scholarly journals Estimation of gender-specific connectional brain templates using joint multi-view cortical morphological network integration

Author(s):  
Nada Chaari ◽  
Hatice Camgöz Akdağ ◽  
Islem Rekik

Abstract The estimation of a connectional brain template (CBT) integrating a population of brain networks while capturing shared and differential connectional patterns across individuals remains unexplored in gender fingerprinting. This paper presents the first study to estimate gender-specific CBTs using multi-view cortical morphological networks (CMNs) estimated from conventional T1-weighted magnetic resonance imaging (MRI). Specifically, each CMN view is derived from a specific cortical attribute (e.g. thickness), encoded in a network quantifying the dissimilarity in morphology between pairs of cortical brain regions. To this aim, we propose Multi-View Clustering and Fusion Network (MVCF-Net), a novel multi-view network fusion method, which can jointly identify consistent and differential clusters of multi-view datasets in order to capture simultaneously similar and distinct connectional traits of samples. Our MVCF-Net method estimates a representative and well-centered CBTs for male and female populations, independently, to eventually identify their fingerprinting regions of interest (ROIs) in four main steps. First, we perform multi-view network clustering model based on manifold optimization which groups CMNs into shared and differential clusters while preserving their alignment across views. Second, for each view, we linearly fuse CMNs belonging to each cluster, producing local CBTs. Third, for each cluster, we non-linearly integrate the local CBTs across views, producing a cluster-specific CBT. Finally, by linearly fusing the cluster-specific centers we estimate a final CBT of the input population. MVCF-Net produced the most centered and representative CBTs for male and female populations and identified the most discriminative ROIs marking gender differences. The most two gender-discriminative ROIs involved the lateral occipital cortex and pars opercularis in the left hemisphere and the middle temporal gyrus and lingual gyrus in the right hemisphere.

2020 ◽  
Author(s):  
Charalabos Papageorgiou ◽  
Anastasios E. Giannopoulos ◽  
Athanasios S. Fokas ◽  
Paul M. Thompson ◽  
Nikolaos C. Kapsalis ◽  
...  

ABSTRACTHumans are equipped with the so-called Mental Time Travel (MTT) ability, which allows them to consciously construct and elaborate past or future scenes. The mechanisms underlying MTT remain elusive. This study focused on the late positive potential (LPP) and alpha oscillations, considering that LPP covaries with the temporal continuity whereas the alpha oscillations index the temporal organization of perception. To that end, subjects were asked to focus on performing two mental functions engaging working memory, which involved mental self-projection into either the present-past (PP) border or the present-future (PF) border. To evaluate underlying mechanisms, the evoked frontal late positive potentials (LPP) as well as their cortical sources were analyzed via the standardized low-resolution brain electromagnetic tomography (sLORETA) technique. The LPP amplitudes - in the left lateral prefrontal areas that were elicited during PF tasks - were significantly higher than those associated with PP, whereas opposite patterns were observed in the central and right prefrontal areas. Crucially, the LPP activations of both the PP and PF self-projections overlapped with the brain’s default mode network and related interacting areas. Finally, we found enhanced alpha-related activation with respect to PP in comparison to PF, predominantly over the right hemisphere central brain regions (specifically, the precentral gyrus). These findings confirm that the two types of self-projection, as reflected by the frontally-distributed LPP, share common cortical resources that recruit different brain regions in a balanced way. This balanced distribution of brain activation might signify that biological time tends to behave in a homeostatic way.


2017 ◽  
Vol 4 (7) ◽  
pp. 170172 ◽  
Author(s):  
Conor M. Steckler ◽  
J. Kiley Hamlin ◽  
Michael B. Miller ◽  
Danielle King ◽  
Alan Kingstone

Owing to the hemispheric isolation resulting from a severed corpus callosum, research on split-brain patients can help elucidate the brain regions necessary and sufficient for moral judgement. Notably, typically developing adults heavily weight the intentions underlying others' moral actions, placing greater importance on valenced intentions versus outcomes when assigning praise and blame. Prioritization of intent in moral judgements may depend on neural activity in the right hemisphere's temporoparietal junction, an area implicated in reasoning about mental states. To date, split-brain research has found that the right hemisphere is necessary for intent-based moral judgement. When testing the left hemisphere using linguistically based moral vignettes, split-brain patients evaluate actions based on outcomes, not intentions. Because the right hemisphere has limited language ability relative to the left, and morality paradigms to date have involved significant linguistic demands, it is currently unknown whether the right hemisphere alone generates intent-based judgements. Here we use nonlinguistic morality plays with split-brain patient J.W. to examine the moral judgements of the disconnected right hemisphere, demonstrating a clear focus on intent. This finding indicates that the right hemisphere is not only necessary but also sufficient for intent-based moral judgement, advancing research into the neural systems supporting the moral sense.


Author(s):  
Angela D. Friederici ◽  
Noam Chomsky

An adequate description of the neural basis of language processing must consider the entire network both with respect to its structural white matter connections and the functional connectivities between the different brain regions as the information has to be sent between different language-related regions distributed across the temporal and frontal cortex. This chapter discusses the white matter fiber bundles that connect the language-relevant regions. The chapter is broken into three sections. In the first, we look at the white matter fiber tracts connecting the language-relevant regions in the frontal and temporal cortices; in the second, the ventral and dorsal pathways in the right hemisphere that connect temporal and frontal regions; and finally in the third, the two syntax-relevant and (at least) one semantic-relevant neuroanatomically-defined networks that sentence processing is based on. From this discussion, it becomes clear that online language processing requires information transfer via the long-range white matter fiber pathways that connect the language-relevant brain regions within each hemisphere and between hemispheres.


2019 ◽  
Vol 9 (12) ◽  
pp. 363 ◽  
Author(s):  
Fares Al-Shargie ◽  
Usman Tariq ◽  
Omnia Hassanin ◽  
Hasan Mir ◽  
Fabio Babiloni ◽  
...  

In this paper, we present a method to quantify the coupling between brain regions under vigilance and enhanced mental states by utilizing partial directed coherence (PDC) and graph theory analysis (GTA). The vigilance state is induced using a modified version of stroop color-word task (SCWT) while the enhancement state is based on audio stimulation with a pure tone of 250 Hz. The audio stimulation was presented to the right and left ears simultaneously for one-hour while participants perform the SCWT. The quantification of mental states was performed by means of statistical analysis of indexes based on GTA, behavioral responses of time-on-task (TOT), and Brunel Mood Scale (BRMUS). The results show that PDC is very sensitive to vigilance decrement and shows that the brain connectivity network is significantly reduced with increasing TOT, p < 0.05. Meanwhile, during the enhanced state, the connectivity network maintains high connectivity as time passes and shows significant improvements compared to vigilance state. The audio stimulation enhances the connectivity network over the frontal and parietal regions and the right hemisphere. The increase in the connectivity network correlates with individual differences in the magnitude of the vigilance enhancement assessed by response time to stimuli. Our results provide evidence for enhancement of cognitive processing efficiency with audio stimulation. The BRMUS was used to evaluate the emotional states of vigilance task before and after using the audio stimulation. BRMUS factors, such as fatigue, depression, and anger, significantly decrease in the enhancement group compared to vigilance group. On the other hand, happy and calmness factors increased with audio stimulation, p < 0.05.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mi Li ◽  
Hongpei Xu ◽  
Shengfu Lu

Background. In the past, studies on the lateralization of the left and right hemispheres of the brain suggested that depression is dominated by the right hemisphere of the brain, but the neural basis of this theory remains unclear. Method. Functional magnetic resonance imaging of the brain was performed in 22 depressive patients and 15 healthy controls. The differences in the mean values of the regional homogeneity (ReHo) of two groups were compared, and the low-frequency amplitudes of these differential brain regions were compared. Results. The results show that compared with healthy subjects, depressive patients had increased ReHo values in the right superior temporal gyrus, right middle temporal gyrus, left inferior temporal gyrus, left middle temporal gyrus, right middle frontal gyrus, triangular part of the right inferior frontal gyrus, orbital part of the right inferior frontal gyrus, right superior occipital gyrus, right middle occipital gyrus, bilateral anterior cingulate, and paracingulate gyri; reduced ReHo values were seen in the right fusiform gyrus, left middle occipital gyrus, left lingual gyrus, and left inferior parietal except in the supramarginal and angular gyri. Conclusions. The results show that regional homogeneity mainly occurs in the right brain, and the overall performance of the brain is such that right hemisphere synchronization is enhanced while left hemisphere synchronization is weakened. ReHo abnormalities in the resting state can predict abnormalities in individual neurological activities that reflect changes in the structure and function of the brain; abnormalities shown with this indicator are the neuronal basis for the phenomenon that the right hemisphere of the brain has a dominant effect on depression.


Author(s):  
Takahiro Yamanoi ◽  
◽  
Yoshinori Tanaka ◽  
Mika Otsuki ◽  
Shin-ichi Ohnishi ◽  
...  

The authors measure electroencephalograms (EEGs) from a subject looking at line drawings of body parts and recalling their names silently. The equivalent current dipole source localization (ECDL) method is applied to the event related potentials (ERPs): summed EEGs. As the dominant language area of the subject is considered to be in the right hemisphere in the previous research study, ECDs are localized to the right middle temporal gyrus: the angular gyrus. Then ECDs are localized to the right fusiform gyrus, the right middle temporal pole (TEP), and the right inferior temporal white matter (TWM). ECDs are located in the ventral pathway. The areas are related to the integrated process of visual recognition of pictures and the recalling of words. Some of these areas are also related to image recognition and word generation.


2016 ◽  
Vol 87 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Raúl Sobrero ◽  
Pedro Fernández-Aburto ◽  
Álvaro Ly-Prieto ◽  
Scarlett E. Delgado ◽  
Jorge Mpodozis ◽  
...  

Navigational and social challenges due to habitat conditions and sociality are known to influence dentate gyrus (DG) morphology, yet the relative importance of these factors remains unclear. Thus, we studied three natural populations of O. lunatus (Los Molles) and Octodon degus (El Salitre and Rinconada), two caviomorph species that differ in the extent of sociality and with contrasting vegetation cover of habitat used. The brains and DG of male and female breeding degus with simultaneous information on their physical and social environments were examined. The extent of sociality was quantified from total group size and range area overlap. O. degus at El Salitre was more social than at Rinconada and than O. lunatus from Los Molles. The use of transects to quantify cover of vegetation (and other physical objects in the habitat) and measures of the spatial behavior of animals indicated animal navigation based on unique cues or global landmarks is more cognitively challenging to O. lunatus. During lactation, female O. lunatus had larger brains than males. Relative DG volume was similar across sexes and populations. The right hemisphere of male and female O. lunatus had more cells than the left hemisphere, with DG directional asymmetry not found in O. degus. Degu population differences in brain size and DG cell number seemed more responsive to differences in habitat than to differences in sociality. Yet, large-sized O. degus (but not O. lunatus) that ranged over larger areas and were members of larger social groups had more DG cells per hemisphere. Thus, within-population variation in DG cell number by hemisphere was consistent with a joint influence of habitat and sociality in O. degus at El Salitre.


2021 ◽  
Vol 15 ◽  
Author(s):  
Yan He ◽  
Yinying Hu ◽  
Yaxi Yang ◽  
Defeng Li ◽  
Yi Hu

Recent neuroimaging research has suggested that unequal cognitive efforts exist between interpreting from language 1 (L1) to language 2 (L2) compared with interpreting from L2 to L1. However, the neural substrates that underlie this directionality effect are not yet well understood. Whether directionality is modulated by interpreting expertise also remains unknown. In this study, we recruited two groups of Mandarin (L1)/English (L2) bilingual speakers with varying levels of interpreting expertise and asked them to perform interpreting and reading tasks. Functional near-infrared spectroscopy (fNIRS) was used to collect cortical brain data for participants during each task, using 68 channels that covered the prefrontal cortex and the bilateral perisylvian regions. The interpreting-related neuroimaging data was normalized by using both L1 and L2 reading tasks, to control the function of reading and vocalization respectively. Our findings revealed the directionality effect in both groups, with forward interpreting (from L1 to L2) produced more pronounced brain activity, when normalized for reading. We also found that directionality was modulated by interpreting expertise in both normalizations. For the group with relatively high expertise, the activated brain regions included the right Broca’s area and the left premotor and supplementary motor cortex; whereas for the group with relatively low expertise, the activated brain areas covered the superior temporal gyrus, the dorsolateral prefrontal cortex (DLPFC), the Broca’s area, and visual area 3 in the right hemisphere. These findings indicated that interpreting expertise modulated brain activation, possibly because of more developed cognitive skills associated with executive functions in experienced interpreters.


Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1549
Author(s):  
Amedeo D’Angiulli ◽  
Darren Kenney ◽  
Dao Anh Thu Pham ◽  
Etienne Lefebvre ◽  
Justin Bellavance ◽  
...  

We explored whether two visual mental imagery experiences may be differentiated by electroencephalographic (EEG) and performance interactions with concurrent orienting external attention (OEA) to stimulus location and subsequent visuospatial detection. We measured within-subject (N = 10) event-related potential (ERP) changes during out-of-body imagery (OBI)—vivid imagery of a vertical line outside of the head/body—and within-body imagery (WBI)—vivid imagery of the line within one’s own head. Furthermore, we measured ERP changes and line offset Vernier acuity (hyperacuity) performance concurrent with those imagery, compared to baseline detection without imagery. Relative to OEA baseline, OBI yielded larger N200 and P300, whereas WBI yielded larger P50, P100, N400, and P800. Additionally, hyperacuity dropped significantly when concurrent with both imagery types. Partial least squares analysis combined behavioural performance, ERPs, and/or event-related EEG band power (ERBP). For both imagery types, hyperacuity reduction correlated with opposite frontal and occipital ERP amplitude and polarity changes. Furthermore, ERP modulation and ERBP synchronizations for all EEG frequencies correlated inversely with hyperacuity. Dipole Source Localization Analysis revealed unique generators in the left middle temporal gyrus (WBI) and in the right frontal middle gyrus (OBI), whereas the common generators were in the left precuneus and middle occipital cortex (cuneus). Imagery experiences, we conclude, can be identified by symmetric and asymmetric combined neurophysiological-behavioural patterns in interactions with the width of attentional focus.


2020 ◽  
Vol 1 (3) ◽  
pp. 339-364
Author(s):  
David I. Saltzman ◽  
Emily B. Myers

The extent that articulatory information embedded in incoming speech contributes to the formation of new perceptual categories for speech sounds has been a matter of discourse for decades. It has been theorized that the acquisition of new speech sound categories requires a network of sensory and speech motor cortical areas (the “dorsal stream”) to successfully integrate auditory and articulatory information. However, it is possible that these brain regions are not sensitive specifically to articulatory information, but instead are sensitive to the abstract phonological categories being learned. We tested this hypothesis by training participants over the course of several days on an articulable non-native speech contrast and acoustically matched inarticulable nonspeech analogues. After reaching comparable levels of proficiency with the two sets of stimuli, activation was measured in fMRI as participants passively listened to both sound types. Decoding of category membership for the articulable speech contrast alone revealed a series of left and right hemisphere regions outside of the dorsal stream that have previously been implicated in the emergence of non-native speech sound categories, while no regions could successfully decode the inarticulable nonspeech contrast. Although activation patterns in the left inferior frontal gyrus, the middle temporal gyrus, and the supplementary motor area provided better information for decoding articulable (speech) sounds compared to the inarticulable (sine wave) sounds, the finding that dorsal stream regions do not emerge as good decoders of the articulable contrast alone suggests that other factors, including the strength and structure of the emerging speech categories are more likely drivers of dorsal stream activation for novel sound learning.


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