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Brain asymmetry

Zhixin Lu, Kevin Klein-Cardeña, Steven Lee, Thomas M Antonsen, Michelle Girvan, Edward Ott
Cells in the brain's Suprachiasmatic Nucleus (SCN) are known to regulate circadian rhythms in mammals. We model synchronization of SCN cells using the forced Kuramoto model, which consists of a large population of coupled phase oscillators (modeling individual SCN cells) with heterogeneous intrinsic frequencies and external periodic forcing. Here, the periodic forcing models diurnally varying external inputs such as sunrise, sunset, and alarm clocks. We reduce the dimensionality of the system using the ansatz of Ott and Antonsen and then study the effect of a sudden change of clock phase to simulate cross-time-zone travel...
September 2016: Chaos
A B Segarra, I Banegas, I Prieto, M Ramirez-Sanchez
INTRODUCTION: Brain asymmetry could be defined as the existence of functional, anatomic or neurochemical differences between both hemispheres. It is a dynamic phenomenon, regulated by endogenous and exogenous factors. Its functional significance is poorly clarified and is only partially understood in very specific cases such as the relationship between the lateralized brain content of dopamine and its motor effects which is specially patent in Parkinson's disease. DEVELOPMENT: The asymmetric brain content of dopamine not only displays lateralized motor effects but also behavioral and autonomic asymmetric consequences...
November 1, 2016: Revista de Neurologia
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No abstract text is available yet for this article.
July 2016: Laterality
F Jagla
It is accepted that the formulation of the motor program in the brain is not only the perceptual and motor function but also the cognitive one. Therefore it is not surprising that the execution of saccadic eye movements can by substantially affected be the on-going mental activity of a given person. Not only the distribution of attention, but also the focusing the attention may influence the main gain of saccades, their accuracy. Patients suffering from mental disorders have strongly engaged their attention focused at their mental processes...
October 24, 2016: Physiological Research
Damien Seth Hunter, Susan J Hazel, Karen L Kind, Hong Liu, Danila Marini, Lynne C Giles, Miles J De Blasio, Julie A Owens, Julia B Pitcher, Kathryn L Gatford
Poor perinatal growth in humans results in asymmetrical grey matter loss in fetuses and infants and increased functional and behavioural asymmetry, but specific contributions of pre- and postnatal growth are unclear. We therefore compared strength and direction of lateralization in obstacle avoidance and maze exit preference tasks in offspring of placentally restricted (PR: 10M, 13F) and control (CON: 23M, 17F) sheep pregnancies at 18 and 40 weeks of age, and examined gross brain structure of the prefrontal cortex at 52 weeks of age (PR: 14M, 18F; CON: 23M, 25F)...
October 19, 2016: Laterality
Nicolas Geades, Benjamin A E Hunt, Simon M Shah, Andrew Peters, Olivier E Mougin, Penny A Gowland
PURPOSE: To develop a method that fits a multipool model to z-spectra acquired from non-steady state sequences, taking into account the effects of variations in T1 or B1 amplitude and the results estimating the parameters for a four-pool model to describe the z-spectrum from the healthy brain. METHODS: We compared measured spectra with a look-up table (LUT) of possible spectra and investigated the potential advantages of simultaneously considering spectra acquired at different saturation powers (coupled spectra) to provide sensitivity to a range of different physicochemical phenomena...
October 17, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Giulia Prete, Mara Fabri, Nicoletta Foschi, Luca Tommasi
We investigated hemispheric asymmetries in categorization of face gender by means of a divided visual field paradigm, in which female and male faces were presented unilaterally for 150 ms each. A group of 60 healthy participants (30 males) and a male split-brain patient (D.D.C.) were asked to categorize the gender of the stimuli. Healthy participants categorized male faces presented in the right visual field (RVF) better and faster than when presented in the left visual field (LVF), and female faces presented in the LVF than in the RVF, independently of the participants' sex...
October 13, 2016: Neuroscience
Jessica C Hodgson, Rebecca J Hirst, John M Hudson
Commonly displayed functional asymmetries such as hand dominance and hemispheric speech lateralisation are well researched in adults. However there is debate about when such functions become lateralised in the typically developing brain. This study examined whether patterns of speech laterality and hand dominance were related and whether they varied with age in typically developing children. 148 children aged 3-10 years performed an electronic pegboard task to determine hand dominance; a subset of 38 of these children also underwent functional Transcranial Doppler (fTCD) imaging to derive a lateralisation index (LI) for hemispheric activation during speech production using an animation description paradigm...
September 29, 2016: Developmental Cognitive Neuroscience
Tulio Guadalupe, Samuel R Mathias, Theo G M vanErp, Christopher D Whelan, Marcel P Zwiers, Yoshinari Abe, Lucija Abramovic, Ingrid Agartz, Ole A Andreassen, Alejandro Arias-Vásquez, Benjamin S Aribisala, Nicola J Armstrong, Volker Arolt, Eric Artiges, Rosa Ayesa-Arriola, Vatche G Baboyan, Tobias Banaschewski, Gareth Barker, Mark E Bastin, Bernhard T Baune, John Blangero, Arun L W Bokde, Premika S W Boedhoe, Anushree Bose, Silvia Brem, Henry Brodaty, Uli Bromberg, Samantha Brooks, Christian Büchel, Jan Buitelaar, Vince D Calhoun, Dara M Cannon, Anna Cattrell, Yuqi Cheng, Patricia J Conrod, Annette Conzelmann, Aiden Corvin, Benedicto Crespo-Facorro, Fabrice Crivello, Udo Dannlowski, Greig I de Zubicaray, Sonja M C de Zwarte, Ian J Deary, Sylvane Desrivières, Nhat Trung Doan, Gary Donohoe, Erlend S Dørum, Stefan Ehrlich, Thomas Espeseth, Guillén Fernández, Herta Flor, Jean-Paul Fouche, Vincent Frouin, Masaki Fukunaga, Jürgen Gallinat, Hugh Garavan, Michael Gill, Andrea Gonzalez Suarez, Penny Gowland, Hans J Grabe, Dominik Grotegerd, Oliver Gruber, Saskia Hagenaars, Ryota Hashimoto, Tobias U Hauser, Andreas Heinz, Derrek P Hibar, Pieter J Hoekstra, Martine Hoogman, Fleur M Howells, Hao Hu, Hilleke E Hulshoff Pol, Chaim Huyser, Bernd Ittermann, Neda Jahanshad, Erik G Jönsson, Sarah Jurk, Rene S Kahn, Sinead Kelly, Bernd Kraemer, Harald Kugel, Jun Soo Kwon, Herve Lemaitre, Klaus-Peter Lesch, Christine Lochner, Michelle Luciano, Andre F Marquand, Nicholas G Martin, Ignacio Martínez-Zalacaín, Jean-Luc Martinot, David Mataix-Cols, Karen Mather, Colm McDonald, Katie L McMahon, Sarah E Medland, José M Menchón, Derek W Morris, Omar Mothersill, Susana Munoz Maniega, Benson Mwangi, Takashi Nakamae, Tomohiro Nakao, Janardhanan C Narayanaswaamy, Frauke Nees, Jan E Nordvik, A Marten H Onnink, Nils Opel, Roel Ophoff, Marie-Laure Paillère Martinot, Dimitri Papadopoulos Orfanos, Paul Pauli, Tomáš Paus, Luise Poustka, Janardhan Yc Reddy, Miguel E Renteria, Roberto Roiz-Santiáñez, Annerine Roos, Natalie A Royle, Perminder Sachdev, Pascual Sánchez-Juan, Lianne Schmaal, Gunter Schumann, Elena Shumskaya, Michael N Smolka, Jair C Soares, Carles Soriano-Mas, Dan J Stein, Lachlan T Strike, Roberto Toro, Jessica A Turner, Nathalie Tzourio-Mazoyer, Anne Uhlmann, Maria Valdés Hernández, Odile A van den Heuvel, Dennis van der Meer, Neeltje E M van Haren, Dick J Veltman, Ganesan Venkatasubramanian, Nora C Vetter, Daniella Vuletic, Susanne Walitza, Henrik Walter, Esther Walton, Zhen Wang, Joanna Wardlaw, Wei Wen, Lars T Westlye, Robert Whelan, Katharina Wittfeld, Thomas Wolfers, Margaret J Wright, Jian Xu, Xiufeng Xu, Je-Yeon Yun, JingJing Zhao, Barbara Franke, Paul M Thompson, David C Glahn, Bernard Mazoyer, Simon E Fisher, Clyde Francks
The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen...
October 13, 2016: Brain Imaging and Behavior
Marlies E van Bochove, Eva Ketel, Miles Wischnewski, Joost Wegman, Esther Aarts, Benjamin de Jonge, W Pieter Medendorp, Dennis J L G Schutter
Research on the hedonic value of food has been important in understanding the motivational and emotional correlates of normal and abnormal eating behaviour. The aim of the present study was to explore associations between hemispheric asymmetries recorded during resting state electroencephalography (EEG) and hedonic valuation of food. Healthy adult volunteers were recruited and four minutes of resting state EEG were recorded from the scalp. Hedonic food valuation and reward sensitivity were assessed with the hedonic attitude to food and behavioural activation scale...
October 8, 2016: International Journal of Psychophysiology
Iris Asllani, Pamelia Slattery, Alexander Fafard, Marykay Pavol, Ronald M Lazar, Randolph S Marshall
Despite being considered an important anatomical parameter directly related to neuronal density, cortical thickness is not routinely assessed in studies of the human brain in vivo. This paucity has been largely due to the size and convoluted shape of the human cortex, which has made it difficult to develop automated algorithms that can measure cortical thickness efficiently and reliably. Since the development of such an algorithm by Fischl and Dale in 2000, the number of studies investigating the relationship between cortical thickness and other physiological parameters in the brain has been on the rise...
2016: NeuroImage: Clinical
Yupeng Wu, Dandan Sun, Yong Wang, Yibao Wang
The definitive structure and functional role of the inferior fronto-occipital fasciculus (IFOF) are still controversial. In this study, we aimed to investigate the connectivity, asymmetry, and segmentation patterns of this bundle. High angular diffusion spectrum imaging (DSI) analysis was performed on 10 healthy adults and a 90-subject DSI template (NTU-90 Atlas). In addition, a new tractography approach based on the anatomic subregions and two regions of interest (ROI) was evaluated for the fiber reconstructions...
2016: Frontiers in Neuroanatomy
Belen Lafon, Asif Rahman, Marom Bikson, Lucas C Parra
BACKGROUND: Direct current stimulation (DCS) affects both neuronal firing rate and synaptic efficacy. The neuronal input/output (I/O) function determines the likelihood that a neuron elicits an action potential in response to synaptic input of a given strength. Changes of the neuronal I/O function by DCS may underlie previous observations in animal models and human testing, yet have not been directly assessed. OBJECTIVE: Test if the neuronal input/output function is affected by DCS METHODS: Using rat hippocampal brain slices and computational modeling, we provide evidence for how DCS modulates the neuronal I/O function...
September 1, 2016: Brain Stimulation
Jesus Minguillon, Miguel A Lopez-Gordo, Francisco Pelayo
Stress assessment has been under study in the last years. Both biochemical and physiological markers have been used to measure stress level. In neuroscience, several studies have related modification of stress level to brain activity changes in limbic system and frontal regions, by using non-invasive techniques such as functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). In particular, previous studies suggested that the exhibition or inhibition of certain brain rhythms in frontal cortical areas indicates stress...
2016: Frontiers in Computational Neuroscience
C Wang, D Ren, Y Guo, Y Xu, Y Feng, X Zhang, Y Mei, M Chen, X Xiao
AIM: To compare intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI)-derived true diffusion (D) and perfusion fraction (f)-values of the two hemispheres to detect the presence of asymmetrical differences. MATERIALS AND METHODS: Forty-seven healthy right-handed volunteers were assessed using IVIM imaging. The interhemispheric D- and f-values were compared using paired t-tests and two related-samples Wilcoxon's test. RESULTS: Comparison of the interhemispheric D- and f-values of the grey matter revealed a significant difference in the D-value of the frontal lobe and the f-value of the temporal lobe (p=0...
October 3, 2016: Clinical Radiology
James Q Truong, Kenneth J Ciuffreda
INTRODUCTION: Little is known about human inter-ocular pupillary asymmetry (IOPA). Thus, the purpose of the present investigation was to assess objectively static and dynamic IOPA in normals and in individuals with mild traumatic brain injury (mTBI). METHODS: The pupillary light reflex (PLR) was assessed in an adult population of normals and in those with mTBI using the Neuroptics DP-2000 binocular pupillometer. Four stimulus conditions were used to optimize the assessment...
August 11, 2016: Brain Injury: [BI]
Roni Kahana-Zweig, Maya Geva-Sagiv, Aharon Weissbrod, Lavi Secundo, Nachum Soroker, Noam Sobel
Nasal airflow is greater in one nostril than in the other because of transient asymmetric nasal passage obstruction by erectile tissue. The extent of obstruction alternates across nostrils with periodicity referred to as the nasal cycle. The nasal cycle is related to autonomic arousal and is indicative of asymmetry in brain function. Moreover, alterations in nasal cycle periodicity have been linked to various diseases. There is therefore need for a tool allowing continuous accurate measurement and recording of airflow in each nostril separately...
2016: PloS One
Yu Guo, Zilong Wang, You Li, Guifeng Wei, Jiao Yuan, Yu Sun, Huan Wang, Qiuhong Qin, Zhijiang Zeng, Shaowu Zhang, Runsheng Chen
In the last decade, it has been demonstrated that brain functional asymmetry occurs not only in vertebrates but also in invertebrates. However, the mechanisms underlying functional asymmetry remain unclear. In the present study, we trained honeybees of the same parentage and age, on the proboscis extension reflex (PER) paradigm with only one antenna in use. The comparisons of gene expression between the left and right hemispheres were carried out using high throughput sequencing. Our research revealed that gene expression in the honeybee brain is also asymmetric, with more genes having higher expression in the right hemisphere than the left hemisphere...
October 5, 2016: Scientific Reports
Sebastian Ocklenburg, Patrick Friedrich, Onur Güntürkün, Erhan Genç
Handedness is thought to originate in the brain, but identifying its structural correlates in the cortex has yielded surprisingly incoherent results. One idea proclaimed by several authors is that structural grey matter asymmetries might underlie handedness. While some authors have found significant associations with handedness in different brain areas (e.g. in the central sulcus and precentral sulcus), others have failed to identify such associations. One method used by many researchers to determine structural grey matter asymmetries is voxel based morphometry (VBM)...
October 28, 2016: Neuroscience Letters
Tahl I Frenkel, Kalsea J Koss, Bonny Donzella, Kristin A Frenn, Connie Lamm, Nathan A Fox, Megan R Gunnar
Individual differences in the propensity for left versus right frontal electroencephalogram (EEG) asymmetry may underlie differences in approach/withdrawal tendencies and mental health deficits. Growing evidence suggests that early life adversity may shape brain development and contribute to the emergence of mental health problems. The present study examined frontal EEG asymmetry (FEA) following the transition to family care in children adopted internationally from institutional care settings between 15 and 36 months of age (N = 82; 46 female, 36 male)...
September 29, 2016: Journal of Abnormal Child Psychology
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