Bilateral Inferior Parietal Lobule Research Articles

The Stroop effect: An activation likelihood estimation meta-analysis in healthy young adults

Age plays a significant role in executive control processes in the Stroop task. This study aims to draw together the Stroop tasks to determine the role of the frontal cortex in cognitive control among healthy young adults using activation likelihood estimation. Forty-six studies were selected according to the fMRI neuroimaging tools, Stroop experimental tasks, young participants’ age. The results showed that the contrast of incongruent conditions and congruent conditions revealed 7 significant clusters, including the right cingulate cortex, left dorsolateral prefrontal cortex, bilateral inferior frontal gyrus, right superior frontal gyrus and temporal cortex. In addition, the contrast comparing incongruent conditions with neutral conditions activated a network including the right inferior frontal gyrus, left dorsolateral prefrontal cortex, bilateral medial frontal cortex, left insular cortex and bilateral inferior parietal lobule and precuneus. In this study, we found that the brain areas for executive performance had a higher concordance in the frontal cortex among healthy young adults than temporal-parietal network.

Distinct Disruptive Patterns of Default Mode Subnetwork Connectivity Across the Spectrum of Preclinical Alzheimer's Disease.

Background: The early progression continuum of Alzheimer’s disease (AD) has been considered to advance through subjective cognitive decline (SCD), non-amnestic mild cognitive impairment (naMCI), and amnestic mild cognitive impairment (aMCI). Altered functional connectivity (FC) in the default mode network (DMN) is regarded as a hallmark of AD. Furthermore, the DMN can be divided into two subnetworks, the anterior and posterior subnetworks. However, little is known about distinct disruptive patterns in the subsystems of the DMN across the preclinical AD spectrum. This study investigated the connectivity patterns of anterior DMN (aDMN) and posterior DMN (pDMN) across the preclinical AD spectrum.Methods: Resting-state functional magnetic resonance imaging (rs-fMRI) was used to investigate the FC in the DMN subnetworks in 20 healthy controls (HC), eight SCD, 11 naMCI, and 28 aMCI patients. Moreover, a correlation analysis was used to examine associations between the altered connectivity of the DMN subnetworks and the neurocognitive performance.Results: Compared to the HC, SCD patients showed increased FC in the bilateral superior frontal gyrus (SFG), naMCI patients showed increased FC in the left inferior parietal lobule (IPL), and aMCI patients showed increased FC in the bilateral IPL in the aDMN; while SCD patients showed decreased FC in the precuneus, naMCI patients showed increased FC in the left middle temporal gyrus (MTG), and aMCI patients also showed increased FC in the right middle frontal gyrus (MFG) in the pDMN. Notably, the FC between the ventromedial prefrontal cortex (vmPFC) and the left MFG and the IPL in the aDMN was associated with episodic memory in the SCD and aMCI groups. Interestingly, the FC between the posterior cingulated cortex (PCC) and several regions in the pDMN was associated with other cognitive functions in the SCD and naMCI groups.Conclusions: This study demonstrates that the three preclinical stages of AD exhibit distinct FC alternations in the DMN subnetworks. Furthermore, the patient group data showed that the altered FC involves cognitive function. These findings can provide novel insights for tailored clinical intervention across the preclinical AD spectrum.

Transcranial direct current stimulation of default mode network parietal nodes decreases negative mind-wandering about the past.

Mind-wandering is a cognitive process in which people spontaneously have thoughts that are unrelated to their current activities. The types of mind-wandering thoughts that people have when affected by a negative mood resemble thoughts associated with mood disorders (e.g., negative thoughts about the past). Transcranial direct current stimulation (tDCS) is a form of noninvasive brain stimulation that can modulate cognition and affect in healthy and clinical populations. Ninety participants received either excitatory, inhibitory, or sham tDCS to bilateral inferior parietal lobe (IPL) nodes of the default mode network (DMN) to assess changes in maladaptive mind-wandering following criticism. tDCS did not change mind-wandering frequency after hearing criticism, but it did change what people mind-wandered about. Specifically, cathodal stimulation decreased the frequency of negative mind-wandering thoughts about the past. Future studies could investigate tDCS of DMN regions as an intervention for patients with mood disorders who suffer from negative, past-oriented cognitions.

The relationship between individual differences in gray matter volume and religiosity and mystical experiences: A preregistered voxel-based morphometry study.

The neural substrates of religious belief and experience are an intriguing though contentious topic. Here, we had the unique opportunity to establish the relation between validated measures of religiosity and gray matter volume in a large sample of participants (N = 211). In this registered report, we conducted a confirmatory voxel‐based morphometry analysis to test three central hypotheses regarding the relationship between religiosity and mystical experiences and gray matter volume. The preregisterered hypotheses, analysis plan, preprocessing and analysis code and statistical brain maps are all available from online repositories. By using a region‐of‐interest analysis, we found no evidence that religiosity is associated with a reduced volume of the orbito‐frontal cortex and changes in the structure of the bilateral inferior parietal lobes. Neither did we find support for the notion that mystical experiences are associated with a reduced volume of the hippocampus, the right middle temporal gyrus or with the inferior parietal lobes. A whole‐brain analysis furthermore indicated that no structural brain differences were found in association with religiosity and mystical experiences. We believe that the search for the neural correlates of religious beliefs and experiences should therefore shift focus from studying structural brain differences to a functional and multivariate approach.

Application of T1-/T2-Weighted Ratio Mapping to Elucidate Intracortical Demyelination Process in the Alzheimer's Disease Continuum.

Background The biological diagnosis criteria of the Alzheimer’s disease (AD) suggests that previous work may misclassify the cognitive impairment caused by other factors into AD. Consequently, re-assessing the imaging profile of AD continuum is needed. Considering the high vulnerability of cortical association fibers, we aimed to elucidate the cortical demyelination process in the AD continuum biologically defined.Methods According to the biological diagnosis criteria, we determined the positive amyloid status (A+) as cerebrospinal fluid (CSF) amyloid1–42 < 192 pg/ml, Florbetapir Positron emission tomography (PET) composite standardized uptake value ratio (SUVR) >1.11. Also, the positive Tau status (T+) was determined as p-Tau181 > 23 pg/ml. Based on the cognitive characterization, we further categorized 252 subjects into 27 cognitively unimpaired with normal AD biomarkers (A−T−, controls), 49 preclinical AD (A+T+), 113 AD with mild cognitive impairment (MCI) (A+T+), and 63 AD dementia (A+T+). We estimated the intracortical myelin content used the T1- and T2-weighted (T1W/T2W) ratio mapping. To investigate the sensitivity of the ratio mapping, we also utilized well-validated AD imaging biomarkers as the reference, including gray matter volume and Fludeoxyglucose PET (FDG-PET). Based on the general linear model, we conducted the voxel-wise two-sample T-tests between the controls and each group in the AD continuum.Results Compared to the controls, the results showed that the preclinical AD patients exhibited decreased T1W/T2W ratio value in the right inferior parietal lobule (IPL); as the disease progresses, the prodromal AD patients demonstrated lower ratio value in bilateral IPL, with hippocampus (HP) atrophy. Lastly, the AD dementia patients exhibited decreased ratio value in bilateral IPL and hippocampus; also, we observed the bilateral temporal cortices atrophy and widespread decreased metabolism in the AD dementia patients. After corrected with gray volume, the results remained mostly unchanged.Conclusion Our study implied the decreased right IPL T1W/T2W ratio might represent early AD-related demyelination in disease continuum. Additionally, we demonstrated that the T1W/T2W ratio mapping is an easy-to-implement and sensitive metric to assess the intracortical myelin content in AD, particularly in the early stage.

Dissociative changes in gray matter volume following electroconvulsive therapy in major depressive disorder: a longitudinal structural magnetic resonance imaging study.

Electroconvulsive therapy (ECT), has become a widely applied potent treatment in clinical practice for major depressive disorder (MDD) over decades. However, due to its nonspecific and spatially unfocused nature, the underlying mechanisms of ECT remain unclear. In this longitudinal study, 11 patients with MDD underwent magnetic resonance imaging (MRI) before and after ECT at three different time points. A longitudinal voxel-based morphology approach was performed to characterize dynamic changes in brain gray matter volume (GMV). Twelve age- and sex-matched healthy controls were recruited to identify structural brain changes of patients with MDD before and after ECT. The brain GMV was globally found to increase shortly after a series of ECT, and then decrease 1month after ECT treatment exposure. This fluctuating tendency was localized to the bilateral inferior parietal lobes, bilateral insula, and right superior temporal cortex. After the global GMV was corrected, there were only significant global effect increases in GMV in the left anterior hippocampus and right caudate, which were both significantly correlated with the improvement of depression symptoms. However, 1month after ECT treatments, there was still significantly reduced GMV following patients with MDD compared to healthy controls in the left putamen, right anterior cingulate, and left inferior temporal cortex, which was observed before ECT. These findings indicate that ECT in patients with MDD is closely associated with dissociative structural changes. The locally enhanced GMV in limbic areas may reflect that the ECT-related brain compensatory mechanisms contribute to brain structure recovery in MDD.

Altered Global Synchronizations in Patients With Parkinson's Disease: A Resting-State fMRI Study.

Background: Abnormalities of cognitive and movement functions are widely reported in Parkinson’s disease (PD). The mechanisms therein are complicated and assumed to a coordination of various brain regions. This study explored the alterations of global synchronizations of brain activities and investigated the neural correlations of cognitive and movement function in PD patients.Methods: Thirty-five age-matched patients with PD and 35 normal controls (NC) were enrolled in resting-state functional magnetic resonance imaging (rs-fMRI) scanning. Degree centrality (DC) was calculated to measure the global synchronizations of brain activity for two groups. Neural correlations between DC and cognitive function Frontal Assessment Battery (FAB), as well as movement function Unified Parkinson’s Disease Rating Scale (UPDRS-III), were examined across the whole brain within Anatomical Automatic Labeling (AAL) templates.Results: In the PD group, increased DC was observed in left fusiform gyrus extending to inferior temporal gyrus, left middle temporal gyrus (MTG) and angular gyrus, while it was decreased in right inferior opercular-frontal gyrus extending to superior temporal gyrus (STG). The DC in a significant region of the fusiform gyrus was positively correlated with UPDRS-III scores in PD (r = 0.41, p = 0.0145). Higher FAB scores were shown in NC than PD (p < 0.0001). Correlative analysis of PD between DC and FAB showed negative results (p < 0.05) in frontal cortex, whereas positive in insula and cerebellum. As for the correlations between DC and UPDRS-III, negative correlation (p < 0.05) was observed in bilateral inferior parietal lobule (IPL) and right cerebellum, whereas positive correlation (p < 0.05) in bilateral hippocampus and para-hippocampus gyrus (p < 0.01).Conclusion: The altered global synchronizations revealed altered cognitive and movement functions in PD. The findings suggested that the global functional connectivity in fusiform gyrus, cerebellum and hippocampus gyrus are critical regions in the identification of cognitive and movement functions in PD. This study provides new insights on the interactions among global coordination of brain activity, cognitive and movement functions in PD.

Therapeutic effect of the combined treatment with acupuncture and venlafaxine hydrochloride on depression based on diffusion tensor imaging technology

To explore the effectiveness and safety of the combined treatment with acupuncture and venlafaxine hydrochloride on depression in terms of the microstructure change of white matter fiber tracts of brain based on diffusion tensor imaging technology (DTI). The prospective study design was adopted. All of 60 patients with depression were randomized into an acupuncture-medication group and a medication group, 30 cases in each one. In the medication group, venlafaxine hydrochloride was used, 75 mg per day in the 1st week, 150 mg per day in the 2nd week and 225 mg per day from the 3rd to 6th week. In the acupuncture-medication group, on the base of the treatment in the medication group, acupuncture was combined. Baihui (GV 20) and Yintang (GV 29) were the main acupoints. The supplementary acupoints were selected according to the clinical symptoms of individuals. The needles were retained for 30 min. Acupuncture was provided once every 2 days, 3 times a week. The consecutive 12 weeks of treatment were required in the two groups. Additionally, a normal group was prepared with 30 healthy volunteers. Separately, before treatment, in 2, 8 and 12 weeks of treatment, Hamilton's depression scale (HAMD-17), Beck depression inventory scale (BDI) and the antidepressant side effect scale (SERS) were adopted to evaluate the effectiveness and safety of the two groups. Moreover, before and after 12 weeks of treatment, DTI was adopted to detect the fractional anisotropy score (FA) of each brain region in the patients. After treatment, the scores of HAMD-17 and BDI were all reduced in the two groups (P<0.05). In 8 and 12 weeks of treatment, the scores of HAMD-17 and BDI in the acupuncture-medication group were less than those in the medication group (P<0.05). The difference in SERS score was not significant statistically between the two groups (P>0.05). Compared with the healthy volunteers, FA scores in 6 brain regions changed obviously in the patients with depression, including the white matter of bilateral frontal lobes, splenium of corpus callosum, left cingulated gyrus, white matter of bilateral inferior temporal gyrus, white matter of bilateral inferior parietal lobe and white matter of bilateral deep temporal occipital region separately. Before treatment, the differences in FA scores of these 6 brain regions were not significant statistically between the two groups (P>0.05). After treatment, FA scores in the white matter of bilateral frontal lobes, white matter of bilateral inferior temporal gyrus and white matter of bilateral deep temporal occipital region in the acupuncture-medication group were all higher than those in the medication group (P<0.05). Acupuncture repairs the brain white matter fiber tracts in some brain regions to certain extent and the therapeutic effects are enhanced with the adjuvant medication of venlafaxine hydrochloride.

Using resting-state DMN effective connectivity to characterize the neurofunctional architecture of empathy

Neuroimaging studies in social neuroscience have largely relied on functional connectivity (FC) methods to characterize the functional integration between different brain regions. However, these methods have limited utility in social-cognitive studies that aim to understand the directed information flow among brain areas that underlies complex psychological processes. In this study we combined functional and effective connectivity approaches to characterize the functional integration within the Default Mode Network (DMN) and its role in self-perceived empathy. Forty-two participants underwent a resting state fMRI scan and completed a questionnaire of dyadic empathy. Independent Component Analysis (ICA) showed that higher empathy scores were associated with an increased contribution of the medial prefrontal cortex (mPFC) to the DMN spatial mode. Dynamic causal modelling (DCM) combined with Canonical Variance Analysis (CVA) revealed that this association was mediated indirectly by the posterior cingulate cortex (PCC) via the right inferior parietal lobule (IPL). More specifically, in participants with higher scores in empathy, the PCC had a greater effect on bilateral IPL and the right IPL had a greater influence on mPFC. These results highlight the importance of using analytic approaches that address directed and hierarchical connectivity within networks, when studying complex psychological phenomena, such as empathy.

A coordinate-based meta-analysis of the n-back working memory paradigm using activation likelihood estimation

The n-back task is a classical paradigm for functional neuroimaging studies of working memory (WM). The frontal and parietal cortical regions are known to be activated during the task. We used activation likelihood estimation (ALE) to conduct a quantitative meta-analysis of 96 primary studies of n-back task variants based on four conditions: memory loads (1-back, 2-back), object (identity, location), age (younger, older) and gender (male, female). Six cortical regions were consistently activated across all the studies: bilateral middle frontal gyrus (BA 10); bilateral inferior parietal lobule (BA 40); bilateral precuneus (BA 7); left superior frontal gyrus (BA 6); left anterior insula (aI) (BA 13); bilateral thalamus. Further meta-analyses revealed that different regions were sensitive to different conditions: compared with 1-back, 2-back increased activation in left middle frontal gyrus, left inferior frontal gyrus and left aI; compared with object location, object identity increased activation in right aI; young, compared with older subjects showed increased activation in frontal, parietal lobule, and right aI; the comparison between male and female showed no differences. Thus, our findings, showed consistent activation of frontal and parietal cortical regions, while other regions such as the aI, showed different activation patterns depending on varying experimental classification conditions.

Neurofeedback of core language network nodes modulates connectivity with the default-mode network: A double-blind fMRI neurofeedback study on auditory verbal hallucinations

BackgroundThe experience of auditory verbal hallucinations in schizophrenia is associated with changes in brain network function. In particular, studies indicate altered functional coupling between nodes of the language and default mode networks. Neurofeedback based on real-time functional magnetic resonance imaging (rtfMRI) can be used to modulate such aberrant network connectivity. MethodsWe investigated resting-state connectivity changes after neurofeedback (NF) in 21 patients with schizophrenia and 35 healthy individuals. All participants underwent two days of neurofeedback training of important nodes of the left-hemispheric language network including the inferior frontal gyrus (IFG) and posterior superior temporal gyrus (pSTG). In a double-blind randomized cross-over design, participants learned to down- and up-regulate their brain activation in the designated target regions based on NF. Prior to and after each training day, a resting state measurement took place. ResultsCoupling between nodes of the language and the default mode network (DMN) selectively increased after down-as compared to up-regulation NF. Network analyses revealed more pronounced increases in functional connectivity between nodes of the language network and the DMN in patients compared to healthy individuals. In particular, down-regulation NF led to increased coupling between nodes of the language network and bilateral inferior parietal lobe (IPL) as well as posterior cingulate cortex (PCC)/precuneus in patients. Up-regulation strengthened connectivity with the medial prefrontal cortex (mPFC). Improved well-being four weeks after the training predicted increased functional coupling between the left IFG and left IPL. ConclusionModulatory effects emerged as increased internetwork communication, indicating that down-regulation NF selectively enhances coupling between language and DM network nodes in patients with AVH. RtfMRI NF may thus be used to modulate brain network function that is relevant to the phenomenology of AVH. Specific effects of self-regulation on symptom improvement have to be explored in therapeutic interventions.

Fractional amplitude of low-frequency fluctuations and functional connectivity in comatose patients subjected to resting-state functional magnetic resonance imaging

Objective:The objective of the study is to investigate the changes of fractional amplitude of low-frequency fluctuations (fALFFs) and functional connectivity (FC) in the brain function of comatose patients with resting-state blood-oxygenation-level-dependent functional magnetic resonance imaging (BOLD-fMRI) and to discuss the underlying neurophysiological mechanism of disease.Materials and Methods:Resting-state BOLD-fMRI scans were conducted on 20 comatose patients and 20 age-matched and gender-matched controls. The differences of fALFF between two groups were analyzed with two-sample t-test; significant differences of connectivity between groups were acquired to calculate the FC of the precuneus with other brain regions.Results:Compared to the control group, the comatose patients exhibited a significant reduction in fALFF in various areas, including the right cingulate gyrus, left precuneus, right inferior parietal lobule, right superior parietal lobule, bilateral anterior/posterior central gyrus, middle frontal gyrus, right superior frontal gyrus, right superior temporal gyrus, and the bilateral cerebellar hemispheres (P < 0.05, Alphasim correction). Compared with controls, the brain region FC correlated with the precuneus reduced mainly located in the bilateral inferior parietal lobule, posterior central gyrus, lenticular nucleus, left anterior central gyrus, left medial frontal gyrus, left anterior lobe of the cerebellum, right insula, right transverse temporal gyri, and right thalamus. Regions whose FC increased include the left superior frontal gyrus, left side of the callosum, left superior parietal lobule, and both sides of the cingulate (P < 0.05, Alphasim correction).Conclusion:Measurements of fALFF and FC obtained by resting-state BOLD-fMRI could provide considerable information for the analysis and evaluation of the brain function of comatose patients from the perspective of local function and global functional network and provide the theoretical basis for the study of coma nerve physiological mechanism.

Decreased Gray Matter Volume of Right Inferior Parietal Lobule Is Associated With Severity of Mental Disorientation in Patients With Mild Cognitive Impairment.

Background: Mental disorientation in time, space, and with respect to people is common in patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI). Recently, a high-resolution functional MRI (fMRI) study revealed that the inferior parietal lobule (IPL) and precuneus are important regions related to mental orientation in healthy individuals. We hypothesized that the IPL and/or precuneus are crucial regions for mental disorientation in patients with amnestic MCI (aMCI). Therefore, our aim was to assess our hypothesis in these patients using voxel-based morphometry (VBM).Methods: Fifteen patients with aMCI participated. The Neurobehavioral Cognitive Status Examination (COGNISTAT) as well as the Mini-Mental State Examination (MMSE) were used to evaluate mental disorientation. Subsequently, we used VBM analysis to identify brain regions that exhibited gray matter (GM) volume loss associated with mental disorientation. Based on our hypothesis, four brain regions (bilateral IPLs and precuneus) were selected as regions of interest (ROIs).Results: We found a significant decreased GM volume in the right IPL, which was correlated with lower orientation scores on the COGNISTAT. In contrast, GM volume in other ROIs did not show a significant positive correlation with mental disorientation. Regarding the MMSE, no significant reduction in GM associated with decline in orientation were observed in any ROI.Conclusion: We found the significant relationship between low GM volume in the right IPL and severity of mental disorientation. Therefore, the right IPL is responsible for mental disorientation in aMCI.

Altered Default Mode and Sensorimotor Network Connectivity With Striatal Subregions in Primary Insomnia: A Resting-State Multi-Band fMRI Study.

Background: Primary insomnia is a high prevalent sleep disorder. Disturbed brain activity during reward, emotional, and cognitive processing have been observed in insomnia patients. Studies have implicated a critical role of the striatum in these dysfunctions. However, there have been no direct investigations on the whole-brain functional connectivity (FC) of the striatum in insomnia.Methods: We analyzed the group differences in the FC images of 6 predefined striatal subregions based on the multi-band resting-state fMRI data of 18 insomnia patients and 16 healthy controls.Results: We found increased positive FC in the bilateral medial frontal gyrus for bilateral dorsal caudate (DC) and left inferior ventral striatum (VS) subregions, but increased negative FC in the bilateral inferior parietal lobe for the left inferior VSi and right dorsal caudal putamen (DCP) subregions, and in the lateral temporal, occipital, and primary sensorimotor areas for the bilateral DC and left superior VS subregions. The FC between the right DCP and right inferior parietal lobe showed significant positive correlation with Pittsburgh Sleep Quality Index (PSQI).Conclusion: The findings indicate disturbed striatal FC with the default mode network (DMN), the visual and somatosensory areas in insomnia, which likely reflects an inappropriate reward or emotional significance attribute to self-reflection, episodic memory, sensory-perception processes. The altered striatal FC might increase the risk of insomnia patients to develop depression and anxiety.

Functional Connectivity of Anterior Insula Predicts Recovery of Patients With Disorders of Consciousness.

Background: We hypothesize that the anterior insula is important for maintenance of awareness. Here, we explored the functional connectivity alterations of the anterior insula with changes in the consciousness level or over time in patients with disorders of consciousness (DOC) and determined potential correlation with clinical outcomes.Methods: We examined 20 participants (9 patients with DOC and 11 healthy controls). Each patient underwent resting-state functional magnetic resonance imaging (rs-fMRI) and a standardized Coma Recovery Scale-Revised (CRS-R) assessment on the same day. We categorized the patients according to the prognosis: those who emerged from a minimally conscious state (recovery group, n = 4) and those who remained in the unconscious state (unrecovery group, n = 5). Two rs-fMRI scans were obtained from all patients, and the second scan of patients in the recovery group was obtained after they regained consciousness. We performed seed-based fMRI analysis and selected the left ventral agranular insula (vAI) and dorsal agranular insula (dAI) as the regions of interest. Correlations with CRS-R were determined with the Spearman's correlation coefficient.Results: Compared with healthy controls, the functional connectivity between dAI and gyrus rectus of patients who recovered was significantly increased (p < 0.001, cluster-wise family-wise error rate [FWER] < 0.05). The second rs-fMRI scan of patients who remained with DOC showed a significant decreased functional connectivity between the dAI to contralateral insula, pallidum, bilateral inferior parietal lobule (IPL), precentral gyrus, and middle cingulate cortex (p < 0.001, cluster-wise FWER < 0.05) as well as the functional connectivity between vAI to caudate and cingulum contrast to controls (p < 0.001, cluster-wise FWER < 0.05). Finally, the functional connectivity strength of dAI-temporal pole (Spearman r = 0.491, p < 0.05) and dAI-IPL (Spearman r = 0.579, p < 0.05) were positively correlated with CRS-R scores in all DOC patients. The connectivity of dAI-IPL was also positively correlated with clinical scores in the recovery group (Spearman r = 0.807, p < 0.05).Conclusions: Our findings indicate that the recovery of consciousness is associated with an increased connectivity of the dAI to IPL and temporal pole. This possibly highlights the role of the insula in human consciousness. Moreover, longitudinal variations in dAI-IPL and dAI-temporal pole connectivity may be potential hallmarks in the outcome prediction of DOC patients.

Moderating Effects of Harm Avoidance on Resting-State Functional Connectivity of the Anterior Insula.

As an index of behavioral inhibition and an individual’s propensity to avoid, rather than seek, potentially dangerous situations, harm avoidance has been linked to internalizing psychopathology. Altered connectivity within intrinsic functional neural networks (i.e., default mode [DMN], central executive [CEN] and salience networks [SN]) has been related to internalizing psychopathology; however, less is known about the effects of harm avoidance on functional connectivity within and between these networks. Importantly, harm avoidance may be distinguishable from trait anxiety and have clinical relevance as a risk factor for internalizing psychopathology. A sample of young adults (n = 99) completed a resting state functional magnetic resonance imaging (fMRI) scan and self-report measures of harm avoidance and trait anxiety. Whole brain seed-to-voxel and seed-to-network connectivity analyses were conducted using anterior insula seeds to examine associations between harm avoidance/trait anxiety and connectivity. After adjusting for sex and age, there was a significant negative effect of harm avoidance on connectivity between the anterior insula and clusters in the precuneus/posterior cingulate cortex (PCC) left superior/middle frontal gyrus, dorsal anterior cingulate cortex (dACC) and bilateral inferior parietal lobule (IPL)/angular gyrus. Seed-to-network analyses indicated a negative effect of harm avoidance on connectivity between the right anterior insula and anterior and posterior DMN. There were no effects of trait anxiety on functional connectivity of the anterior insula. Overall, the results indicate that individual differences in harm avoidance relate to disruptions in internetwork connectivity that may contribute to deficits in appropriately modulating attentional focus.

Recursive Partitioning Analysis of Fractional Low-Frequency Fluctuations in Narcolepsy With Cataplexy.

Objective: To identify narcolepsy related regional brain activity alterations compared with matched healthy controls. To determine whether these changes can be used to distinguish narcolepsy from healthy controls by recursive partitioning analysis (RPA) and receiver operating characteristic (ROC) curve analysis.Method: Fifty-one narcolepsy with cataplexy patients (26 adults and 25 juveniles) and sixty matched heathy controls (30 adults and 30 juveniles) were recruited. All subjects underwent a resting-state functional magnetic resonance imaging scan. Fractional low-frequency fluctuations (fALFF) was used to investigate narcolepsy induced regional brain activity alterations among adult and juveniles, respectively. Recursive partitioning analysis and Receiver operating curve analysis was used to seek the ability of fALFF values within brain regions in distinguishing narcolepsy from healthy controls.Results: Compared with healthy controls, both adult and juvenile narcolepsy had lower fALFF values in bilateral medial superior frontal gyrus, bilateral inferior parietal lobule and supra-marginal gyrus. Compared with healthy controls, both adult and juvenile narcolepsy had higher fALFF values in bilateral sensorimotor cortex and middle temporal gyrus. Also juvenile narcolepsy had higher fALFF in right putamen and right thalamus compared with healthy controls. Based on RPA and ROC curve analysis, in adult participants, fALFF differences in right medial superior frontal gyrus can discriminate narcolepsy from healthy controls with high degree of sensitivity (100%) and specificity (88.9%). In juvenile participants, fALFF differences in left superior frontal gyrus can discriminate narcolepsy from healthy controls with moderate degree of sensitivity (57.1%) and specificity (88.9%).Conclusion: Compared with healthy controls, both the adult and juvenile narcolepsy showed overlap brain regions in fALFF differences after case-control comparison. Furthermore, we propose that fALFF value can be a helpful imaging biomarker in distinguishing narcolepsy from healthy controls among both adults and juveniles.

Reduced cortical thickness in subjects at clinical high risk for psychosis and clinical attributes.

Although neuroanatomical abnormalities in subjects at clinical high risk for psychosis have been considered a putative biomarker of psychosis, relevance of cortical thickness alterations remains contested due to discrepant findings. Inconsistencies persist in Asian clinical high risk studies, despite their advantageous settings well-controlled for confounds. Attributes of cortical thickness alterations in clinical high risk subjects warrant further examination. We examined cortical thickness at the whole-brain level in 74 clinical high risk subjects and 34 demographically matched healthy controls recruited from Seoul Youth Clinic, South Korea. Clinical symptoms were assessed using the Scale of Prodromal Symptoms, and their associations with cortical thickness were explored using partial correlation analysis. Compared to healthy control, clinical high risk exhibited significant cortical thinning in bilateral prefrontal cortex and inferior parietal lobule clusters. Reduced thickness in the left prefrontal cortex cluster was associated with more severe Scale of Prodromal Symptoms general symptoms scores and the right inferior parietal lobule cluster with Scale of Prodromal Symptoms disorganization symptoms. Thickness deficits found in the present clinical high risk sample demonstrated a degree of consistency with those reported in the previous Seoul Youth Clinic study. While inconsistencies reported between the present and previous Seoul Youth Clinic samples may reflect markedly decreased rate of converters, consistencies may be relevant to clinical attributes beyond transition, such as the prevalence of comorbidities. Particular recruitment strategies employed for sample selections should also be considered for findings in Asian clinical high risk samples. Our results suggest potential utility of cortical thickness alterations in clinical high risk subjects beyond the frame of transition.

Abnormal phasic activity in saliency network, motor areas, and basal ganglia in Parkinson's disease during rhythm perception.

Behavioral studies indicate that persons with Parkinson's disease have complexity dependent problems with the discrimination of auditory rhythms. Furthermore, neuroimaging studies show that rhythm processing activates many brain areas that overlap with areas affected by Parkinson's disease (PD). This study sought to investigate the neural correlates of rhythm processing in PD and healthy controls, with a particular focus on rhythmic complexity. We further aimed to investigate differences in brain activation during initial phases of rhythm processing. Functional magnetic resonance imaging was used to scan 15 persons with Parkinson's disease and 15 healthy controls while they listened to musical rhythms with two different levels of complexity. Rhythmic complexity had no significant effect on brain activations, but patients and controls showed differences in areas related to temporal auditory processing, notably bilateral planum temporale and inferior parietal lobule. We found indications of a particular sequential or phasic activation pattern of brain activity, where activity in caudate nucleus in the basal ganglia was time‐displaced by activation in the saliency network—comprised of anterior cingulate cortex and bilateral anterior insula—and cortical and subcortical motor areas, during the initial phases of listening to rhythms. We relate our findings to core PD pathology, and discuss the overall, rhythm processing related hyperactivity in PD as a possible dysfunction in specific basal ganglia mechanisms, and the phasic activation pattern in PD as a reflection of a lack of preparatory activation of task‐relevant brain networks for rhythm processing in PD.

Gray Matter Atrophy Is Associated With Cognitive Impairment in Patients With Presbycusis: A Comprehensive Morphometric Study.

Presbycusis (PC) is characterized by bilateral sensorineural hearing loss at high frequencies and speech-perception difficulties in noisy environments and has a strikingly detrimental impact on cognitive function. As the neural consequences of PC may involve the whole brain, we hypothesized that patients with PC would show structural alterations not only in the auditory cortex but also in the cortexes involved in cognitive function. The purpose of this study was to use surface-based morphometry (SBM) analysis to elucidate whole-brain structural differences between patients with PC and age-matched normal hearing controls. Three-dimensional T1-weighted MR images of 26 patients with mild PC and 26 age-, sex- and education-matched healthy controls (HCs) were acquired. All participants underwent a battery of neuropsychological tests. Our results revealed gray matter atrophy in several auditory cortical areas, nodes of the default mode network (DMN), including the bilateral precuneus and inferior parietal lobule, the right posterior cingulate cortex (PCC), and the right insula of patients with PC compared to that in the HCs. Our findings also revealed that hearing loss was associated with reduced gray matter volume in the right primary auditory cortex of patients with PC. Moreover, structural alterations in the nodes of the DMN were associated with cognitive impairments in PC patients. Additionally, this study provides evidence that a thicker right insula is associated with better speech perception in patients with PC. Based on these findings, we argue that the onset of PC seems to trigger its own cascade of conditions, including a need for increased cognitive resources during speech comprehension, which might lead to auditory and cognition-related cortical reorganization.