Convergence of modality invariance and attention selectivity in the cortical semantic circuit

AbstractThe human linguistic system is characterized by modality invariance and attention selectivity. Previous studies have examined these properties independently and reported perisylvian region involvement for both; however, their relationship and the linguistic information they harbor remain unknown. Participants were assessed by functional MRI, while spoken narratives (auditory) and written texts (visual) were presented, either separately or simultaneously. Participants were asked to attend to one stimulus when both were presented. We extracted phonemic and semantic features from these auditory and visual modalities, to train multiple, voxel-wise encoding models. Cross-modal examinations of the trained models revealed that perisylvian regions were associated with modality-invariant semantic representations. Attentional modulation was quantified by examining the modeling performance for attended and unattended conditions. We have determined that perisylvian regions exhibited attention selectivity. Both modality invariance and attention selectivity are both prominent in models that use semantic but not phonemic features. Modality invariance was significantly correlated with attention selectivity in some brain regions; however, we also identified cortical regions associated with only modality invariance or only attention selectivity. Thus, paying selective attention to a specific sensory input modality may regulate the semantic information that is partly processed in brain networks that are shared across modalities.

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Cochlear activity in silent cue-target intervals shows a theta-rhythmic pattern and is correlated to attentional alpha and theta modulations

BMC Biology ◽

10.1186/s12915-021-00992-8 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Moritz Herbert Albrecht Köhler ◽

Gianpaolo Demarchi ◽

Nathan Weisz

Keyword(s):

Selective Attention ◽

Brain Regions ◽

Attentional Focus ◽

Theta Activity ◽

Superior Olivary Complex ◽

Rhythmic Pattern ◽

Auditory Input ◽

Auditory Selective Attention ◽

Beta Power ◽

Cortical Regions

AbstractBackgroundA long-standing debate concerns where in the processing hierarchy of the central nervous system (CNS) selective attention takes effect. In the auditory system, cochlear processes can be influenced via direct and mediated (by the inferior colliculus) projections from the auditory cortex to the superior olivary complex (SOC). Studies illustrating attentional modulations of cochlear responses have so far been limited to sound-evoked responses. The aim of the present study is to investigate intermodal (audiovisual) selective attention in humans simultaneously at the cortical and cochlear level during a stimulus-free cue-target interval.ResultsWe found that cochlear activity in the silent cue-target intervals was modulated by a theta-rhythmic pattern (~ 6 Hz). While this pattern was present independently of attentional focus, cochlear theta activity was clearly enhanced when attending to the upcoming auditory input. On a cortical level, classical posterior alpha and beta power enhancements were found during auditory selective attention. Interestingly, participants with a stronger release of inhibition in auditory brain regions show a stronger attentional modulation of cochlear theta activity.ConclusionsThese results hint at a putative theta-rhythmic sampling of auditory input at the cochlear level. Furthermore, our results point to an interindividual variable engagement of efferent pathways in an attentional context that are linked to processes within and beyond processes in auditory cortical regions.

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A Multisensory fMRI Investigation of Nociceptive-Preferential Cortical Regions and Responses

Frontiers in Neuroscience ◽

10.3389/fnins.2021.635733 ◽

2021 ◽

Vol 15 ◽

Author(s):

Xiaoxia Zhang ◽

Linling Li ◽

Gan Huang ◽

Li Zhang ◽

Zhen Liang ◽

...

Keyword(s):

Sensory Input ◽

Sensory Stimulation ◽

Brain Regions ◽

Nociceptive Stimulation ◽

Functional Roles ◽

Sensory Modalities ◽

Cortical Regions ◽

Nociceptive Input ◽

Healthy Participants ◽

Different Parts

The existence of nociceptive-specific brain regions has been a controversial issue for decades. Multisensory fMRI studies, which examine fMRI activities in response to various types of sensory stimulation, could help identify nociceptive-specific brain regions, but previous studies are limited by sample size and they did not differentiate nociceptive-specific regions and nociceptive-preferential regions, which have significantly larger responses to nociceptive input. In this study, we conducted a multisensory fMRI experiment on 80 healthy participants, with the aim to determine whether there are certain brain regions that specifically or preferentially respond to nociceptive stimulation. By comparing the evoked fMRI responses across four sensory modalities, we found a series of brain regions specifically or preferentially involved in nociceptive sensory input. Particularly, we found different parts of some cortical regions, such as insula and cingulate gyrus, play different functional roles in the processing of nociceptive stimulation. Hence, this multisensory study improves our understanding of the functional integrations and segregations of the nociceptive-related regions.

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Hierarchical dynamics as a macroscopic organizing principle of the human brain

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2003383117 ◽

2020 ◽

Vol 117 (34) ◽

pp. 20890-20897 ◽

Cited By ~ 5

Author(s):

Ryan V. Raut ◽

Abraham Z. Snyder ◽

Marcus E. Raichle

Keyword(s):

Resting State ◽

Brain Function ◽

Large Scale ◽

Sensory Input ◽

Longitudinal Axis ◽

Brain Regions ◽

Human Cerebral Cortex ◽

Spatial Gradients ◽

Cortical Regions ◽

Multimodal Evidence

Multimodal evidence suggests that brain regions accumulate information over timescales that vary according to anatomical hierarchy. Thus, these experimentally defined “temporal receptive windows” are longest in cortical regions that are distant from sensory input. Interestingly, spontaneous activity in these regions also plays out over relatively slow timescales (i.e., exhibits slower temporal autocorrelation decay). These findings raise the possibility that hierarchical timescales represent an intrinsic organizing principle of brain function. Here, using resting-state functional MRI, we show that the timescale of ongoing dynamics follows hierarchical spatial gradients throughout human cerebral cortex. These intrinsic timescale gradients give rise to systematic frequency differences among large-scale cortical networks and predict individual-specific features of functional connectivity. Whole-brain coverage permitted us to further investigate the large-scale organization of subcortical dynamics. We show that cortical timescale gradients are topographically mirrored in striatum, thalamus, and cerebellum. Finally, timescales in the hippocampus followed a posterior-to-anterior gradient, corresponding to the longitudinal axis of increasing representational scale. Thus, hierarchical dynamics emerge as a global organizing principle of mammalian brains.

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Cochlear activity in silent cue-target intervals shows a theta-rhythmic pattern and is correlated to attentional alpha modulations

10.1101/653311 ◽

2019 ◽

Author(s):

Moritz Herbert Albrecht Köhler ◽

Gianpaolo Demarchi ◽

Nathan Weisz

Keyword(s):

Selective Attention ◽

Brain Regions ◽

Attentional Focus ◽

Theta Activity ◽

Superior Olivary Complex ◽

Rhythmic Pattern ◽

Auditory Input ◽

Auditory Selective Attention ◽

Beta Power ◽

Cortical Regions

AbstractA long-standing debate concerns where in the processing hierarchy of the central nervous system (CNS) selective attention takes effect. In the auditory system cochlear processes can be influenced via direct and mediated (by the inferior colliculus) projections from the auditory cortex to the superior olivary complex (SOC). Studies illustrating attentional modulations of cochlear responses have so far been limited to sound-evoked responses. The aim of the present study is to investigate intermodal (audiovisual) selective attention in humans simultaneously at the cortical and cochlear level during a stimulus-free cue-target period. We found that cochlear activity in the silent cue-target periods was modulated by a theta-rhythmic pattern (∼6 Hz). While this pattern was present independently of attentional focus, cochlear theta activity was clearly enhanced when attending to the upcoming auditory input. On a cortical level, classical posterior alpha and beta power enhancements were found during auditory selective attention. Interestingly, participants with a stronger release of inhibition in auditory brain regions show a stronger attentional modulation of cochlear theta activity. These results hint at a putative theta-rhythmic sampling of auditory input at the cochlear level. Furthermore, our results point to an interindividual variable engagement of efferent pathways in an attentional context that are linked to processes within and beyond processes in auditory cortical regions.

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Pregnancy-related changes in connections from the cervix to forebrain and hypothalamus in mice

Reproduction ◽

10.1530/rep-10-0002 ◽

2010 ◽

Vol 140 (1) ◽

pp. 155-164 ◽

Cited By ~ 2

Author(s):

Steven M Yellon ◽

Lauren A Grisham ◽

Genevieve M Rambau ◽

Thomas J Lechuga ◽

Michael A Kirby

Keyword(s):

Image Analysis ◽

Motor Cortex ◽

Paraventricular Nucleus ◽

Sensory Input ◽

Pseudorabies Virus ◽

Brain Regions ◽

Autonomic Functions ◽

Effector Functions ◽

Periventricular Nucleus ◽

Pregnant Mice

The transneuronal tracer pseudorabies virus was used to test the hypothesis that connections from the cervix to the forebrain and hypothalamus are maintained with pregnancy. The virus was injected into the cervix of nonpregnant or pregnant mice, and, after 5 days, virus-labeled cells and fibers were found in specific forebrain regions and, most prominently, in portions of the hypothalamic paraventricular nucleus. With pregnancy, fewer neurons and fibers were evident in most brain regions compared to that in nonpregnant mice. In particular, little or no virus was found in the medial and ventral parvocellular subdivisions, anteroventral periventricular nucleus, or motor cortex in pregnant mice. By contrast, labeling of virus was sustained in the dorsal hypothalamus and suprachiasmatic nucleus in all groups. Based upon image analysis of digitized photomicrographs, the area with label in the rostral and medial parvocellular paraventricular nucleus and magnocellular subdivisions was significantly reduced in mice whose cervix was injected with virus during pregnancy than in nonpregnant mice. The findings indicate that connections from the cervix to brain regions that are involved in sensory input and integrative autonomic functions are reduced during pregnancy. The findings raise the possibility that remaining pathways from the cervix to the forebrain and hypothalamus may be important for control of pituitary neuroendocrine secretion, as well as for effector functions in the cervix as pregnancy nears term.

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Structural and Functional MRI Brain Changes in Patients with Schizophrenia Following Electroconvulsive Therapy: A Systematic Review

Current Neuropharmacology ◽

10.2174/1570159x19666210809101248 ◽

2021 ◽

Vol 19 ◽

Author(s):

Yuchao Jiang ◽

Mingjun Duan ◽

Hui He ◽

Dezhong Yao ◽

Cheng Luo

Keyword(s):

Systematic Review ◽

Functional Mri ◽

Electroconvulsive Therapy ◽

Brain Regions ◽

Parahippocampal Gyrus ◽

Medical Subject Headings ◽

Therapeutic Mechanisms ◽

Brain Changes ◽

Meta Analyses ◽

Induced Changes

Background: Schizophrenia (SZ) is a severe psychiatric disorder typically characterized by multidimensional psychotic syndromes. Electroconvulsive therapy (ECT) is a treatment option for medication-resistant patients with SZ or to resolve acute symptoms. Although the efficacy of ECT has been demonstrated in clinical use, its therapeutic mechanisms in the brain remain elusive. Objective: This study aimed to summarize brain changes on structural magnetic resonance imaging (sMRI) and functional MRI (fMRI) after ECT. Methods: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was carried out. The PubMed and Medline databases were systematically searched using the following medical subject headings (MeSH): (electroconvulsive therapy OR ECT) AND (schizophrenia) AND (MRI OR fMRI OR DTI OR DWI). Results: This review yielded 12 MRI studies, including 4 with sMRI, 5 with fMRI and 3 with multimodal MRI. Increases in volumes of the hippocampus and its adjacent regions (parahippocampal gyrus and amygdala) as well as insula and frontotemporal regions were noted after ECT. fMRI studies found ECT-induced changes in different brain regions/networks, including the hippocampus, amygdala, default model network, salience network and other regions/networks that are thought to highly correlate with the pathophysiologic characteristics of SZ. The results of the correlation between brain changes and symptom remissions are inconsistent Conclusion: Our review provides evidence supporting ECT-induced brain changes on sMRI and fMRI in SZ and explores the relationship between these changes and symptom remission.

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Physical positioning markedly enhances brain transduction after intrathecal AAV9 infusion

Science Advances ◽

10.1126/sciadv.aau9859 ◽

2018 ◽

Vol 4 (11) ◽

pp. eaau9859 ◽

Cited By ~ 7

Author(s):

Michael J. Castle ◽

Yuhsiang Cheng ◽

Aravind Asokan ◽

Mark H. Tuszynski

Keyword(s):

Gene Expression ◽

Gene Delivery ◽

Neurological Disorders ◽

Fold Increase ◽

Brain Regions ◽

Intrathecal Administration ◽

Simple Method ◽

Virus Serotype ◽

Cortical Regions ◽

The Brain

Several neurological disorders may benefit from gene therapy. However, even when using the lead vector candidate for intrathecal administration, adeno-associated virus serotype 9 (AAV9), the strength and distribution of gene transfer to the brain are inconsistent. On the basis of preliminary observations that standard intrathecal AAV9 infusions predominantly drive reporter gene expression in brain regions where gravity might cause cerebrospinal fluid to settle, we tested the hypothesis that counteracting vector “settling” through animal positioning would enhance vector delivery to the brain. When rats are either inverted in the Trendelenburg position or continuously rotated after intrathecal AAV9 infusion, we find (i) a significant 15-fold increase in the number of transduced neurons, (ii) a marked increase in gene delivery to cortical regions, and (iii) superior animal-to-animal consistency of gene expression. Entorhinal, prefrontal, frontal, parietal, hippocampal, limbic, and basal forebrain neurons are extensively transduced: 95% of transduced cells are neurons, and greater than 70% are excitatory. These findings provide a novel and simple method for broad gene delivery to the cortex and are of substantial relevance to translational programs for neurological disorders, including Alzheimer’s disease and related dementias, stroke, and traumatic brain injury.

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Category representations in the brain are both discretely localized and widely distributed

Journal of Neurophysiology ◽

10.1152/jn.00912.2017 ◽

2018 ◽

Vol 119 (6) ◽

pp. 2256-2264 ◽

Cited By ~ 3

Author(s):

Zarrar Shehzad ◽

Gregory McCarthy

Keyword(s):

Functional Mri ◽

Brain Connectivity ◽

Strong Support ◽

Brain Regions ◽

Distributed Representations ◽

Domain Specific ◽

Category Information ◽

Shared Information ◽

Unique Domain ◽

The Brain

Whether category information is discretely localized or represented widely in the brain remains a contentious issue. Initial functional MRI studies supported the localizationist perspective that category information is represented in discrete brain regions. More recent fMRI studies using machine learning pattern classification techniques provide evidence for widespread distributed representations. However, these latter studies have not typically accounted for shared information. Here, we find strong support for distributed representations when brain regions are considered separately. However, localized representations are revealed by using analytical methods that separate unique from shared information among brain regions. The distributed nature of shared information and the localized nature of unique information suggest that brain connectivity may encourage spreading of information but category-specific computations are carried out in distinct domain-specific regions. NEW & NOTEWORTHY Whether visual category information is localized in unique domain-specific brain regions or distributed in many domain-general brain regions is hotly contested. We resolve this debate by using multivariate analyses to parse functional MRI signals from different brain regions into unique and shared variance. Our findings support elements of both models and show information is initially localized and then shared among other regions leading to distributed representations being observed.

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Hyper-attenuating brain lesions on CT after ischemic stroke and thrombectomy are associated with final brain infarction

Interventional Neuroradiology ◽

10.1177/1591019917729550 ◽

2017 ◽

Vol 23 (6) ◽

pp. 594-600 ◽

Cited By ~ 4

Author(s):

FB Cabral ◽

LH Castro-Afonso ◽

GS Nakiri ◽

LM Monsignore ◽

SRC Fábio ◽

...

Keyword(s):

Ischemic Stroke ◽

Endovascular Treatment ◽

Brain Infarction ◽

Internal Capsule ◽

Brain Regions ◽

Hemorrhagic Transformation ◽

Anterior Circulation ◽

Caudate Nuclei ◽

Predictive Values ◽

Cortical Regions

Purpose Hyper-attenuating lesions, or contrast staining, on a non-contrast brain computed tomography (NCCT) scan have been investigated as a predictor for hemorrhagic transformation after endovascular treatment of acute ischemic stroke (AIS). However, the association of hyper-attenuating lesions and final ischemic areas are poorly investigated in this setting. The aim of the present study was to assess correlations between hyper-attenuating lesions and final brain infarcted areas after thrombectomy for AIS. Methods Data from patients with AIS of the anterior circulation who underwent endovascular treatment were retrospectively assessed. Images of the brain NCCT scans were analyzed in the first hours and late after treatment. The hyper-attenuating areas were compared to the final ischemic areas using the Alberta Stroke Program Early CT Score (ASPECTS). Results Seventy-one of the 123 patients (65.13%) treated were included. The association between the hyper-attenuating region in the post-thrombectomy CT scan and final brain ischemic area were sensitivity (58.3% to 96.9%), specificity (42.9% to 95.6%), positive predictive values (71.4% to 97.7%), negative predictive values (53.8% to 79.5%), and accuracy values (68% to 91%). The highest sensitivity values were found for the lentiform (96.9%) and caudate nuclei (80.4%) and for the internal capsule (87.5%), and the lowest values were found for the M1 (58.3%) and M6 (66.7%) cortices. Conclusions Hyper-attenuating lesions on head NCCT scans performed after endovascular treatment of AIS may predict final brain infarcted areas. The prediction appears to be higher in the deep brain regions compared with the cortical regions.

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Fronto-striatal atrophy correlates of neuropsychiatric dysfunction in frontotemporal dementia (FTD) and Alzheimer's disease (AD)

Dementia & Neuropsychologia ◽

10.1590/s1980-57642013dn70100012 ◽

2013 ◽

Vol 7 (1) ◽

pp. 75-82 ◽

Cited By ~ 9

Author(s):

Dong Seok Yi ◽

Maxime Bertoux ◽

Eneida Mioshi ◽

John R. Hodges ◽

Michael Hornberger

Keyword(s):

Frontotemporal Dementia ◽

Rating Scale ◽

Brain Regions ◽

Abnormal Behaviour ◽

Behavioural Symptoms ◽

Visual Rating ◽

Prefrontal Cortical ◽

Mri Scans ◽

Visual Rating Scale ◽

Cortical Regions

ABSTRACT Behavioural disturbances in frontotemporal dementia (FTD) are thought to reflect mainly atrophy of cortical regions. Recent studies suggest that subcortical brain regions, in particular the striatum, are also significantly affected and this pathology might play a role in the generation of behavioural symptoms. Objective: To investigate prefrontal cortical and striatal atrophy contributions to behavioural symptoms in FTD. Methods: One hundred and eighty-two participants (87 FTD patients, 39 AD patients and 56 controls) were included. Behavioural profiles were established using the Cambridge Behavioural Inventory Revised (CBI-R) and Frontal System Behaviour Scale (FrSBe). Atrophy in prefrontal (VMPFC, DLPFC) and striatal (caudate, putamen) regions was established via a 5-point visual rating scale of the MRI scans. Behavioural scores were correlated with atrophy rating scores. Results: Behavioural and atrophy ratings demonstrated that patients were significantly impaired compared to controls, with bvFTD being most severely affected. Behavioural-anatomical correlations revealed that VMPFC atrophy was closely related to abnormal behaviour and motivation disturbances. Stereotypical behaviours were associated with both VMPFC and striatal atrophy. By contrast, disturbance of eating was found to be related to striatal atrophy only. Conclusion: Frontal and striatal atrophy contributed to the behavioural disturbances seen in FTD, with some behaviours related to frontal, striatal or combined fronto-striatal pathology. Consideration of striatal contributions to the generation of behavioural disturbances should be taken into account when assessing patients with potential FTD.

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