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A working hypothesis visualization method for fNIRS measurements using Monte Carlo simulation. MethodsX 2023; 11:102357. [PMID: 37727580 PMCID: PMC10506050 DOI: 10.1016/j.mex.2023.102357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 08/30/2023] [Indexed: 09/21/2023] Open
Abstract
In neuroscience, clarifying the functional localization of the cerebrum using functional near-infrared spectroscopy (fNIRS) is one of the important works. To better understand and trust fNIRS data, neuroscientists formulate hypothesis about the underlying neural processes. However, visualizing and validating these hypotheses is not easy due to the complex nature of brain activity and the limitations of fNIRS measurements. In this paper, we suggest the novel Monte Carlo tool designed to assist fNIRS study for neuroscientists and to deal with these problems. The tool provides a user-friendly interface for generating realistic virtual brain activity patterns based on a specified hypothesis. By setting up a region of interest in the standard brain based on the hypothesis, the simulation models the propagation of light through the brain accurately and mimics the hemodynamic response observed in fNIRS measurements. By visually displaying simulation data and identifying the major activation point, neuroscientists can validate and refine hypothesis and obtain a better understanding of the neural mechanisms underlying the fNIRS signals.•A Monte Carlo simulation method reflecting the functional localization of the cerebrum for fNIRS measurements.•Method for setting ROI corresponding to the functional localization of the cerebrum in the standard brain.•Visualization of Monte Carlo simulation results and anatomical evaluation method of activation points.
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EEG Connectivity in ADHD Compared to a Normative Database: A Cohort Analysis of 120 Subjects from the ICAN Study. Appl Psychophysiol Biofeedback 2023; 48:191-206. [PMID: 36469170 DOI: 10.1007/s10484-022-09569-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2022] [Indexed: 12/12/2022]
Abstract
This study explores how EEG connectivity measures in children with ADHD ages 7-10 (n = 140) differ from an age-matched nonclinical database. We differentiated connectivity in networks, Brodmann area pairs, and frequencies. Subjects were in the International Collaborative ADHD Neurofeedback study, which explored neurofeedback for ADHD. Inclusion criteria were mainly rigorously diagnosed ADHD and a theta/beta power ratio (TBR) ≤ 4.5. Using statistical and machine learning algorithms, connectivity values were extracted in coherence, phase, and lag coherence at all Brodmann, subcortical, and cerebellar areas within the main networks in all EEG frequencies and then compared with a normative database. There is a higher rate of dysregulation (more than ± 1.97SD), in some cases as much as 75%, of the Brodmann pairs observed in coherence and phase between BAs 7, 10, and 11 with secondary connections from these areas to BAs 21, 30, 35, 37, 39, and 40 in the ADHD children as compared to the normative database. Left and right Brodmann areas 10 and 11 are highly disconnected to each other. The most dysregulated Brodmann Areas in ADHD are 7, 10, and 11, relevant to ADHD executive-function deficits and provide important considerations when developing interventions for ADHD children.
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A Global Multiregional Proteomic Map of the Human Cerebral Cortex. GENOMICS, PROTEOMICS & BIOINFORMATICS 2022; 20:614-632. [PMID: 34763096 PMCID: PMC9880820 DOI: 10.1016/j.gpb.2021.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 06/25/2021] [Accepted: 09/27/2021] [Indexed: 01/31/2023]
Abstract
The Brodmann area (BA)-based map is one of the most widely used cortical maps for studies of human brain functions and in clinical practice; however, the molecular architecture of BAs remains unknown. The present study provided a global multiregional proteomic map of the human cerebral cortex by analyzing 29 BAs. These 29 BAs were grouped into 6 clusters based on similarities in proteomic patterns: the motor and sensory cluster, vision cluster, auditory and Broca's area cluster, Wernicke's area cluster, cingulate cortex cluster, and heterogeneous function cluster. We identified 474 cluster-specific and 134 BA-specific signature proteins whose functions are closely associated with specialized functions and disease vulnerability of the corresponding cluster or BA. The findings of the present study could provide explanations for the functional connections between the anterior cingulate cortex and sensorimotor cortex and for anxiety-related function in the sensorimotor cortex. The brain transcriptome and proteome comparison indicates that they both could reflect the function of cerebral cortex, but show different characteristics. These proteomic data are publicly available at the Human Brain Proteome Atlas (www.brain-omics.com). Our results may enhance our understanding of the molecular basis of brain functions and provide an important resource to support human brain research.
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Reduced Resting-State Cortical Alpha Connectivity Reflects Distinct Functional Brain Dysconnectivity in Alzheimer's Disease and Mild Cognitive Impairment. Brain Connect 2021; 12:134-145. [PMID: 34030487 DOI: 10.1089/brain.2020.0926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Emerging evidence suggests distinct abnormal activity patterns during resting state in intrinsic functional brain networks in patients with neurodegenerative diseases, including Alzheimer's disease (AD) and mild cognitive impairment (MCI). This study aimed to identify the changes in the resting-state intracortical lagged phase synchronization derived from dense array electroencephalography (EEG) in AD and MCI. Methods: Resting-state current source density (CSD) and lagged phase synchronization between 84 regions of interest defined by Brodmann areas (BAs) for seven EEG frequency bands were investigated between the study groups (AD, MCI, and age-matched controls) using 128-channel EEG. Results: Reduced CSD and connectivity (large effect size, Cohen's d > 0.8) were found in AD and MCI compared with controls at alpha frequency. However, a positive correlation (r = 0.433; p = 0.044) of mini-mental state examination scores was found with BA 32-33 connectivity values in AD only. Conclusion: Reduced resting-state alpha 1 source connectivity in patient groups and correlation between attenuation of resting-state alpha 1 connectivity with cognitive decline in AD could indicate the disruption of inhibitory function of alpha rhythm leading to tonic unselective cortical excitation that affects attention and controlled access to stored information.
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Functional organization of the human primary somatosensory cortex: A stereo-electroencephalography study. Clin Neurophysiol 2021; 132:487-497. [PMID: 33465535 DOI: 10.1016/j.clinph.2020.11.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/31/2020] [Accepted: 11/24/2020] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The classical homunculus of the human primary somatosensory cortex (S1) established by Penfield has mainly portrayed the functional organization of convexial cortex, namely Brodmann area (BA) 1. However, little is known about the functions in fissural cortex including BA2 and BA3. We aim at drawing a refined and detailed somatosensory homunculus of the entire S1. METHODS We recruited 20 patients with drug-resistant focal epilepsy who underwent stereo-electroencephalography for preoperative assessments. Direct electrical stimulation was performed for functional mapping. Montreal Neurological Institute coordinates of the stimulation sites lying in S1 were acquired. RESULTS Stimulation of 177 sites in S1 yielded 149 positive sites (84%), most of which were located in the sulcal cortex. The spatial distribution of different body-part representations across the S1 surface revealed that the gross medial-to-lateral sequence of body representations within the entire S1 was consistent with the classical "homunculus". And we identified several unreported body-part representations from the sulcal cortex, such as forehead, deep elbow and wrist joints, and some dorsal body regions. CONCLUSIONS Our results reveal general somatotopical characteristics of the entire S1 cortex and differences with the previous works of Penfield. SIGNIFICANCE The classical S1 homunculus was extended by providing further refinement and additional detail.
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A Protocol for Cortical Type Analysis of the Human Neocortex Applied on Histological Samples, the Atlas of Von Economo and Koskinas, and Magnetic Resonance Imaging. Front Neuroanat 2020; 14:576015. [PMID: 33364924 PMCID: PMC7750391 DOI: 10.3389/fnana.2020.576015] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 11/05/2020] [Indexed: 12/15/2022] Open
Abstract
The human cerebral cortex is parcellated in hundreds of areas using neuroanatomy and imaging methods. Alternatively, cortical areas can be classified into few cortical types according to their degree of laminar differentiation. Cortical type analysis is based on the gradual and systematic variation of laminar features observed across the entire cerebral cortex in Nissl stained sections and has profound implications for understanding fundamental aspects of evolution, development, connections, function, and pathology of the cerebral cortex. In this protocol paper, we explain the general principles of cortical type analysis and provide tables with the fundamental features of laminar structure that are studied for this analysis. We apply cortical type analysis to the micrographs of the Atlas of the human cerebral cortex of von Economo and Koskinas and provide tables and maps with the areas of this Atlas and their corresponding cortical type. Finally, we correlate the cortical type maps with the T1w/T2w ratio from widely used reference magnetic resonance imaging scans. The analysis, tables and maps of the human cerebral cortex shown in this protocol paper can be used to predict patterns of connections between areas according to the principles of the Structural Model and determine their level in cortical hierarchies. Cortical types can also predict the spreading of abnormal proteins in neurodegenerative diseases to the level of cortical layers. In summary, cortical type analysis provides a theoretical and practical framework for directed studies of connectivity, synaptic plasticity, and selective vulnerability to neurologic and psychiatric diseases in the human neocortex.
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The Neurosciences of Health Communication: An fNIRS Analysis of Prefrontal Cortex and Porn Consumption in Young Women for the Development of Prevention Health Programs. Front Psychol 2020; 11:2132. [PMID: 32982871 PMCID: PMC7488514 DOI: 10.3389/fpsyg.2020.02132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 07/30/2020] [Indexed: 12/30/2022] Open
Abstract
This work explores the use of fNIRS neuroimaging technique using young female college students with different levels of consumption of pornography, and the activation of the prefrontal cortex (cue reactivity) when viewing a pornographic clip (cue exposure) versus a control clip. The results indicate that the viewing of the pornographic clip (vs. control clip) causes an activation of Brodmann's area 45 of the right hemisphere (BA 45, pars triangularis) (p < 0.01). An effect also appears between the level of self-reported consumption and the activation of right BA 45: the higher the level of self-reported consumption, the greater the activation (p < 0.01). On the other hand, those participants who have never consumed pornographic material do not show activity of the right BA 45 compared to the control clip (p < 0.01) indicating a qualitative difference between non-consumers and consumers. These results are consistent with other research made in the field of addictions. It is hypothesized that the mirror neuron system may be involved, through the mechanism of empathy, which could provoke vicarious eroticism. Finally, we suggest the applications that these results may have for primary and secondary prevention programs in the field of problematic consumption of pornography.
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Abstract
Schizophrenia (SCZ) is characterized by abnormal thoughts, behaviors and speech, along with a decreased perception of reality that can included visual or auditory hallucinations, withdrawal of social activity and lack of motivation, etc. Many hypotheses related to the causes of SCZ have been proposed, but the underlying neuropathological mechanism remains unclear. Recent studies have suggested that there is an association between autophagy and SCZ. The strongest evidence for this comes from the expression of ATGs in the BA22 of postmortem samples from SCZ patients, coinciding with some of the brain imaging studies and certain hypotheses about SCZ in interpreting the positive symptoms. Autophagy dysfunction in the hippocampus, especially in the CA2 region, may relate to deficits of social communication and interaction in SCZ patients. mTOR regulation of autophagy is also potentially a piece of strong supporting evidence for the autophagic neuropathogenesis of SCZ. In vitro studies show that antipsychotics often induce autophagy through distinct mechanisms of drug action, but they may all share common features as autophagy inducers and antagonists of dopamine receptors.
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Copula directional dependence for inference and statistical analysis of whole-brain connectivity from fMRI data. Brain Behav 2019; 9:e01191. [PMID: 30592175 PMCID: PMC6346668 DOI: 10.1002/brb3.1191] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 11/22/2018] [Accepted: 11/29/2018] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION Inferring connectivity between brain regions has been raising a lot of attention in recent decades. Copula directional dependence (CDD) is a statistical measure of directed connectivity, which does not require strict assumptions on probability distributions and linearity. METHODS In this work, CDDs between pairs of local brain areas were estimated based on the fMRI responses of human participants watching a Pixar animation movie. A directed connectivity map of fourteen predefined local areas was obtained for each participant, where the network structure was determined by the strengths of the CDDs. A resampling technique was further applied to determine the statistical significance of the connectivity directions in the networks. In order to demonstrate the effectiveness of the suggested method using CDDs, statistical group analysis was conducted based on graph theoretic measures of the inferred directed networks and CDD intensities. When the 129 fMRI participants were grouped by their age (3-5 year-old, 7-12 year-old, adult) and gender (F, M), nonparametric two-way analysis of variance (ANOVA) results could identify which cortical regions and connectivity structures correlated with the two physiological factors. RESULTS Especially, we could identify that (a) graph centrality measures of the frontal eye fields (FEF), the inferior temporal gyrus (ITG), and the temporopolar area (TP) were significantly affected by aging, (b) CDD intensities between FEF and the primary motor cortex (M1) and between ITG and TP were highly significantly affected by aging, and (c) CDDs between M1 and the anterior prefrontal cortex (aPFC) were highly significantly affected by gender. SOFTWARE The R source code for fMRI data preprocessing, estimation of directional dependences, network visualization, and statistical analyses are available at https://github.com/namgillee/CDDforFMRI.
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Abstract
D-serine is an endogenous ligand for N-methyl-D-aspartate glutamate receptors. Accumulating evidence including genetic associations of D-serine metabolism with neurological or psychiatric diseases suggest that D-serine is crucial in human neurophysiology. However, distribution and regulation of D-serine in humans are not well understood. Here, we found that D-serine is heterogeneously distributed in the human central nervous system (CNS). The cerebrum contains the highest level of D-serine among the areas in the CNS. There is heterogeneity in its distribution in the cerebrum and even within the cerebral neocortex. The neocortical heterogeneity is associated with Brodmann or functional areas but is unrelated to basic patterns of cortical layer structure or regional expressional variation of metabolic enzymes for D-serine. Such D-serine distribution may reflect functional diversity of glutamatergic neurons in the human CNS, which may serve as a basis for clinical and pharmacological studies on D-serine modulation.
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Cortical and subcortical functional neuroanatomy for low-grade glioma surgery. Neurochirurgie 2017; 63:117-121. [PMID: 28506483 DOI: 10.1016/j.neuchi.2016.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 08/22/2016] [Accepted: 10/23/2016] [Indexed: 11/22/2022]
Abstract
Knowledge of the encephalon anatomy is crucial for neurosurgical practice, especially the main cortical functional structures and their connections. General organisation of the encephalon is presented with frontal, parietal, occipital, temporal, limbic and insular lobes and their Brodmann correspondence. Secondly, subcortical anatomy will be presented with main white matter fasciculi in three separated categories: association, commissural and projection fibers. Main association fibers are inferior occipitofrontal fasciculus, superior longitudinal fasciculus, arcuate fasciculus, inferior longitudinal fasciculus, uncinate fasciculus, and cingulum. Commissural fibers include anterior commissure, corpus callosum and fornix. Projection fibers are internal capsule and optic radiations.
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A functional magnetic resonance imaging investigation of visual hallucinations in the human striate cortex. Behav Brain Funct 2016; 12:31. [PMID: 27899123 PMCID: PMC5126868 DOI: 10.1186/s12993-016-0115-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/22/2016] [Indexed: 11/17/2022] Open
Abstract
Purpose Human beings frequently experience fear, phobia, migraine and hallucinations, however, the cerebral mechanisms underpinning these conditions remain poorly understood. Towards this goal, in this work, we aim to correlate the human ocular perceptions with visual hallucinations, and map them to their cerebral origins. Methods An fMRI study was performed to examine the visual cortical areas including the striate, parastriate and peristriate cortex in the occipital lobe of the human brain. 24 healthy subjects were enrolled and four visual patterns including hallucination circle (HCC), hallucination fan (HCF), retinotopy circle (RTC) and retinotopy cross (RTX) were used towards registering their impact in the aforementioned visual related areas. One-way analysis of variance was used to evaluate the significance of difference between induced activations. Multinomial regression and and K-means were used to cluster activation patterns in visual areas of the brain. Results Significant activations were observed in the visual cortex as a result of stimulus presentation. The responses induced by visual stimuli were resolved to Brodmann areas 17, 18 and 19. Activation data clustered into independent and mutually exclusive clusters with HCC registering higher activations as compared to HCF, RTC and RTX. Conclusions We conclude that small circular objects, in rotation, tend to leave greater hallucinating impressions in the visual region. The similarity between observed activation patterns and those reported in conditions such as epilepsy and visual hallucinations can help elucidate the cortical mechanisms underlying these conditions. Trial Registration 1121_GWJUNG
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Acupuncture for ischemic stroke: cerebellar activation may be a central mechanism following Deqi. Neural Regen Res 2016; 10:1997-2003. [PMID: 26889189 PMCID: PMC4730825 DOI: 10.4103/1673-5374.172318] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The needling sensation of Deqi during acupuncture is a key factor of influencing acupuncture outcome. Recent studies have mainly focused on the brain function effects of Deqi in a physiological state. Functional magnetic resonance imaging (fMRI) on the effects of acupuncture at Waiguan (SJ5) in pathological and physiological states is controversial. In this study, 12 patients with ischemic stroke received acupuncture at Waiguan (SJ5) and simultaneously underwent fMRI scanning of the brain, with imaging data of the activated areas obtained. Based on the patient's sensation, imaging data were allocated to either the Deqi group or non-Deqi group. In the Deqi group, the activated/deactivated areas were the left superior temporal gyrus (BA39)/right anterior lobe of the cerebellum and left thalamus. In the non-Deqi group, the activated areas included the medial frontal gyrus of the right frontal lobe (BA11), right limbic lobe (BA30, 35), and left frontal lobe (BA47), while the only deactivated area was the right parietal lobe (BA40). Compared with the non-Deqi group, the Deqi group exhibited marked activation of the right anterior lobe of the cerebellum and right limbic lobe (BA30). These findings confirm that the clinical effect of Deqi during acupuncture is based on brain functional changes. Cerebellar activation may be one of the central mechanisms of acupuncture in the treatment of ischemic stroke.
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Acupuncture at Waiguan (SJ5) and sham points influences activation of functional brain areas of ischemic stroke patients: a functional magnetic resonance imaging study. Neural Regen Res 2014; 9:293-300. [PMID: 25206815 PMCID: PMC4146151 DOI: 10.4103/1673-5374.128227] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2013] [Indexed: 11/22/2022] Open
Abstract
Most studies addressing the specificity of meridians and acupuncture points have focused mainly on the different neural effects of acupuncture at different points in healthy individuals. This study examined the effects of acupuncture on brain function in a pathological context. Sixteen patients with ischemic stroke were randomly assigned to true point group (true acupuncture at right Waiguan (SJ5)) and sham point group (sham acupuncture). Results of functional magnetic resonance imaging revealed activation in right parietal lobe (Brodmann areas 7 and 19), the right temporal lobe (Brodmann area 39), the right limbic lobe (Brodmann area 23) and bilateral occipital lobes (Brodmann area 18). Furthermore, inhibition of bilateral frontal lobes (Brodmann area 4, 6, and 45), right parietal lobe (Brodmann areas 1 and 5) and left temporal lobe (Brodmann area 21) were observed in the true point group. Activation in the precuneus of right parietal lobe (Brodmann area 7) and inhibition of the left superior frontal gyrus (Brodmann area 10) was observed in the sham group. Compared with sham acupuncture, acupuncture at Waiguan in stroke patients inhibited Brodmann area 5 on the healthy side. Results indicated that the altered specificity of sensation-associated cortex (Brodmann area 5) is possibly associated with a central mechanism of acupuncture at Waiguan for stroke patients.
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Self vs. other: neural correlates underlying agent identification based on unimodal auditory information as revealed by electrotomography (sLORETA). Neuroscience 2013; 259:25-34. [PMID: 24295635 DOI: 10.1016/j.neuroscience.2013.11.042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 11/21/2013] [Accepted: 11/21/2013] [Indexed: 11/23/2022]
Abstract
Recent neuroscientific studies have identified activity changes in an extensive cerebral network consisting of medial prefrontal cortex, precuneus, temporo-parietal junction, and temporal pole during the perception and identification of self- and other-generated stimuli. Because this network is supposed to be engaged in tasks which require agent identification, it has been labeled the evaluation network (e-network). The present study used self- versus other-generated movement sounds (long jumps) and electroencephalography (EEG) in order to unravel the neural dynamics of agent identification for complex auditory information. Participants (N=14) performed an auditory self-other identification task with EEG. Data was then subjected to a subsequent standardized low-resolution brain electromagnetic tomography (sLORETA) analysis (source localization analysis). Differences between conditions were assessed using t-statistics (corrected for multiple testing) on the normalized and log-transformed current density values of the sLORETA images. Three-dimensional sLORETA source localization analysis revealed cortical activations in brain regions mostly associated with the e-network, especially in the medial prefrontal cortex (bilaterally in the alpha-1-band and right-lateralized in the gamma-band) and the temporo-parietal junction (right hemisphere in the alpha-1-band). Taken together, the findings are partly consistent with previous functional neuroimaging studies investigating unimodal visual or multimodal agent identification tasks (cf. e-network) and extent them to the auditory domain. Cortical activations in brain regions of the e-network seem to have functional relevance, especially the significantly higher cortical activation in the right medial prefrontal cortex.
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Premenstrual dysphoric disorder and prefrontal reactivity during anticipation of emotional stimuli. Eur Neuropsychopharmacol 2013; 23:1474-83. [PMID: 24001875 DOI: 10.1016/j.euroneuro.2013.08.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 07/06/2013] [Accepted: 08/11/2013] [Indexed: 11/20/2022]
Abstract
Premenstrual disorder (PMDD) affects around 5% of women in childbearing ages. An increased sensitivity in emotion processing areas of the brain to variations in ovarian steroid levels has been suggested as part of the pathophysiology in PMDD, but prior neuroimaging studies of emotion processing are yet inconclusive. Previous behavioral studies of women with PMDD have, however, reported enhanced luteal phase startle responsivity during emotional anticipation. Here we used functional magnetic resonance imaging (fMRI) to investigate central neural circuitry activity during anticipation of, and exposure to, emotional stimuli across the menstrual cycle in women with and without PMDD. As compared to healthy controls, women with PMDD displayed significantly enhanced reactivity in the prefrontal cortex during anticipation of, but not exposure to, negative emotional stimuli during the luteal phase. In PMDD patients, BOLD reactivity during anticipation or viewing of negative emotional stimuli was not dependent on absolute levels of estradiol or progesterone. However, progesterone levels were positively correlated with emotion-induced reactivity in the dorsolateral prefrontal cortex to positive emotional stimuli. These findings suggest that cortical emotional circuitry reactivity during anticipation is altered in PMDD during the luteal phase, which might be part of the pathophysiology behind the emotional symptoms or lack of emotional control reported by women with PMDD.
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Neural correlates of dysfunctional emotion regulation in major depressive disorder. A systematic review of neuroimaging studies. Neurosci Biobehav Rev 2013; 37:2529-53. [PMID: 23928089 DOI: 10.1016/j.neubiorev.2013.07.018] [Citation(s) in RCA: 317] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 06/25/2013] [Accepted: 07/27/2013] [Indexed: 11/16/2022]
Abstract
Abnormal emotion processing is a core feature of major depressive disorder (MDD). Since the emergence of functional neuroimaging techniques, many studies have been conducted in MDD subjects to elucidate the underlying abnormalities in the neural systems involved in emotion regulation. In this systematic review, we discuss this research in the context of the neural model of emotion regulation previously described by Phillips et al. (2008). This model differentiates between automatic and voluntary emotion regulation subprocesses. Automatic regulation subprocesses were shown to involve predominantly medial prefrontal cortical structures, in addition to the hippocampus and parahippocampus, while voluntary regulation processes additionally recruited lateral prefrontal cortical regions. In conclusion, although the available data is limited, findings suggest that MDD subjects demonstrate abnormally reduced activity in lateral prefrontal cortices during explicit voluntary control of emotional experience. During early, automatic stages of emotion regulation, on the other hand, MDD subjects appear to achieve successful emotion regulation by recruiting additional lateral prefrontal neural regions, that may be mediated by medial prefrontal, especially rostral/dorsal anterior cingulate gyrus (ACG) functioning. Dysfunctional automatic regulation may impair successful voluntary emotion regulation, and may present a target for novel therapeutic approaches in MDD.
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Over-activation in bilateral superior temporal gyrus correlated with subsequent forgetting effect of Chinese words. BRAIN AND LANGUAGE 2013; 126:203-207. [PMID: 23796961 DOI: 10.1016/j.bandl.2013.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 05/20/2013] [Accepted: 05/20/2013] [Indexed: 06/02/2023]
Abstract
We evaluated the subsequent memory and forgotten effects for Chinese using event-related fMRI. Sixteen normal subjects were recruited and performing incidental memory tasks where semantic decision was required during memory encoding. Consistent with previous studies, our results showed bilateral frontal regions as the main locus for the subsequent memory effect. However, contrast between miss and hit responses revealed larger activation in bilateral superior temporal gyrus. We proposed that larger activation in the superior temporal gyrus may reflect alteration of self-monitoring process which resulted in unsuccessful memory encoding for the miss items.
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Callosal degeneration topographically correlated with cognitive function in amnestic mild cognitive impairment and Alzheimer's disease dementia. Hum Brain Mapp 2013; 35:1529-43. [PMID: 23670960 DOI: 10.1002/hbm.22271] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 09/30/2012] [Accepted: 01/17/2012] [Indexed: 11/09/2022] Open
Abstract
Degeneration of the corpus callosum (CC) is evident in the pathogenesis of Alzheimer's disease (AD). However, the correlation of microstructural damage in the CC on the cognitive performance of patients with amnestic mild cognitive impairment (aMCI) and AD dementia is undetermined. We enrolled 26 normal controls, 24 patients with AD dementia, and 40 single-domain aMCI patients with at least grade 1 hippocampal atrophy and isolated memory impairment. Diffusion tensor imaging (DTI) with fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (DA), and radial diffusivity (DR) were measured. The entire CC was parcellated based on fiber trajectories to specific cortical Brodmann areas using a probabilistic tractography method. The relationship between the DTI measures in the subregions of the CC and cognitive performance was examined. Although the callosal degeneration in the patients with aMCI was less extended than in the patients with AD dementia, degeneration was already exhibited in several subregions of the CC at the aMCI stage. Scores of various neuropsychological tests were correlated to the severity of microstructural changes in the subregional CC connecting to functionally corresponding cortical regions. Our results confirm that CC degeneration is noticeable as early as the aMCI stage of AD and the disconnection of the CC subregional fibers to the corresponding Brodmann areas has an apparent impact on the related cognitive performance.
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Increased SMA-M1 coherence in Parkinson's disease - Pathophysiology or compensation? Exp Neurol 2013; 247:178-81. [PMID: 23664959 DOI: 10.1016/j.expneurol.2013.04.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 04/10/2013] [Accepted: 04/25/2013] [Indexed: 11/28/2022]
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder owing to loss of dopaminergic cells. Akinesia - one of the core symptoms of PD - is associated with exaggerated oscillations at beta frequency (13-30 Hz) within the subthalamic nucleus (STN). Thus, enhanced oscillations below 30 Hz are assumed to represent a pathophysiological marker of PD. However, recent data suggest that OFF medication exaggerated beta oscillations within basal ganglia (BG) cortical networks may serve for the compensation of BG dysfunctions. The STN is functionally connected to mesial prefrontal areas like the supplementary motor area (SMA). But, it is still not fully understood how enhanced beta oscillations within the BG exert dominance over the primary motor cortex (M1) thereby yielding motor impairment. The present study, therefore, investigates the effect of dopaminergic state on SMA-M1 functional connectivity using Magnetoencephalography (MEG). MEG data were recorded in 7 patients suffering from PD with preponderance of akinesia during isometric contraction of the right forearm and during rest. Coherence as a measure of functional connectivity between M1 and SMA was calculated OFF and ON medication and correlated with the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS III) and with disease duration. During rest a significant positive correlation between disease duration and SMA-M1 coherence was found ON but not OFF medication. Conversely, during isometric contraction SMA-M1 coherence and UPDRS III were inversely correlated OFF but not ON medication explaining more than 80% of variance. The results favor the hypothesis that OFF medication exaggerated cortical coherence at beta frequency represents a compensatory mechanism rather than a pathophysiological marker per se.
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Practical considerations in the development and refinement of subcallosal cingulate white matter deep brain stimulation for treatment-resistant depression. World Neurosurg 2012; 80:S27.e25-34. [PMID: 23246630 DOI: 10.1016/j.wneu.2012.11.074] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 11/12/2012] [Accepted: 11/27/2012] [Indexed: 12/28/2022]
Abstract
BACKGROUND Deep brain stimulation has been investigated in the past decade as a viable intervention for treatment-resistant depression. METHODS Several anatomic targets have been tested, with the most extensive published experience found for the subcallosal cingulate (SCC) white matter. RESULTS This article reviews the current state of clinical research of SCC deep brain stimulation for treatment-resistant depression, including an overview of the rationale for targeting SCC, practical considerations for subject recruitment and evaluation, surgical planning, and stimulation parameters. CONCLUSION Clinical management of patients in the initial and long-term naturalistic phases of treatment, including the potential role for psychotherapeutic rehabilitation, is discussed.
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