Effects of Habitat and Social Complexity on Brain Size, Brain Asymmetry and Dentate Gyrus Morphology in Two Octodontid Rodents

2016 ◽  
Vol 87 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Raúl Sobrero ◽  
Pedro Fernández-Aburto ◽  
Álvaro Ly-Prieto ◽  
Scarlett E. Delgado ◽  
Jorge Mpodozis ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Right Hemisphere ◽  
Brain Size ◽  
Natural Populations ◽  
Cell Number ◽  
Spatial Behavior ◽  
Population Variation ◽  
Directional Asymmetry ◽  
Male And Female ◽  
The Right

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.

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

2020 ◽  
Author(s):  
Nada Chaari ◽  
Hatice Camgöz Akdağ ◽  
Islem Rekik
Keyword(s):  
Right Hemisphere ◽  
Occipital Cortex ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Network Clustering ◽  
Male And Female ◽  
Clustering Model ◽  
Net Method ◽  
The Right ◽  
Gender Specific

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.

Seating Preference, Hypnotizability, and Imagery Ability

1980 ◽  
Vol 50 (3_suppl) ◽  
pp. 1175-1178 ◽  
Author(s):  
Jacquelyn Cranney ◽  
Kevin M. Mc Conkey
Keyword(s):  
Mental Imagery ◽  
Right Hemisphere ◽  
Imagery Ability ◽  
Hypnotic Susceptibility ◽  
Creative Imagination ◽  
Male And Female ◽  
The Right ◽  
Female Subjects

The effects of a specific hemispheric mode of functioning as indexed by lateralized seating preference was tested separately for male and female subjects in terms of their performance on the Harvard Group Scale of Hypnotic Susceptibility, Form A, the Creative Imagination Scale, and Betts' Questionnaire Upon Mental Imagery. Males, but not females, who preferred right-side seating scored higher on the Harvard scale but not on the Creative Imagination Scale or Betts' imagery questionnaire. Findings provide some support for the notion that hypnotizability is associated with the right hemisphere for right-handed persons.

scholarly journals Length and Depth of the Central Sulcus: A Postmortem Study

2014 ◽  
Vol 11 (1) ◽  
pp. 19-24
Author(s):  
Kanij Fatema ◽  
Shamim Ara ◽  
Mushfika Rahman ◽  
Halima Afroz ◽  
Anjuman Ara Sultana ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Age Groups ◽  
Central Sulcus ◽  
Cross Sectional ◽  
Male And Female ◽  
Significant Difference ◽  
Group A ◽  
The Difference ◽  
Group B ◽  
The Right

Context: The central sulcus, which is located between the primary motor and primary somatic sensory cortex is an important structure and landmark of the cerebral hemisphere. Morphology of the central sulcus varies with age, sex, manual skill, handedness and in many diseases. This study is carried out to establish a normal standard in different age groups in length and depth of the central sulcus. Materials and Methods: A cross-sectional, analytical type of study was conducted in the department of Anatomy, Dhaka Medical College, on one hundred and forty (140) on human cerebral hemispheres. The samples were divided into four different age groups i.e. Group A (20-29 years), Group B (30-39 years), Group C (40-49 years) and Group D (50-59 years). All the samples were studied morphologically. Results: The mean length of central sulcus was 102.89±3.55 mm to 96.83±3.92 mm in male and 98.00±5.17 mm to 96.29±2.56 mm in female. Depth of the central sulcus was 20.02±2.41 mm to 21.50±2.21 mm in male and 20.50±2.57 mm to 21.36±1.87 mm in female. The difference in mean length of the right central sulcus between male and female was statistically significant in group A (p<0.05) and B (p<0.05). The difference in mean depth of the central sulcus between male and female was not statistically significant in any age groups. No significant difference was found between right and left hemisphere for both length and depth of the central sulcus. The difference in mean length and depth of the central sulcus between different age groups for both left and right hemisphere was not statistically significant in any age group. Conclusion: The length and depth of the central sulcus showed gradual decreasing values with advancing age. DOI: http://dx.doi.org/10.3329/bja.v11i1.20504 Bangladesh Journal of Anatomy, January 2013, Vol. 11 No. 1 pp 19-24

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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