Neural effects of a short-term virtual reality self-training program to reduce social anxiety.

BACKGROUND: Social anxiety disorder (SAD) is characterized by anxiety regarding social situations, avoidance of external social stimuli, and negative self-beliefs. Virtual reality self-training (VRS) at home may be a good interim modality for reducing social fears before formal treatment. This study aimed to find neurobiological evidence for the therapeutic effect of VRS. METHODS: Fifty-two patients with SAD were randomly assigned to a VRS or waiting list (WL) group. The VRS group received an eight-session VRS program for 2 weeks, whereas the WL group received no intervention. Clinical assessments and functional magnetic resonance imaging scanning with the distress and speech evaluation tasks were repeatedly performed at baseline and after 3 weeks. RESULTS: The post-VRS assessment showed significantly decreased anxiety and avoidance scores, distress index, and negative evaluation index for 'self', but no change in the negative evaluation index for 'other'. Patients showed significant responses to the distress task in various regions, including both sides of the prefrontal regions, occipital regions, insula, and thalamus, and to the speech evaluation task in the bilateral anterior cingulate cortex. Among these, significant neuronal changes after VRS were observed only in the right lingual gyrus and left thalamus. CONCLUSIONS: VRS-induced improvements in the ability to pay attention to social stimuli without avoidance and even positively modulate emotional cues are based on functional changes in the visual cortices and thalamus. Based on these short-term neuronal changes, VRS can be a first intervention option for individuals with SAD who avoid society or are reluctant to receive formal treatment.

Differences in the modulation of functional connectivity by self-talk tasks between people with low and high life satisfaction.

Self-respect is a practical way to promote life satisfaction through gratifying basic psychological needs, whereas self-criticism is associated with life dissatisfaction. The goal of the present study was to investigate the effect of two positive and negative self-talks on the functional connectome with respect to life satisfaction and its relationships with basic psychological needs. Forty-eight individuals with low life satisfaction (LLS, n â€‹= â€‹24) and with high life satisfaction (HLS, n â€‹= â€‹24) were scanned using functional magnetic resonance imaging at a baseline state and during and after self-respect or self-criticism tasks. Functional connectivity analysis was conducted to identify the modulatory effects of the tasks on the self-referential, default mode, and reward-motivation networks. We found that self-respect changed only the connection between the posterior cingulate cortex (PCC) and frontoparietal network, whereas self-criticism changed almost all of the connections examined. The group x condition interaction effect of self-respect was identified only in connection between the PCC and left ventrolateral prefrontal cortex, while that of self-criticism was observed in various connections based on the ventromedial prefrontal cortex and nucleus accumbens. In respect to basic psychological needs, functional connectivity after self-criticism was significant in predicting the needs of autonomy and relatedness only in the LLS group, whereas functional connectivity after self-respect could predict the needs of autonomy and competence only in the HLS group. Overall, self-criticism produces more noticeable negative changes in the brain than the positive changes of self-respect. Individuals with low life satisfaction may be more vulnerable to be negatively affected not only by self-criticism but also self-respect than individuals with high life satisfaction. The satisfaction of basic psychological needs can play a mediating role in the effects of self-talk tasks differently concerning life satisfaction.

Differences in Brain Areas Affecting Language Function After Stroke.

Background and Purpose- Brain areas associated with functional improvement differ between acute and chronic phases after stroke. This study investigated brain areas associated with language function, according to time after stroke. Methods- Patients with aphasia after stroke were divided into subacute (≤3 months after stroke, 17 patients) and chronic groups (>12 months after stroke, 23 patients). Voxel-wise linear regression analyses in each group were conducted by using fractional anisotropy mapping in diffusion tensor images as a dependent variable, while scores of spontaneous speech, comprehension, repetition, and naming were used as independent variables. Results- Structural connectivity in the left dorsal pathway (eg, superior temporal gyrus, inferior parietal lobule, and superior longitudinal fasciculus) was positively associated with spontaneous speech, repetition, and naming, whereas structural connectivity in the corona radiata, internal capsule, and corpus callosum of the right hemisphere was negatively associated with language function in the subacute phase. Comprehension was associated with the left superior temporal gyrus and the right corona radiata in the subacute phase and the right corpus callosum in the chronic phase (PFWE<0.05). Conclusions- More lateralized language function related to the dorsal pathway was influenced in the bilateral brain areas in the subacute phase but not in the chronic phase. Less lateralized language function related to the ventral pathway was influenced in the bilateral brain areas during both subacute and chronic phases after stroke.

Cortical and subcortical changes in resting-state functional connectivity before and during an episode of postoperative delirium.

OBJECTIVE: Delirium is an acute brain failure related to uncertain problems in neural connectivity, including aberrant functional interactions between remote cortical regions. This study aimed to elucidate the underlying neural mechanisms of delirium by clarifying the changes in resting-state functional connectivity induced by postoperative delirium using imaging data scanned before and after surgery. METHOD: Fifty-eight patients with a femoral neck fracture were preoperatively scanned using resting-state functional magnetic resonance imaging. Twenty-five patients developed postoperative delirium, and 14 of those had follow-up scans during delirium. Eighteen patients without delirium completed follow-up scans 5 or 6 days after surgery. We assessed group differences in voxel-based connectivity, in which the seeds were the posterior cingulate cortex, medial prefrontal cortex and 11 subcortical regions. Connections between the subcortical regions were also examined. RESULTS: The results showed four major findings during delirium. Both the posterior cingulate cortex and medial prefrontal cortex were strongly connected to the dorsolateral prefrontal cortex. The posterior cingulate cortex had hyperconnectivity with the inferior parietal lobule, whereas the medial prefrontal cortex had hyperconnectivity with the frontopolar cortex and hypoconnectivity with the superior frontal gyrus. Connectivity of the striatum with the anterior cingulate cortex and insula was increased. Disconnections were found between the lower subcortical regions including the neurotransmitter origins and the striatum/thalamus in the upper level. CONCLUSIONS: Our findings suggest that cortical dysfunction during delirium is characterized by a diminution of the anticorrelation between the default mode network and task-positive regions, excessive internal connections in the posterior default mode network and a complex imbalance of internal connectivity in the anterior default mode network. These dysfunctions can be attributed to the loss of reciprocity between the default mode network and central executive network associated with defective function in the salience network, which might be closely linked to aberrant subcortical neurotransmission-related connectivity and striato-cortical connectivity.

What is the impact of child abuse on gray matter abnormalities in individuals with major depressive disorder: a case control study.

BACKGROUND: Patients with major depressive disorder (MDD) present heterogeneous clinical symptoms, and childhood abuse is associated with deepening of psychopathology. The aim of this study was to identify structural brain abnormalities in MDD and to assess further differences in gray matter density (GMD) associated with childhood abuse in MDD. METHODS: Differences in regional GMD between 34 MDD patients and 26 healthy controls were assessed using magnetic resonance imaging and optimized voxel-based morphometry. Within the MDD group, further comparisons were performed focusing on the experience of maltreatment during childhood (23 MDD with child abuse vs 11 MDD without child abuse). RESULTS: Compared with healthy controls, the MDD patient group showed decreased GMD in the bilateral orbitofrontal cortices, right superior frontal gyrus, right posterior cingulate gyrus, bilateral middle occipital gyri, and left cuneus. In addition, the patient group showed increased GMD in bilateral postcentral gyri, parieto-occipital cortices, putamina, thalami, and hippocampi, and left cerebellar declive and tuber of vermis. Within the MDD patient group, the subgroup with abuse showed a tendency of decreased GMD in right orbitofrontal cortex, but showed increased GMD in the left postcentral gyrus compared to the subgroup without abuse. CONCLUSIONS: Our findings suggest a complicated dysfunction of networks between cortical-subcortical circuits in MDD. In addition, increased GMD in postcentral gyrus and a possible reduction of GMD in the orbitofrontal cortex of MDD patients with abuse subgroup may be associated with abnormalities of body perception and emotional dysregulation.

A personality trait contributes to the occurrence of postoperative delirium: a prospective study.

BACKGROUND: Although various physical risk factors for delirium have been identified, the effect of psychological aspects is currently unknown. This study aimed to examine psychological risk factors for postoperative delirium and to identify hidden subgroups of delirium in clinical and psychological feature space. METHODS: Among 200 patients with hip fracture, 78 elderly patients were prospectively evaluated for clinical and psychological assessments before surgery. As delirium was assessed from the next day to the 7th day after surgery, postoperative delirium was found in 40 patients, but not in 38 patients. Univariate and multivariate logistic regression analyses were used to explore risk factors for postoperative delirium. Phenotypic subgroups of delirium were assessed using Topological Data Analysis, in which the significant risk factors were used for evaluating filter and distance metrics. RESULTS: Mini-Mental State Examination, neuroticism, conscientiousness, and regional anesthesia were identified as a predictive risk factor for postoperative delirium. The filter metric showed significant negative correlations with nutrition-related factors such as total protein and albumin. When filter metric and Euclidean distances were entered, delirious patients were bifurcated as a function of personality traits and anesthesia method in the patient-patient network. CONCLUSIONS: A personality trait of neuroticism and conscientiousness may predispose elderly patients to postoperative delirium and this influence may be amplified by regional anesthesia. This study verifies the contribution of psychological risk factors to delirium and provides new insight for complex etiologies of delirium by mapping various clinical variables in the topological space.

Influence of first-person and third-person perspectives on neural mechanisms of professional pride.

Professional pride, including self-reflection and attitude toward one's own occupational group, induces individuals to behave in socially appropriate ways, and uniforms can encourage wearers to have this pride. This study was to elucidate the working pattern of professional pride by exploring neural responses when wearing uniforms and being conscious of a third-person's perspective. Twenty healthy adults who had an occupation requiring uniforms were scanned using functional MRI with a self-evaluation task consisting of 2 [uniform versus casual wear] × 2 [first-person perspective versus third-person perspective] conditions. The neural effects of clothing and perspective were analyzed and post-hoc tests were followed. The interaction effect was displayed in the bilateral dorsomedial prefrontal cortex, where uniform led to higher activity in third-person perspective than in first-person perspective, whereas casual wear led to the opposite pattern, suggesting this region may be involved in the awareness of third-person's perspective to uniform-wearing. The right dorsomedial prefrontal cortex showed functional connectivity with the right posterior superior temporal sulcus in uniform-third-person perspective compared to uniform-first-person perspective, suggesting this connection may work for processing information from third-person perspective in a uniform-wearing state. Professional pride may prioritize social information processing in third-person perspective rather than self-referential processing in first-person perspective.

Structural Integrity and Functional Neural Activity Associated with Oral Language Function after Stroke.

(1) Background: The impairment of language function after a stroke is common. It is unclear how the brain reorganizes for language function after cerebral infarction. The aim of this observational study is to investigate the association of structural integrity and functional neural activity with language function in aphasic patients with middle cerebral artery infarction. (2) Methods: Magnetic resonance images and scores from the Western Aphasia Battery on 20 patients were retrieved from medical records. A Voxel-wise linear regression analysis was performed using fractional anisotropy maps or the fractional amplitude of low-frequency fluctuation maps as dependent variables and scores of oral language function as independent variables while controlling for age and time elapsed after stroke. (3) Results: Spontaneous speech was positively associated with fractional anisotropy in the left dorsal stream and the right posterior corpus callosum and with the fractional amplitude of the low-frequency fluctuation of cranial nuclei in the pontomedullary junction. Comprehension was positively associated with the left ventral stream. Naming was positively associated with the left ventral stream and the bilateral occipitofrontal fasciculus, as well as with the fractional amplitude of low-frequency fluctuation of the supramarginal gyrus in the left hemisphere. (4) Conclusions: The dorsal and ventral streams are important for articulation and meaning after the reorganization of neural circuits following stroke. Subdomains of oral language function with a visual component are dependent on the visual association areas located in the right hemisphere.

Lesion-based structural and functional networks in patients with step length asymmetry after stroke.

OBJECTIVE: The aim of this study was to determine common structural and functional networks associated with asymmetric step length after unilateral ischemic stroke. METHODS: Thirty-nine chronic stroke patients were divided into two groups, based on the presence or absence of asymmetric step length. In each group, each lesion was mapped onto a brain magnetic resonance image. The structural and functional networks of brain regions connected to each lesion were identified using a public diffusion tensor and resting state function magnetic resonance image dataset. To identify brain regions associated with asymmetric step length, we conducted voxel-wise independent sample t-tests for structural and function lesion network maps. RESULTS: At least 85% of lesions showed functional network overlap in the bilateral frontal lobe. Functional connectivity of the dorsolateral prefrontal cortex in the contralesional hemisphere was significantly decreased in group 1 compared to that in group 2. CONCLUSIONS: The dorsolateral prefrontal cortex may have an important role in compensating for an asymmetric step length after a unilateral stroke.

Multimodal magnetic resonance imaging correlates of motor outcome after stroke using machine learning.

This study applied machine learning regression to predict motor function after stroke based on multimodal magnetic resonance imaging. Fifty-four stroke patients, who underwent T1 weighted, diffusion tensor, and resting state functional magnetic resonance imaging were retrospectively included. The kernel rigid regression machine algorithm was applied to gray and white matter maps in T1 weighted, fractional anisotropy and mean diffusivity maps in diffusion tensor, and two motor-related independent component analysis maps in resting state functional magnetic resonance imaging to predict Fugl-Meyer motor assessment scores with the covariate as the onset duration after stroke. The results were validated using the leave-one-subject-out cross-validation method. This study is the first to apply machine learning in this area using multimodal magnetic resonance imaging data, which constitutes the main novelty. Multimodal magnetic resonance imaging correctly predicted the Fugl-Meyer motor assessment score in 72 % of cases with a normalized mean squared error of 5.93 (p value = 0.0020). The ipsilesional premotor, periventricular, and contralesional cerebellar areas were shown to be of relatively high importance in the prediction. Machine learning using multimodal magnetic resonance imaging data after a stroke may predict motor outcome.

The effects of positive or negative self-talk on the alteration of brain functional connectivity by performing cognitive tasks.

Self-talk can improve cognitive performance, but the underlying mechanism of such improvement has not been investigated. This study aimed to elucidate the effects of self-talks on functional connectivity associated with cognitive performance. We used the short form of Progressive Matrices Test (sRPM) to measure differences in performance improvements between self-respect and self-criticism. Participants were scanned using functional magnetic resonance imaging in the following order: baseline, during-sRPM1, post-sRPM1, self-respect or self-criticism, during-sRPM2, and post-sRPM2. Analysis was conducted to identify the self-talks' modulatory effects on the reward-motivation, default mode, and central-executive networks. Increase in sRPM2 score compared to sRPM1 score was observed only after self-criticism. The self-talk-by-repetition interaction effect was not found for during-sRPM, but found for post-sRPM; decreased nucleus accumbens-based connectivity was shown after self-criticism compared with self-respect. However, the significant correlations between the connectivity change and performance change appeared only in the self-respect group. Our findings showed that positive self-talk and negative self-talk differently modulate brain states concerning cognitive performance. Self-respect may have both positive and negative effects due to enhanced executive functions and inaccurate confidence, respectively, whereas self-criticism may positively affect cognitive performance by inducing a less confident state that increases internal motivation and attention.

Gait pattern analysis and clinical subgroup identification: a retrospective observational study.

To identify basic gait features and abnormal gait patterns that are common to different neurological or musculoskeletal conditions, such as cerebral stroke, Parkinsonian disorders, radiculopathy, and musculoskeletal pain.In this retrospective study, temporal-spatial, kinematic, and kinetic gait parameters were analyzed in 424 patients with hemiplegia after stroke, 205 patients with Parkinsonian disorders, 216 patients with radiculopathy, 167 patients with musculoskeletal pain, and 316 normal controls (total, 1328 subjects). We assessed differences according to the condition and used a community detection algorithm to identify subgroups within each condition. Additionally, we developed a prediction model for subgroup classification according to gait speed and maximal hip extension in the stance phase.The main findings can be summarized as follows. First, there was an asymmetric decrease of the knee/ankle flexion angles in hemiplegia and a marked reduction of the hip/knee range of motion with increased moment in Parkinsonian disorders. Second, three abnormal gait patterns, including fast gait speed with adequate maximal hip extension, fast gait speed with inadequate maximal hip extension, and slow gait speed, were found throughout the conditions examined. Third, our simple prediction model based on gait speed and maximal hip extension angle was characterized by a high degree of accuracy in predicting subgroups within a condition.Our findings suggest the existence of specific gait patterns within and across conditions. Our novel subgrouping algorithm can be employed in routine clinical settings to classify abnormal gait patterns in various neurological disorders and guide the therapeutic approach and monitoring.

Neural Basis of Ambivalence towards Ideal Self-Image in Schizophrenia.

OBJECTIVE: Little has been explored about a reflection towards self-image in schizophrenia, though it can be related to heterogeneous symptoms of the illness. We identified the neural basis of ambivalence towards ideal self-image in patients with schizophrenia. METHODS: 20 patients with schizophrenia and 20 healthy controls underwent functional MRI while the self-image reflection tasks of determining whether to agree with sentences describing their actual or ideal self-image that contained one of the adjective pairs with opposite valence. The interaction between the group and ideal ambivalence score was examined, and group differences in functional connectivity related to ambivalence towards ideal self-image were further studied. RESULTS: The interaction of group-by-ideal ambivalence score was shown in the dorsal anterior cingulate cortex and dorsolateral prefrontal cortex, where activities were positively correlated with the level of ideal self-image ambivalence in patients, but not in controls. Task-related decrease in functional connectivity was shown between the orbitofrontal cortex and cerebellum in patients. CONCLUSION: The process of reflecting on ambivalent ideal self-image in schizophrenia may be related to aberrant prefrontal activity and connectivity. Abnormality in the prefrontal regions that take part in cognitive conflict monitoring and value judgment may underlie the pathophysiology of increased ambivalence towards ideal self-image.

Characterization of idiopathic Parkinson's disease subgroups using quantitative gait analysis and corresponding subregional striatal uptake visualized using 18F-FP-CIT positron emission tomography.

BACKGROUND: Gait disturbance is one of the most common symptoms among patients with idiopathic Parkinson's disease (IPD). Nevertheless, Parkinson's disease subtype clustering according to gait characteristics has not been thoroughly investigated. RESEARCH QUESTION: The aim of this study was to identify subgroups according to gait pattern among patients with IPD. METHODS: This study included 88 patients with IPD who underwent 18F-fluorinated-N-3-fluoropropyl-2-ß-carboxymethoxy-3-ß-4-iodophenyl-nortropane positron emission tomography (18F-FP-CIT PET) and three-dimensional gait analysis (3DGA) between January 1, 2014 and December 31, 2016. We performed cluster analysis using temporal-spatial gait variables (gait speed, stride length, cadence, and step width) and divided patients into four subgroups. The kinematic and kinetic gait variables in 3DGA were compared among the four subgroups. Furthermore, we compared the uptake patterns of striatum among the four subgroups using 18F-FP-CIT PET. RESULTS: The patients were clustered into subgroups based on gait hypokinesia and cadence compensation. Group 1 had decreased stride length compensating with increased cadence. Group 2 had decreased stride length without cadence compensation and wider step width. Group 3 had relatively spared stride length with decreased cadence. Group 4 had spared stride length and cadence. The uptake of posterior putamen was significantly decreased in Group 3 compared with Group 4. SIGNIFICANCE: Gait hypokinesia and cadence can help to classify gait patterns in IPD patients. Our subgroups may reflect the different gait patterns in IPD patients.

Choice of Leisure Activities by Adolescents and Adults With Internet Gaming Disorder: Development and Feasibility Study of a Virtual Reality Program.

BACKGROUND: Excessive internet game use frequently leads to various physical, psychological, and social problems, and internet gaming disorder (IGD) has become a serious public health issue worldwide. Recently, virtual reality (VR) therapy has emerged as a promising method to increase psychological treatment motivation and accessibility. However, few studies have examined the potential of VR technology for the management of IGD, and VR content tailored to IGD characteristics remains scarce. OBJECTIVE: This preliminary study aimed to examine the potential of a VR-based program that was designed to help users identify their leisure time use patterns, especially those related to gaming, and to modify their gaming overuse by alternative activities provided in the VR content. Moreover, to investigate whether users' VR activities reflect various clinical variables of IGD in youth, we examined the relationships among the leisure time activity selection pattern, built-in response, and speech data obtained from the VR program, as well as symptom severity of internet gaming, psychiatric comorbidities, and motivation of participants reported through relevant questionnaire data. METHODS: Three types of VR content (understanding my daily activities at home, finding an alternative activity to internet gaming at home, expressing contradictory opinions toward a friend's gaming beliefs) were developed by simulating the daily situations in which patients with IGD can select alternative free-time leisure activities. We examined internet addiction, mental health problems, and motivation for 23 IGD and 29 control participants. Behavioral and self-rated responses from VR, such as alternative activity selection data and speech patterns (speech time, speech satisfaction, and speech accordance), and results from various questionnaires were compared between groups. The correlations between IGD behaviors in VR and real-life behaviors assessed by questionnaire measures were analyzed. RESULTS: Significant correlations were found between internet gaming behavior and user activity data, such as speech and activity selection pattern, in our VR program. Our results showed that the IGD group had fewer leisure activities and preferred game or digital activities to other types of activities compared to controls, even in VR. There was a positive relationship between the viability of alternative leisure activities the participants selected in VR and the amount of perceived satisfaction from that activity (r=.748, P<.001). Speech accordance in the IGD group was lower than in the control group and was correlated negatively with Internet Addiction Test and Internet Addiction Test-gaming scores (r=.300, P=.03) but positively with users' motivation (r=.312, P=.02). CONCLUSIONS: The results from our VR program can provide information about daily activity patterns of youths with IGD and the relationship between user VR activities and IGD symptoms, which can be useful in applying VR technology to IGD management.

Bihemispheric changes associated with cognition in patients with chronic brainstem stroke.

OBJECTIVE: We aimed to identify brain changes associated with preserved cognitive function in patients with chronic brainstem stroke. METHODS: Twelve patients with chronic brainstem stroke and 24 age-matched healthy controls were included in this retrospective study. All participants underwent T1-weighted, diffusion tensor, and resting-state functional MRI. Gray matter density, fractional anisotropy, and mean diffusivity maps from diffusion tensor imaging and seven cognition-related independent component maps from resting-state functional MRI were used to identify differences in brain volume, structural connectivity, and functional connectivity. Independent t-tests were used to determine the statistical significance of changes in gray matter density, fractional anisotropy, mean diffusivity, and inter-network functional connectivity maps. RESULTS: Bilateral cerebellum volumes and structural connectivity of the diffuse bilateral cerebral hemispheres were significantly lower in the patient than in the control group. However, patients exhibited increased gray matter volume and increased structural connectivity of the temporal lobe in the contra-lesional hemisphere and basal forebrain, compared with healthy controls. Furthermore, the intra-network functional connectivity in the frontal and temporal lobes was significantly higher in patients than in controls (PFWE < 0.05). CONCLUSION: In the patient group, the brain regions mainly associated with the cholinergic system exhibited increased volume, structural connectivity, and functional connectivity. In contrast, the regions connected with the brainstem via cortico-ponto-cerebellar fibers exhibited decreased volume or structural connectivity. Cognitive function may be preserved in patients with brainstem stroke due to significant increases in frontal and temporal inter-network connectivity.

Neural Basis of Professional Pride in the Reaction to Uniform Wear.

Professional pride is a positive emotion that includes self-reflection or evaluation and attitude toward one's own occupational group. Uniforms can encourage the wearer to have professional pride. The current study aimed to elucidate the neural basis of professional pride using an experimental task related to the self in uniform and functional magnetic resonance imaging (fMRI). The person-adjective matching task, in which a participant or other in uniform or casual wear was presented with positive and negative words, was used for scanning fMRI. Imaging data from 21 adults who had an occupation requiring a uniform were analyzed to identify the main and interaction effects of individual (self vs. other), clothes (uniform vs. casual wear), and valence (positive vs. negative). Identified brain activities were correlated with psychological scales including the Rosenberg Self-esteem Scale and Group Environment Questionnaire. Whole brain analyses found that the interaction between individual and clothes was present in multiple regions such as the right ventrolateral prefrontal cortex (VLPFC), left dorsolateral prefrontal cortex, left middle and inferior temporal gyri, left posterior superior temporal sulcus, right temporoparietal junction, left lingual gyrus, left calcarine cortex, right insula, left caudate, and right putamen. In particular, activities in the right VLPFC, left calcarine cortex, and right putamen in the self/uniform condition were positively correlated with several psychological scales. These results suggest that professional pride may be represented through multiple brain networks related to empathy, reward, and emotion regulation as well as the theory-of-mind network. The neural basis of professional pride is closely related to positive self-evaluation and group cohesion.

Structural and functional connectivity correlates with motor impairment in chronic supratentorial stroke: a multimodal magnetic resonance imaging study.

The aim of this study was to identify differences in structural and functional brain connectivity between poststroke mild and severe motor impairment. Twenty-four chronic stroke patients who underwent resting-state functional MRI and diffusion tensor image were retrospectively included. All patients were classified into two groups (mild motor impairment: 11 patients and severe motor impairment: 13 patients) according to their Fugl-Meyer motor assessment score. Tract-based spatial statistics and group independent component analyses were applied to investigate between-group differences in structural and functional connectivity, respectively. The fractional anisotropy values of motor-related brain regions in the affected hemisphere were significantly higher in mild motor impairment than in severe motor impairment (corrected P<0.05). The internetwork functional connectivity between (i) the supplementary motor area and primary motor cortex in the affected hemisphere, (ii) the supplementary motor area and dorsolateral prefrontal cortex in the unaffected hemisphere, and (iii) the ischemic lesion and primary motor cortex in the unaffected hemisphere was significantly higher in mild motor impairment than in severe motor impairment (PFWE<0.05). Better motor recovery after stroke could be facilitated by means of treatments aimed at enhancing structural and functional connectivity among motor-related brain regions such as noninvasive brain stimulation and neurodevelopmental therapy.

Different neural substrates at first impressions of same-sex and opposite-sex faces in women.

First impressions follow a complex process that is greatly influenced by the facial attributes and the sex of the displayer. This study aimed to evaluate whether the initial impression formed in friendship decisions is processed differently between the same-sex and opposite-sex targets in women. Twenty-four healthy female volunteers participated in a functional magnetic resonance imaging experiment, in which they appraised a given face and decided whether they wanted to befriend the target. Then, a post-scan subjective rating was performed for facial components such as cheerfulness, good-looks, and uniqueness. The data were used to perform univariate whole-brain analysis to identify the neural substrates of sex bias in impression formation, and exploratory parametric modulation analysis to examine the parametric effects of facial components. Results showed that a composite of diverse areas including the dorsolateral prefrontal cortex, dorsomedial prefrontal cortex, anterior cingulate cortex, and posterior superior temporal sulcus were more engaged when viewing male faces than female faces. Parametric analysis revealed that bilateral lingual gyrus activities showed a negative parametric effect with cheerfulness for male faces, whereas left inferior parietal lobule activity showed a positive parametric effect with good-looks for female faces. During the formation of first impressions, diffuse areas related to emotion processing and conflict-monitoring were utilized when a person of the opposite sex was encountered compared to encounters with a person of the same sex. The perceived cheerfulness of a male face also showed a negative relationship with the identification of facial emotion in the male face; the more a female face was considered good-looking, a greater feeling of uneasiness appeared to be elicited. The findings from this study provide further evidence of sex bias in women during friendship encounters.

Altered structural connectivity associated with motor improvement in chronic supratentorial ischemic stroke.

This study aimed to identify brain structural changes associated with motor recovery, after neurorehabilitation in patients with chronic supratentorial ischemic stroke. Twenty-one chronic stroke patients with an improved Fugl-Meyer motor assessment score were retrospectively included in the study. All participants underwent diffusion tensor imaging twice: before and after the outpatient neurorehabilitation program. A fractional anisotropy map, derived from diffusion tensor imaging, was used to identify changes in brain structural connectivity. A paired t-test of the fractional anisotropy maps was performed to calculate statistical significance. Structural connectivity was significantly increased along the corticospinal tract pathway in the ipsilesional hemisphere (uncorrected P<0.005 with cluster size>10 voxels). The posterior corpus callosum, which connects the bilateral hemispheres, and the bilateral middle cerebellar peduncle, which is the main pathway of the afferent fibers from the cerebrum to cerebellum, also showed significantly increased structural connectivity (uncorrected P<0.005 with cluster size>10 voxels). Motor-associated brain regions, mainly in the ipsilesional hemisphere, were involved in motor improvements in patients with chronic supratentorial ischemic stroke. These findings could be incorporated into the neurorehabilitation of chronic stroke patients for improved motor recovery.