scholarly journals Event-related network changes unfold the dynamics of cortical integration during face processing

2020 ◽  
Author(s):  
Antonio Maffei ◽  
Paola Sessa
Keyword(s):  
Face Perception ◽  
Network Topology ◽  
Face Processing ◽  
Visual Processing ◽  
Network Architecture ◽  
Time Window ◽  
Brain Regions ◽  
Data Availability ◽  
Global Network ◽  
State And Local

AbstractFace perception arises from a collective activation of brain regions in the occipital, parietal and temporal cortices. Despite wide acknowledgement that these regions act in an intertwined network, the network behavior itself is poorly understood. Here we present a study in which time-varying connectivity estimated from EEG activity elicited by facial expressions presentation was characterized using graph-theoretical measures of node centrality and global network topology. Results revealed that face perception results from a dynamic reshaping of the network architecture, characterized by the emergence of hubs located in the occipital and temporal regions of the scalp. The importance of these nodes can be observed from early stages of visual processing and reaches a climax in the same time-window in which the face-sensitive N170 is observed. Furthermore, using Granger causality, we found that the time-evolving centrality of these nodes is associated with ERP amplitude, providing a direct link between the network state and local neural response. Additionally, investigating global network topology by means of small-worldness and modularity, we found that face processing requires a functional network with a strong small-world organization that maximizes integration, at the cost of segregated subdivisions. Interestingly, we found that this architecture is not static, but instead it is implemented by the network from stimulus onset to ~200 msec. Altogether, this study reveals the event-related changes underlying face processing at the network level, suggesting that a distributed processing mechanism operates through dynamically weighting the contribution of the cortical regions involved.Data AvailabilityData and code related to this manuscript can be accessed through the OSF at this link https://osf.io/hc3sk/?view_only=af52bc4295c044ffbbd3be019cc083f4

scholarly journals Effect of Brightness of Visual Stimuli on EEG Signals

2019 ◽  
Author(s):  
Kübra Eroğlu ◽  
Temel Kayıkçıoğlu ◽  
Onur Osman
Keyword(s):  
Visual Processing ◽  
Time Window ◽  
Time Windows ◽  
Visual Stimuli ◽  
Average Power ◽  
Power Spectra ◽  
Brain Regions ◽  
Behavioral Data ◽  
Brain Responses ◽  
The Brain

The aim of this study was to examine brightness effect, which is the perceptual property of visual stimuli, on brain responses obtained during visual processing of these stimuli. For this purpose, brain responses of the brain to changes in brightness were explored comparatively using different emotional images (pleasant, unpleasant and neutral) with different luminance levels. Moreover, electroencephalography recordings from 12 different electrode sites of 31 healthy participants were used. The power spectra obtained from the analysis of the recordings using short time Fourier transform were analyzed, and a statistical analysis was performed on features extracted from these power spectra. Statistical findings obtained from electrophysiological data were compared with those obtained from behavioral data. The results showed that the brightness of visual stimuli affected the power of brain responses depending on frequency, time and location. According to the statistically verified findings, the distinctive effect of brightness occurred in the parietal and occipital regions for all the three types of stimuli. Accordingly, the increase in the brightness of pleasant and neutral images increased the average power of responses in the parietal and occipital regions whereas the increase in the brightness of unpleasant images decreased the average power of responses in these regions. However, the increase in brightness for all the three types of stimuli reduced the average power of frontal and central region responses (except for 100-300 ms time window for unpleasant stimuli). The statistical results obtained for unpleasant images were found to be in accordance with the behavioral data. The results also revealed that the brightness of visual stimuli could be represented by changing the activity power of the brain cortex. The main contribution of this research was to comprehensively examine brightness effect on brain activity for images with different emotional content and different frequency bands at different time windows of visual processing for different brain regions. The findings emphasized that the brightness of visual stimuli should be viewed as an important parameter in studies using emotional image techniques such as image classification, emotion evaluation and neuro-marketing.

scholarly journals Functional selectivity for face processing in the temporal voice area of early deaf individuals

2017 ◽  
Author(s):  
Stefania Benetti ◽  
Markus J. van Ackeren ◽  
Giuseppe Rabini ◽  
Joshua Zonca ◽  
Valentina Foa ◽  
...  
Keyword(s):  
Face Processing ◽  
Visual Processing ◽  
Effective Connectivity ◽  
Sensory Deprivation ◽  
Brain Regions ◽  
Voice Perception ◽  
Temporal Area ◽  
Profound Deafness ◽  
The Face ◽  
Voice Processing

AbstractBrain systems supporting face and voice processing both contribute to the extraction of important information for social interaction (e.g., person identity). How does the brain reorganize when one of these channels is absent? Here we explore this question by combining behavioral and multimodal neuroimaging measures (magneto-encephalography and functional imaging) in a group of early deaf humans. We show enhanced selective neural response for faces and for individual face coding in a specific region of the auditory cortex that is typically specialized for voice perception in hearing individuals. In this region, selectivity to face signals emerges early in the visual processing hierarchy, shortly following typical face-selective responses in the ventral visual pathway. Functional and effective connectivity analyses suggest reorganization in long-range connections from early visual areas to the face-selective temporal area in individuals with early and profound deafness. Altogether, these observations demonstrate that regions that typically specialize for voice processing in the hearing brain preferentially reorganize for face processing in born deaf people. Our results support the idea that cross-modal plasticity in case of early sensory deprivation relates to the original functional specialization of the reorganized brain regions.

scholarly journals Spatiotemporal ontogeny of brain wiring

2019 ◽  
Vol 5 (6) ◽  
pp. eaav9694 ◽  
Author(s):  
A. Goulas ◽  
R. F. Betzel ◽  
C. C. Hilgetag
Keyword(s):  
Computational Modeling ◽  
Network Topology ◽  
Brain Regions ◽  
Adult Brain ◽  
Axonal Guidance ◽  
Global Network ◽  
Dependent Plasticity ◽  
Guidance Cues ◽  
And Behavior ◽  
Activity Dependent

The wiring of vertebrate and invertebrate brains provides the anatomical skeleton for cognition and behavior. Connections among brain regions are characterized by heterogeneous strength that is parsimoniously described by the wiring cost and homophily principles. Moreover, brains exhibit a characteristic global network topology, including modules and hubs. However, the mechanisms resulting in the observed interregional wiring principles and network topology of brains are unknown. Here, with the aid of computational modeling, we demonstrate that a mechanism based on heterochronous and spatially ordered neurodevelopmental gradients, without the involvement of activity-dependent plasticity or axonal guidance cues, can reconstruct a large part of the wiring principles (on average, 83%) and global network topology (on average, 80%) of diverse adult brain connectomes, including fly and human connectomes. In sum, space and time are key components of a parsimonious, plausible neurodevelopmental mechanism of brain wiring with a potential universal scope, encompassing vertebrate and invertebrate brains.

A Perceptual Traffic Jam on Highway N170

2005 ◽  
Vol 14 (1) ◽  
pp. 30-33 ◽  
Author(s):  
Isabel Gauthier ◽  
Kim M. Curby
Keyword(s):  
Object Recognition ◽  
Face Perception ◽  
Face Processing ◽  
Direct Evidence ◽  
Brain Activation ◽  
Brain Regions ◽  
Behavioral Performance ◽  
Traffic Jam ◽  
Rule Out

Whether face processing is modular or not has been the topic of a lively empirical and theoretical debate. In expert observers, the perception of nonface objects in their domain of expertise is remarkably similar to their perception of faces, in patterns of both behavioral performance and brain activation, providing some evidence against the modularity of face perception. However, the studies that have yielded these results do not rule out the possibility that object expertise and face processing occur in spatially overlapping, but functionally independent, brain regions. Recent research using an interference paradigm reveals that expert object (car) processing interferes with face processing. The level of interference was proportional to an individual's level of car expertise. These results may provide the most direct evidence to date that face and object recognition are not functionally independent.

scholarly journals Delineating Neural Responses and Functional Connectivity Changes During Vestibular and Nociceptive Stimulation Reveal the Uniqueness of Cortical Vestibular Processing

2021 ◽  
Author(s):  
Judita Huber ◽  
Ria Maxine Rühl ◽  
Virginia Flanagin ◽  
Peter zu Eulenburg
Keyword(s):  
Network Architecture ◽  
Vestibular Stimulation ◽  
Brain Regions ◽  
Global Network ◽  
Proprioceptive Information ◽  
Nociceptive Stimulation ◽  
Vestibular Information ◽  
Nociceptive Responses ◽  
Vestibular Perception ◽  
Heterogeneous Region

Abstract Vestibular information is ubiquitous and often processed jointly with visual, somatosensory and proprioceptive information. Among the cortical brain regions associated with human vestibular processing, area OP2 in the parietal operculum has been proposed as vestibular core region. However, delineating responses uniquely to vestibular stimulation in this region using neuroimaging is challenging for several reasons: Firstly, the parietal operculum is a cytoarchitectonically heterogeneous region responding to multisensory stimulation. Secondly, artificial vestibular stimulation evokes confounding somatosensory and nociceptive responses blurring responses contributing to vestibular perception. Furthermore, immediate effects of vestibular stimulation on the organization of functional networks have not been investigated in detail yet.Here, we compared two equally salient stimuli - galvanic vestibular stimulation (GVS) and galvanic nociceptive stimulation (GNS)- to disentangle the processing of both modalities in the parietal operculum and characterize their effects on functional network architecture. GNS and GVS gave joint responses in area OP1,3,4, and the anterior and middle insula, but not in area OP2. Contrasting both stimulation modalities resulted in stronger responses in parts of the parietal operculum adjacent to OP3 and OP4 during GVS, whereas GNS evoked stronger responses in area OP1,3 and 4. Our results underline the importance of considering this common multisensory trunk when interpreting vestibular neuroimaging experiments and further underpin the role of area OP2 in central vestibular processing. Global network changes were found during GNS, but not during GVS. This lack of network reconfiguration despite the saliency of GVS may reflect the continuous processing of vestibular information in the awake human.

scholarly journals Delineating neural responses and functional connectivity changes during vestibular and nociceptive stimulation reveal the uniqueness of cortical vestibular processing

2021 ◽  
Author(s):  
Judita Huber ◽  
Maxine Ruehl ◽  
Virginia Flanagin ◽  
Peter zu Eulenburg
Keyword(s):  
Functional Connectivity ◽  
Network Architecture ◽  
Vestibular Stimulation ◽  
Brain Regions ◽  
Global Network ◽  
Proprioceptive Information ◽  
Nociceptive Stimulation ◽  
Vestibular Information ◽  
Nociceptive Responses ◽  
Vestibular Perception

AbstractVestibular information is ubiquitous and often processed jointly with visual, somatosensory and proprioceptive information. Among the cortical brain regions associated with human vestibular processing, area OP2 in the parietal operculum has been proposed as vestibular core region. However, delineating responses uniquely to vestibular stimulation in this region using neuroimaging is challenging for several reasons: First, the parietal operculum is a cytoarchitectonically heterogeneous region responding to multisensory stimulation. Second, artificial vestibular stimulation evokes confounding somatosensory and nociceptive responses blurring responses contributing to vestibular perception. Furthermore, immediate effects of vestibular stimulation on the organization of functional networks have not been investigated in detail yet. Using high resolution neuroimaging in a task-based and functional connectivity approach, we compared two equally salient stimuli—unilateral galvanic vestibular (GVS) and galvanic nociceptive stimulation (GNS)—to disentangle the processing of both modalities in the parietal operculum and characterize their effects on functional network architecture. GNS and GVS gave joint responses in area OP1, 3, 4, and the anterior and middle insula, but not in area OP2. GVS gave stronger responses in the parietal operculum just adjacent to OP3 and OP4, whereas GNS evoked stronger responses in area OP1, 3 and 4. Our results underline the importance of considering this common pathway when interpreting vestibular neuroimaging experiments and underpin the role of area OP2 in central vestibular processing. Global network changes were found during GNS, but not during GVS. This lack of network reconfiguration despite the saliency of GVS may reflect the continuous processing of vestibular information in the awake human.

scholarly journals Neuron Geometry Underlies Universal Network Features in Cortical Microcircuits

2019 ◽  
Author(s):  
Eyal Gal ◽  
Rodrigo Perin ◽  
Henry Markram ◽  
Michael London ◽  
Idan Segev
Keyword(s):  
Network Architecture ◽  
Brain Regions ◽  
Global Network ◽  
Local Geometry ◽  
Network Motifs ◽  
Neuron Network ◽  
Spatial Alignment ◽  
Cortical Microcircuits ◽  
General Network

ABSTRACTWhy do cortical microcircuits in a variety of brain regions express similar, highly nonrandom, network motifs? To what extent this structure is innate and how much of it is molded by plasticity and learning processes? To address these questions, we developed a general network science framework to quantify the contribution of neurons’ geometry and their embedding in cortical volume to the emergence of three-neuron network motifs. Applying this framework to a dense in silico reconstructed cortical microcircuits showed that the innate asymmetric neuron’s geometry underlies the universally recurring motif architecture. It also predicted the spatial alignment of cells composing the different triplets-motifs. These predictions were directly validated via in vitro 12-patch whole-cell recordings (7,309 triplets) from rat somatosensory cortex. We conclude that the local geometry of neurons imposes an innate, already structured, global network architecture, which serves as a skeleton upon which fine-grained structural and functional plasticity processes take place.

scholarly journals Special Patterns of Dynamic Brain Networks Discriminate Between Face and Non-face Processing: A Single-Trial EEG Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Zhongliang Yin ◽  
Yue Wang ◽  
Minghao Dong ◽  
Shenghan Ren ◽  
Haihong Hu ◽  
...  
Keyword(s):  
Human Brain ◽  
Face Processing ◽  
Information Transfer ◽  
Minimum Spanning Tree ◽  
Time Window ◽  
Time Windows ◽  
Brain Networks ◽  
Brain Regions ◽  
Brain Network ◽  
The Face

Face processing is a spatiotemporal dynamic process involving widely distributed and closely connected brain regions. Although previous studies have examined the topological differences in brain networks between face and non-face processing, the time-varying patterns at different processing stages have not been fully characterized. In this study, dynamic brain networks were used to explore the mechanism of face processing in human brain. We constructed a set of brain networks based on consecutive short EEG segments recorded during face and non-face (ketch) processing respectively, and analyzed the topological characteristic of these brain networks by graph theory. We found that the topological differences of the backbone of original brain networks (the minimum spanning tree, MST) between face and ketch processing changed dynamically. Specifically, during face processing, the MST was more line-like over alpha band in 0–100 ms time window after stimuli onset, and more star-like over theta and alpha bands in 100–200 and 200–300 ms time windows. The results indicated that the brain network was more efficient for information transfer and exchange during face processing compared with non-face processing. In the MST, the nodes with significant differences of betweenness centrality and degree were mainly located in the left frontal area and ventral visual pathway, which were involved in the face-related regions. In addition, the special MST patterns can discriminate between face and ketch processing by an accuracy of 93.39%. Our results suggested that special MST structures of dynamic brain networks reflected the potential mechanism of face processing in human brain.

scholarly journals Functional selectivity for face processing in the temporal voice area of early deaf individuals

2017 ◽  
Vol 114 (31) ◽  
pp. E6437-E6446 ◽  
Author(s):  
Stefania Benetti ◽  
Markus J. van Ackeren ◽  
Giuseppe Rabini ◽  
Joshua Zonca ◽  
Valentina Foa ◽  
...  
Keyword(s):  
Face Processing ◽  
Visual Processing ◽  
Effective Connectivity ◽  
Sensory Deprivation ◽  
Brain Regions ◽  
Voice Perception ◽  
Temporal Area ◽  
Profound Deafness ◽  
The Face ◽  
Voice Processing

Brain systems supporting face and voice processing both contribute to the extraction of important information for social interaction (e.g., person identity). How does the brain reorganize when one of these channels is absent? Here, we explore this question by combining behavioral and multimodal neuroimaging measures (magneto-encephalography and functional imaging) in a group of early deaf humans. We show enhanced selective neural response for faces and for individual face coding in a specific region of the auditory cortex that is typically specialized for voice perception in hearing individuals. In this region, selectivity to face signals emerges early in the visual processing hierarchy, shortly after typical face-selective responses in the ventral visual pathway. Functional and effective connectivity analyses suggest reorganization in long-range connections from early visual areas to the face-selective temporal area in individuals with early and profound deafness. Altogether, these observations demonstrate that regions that typically specialize for voice processing in the hearing brain preferentially reorganize for face processing in born-deaf people. Our results support the idea that cross-modal plasticity in the case of early sensory deprivation relates to the original functional specialization of the reorganized brain regions.

scholarly journals Spatiotemporal ontogeny of brain wiring

2018 ◽  
Author(s):  
Alexandros Goulas ◽  
Richard F. Betzel ◽  
Claus C. Hilgetag
Keyword(s):  
Network Topology ◽  
Short Path ◽  
Brain Regions ◽  
Adult Brain ◽  
Axonal Guidance ◽  
Global Network ◽  
Path Lengths ◽  
And Behavior ◽  
Activity Dependent ◽  
The Brain

AbstractThe wiring of the brain provides the anatomical skeleton for cognition and behavior. Connections among brain regions have a diverse and characteristic strength. This strength heterogeneity is captured by the wiring cost and homophily principles. Moreover, brains have a characteristic global network topology, including modularity and short path lengths. However, the mechanisms underlying the inter-regional wiring principles and global network topology of brains are unknown. Here, we address this issue by modeling the ontogeny of brain connectomes. We demonstrate that spatially embedded and heterochronous neurogenetic gradients, without the need of axonal-guidance molecules or activity-dependent plasticity, can reconstruct the wiring principles and shape the global network topology observed in adult brain connectomes. Thus, two fundamental dimensions, that is, space and time, are key components of a plausible neurodevelopmental mechanism with a universal scope, encompassing vertebrate and invertebrate brains.

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