scholarly journals Fast temporal dynamics and causal relevance of face processing in the human temporal cortex

2018 ◽  
Author(s):  
Jessica Schrouff ◽  
Omri Raccah ◽  
Sori Baek ◽  
Vinitha Rangarajan ◽  
Sina Salehi ◽  
...  
Keyword(s):  
Human Brain ◽  
Face Processing ◽  
Common Ground ◽  
Temporal Dynamics ◽  
Time Window ◽  
Temporal Cortex ◽  
Surrogate Marker ◽  
Marine Animal ◽  
Distributed Models ◽  
Spatio Temporal

ABSTRACTRecordings with a large number of intracranial electrodes in eight neurosurgical subjects offered a unique opportunity to examine the fast temporal dynamics of face processing simultaneously across a relatively large extent of the human temporal cortex (TC). Measuring the power of slow oscillatory bands of activity (θ, α, β, and γ) as well as High-Frequency Broadband (HFB, 70-177 Hz) signal, we found that the HFB showed the strongest univariate and multivariate changes in response to face compared to non-face stimuli. Using the HFB signal as a surrogate marker for local cortical engagement, we identified recording sites with selective responses to faces that were anatomically consistent across subjects and responded with graded strength to human, mammal, bird, and marine animal faces. Importantly, the most face selective sites were located more posteriorly and responded earlier than those with less selective responses to faces. Using machine learning based methods, we demonstrated that a sparse model focusing on information from the human face selective sites performed as well as, or better than, anatomically distributed models of face processing when discriminating faces from non-faces stimuli. Lastly, we identified the posterior fusiform (pFUS) site as causally the most relevant node for inducing distortion of face perception by direct electrical stimulation. Our findings support the notion of face information being processed first in the most selective sites - that are anatomically discrete and localizable within individual brains and anatomically consistent across subjects – which is then distributed in time to less selective anterior temporal sites within a time window that is too fast to be detected by current neuroimaging methods. The new information about the fast spatio-temporal dynamics of face processing across multiple sites of the human brain provides a new common ground for unifying the seemingly contradictory modular and distributed models of face processing in the human brain.

scholarly journals STAB: a spatio-temporal cell atlas of the human brain

2020 ◽  
Vol 49 (D1) ◽  
pp. D1029-D1037
Author(s):  
Liting Song ◽  
Shaojun Pan ◽  
Zichao Zhang ◽  
Longhao Jia ◽  
Wei-Hua Chen ◽  
...  
Keyword(s):  
Human Brain ◽  
Single Cell ◽  
Temporal Dynamics ◽  
Cell Types ◽  
Brain Regions ◽  
Molecular Characteristics ◽  
Great Effort ◽  
Brain Functions ◽  
Spatio Temporal ◽  
The Brain

Abstract The human brain is the most complex organ consisting of billions of neuronal and non-neuronal cells that are organized into distinct anatomical and functional regions. Elucidating the cellular and transcriptome architecture underlying the brain is crucial for understanding brain functions and brain disorders. Thanks to the single-cell RNA sequencing technologies, it is becoming possible to dissect the cellular compositions of the brain. Although great effort has been made to explore the transcriptome architecture of the human brain, a comprehensive database with dynamic cellular compositions and molecular characteristics of the human brain during the lifespan is still not available. Here, we present STAB (a Spatio-Temporal cell Atlas of the human Brain), a database consists of single-cell transcriptomes across multiple brain regions and developmental periods. Right now, STAB contains single-cell gene expression profiling of 42 cell subtypes across 20 brain regions and 11 developmental periods. With STAB, the landscape of cell types and their regional heterogeneity and temporal dynamics across the human brain can be clearly seen, which can help to understand both the development of the normal human brain and the etiology of neuropsychiatric disorders. STAB is available at http://stab.comp-sysbio.org.

Dynamic Changes in the Mental Rotation Network Revealed by Pattern Recognition Analysis of fMRI Data

2009 ◽  
Vol 21 (5) ◽  
pp. 890-904 ◽  
Author(s):  
Janaina Mourao-Miranda ◽  
Christine Ecker ◽  
Joao R. Sato ◽  
Michael Brammer
Keyword(s):  
Pattern Recognition ◽  
Functional Connectivity ◽  
Mental Rotation ◽  
Temporal Dynamics ◽  
Parietal Lobe ◽  
Time Window ◽  
Support Vector ◽  
Dynamic Changes ◽  
Angular Disparity ◽  
Spatio Temporal

We investigated the temporal dynamics and changes in connectivity in the mental rotation network through the application of spatio-temporal support vector machines (SVMs). The spatio-temporal SVM [Mourao-Miranda, J., Friston, K. J., et al. (2007). Dynamic discrimination analysis: A spatial-temporal SVM. Neuroimage, 36, 88–99] is a pattern recognition approach that is suitable for investigating dynamic changes in the brain network during a complex mental task. It does not require a model describing each component of the task and the precise shape of the BOLD impulse response. By defining a time window including a cognitive event, one can use spatio-temporal fMRI observations from two cognitive states to train the SVM. During the training, the SVM finds the discriminating pattern between the two states and produces a discriminating weight vector encompassing both voxels and time (i.e., spatio-temporal maps). We showed that by applying spatio-temporal SVM to an event-related mental rotation experiment, it is possible to discriminate between different degrees of angular disparity (0° vs. 20°, 0° vs. 60°, and 0° vs. 100°), and the discrimination accuracy is correlated with the difference in angular disparity between the conditions. For the comparison with highest accuracy (0° vs. 100°), we evaluated how the most discriminating areas (visual regions, parietal regions, supplementary, and premotor areas) change their behavior over time. The frontal premotor regions became highly discriminating earlier than the superior parietal cortex. There seems to be a parcellation of the parietal regions with an earlier discrimination of the inferior parietal lobe in the mental rotation in relation to the superior parietal. The SVM also identified a network of regions that had a decrease in BOLD responses during the 100° condition in relation to the 0° condition (posterior cingulate, frontal, and superior temporal gyrus). This network was also highly discriminating between the two conditions. In addition, we investigated changes in functional connectivity between the most discriminating areas identified by the spatio-temporal SVM. We observed an increase in functional connectivity between almost all areas activated during the 100° condition (bilateral inferior and superior parietal lobe, bilateral premotor area, and SMA) but not between the areas that showed a decrease in BOLD response during the 100° condition.

Spatio–temporal dynamics of olfactory processing in the human brain: an event-related source imaging study

Neuroscience ◽  
2010 ◽  
Vol 167 (3) ◽  
pp. 700-708 ◽  
Author(s):  
A.M. Lascano ◽  
T. Hummel ◽  
J.-S. Lacroix ◽  
B.N. Landis ◽  
C.M. Michel
Keyword(s):  
Human Brain ◽  
Temporal Dynamics ◽  
Imaging Study ◽  
Source Imaging ◽  
Olfactory Processing ◽  
Spatio Temporal

Spatio-temporal dynamics of kind versus hostile intentions in the human brain: An electrical neuroimaging study

2014 ◽  
Vol 10 (3) ◽  
pp. 253-267 ◽  
Author(s):  
Yiwen Wang ◽  
Liang Huang ◽  
Wei Zhang ◽  
Zhen Zhang ◽  
Stephanie Cacioppo
Keyword(s):  
Human Brain ◽  
Temporal Dynamics ◽  
Electrical Neuroimaging ◽  
Neuroimaging Study ◽  
Spatio Temporal

scholarly journals Isolating syntax in natural language: MEG evidence for an early contribution of left posterior temporal cortex

2018 ◽  
Author(s):  
Graham Flick ◽  
Liina Pylkkänena
Keyword(s):  
Natural Language ◽  
Language Processing ◽  
Sentence Processing ◽  
Temporal Dynamics ◽  
Temporal Cortex ◽  
Activity Increase ◽  
Semantic Composition ◽  
Left Posterior ◽  
Spatio Temporal ◽  
Sparse Set

ABSTRACTSyntax is the engine that allows us to create an infinitude of linguistic expressions, and the construction of syntactic structures, such as noun phrases and verb phrases, is considered a fundamental component of language processing. Nevertheless, insights concerning the neurobiological basis of syntax have remained elusive, in part because it is difficult to isolate syntax from semantic composition. Consequently, many studies of syntax have relied on meaningless artificial stimuli, such as jabberwocky expressions or artificial grammars. However, while pure manipulations of syntax are challenging to design, natural language grammars do have a sparse set of constructions presenting this possibility. Here we examined one such case, English post-nominal adjectives (mountain TALL enough for a strenuous hike), which were contrasted with semantically parallel but structurally simpler noun-adjective sequences in an MEG experiment. We observed a sharp activity increase in the left posterior temporal lobe (PTL) when syntactic composition was more straightforward, approximately 200 ms after adjective onset. The semantic fit between the noun and adjective was also varied, but this affected anterior temporal cortex, consistent with prior work. These findings offer a unique demonstration of the relevance of posterior temporal cortex for syntactic processing in natural language. We also present connectivity evidence that the syntax-related PTL responses were relayed to ipsilateral inferior frontal and anterior temporal regions. The combined results draw an initial picture of the rapid spatio-temporal dynamics of the syntactic and semantic composition network in sentence processing.

scholarly journals Fast temporal dynamics and causal relevance of face processing in the human temporal cortex

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jessica Schrouff ◽  
Omri Raccah ◽  
Sori Baek ◽  
Vinitha Rangarajan ◽  
Sina Salehi ◽  
...  
Keyword(s):  
Face Processing ◽  
Temporal Dynamics ◽  
Temporal Cortex ◽  
Causal Relevance

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.

Tracking the Spatiotemporal Neural Dynamics of Real-world Object Size and Animacy in the Human Brain

2018 ◽  
Vol 30 (11) ◽  
pp. 1559-1576 ◽  
Author(s):  
Seyed-Mahdi Khaligh-Razavi ◽  
Radoslaw Martin Cichy ◽  
Dimitrios Pantazis ◽  
Aude Oliva
Keyword(s):  
Human Brain ◽  
Real World ◽  
Temporal Dynamics ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Neural Dynamics ◽  
Control Analysis ◽  
Object Size ◽  
Parahippocampal Cortex ◽  
Early Visual Cortex

Animacy and real-world size are properties that describe any object and thus bring basic order into our perception of the visual world. Here, we investigated how the human brain processes real-world size and animacy. For this, we applied representational similarity to fMRI and MEG data to yield a view of brain activity with high spatial and temporal resolutions, respectively. Analysis of fMRI data revealed that a distributed and partly overlapping set of cortical regions extending from occipital to ventral and medial temporal cortex represented animacy and real-world size. Within this set, parahippocampal cortex stood out as the region representing animacy and size stronger than most other regions. Further analysis of the detailed representational format revealed differences among regions involved in processing animacy. Analysis of MEG data revealed overlapping temporal dynamics of animacy and real-world size processing starting at around 150 msec and provided the first neuromagnetic signature of real-world object size processing. Finally, to investigate the neural dynamics of size and animacy processing simultaneously in space and time, we combined MEG and fMRI with a novel extension of MEG–fMRI fusion by representational similarity. This analysis revealed partly overlapping and distributed spatiotemporal dynamics, with parahippocampal cortex singled out as a region that represented size and animacy persistently when other regions did not. Furthermore, the analysis highlighted the role of early visual cortex in representing real-world size. A control analysis revealed that the neural dynamics of processing animacy and size were distinct from the neural dynamics of processing low-level visual features. Together, our results provide a detailed spatiotemporal view of animacy and size processing in the human brain.

Thalamo-cortical spatio-temporal dynamics and its alterations in human brain pathology

NeuroImage ◽  
2000 ◽  
Vol 11 (5) ◽  
pp. S168 ◽  
Author(s):  
U. Ribary ◽  
D. Jeanmonod ◽  
E. Kronberg ◽  
J. Schulman ◽  
K. Suavé ◽  
...  
Keyword(s):  
Human Brain ◽  
Temporal Dynamics ◽  
Brain Pathology ◽  
Spatio Temporal
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