Preserved functional specialization for spatial processing in the middle occipital gyrus of the early blind

Attention Performance and Altered Amplitude of Low-frequency Fluctuations in the Attention Network of Patients with MCI: A Resting-state Functional MRI Study

BACKGROUND

This study aimed to explore attention alteration in mild cognitive impairment (MCI) patients and their association with abnormalities of autonomic brain activity within the attention network to reveal the neuroimaging basis behind these changes.

METHODS

A total of 25 MCI patients and 31 normal controls (NCs) were recruited for the study. The Test of Attention Performance (TAP) version 2.3 was used to evaluate alertness, selective attention, and divided attention in MCI patients and NCs. Subsequently, participants underwent resting-state magnetic resonance imaging (MRI) scans to compare whole-brain autonomic activity characteristics between groups using the amplitude of low-frequency fluctuation (ALFF). Data preprocessing and analysis were conducted using Data Processing & Analysis of Brain Imaging in MATLAB R2018b.

RESULTS

There were significant differences in omissions of intrinsic alertness, total omissions of divided attention, omissions and correct of visual divided attention between the two groups. Meanwhile, independent sample t-tests indicated that the MCI group exhibited higher z-scored ALFF (zALFF) in the left middle occipital gyrus, left superior frontal gyrus (orbital part), and right inferior frontal gyrus (orbital part) when compared with the NC group. The MCI group exhibited reduced zALFF in the left median cingulate and paracingulate gyrus, left precuneus, and right rolandic operculum. Notably, the decreased zALFF in the left precuneus showed a significant negative correlation with divided attention.

CONCLUSIONS

Our findings suggest that patients with MCI exhibit relatively normal performance in selective attention and phase alertness tasks, while they demonstrate a decline in capacity for divided attention and intrinsic alertness tasks. Divided attention in MCI patients may be associated with abnormalities in spontaneous neural activity in the left precuneus. This study provides new and complementary insights into the neural basis of divided attention in patients with MCI.

The possible effect of inflammation on non-suicidal self-injury in adolescents with depression: a mediator of connectivity within corticostriatal reward circuitry

Non-suicidal self-injury (NSSI) in adolescent depression is a prevalent and clinically significant behavior linked to dysregulated peripheral inflammation and corticostriatal circuitry dysfunction. However, the neuroimmune mechanisms bridging these systems remain poorly understood. Here, we combined peripheral cytokine profiling with static/dynamic functional connectivity (sFC/dFC) analysis to investigate the potential influence of inflammaton on corticostriatal circuit related to NSSI. A set of peripheral blood inflammatory markers and resting-state functional magnetic resonance imaging (rs-fMRI) were collected in depression with NSSI (NSSI+), depression without NSSI (NSSI-), and healthy controls (HC). We first ascertain group differences in level of pro- and anti-inflammatory cytokines. And using ventral/dorsal striatal seeds, we compared whole-brain, voxel-wise sFC and dFC differences across three groups. Further, we tested the mediation effects of connectivity in the association between inflammatory markers and NSSI frequency. NSSI+ group exhibited elevated pro-inflammatory cytokines (C-reactive protein (CRP), interleukin (IL)-1, and IL-6) whereas reduced anti-inflammatory cytokines (IL-10), compared to NSSI- and HC. Neuroimaging analysis revealed corticostriatal dysconnectivity mainly characterized by static hyperconnectivity between dorsal striatum and thalamus, dynamic instability in dorsal striatum-lingual pathways, and dynamic rigidity in ventral striatum-prefrontal/temporal/occipital gyrus circuits. Critically, sFC of dorsal striatum-thalamus and dFC of dorsal striatum-lingual gyrus mediated the prospective association between altered CRP and NSSI frequency, establishing corticostriatal circuits as conduits for inflammatory effects on NSSI. By bridging molecular psychiatry with circuit neuroscience, this work advances precision management of NSSI in adolescent depression, prioritizing biomarker-driven strategies to disrupt neuroimmune maladaptation.

The Default Mode Network and Visual Network Functional Connectivity Changes in Noise-Induced Hearing Loss Patients: A Resting-State fMRI Study

BACKGROUND

Hearing loss affects communication and hinders personal attention and cognitive ability. We hypothesized that noise-induced hearing loss (NIHL) patients during long-term noise exposure may result in multimodal plastic changes in the nonauditory central nervous system.

OBJECTIVE

To investigate the functional connectivity (FC) of the default mode network (DMN) and visual network (VN) in patients with occupational NIHL using resting-state functional magnetic resonance imaging (rs-fMRI).

METHODS

Ninety-eight people with NIHL and 78 healthy controls (HCs) matched for age and educational level were enrolled. The mini-mental state examination (MMSE) was conducted, and rs-fMRI scanning was performed. The data were processed and analyzed to identify FC changes between DMN, VN, and the whole brain.

RESULTS

Compared with the HCs, the NIHL group showed significantly enhanced connectivity with multiple brain regions when utilizing the DMN as seed regions of interest (ROI), with only some brain regions showing significantly decreased connectivity. When the VN was used as the seed ROI, the NIHL group showed significantly enhanced connectivity with multiple brain regions (corrected by GRF, p < 0.05). In the present study, the FC between multiple brain areas of VN and DMN in the NIHL patient group was enhanced compared to the normal population. The phenomenon of "perceptual compensation" is confirmed. The results of this study suggest that NIHL causes various changes in brain function related to emotion, decision-making, social cognition, and psychopathology. It suggests that changes in brain functional networks involve complex processes involving plasticity and damage to multiple networks.

CONCLUSIONS

The NIHL patients showed abnormal FC changes in both the DMN and VN, indicating widespread multimodal plasticity and reorganization of nonauditory central nervous system functions in people with NIHL.

Structure/function alterations and related neurotransmitter activity maps in high myopia patients

This study explored the relationship between brain structure and functional pattern as well as the potential neurotransmitter activity alterations in patients with high myopia (HM). Total 33 HM patients and 31 healthy controls were included. Gray matter volume (GMV) was employed to represent brain structure indicator, and amplitude of low-frequency fluctuations (ALFF) was used as an indicator of function. Use the data fusion method of parallel independent component analysis (ICA) to identify the independent components of two patterns and analyze the relationship between them. The spatial correlations between the altered ICA value and neurotransmitter maps were calculated. The results show that there is a significantly related sets of independent components (GMV_IC5 and ALFF_IC4) between the HM and healthy control groups in terms of structure and function. The structural components mainly include the temporal lobe, frontal lobe, cingulate gyrus, and occipital lobe; the functional components are primarily composed of the precuneus, occipital lobe, temporal lobe, and lingual Gyrus. The change value of GMV_IC5 is significantly correlated with serotonin 5-hydroxytryptamine receptor (subtype 1a, 1b and 2a), dopamine D1, gamma-aminobutyric acid (GABAa), and metabotropic glutamate receptor 5; while, the altered ALFF in ALFF_IC4 is significantly correlated with serotonin 5-hydroxytryptamine receptor subtype 2a, dopamine D1, and GABAa. Research results suggest the structural and functional components that change together reflect the association between the visual brain regions and the temporal-frontal areas in HM, as well as their correlation with serotonin receptors, dopamine, and the GABA neurotransmitter system.

Association of aberrant brain network connectivity with visual dysfunction in patients with nonarteritic anterior ischemic optic neuropathy: a pilot study

Background

Nonarteritic anterior ischemic optic neuropathy (NAION) is often accompanied by degeneration of optic nerve axons and ganglion cell apoptosis, but the mechanism of its effects on the cerebral cortex and visual centers is not clear. Graph theory analysis, as a quantitative tool for complex networks, has made it possible to characterize the topological alterations of brain networks in patients with NAION. The objective of this pilot study was to investigate the topological characteristics of functional brain networks in patients with NAION and to analyze their potential correlation with visual dysfunction.

Methods

This prospective, cross-sectional study recruited 25 patients with NAION and 24 matched healthy controls (HCs) from Dongfang Hospital, Beijing University of Chinese Medicine. Following resting-state functional magnetic resonance imaging (rs-fMRI) scans, large-scale functional connectivity matrices of 90 regions were constructed. Graph theory was then used to compare global and local network parameters. Subsequently, network-based statistics (NBS) analysis was employed to detect differences in functional connectivity across the brain. Finally, correlations were assessed between the network topological properties and clinical variables.

Results

Individuals with NAION, as compared to controls, exhibited significant decreases in normalized clustering coefficient (gamma; P=0.021), small-worldness (sigma; P=0.043), and local efficiency (Eloc; P=0.030), as well as a significant increase in the size of the largest connected component (LCC; P=0.039) of the network. Additionally, the LCC showed a negative association with gamma, sigma and global efficiency (Eg) but a positive correlation with the normalized characteristic path length (lambda) of the two groups (all P values <0.05). Regionally, patients exhibited changes in nodal centralities, particularly affecting the attention, visual, and salience networks. NBS analysis identified an interconnected subnetwork consisting of 49 nodes and 77 edges (P<0.001, NBS-corrected) that showed significantly higher connectivity in patients with NAION. The mean connectivity of this subnetwork was negatively correlated with the global topological parameters gamma, sigma, and Eg in the NAION group and gamma and sigma in the HCs but positively correlated with the LCC in both groups (all P values <0.05). Moreover, the nodal betweenness centrality of the left dorsolateral superior frontal gyrus exhibited a significant positive correlation with the visual field (VF) mean deviation (MD) in the NAION group (P<0.001).

Conclusions

This study initially identified aberrant topological and connectivity changes in the functional brain networks associated with visual impairment in patients with NAION, thus expanding our existing understanding of the neurobiological mechanisms of NAION.

Causality of brain region activation during driver takeover in conditional autonomous driving: a study based on fMRI experiments

OBJECTIVE

Understanding the neural decision-making mechanisms of drivers during takeover in conditional autonomous driving is crucial for improving driver safety and performance. This study investigates how visibility and urgency affect the activation and interactions of key brain regions, including the middle temporal gyrus (MTG), fusiform gyrus (FG), middle occipital gyrus (MOG), precentral gyrus (PCG), and precuneus (PCu), which are involved in distance perception, visual recognition, color processing, motor planning, and memory retrieval.

METHODS

Functional magnetic resonance imaging (fMRI) and Granger causality analysis were used to examine the brain activation patterns and interregional interactions of these areas during four driving scenarios, involving good or poor visibility and emergency or non-emergency conditions in a conditional autonomous driving context.

RESULTS

Under complex driving conditions (poor visibility or emergency), interactions among regions involved in visual processing and spatial cognition were significantly enhanced, reflecting the need for rapid integration of visual information. Both immediate and delayed effects were identified, with immediate responses prioritizing rapid perception and motor actions, while delayed effects supported sustained visual and spatial processing as conditions stabilized.

CONCLUSIONS

These findings provide insights into the neural mechanisms driving behavior under varying driving conditions, aiding the optimization of driver assistance systems (ADAS), enhancing semi-autonomous driving safety and performance, and informing the development of personalized driver support technologies.

Spatial and temporal patterns of brain neural activity mediating human thermal sensations

This study aimed to elucidate the spatial and temporal patterns of brain neural activity that are associated with cold and hot sensations. Participants (n = 20) sat in a controlled room with their eyes closed and received local thermal stimuli to the right fingers using a Peltier apparatus. The thermal stimuli were repeated 40 times using a paired-thermal stimulus paradigm, comprising a 15 s-reference stimulus (32 °C), followed by 10 s-conditioned stimuli (24 °C and 40 °C, cold and hot conditions, respectively), for which 15-channel electroencephalography (EEG) signals were continuously monitored. To identify the patterns of brain neural activity, an independent component (IC) analysis was applied to the preprocessed EEG data. The equivalent current dipole locations were estimated, followed by clustering of the ICs with a dipole residual variance of <15 %. Subsequently, event-related spectral perturbations were analyzed in each identified cluster to calculate the power changes across specific frequency ranges. The right precentral gyrus, precuneus, medial frontal gyrus, middle frontal gyrus, superior frontal gyrus, cuneus, cingulate gyrus, left precentral gyrus, middle occipital gyrus, and cingulate gyrus were activated in both cold and hot conditions. In most activated regions, EEG power temporal changes were observed across the frequency ranges and were different between the two conditions. These results may suggest that cold and hot sensations are processed through different temporal brain neural activity patterns in overlapping brain regions.

Right middle occipital gyrus is associated with egocentric spatial orientation during body tilt: Evidence from a repetitive transcranial magnetic stimulation study

Accurate perception of the orientation of external objects relative to the body, known as egocentric spatial orientation, is fundamental to performing action. Previously, we found via behavioural and magnetic resonance imaging voxel-based morphometry studies that egocentric spatial orientation is strongly distorted when the whole body is tilted with respect to gravity, and that the magnitude of this perceptual distortion is correlated with the grey matter volume of the right middle occipital gyrus (rMOG). In the present study, we further validated the association between the neural processing in the rMOG and the perceptual distortion by transiently suppressing neural activity in this region using low-frequency repetitive transcranial magnetic stimulation (rTMS) and evaluating the consequent effect on perceptual distortion. Our results showed that rTMS over the rMOG significantly reduced perceptual distortions when the body was tilted in the frontal plane, while it did not affect egocentric spatial orientation in the upright position. No significant changes in perceptual distortion were observed when rTMS was applied to another cortical candidate (the right temporo-parietal junction). These results provide evidence that neural processing in the rMOG is associated with body tilt-related perceptual distortion, suggesting that the rMOG may be engaged in egocentric spatial orientation related to gravitational information.

Joyful growth vs. compulsive hedonism: A meta-analysis of brain activation on romantic love and addictive disorders

Due to the similarities in behavioral characteristics between romantic love and addictive disorders, the concept of being "addicted to someone" transcends mere literary metaphor, expanding perspectives on the study of romantic love and inspiring interventions for addiction. However, there has been a lack of studies systematically exploring the similarities and differences between romantic love and addiction at the neural level. In this study, we conducted an extensive literature search, incorporating 21 studies on romantic love and 28 on addictive disorders, focusing on fMRI research utilizing the cue reactivity paradigm. Using Activation Likelihood Estimation, we examined the similarities and differences in the neural mechanisms underlying love and addiction. The results showed that the anterior cingulate cortex (ACC) exhibited both shared and distinct activation clusters between romantic love and addictive disorders. Furthermore, ventromedial prefrontal cortex (VMPFC) was more frequently activated in romantic love than in addictive disorders, while greater activation within the posterior cingulate cortex (PCC) was found in addictive disorder compared with romantic love. We discussed that the activation of ACC and VMPFC may symbolize self-expansion, a process that characterizes the development of romantic love, contributing to a more enriched self. Our study suggests that while romantic love and addictive disorders share a common neural foundation, the discernible differences in their neural representations distinguish them as joyful growth versus compulsive hedonism.

Alterations of regional brain activity and corresponding brain circuits in drug-naïve adolescents with nonsuicidal self-injury

Nonsuicidal self-injury (NSSI) is one of the major public health problems endangering adolescents. However, the neural mechanisms of NSSI is still unclear. The purpose of this study was to explore regional brain activity and corresponding brain circuits in drug-naïve adolescents with NSSI using amplitude of low-frequency fluctuations (ALFF) combined with functional connectivity (FC) analysis. Thirty-two drug-naïve adolescents with NSSI (NSSI group) and 29 healthy controls matched for sex, age, and level of education (HC group) were enrolled in this study. ALFF and seed-based FC analyses were used to examine the alterations in regional brain activity and corresponding brain circuits. The correlation between ALFF or FC values of aberrant brain regions and clinical characteristics were detected by Pearson correlation analysis. The NSSI group showed increased ALFF in the left inferior and middle occipital gyri, lingual gyrus, and fusiform gyrus; additionally, decreased ALFF in the right medial cingulate gyrus, left anterior cingulate gyrus, and left medial superior frontal gyrus compared to those in the HC group. With the left inferior occipital gyrus as seed, the NSSI group showed increased FC between the left inferior occipital gyrus and the bilateral superior parietal gyrus, right inferior parietal angular gyrus, right inferior frontal gyrus of the insular region, and left precuneus relative to that the HC group. With the left anterior cingulate gyrus as seed, the NSSI group showed increased FC between the left anterior cingulate gyrus and right dorsolateral superior frontal gyrus. With the left lingual gyrus as seed, the NSSI group showed increased FC between the left lingual gyrus and right middle frontal gyrus, and decreased FC between the left lingual gyrus and the left superior temporal gyrus, right supplementary motor area, and left rolandic operculum. With the left fusiform gyrus as seed, the NSSI group showed increased FC between the left fusiform gyrus and left middle and inferior temporal gyrus, and decreased FC between the left fusiform gyrus and the bilateral postcentral gyrus, right precentral gyrus, right lingual gyrus, and left inferior parietal angular gyrus. Moreover, the FC value between the left fusiform gyrus and left inferior temporal gyrus was positively correlated with suicidal ideations score. This study highlights alterations in regional brain activity and corresponding brain circuits in brain regions related to visual and emotional regulation functions in drug-naïve adolescents with NSSI. These findings may facilitate better understand the underlying neural mechanisms of NSSI in adolescents.

iTBS reveals the roles of domain-general cognitive control and language-specific brain regions during word formation rule learning

Repeated exposure to word forms and meanings improves lexical knowledge acquisition. However, the roles of domain-general and language-specific brain regions during this process remain unclear. To investigate this, we applied intermittent theta burst stimulation over the domain-general (group left dorsolateral prefrontal cortex) and domain-specific (Group L IFG) brain regions, with a control group receiving sham intermittent theta burst stimulation. Intermittent theta burst stimulation effects were subsequently assessed in functional magnetic resonance imaging using an artificial word learning task which consisted of 3 learning phases. A generalized psychophysiological interaction analysis explored the whole brain functional connectivity, while dynamic causal modeling estimated causal interactions in specific brain regions modulated by intermittent theta burst stimulation during repeated exposure. Compared to sham stimulation, active intermittent theta burst stimulation improved word learning performance and reduced activation of the left insula in learning phase 2. Active intermittent theta burst stimulation over the domain-general region increased whole-brain functional connectivity and modulated effective connectivity between brain regions during repeated exposure. This effect was not observed when active intermittent theta burst stimulation was applied to the language-specific region. These findings suggest that the domain-general region plays a crucial role in word formation rule learning, with intermittent theta burst stimulation enhancing whole-brain connectivity and facilitating efficient information exchange between key brain regions during new word learning.

Dissonant music engages early visual processing

The neuroscientific examination of music processing in audio-visual contexts offers a valuable framework to assess how auditory information influences the emotional encoding of visual information. Using fMRI during naturalistic film viewing, we investigated the neural mechanisms underlying the effect of music on valence inferences during mental state attribution. Thirty-eight participants watched the same short-film accompanied by systematically controlled consonant or dissonant music. Subjects were instructed to think about the main character's intentions. The results revealed that increasing levels of dissonance led to more negatively valenced inferences, displaying the profound emotional impact of musical dissonance. Crucially, at the neuroscientific level and despite music being the sole manipulation, dissonance evoked the response of the primary visual cortex (V1). Functional/effective connectivity analysis showed a stronger coupling between the auditory ventral stream (AVS) and V1 in response to tonal dissonance and demonstrated the modulation of early visual processing via top-down feedback inputs from the AVS to V1. These V1 signal changes indicate the influence of high-level contextual representations associated with tonal dissonance on early visual cortices, serving to facilitate the emotional interpretation of visual information. Our results highlight the significance of employing systematically controlled music, which can isolate emotional valence from the arousal dimension, to elucidate the brain's sound-to-meaning interface and its distributive crossmodal effects on early visual encoding during naturalistic film viewing.

Topological regularization of networks in temporal lobe epilepsy: a structural MRI study

Objective

Patients with temporal lobe epilepsy (TLE) often exhibit neurocognitive disorders; however, we still know very little about the pathogenesis of cognitive impairment in patients with TLE. Therefore, our aim is to detect changes in the structural connectivity networks (SCN) of patients with TLE.

Methods

Thirty-five patients with TLE were compared with 47 normal controls (NC) matched according to age, gender, handedness, and education level. All subjects underwent thin-slice T1WI scanning of the brain using a 3.0 T MRI. Then, a large-scale structural covariance network was constructed based on the gray matter volume extracted from the structural MRI. Graph theory was then used to determine the topological changes in the structural covariance network of TLE patients.

Results

Although small-world networks were retained, the structural covariance network of TLE patients exhibited topological irregularities in regular architecture as evidenced by an increase in the small world properties (p < 0.001), normalized clustering coefficient (p < 0.001), and a decrease in the transfer coefficient (p < 0.001) compared with the NC group. Locally, TLE patients showed a decrease in nodal betweenness and degree in the left lingual gyrus, right middle occipital gyrus and right thalamus compared with the NC group (p < 0.05, uncorrected). The degree of structural networks in both TLE (Temporal Lobe Epilepsy) and control groups was distributed exponentially in truncated power law. In addition, the stability of random faults in the structural covariance network of TLE patients was stronger (p = 0.01), but its fault tolerance was lower (p = 0.03).

Conclusion

The objective of this study is to investigate the potential neurobiological mechanisms associated with temporal lobe epilepsy through graph theoretical analysis, and to examine the topological characteristics and robustness of gray matter structural networks at the network level.

Psychological symptoms and brain activity alterations in women with PCOS and their relation to the reduced quality of life: a narrative review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common feminine endocrine disorder, characterized by androgen excess, ovulatory dysfunction, and polycystic ovarian morphology. The negative impact of symptoms on the quality of life (QoL) of patients is still not clear.

PURPOSE

The present review aimed at studying the impact of the symptoms, the psychological symptoms, and brain alterations in women with PCOS.

METHODS

A systematic search was undertaken for studies that assessed the impact of PCOS symptoms on QoL, psychological symptoms, and brain alterations in PCOS patients.

RESULTS

Most of the information about QoL came from psychometric studies, which used culture-based questionnaires. Alterations of sleep quality, body image, and mood disorders can negatively affect the QoL of the patients. Sexual satisfaction and desire were affected by PCOS. Brain imaging studies showed functional alterations that are associated with impairments of visuospatial working memory, episodic and verbal memory, attention, and executive function.

CONCLUSIONS

Several factors can negatively influence the quality of life of the patients, and they are directly related to hyperandrogenism and the risk of infertility. In particular, obesity, hirsutism, acne, and the fear of infertility can have a direct impact on self-esteem and sexual function. Metabolic and psychiatric comorbidities, such as mood, anxiety, and eating disorders, can affect the well-being of the patients. Moreover, specific cognitive alterations, such as impairments in attention and memory, can limit PCOS patients in a series of aspects of daily life.

Brain local stability and network flexibility of table tennis players: a 7T MRI study

Table tennis players have adaptive visual and sensorimotor networks, which are the key brain regions to acquire environmental information and generate motor output. This study examined 20 table tennis players and 21 control subjects through ultrahigh field 7 Tesla magnetic resonance imaging. First, we measured percentage amplitude of fluctuation across five different frequency bands and found that table tennis players had significantly lower percentage amplitude of fluctuation values than control subjects in 18 brain regions, suggesting enhanced stability of spontaneous brain fluctuation amplitudes in visual and sensorimotor networks. Functional connectional analyses revealed increased static functional connectivity between two sensorimotor nodes and other frontal-parietal regions among table tennis players. Additionally, these players displayed enhanced dynamic functional connectivity coupled with reduced static connectivity between five nodes processing visual and sensory information input, and other large-scale cross-regional areas. These findings highlight that table tennis players undergo neural adaptability through a dual mechanism, characterized by global stability in spontaneous brain fluctuation amplitudes and heightened flexibility in visual sensory networks. Our study offers novel insights into the mechanisms of neural adaptability in athletes, providing a foundation for future efforts to enhance cognitive functions in diverse populations, such as athletes, older adults, and individuals with cognitive impairments.

Disrupted brain structural networks associated with depression and cognitive dysfunction in cerebral small vessel disease with microbleeds

Emerging evidence highlights cerebral microbleeds (CMBs) as hallmarks of cerebral small vessel disease (CSVD) underlying depression and cognitive dysfunction. This study aimed to reveal how depression and cognition-related white matter (WM) abnormalities are topologically presented, and the network-level structural disruptions associated with CMBs in CSVD. We used probabilistic diffusion tractography and graph theory to investigate brain WM network topology in CSVD patients with (n = 64, CSVD-c) and without (n = 138, CSVD-n) CMBs and 90 healthy controls. Then we evaluated the Pearson's correlations between disrupted network metrics and neuropsychological parameters. For global topology, the CSVD-c group exhibited significantly decreased global (Eglob) and local (Eloc) efficiency and increased shortest path length compared with the controls, while no significant difference was found between the CSVD-c and CSVD-n groups. For regional topology, although all groups showed highly similar hub distributions, compare with control group, the CSVD-c group exhibited significantly decreased nodal efficiency mainly in the bilateral supplementary motor area (SMA), median cingulate gyrus (DCG) and right orbital middle frontal gyrus, while the CSVD-n group showed significantly decreased nodal efficiency only in the right SMA. Notably, Eglob, Eloc and nodal efficiency of the right anterior cingulate gyrus, DCG, middle temporal gyrus and left insula showed significantly negative correlations with depression score, significantly positive correlations with Rey auditory verbal learning test and symbol digit modalities test scores in CSVD-n group, as well as significantly negative correlations with Stroop color-word test scores in CSVD-c group. The WM networks of CSVD patients are characterized by decreased global integration and local specialization, and decreased nodal efficiency highly related to depression and cognitive dysfunction in the attention, default mode network and sensorimotor regions. These findings provide new insight into the neurobiological mechanisms of CSVD and concomitant affective and cognitive disorders.

Report of a Novel Homozygous Intragenic DCC Duplication and a Review of Literature of Developmental Split-Brain Syndrome aka Horizontal Gaze Palsy with Progressive Scoliosis-2 with Impaired Intellectual Development Syndrome

Introduction

Horizontal gaze palsy with progressive scoliosis-2 (HGPPS2, MIM 617542) with impaired intellectual development aka developmental split-brain syndrome is an ultra-rare congenital disorder caused by pathogenic biallelic variants in the deleted in colorectal cancer (DCC) gene.

Case Presentation

We report the clinical and genetic characterization of a Syrian patient with a HGPPS2 phenotype and review the previously published cases of HGPPS2. The genetic screening was performed using exome sequencing on Illumina platform. Genetic analysis revealed a novel DCC c.(?_1912)_(2359_?)dup, p.(Ser788Tyrfs*4) variant segregating recessively in the family. This type of variant has not been described previously in the HGPPS2 patients. To date, including the case reported here, three different homozygous pathogenic frameshift variants, one homozygous missense variant, and an intragenic duplication in the DCC gene have been reported in 8 patients with the HGPPS2 syndrome.

Conclusion

The analysis of duplications and deletions in the DCC should be included in the routine genetic diagnostic evaluation of patients with suspected HGPPS2. This report expands the knowledge of phenotypic and genotypic spectrum of pathogenic variants causing HGPPS2.

Universal pictures: A lithophane codex helps teenagers with blindness visualize nanoscopic systems

People with blindness have limited access to the high-resolution graphical data and imagery of science. Here, a lithophane codex is reported. Its pages display tactile and optical readouts for universal visualization of data by persons with or without eyesight. Prototype codices illustrated microscopy of butterfly chitin-from N-acetylglucosamine monomer to fibril, scale, and whole insect-and were given to high schoolers from the Texas School for the Blind and Visually Impaired. Lithophane graphics of Fischer-Spier esterification reactions and electron micrographs of biological cells were also 3D-printed, along with x-ray structures of proteins (as millimeter-scale 3D models). Students with blindness could visualize (describe, recall, distinguish) these systems-for the first time-at the same resolution as sighted peers (average accuracy = 88%). Tactile visualization occurred alongside laboratory training, synthesis, and mentoring by chemists with blindness, resulting in increased student interest and sense of belonging in science.

Hippocampal volume and resting-state functional connectivity on magnetic resonance imaging in patients with Parkinson and depression

Background

Recent structural and functional imaging studies of depression in Parkinson disease (DPD) have failed to reveal the relevant mechanism, and relatively few studies have been conducted on limbic systems such as the hippocampus. This study thus aimed to gain new insights into the pathogenesis of DPD by detecting the changes in the hippocampal structure and the resting-state functional connectivity (FC) of patients with DPD.

Methods

This study included 30 patients with DPD (DPD group), 30 patients with nondepressed Parkinson disease (NDPD; NDPD group), and 30 normal controls (NCs; NC group) with no significant age or gender differences with the DPD group. The Hamilton Depression Rating Scale (HAMD) and three-dimensional T1-weighted imaging and blood oxygen level-dependent imaging data of all patients were collected. The hippocampal volumes were measured using MATLAB software (MathWorks). The correlation between hippocampal volume and the HAMD score in the DPD group was analyzed with Pearson correlation coefficient. The bilateral hippocampi were used as the regions of interest and as the seed points for FC. FC analysis was performed between the preprocessed functional data of the whole brain and the two seed points with Data Processing Assistant for Resting-State and Statistical Parametric Mapping 8 software, respectively. The correlation between FC and HAMD scores in the patients with DPD was determined using partial correlation analysis.

Results

Compared with those in the NC group and the NDPD group, the bilateral hippocampal volumes in the DPD group were significantly decreased (P<0.05). There was a negative correlation between the bilateral hippocampal volume and the HAMD score in the DPD group (P<0.05). Compared with that of the NDPD group, the FC of the right hippocampus with the right occipital lobe and left precuneus was reduced in the DPD group. In the DPD group, the FC values of the right hippocampus, right occipital lobe, and left anterior cuneiform lobe were negatively correlated with HAMD scores.

Conclusions

The volume of bilateral hippocampi in patients with DPD is significantly decreased and negatively correlated with the severity of depressive disorder. The weakened FC of the right hippocampus to the right occipital lobe and the left precuneus may play an important role in the neurological basis of DPD.

Altered small-world and disrupted topological properties of functional connectivity networks in patients with nonarteritic anterior ischemic optic neuropathy

BACKGROUND

Nonarteritic anterior ischemic optic neuropathy (NAION) is a disease of the optic nerve, but its effect on brain network topology is still unclear.This study aimed to investigate brain network alterations in NAION patients and to explore their relationship with functional impairment.

METHODS

Resting-state functional MRI data were collected from 23 NAION patients and 23 matched healthy control subjects.We used graph theory analysis to investigate the global and nodal network topological properties,and network-based statistical (NBS) methods were used to explore intergroup differences in functional connectivity (FC) strength.

RESULTS

Compared to the control group, NAION patients had lower global efficiency, normalized clustering coefficient and small-world values and higher characteristic path length (P < 0.05). In the hub distributions of functional networks, the NAION group had one hub region disappearing and four hub regions appearing in nodal degree centrality (Dc), and two hubs disappearing and one hub region appearing in nodal betweenness centrality (Bc). The NAION group also had enhanced brain FC primarily associated with the frontal, prefrontal, parietal lobes and cerebellum. Furthermore, the right temporal pole, superior temporal gyrus (r = -0.424), the right inferior temporal gyrus (r = -0.414), the right cerebellar lobule Ⅵ (r = 0.450), and the left cerebellar lobule crus Ⅰ (r = 0.584) were significantly correlated with clinical severity.

CONCLUSION

NAION patients show disruption and redistribution of FC in specific regions of the brain network, which may be associated with visual impairment.

Task-dependent spatial processing in the visual cortex

To solve spatial tasks, the human brain asks for support from the visual cortices. Nonetheless, representing spatial information is not fixed but depends on the reference frames in which the spatial inputs are involved. The present study investigates how the kind of spatial representations influences the recruitment of visual areas during multisensory spatial tasks. Our study tested participants in an electroencephalography experiment involving two audio-visual (AV) spatial tasks: a spatial bisection, in which participants estimated the relative position in space of an AV stimulus in relation to the position of two other stimuli, and a spatial localization, in which participants localized one AV stimulus in relation to themselves. Results revealed that spatial tasks specifically modulated the occipital event-related potentials (ERPs) after the onset of the stimuli. We observed a greater contralateral early occipital component (50-90 ms) when participants solved the spatial bisection, and a more robust later occipital response (110-160 ms) when they processed the spatial localization. This observation suggests that different spatial representations elicited by multisensory stimuli are sustained by separate neurophysiological mechanisms.

Sound-encoded faces activate the left fusiform face area in the early blind

Face perception in humans and nonhuman primates is accomplished by a patchwork of specialized cortical regions. How these regions develop has remained controversial. In sighted individuals, facial information is primarily conveyed via the visual modality. Early blind individuals, on the other hand, can recognize shapes using auditory and tactile cues. Here we demonstrate that such individuals can learn to distinguish faces from houses and other shapes by using a sensory substitution device (SSD) presenting schematic faces as sound-encoded stimuli in the auditory modality. Using functional MRI, we then asked whether a face-selective brain region like the fusiform face area (FFA) shows selectivity for faces in the same subjects, and indeed, we found evidence for preferential activation of the left FFA by sound-encoded faces. These results imply that FFA development does not depend on experience with visual faces per se but may instead depend on exposure to the geometry of facial configurations.

Frequency Dependent Changes of Regional Homogeneity in Children with Growth Hormone Deficiency

Abnormal spontaneous neural activity in children with growth hormone deficiency (GHD) has been found in previous resting-state functional magnetic resonance imaging (rs-fMRI) studies. Nevertheless, the spontaneous neural activity of GHD in different frequency bands is still unclear. Here, we combined rs-fMRI and regional homogeneity (ReHo) methods to analyze the spontaneous neural activity of 26 GHD children and 15 healthy controls (HCs) with age- and sex-matching in four frequency bands: slow-5 (0.014-0.031 Hz), slow-4 (0.031-0.081 Hz), slow-3 (0.081-0.224 Hz), and slow-2 (0.224-0.25 Hz). In the slow-5 band, GHD children compared with HCs displayed higher ReHo in the left dorsolateral part of the superior frontal gyrus, triangular part of the inferior frontal gyrus, precentral gyrus and middle frontal gyrus, and right angular gyrus, while lower ReHo in the right precentral gyrus, and several medial orbitofrontal regions. In the slow-4 band, GHD children relative to HCs revealed increased ReHo in the right middle temporal gyrus, whereas reduced ReHo in the left superior parietal gyrus, right middle occipital gyrus, and bilateral medial parts of the superior frontal gyrus. In the slow-2 band, compared with HCs, GHD children showed increased ReHo in the right anterior cingulate gyrus, and several prefrontal regions, while decreased ReHo in the left middle occipital gyrus, and right fusiform gyrus and anterior cingulate gyrus. Our findings demonstrate that regional brain activity in GHD children exhibits extensive abnormalities, and these abnormalities are related to specific frequency bands, which may provide bases for understanding its pathophysiology significance.

Brain-gut axis mechanism of subthreshold nonsuicidal self-injury addictive features in adolescents

Nonsuicidal self-injury (NSSI) is associated with an increased risk of suicide. As the diagnostic criteria outlined in DSM-5 and other related clinical studies, a patient must have engaged in self-injurious behavior at least 5 times within the past year. However, patients with fewer than 5 self-injury behaviors should not be ignored. Our study included 46 adolescents aged 10-19 years with subthreshold NSSI (sNSSI), along with a control group of 50 healthy adolescents matched for age and other factors. We collected resting-state functional magnetic resonance imaging data and stool samples. The Ottawa Self-Injury Inventory and Deliberate Self-Harm Inventory were used to evaluate self-harm behaviors and addictive features. Local brain activity was assessed using fractional amplitude of low-frequency fluctuations (fALFF), and brain regions with abnormal fALFF were selected as seeds for whole-brain functional connectivity analysis. Stool samples were identified using 16S rDNA amplicon sequencing, and the LDA Effect Size method was used to explore significant differences between grouped samples. Mediation analysis was performed to investigate the brain-gut axis mechanisms of addictive features in sNSSI. We found that compared with healthy controls, sNSSI patients have abnormal fALFF in left thalamus and posterior cingulate cortex, dysconnectivities of left thalamus, and decreased Prevotellaceae. Our results suggested that addictive features of sNSSI may have a brain-gut mechanism. Furtherly, patients with 1-4 NSSI behaviors in the past year should have separate name for identification, such as "subthreshold NSSI".

The effects of laser acupuncture dosage at PC6 (Neiguan) on brain reactivity: a pilot resting-state fMRI study

Previous studies indicated that laser acupuncture (LA) may effectively treat various medical conditions. However, brain responses associated with LA intervention have not been fully investigated. This study is focused on the effect of LA with different energy density (ED) in brain using resting-state functional magnetic resonance imaging (fMRI). We hypothesized that different ED would elicit various brain responses. We enrolled healthy adults participants and selected bilateral PC6 (Neiguan) as the intervention points. LA was applied, respectively, with ED of 0, 7.96, or 23.87 J/cm2. Two 500-s resting-state fMRI scans were acquired before and after intervention, respectively. The functional connectivity (FC) was calculated between autonomic nerve system-regulation associated brainstem structures and other brain regions. Compared to other dosages, the FC between rostral ventrolateral medulla and orbitofrontal cortex has more enhanced; the FC between caudal ventrolateral medulla, nucleus of the solitary tract/nucleus ambiguus, and dorsal motor nucleus of the vagus and somatosensory area has more weakened when ED was 23.87 J/cm2. Different dosages of LA have demonstrated varied regions of FC changes between regions of interest and other brain areas, which indicated that variations in EDs might influence the clinical efficacy and subsequent impacts through distinct neural pathways within the brain.

Neurovascular coupling dysfunction in high myopia patients: Evidence from a multi-modal magnetic resonance imaging analysis

BACKGROUND AND PURPOSE

To investigate neurovascular coupling dysfunction in high myopia (HM) patients.

MATERIALS AND METHODS

A total of 37 HM patients and 36 healthy controls were included in this study. Degree centrality (DC), regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF), and fractional ALFF (fALFF) maps were employed to represent neuronal activity. Cerebral blood perfusion was characterized by cerebral blood flow (CBF). The correlation coefficient was calculated to reflect the relationship between neuronal activity and cerebral blood perfusion. Pearson partial correlation analysis was utilized to evaluate the association between HM dysfunction and clinical indicators.

RESULTS

HM patients exhibited significant alterations in neurovascular coupling across 37 brain regions compared to healthy controls. The brain regions with marked changes varied among the four neurovascular coupling patterns, including the middle frontal gyrus, superior occipital gyrus, middle occipital gyrus, and fusiform gyrus. Additionally, the superior frontal gyrus orbital part, medial superior frontal gyrus, inferior occipital gyrus, and dorsolateral superior frontal gyrus displayed significant changes in three coupling patterns. In HM patients, the ReHo-CBF changes in the inferior frontal gyrus orbital part were positively correlated with best-corrected visual acuity (BCVA) and refractive diopter changes. Similarly, the ALFF-CBF changes in the inferior frontal gyrus orbital part showed a positive correlation with refractive diopter changes. ReHo-CBF and ALFF-CBF alterations in the paracentral lobule were positively correlated with BCVA and refractive diopter changes.

CONCLUSION

Our findings underscore the abnormal alterations in neurovascular coupling across multiple brain regions in HM patients. These results suggest that neurovascular dysfunction in HM patients may be associated with an aberrant visual regulation mechanism.

Task-dependent functional connectivity of pain is associated with the magnitude of placebo analgesia in pain-free individuals

BACKGROUND

Task-based functional connectivity (FC) of pain-related regions resulting from expectancy-based placebo induction has yet to be examined, limiting our understanding of regions and networks associated with placebo analgesia.

METHODS

Fifty-five healthy pain-free adults over 18 (M = 22.8 years, SD = 7.75) were recruited (65.5% women; 63.6% non-Hispanic/Latino/a/x; 58.2% White). Participants completed a baseline followed by a placebo session involving the topical application of an inactive cream in the context of an expectancy-enhancing instruction set. Noxious heat stimuli were applied to the thenar eminence of the right palm using an fMRI-safe thermode. Stimulus intensity was individually calibrated to produce pain ratings of approximately 40 on a 100-point visual analogue scale.

RESULTS

A total of 67.3% of the participants showed a reduction in pain intensity in the placebo condition with an average reduction in pain across the whole sample of 12.7%. Expected pain intensity was associated with reported pain intensity in the placebo session (b = 0.32, p = 0.004, R2  = 0.15). Voxel-wise analyses indicated seven clusters with significant activation during noxious heat stimulation at baseline (pFDR  < 0.05). Generalized psychophysiological interaction analysis suggested that placebo-related FC changes between middle frontal gyrus-superior parietal lobule during noxious stimulation were significantly associated with the magnitude of pain reduction (pFDR  < 0.05).

CONCLUSIONS

Results suggest that stronger expectancy-based placebo responses might be underpinned by greater FC among attentional and somatosensory regions.

SIGNIFICANCE

This article provides support and insight for task-dependent functional connectivity differences related to the magnitude of placebo analgesia. Our findings provide key support that the magnitude of expectation-based placebo response depends on the coupling of regions associated with somatosensory and attentional processing.

A Novel Neurorehabilitation Prognosis Prediction Modeling on Separated Left-Right Hemiplegia Based on Brain-Computer Interfaces Assisted Rehabilitation

It is essential for neuroscience and clinic to estimate the influence of neuro-intervention after brain damage. Most related studies have used Mirrored Contralesional-Ipsilesional hemispheres (MCI) methods flipping the axial neuroimaging on the x-axis in prognosis prediction. But left-right hemispheric asymmetry in the brain has become a consensus. MCI confounds the intrinsic brain asymmetry with the asymmetry caused by unilateral damage, leading to questions about the reliability of the results and difficulties in physiological explanations. We proposed the Separated Left-Right hemiplegia (SLR) method to model left and right hemiplegia separately. Two pipelines have been designed in contradistinction to demonstrate the validity of the SLR method, including MCI and removing intrinsic asymmetry (RIA) pipelines. A patient dataset with 18 left-hemiplegic and 22 right-hemiplegic stroke patients and a healthy dataset with 40 subjects, age- and sex-matched with the patients, were selected in the experiment. Blood-Oxygen Level-Dependent MRI and Diffusion Tensor Imaging were used to build brain networks whose nodes were defined by the Automated Anatomical Labeling atlas. We applied the same statistical and machine learning framework for all pipelines, logistic regression, artificial neural network, and support vector machine for classifying the patients who are significant or non-significant responders to brain-computer interfaces assisted training and optimal subset regression, support vector regression for predicting post-intervention outcomes. The SLR pipeline showed 5-15% improvement in accuracy and at least 0.1 upgrades in [Formula: see text], revealing common and unique recovery mechanisms after left and right strokes and helping clinicians make rehabilitation plans.

Metamodal Coupling of Vibrotactile and Auditory Speech Processing Systems through Matched Stimulus Representations

It has been postulated that the brain is organized by "metamodal," sensory-independent cortical modules capable of performing tasks (e.g., word recognition) in both "standard" and novel sensory modalities. Still, this theory has primarily been tested in sensory-deprived individuals, with mixed evidence in neurotypical subjects, thereby limiting its support as a general principle of brain organization. Critically, current theories of metamodal processing do not specify requirements for successful metamodal processing at the level of neural representations. Specification at this level may be particularly important in neurotypical individuals, where novel sensory modalities must interface with existing representations for the standard sense. Here we hypothesized that effective metamodal engagement of a cortical area requires congruence between stimulus representations in the standard and novel sensory modalities in that region. To test this, we first used fMRI to identify bilateral auditory speech representations. We then trained 20 human participants (12 female) to recognize vibrotactile versions of auditory words using one of two auditory-to-vibrotactile algorithms. The vocoded algorithm attempted to match the encoding scheme of auditory speech while the token-based algorithm did not. Crucially, using fMRI, we found that only in the vocoded group did trained-vibrotactile stimuli recruit speech representations in the superior temporal gyrus and lead to increased coupling between them and somatosensory areas. Our results advance our understanding of brain organization by providing new insight into unlocking the metamodal potential of the brain, thereby benefitting the design of novel sensory substitution devices that aim to tap into existing processing streams in the brain.SIGNIFICANCE STATEMENT It has been proposed that the brain is organized by "metamodal," sensory-independent modules specialized for performing certain tasks. This idea has inspired therapeutic applications, such as sensory substitution devices, for example, enabling blind individuals "to see" by transforming visual input into soundscapes. Yet, other studies have failed to demonstrate metamodal engagement. Here, we tested the hypothesis that metamodal engagement in neurotypical individuals requires matching the encoding schemes between stimuli from the novel and standard sensory modalities. We trained two groups of subjects to recognize words generated by one of two auditory-to-vibrotactile transformations. Critically, only vibrotactile stimuli that were matched to the neural encoding of auditory speech engaged auditory speech areas after training. This suggests that matching encoding schemes is critical to unlocking the brain's metamodal potential.

Loss of action-related function and connectivity in the blind extrastriate body area

The Extrastriate Body Area (EBA) participates in the visual perception and motor actions of body parts. We recently showed that EBA’s perceptual function develops independently of visual experience, responding to stimuli with body-part information in a supramodal fashion. However, it is still unclear if the EBA similarly maintains its action-related function. Here, we used fMRI to study motor-evoked responses and connectivity patterns in the congenitally blind brain. We found that, unlike the case of perception, EBA does not develop an action-related response without visual experience. In addition, we show that congenital blindness alters EBA’s connectivity profile in a counterintuitive way—functional connectivity with sensorimotor cortices dramatically decreases, whereas connectivity with perception-related visual occipital cortices remains high. To the best of our knowledge, we show for the first time that action-related functions and connectivity in the visual cortex could be contingent on visuomotor experience. We further discuss the role of the EBA within the context of visuomotor control and predictive coding theory.

Aberrant neurovascular coupling in Leber's hereditary optic neuropathy: Evidence from a multi-model MRI analysis

The study aimed to investigate the neurovascular coupling abnormalities in Leber's hereditary optic neuropathy (LHON) and their associations with clinical manifestations. Twenty qualified acute Leber's hereditary optic neuropathy (A-LHON, disease duration ≤ 1 year), 29 chronic Leber's hereditary optic neuropathy (C-LHON, disease duration > 1 year), as well as 37 healthy controls (HCs) were recruited. The neurovascular coupling strength was quantified as the ratio between regional homogeneity (ReHo), which represents intrinsic neuronal activity and relative cerebral blood flow (CBF), representing microcirculatory blood supply. A one-way analysis of variance was used to compare intergroup differences in ReHo/CBF ratio with gender and age as co-variables. Pearson's Correlation was used to clarify the association between ReHo, CBF, and neurovascular coupling strength. Furthermore, we applied linear and exponential non-linear regression models to explore the associations among ReHo/CBF, disease duration, and neuro-ophthalmological metrics. Compared with HCs, A_LHON, and C_LHON patients demonstrated a higher ReHo/CBF ratio than the HCs in the bilateral primary visual cortex (B_CAL), which was accompanied by reduced CBF while preserved ReHo. Besides, only C_LHON had a higher ReHo/CBF ratio and reduced CBF in the left middle temporal gyrus (L_MTG) and left sensorimotor cortex (L_SMC) than the HCs, which was accompanied by increased ReHo in L_MTG (p < 1.85e^-3, Bonferroni correction). A-LHON and C-LHON showed a negative Pearson correlation between ReHo/CBF ratio and CBF in B_CAL, L_SMC, and L_MTG. Only C_LHON showed a weak positive correlation between ReHo/CBF ratio and ReHo in L_SMC and L_MTG (p < 0.05, uncorrected). Finally, disease duration was positively correlated with ReHo/CBF ratio of L_SMC (Exponential: Radj² = 0.23, p = 8.66e^-4, Bonferroni correction). No statistical correlation was found between ReHo/CBF ratio and neuro-ophthalmological metrics (p > 0.05, Bonferroni correction). Brain neurovascular "dyscoupling" within and outside the visual system might be an important neurological mechanism of LHON.

Distinct patterns of functional brain network integration between treatment-resistant depression and non treatment-resistant depression: A resting-state functional magnetic resonance imaging study

BACKGROUND

Previous neuroimaging has paid little attention to the differences in brain network integration between patients with treatment-resistant depression(TRD) and non-TRD (nTRD), and the relationship between their impaired brain network integration and clinical symptoms has not been elucidated.

METHOD

Eighty one major depressive disorder (MDD) patients (40 in TRD, 41 in nTRD) and 40 healthy controls (HCs) were enrolled for the functional magnetic resonance imaging (fMRI) scans. A seed-based functional connectivity (FC) method was used to investigate the brain network abnormalities of default mode network (DMN), affective network (AN), salience network (SN) and cognitive control network (CCN) for the MDD. Finally, the correlation was analyzed between the abnormal FCs and 17-item Hamilton Rating Scale for Depression scale (HAMD-17) scores.

RESULTS

Compared with the HC group, the FCs in DMN, AN, SN, CCN were altered in both the TRD and nTRD groups. Compared with the nTRD group, FC alterations in the AN and CCN were more abnormal in the TRD group, and the FC alterations were generally decreased at the SN in the TRD group. In addition, the FC values of right dorsolateral prefrontal cortices and left caudate nucleus in the TRD group and the FC values of right subgenual anterior cingulate cortex and left middle temporal gyrus in the nTRD group were positively correlated with HAMD-17 scale scores.

CONCLUSIONS

Abnormal FCs are present in four brain networks (DMN, AN, SN, CCN) in both the TRD and nTRD groups. Except of DMN, FCs in AN, SN and CCN maybe underlay the neurobiological mechanism in differentiating TRD from nTRD.

Neural bases of motivated forgetting of autobiographical memories

It is important for mental health to be able to control unwanted intrusive memories. Previous studies suggest that middle frontal gyrus (MFG) down regulates pathways underlie the suppression of retrieval of general memories. However, the neural basis of motivated forgetting of autobiographical memories is unclear. Therefore, this study used two samples to explore the neural mechanisms of motivated forgetting of self-referential memories. Every participant provided 40 life events (20 negative and 20 neutral) from their past personal experience, and then completed the Think/No-Think task while undergoing functional magnetic resonance imaging (fMRI). The first sample showed a significant reduction in recall in the No-Think condition relative to the Think condition. Attempting to exclude negative autobiographical memories from awareness was associated with increased activity in the right MFG, superior frontal gyrus (SFG), and inferior frontal gyrus (IFG), while reduced activity was observed in the bilateral Brodmann areas BA18 and BA19, bilateral medial prefrontal cortex (mPFC), bilateral precuneus, bilateral post cingulate cortex (PCC), the left parahippocampus, and the left hippocampus. Functional connectivity analyses showed that the right MFG projected into the bilateral mPFC, bilateral precuneus, and bilateral middle occipital gyrus (MOG) for negative autobiographical memories. The second sample replicated the results of the first sample at both the behavioral and brain levels. These results suggest that retrieval suppression of autobiographical memories involve the pathway between the MFG and the mPFC and precuneus to exclude self-referential memories. These results reveal how people engage in motivated forgetting of negative events in their daily lives.

Childhood abuse and cortical gray matter volume in patients with major depressive disorder

Childhood abuse is associated with brain structural alterations; however, few studies have investigated the association between specific types of childhood abuse and cortical volume in patients with major depressive disorder (MDD). We aimed to investigate the association between specific types of childhood abuse and gray matter volumes in patients with MDD. Seventy-five participants with MDD and 97 healthy controls (HCs) aged 19-64 years were included. Cortical gray matter volumes were compared between MDD and HC groups, and also compared according to exposure to each type of specific childhood abuse. Emotional, sexual, and physical childhood abuse were assessed using the 28-item Childhood Trauma Questionnaire. Patients with MDD showed a significantly decreased gray matter volume in the right anterior cingulate gyrus (ACG). Childhood sexual abuse (CSA) was associated with significantly decreased gray matter volume in the right middle occipital gyrus (MOG). In the post-hoc comparison of volumes of the right ACG and MOG, MDD patients with CSA had significantly smaller volumes in the right MOG than did MDD patients without CSA or HCs. The right MOG volume decrease could be a neuroimaging marker associated with CSA and morphological changes in the brain may be involved in the pathophysiology of MDD.

Different characteristics of striatal resting-state functional conectivity in treatment-resistant and non-treatment-resistant depression

Major depressive disorder is associated with a reward deficit manifested by abnormal striatal function. However, differences between treatment-resistant depression (TRD) and non TRD (nTRD) in striatal whole-brain functional connectivity (FC) have not been elucidated. Thirty-eight patients with TRD, 42 patients with nTRD, and 39 healthy controls (HCs) were recruited for this study. A seed-based FC approach was used to analyze abnormalities in six predefined striatal subregion circuits in the three groups of subjects, and further explore the correlation between abnormal FC and clinical symptoms. Results revealed that compared with the nTRD group, the TRD group showed increased FC of the inferior ventral striatum with the bilateral orbital area of the middle frontal gyrus, right cerebellum posterior lobe, left parahippocampal gyrus, left middle occipital gyrus and left lingual gyrus. Compared with the HC group, the TRD group showed a wider range of altered striatal function than the nTRD group. In the TRD group, the HAMD-17 scores were positively correlated with the FC between the right VRP and the left caudate. This study provides new insights into understanding the specificity of TRD striatal circuits.

Characterization of Resting-State Striatal Differences in First-Episode Depression and Recurrent Depression

The presence of reward deficits in major depressive disorder is associated with abnormal striatal function. However, differences in striatal whole-brain functional between recurrent depressive episode (RDE) and first-episode depression (FDE) have not been elucidated. Thirty-three patients with RDE, 27 with FDE, and 35 healthy controls (HCs) were recruited for this study. A seed-based functional connectivity (FC) method was used to analyze abnormalities in six predefined striatal subregion circuits among the three groups of subjects and to further explore the correlation between abnormal FC and clinical symptoms. The results revealed that compared with the FDE group, the RDE group showed higher FC of the striatal subregion with the left middle occipital gyrus, left orbital area of the middle frontal gyrus, and bilateral posterior cerebellar gyrus, while showing lower FC of the striatal subregion with the right thalamus, left inferior parietal lobule, left middle cingulate gyrus, right angular gyrus, right cerebellum anterior lobe, and right caudate nucleus. In the RDE group, the HAMD-17 scores were positively correlated with the FC between the left dorsal rostral putamen and the left cerebellum posterior lobe. This study provides new insights into understanding the specificity of striatal circuits in the RDE group.

Do blind people hear better?

For centuries, anecdotal evidence such as the perfect pitch of the blind piano tuner or blind musician has supported the notion that individuals who have lost their sight early in life have superior hearing abilities compared with sighted people. Recently, auditory psychophysical and functional imaging studies have identified that specific auditory enhancements in the early blind can be linked to activation in extrastriate visual cortex, suggesting crossmodal plasticity. Furthermore, the nature of the sensory reorganization in occipital cortex supports the concept of a task-based functional cartography for the cerebral cortex rather than a sensory-based organization. In total, studies of early-blind individuals provide valuable insights into mechanisms of cortical plasticity and principles of cerebral organization.

Neural substrates of spatial processing and navigation in blindness: An activation likelihood estimation meta-analysis

Even though vision is considered the best suited sensory modality to acquire spatial information, blind individuals can form spatial representations to navigate and orient themselves efficiently in space. Consequently, many studies support the amodality hypothesis of spatial representations since sensory modalities other than vision contribute to the formation of spatial representations, independently of visual experience and imagery. However, given the high variability in abilities and deficits observed in blind populations, a clear consensus about the neural representations of space has yet to be established. To this end, we performed a meta-analysis of the literature on the neural correlates of spatial processing and navigation via sensory modalities other than vision, like touch and audition, in individuals with early and late onset blindness. An activation likelihood estimation (ALE) analysis of the neuroimaging literature revealed that early blind individuals and sighted controls activate the same neural networks in the processing of non-visual spatial information and navigation, including the posterior parietal cortex, frontal eye fields, insula, and the hippocampal complex. Furthermore, blind individuals also recruit primary and associative occipital areas involved in visuo-spatial processing via cross-modal plasticity mechanisms. The scarcity of studies involving late blind individuals did not allow us to establish a clear consensus about the neural substrates of spatial representations in this specific population. In conclusion, the results of our analysis on neuroimaging studies involving early blind individuals support the amodality hypothesis of spatial representations.

Altered regional homogeneity of spontaneous brain activity in patients with toothache: A resting-state functional magnetic resonance imaging study

Toothache (TA) is a common and severe pain, but its effects on the brain are somewhat unclear. In this study, functional magnetic resonance imaging (fMRI) was used to compare regional homogeneity (ReHo) between TA patients and a normal control group and to explore the brain activity changes during TA, establishing the theoretical basis for the mechanism of neuropathic pain. In total, 20 TA patients and 20 healthy controls (HCs) were recruited and underwent assessment of pain, and then resting-state fMRI (rs-fMRI). The ReHo method was used to analyze the original whole-brain images. Pearson’s correlation analysis was used to assess the relationship between mean ReHo values in each brain region and clinical symptoms, and the receiver operating characteristic (ROC) curve was used to conduct correlation analysis on the brain regions studied. The ReHo values of the right lingual gyrus (RLG), right superior occipital gyrus (RSOG), left middle occipital gyrus (LMOG) and right postcentral gyrus (RPG) in the TA group were significantly higher than in HCs. The mean ReHo values in the RLG were positively correlated with the anxiety score (AS) (r = 0.723, p &lt; 0.001), depression score (DS) (r = 0.850, p &lt; 0.001) and visual analogue score (VAS) (r = 0.837, p &lt; 0.001). The mean ReHo values of RSOG were also positively correlated with AS (r = 0.687, p = 0.001), DS (r = 0.661, p = 0.002) and VAS (r = 0.712, p &lt; 0.001). The areas under the ROC curve of specific brain area ReHo values were as follows: RLG, 0.975; RSOG, 0.959; LMOG, 0.975; RPG, 1.000. Various degrees of brain activity changes reflected by ReHo values in different areas of the brain indicate the impact of TA on brain function. These findings may reveal related neural mechanisms underlying TA.

Neural efficiency and proficiency adaptation of effective connectivity corresponding to early and advanced skill levels in athletes of racket sports

This study explored how the neural efficiency and proficiency worked in athletes with different skill levels from the perspective of effective connectivity brain network in resting state. The deconvolved conditioned Granger causality (GC) analysis was applied to functional magnetic resonance imaging (fMRI) data of 35 elite athletes (EAs) and 42 student-athletes (SAs) of racket sports as well as 39 normal controls (NCs), to obtain the voxel-wised hemodynamic response function (HRF) parameters representing the functional segregation and effective connectivity representing the functional integration. The results showed decreased time-to-peak of HRF in the visual attention brain regions in the two athlete groups compared with NC and decreased response height in the advanced motor control brain regions in EA comparing to the nonelite groups, suggesting the neural efficiency represented by the regional HRF was different in early and advanced skill levels. GC analysis demonstrated that the GC values within the middle occipital gyrus had a linear trend from negative to positive, suggesting a stepwise "neural proficiency" of the effective connectivity from NC to SA then to EA. The GC values of the inter-lobe circuits in EA had the trend to regress to NC levels, in agreement with the neural efficiency of these circuits in EA. Further feature selection approach suggested the important role of the cerebral-brainstem GC circuit for discriminating EA. Our findings gave new insight into the complementary neural mechanisms in brain functional segregation and integration, which was associated with early and advanced skill levels in athletes of racket sports.

Specific subsystems of the inferior parietal lobule are associated with hand dysfunction following stroke: A cross-sectional resting-state fMRI study

AIM

The inferior parietal lobule (IPL) plays important roles in reaching and grasping during hand movements, but how reorganizations of IPL subsystems underlie the paretic hand remains unclear. We aimed to explore whether specific IPL subsystems were disrupted and associated with hand performance after chronic stroke.

METHODS

In this cross-sectional study, we recruited 65 patients who had chronic subcortical strokes and 40 healthy controls from China. Each participant underwent the Fugl-Meyer Assessment of Hand and Wrist and resting-state fMRI at baseline. We mainly explored the group differences in resting-state effective connectivity (EC) patterns for six IPL subregions in each hemisphere, and we correlated these EC patterns with paretic hand performance across the whole stroke group and stroke subgroups. Moreover, we used receiver operating characteristic curve analysis to distinguish the stroke subgroups with partially (PPH) and completely (CPH) paretic hands.

RESULTS

Stroke patients exhibited abnormal EC patterns with ipsilesional PFt and bilateral PGa, and five sensorimotor-parietal/two parietal-temporal subsystems were positively or negatively correlated with hand performance. Compared with CPH patients, PPH patients exhibited abnormal EC patterns with the contralesional PFop. The PPH patients had one motor-parietal subsystem, while the CPH patients had one sensorimotor-parietal and three parietal-occipital subsystems that were associated with hand performance. Notably, the EC strength from the contralesional PFop to the ipsilesional superior frontal gyrus could distinguish patients with PPH from patients with CPH.

CONCLUSIONS

The IPL subsystems manifest specific functional reorganization and are associated with hand dysfunction following chronic stroke.

Data for all: Tactile graphics that light up with picture-perfect resolution

People who are blind do not have access to graphical data and imagery produced by science. This exclusion complicates learning and data sharing between sighted and blind persons. Because blind people use tactile senses to visualize data (and sighted people use eyesight), a single data format that can be easily visualized by both is needed. Here, we report that graphical data can be three-dimensionally printed into tactile graphics that glow with video-like resolution via the lithophane effect. Lithophane forms of gel electropherograms, micrographs, electronic and mass spectra, and textbook illustrations could be interpreted by touch or eyesight at ≥79% accuracy (n = 360). The lithophane data format enables universal visualization of data by people regardless of their level of eyesight.

The association between ballroom dance training and empathic concern: Behavioral and brain evidence

Dance is unique in that it is a sport and an art simultaneously. Beyond improving sensorimotor functions, dance training could benefit high-level emotional and cognitive functions. Duo dances also confer the possibility for dancers to develop the abilities to recognize, understand, and share the thoughts and feelings of their dance partners during the long-term dance training. To test this possibility, we collected high-resolution structural and resting-state functional magnetic resonance imaging (MRI) data from 43 expert-level ballroom dancers (a model of long-term exposure to duo dance training) and 40 age-matched and sex-matched nondancers, and measured their empathic ability using a self-report trait empathy scale. We found that ballroom dancers showed higher scores of empathic concern (EC) than controls. The EC scores were positively correlated with years with dance partners but negatively correlated with the number of dance partners for ballroom dancers. These behavioral results were supported by the structural and functional MRI data. Structurally, we observed that the gray matter volumes in the subgenual anterior cingulate cortex (ACC) and EC scores were positively correlated. Functionally, the connectivity between ACC and occipital gyrus was positively correlated with both EC scores and years with dance partners. In addition, the relationship between years with dance partners and EC scores was indirect-only mediated by the ACC-occipital gyrus functional connectivity. Therefore, our findings provided solid evidence for the close link between long-term ballroom dance training and empathy, which deepens our understanding of the neural mechanisms underlying this phenomenon.

Differences in neuroanatomy and functional connectivity between motor subtypes of Parkinson’s disease

Background

The “postural instability/gait difficulty” (PIGD) and “tremor-dominant” (TD) motor subtypes of Parkinson’s disease (PD) differ in their clinical manifestations. The neurological basis of these differences is unclear.

Methods

We performed voxel-based morphometric analysis and measured amplitudes of low-frequency fluctuation (ALFF) on 87 PIGD patients and 51 TD patients. We complemented this neuroanatomical comparison with seed-to-voxel analysis to explore differences in functional connectivity.

Results

The PIGD group showed significantly smaller gray matter volume in the medial frontal gyrus (mainly on the right side) than the TD group. Across all patients, gray matter volume in the medial frontal gyrus correlated negatively with severity of PIGD symptoms after controlling for age (r = −0.250, p = 0.003), but this correlation was not observed in separate analyses of only PIGD or TD patients. The PIGD group showed greater functional connectivity of the right superior frontal gyrus with the left lingual gyrus, right lateral occipital cortex, and right lingual gyrus. ALFF did not differ significantly between the two groups.

Conclusion

Postural instability/gait difficulty may be associated with smaller gray matter volume in medial frontal gyrus than TD, as well as with greater functional connectivity between the right superior frontal gyrus and occipital cortex. These results may help explain the clinical differences between the two motor subtypes of PD.

Language and nonverbal auditory processing in the occipital cortex of individuals who are congenitally blind due to anophthalmia

Individuals with congenital blindness due to bilateral anophthalmia offer a unique opportunity to examine cross-modal plasticity in the complete absence of any stimulation of the 'visual' pathway even during development in utero. Our previous work has suggested that this complete sensory deafferentation results in different patterns of reorganisation compared with those seen in other early blind populations. Here, we further test the functional specialisation of occipital cortex in six well-studied cases with anophthalmia. Whole brain functional MRI was obtained while these human participants and a group of sighted controls performed two experiments involving phonological and semantic processing of words (verbal experiment) and spatial and identity processing of piano chords (nonverbal experiment). Both experiments were predicted to show a dorsal-ventral difference in activity based on the specific task performed. All tasks evoked activation in occipital cortex in the individuals with anophthalmia but not in the sighted controls. For the verbal experiment, both dorsal and ventral occipital areas were strongly activated by the phonological and semantic tasks in anophthalmia. For the nonverbal experiment, both the spatial and the identity task robustly activated the dorsal occipital area V3a but showed inconsistent activity elsewhere in the occipital lobe. V1 was most strongly activated by the verbal tasks, showing greater activity on the left for the verbal task relative to the nonverbal one. For individual anophthalmic participants, however, activity in V1 was inconsistent across tasks and hemispheres with many participants showing activity levels in the control range, which was not significantly above baseline. Despite the homogeneous nature of the cause of blindness in the anophthalmic group, there remain differences in patterns of activation among the individuals with this condition. Investigation at the case level might further our understanding of how post-natal experiences shape functional reorganisation in deafferented cortex.

Alterations of regional spontaneous neuronal activity and corresponding brain circuits related to non-suicidal self-injury in young adults with major depressive disorder

BACKGROUND

Major depressive disorder (MDD) with non-suicidal self-injury (NSSI)(MDD/NSSI) has been found to differ from simple MDD without NSSI (sMDD). This study analyzes the amplitude of low-frequency fluctuations (ALFF) to explore the NSSI-relevant local neural activity, and uses functional connectivity (FC) analysis to explore the NSSI-relevant circuits corresponding to alterations in local regions in young adult patients with MDD/NSSI.

METHODS

A total of 54 patients with MDD/NSSI, 68 patients with sMDD, and 66 matched healthy controls (HCs) were recruited. ALFF and seed-based FC analyses were employed. The NSSI-relevant brain alteration and its associations with clinical variables were examined.

RESULTS

Compared with the sMDD group, the MDD/NSSI group showed higher ALFF in the right lingual gyrus and right middle occipital gyrus; lower ALFF in the right superior frontal gyrus; higher FC values between the right lingual gyrus and left precentral gyrus; and lower FC values between the right middle occipital gyrus and right paracentral gyrus. Within the MDD/NSSI group, ALFF values of the right superior frontal gyrus and right lingual gyrus were positively correlated with the frequency and severity of NSSI.

LIMITATIONS

The sample size was small, and the potential influence of medicine on brain activity was not excluded.

CONCLUSIONS

Our preliminary findings indicate that NSSI-relevant ALFF in the right lingual gyrus, right middle occipital gyrus, and right superior frontal gyrus, as well as the alteration FCs in corresponding brain circuits, may play an important role in the neural basis of MDD/NSSI.

Combination of Group Singular Value Decomposition and eLORETA Identifies Human EEG Networks and Responses to Transcranial Photobiomodulation

Transcranial Photobiomodulation (tPBM) has demonstrated its ability to alter electrophysiological activity in the human brain. However, it is unclear how tPBM modulates brain electroencephalogram (EEG) networks and is related to human cognition. In this study, we recorded 64-channel EEG from 44 healthy humans before, during, and after 8-min, right-forehead, 1,064-nm tPBM or sham stimulation with an irradiance of 257 mW/cm². In data processing, a novel methodology by combining group singular value decomposition (gSVD) with the exact low-resolution brain electromagnetic tomography (eLORETA) was implemented and performed on the 64-channel noise-free EEG time series. The gSVD+eLORETA algorithm produced 11 gSVD-derived principal components (PCs) projected in the 2D sensor and 3D source domain/space. These 11 PCs took more than 70% weight of the entire EEG signals and were justified as 11 EEG brain networks. Finally, baseline-normalized power changes of each EEG brain network in each EEG frequency band (delta, theta, alpha, beta and gamma) were quantified during the first 4-min, second 4-min, and post tPBM/sham periods, followed by comparisons of frequency-specific power changes between tPBM and sham conditions. Our results showed that tPBM-induced increases in alpha powers occurred at default mode network, executive control network, frontal parietal network and lateral visual network. Moreover, the ability to decompose EEG signals into individual, independent brain networks facilitated to better visualize significant decreases in gamma power by tPBM. Many similarities were found between the cortical locations of SVD-revealed EEG networks and fMRI-identified resting-state networks. This consistency may shed light on mechanistic associations between tPBM-modulated brain networks and improved cognition outcomes.