scholarly journals Anosognosia for Hemiplegia as a tripartite disconnection syndrome

2019 ◽  
Author(s):  
V. Pacella ◽  
C. Foulon ◽  
P.M. Jenkinson ◽  
M. Scandola ◽  
S. Bertagnoli ◽  
...  
Keyword(s):  
Neural Networks ◽  
Limbic System ◽  
Right Hemisphere ◽  
Attention Network ◽  
Disconnection Syndrome ◽  
Motor Awareness ◽  
Human Motor ◽  
Joint Contribution ◽  
Loop 2 ◽  
Anosognosia For Hemiplegia

AbstractThe rare syndrome of Anosognosia for Hemiplegia (AHP) can provide unique insights into the neurocognitive processes of motor awareness. Yet, prior studies have only explored predominately discreet lesions. Using advanced structural neuroimaging methods in 174 patients with a right-hemisphere stroke, we were able to identify three neural networks that contribute to AHP, when disconnected: the (1) premotor loop (2) limbic system, and (3) ventral attention network. Our results suggest that human motor awareness is contingent on the joint contribution of these three systems.

scholarly journals Anosognosia for hemiplegia as a tripartite disconnection syndrome

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Valentina Pacella ◽  
Chris Foulon ◽  
Paul M Jenkinson ◽  
Michele Scandola ◽  
Sara Bertagnoli ◽  
...  
Keyword(s):  
Limbic System ◽  
Right Hemisphere ◽  
Neural Systems ◽  
Structural Neuroimaging ◽  
Disconnection Syndrome ◽  
Attentional Network ◽  
Motor Awareness ◽  
Human Motor ◽  
Joint Contribution ◽  
Anosognosia For Hemiplegia

The syndrome of Anosognosia for Hemiplegia (AHP) can provide unique insights into the neurocognitive processes of motor awareness. Yet, prior studies have only explored predominately discreet lesions. Using advanced structural neuroimaging methods in 174 patients with a right-hemisphere stroke, we were able to identify three neural systems that contribute to AHP, when disconnected or directly damaged: the (i) premotor loop (ii) limbic system, and (iii) ventral attentional network. Our results suggest that human motor awareness is contingent on the joint contribution of these three systems.

Anosognosia for hemiplegia as a global deficit in motor awareness: Evidence from the non-paralysed limb

2010 ◽  
Vol 48 (12) ◽  
pp. 3443-3450 ◽  
Author(s):  
Catherine Preston ◽  
Paul M. Jenkinson ◽  
Roger Newport
Keyword(s):  
Motor Awareness ◽  
Anosognosia For Hemiplegia

scholarly journals What executive function network is that? An image-based meta-analysis of network labels

2020 ◽  
Author(s):  
Suzanne T. Witt ◽  
Helene van Ettinger-Veenstra ◽  
Taylor Salo ◽  
Michael C. Riedel ◽  
Angela R. Laird
Keyword(s):  
Neural Networks ◽  
Executive Function ◽  
Meta Analysis ◽  
Control Network ◽  
Attention Network ◽  
Frontoparietal Network ◽  
Current State ◽  
The Neural Networks ◽  
Task Positive Network ◽  
Spatial Topography

AbstractThe current state of label conventions used to describe brain networks related to executive functions is highly inconsistent, leading to confusion among researchers regarding network labels. Visually similar networks are referred to by different labels, yet these same labels are used to distinguish networks within studies. We performed a literature review of fMRI studies and identified nine frequently-used labels that are used to describe topographically or functionally similar neural networks: central executive network (CEN), cognitive control network (CCN), dorsal attention network (DAN), executive control network (ECN), executive network (EN), frontoparietal network (FPN), working memory network (WMN), task positive network (TPN), and ventral attention network (VAN). Our aim was to meta-analytically determine consistency of network topography within and across these labels. We hypothesized finding considerable overlap in the spatial topography among the neural networks associated with these labels. An image-based meta-analysis was performed on 166 individual statistical maps (SPMs) received from authors of 72 papers listed on PubMed. Our results indicated that there was very little consistency in the SPMs labeled with a given network name. We identified four clusters of SPMs representing four spatially distinct executive function networks. We provide recommendations regarding label nomenclature and propose that authors looking to assign labels to executive function networks adopt this template set for labeling networks.

scholarly journals Awareness is in the Eye of the Observer: Preserved Third-Person Awareness of Deficit in Anosognosia for Hemiplegia

2021 ◽  
Author(s):  
Sahba Besharati ◽  
Paul Jenkinson ◽  
Michael Kopelman ◽  
Mark Solms ◽  
Valentina Moro ◽  
...  
Keyword(s):  
Social Cognition ◽  
Perspective Taking ◽  
Right Hemisphere ◽  
First Person ◽  
Self Awareness ◽  
Person Perspective ◽  
Right Hemisphere Damage ◽  
Third Person ◽  
Third Person Perspective ◽  
Anosognosia For Hemiplegia

In recent decades, the research traditions of (first-person) embodied cognition and of (third-person) social cognition have approached the study of self-awareness with relative independence. However, neurological disorders of self-awareness offer a unifying perspective to empirically investigate the contribution of embodiment and social cognition to self-awareness. This study focused on a neuropsychological disorder of bodily self-awareness following right-hemisphere damage, namely anosognosia for hemiplegia (AHP). A previous neuropsychological study has shown AHP patients, relative to neurological controls, to have a specific deficit in third-person, allocentric inferences in a story-based, mentalisation task. However, no study has tested directly whether verbal awareness of motor deficits is influenced by either perspective-taking or centrism, and if these deficits in social cognition are correlated with damage to anatomical areas previously linked to mentalising, including the supramarginal and superior temporal gyri and related limbic white matter connections. Accordingly, two novel experiments were conducted with right-hemisphere stroke patients with (n = 17) and without AHP (n = 17) that targeted either their own (egocentric, experiment 1) or another stooge patient’s (experiment 2) motor abilities from a first-or-third person (allocentric in Experiment 2) perspective. In both experiments, neurological controls showed no significant difference between perspectives, suggesting that perspective-taking deficits are not a general consequence of right-hemisphere damage. More specifically, experiment 1 found AHP patients were more aware of their own motor paralysis when asked from a third compared to a first-person perspective, using both group level and individual level analysis. In experiment 2, AHP patients were less accurate than controls in making allocentric, third-person perspective judgements about the stooge patient, but with only a trend towards significance and with no within-group, difference between perspectives. Deficits in egocentric and allocentric third-person perspective taking were associated with lesions in the middle frontal gyrus, superior temporal and supramarginal gyri, with white matter disconnections more predominate in deficits in allocentricity. This study confirms previous clinical and empirical investigations on the selectivity of first-person motor awareness deficits in anosognosia for hemiplegia and experimentally demonstrates for the first time that verbal egocentric 3PP-taking can positively influence 1PP body awareness.

The Neural Underpinings of Simultanagnosia: Disconnecting the Visuospatial Attention Network

2012 ◽  
Vol 24 (3) ◽  
pp. 718-735 ◽  
Author(s):  
Magdalena Chechlacz ◽  
Pia Rotshtein ◽  
Peter C. Hansen ◽  
Jane M. Riddoch ◽  
Shoumitro Deb ◽  
...  
Keyword(s):  
Gray Matter ◽  
Visual Processing ◽  
Right Hemisphere ◽  
Functional Organization ◽  
Visuospatial Attention ◽  
Lesion Volume ◽  
Voxel Based Morphometry ◽  
Attention Network ◽  
Visuospatial Deficits ◽  
Laterality Index

Because of our limited processing capacity, different elements of the visual scene compete for the allocation of processing resources. One of the most striking deficits in visual selection is simultanagnosia, a rare neuropsychological condition characterized by impaired spatial awareness of more than one object at time. To decompose the neuroanatomical substrates of the syndrome and to gain insights into the structural and functional organization of visuospatial attention, we performed a systematic evaluation of lesion patterns in a group of simultanagnosic patients compared with patients with either (i) unilateral visuospatial deficits (neglect and/or extinction) or (ii) bilateral posterior lesions without visuospatial deficits, using overlap/subtraction analyses, estimation of lesion volume, and a lesion laterality index. We next used voxel-based morphometry to assess the link between different visuospatial deficits and gray matter and white matter (WM) damage. Lesion overlap/subtraction analyses, lesion laterality index, and voxel-based morphometry measures converged to indicate that bilateral parieto-occipital WM disconnections are both distinctive and necessary to create symptoms associated with simultanagnosia. We also found that bilateral gray matter damage within the middle frontal area (BA 46), cuneus, calacarine, and parieto-occipital fissure as well as right hemisphere parietal lesions within intraparietal and postcentral gyri were associated with simultanagnosia. Further analysis of the WM based on tractography revealed associations with bilateral damage to major pathways within the visuospatial attention network, including the superior longitudinal fasciculus, the inferior fronto-occipital fasciculus, and the inferior longitudinal fasciculus. We conclude that damage to the parieto-occipital regions and the intraparietal sulcus, together, with bilateral WM disconnections within the visuosptial attention network, contribute to poor visual processing of multiple objects and the loss of processing speed characteristic of simultanagnosia.

scholarly journals An End-to-End Visual-Audio Attention Network for Emotion Recognition in User-Generated Videos

2020 ◽  
Vol 34 (01) ◽  
pp. 303-311 ◽  
Author(s):  
Sicheng Zhao ◽  
Yunsheng Ma ◽  
Yang Gu ◽  
Jufeng Yang ◽  
Tengfei Xing ◽  
...  
Keyword(s):  
Neural Networks ◽  
Emotion Recognition ◽  
State Of The Art ◽  
Source Code ◽  
Cross Entropy ◽  
Attention Network ◽  
Audio Features ◽  
End To End ◽  
3D Cnn ◽  
And Training

Emotion recognition in user-generated videos plays an important role in human-centered computing. Existing methods mainly employ traditional two-stage shallow pipeline, i.e. extracting visual and/or audio features and training classifiers. In this paper, we propose to recognize video emotions in an end-to-end manner based on convolutional neural networks (CNNs). Specifically, we develop a deep Visual-Audio Attention Network (VAANet), a novel architecture that integrates spatial, channel-wise, and temporal attentions into a visual 3D CNN and temporal attentions into an audio 2D CNN. Further, we design a special classification loss, i.e. polarity-consistent cross-entropy loss, based on the polarity-emotion hierarchy constraint to guide the attention generation. Extensive experiments conducted on the challenging VideoEmotion-8 and Ekman-6 datasets demonstrate that the proposed VAANet outperforms the state-of-the-art approaches for video emotion recognition. Our source code is released at: https://github.com/maysonma/VAANet.

scholarly journals Artificial Intelligence to Analyze the Cortical Thickness Through Age

2021 ◽  
Vol 4 ◽  
Author(s):  
Sergio Ledesma ◽  
Mario-Alberto Ibarra-Manzano ◽  
Dora-Luz Almanza-Ojeda ◽  
Pascal Fallavollita ◽  
Jason Steffener
Keyword(s):  
Artificial Intelligence ◽  
Neural Networks ◽  
Artificial Neural Networks ◽  
Left Hemisphere ◽  
Cortical Thickness ◽  
Right Hemisphere ◽  
Unseen Data ◽  
Artificial Neural ◽  
The Right ◽  
The Brain

In this study, Artificial Intelligence was used to analyze a dataset containing the cortical thickness from 1,100 healthy individuals. This dataset had the cortical thickness from 31 regions in the left hemisphere of the brain as well as from 31 regions in the right hemisphere. Then, 62 artificial neural networks were trained and validated to estimate the number of neurons in the hidden layer. These neural networks were used to create a model for the cortical thickness through age for each region in the brain. Using the artificial neural networks and kernels with seven points, numerical differentiation was used to compute the derivative of the cortical thickness with respect to age. The derivative was computed to estimate the cortical thickness speed. Finally, color bands were created for each region in the brain to identify a positive derivative, that is, a part of life with an increase in cortical thickness. Likewise, the color bands were used to identify a negative derivative, that is, a lifetime period with a cortical thickness reduction. Regions of the brain with similar derivatives were organized and displayed in clusters. Computer simulations showed that some regions exhibit abrupt changes in cortical thickness at specific periods of life. The simulations also illustrated that some regions in the left hemisphere do not follow the pattern of the same region in the right hemisphere. Finally, it was concluded that each region in the brain must be dynamically modeled. One advantage of using artificial neural networks is that they can learn and model non-linear and complex relationships. Also, artificial neural networks are immune to noise in the samples and can handle unseen data. That is, the models based on artificial neural networks can predict the behavior of samples that were not used for training. Furthermore, several studies have shown that artificial neural networks are capable of deriving information from imprecise data. Because of these advantages, the results obtained in this study by the artificial neural networks provide valuable information to analyze and model the cortical thickness.

scholarly journals Author response: Anosognosia for hemiplegia as a tripartite disconnection syndrome

2019 ◽  
Author(s):  
Valentina Pacella ◽  
Chris Foulon ◽  
Paul M Jenkinson ◽  
Michele Scandola ◽  
Sara Bertagnoli ◽  
...  
Keyword(s):  
Author Response ◽  
Disconnection Syndrome ◽  
Anosognosia For Hemiplegia

scholarly journals Motor versus body awareness: Voxel-based lesion analysis in anosognosia for hemiplegia and somatoparaphrenia following right hemisphere stroke

Cortex ◽  
2016 ◽  
Vol 83 ◽  
pp. 62-77 ◽  
Author(s):  
Valentina Moro ◽  
Simone Pernigo ◽  
Manos Tsakiris ◽  
Renato Avesani ◽  
Nicola M.J. Edelstyn ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Body Awareness ◽  
Lesion Analysis ◽  
Anosognosia For Hemiplegia ◽  
Right Hemisphere Stroke
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