scholarly journals Structural and functional brain asymmetries in the early phases of life: a scoping review

2021 ◽  
Author(s):  
Patrizia Bisiacchi ◽  
Elisa Cainelli
Keyword(s):  
Scoping Review ◽  
Right Hemisphere ◽  
Final Analysis ◽  
Brain Structures ◽  
Large Variability ◽  
Speech Stimuli ◽  
Morphological Asymmetry ◽  
Cerebral Asymmetries ◽  
The Right ◽  
And Function

AbstractAsymmetry characterizes the brain in both structure and function. Anatomical asymmetries explain only a fraction of functional variability in lateralization, with structural and functional asymmetries developing at different periods of life and in different ways. In this work, we perform a scoping review of the cerebral asymmetries in the first brain development phases. We included all English-written studies providing direct evidence of hemispheric asymmetries in full-term neonates, foetuses, and premature infants, both at term post-conception and before. The final analysis included 57 studies. The reviewed literature shows large variability in the used techniques and methodological procedures. Most structural studies investigated the temporal lobe, showing a temporal planum more pronounced on the left than on the right (although not all data agree), a morphological asymmetry already present from the 29th week of gestation. Other brain structures have been poorly investigated, and the results are even more discordant. Unlike data on structural asymmetries, functional data agree with each other, identifying a leftward dominance for speech stimuli and an overall dominance of the right hemisphere in all other functional conditions. This generalized dominance of the right hemisphere for all conditions (except linguistic stimuli) is in line with theories stating that the right hemisphere develops earlier and that its development is less subject to external influences because it sustains functions necessary to survive.

scholarly journals Fundamental Nature of Human Infant's Brain Asymmetry

1977 ◽  
Vol 4 (3) ◽  
pp. 203-207 ◽  
Author(s):  
Juhn A. Wada ◽  
Alan E. Davis
Keyword(s):  
Visual Information ◽  
Right Hemisphere ◽  
Functional Implication ◽  
Speech Stimuli ◽  
Morphological Asymmetry ◽  
Developmental Factors ◽  
Verbal Content ◽  
The Right ◽  
Temporal Coherency

SUMMARY:Morphological speech zone asymmetry in man cannot be due to environmental or developmental factors after birth. The functional implication of such a finding is not yet clear. Morphological asymmetry of the human brain is paralleled by electrophysiological evidence of cerebral hemispheric asymmetries. The results of our analysis of 50 infants suggest that clear occipital-temporal coherency asymmetry similar, but not identical to the adult pattern, also exists at or near birth. These asymmetries are generated by stimuli with no verbal content and in infants who presumably have no or an undeveloped capability for language. It is suggested that language is only a part of much more fundamental asymmetries which include the processing of auditory and visual information. Our results, and those of others, are consistent with the assumption that the left hemisphere is more able to relate stimuli to past experience, either short or long-term, while the right hemisphere is more able to process stimuli which are not easily identifiable or referable. These capabilities would not be based on language, and hence would be expected to develop independently and possibly before speech. The demonstration that reversing electrophysiological asymmetries can be generated with non-speech stimuli in the visual and auditory modalities, and in neonates, supports such an assumption.

scholarly journals Asymmetry in the content of brain monoamines of BALB/c mice reared in social isolation conditions

2012 ◽  
Vol 10 (4) ◽  
pp. 42-48 ◽  
Author(s):  
Inessa Vladimirovna Karpova ◽  
Vladimir Vladimirovich Mikheyev ◽  
Yevgeniy Rudolfovich Bychkov ◽  
Andrey Andreyevich Lebedev ◽  
Petr Dmitriyevich Shabanov
Keyword(s):  
Social Isolation ◽  
Elevated Level ◽  
Right Hemisphere ◽  
Brain Structures ◽  
Brain Monoamines ◽  
Left Hippocampus ◽  
The Right ◽  
High Level ◽  
The Brain

The effects of long-term social isolation on the content and metabolism of dopamine and serotonin systems were studied in symmetrical brain structures of BALB/c male mice. With HPLC the contents of dopamine (DA), serotonin (5-HT) and their metabolites dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindolacetic acid (5-HIAA) were measured in the cortex, hippocampus and striatum of both the right and the left hemispheres of the brain in mice reared in groups and social isolation. The isolated mice were characterized by reduced level of DA in the left striatum and elevated level of 5-HIAA and ratio 5-HIAA/5-HT in the right striatum. In the hippocampus of isolated mice, the activation of both DA-ergic and 5-HT-ergic systems was observed, that is the high level of DA and DOPAC in the left hippocampus and the elevated level of 5-HT in both hemispheres and of 5-HIAA in the right hippocampus were registered. On the other hand, the reduction of both DA-ergic and 5-HT-ergic systems activity was shown to be in the right hemisphere. The decreased concentration of DOPAC and ratio DOPAC/DA in the right cortex were observed as well. As to 5-HT-ergic system, the reduced level of 5-HT in the both cortex of the hemispheres as well as 5-HIAA in the right hemisphere of isolated mice was determined. The phenomenon of interhemispheric asymmetry was revealed in the hippocampus only, which was characterized by the increased DA-ergic activity in the left hippocampus but not in the striatum and the cortex.

scholarly journals Effective inter-organisational networks for Responsible Research and Innovation and global sustainability: a scoping review

2021 ◽  
Vol 1 ◽  
pp. 144
Author(s):  
Danielle Martine Farrugia ◽  
Silvia Leonor Vilches ◽  
Alexander Gerber
Keyword(s):  
Scoping Review ◽  
Network Theory ◽  
Final Analysis ◽  
Responsible Research And Innovation ◽  
Global Issues ◽  
Research And Innovation ◽  
Development Goals ◽  
Relationship Network ◽  
And Function ◽  
Responsible Research

Background: Achieving the United Nations Sustainable Development Goals (SDGs) is beyond the capacity of any single organisation. The principles of engaging stakeholders suggest that an engaged, multi-sectoral approach, such as described in models of Responsible Research and Innovation (RRI), hold promise to mobilise humanity to solve complex and urgent global issues. Methods: This scoping review explores the characteristics of effective and sustainable inter-organisational networks for fostering RRI in service of the SDGs. The review focuses on strategies to initiate and maintain international communities of practice relevant to the implementation of RRI and/or SDGs. The search began with themes derived from prior network theory, focusing on: (a) the type and function of networks; (b) the aims and vision; and (c) the relationships between networks and network members. In total, 55 articles on inter-organisational network theory were included for the final analysis. Results:  Results are reported under themes of: (1) Effectiveness, Sustainability, and Success; (2) Governance and Management; and (3) Network Relationship. Network structures, forms of management and funding are linked to sustainable networks. Potential threats include power imbalances within networks, and internal and external factors that may affect relationships at network and community levels. Few studies examine diversity or cultural viewpoints. Studies highlight the benefits of networks such as enhancing knowledge sharing among researchers, practitioners, and other stakeholders. Conclusions: The effectiveness of the managerial structure may be observed as outputs of the intention and values of an inter-organisational network. Our review demonstrates that a global inter-organisational network approach is achievable. Such a network would have many benefits, including allowing organisations to be responsive and flexible towards change and innovation.

Sex hormonal modulation of hemispheric asymmetries in the attentional blink

2005 ◽  
Vol 11 (3) ◽  
pp. 263-272 ◽  
Author(s):  
ANTJE HOLLÄNDER ◽  
MARKUS HAUSMANN ◽  
JEFF P. HAMM ◽  
MICHAEL C. CORBALLIS
Keyword(s):  
Visual Field ◽  
Attentional Blink ◽  
Right Hemisphere ◽  
Visual Presentation ◽  
Right Visual Field ◽  
Probe Item ◽  
Cerebral Asymmetries ◽  
Hormonal Modulation ◽  
The Right ◽  
Midluteal Phase

The present study examines differences in functional cerebral asymmetries modulated by gonadal steroid hormones during the menstrual cycle in women. Twenty-one right-handed women with regular menstrual cycles performed a double-stream rapid serial visual presentation (RSVP) task, with one stream in each visual field, during the low steroid menses and the high steroid midluteal phase. They were required to detect a target item, and then a probe item, each of which could appear in either stream. If the probe item appeared 200 ms after the target, detection of the probe was impaired—a phenomenon known as the “attentional blink.” This occurred in both streams in the midluteal phase, but only in the right visual field during menses. Thus low steroid levels appeared to restrict the attentional blink to the left hemisphere, while high levels of estradiol and progesterone in the midluteal phase appeared to reduce functional asymmetries by selectively increasing the attentional blink in the right hemisphere. This effect appears to be mediated by estradiol rather than progesterone, and it is compatible with the assumption of a hormone-related suppression of right hemisphere functions during the midluteal phase. (JINS, 2005,11, 263–272.)

Emotions and the Right Hemisphere: Can New Data Clarify Old Models?

2018 ◽  
Vol 25 (3) ◽  
pp. 258-270 ◽  
Author(s):  
Guido Gainotti
Keyword(s):  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Conscious Experience ◽  
Critical Role ◽  
Brain Structures ◽  
Experimental Investigations ◽  
Cognition And Emotion ◽  
Clinical Observations ◽  
Hemisphere Dominance ◽  
The Right

Models advanced to explain hemispheric asymmetries in representation of emotions will be discussed following their historical progression. First, the clinical observations that have suggested a general dominance of the right hemisphere for all kinds of emotions will be reviewed. Then the experimental investigations that have led to proposal of a different hemispheric specialization for positive versus negative emotions (valence hypothesis) or, alternatively, for approach versus avoidance tendencies (motivational hypothesis) will be surveyed. The discussion of these general models will be followed by a review of recent studies which have documented laterality effects within specific brain structures, known to play a critical role in different components of emotions, namely the amygdata in the computation of emotionally laden stimuli, the ventromedial prefrontal cortex in the integration between cognition and emotion and in the control of impulsive reactions and the anterior insula in the conscious experience of emotion. Results of these recent investigations support and provide an updated integrated version of early models assuming a general right hemisphere dominance for all kinds of emotions.

CNTM-05. Left hemisphere gliomas induce a plastic bi-hemispheric language network further characterized by lobe specific glioma data

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi225-vi225
Author(s):  
Matthew Ramsey ◽  
Shashwat Tripathi ◽  
Mohit Saxena ◽  
Matthew Tate
Keyword(s):  
Left Hemisphere ◽  
Time Course ◽  
Right Hemisphere ◽  
Final Analysis ◽  
Therapeutic Benefit ◽  
Control Group ◽  
Language Activation ◽  
Nuanced Understanding ◽  
The Right ◽  
Language Network

Abstract Primary brain tumors are among the most burdensome diagnoses patients can receive as they often carry with them externally obvious and significant detriments to motor and speech. The stroke model is severely limited by the inherent nature of the insult to the brain: binary, relatively instantaneous and defined by vascular boundaries. We instead have chosen to study glioma-induced neuroplasticity in patients with gliomas as presentation is over a significantly longer time course with a gradient of insult to language activation areas instead of immediate ablation. Chart review was conducted on 545 patients who completed fMRI imaging from 2013–2019 while completing 1+ of the following language tasks: antonyms, reading comprehension, rhyming, word generation and picture naming. A total of 117 patients’ fMRI scans were included in the final analysis which entailed both a cluster-based analysis in FSL and a 34 gyral, mask-based analysis using FEATquery. Right hemisphere gliomas (RHG) were first established as a reliable control group by averaging anatomically significant voxels across all five language tasks (LT) yielding a core conserved network. Left hemisphere gliomas (LHG) were then directly compared to the RHG language tasks. We found LHG induced global reorganization of the conserved language network with little evidence for direct homologous recruitment of functional structures. Instead, a generalized right hemisphere recruitment is observed with 87% of non-zero masks shifting their laterality index to the right hemisphere. Furthermore, in each of the five LT, the LHG activates fewer total suprathreshold voxels in both the mask and cluster based analyses while having a higher peak intensity within the activated clusters. A preliminary analysis of frontal LHG compared to temporal LHG reveals increased contralateral recruitment in the frontal subgroup with more direct homologous recruitment. This nuanced understanding of existing mechanisms for neuroplasticity can aid in our future intentional manipulation for therapeutic benefit.

scholarly journals Is it left or is it right? A classification approach for investigating hemispheric differences in low and high dimensionality

2021 ◽  
Author(s):  
Patrick Friedrich ◽  
Kaustubh R. Patil ◽  
Lisa N. Mochalski ◽  
Xuan Li ◽  
Julia A. Camilleri ◽  
...  
Keyword(s):  
Feature Selection ◽  
Right Hemisphere ◽  
Dimensional Space ◽  
High Dimensional ◽  
Hemispheric Differences ◽  
Dimensional Representation ◽  
Left And Right ◽  
Low Dimensional ◽  
The Right ◽  
And Function

AbstractHemispheric asymmetries, i.e., differences between the two halves of the brain, have extensively been studied with respect to both structure and function. Commonly employed pairwise comparisons between left and right are suitable for finding differences between the hemispheres, but they come with several caveats when assessing multiple asymmetries. What is more, they are not designed for identifying the characterizing features of each hemisphere. Here, we present a novel data-driven framework—based on machine learning-based classification—for identifying the characterizing features that underlie hemispheric differences. Using voxel-based morphometry data from two different samples (n = 226, n = 216), we separated the hemispheres along the midline and used two different pipelines: First, for investigating global differences, we embedded the hemispheres into a two-dimensional space and applied a classifier to assess if the hemispheres are distinguishable in their low-dimensional representation. Second, to investigate which voxels show systematic hemispheric differences, we employed two classification approaches promoting feature selection in high dimensions. The two hemispheres were accurately classifiable in both their low-dimensional (accuracies: dataset 1 = 0.838; dataset 2 = 0.850) and high-dimensional (accuracies: dataset 1 = 0.966; dataset 2 = 0.959) representations. In low dimensions, classification of the right hemisphere showed higher precision (dataset 1 = 0.862; dataset 2 = 0.894) compared to the left hemisphere (dataset 1 = 0.818; dataset 2 = 0.816). A feature selection algorithm in the high-dimensional analysis identified voxels that most contribute to accurate classification. In addition, the map of contributing voxels showed a better overlap with moderate to highly lateralized voxels, whereas conventional t test with threshold-free cluster enhancement best resembled the LQ map at lower thresholds. Both the low- and high-dimensional classifiers were capable of identifying the hemispheres in subsamples of the datasets, such as males, females, right-handed, or non-right-handed participants. Our study indicates that hemisphere classification is capable of identifying the hemisphere in their low- and high-dimensional representation as well as delineating brain asymmetries. The concept of hemisphere classifiability thus allows a change in perspective, from asking what differs between the hemispheres towards focusing on the features needed to identify the left and right hemispheres. Taking this perspective on hemispheric differences may contribute to our understanding of what makes each hemisphere special.

Investigation of the Effect of Mode and Tempo on Emotional Responses to Music Using EEG Power Asymmetry

2013 ◽  
Vol 27 (3) ◽  
pp. 142-148 ◽  
Author(s):  
Konstantinos Trochidis ◽  
Emmanuel Bigand
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Emotional Responses ◽  
Interactive Effects ◽  
Eeg Activity ◽  
Musical Excerpt ◽  
Major Mode ◽  
Musical Modes ◽  
Slow Tempo ◽  
The Right

The combined interactions of mode and tempo on emotional responses to music were investigated using both self-reports and electroencephalogram (EEG) activity. A musical excerpt was performed in three different modes and tempi. Participants rated the emotional content of the resulting nine stimuli and their EEG activity was recorded. Musical modes influence the valence of emotion with major mode being evaluated happier and more serene, than minor and locrian modes. In EEG frontal activity, major mode was associated with an increased alpha activation in the left hemisphere compared to minor and locrian modes, which, in turn, induced increased activation in the right hemisphere. The tempo modulates the arousal value of emotion with faster tempi associated with stronger feeling of happiness and anger and this effect is associated in EEG with an increase of frontal activation in the left hemisphere. By contrast, slow tempo induced decreased frontal activation in the left hemisphere. Some interactive effects were found between mode and tempo: An increase of tempo modulated the emotion differently depending on the mode of the piece.

Right-Hemisphere Specialization for Contour Grouping

2014 ◽  
Vol 61 (5) ◽  
pp. 331-339 ◽  
Author(s):  
Gregor Volberg
Keyword(s):  
Right Hemisphere ◽  
Contour Detection ◽  
Global Processing ◽  
Detection Accuracy ◽  
Frequency Spectra ◽  
Visual Hemifield ◽  
Spatial Frequencies ◽  
A Chain ◽  
The Right ◽  
Hemisphere Specialization

Previous studies often revealed a right-hemisphere specialization for processing the global level of compound visual stimuli. Here we explore whether a similar specialization exists for the detection of intersected contours defined by a chain of local elements. Subjects were presented with arrays of randomly oriented Gabor patches that could contain a global path of collinearly arranged elements in the left or in the right visual hemifield. As expected, the detection accuracy was higher for contours presented to the left visual field/right hemisphere. This difference was absent in two control conditions where the smoothness of the contour was decreased. The results demonstrate that the contour detection, often considered to be driven by lateral coactivation in primary visual cortex, relies on higher-level visual representations that differ between the hemispheres. Furthermore, because contour and non-contour stimuli had the same spatial frequency spectra, the results challenge the view that the right-hemisphere advantage in global processing depends on a specialization for processing low spatial frequencies.

Thinking in Animals, Infants, and the Right Hemisphere

1990 ◽  
Vol 35 (6) ◽  
pp. 544-547
Author(s):  
Randi C. Martin
Keyword(s):  
Right Hemisphere ◽  
The Right
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