scholarly journals The physiological effects of noninvasive brain stimulation fundamentally differ across the human cortex

2020 ◽  
Vol 6 (5) ◽  
pp. eaay2739 ◽  
Author(s):  
Gabriel Castrillon ◽  
Nico Sollmann ◽  
Katarzyna Kurcyus ◽  
Adeel Razi ◽  
Sandro M. Krieg ◽  
...  
Keyword(s):  
Brain Stimulation ◽  
Large Scale ◽  
Functional Integration ◽  
Specific Effect ◽  
Occipital Cortex ◽  
Brain Regions ◽  
Biophysical Modeling ◽  
Network Parameter ◽  
Noninvasive Brain Stimulation ◽  
Local Inhibition

Transcranial magnetic stimulation (TMS) is a noninvasive method to modulate brain activity and behavior in humans. Still, stimulation effects substantially vary across studies and individuals, thereby restricting the large-scale application of TMS in research or clinical settings. We revealed that low-frequency stimulation had opposite impact on the functional connectivity of sensory and cognitive brain regions. Biophysical modeling then identified a neuronal mechanism underlying these region-specific effects. Stimulation of the frontal cortex decreased local inhibition and disrupted feedforward and feedback connections. Conversely, identical stimulation increased local inhibition and enhanced forward signaling in the occipital cortex. Last, we identified functional integration as a macroscale network parameter to predict the region-specific effect of stimulation in individual subjects. In summary, we revealed how TMS modulation critically depends on the connectivity profile of target regions and propose an imaging marker to improve sensitivity of noninvasive brain stimulation for research and clinical applications.

scholarly journals The physiological effects of non-invasive brain stimulation fundamentally differ across the human cortex

2019 ◽  
Author(s):  
Gabriel Castrillon ◽  
Nico Sollmann ◽  
Katarzyna Kurcyus ◽  
Adeel Razi ◽  
Sandro M. Krieg ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Brain Stimulation ◽  
Brain Activity ◽  
Functional Integration ◽  
Predictive Marker ◽  
Occipital Cortex ◽  
Brain Regions ◽  
Target Area ◽  
Biophysical Modeling ◽  
Non Invasive

AbstractNon-invasive brain stimulation reliably modulates brain activity and symptoms of neuropsychiatric disorders. However, stimulation effects substantially vary across individuals and brain regions. We combined transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) to investigate the neuronal basis of inter-individual and inter-areal differences after TMS. We found that stimulating sensory and cognitive areas yielded fundamentally heterogeneous effects. Stimulation of occipital cortex enhanced brain-wide functional connectivity and biophysical modeling identified increased local inhibition and enhanced forward-signaling after TMS. Conversely, frontal stimulation decreased functional connectivity, associated with local disinhibition and disruptions of both feedforward and feedback connections. Finally, we identified brain-wide functional integration as a predictive marker for these heterogeneous stimulation effects in individual subjects. Together, our study suggests that modeling of local and global signaling parameters of a target area will improve the specificity of non-invasive brain stimulation for research and clinical applications.

scholarly journals Large-scale functional integration, rather than functional dissociation along dorsal and ventral streams, underlies visual perception and action

2019 ◽  
Author(s):  
Dipanjan Ray ◽  
Nilambari Hajare ◽  
Dipanjan Roy ◽  
Arpan Banerjee
Keyword(s):  
Visual Perception ◽  
Large Scale ◽  
Premotor Cortex ◽  
Functional Integration ◽  
Predictive Coding ◽  
Dorsal Stream ◽  
Brain Regions ◽  
Neural Pathways ◽  
Healthy Human ◽  
Mri Environment

AbstractVisual dual stream theory posits that two distinct neural pathways of specific functional significance originate from primary visual areas and reach the inferior temporal (ventral) and posterior parietal areas (dorsal). However, there are several unresolved questions concerning the fundamental aspects of this theory. For example, is the functional dissociation between ventral and dorsal stream driven by features in input stimuli or is it driven by categorical differences between visuo-perceptual and visuo-motor functions? Is the dual stream rigid or flexible? What is the nature of the interactions between two streams? We addressed these questions using fMRI recordings on healthy human volunteers and employing stimuli and tasks that can tease out the divergence between visuo-perceptual and visuo-motor models of dual stream theory. fMRI scans were repeated after seven practice sessions that were conducted in a non-MRI environment to investigate the effects of neuroplasticity. Brain activation analysis supports an input-based functional dissociation and existence of context-dependent neuroplasticity in dual stream areas. Intriguingly, premotor cortex activation was observed in the position perception task and distributed deactivated regions were observed in all perception tasks thus, warranting a network level analysis. Dynamic causal modelling (DCM) analysis incorporating activated and deactivated brain areas during perception tasks indicates that the brain dynamics during visual perception and actions could be interpreted within the framework of predictive coding. Effectively, the network level findings point towards the existence of more intricate context-driven functional networks selective of “what” and “where” information rather than segregated streams of processing along ventral and dorsal brain regions.

scholarly journals Noninvasive Brain Stimulation and Psychotherapy in Anxiety and Depressive Disorders: A Viewpoint

2019 ◽  
Vol 9 (4) ◽  
pp. 82 ◽  
Author(s):  
Moussa Chalah ◽  
Samar Ayache
Keyword(s):  
Brain Stimulation ◽  
Large Scale ◽  
Depressive Disorders ◽  
Behavioral Therapy ◽  
Neuropsychiatric Symptoms ◽  
Clinical Settings ◽  
Noninvasive Brain Stimulation ◽  
Psychotherapeutic Interventions ◽  
Sham Intervention ◽  
New Treatments

Among the most prevalent psychiatric conditions stand anxiety and depression. Psychotherapy and medications are considered effective treatments in these clinical settings. However, pharmacotherapy and psychotherapy (i.e., cognitive behavioral therapy (CBT)) administered in monotherapy or in a combined regimen do not result in satisfactory outcomes in all patients. Therefore, finding new treatments would be of great help. In the last three decades, noninvasive brain stimulation (NIBS) has emerged as a safe tool to improve several neuropsychiatric symptoms. The following work revisits the available reports that assessed the add-on value of NIBS techniques when combined to psychotherapy (CBT or related interventions) in mood and anxiety disorders. The available protocols targeted the prefrontal cortex, a region that was previously found to have an enhanced activity or functional connectivity after psychotherapeutic interventions. Promising yet scarce evidence exists on this matter. A discrepancy exists among the available reports regarding the type and duration of interventions, the patients’ clinical profiles, and the presence of a sham intervention. NIBS may have acted by enhancing psychotherapy effects on the top-down cognitive control of emotions. Combining both therapies may result in promising effects, but future large-scale trials are needed to judge the utility of this combination in psychiatric populations.

scholarly journals Understanding diaschisis models of attention dysfunction with rTMS

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Javier O. Garcia ◽  
Lorella Battelli ◽  
Ela Plow ◽  
Zaira Cattaneo ◽  
Jean Vettel ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Brain Stimulation ◽  
Large Scale ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Low Frequency ◽  
Preliminary Evidence ◽  
Noninvasive Brain Stimulation ◽  
Induced Changes ◽  
Attention Dysfunction ◽  
The Impact

Abstract Visual attentive tracking requires a balance of excitation and inhibition across large-scale frontoparietal cortical networks. Using methods borrowed from network science, we characterize the induced changes in network dynamics following low frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) as an inhibitory noninvasive brain stimulation protocol delivered over the intraparietal sulcus. When participants engaged in visual tracking, we observed a highly stable network configuration of six distinct communities, each with characteristic properties in node dynamics. Stimulation to parietal cortex had no significant impact on the dynamics of the parietal community, which already exhibited increased flexibility and promiscuity relative to the other communities. The impact of rTMS, however, was apparent distal from the stimulation site in lateral prefrontal cortex. rTMS temporarily induced stronger allegiance within and between nodal motifs (increased recruitment and integration) in dorsolateral and ventrolateral prefrontal cortex, which returned to baseline levels within 15 min. These findings illustrate the distributed nature by which inhibitory rTMS perturbs network communities and is preliminary evidence for downstream cortical interactions when using noninvasive brain stimulation for behavioral augmentations.

scholarly journals Hemispheric Asymmetry of Human Brain Anatomical Network Revealed by Diffusion Tensor Tractography

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Ni Shu ◽  
Yaou Liu ◽  
Yunyun Duan ◽  
Kuncheng Li
Keyword(s):  
Human Brain ◽  
Large Scale ◽  
Diffusion Tensor ◽  
Functional Integration ◽  
Brain Regions ◽  
Hemispheric Asymmetries ◽  
Characteristic Path Length ◽  
Topological Measures ◽  
Structural Connections ◽  
The Brain

The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. However, few studies have investigated the hemispheric asymmetries of the human brain from the perspective of the network model, and little is known about the asymmetries of the connection patterns of brain regions, which may reflect the functional integration and interaction between different regions. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 72 right-handed healthy adult subjects. We established the existence of structural connections between any pair of the 90 cortical and subcortical regions using deterministic tractography. To investigate the hemispheric asymmetries of the brain, statistical analyses were performed to reveal the brain regions with significant differences between bilateral topological properties, such as degree of connectivity, characteristic path length, and betweenness centrality. Furthermore, local structural connections were also investigated to examine the local asymmetries of some specific white matter tracts. From the perspective of both the global and local connection patterns, we identified the brain regions with hemispheric asymmetries. Combined with the previous studies, we suggested that the topological asymmetries in the anatomical network may reflect the functional lateralization of the human brain.

scholarly journals Large-scale Functional Integration, Rather than Functional Dissociation along Dorsal and Ventral Streams, Underlies Visual Perception and Action

2020 ◽  
Vol 32 (5) ◽  
pp. 847-861 ◽  
Author(s):  
Dipanjan Ray ◽  
Nilambari Hajare ◽  
Dipanjan Roy ◽  
Arpan Banerjee
Keyword(s):  
Visual Perception ◽  
Large Scale ◽  
Premotor Cortex ◽  
Functional Integration ◽  
Predictive Coding ◽  
Dorsal Stream ◽  
Brain Regions ◽  
Causal Modeling ◽  
Neural Pathways ◽  
Healthy Human

Visual dual-stream theory posits that two distinct neural pathways of specific functional significance originate from primary visual areas and reach the inferior temporal (ventral) and posterior parietal areas (dorsal). However, there are several unresolved questions concerning the fundamental aspects of this theory. For example, is the functional dissociation between ventral and dorsal stream driven by features in input stimuli or is it driven by categorical differences between visuoperceptual and visuomotor functions? Is the dual stream rigid or flexible? What is the nature of the interactions between the two streams? We addressed these questions using fMRI recordings on healthy human volunteers and employing stimuli and tasks that can tease out the divergence between visuoperceptual and visuomotor variants of dual-stream theory. fMRI scans were repeated after seven practice sessions that were conducted in a non-MRI environment to investigate the effects of neuroplasticity. Brain activation analysis supports an input-based functional dissociation and existence of context-dependent neuroplasticity in dual-stream areas. Intriguingly, premotor cortex activation was observed in the position perception task and distributed deactivated regions were observed in all perception tasks, thus warranting a network-level analysis. Dynamic causal modeling analysis incorporating activated and deactivated brain areas during perception tasks indicates that the brain dynamics during visual perception and actions could be interpreted within the framework of predictive coding. Effectively, the network-level findings point toward the existence of more intricate context-driven functional networks selective of “what” and “where” information rather than segregated streams of processing along ventral and dorsal brain regions.

scholarly journals Intracranial brain stimulation modulates fMRI-based network switching

2021 ◽  
Author(s):  
Mangor Pedersen ◽  
Andrew Zalesky
Keyword(s):  
Clinical Efficacy ◽  
Brain Stimulation ◽  
Large Scale ◽  
Brain Networks ◽  
Network Models ◽  
Brain Regions ◽  
Brain Network ◽  
Intracranial Stimulation ◽  
List Type ◽  
Network Modelling

SummaryThe extent to which resting-state fMRI (rsfMRI) reflects direct neuronal changes remains unknown. Using 160 simultaneous rsfMRI and intracranial brain stimulation recordings acquired in 26 individuals with epilepsy (with varying electrode locations), we tested whether brain networks dynamically change during intracranial brain stimulation, aiming to establish whether switching between brain networks is reduced during intracranial brain stimulation. As the brain spontaneously switches between a repertoire of intrinsic functional network configurations and the rate of switching is typically increased in brain disorders, we hypothesised that intracranial stimulation would reduce the brain’s switching rate, thus potentially normalising aberrant brain network dynamics. To test this hypothesis, we quantified the rate that brain regions changed networks over time in response to brain stimulation, using network switching applied to multilayer modularity analysis of time-resolved rsfMRI connectivity. Network switching was significantly decreased during epochs with brain stimulation compared to epochs with no brain stimulation. The initial stimulation onset of brain stimulation was associated with the greatest decrease in network switching, followed by a more consistent reduction in network switching throughout the scans. These changes were most commonly observed in cortical networks spatially distant from the stimulation targets. Our results suggest that neuronal perturbation is likely to modulate large-scale brain networks, and multilayer network modelling may be used to inform the clinical efficacy of brain stimulation in neurological disease.HighlightsrsfMRI network switching is attenuated during intracranial brain stimulationStimulation-induced switching is observed distant from electrode targetsOur results are validated across a range of network parametersNetwork models may inform clinical efficacy of brain stimulation

Elucidating and Modulating the Neural Correlates of Visuospatial Working Memory via Noninvasive Brain Stimulation

2017 ◽  
Vol 26 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Chi-Hung Juan ◽  
Philip Tseng ◽  
Tzu-Yu Hsu
Keyword(s):  
Working Memory ◽  
Brain Stimulation ◽  
Visual Information ◽  
Posterior Parietal Cortex ◽  
Short Term Memory ◽  
Brain Regions ◽  
Visuospatial Working Memory ◽  
Noninvasive Brain Stimulation ◽  
Memory Mechanism ◽  
Posterior Parietal

Visuospatial working memory refers to the short-term memory mechanism that enables humans to remember visual information across visual blackout periods such as eyeblinks or eye movements. In recent years, neuroscientific studies have made great progress in uncovering the brain regions that support visuospatial working memory. In this review, we focus on the role of the posterior parietal cortex in forming and maintaining visual information, and use it as an example to highlight how noninvasive brain-stimulation techniques, particularly transcranial magnetic, direct current, and alternating current stimulation, can shed light on this topic because of their unique strengths in modulating brain activities.

Noninvasive Brain Stimulation: Contribution to Research in Neuroaesthetics

2020 ◽  
Author(s):  
Zaira Cattaneo
Keyword(s):  
Brain Stimulation ◽  
Brain Regions ◽  
Transcranial Electrical Stimulation ◽  
Noninvasive Brain Stimulation ◽  
Aesthetic Experiences ◽  
Non Invasive ◽  
Future Potential ◽  
Brain Behavior ◽  
Shed Light

Noninvasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES), are largely employed in cognitive neuroscience to investigate the brain–behavior relationship. During the last decade, non-invasive brain stimulation techniques have been increasingly employed in the field of neuroaesthetics research to shed light on the possible causal role of different brain regions contributing to aesthetic appreciation. This chapter provides a synthetic description of mechanisms of actions of TMS and different types of tES, and reviews recent NIBS studies that have shed light on the neural underpinning of aesthetic evaluation of (visual) artworks. The chapter also considers methodological limitations of the reviewed studies and the future potential for non-invasive brain stimulation to significantly contribute to the understanding of the neural bases of visual aesthetic experiences.

scholarly journals The universal language network: A cross-linguistic investigation spanning 45 languages and 11 language families.

2021 ◽  
Author(s):  
Dima Ayyash ◽  
Saima Malik-Moraleda ◽  
Jeanne Gallee ◽  
Josef Affourtit ◽  
Malte Hoffman ◽  
...  
Keyword(s):  
Language Processing ◽  
Cognitive Neuroscience ◽  
Large Scale ◽  
Functional Integration ◽  
Brain Regions ◽  
European Languages ◽  
Universal Language ◽  
Neuroscience Research ◽  
Temporal Language ◽  
Language Network

To understand the architecture of human language, it is critical to examine diverse languages; yet most cognitive neuroscience research has focused on a handful of primarily Indo-European languages. Here, we report a large-scale investigation of the fronto-temporal language network across 45 languages and establish the cross-linguistic generality of its key functional properties, including general topography, left-lateralization, strong functional integration among its brain regions, and functional selectivity for language processing. 

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