneliness , moderate loneliness , severe loneliness , and very severe loneliness ). The very severe loneliness group demonstrated significantly higher typing counts during sleep time than the other three groups (one-way ANOVA, F = 3.75, p < 0.05). In addition, the average cosine similarity value of weekday and weekend typing patterns in the very severe loneliness group was higher than that in the no loneliness group (Welch's t -test, t = 2.27, p < 0.05). This meant that the no loneliness group's weekday and weekend typing patterns varied, whereas the very severe loneliness group's weekday and weekend typing patterns did not. Our results indicated that individuals with very high levels of loneliness tended to use mobile keyboards during late-night hours and did not significantly change their smartphone usage behavior between weekdays and weekends. These findings suggest that mobile keystroke dynamics have the potential to be used for the early detection of loneliness and the development of targeted interventions., Competing Interests: Competing interestsThe authors have no relevant financial or non-financial interests to disclose., (© The Author(s) 2023.)

Objective: : This study used network analyses to examine network structures reflecting interactions between specific domains of social functioning in schizophrenia (SZ) and bipolar disorder (BD)., Methods: We used the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) to assess six domains of social functioning ('cognition', 'mobility', 'self-care', 'getting along', 'life activities', and 'participation') in 143 patients with SZ, 81 patients with BD, and 106 healthy subjects. We constructed regularized partial correlation networks, estimated network centrality and edge strength, tested network stability, and compared SZ and BD network structures., Results: Patients with SZ showed a significantly higher level of functional disability than patients with BD. In the networks we constructed, 'cognition' was the most central domain of social functioning in both SZ and BD. The 'cognition' domain was primarily associated with the 'getting along' domain in the SZ network and the 'life activities' domain in the BD network. We found no significant group-level differences in network structures for SZ vs. BD., Conclusion: Our results suggest that cognition may play a pivotal role in social functioning in both SZ and BD. In addition, domains of social functioning in SZ and BD have similar network structures despite the higher level of disability in SZ compared to BD.

Objective: More recently, attention has turned to the linkage between childhood trauma and emotional dysregulation, but the evidence in bipolar disorder (BD) is limited. To determine neurobiological relationships between childhood trauma, current anxiety, and impulsivity, we investigated cortical volumetric correlates of these clinical factors in BD., Methods: We studied 36 patients with DSM-5 BD and 29 healthy controls. Childhood trauma, coexisting anxiety, and impulsivity were evaluated with the Korean version-Childhood Trauma Questionnaire (CTQ), the Korean version-Beck Anxiety Inventory (BAI), and the Korean version-Barratt Impulsiveness Scale (BIS). Voxel-based morphometry (VBM) was used to assess gray matter volume (GMV) alterations on the brain magnetic resonance imaging (MRI). Partial correlation analyses were conducted to examine associations between the GMV and each scale in the BD group., Results: Childhood trauma, anxiety, and impulsivity were interrelated in BD. BD patients revealed significant inverse correlations between the GMV in the right precentral gyrus and CTQ scores (r=-0.609, p<0.0003); between the GMV in the left middle frontal gyrus and BAI scores (r=-0.363, p=0.044). Moreover, patients showed similar tendency of negative correlations between the GMV in the right precentral gyrus and BIS scores; between the GMV in the left middle frontal gyrus and CTQ scores., Conclusion: The present study provides evidence for a neural basis between childhood trauma and affect regulations in BD. The GMV alterations in multiple frontal lobe areas may represent neurobiological markers for anticipating the course of BD.

Objective: We aimed to develop predictive models to identify suicide attempters among individuals with suicide ideation using a machine learning algorithm., Methods: Among 35,116 individuals aged over 19 years from the Korea National Health & Nutrition Examination Survey, we selected 5,773 subjects who reported experiencing suicide ideation and had answered a survey question about suicide attempts. Then, we performed resampling with the Synthetic Minority Over-sampling TEchnique (SMOTE) to obtain data corresponding to 1,324 suicide attempters and 1,330 non-suicide attempters. We randomly assigned the samples to a training set (n=1,858) and a test set (n=796). In the training set, random forest models were trained with features selected through recursive feature elimination with 10-fold cross validation. Subsequently, the fitted model was used to predict suicide attempters in the test set., Results: In the test set, the prediction model achieved very good performance [area under receiver operating characteristic curve (AUC)=0.947] with an accuracy of 88.9%., Conclusion: Our results suggest that a machine learning approach can enable the prediction of individuals at high risk of suicide through the integrated analysis of various suicide risk factors.

This study investigated whether resting-state functional connectivity is associated with long-term clinical outcomes of patients with schizophrenia. Resting-state brain images were obtained from 79 outpatients with schizophrenia and 30 healthy controls (HC), using a 3 T-MRI scanner. All patients were 20-50 years old with >3 years' duration of illness and appeared clinically stable. We assessed their psychopathology using the 18-item Brief Psychiatric Rating Scale (BPRS-18) and divided them into "good," "moderate," and "poor" outcome (SZ-GO, SZ-MO, and SZ-PO) groups depending on BPRS-18 total score. We obtained individual functional connectivity maps between a seed region of the bilateral posterior cingulate cortex (PCC) and all other brain regions and compared the functional connectivity of the default mode network (DMN) among the HC and 3 schizophrenia outcome groups, with a voxel-wise threshold of P < .001 within a cluster-extent threshold of 114 voxels. Additionally, we assessed correlations between functional connectivity and BPRS-18 scores. The SZ-MO and SZ-PO groups showed decreased functional connectivity between PCC and right ventromedial prefrontal cortex (vmPFC), left middle cingulate cortex, and left frontopolar cortex (FPC) compared to the SZ-GO and HC groups. DMN connectivity in the right vmPFC and left FPC negatively correlated with subscale scores of the BPRS-18, except the negative symptoms subscale. In this study, poorer clinical outcomes in patients with schizophrenia were associated with decreased DMN connectivity. In particular, the decreased functional connectivity might be related to the severity of positive and mood symptoms rather than negative symptoms., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: In this study, we aimed to develop a model predicting individuals with suicide ideation within a general population using a machine learning algorithm., Methods: Among 35,116 individuals aged over 19 years from the Korea National Health & Nutrition Examination Survey, we selected 11,628 individuals via random down-sampling. This included 5,814 suicide ideators and the same number of non-suicide ideators. We randomly assigned the subjects to a training set (n=10,466) and a test set (n=1,162). In the training set, a random forest model was trained with 15 features selected with recursive feature elimination via 10-fold cross validation. Subsequently, the fitted model was used to predict suicide ideators in the test set and among the total of 35,116 subjects. All analyses were conducted in R., Results: The prediction model achieved a good performance [area under receiver operating characteristic curve (AUC)=0.85] in the test set and predicted suicide ideators among the total samples with an accuracy of 0.821, sensitivity of 0.836, and specificity of 0.807., Conclusion: This study shows the possibility that a machine learning approach can enable screening for suicide risk in the general population. Further work is warranted to increase the accuracy of prediction.

Objective: How the brain supports intermediate-term preservation of memory in patients who have undergone unilateral medial temporal lobe resection (MTLR) has not yet been demonstrated. To understand the neural basis of episodic memory in the intermediate term after surgery for temporal lobe epilepsy (TLE), the authors investigated the relationship between the activation of the hippocampus (HIP) during successful memory encoding and individual memory capacity in patients who had undergone MTLR. They also compared hippocampal activation with other parameters, including structural volumes of the HIP, duration of illness, and age at seizure onset., Methods: Thirty-five adult patients who had undergone unilateral MTLR at least 1 year before recruiting and who had a favorable seizure outcome were enrolled (17 left MTLR, 18 right MTLR; mean follow-up 6.31 ± 2.72 years). All patients underwent a standardized neuropsychological examination of memory function and functional MRI scanning with a memory-encoding paradigm of words and figures. Activations of the HIP during successful memory encoding were calculated and compared with standard neuropsychological memory scores, hippocampal volumes, and other clinical variables., Results: Greater activation in the HIP contralateral to the side of the resection was related to higher postoperative memory scores and greater postoperative memory improvement than the preoperative baseline in both patient groups. Specifically, postoperative verbal memory performance was positively correlated with contralateral right hippocampal activation during word encoding in the left-sided surgery group. In contrast, postoperative visual memory performance was positively correlated with contralateral left hippocampal activation during figure encoding in the right-sided surgery group. Activation of the ipsilateral remnant HIP was not correlated with any memory scores or volumes of the HIP; however, it had a negative correlation with the seizure-onset age and positive correlation with the duration of illness in both patient groups., Conclusions: For the first time, a neural basis that supports effective intermediate-term episodic memory after unilateral MTLR has been characterized. The results provide evidence that engagement of the HIP contralateral rather than ipsilateral to the side of resection is responsible for effective memory function in the intermediate term (> 1 year) after surgery in patients who have undergone left MTLR and right MTLR. Engagement of the material-specific contralesional HIP, verbal memory in the left-sided surgery group, and visual memory in the right-sided surgery group were observed.

Innovative sound absorbers, the design of which is based on carbon nanotubes and graphene derivatives, could be used to make more efficient sound absorbing materials because of their excellent intrinsic mechanical and chemical properties. However, controlling the directional alignments of low-dimensional carbon nanomaterials, such as restacking, alignment, and dispersion, has been a challenging problem when developing sound absorbing forms. Herein, we present the directionally antagonistic graphene oxide-polyurethane hybrid aerogel we developed as a sound absorber, the physical properties of which differ according to the alignment of the microscopic graphene oxide sheets. This porous graphene sound absorber has a microporous hierarchical cellular structure with adjustable stiffness and improved sound absorption performance, thereby overcoming the restrictions of both geometric and function-orientated functions. Furthermore, by controlling the inner cell size and aligned structure of graphene oxide layers in this study, we achieved remarkable improvement of the sound absorption performance at low frequency. This improvement is attributed to multiple scattering of incident and reflection waves on the aligned porous surfaces, and air-viscous resistance damping inside interconnected structures between the urethane foam and the graphene oxide network. Two anisotropic sound absorbers based on the directionally antagonistic graphene oxide-polyurethane hybrid aerogels were fabricated. They show remarkable differences owing to the opposite alignment of graphene oxide layers inside the polyurethane foam and are expected to be appropriate for the engineering design of sound absorbers in consideration of the wave direction.

Humans can easily detect vibrotactile stimuli up to several hundred hertz, but underlying large-scale neuronal processing mechanisms in the cortex are largely unknown. Here, we investigated the macroscopic neural correlates of various vibrotactile stimuli including artificial and naturalistic ones in human primary and secondary somatosensory cortices (S1 and S2, respectively) using electrocorticography (ECoG). We found that tactile frequency-specific high-gamma (HG, 50-140 Hz) activities are seen in both S1 and S2 with different temporal dynamics during vibration (>100 Hz). Stimulus-evoked S1 HG power, which exhibited short-delayed peaks (50-100 ms), was attenuated more quickly in vibration than in flutter (<50 Hz), and their attenuation patterns were frequency-specific within vibration range. In contrast, S2 HG power, which was activated much later than that of S1 (150-250 ms), strikingly increased with increasing stimulus frequencies in vibration range, and their changes were much greater than those in S1. Furthermore, these S1-S2 HG patterns were preserved in naturalistic stimuli such as coarse/fine textures. Our results provide persuasive evidence that S2 is critically involved in neural processing for high-frequency vibrotaction. Therefore, we propose that S1-S2 neuronal co-operation is crucial for full-range, complex vibrotactile perception in human.

Objective: The aim of this randomized, sham-controlled study was to investigate the therapeutic effects of underlying neurobiological changes after 2-week repetitive transcranial magnetic stimulation (rTMS) treatment using functional connectivity magnetic resonance imaging in patients with major depression., Methods: Twenty-four patients with major depressive disorder diagnosed with DSM-IV-TR criteria were randomly assigned to the active rTMS (n = 13) or sham (n = 11) groups from January 2009 to June 2011. rTMS was given for 2 weeks at 110% of the motor threshold for 10 minutes at 10 Hz over the left dorsolateral prefrontal cortex (DLPFC). Resting state functional connectivity was evaluated before and after rTMS. The 17-item Hamilton Depression Rating Scale (HDRS) was administered, and neurocognitive tasks were performed. We examined between-group differences in functional connectivity changes from the bilateral DLPFC., Results: Participants in the active rTMS group showed significant clinical improvement in HDRS scores compared to those in the sham group (P < .001). After 2-week rTMS, there were significant differences in changes in DLPFC-left caudate connectivity (corrected P < .05): the active group showed a greater reduction of connectivity strength between the DLPFC and left caudate compared to the sham group. Reduced levels of DLPFC-left caudate connectivity predicted improvement in depressive symptoms (r = 0.58, P = .001). Additionally, a positive correlation between residual depressive symptoms and connectivity strength after 2-week rTMS was found (r = 0.46, P = .023)., Conclusions: High-frequency rTMS over the left DLPFC showed therapeutic effects in patients with major depression. The therapeutic effect of rTMS is related to the modulation of functional connectivity in the frontostriatal network., Trial Registration: ClinicalTrials.gov identifier: NCT01325831​., (© Copyright 2016 Physicians Postgraduate Press, Inc.)

Sustained attention is an essential brain function that enables a subject to maintain attention level over the time of a task. In previous work, the right inferior parietal lobe (IPL) has been reported as one of the main brain regions related to sustained attention, however, the right lateralization of vigilance/sustained attention is unclear because information about the network for sustained attention is traditionally provided by neglect patients who typically have right brain damage. Here, we investigated sustained attention by applying a virtual lesion technique, transcranial magnetic stimulation (TMS), over the left and right superior parietal lobe (SPL) and IPL. We used two different types of visual sustained attention tasks: spatial (location based) and non-spatial (feature based). When the participants performed the spatial task, repetitive TMS (rTMS) over either the right or left IPL induced a significant decrement of sustained attention causing a progressive increment of errors and response time. In contrast, participants' performance was not changed by rTMS on the non-spatial task. Also, omission errors (true negative) gradually increased with time on right and left IPL rTMS conditions, while commission errors (false positive) were relatively stable. These findings suggest that the maintenance of attention, especially in tasks regarding spatial location, is not uniquely lateralized to the right IPL, but may also involve participation of the left IPL.

Aim: Attention deficit has been reported in both schizophrenia patients and patients with major depressive disorder (MDD). The aim of this study was to elucidate the deficits in sustained attention and associated neural network dysfunctions in schizophrenia patients and MDD patients, and to investigate the difference between the two patient groups., Methods: Twelve schizophrenia patients, 12 patients with non-psychotic MDD, and 12 healthy control subjects participated in this study. A sustained attention to response task (SART) was used to measure attention capacity. Cerebral blood flow (CBF) during attention tasks was measured using H(2) (15) O positron emission tomography. Statistical parametric mapping and analysis of covariance were performed to compare the behavioral performance and CBF changes during SART among three groups., Results: Behavioral performances were not significantly different among the three groups except for an increased commission error rate in the schizophrenia group. Regional CBF during SART was significantly reduced in the left inferior frontal gyrus, the left cuneus, and the right superior parietal lobule and increased in the right superior frontal gyrus and the right cuneus in the schizophrenia group compared to the healthy control group. In the MDD group, neither significant regional CBF difference nor behavioral deficit was found compared to the healthy control group., Conclusion: Behavioral performance deficit and perfusion changes in the prefrontal and parietal cortices during SART were observed only in the schizophrenia group. Prefrontal and parietal network dysfunction for sustained attention may be involved in the pathophysiology of schizophrenia., (© 2012 The Authors. Psychiatry and Clinical Neurosciences © 2012 Japanese Society of Psychiatry and Neurology.)

Objective: Delirium is a common and potentially life-threatening clinical syndrome. The authors investigated resting-state functional connectivity in patients with delirium to elucidate possible neural mechanisms underlying this disorder., Method: Twenty-two patients underwent initial functional MRI at rest during an episode of delirium. Of these patients, 14 completed follow-up scans after the episode resolved. Twenty-two comparison subjects without delirium also underwent scanning. The authors assessed cortical functional connectivity using the seed region of the posterior cingulate cortex and functional connectivity strengths between a priori subcortical regions related to acetylcholine and dopamine on data from 20 initial and 13 follow-up scans., Results: Dorsolateral prefrontal cortex activity and posterior cingulate cortex activity were inversely correlated in comparison subjects but strongly correlated in patients during an episode of delirium as indicated by increased functional connectivity between the two regions. Although precuneus activity was positively correlated with posterior cingulate cortex activity in comparison subjects, the correlation was further increased in patients during an episode of delirium, and the increment was associated with less severity and shorter duration of delirium. Functional connectivity strengths of the intralaminar thalamic and caudate nuclei with other subcortical regions were reduced during an episode of delirium but recovered after resolution of the episode., Conclusions: These findings suggest that the disruption in reciprocity of the dorsolateral prefrontal cortex with the posterior cingulate cortex and reversible reduction of functional connectivity of subcortical regions may underlie the pathophysiology of delirium. In addition, enhanced integration in the posteromedial cortices may account for facilitating the rapid improvement of delirium.

It has been proposed that positive emotional biases could make bipolar manic (BM) patients maintain abnormally approaching behaviors during social interactions. To test this hypothesis, we measured interpersonal distance (IPD) and gaze angle of BM patients and normal controls (NCs) during social interaction in immersive virtual environment. Overall, IPDs of BM patients (n = 20) were greater than those of normal controls (n = 20). The IPD difference was even greater between NCs and BM patients with psychotic features (n = 11) than those without psychotic features (n = 9). Regardless of the presence of psychotic features, BM patients averted their gazes more than NCs, and even more while speaking than while listening. Our results might suggest negativistic social cognition of bipolar patients, as was previously found even during a manic phase, or the role of paranoid symptoms in avoidant social behaviors, in agreement with prior studies with schizophrenic patients. Use of proper space and gaze might have psychotherapeutic implication in developing secure, two-person relationship with bipolar patients regardless of the presence of disrupting manic symptoms.

Alcoholism is a disease that affects parts of the brain that control emotion, decisions, and behavior. Therapy for people with alcoholism must address coping skills for facing high-risk situations. Therefore, it is important to develop tools to mimic such conditions. Cue exposure therapy (CET) provides high-risk situations during treatment, which raises the individual's ability to recognize that alcohol craving is being induced. Using CET, it is hard to simulate situations that induce alcohol craving. By contrast, virtual reality (VR) approaches can present realistic situations that cannot be experienced directly in CET. Therefore, we hypothesized that is possible to model social pressure situations using VR. We developed a VR system for inducing alcohol craving under social pressure situations and measured both the induced alcohol craving and head gaze of participants. A 2 x 2 experimental model (alcohol-related locality vs. social pressure) was designed. In situations without an avatar (no social pressure), more alcohol craving was induced if alcohol was present than if it was not. And more alcohol craving was induced in situations with an avatar (social pressure) than in situations without an avatar (no social pressure). The difference of angle between the direction of head gazing and the direction of alcohol or avatar was smaller in situations with an avatar alone (social pressure) than in situations with alcohol alone. In situations with both alcohol and an avatar, the angle between the direction of head gaze and the direction of the avatar was smaller than between the direction of head gaze and the direction of the alcohol. Considering the results, this VR system induces alcohol craving using an avatar that can express various social pressure situations.