Journal articles on the topic 'Cerebral hemispheres'
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Cronin-Golomb, Alice. "Semantic Networks in the Divided Cerebral Hemispheres." Psychological Science 6, no. 4 (July 1995): 212–18. http://dx.doi.org/10.1111/j.1467-9280.1995.tb00595.x.
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Hemispheric differences in the recognition and manipulation of meaning may be based on distinctions in size, composition, or organization of the right and left semantic networks The present study describes these features of pictorially based semantic networks in 3 subjects with complete forebrain commissurotomy Stimuli were presented for prolonged viewing to the left and right visual hemifields For each trial, the subjects chose from a 20-choice array all pictures that were associated with a target, then indicated the member of each pair of chosen associates that was more closely related to the target The hemispheres' networks were found to be of similar size and composition, but were organized differently The right hemisphere more often produced linear rankings of semantic associates to a target than did the left, and rankings by the two hemispheres were not strongly correlated Hemispheric differences in semantic organization mirror differences in perceptual organization, with the right hemisphere specialized for conventional meaning and the left hemisphere specialized for detecting and processing deviations from standard meaning
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Baybakov, S. E., N. S. Bakhareva, S. V. Chigrin, E. K. Gordeeva, T. R. Yusupov, E. A. Salomatina, and D. D. Shevchuk. "Hemispheric Asymmetry Gender Differences in Preadolescent Children." Innovative Medicine of Kuban, no. 1 (March 6, 2023): 53–57. http://dx.doi.org/10.35401/2541-9897-2023-26-1-53-57.
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Background: Investigating various postnatal parameters of cerebral hemispheres is of great practical value.Objective: To study gender differences in hemispheric parameters and interhemispheric interactions in preadolescent children.Materials and methods: The retrospective study assessed archived brain magnetic resonance images of 60 eight-year-old boys and 60 eight-year-old girls. The analyzed parameters were as follows: 1) hemispheric length; 2) hemispheric width; 3) hemispheric height; 4) width-longitudinal index of a hemisphere; 5) altitude-longitudinal index of a hemisphere; 6) length of frontal lobes; 7) length of parietal lobes; 8) length of occipital lobes; 9) length of temporal lobes. Quantitative indicators were assessed for normal distribution using the Kolmogorov–Smirnov test. Source data were accumulated and arranged in Microsoft Excel 2016 spreadsheets. Statistica 10.0 was used for the statistical analysis. The results were considered statistically significant with P < 0.05.Results: The analysis of cephalometric indicators suggests sex-related variation in the cerebral hemispheres. Based on the obtained data we can identify morphometric parameters of interhemispheric variability that may act as one of the morphometric criteria for the brain asymmetry. The study results can be widely used for neuroimaging.Conclusions: We determined cephalometric reference values for various cerebral hemispheres parts in preadolescent children.
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Kuznetsova, S. M., S. G. Mazur, and M. S. Egorova. "PATHOGENETIC FEATURES OF FUNCTIONAL STATE OF THE BRAIN AND CARDIAC CEREBRAL RELATIONSHIPS IN PATIENTS WITH ATHEROTHROMBOSIS AND CARDIOEMBOLIC STROKE." National Journal of Neurology 2, no. 18 (November 30, 2018): 39–50. http://dx.doi.org/10.61788/njn.v2i18.07.
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The article presents data on the effect of Mexicor in patients who underwent cardioembolic stroke. Thus, Mexicor improves cerebral hemodynamics in Posterior cerebral circulation and causes a reorganization of the structure of brain bioelectrical activity and the type of frequency-amplitude reorganization is determined by the hemispheric localization of the stroke, which may be due to different hemispheres connection with regulating mesencephalic structures and synchronizing diencephalic structures of the brain. In patients with localization of ischemic lesion in the right hemisphere, Mexicor statistically significantly increases the power in the range of α1-, α2-rhythms in the affected and intact hemispheres, which indicates the active influence of the drug on the synchronizing diencephalo-talamic structures of the brain. In patients with localization of ischemic lesion in the left hemisphere, Mexicor predominantly reduces power in the range of slow rhythms and in the range of β2 rhythms in the two hemispheres, which is caused by increased metabolic and functional activity of the mesencephalic stem brain structures. In patients undergoing cardioembolic stroke, Mexicor has a harmonizing effect on the bioelectrical activity of the brain, and improves cerebral hemodynamics, which gives grounds to recommend the use of Mexicor for the rehabilitation of patients who have undergone cardioembolic stroke.
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Jang, Junseok, Sungyeong Ryu, Dong Ah Lee, and Kang Min Park. "Are there network differences between the ipsilateral and contralateral hemispheres of pain in patients with episodic migraine without aura?" Annals of Clinical Neurophysiology 25, no. 2 (October 31, 2023): 93–102. http://dx.doi.org/10.14253/acn.2023.25.2.93.
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Background: We aimed to identif y any differences in the structural covariance network based on structural volume and those in the functional network based on cerebral blood flow between the ipsilateral and contralateral hemispheres of pain in patients with episodic migraine without aura.Methods: We prospectively enrolled 27 patients with migraine without aura, all of whom had unilateral migraine pain. We defined the ipsilateral hemisphere as the side of migraine pain. We measured structural volumes on three-dimensional T1-weighted images and cerebral blood flow using arterial spin labeling magnetic resonance imaging. We then analyzed the structural covariance network based on structural volume and the functional network based on cerebral blood flow using graph theory. Results: There were no significant differences in structural volume or cerebral blood flow between the ipsilateral and contralateral hemispheres. However, there were significant differences between the hemispheres in the structural covariance network and the functional network. In the structural covariance network, the betweenness centrality of the thalamus was lower in the ipsilateral hemisphere than in the contralateral hemisphere. In the functional network, the betweenness centrality of the anterior cingulate and paracingulate gyrus was lower in the ipsilateral hemisphere than in the contralateral hemisphere, while that of the opercular part of the inferior frontal gyrus was higher in the former hemisphere.Conclusions: The present findings indicate that there are significant differences in the structural covariance network and the functional network between the ipsilateral and contralateral hemispheres of pain in patients with episodic migraine without aura.
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Trach, О. О., D. M. Shyian, and D. I. Marakushin. "Individual variability of the brain hemispheres’ and occipital lobes’ width." Medicine Today and Tomorrow 88, no. 3 (October 1, 2020): 4–11. http://dx.doi.org/10.35339/msz.2020.88.03.01.
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200 hemispheres of the brain of people who died from diseases not related to brain pathology were studied. Morphometric method was used and statistical analysis was completed. It was found out that the width of the right and left hemispheres of the brain in both men and women of brachycranial skull type is slightly greater than of mesocranial and dolichocranial ones. Men and women with dolichocranial skull type have the width of the left hemisphere greater than the right one. Men have the width of the left and right hemispheres greater than women. The limits of individual variability of brain hemispheres’ and occipital lobes’ width have been determined taking into account the type of skull and sex. The largest indicators of the cerebral hemispheres’ width are the next: men of the brachycranial skull type have the right hemisphere’s width of the 70.6•10^-3 m, left one of the 71.4•10^3 m width; the women of the brachycranial skull type have the right hemispheres’ width of the 63.4•10^-3 m and the left one of the 63.8•10^3 m, the women of the mesocranial skull type have the left hemisphere’s width of 63.7•10^3 m. The smallest indicators of the cerebral hemispheres’ width are: men of the dolichocranial skull type have the width of the right hemisphere 44•10^3 m, of the left one of the dolichocranial skull type and of the brachycranial skull type have the width 43.8•10^3 m; women of the dolichocranial skull type have the width of the right hemisphere 38.5•10^3 m, left one of 42.5•10^-3. The largest indicators of the occipital lobes’ width are: men of the brachycranial skull type have the width of the right hemisphere 56•10^3 m, men of the mesocranial skull type have the width of the left hemisphere 65•10^3 m; women of the dolichocranial skull type have the right hemispheres’ width 58•10^-3 m, of mesocranial skull type have the left one is of 63•10^-3 m and of dolichocranial it is of 62.5•10^3 m. The smallest indicators of the occipital lobes’ width are: men of the dolichocranial skull type have the width of the right lobe 41•10^3 m, of mesocranial and brachycranial types it is 42•10^3 m, the width of the left lobe in men with dolichocranial skull type of 38•10^3 m; women of the mesocranial skull type have the right lobe’s width of 36•10^3 m, the left one of dolichocranial skull type it is of 34•10^-3 m. Keywords: endbrain, occipital lobe, individual anatomical variability.
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Trushina, D. A., O. A. Vedyasova, and M. A. Paramonova. "SPATIAL PICTURE OF DISTRIBUTION OF ELECTROENCEPHALOGRAM RHYTHMS IN THE RIGHT-HANDED STUDENTS DURING AN EXAM." Vestnik of Samara University. Natural Science Series 20, no. 3 (May 31, 2017): 202–12. http://dx.doi.org/10.18287/2541-7525-2014-20-3-202-212.
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Registration of electroencephalogram (EEG) in the right-handed students during an exam revealed weakening of alpha rhythm in all areas of right and left cerebral hemispheres as well as increased beta rhythm in parietal and end-lobes of the right hemisphere. Simultaneously regular delta waves in the frontal leads ofboth hemispheres and theta waves in right frontal, occipitalis and temporal leads were marked. Offset of EEG slow wave activity in the right hemisphere in partial right-handers was marked in more noticeable way than in that of the true right-handers. The obtained data suggest that the distribution of EEG rhythms in condition of mental and emotional stress in right-handers depends on the type and severity of functional hemispheric asymmetry.
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Williams, Stephen. "The Cerebral Hemispheres as a Mapping System." Psychological Reports 63, no. 1 (August 1988): 208–10. http://dx.doi.org/10.2466/pr0.1988.63.1.208.
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One version of an orthodox rationale for psychological studies of functional hemispheric asymmetry is sketched out. This rationale emphasizes the significance of asymmetry for a psychological taxonomy. An alternative rationale is then presented. This is that the arrangement of the hemispheres with their commissures permits mapping between hemispheres. This mapping may underlie human capacities such as abstraction.
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Long, Debra L., and Kathleen Baynes. "Discourse Representation in the Two Cerebral Hemispheres." Journal of Cognitive Neuroscience 14, no. 2 (February 1, 2002): 228–42. http://dx.doi.org/10.1162/089892902317236867.
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Readers construct at least two interrelated representations when they comprehend a text: (a) a propositional representation containing the individual ideas that are derived from each sentence and the relations among them and (b) a discourse model, a representation of the context or situation to which the text refers. We used a paradigm called “item priming in recognition” to examine how these representations are stored in the cerebral hemispheres. In Experiment 1, the priming paradigm was used in combination with a lateralized visual field (VF) procedure. We found evidence that readers' representations were structured according to propositional relations, but only in the left hemisphere. Item recognition was facilitated when a concept was preceded by another concept from the same proposition when targets were presented to the left, but not to the right, hemisphere. We found priming in both hemispheres, however, when targets were context-appropriate senses of ambiguous words or topics of passages. In Experiment 2, we replicated the priming effects in three callosotomy patients. We argue that the distinction between a propositional representation and a discourse model is important with respect to how discourse is represented in the brain. The propositional representation appears to reside in the left hemisphere, whereas aspects of the discourse model appear to be represented in both hemispheres.
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Ikkert, Oksana, and Tetiana Korol. "CEREBRAL HEMISPHERES FUNCTIONAL ASYMMETRY IN THE EDUCATION OF NATURAL SPECIALTIES AND HUMANITIES STUDENTS." Scientific Journal of Polonia University 58, no. 3 (September 1, 2023): 90–97. http://dx.doi.org/10.23856/5813.
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The functional asymmetry of the human brain hemispheres (motor, sensory and mental) reflects the difference in the distribution of neuropsychological functions between its right and left hemispheres. Both hemispheres are involved in the implementation of any types of mental activity or regulation of vegetative physiological processes, but each of them provides different aspects of this activity and some processes domination. Persons with left-hemisphere and right-hemisphere thinking differ in the features of perception, analysis, and reproduction of information, which is important in the process of students' educational activities. That is why the aim of this investigation was to conduct a comparative analysis of the types of the brain hemispheres dominance in students of natural and humanities education who study at the biological and philosophical faculties of the Ivan Franko National University of Lviv and proposed methodological approaches for development and activation both (left and right) brain hemispheres. Methods used in the study: determining the coefficient of functional asymmetry of the brain; general scientific (analysis and synthesis), methods of theoretical research (from abstract to concrete). It was shown that most of the student are dominated by the left brain hemisphere but organizing of the educational process needs to use methods of educational activities aimed at the development and activation both (left and right) brain hemispheres.
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Swanson, Larry W., Olaf Sporns, and Joel D. Hahn. "Network architecture of the cerebral nuclei (basal ganglia) association and commissural connectome." Proceedings of the National Academy of Sciences 113, no. 40 (September 19, 2016): E5972—E5981. http://dx.doi.org/10.1073/pnas.1613184113.
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The cerebral nuclei form the ventral division of the cerebral hemisphere and are thought to play an important role in neural systems controlling somatic movement and motivation. Network analysis was used to define global architectural features of intrinsic cerebral nuclei circuitry in one hemisphere (association connections) and between hemispheres (commissural connections). The analysis was based on more than 4,000 reports of histologically defined axonal connections involving all 45 gray matter regions of the rat cerebral nuclei and revealed the existence of four asymmetrically interconnected modules. The modules form four topographically distinct longitudinal columns that only partly correspond to previous interpretations of cerebral nuclei structure–function organization. The network of connections within and between modules in one hemisphere or the other is quite dense (about 40% of all possible connections), whereas the network of connections between hemispheres is weak and sparse (only about 5% of all possible connections). Particularly highly interconnected regions (rich club and hubs within it) form a topologically continuous band extending through two of the modules. Connection path lengths among numerous pairs of regions, and among some of the network’s modules, are relatively long, thus accounting for low global efficiency in network communication. These results provide a starting point for reexamining the connectional organization of the cerebral hemispheres as a whole (right and left cerebral cortex and cerebral nuclei together) and their relation to the rest of the nervous system.
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Shibahara, Naoki, and Brennis Lucero-Wagoner. "Access to Concrete Word Meanings in the Cerebral Hemispheres: Facilitation and Inhibition Effects." Perceptual and Motor Skills 96, no. 1 (February 2003): 166–72. http://dx.doi.org/10.2466/pms.2003.96.1.166.
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In 2002 Shibahara and Lucero-Wagoner, using a priming paradigm, reported a larger facilitation for concrete noun pairs in the right than left hemisphere when the stimulus onset asynchrony was 250 msec. Their related prime-target pairs were similar not only in meaning but also perceptual attributes, such as shape. They had reported such perceptual information to be available only in the right hemisphere early in target processing. Thus, we predicted that, when the stimulus onset asynchrony is long, there would be no effect of perceptual information on target processing in the right hemisphere, resulting in no hemispheric differences in the amount of facilitation. We also predicted that target processing would be inhibited by prior presentation of unrelated primes only in the left hemisphere because inhibition seems to be produced by the attention system in the left hemisphere. The present experiment was designed to test these predictions, using the stimulus onset asynchrony of 550 msec. and the same prime-target pairs. Analysis showed no hemispheric differences in the amount of facilitation, and inhibition effects for unrelated pairs were produced in both hemispheres. It is suggested that the inhibition effects in each hemisphere might be produced by different mechanisms.
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Schwartz, Theodore H., Michael M. Haglund, Ettore Lettich, and George A. Ojemann. "Asymmetry of Neuronal Activity During Extracellular Microelectrode Recording from Left and Right Human Temporal Lobe Neocortex During Rhyming and Line-Matching." Journal of Cognitive Neuroscience 12, no. 5 (September 2000): 803–12. http://dx.doi.org/10.1162/089892900562615.
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Recordings of neuronal activity in humans have identified few correlates of the known hemispheric asymmetries of functional lateralization. Here, we examine single-unit activity recorded from both hemispheres during two delayed match-to-sample tasks that show strong hemispheric lateralization based on lesion effects; a line-matching (LM) task related to the right hemisphere, and a rhyming (RHY) task related to the left. Nineteen neuronal populations were recorded with extracellular microelectrodes from the left temporal neocortex of 11 awake patients, and 18 from the right in 9 patients during anterior temporal lobectomy for complex partial seizures under local anesthesia. All subjects were left hemisphere dominant for language. Twelve (32%) populations exhibited statistically significant changes in activity at p < .05. Although changes in firing frequency were recorded from both hemispheres during both tasks, the RHY task elicited changes in activity several hundred milliseconds earlier on the left side than on the right. The LM task, on the other hand, induced changes earlier on the right side than on the left. Both hemispheres contained units active during verbal responses regardless of which behavior elicited the response. Our results indicate that cerebral dominance is reflected in earlier neuronal activity in the anterior temporal lobe during tasks lateralized to that hemisphere.
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Dantas, Fábio Galvão, André Pinto Cavalcanti, Bruno Diego Rodrigues Maciel, Clarissa Dantas Ribeiro, Gabriella Carvalho Napy Charara, Johnnatas Mikael Lopes, Paulo Fernando Martins Filho, and Luiz Ataíde Júnior. "Hemispheric assymetry of abnormal focal EEG findings." Journal of Epilepsy and Clinical Neurophysiology 17, no. 2 (2011): 43–48. http://dx.doi.org/10.1590/s1676-26492011000200003.
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Left and right cerebral hemispheres are morphologically similar, although they are functionally different. Focal EEG abnormalities should appear with an equal frequency in both of them, but the literature has reported a left predominance. We presented the first Latin American study on lateralization of focal EEG abnormalities. METHOD: We retrospectively studied 10,408 EEGs from April 2001 to April 2010. They were separated by age and gender to estimate the frequency of left-sided versus right-sided focal abnormalities (discharges or slow waves). Associated clinical features were also accessed. RESULTS: Discharges were more prevalent in left cerebral hemisphere, in temporal lobe, and a stronger lateralization was found among adults. Right-sided discharges occurred more in frontal lobe. Slow waves were also more prevalent in the left cerebral hemisphere and among adults. Among left-sided slow waves group, women were more prevalent. Contrarily, men were more observed among right-sided slow waves EEGs. Left-sided slow waves were more prevalent in temporal and parietal lobes. Contrarily, right-sided slow waves occurred more in frontal and occipital lobes. Epilepsy was the most frequent disease among the patients with focal discharges in both cerebral hemispheres. Right-sided slow waves were more associated to epilepsy, and left-sided slow waves were more associated to headache. CONCLUSION: There were significant differences between cerebral hemispheres on focal EEG abnormalities, considering lateralization, gender, age and clinical features. These results suggest a neurofuncional asymmetry between cerebral hemispheres which may be explained by different specificities, as well as by cerebral neuroplasticity.
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PINTO JR, LUCIANO RIBEIRO, ADEMIR BAPTISTA SILVA, and SERGIO TUFIK. "Rapid eye movements during paradoxical sleep in patients with cerebrovascular disease." Arquivos de Neuro-Psiquiatria 58, no. 2A (June 2000): 239–45. http://dx.doi.org/10.1590/s0004-282x2000000200006.
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Rapid eye movements that occur during paradoxical sleep are generated from the brainstem and are modulated by cerebral hemispheres. In an attempt to establish the participation of cerebral hemispheres on rapid eye movements, we carried out a quantitative study of eye movements density in patients bearing hemispheres vascular lesions. The polysomnographic recordings of 24 patients were compared to those of 24 healthy volunteers. Density of rapid eye movements was defined as the porcentage of eye movements during the respective time of paradoxical sleep. Based on the present results, we concluded that: stroke patients with hemispheric lesions displayed increased density of rapid eye movements; there was no difference on the density of rapid eye movements according to the hemispheric lesion; higher density of rapid eye movements was observed in patients with anterior hemispheric lesion.
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Buffon, Frédérique, Nicolas Molko, Dominique Hervé, Raphaël Porcher, Isabelle Denghien, Sabina Pappata, Denis Le Bihan, Marie-Germaine Bousser, and Hugues Chabriat. "Longitudinal Diffusion Changes in Cerebral Hemispheres after MCA Infarcts." Journal of Cerebral Blood Flow & Metabolism 25, no. 5 (February 2, 2005): 641–50. http://dx.doi.org/10.1038/sj.jcbfm.9600054.
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Diffusion tensor imaging can be used in vivo to assess the longitudinal and regional microstructural changes occurring after middle cerebral artery (MCA) infarcts in humans. Nine patients were investigated 1 week (D7), 1 (M1), 3 (M3), and 6 months (M6) after the occurrence of an isolated MCA infarction. First, an overall analysis was performed using histograms of mean diffusivity (MD) and fractional anisotropy (FA) in each hemisphere. Thereafter, the regional pattern of diffusion changes was investigated voxel by voxel with statistical parametric mapping 99. In the hemisphere ipsilateral to the infarction, histogram analysis revealed a significant decrease in FA between D7 and M6 associated with a progressive increase in MD from D7 to M3. Remote from the MCA territory, the voxel by voxel analyses detected a significant increase in MD within the thalamus at M3 and M6 and a reduction in FA along the pyramidal tract at M6. In the contralateral hemisphere, between D7 and M6, a significant hemispheric atrophy was observed in association with a global reduction in anisotropy, in the absence of distinctive regional diffusion changes. These results suggest that micro- and macrostructural tissue modifications can be detected with diffusion tensor imaging in regions remote from the ischemic area in both hemispheres.
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Pandian, Muthuchitra, Anjali Sabnis, and Shroff Gautam. "Anatomical variations of sulci in human fetal cerebrum and its clinical significance." Biomedicine 41, no. 3 (October 29, 2021): 539–42. http://dx.doi.org/10.51248/.v41i3.691.
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Introduction and Aim: Appearance of sulci and its number in the fetal cerebrum is a signal of growth and development. Chronological appearance and symmetrical development of sulci corresponds to gestational age of fetus. Few sulci can be visualized in the prenatal period to judge the growth of fetus. Any change in chronological appearance, symmetry and number of sulci in fetal cerebrum is of prime importance. Materials and Methods: Hundred and six cerebral hemispheres of 53 fetal brains of different gestational ages were collected from MGM Hospital Kalamboli and Aurangabad after institutional ethical approval to study the pattern of sulci on both sides after fixing in 10% formalin. Results: In 6 (5.6 %) cerebral hemispheres variation in appearance of sulci was observed. It was noted that there is change in number of superior temporal sulcus (STS), superior frontal sulcus (SFS), parieto-occipital sulcus (POS), calcarine sulcus (CS) and occipitotemporal sulcus (OTS) on both the sides in 6 cerebral hemispheres. Remaining 100 cerebral hemisphere showed normal, symmetrical appearance and number of sulci. Conclusion: It was observed that the fetal cerebral hemispheres which showed variations in appearance and number of sulci were associated with mother having eclampsia.
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Motz, Benjamin A., Karin H. James, and Thomas A. Busey. "The Lateralizer: a tool for students to explore the divided brain." Advances in Physiology Education 36, no. 3 (September 2012): 220–25. http://dx.doi.org/10.1152/advan.00060.2012.
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Despite a profusion of popular misinformation about the left brain and right brain, there are functional differences between the left and right cerebral hemispheres in humans. Evidence from split-brain patients, individuals with unilateral brain damage, and neuroimaging studies suggest that each hemisphere may be specialized for certain cognitive processes. One way to easily explore these hemispheric asymmetries is with the divided visual field technique, where visual stimuli are presented on either the left or right side of the visual field and task performance is compared between these two conditions; any behavioral differences between the left and right visual fields may be interpreted as evidence for functional asymmetries between the left and right cerebral hemispheres. We developed a simple software package that implements the divided visual field technique, called the Lateralizer, and introduced this experimental approach as a problem-based learning module in a lower-division research methods course. Second-year undergraduate students used the Lateralizer to experimentally challenge and explore theories of the differences between the left and right cerebral hemispheres. Measured learning outcomes after active exploration with the Lateralizer, including new knowledge of brain anatomy and connectivity, were on par with those observed in an upper-division lecture course. Moreover, the project added to the students' research skill sets and seemed to foster an appreciation of the link between brain anatomy and function.
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Kim, Dae Hyun, and Hyunkoo Kang. "Changes in Bihemispheric Structural Connectivity Following Middle Cerebral Artery Infarction." Journal of Personalized Medicine 12, no. 1 (January 10, 2022): 81. http://dx.doi.org/10.3390/jpm12010081.
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This study investigated the changes in the structural connectivity of the bilateral hemispheres over time following a middle cerebral artery infarction. Eighteen patients in the subacute group and nine patients in the chronic group with mild upper extremity motor impairment (Fugl-Meyer motor assessment score for the upper limb > 43) following middle cerebral artery infarction were retrospectively evaluated in this study. All the patients underwent T1-weighted and diffusion tensor imaging. Tract-based statistical analyses of fractional anisotropy were used to compare the changes in the bilateral structural connectivity with those of age-matched normal controls. The corticospinal tract pathway of the affected hemisphere, corpus callosum, and corona radiata of the unaffected hemisphere had decreased structural connectivity in the subacute group, while the motor association area and anterior corpus callosum in the bilateral frontal lobes had increased structural connectivity in the chronic group. The bilateral hemispheres were influenced even in patients with mild motor impairment following middle cerebral artery infarction, and the structural connectivity of the bilateral hemispheres changed according to the time following the stroke.
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Lobel, Daniel S., Rex M. Swanda, and Miklos F. Losonczy. "Lateralized Visual-Field Inattention in Schizophrenia." Perceptual and Motor Skills 79, no. 1 (August 1994): 699–702. http://dx.doi.org/10.2466/pms.1994.79.1.699.
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Numerous studies have shown impaired verbal functioning in schizophrenic patients as compared with normals. The verbal deficits are generally attributed to damage of the left cerebral hemisphere. This attribution is based on literature which suggests that verbal processing is primarily mediated by the left hemisphere in right-handed humans. This study explored left-hemispheric integrity directly by assessing sustained attention in both the left and right hemispheres of 40 schizophrenic patients with the Weintraub Cancellation Tasks. Patients made significantly more errors of omission on the right visual field than on the left. These results are consistent with cognitive research in schizophrenia by demonstrating selective left-hemispheric impairment relative to right-hemispheric functioning.
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Nishizawa, Taketo, Miki Fujimura, Masahito Katsuki, Shunji Mugikura, Ryosuke Tashiro, Kenichi Sato, and Teiji Tominaga. "Prediction of Cerebral Hyperperfusion after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis by Three-Dimensional-Time-of-Flight Magnetic Resonance Angiography in Adult Patients with Moyamoya Disease." Cerebrovascular Diseases 49, no. 4 (2020): 396–403. http://dx.doi.org/10.1159/000509740.
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Introduction: Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is an effective surgical procedure for adult patients with moyamoya disease (MMD) and is known to have the potential to prevent cerebral ischemia and/or hemorrhagic stroke. Cerebral hyperperfusion (CHP) syndrome is one of the serious complications of this procedure that can result in deleterious outcomes, such as delayed intracerebral hemorrhage, but the prediction of CHP before revascularization surgery remains challenging. The present study evaluated the diagnostic value of preoperative three-dimensional (3D)-time-of-flight (TOF) magnetic resonance angiography (MRA) for predicting CHP after STA-MCA anastomosis for MMD. Materials and Methods: The signal intensity of the peripheral portion of the intracranial major arteries, such as the anterior cerebral artery (ACA), MCA, and posterior cerebral artery (PCA) ipsilateral to STA-MCA anastomosis, on preoperative MRA was graded (0–2 in each vessel) according to the ability to visualize each vessel on 97 affected hemispheres in 83 adult MMD patients. Local cerebral blood flow (CBF) at the site of anastomosis was quantitatively measured by N-isopropyl-p-[123I]-iodoamphetamine single-photon emission computed tomography 1 and 7 days after surgery, in addition to the preoperative CBF value at the corresponding area. Then, we investigated the correlation between the preoperative MRA score and the development of CHP. Results: The CHP phenomenon 1 day after STA-MCA anastomosis (local CBF increase over 150% compared with the preoperative value) was evident in 27 patients (27/97 hemispheres; 28%). Among them, 8 (8 hemispheres) developed CHP syndrome. Multivariate analysis revealed that the hemispheric MRA score (0–6), the summed ACA, MCA, and PCA scores for the affected hemisphere, was significantly associated with the development of CHP syndrome (p = 0.011). The hemispheric MRA score was also significantly correlated with the CHP phenomenon, either symptomatic or asymptomatic (p < 0.001). Conclusion: The signal intensity of the intracranial major arteries, including the ACA, MCA, and PCA, on preoperative 3D-TOF MRA may identify adult MMD patients at higher risk for CHP after direct revascularization surgery.
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Doty, Robert. "Unity from duality." Acta Neurobiologiae Experimentalis 63, no. 3 (September 30, 2003): 163–70. http://dx.doi.org/10.55782/ane-2003-1464.
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When, in the primeval sea, creatures first began to crawl, "right" and "left" came into being, yielding neuronal nets to control response to the sidedness of stimuli. In the half billion years of moving and sensing, two brains have evolved, the right and the left; and human experience now shows them to be roughly equivalent, potentially independent, conscious entities. This dramatic fact is evidenced by "split-brain" patients and by numerous cases of therapeutic removal of either hemisphere. Equally dramatic, of course, is that there is not the slightest sign of this duality in everyday experience, the right and left visual fields are seamlessly knit, and cross purpose is absent in the moment to moment operation of the two cerebral hemispheres. This unity is constantly synthesized by the 100,000,000 fibers passing from each hemisphere to the other; the vastness of that interchange emphasized upon comparison with the mere 1,000,000 fibers conveying all the visual world from each eye. With the large distances in the human brain some 100+ ms may commonly transpire for one hemisphere to send to and receive a response from the other. Efficiency thus demands that most neuronal calculation occur within rather than between hemispheres, thereby promoting differences in the characteristic capabilities of each alone, i.e., "hemispheric specialization". Despite this there is a bewildering bilaterality of activation revealed by fMRI for most cognitive tasks. In the absence of the forebrain commissures brainstem systems can be shown, in macaques, also to participate in the unification of behavioral result from the actions of the separated hemispheres. The system favors synthesis from congruent (visual) input to the two hemispheres; but in the face of incompatible hemispheric input, the two hemispheres are able to work out an accommodation in their control of subcortical systems.
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Joukamaa, M. "Alexithymia and cerebral hemispheres." European Psychiatry 17 (May 2002): 81. http://dx.doi.org/10.1016/s0924-9338(02)80374-1.
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Frolova, L. S., Yu O. Petrenko, A. A. Tymofeev, P. M. Gunko, O. V. Okhrimenko, and R. M. Khaliavka. "Technical readiness of young basketball players with different profile of functional asymmetry." Pedagogics, psychology, medical-biological problems of physical training and sports 23, no. 3 (June 29, 2019): 132–37. http://dx.doi.org/10.15561/18189172.2019.0304.
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Purpose The functional asymmetry is considered to be the basis of psycho physiological individual features of young basketball players. It indicates the dominant hemisphere while processing information concerning the precision in body movement in basketball playing technique. The research concerning the cerebral hemispheres asymmetry influence on the movement technique formation of young basketball players is still highly inconsistent. Therefore, the study aims at the determining technical readiness peculiarities of basketball players aged 12-13 with different cerebral asymmetry profiles while performing exercises with dominant and sub-dominant hands. Material 35 basketball players aged 12-13 have been tested in order to determine the type of cerebral asymmetry and technical readiness. To determine the cerebral asymmetry, the computer modified test of Stroop was used. In order to define technical readiness, three exercises which are performed using the right and left hand have been developed. Results Half of the group of basketball players aged 12-13 do not have a clear lateralization of the hemispheres: 51% of participants have symmetry of the hemispheres, 28% - the functional activity of the right hemisphere, and 20% - the left hemisphere activity. The study showed that shots of basketball players with the left cerebral lateralization are more accurate when performed with dominant hand. They prevail in the speed and accuracy parameters of passing and dribbling with both hands as well. Conclusions The many-sided nature of the interhemispheric asymmetry of basketball players aged 12-13 was determined. Its influence on technical readiness was found out. The highest level of technical readiness has been found among basketball players with the left hemisphere dominance. The lowest level of technical readiness was recorded among basketball players with the right hemisphere dominance. It was specified, that at the age of 12-13, the bimanual character of movements of young basketball players with left hemisphere dominance is being formed more actively.
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Piechnik, Stefan K., Marek Czosnyka, Neil G. Harris, Pawan S. Minhas, and John D. Pickard. "A Model of the Cerebral and Cerebrospinal Fluid Circulations to Examine Asymmetry in Cerebrovascular Reactivity." Journal of Cerebral Blood Flow & Metabolism 21, no. 2 (February 2001): 182–92. http://dx.doi.org/10.1097/00004647-200102000-00010.
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The authors examined the steal phenomenon using a new mathematical model of cerebral blood flow and the cerebrospinal fluid circulation. In this model, the two hemispheres are connected through the circle of Willis by an anterior communicating artery (ACoA) of varying size. The right hemisphere has no cerebrovascular reactivity and the left is normally reactive. The authors studied the asymmetry of hemispheric blood flow in response to simulated changes in arterial blood pressure and carbon dioxide concentration. The hemispheric blood flow was dependent on the local regulatory capacity but not on the size of the ACoA. Flow through the ACoA and carotid artery was strongly dependent on the size of the communicating artery. A global interhemispheric “steal effect” was demonstrated to be unlikely to occur in subjects with nonstenosed carotid arteries. Vasoreactive effects on intracranial pressure had a major influence on the circulation in both hemispheres, provoking additional changes in blood flow on the nonregulating side. A method for the quantification of the crosscirculatory capacity has been proposed.
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Hachinski, Vladimir C., Mortimer Mamelak, and John W. Norris. "Clinical Recovery and Sleep Architecture Degradation." Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 17, no. 3 (August 1990): 332–35. http://dx.doi.org/10.1017/s0317167100030699.
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ABSTRACT:We achieved a unique and timely recording of cerebral activity in a 70 year old woman immediately pre- and post-stroke, while studying the effect of acute cerebral infarction on sleep-electroencephalogram (EEG) patterns. Normal patterns, except for increased wakefulness, were recorded during two pre-infarct polysomnograms. Immediately following cerebral infarction increased delta activity was recorded from the infarcted hemisphere only. Initially, REM sleep could not be recorded from either side; however, on the third post infarct day REM sleep returned. Background EEG levels from both hemispheres became progressively slower, flatter and simpler. In addition, sleep spindles and the distinctive saw-tooth wave forms of sleep almost disappeared. At one year post-stroke sleep-EEG rhythm recordings from both hemispheres became more similar except for persisting delta activity from the left hemisphere. Unexpected deterioration of sleep-EEG pattern recordings from the undamaged hemisphere taken during the patient's clinical recovery remains unexplained. Serial sleep recording may facilitate the study of brain recovery, activity and reorganization following stroke.
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Liu, He, Yezhong Tang, Yanxia Ni, and Guangzhan Fang. "Laterality in Responses to Acoustic Stimuli in Giant Pandas." Animals 11, no. 3 (March 11, 2021): 774. http://dx.doi.org/10.3390/ani11030774.
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Cerebral lateralization is a common feature present in many vertebrates and is often observed in response to various sensory stimuli. Numerous studies have proposed that some vertebrate species have a right hemisphere or left hemisphere dominance in response to specific types of acoustic stimuli. We investigated lateralization of eight giant pandas (Ailuropoda melanoleuca) by using a head turning paradigm and twenty-eight acoustic stimuli with different emotional valences which included twenty-four conspecific and four non-conspecific acoustic stimuli (white noise, thunder, and vocalization of a predator). There was no significant difference in auditory laterality in responses to conspecific or non-conspecific sounds. However, the left cerebral hemisphere processed the positive stimuli, whereas neither of the two hemispheres exhibited a preference for processing the negative stimuli. Furthermore, the right hemisphere was faster than the left hemisphere in processing emotional stimuli and conspecific stimuli. These findings demonstrate that giant pandas exhibit lateralization in response to different acoustic stimuli, which provides evidence of hemispheric asymmetry in this species.
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Сеинова and L. Seinova. "A comparative analysis of cerebral asymmetry according to data from perfusion computed tomography in infarctions of the cerebral hemispheres and dyscirculatory encephalopathy." Journal of New Medical Technologies. eJournal 9, no. 4 (December 8, 2015): 0. http://dx.doi.org/10.12737/16770.
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Currently a problem of timely diagnostics and treatment of disorders of cerebral circulation is one of the most important for medicine, as strokes and chronic brain ischemia occupy a significant place among the diseases leading to mortality and disability of population. Computed tomography is one of the leading diagnostics of cerebro-vascular disorders. Today, the diagnostic capabilities of perfusion computed tomography, especially in the field of subtle changes in perfusion in infected and in the contralateral hemispheres of the brain are poorly understood and aren’t used in full. The relevance and scientific novelty of this research is not in doubt. Based on the data of 87 patients with ischemic infarction of the cerebral hemispheres of the brain and vascular encephalopathy, a comparative analysis of blood flow in the affected and contralateral hemispheres, was carried out. The degree of asymmetry of blood flow depending on the phase of development of ischemic stroke and chronic brain ischemia was evaluated. The studies have shown that the relative indicator of inter-hemispheric asymmetry is reduced in the course of development of cerebral infarction, reaching minimum values of dyscirculatory encephalopathy. The author substantiates the practical use of the proposed indicator of inter-hemispheric asymmetry in the evaluation of the degree of chronic ischemic disturbances of cerebral blood flow.
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Barker, W. W., F. Yoshii, D. A. Loewenstein, J. Y. Chang, A. Apicella, Shlomo Pascal, T. E. Boothe, M. D. Ginsberg, and R. Duara. "Cerebrocerebellar Relationship during Behavioral Activation: A PET Study." Journal of Cerebral Blood Flow & Metabolism 11, no. 1 (January 1991): 48–54. http://dx.doi.org/10.1038/jcbfm.1991.5.
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The effect of behavioral activation on cerebral and cerebellar glucose metabolism was studied in normal subjects when performing either a verbal memory task or a tactile somatosensory task. Each subject was also studied in a resting state control condition, either 1 h earlier or later than the activation task. Compared to the resting state, both tasks produced asymmetrical metabolic activation, which was opposite in direction within the cerebral and cerebellar hemispheres. In both tasks, the difference of activation of CMRglc in the right and left hemispheres in the cerebellum was negatively correlated with that in the sensory-motor region. This apparently coupled metabolic activation of one cerebellum and areas within the opposite cerebral hemisphere represents the inverse of the crossed cerebellar diaschisis phenomenon commonly observed when a vascular lesion affects one cerebral hemisphere and hypometabolism occurs in the opposite cerebellum. Because these correlations were selective and concordant with known anatomical connections, and were found in two different tasks, they suggest strong functional connections between these specific brain regions.
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Pilipenko, Vladimirs, Zane Dzirkale, Rebeka Rozkalne, Jolanta Upite, Farida Hellal, Nikolaus Plesnila, and Baiba Jansone. "Focal Cerebral Ischemia Induces Global Subacute Changes in the Number of Neuroblasts and Neurons and the Angiogenic Factor Density in Mice." Medicina 59, no. 12 (December 14, 2023): 2168. http://dx.doi.org/10.3390/medicina59122168.
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Background and Objectives: Dissecting the complex pathological cascade of an ischemic stroke in preclinical models is highly warranted to understand the course of this disease in humans. Neurogenesis and angiogenesis are integral for post-stroke recovery, yet it is not clear how these processes are altered months after an ischemic stroke. In this study, we investigated the changes that take place subacutely after focal cerebral ischemia in experimental adult male mice. Materials and Methods: Male 12-week-old C57BL/6 mice underwent a 60 min long fMCAo or sham surgery. Two months after the procedure, we examined the immunohistochemistry to assess the changes in neuroblast (DCX) and differentiated neuron (NeuN) numbers, as well as the density of the pro-angiogenic factor VEGF. Results: We found decreased neuroblast numbers in both brain hemispheres of the fMCAo mice: by more than 85% in the dentate gyrus and by more than 70% in the subventricular zone. No neuroblasts were found in the contralateral hemisphere of the fMCAO mice or the sham controls, but a small population was detected in the ipsilateral ischemic core of the fMCAo mice. Intriguingly, the number of differentiated neurons in the ipsilateral ischemic core was lower by 20% compared to the contralateral hemisphere. VEGF expression was diminished in both brain hemispheres of the fMCAo mice. Conclusions: Our current report shows that focal cerebral ischemia induces changes in neuroblast numbers and the pro-angiogenic factor VEGF in both cerebral hemispheres 2 months after an fMCAo in mice. Our data show that focal cerebral ischemia induces a long-term regenerative response in both brain hemispheres.
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Collinson, Simon L., Clare E. Mackay, Anthony C. James, Digby J. Quested, Tania Phillips, Neil Roberts, and Timothy J. Crow. "Brain volume, asymmetry and intellectual impairment in relation to sex in early-onset schizophrenia." British Journal of Psychiatry 183, no. 2 (August 2003): 114–20. http://dx.doi.org/10.1192/bjp.183.2.114.
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BackgroundAccumulating evidence suggests that early-onset schizophrenia arises from a disturbance in the normal trajectory of cerebral development.AimsTo investigate brain structure, asymmetry and IQ in early-onset schizophrenia.MethodVolumes of left and right cerebral hemispheres and IQ were assessed in 33 participants with early-onset DSM – IV schizophrenia and 30 members of a matched, normal control group.ResultsTotal brain volume was significantly smaller in the group with early-onset disease (‘cases’) relative to the control group (4.5%), especially for the left hemisphere in males (6.0%). A significant sex x diagnosis interaction in hemisphere asymmetry revealed that the female cases group had significantly reduced rightward asymmetry relative to the female control group and that the male cases tended to have reduced leftward asymmetry relative to the male control group. Decreased left hemisphere volume in males and decreased rightward hemispheric asymmetry in females correlated with reduced IQ.ConclusionsSexually dimorphic alterations in asymmetry correlate with degree of intellectual impairment in early-onset schizophrenia.
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Сяська, Інна. "PSYCHOLOGICAL AND PEDAGOGICAL APPROACHES TO THE LEARNING ACTIVITIES OF PUPILS WITH DIFFERENT LATERALISATION OF THE CEREBRAL HEMISPHERES." Педагогічна наука і освіта ХХІ століття, no. 2 (May 1, 2024): 49–60. http://dx.doi.org/10.35619/pse.vi2.24.
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The study of the functional asymmetry of the cerebral hemispheres is an important problem of modern science. Teaching that takes into account functional asymmetry can be more effective and contribute to the development of the child’s full potential, including students with special educational needs. It has been proven that school teaching methods are usually focused on the development of the left hemisphere. This is due to the fact that language is the main means of learning at school. In the process of learning, the functional asymmetry increases: the left hemisphere specialises in symbolic operations, and the right hemisphere in figurative ones. However, teaching left- and right-brained students should not be the same. The predominance of left or right brain activity determines the type of thinking a person has, their character, temperament, memory, hand dominance and other psychophysiological features that must be taken into account for effective teaching. To study the peculiarities of the distribution of functional asymmetry of the brain, we selected 14-15 aged students, in which the process of lateralisation is considered to be completed. The results of the study of the coefficient of functional asymmetry of the brain and the type of temperament of 9th grade students of the experimental and control groups are presented. The obtained results correspond to the average world indicators. General recommendations for improving the academic achievements of adolescents with different lateralisation of the hemispheres, taking into account their individual characteristics, in particular the dominant type of temperament. The psychological and pedagogical approaches to the effective implementation of the educational process for right- and left-hemispheric students and ambidextrous students are proposed, which contain methodological recommendations for the selection of forms, methods and means of teaching students, taking into account their functional asymmetry of the hemispheres.
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Coucha, Maha, Weiguo Li, Maribeth H. Johnson, Susan C. Fagan, and Adviye Ergul. "Protein nitration impairs the myogenic tone of rat middle cerebral arteries in both ischemic and nonischemic hemispheres after ischemic stroke." American Journal of Physiology-Heart and Circulatory Physiology 305, no. 12 (December 15, 2013): H1726—H1735. http://dx.doi.org/10.1152/ajpheart.00535.2013.
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The myogenic response is crucial for maintaining vascular resistance to achieve constant perfusion during pressure fluctuations. Reduced cerebral blood flow has been reported in ischemic and nonischemic hemispheres after stroke. Ischemia-reperfusion injury and the resulting oxidative stress impair myogenic responses in the ischemic hemisphere. Yet, the mechanism by which ischemia-reperfusion affects the nonischemic side is still undetermined. The goal of the present study was to determine the effect of ischemia-reperfusion injury on the myogenic reactivity of cerebral vessels from both hemispheres and whether protein nitration due to excess peroxynitrite production is the underlying mechanism of loss of tone. Male Wistar rats were subjected to sham operation or 30-min middle cerebral artery occlusion/45-min reperfusion. Rats were administered saline, the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III), or the nitration inhibitor epicatechin at reperfusion. Middle cerebral arteries isolated from another set of control rats were exposed to ex vivo oxygen-glucose deprivation with and without glycoprotein 91 tat (NADPH oxidase inhibitor) or Nω-nitro-l-arginine methyl ester. Myogenic tone and nitrotyrosine levels were determined. Ischemia-reperfusion injury impaired the myogenic tone of vessels in both hemispheres compared with the sham group ( P < 0.001). Vessels exposed to ex vivo oxygen-glucose deprivation experienced a similar loss of myogenic tone. Inhibition of peroxynitrite parent radicals significantly improved the myogenic tone. Peroxynitrite scavenging or inhibition of nitration improved the myogenic tone of vessels from ischemic ( P < 0.001 and P < 0.05, respectively) and nonischemic ( P < 0.01 and P < 0.05, respectively) hemispheres. Nitration was significantly increased in both hemispheres versus the sham group and was normalized with epicatechin treatment. In conclusion, ischemia-reperfusion injury impairs vessel reactivity in both hemispheres via nitration. We suggest that sham operation rather than the nonischemic side should be used as a control in preclinical stroke studies.
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Bahire, Ksenija Lūcija, Reinis Maļuhins, Fiona Bello, Jolanta Upīte, Aleksandrs Makarovs, and Baiba Jansone. "Long-Term Region-Specific Mitochondrial Functionality Changes in Both Cerebral Hemispheres after fMCAo Model of Ischemic Stroke." Antioxidants 13, no. 4 (March 29, 2024): 416. http://dx.doi.org/10.3390/antiox13040416.
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Cerebral ischemia/reperfusion (I/R) refers to a secondary brain injury that results in mitochondrial dysfunction of variable extent, leading to neuronal cell damage. The impact of this process has mainly been studied in the short term, from the early hours up to one week after blood flow reperfusion, and in the ischemic hemisphere only. The focus of this study was to assess the long-term impacts of I/R on mitochondrial functionality using high-resolution fluorespirometry to evaluate state-dependent activities in both ischemic (ipsilateral) and non-ischemic (contralateral) hemispheres of male mice 60, 90, 120, and 180 days after I/R caused by 60-min-long filament-induced middle cerebral artery occlusion (fMCAo). Our results indicate that in cortical tissues, succinate-supported oxygen flux (Complex I&II OXPHOS state) and H2O2 production (Complex II LEAK state) were significantly decreased in the fMCAo (stroke) group ipsilateral hemisphere compared to measurements in the contralateral hemisphere 60 and 90 days after stroke. In hippocampal tissues, during the Complex I&II ET state, mitochondrial respiration was generally lower in the ipsilateral compared to the contralateral hemisphere 90 days following stroke. An aging-dependent impact on mitochondria oxygen consumption following I/R injury was observed 180 days after surgery, wherein Complex I&II activities were lowest in both hemispheres. The obtained results highlight the importance of long-term studies in the field of ischemic stroke, particularly when evaluating mitochondrial bioenergetics in specific brain regions within and between separately affected cerebral hemispheres.
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Jordan, Timothy R., Michelle Redwood, and Geoffrey R. Patching. "Effects of Form Familiarity on Perception of Words, Pseudowords, and Nonwords in the Two Cerebral Hemispheres." Journal of Cognitive Neuroscience 15, no. 4 (May 1, 2003): 537–48. http://dx.doi.org/10.1162/089892903321662921.
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Previous investigations of hemispheric processes of word perception provide a mixed picture of the sensitivity of each hemisphere to the familiarity of the visual form of lateralized displays. We investigated this issue by presenting words, pseudowords, and nonwords briefly to either the left (LH) or right (RH) hemisphere in lowercase, uppercase, and a matched, unfamiliar mixed-case form, and used an eye tracker to ensure central fixation and the Reicher–Wheeler task to suppress influences of stimulus asymmetry. Familiarity of form exerted a substantial effect on perception. In particular, perception of LH and RH displays of words, pseudowords, and nonwords was least accurate for mixed case, intermediate for upper case, and most accurate for lowercase. However, form had no effect on the LH advantage observed for words, pseudowords, and nonwords, indicating that form affected processing in both hemispheres to a similar extent. Moreover, LH and RH displays both showed that mixed case disrupted performance most for words, and more for pseudowords than for nonwords, indicating the sensitivity to form shown by each hemisphere reflected more than a general perceptual process. Implications for the role of form familiarity in hemispheric processing of words are discussed.
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Friedman, E. H., and K. J. Meador. "Cerebral hemispheres and the heart." Neurology 41, no. 12 (December 1, 1991): 2015. http://dx.doi.org/10.1212/wnl.41.12.2015-a.
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Meador, K. J. "Cerebral hemispheres and the heart." Neurology 41, no. 12 (December 1, 1991): 2015. http://dx.doi.org/10.1212/wnl.41.12.2015-b.
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Hiscock, Merrill, and Marcel Kinsbourne. "Specialization of the Cerebral Hemispheres." Journal of Learning Disabilities 20, no. 3 (March 1987): 130–43. http://dx.doi.org/10.1177/002221948702000301.
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Steckler, Conor M., J. Kiley Hamlin, Michael B. Miller, Danielle King, and Alan Kingstone. "Moral judgement by the disconnected left and right cerebral hemispheres: a split-brain investigation." Royal Society Open Science 4, no. 7 (July 2017): 170172. http://dx.doi.org/10.1098/rsos.170172.
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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.
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Panerai, Ronney B., Michelle Moody, Penelope J. Eames, and John F. Potter. "Dynamic cerebral autoregulation during brain activation paradigms." American Journal of Physiology-Heart and Circulatory Physiology 289, no. 3 (September 2005): H1202—H1208. http://dx.doi.org/10.1152/ajpheart.00115.2005.
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Dynamic cerebral autoregulation (CA) describes the transient response of cerebral blood flow (CBF) to rapid changes in arterial blood pressure (ABP). We tested the hypothesis that the efficiency of dynamic CA is increased by brain activation paradigms designed to induce hemispheric lateralization. CBF velocity [CBFV; bilateral, middle cerebral artery (MCA)], ABP, ECG, and end-tidal Pco2 were continuously recorded in 14 right-handed healthy subjects (21–43 yr of age), in the seated position, at rest and during 10 repeated presentations (30 s on-off) of a word generation test and a constructional puzzle. Nonstationarities were not found during rest or activation. Transfer function analysis of the ABP-CBFV (i.e., input-output) relation was performed for the 10 separate 51.2-s segments of data during activation and compared with baseline data. During activation, the coherence function below 0.05 Hz was significantly increased for the right MCA recordings for the puzzle tasks compared with baseline values (0.36 ± 0.16 vs. 0.26 ± 0.13, P < 0.05) and for the left MCA recordings for the word paradigm (0.48 ± 0.23 vs. 0.29 ± 0.16, P < 0.05). In the same frequency range, significant increases in gain were observed during the puzzle paradigm for the right (0.69 ± 0.37 vs. 0.46 ± 0.32 cm·s−1·mmHg−1, P < 0.05) and left (0.61 ± 0.29 vs. 0.45 ± 0.24 cm·s−1·mmHg−1, P < 0.05) hemispheres and during the word tasks for the left hemisphere (0.66 ± 0.31 vs. 0.39 ± 0.15 cm·s−1·mmHg−1, P < 0.01). Significant reductions in phase were observed during activation with the puzzle task for the right (−0.04 ± 1.01 vs. 0.80 ± 0.86 rad, P < 0.01) and left (0.11 ± 0.81 vs. 0.57 ± 0.51 rad, P < 0.05) hemispheres and with the word paradigm for the right hemisphere (0.05 ± 0.87 vs. 0.64 ± 0.59 rad, P < 0.05). Brain activation also led to changes in the temporal pattern of the CBFV step response. We conclude that transfer function analysis suggests important changes in dynamic CA during mental activation tasks.
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Kuznetsova, S., and N. Skachkova. "EFFECT OF REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION ON THE CEREBRAL HEMODYNAMIC IN STROKE PATIENTS." National Journal of Neurology 1, no. 11 (July 30, 2017): 61–66. http://dx.doi.org/10.61788/njn.v1i17.09.
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The article presents the analysis of the impact of a course of combined repetitive transcranial and peripheral magnetic stimulation on the cerebral hemodynamic in 74 patients with ischemic stroke. Patients received repetitive transcranial and peripheral magnetic stimulation (study group) or placebo repetitive transcranial and peripheral magnetic stimulation (placebo group) for 10 days twice a day against the background of conventional drug therapy. It was found that in study group versus placebo group observed a more pronounced improvement of cerebral blood flow. Hemodynamic portraits of repetitive transcranial and peripheral magnetic stimulation in patients with stroke have hemispheric features. Repetitive transcranial and peripheral magnetic stimulation increases linear velocity of cerebral blood flow in patients with right-side stroke in separate vessels of the affected hemisphere. In patients with left-side stroke repetitive transcranial and peripheral magnetic stimulation promotes linear velocity of cerebral blood flow in vessels both affected and intact hemispheres. The positive effect of repetitive transcranial and peripheral magnetic stimulation on the cerebral hemodynamic in ischemic stroke patients justifies the inclusion of this method in a comprehensive system of rehabilitation of these patients.
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Katz, Albert N. "The Relationships between Creativity and Cerebral Hemisphericity for Creative Architects, Scientists, and Mathematicians." Empirical Studies of the Arts 4, no. 2 (July 1986): 97–108. http://dx.doi.org/10.2190/6nhb-pev0-25kp-ukec.
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The relationship between creativity and the specialized cognitive functions supported by each of the cerebral hemispheres (hemisphericity), was examined on archival data available for creative architects, scientists, and mathematicians. Hemisphericity was estimated by the A/P ratio, in which A represents performance on the Street Gestalt Completion test, a marker test of right hemipsheric processes and P represents performance on a marker test of left hemispheric functioning, the Similarities subtest of the WAIS. Creativity was indexed by objective indices (such as the number of patents earned by each scientist), subjective measures (such as peer evaluations of creativity) and by psychometric instruments that purport to measure creativity. Performance on a test of general intelligence was also examined. The data indicates that hemisphericity is related to some indices of creative performance (especially the objective measures) but not to the index of general intelligence. Moreover, the direction of the relationships were different for the creative architects than for the creative scientists and mathematicians. These data were taken as support for the proposition that creativity depends on the cognitive functions supported by both hemispheres: different professions demand a specific cognitive mode for efficient performance; creative performance is reflected in those who can also access and are efficient in using the cognitive mode supported by the complementary cerebral hemisphere.
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PREDA, Vasile Radu. "Cerebral Hemispheric Dominance and Lateralization. Examination methods and procedures." Revista Română de Terapia Tulburărilor de Limbaj şi Comunicare VII, no. 2 (October 31, 2021): 67–84. http://dx.doi.org/10.26744/rrttlc.2021.7.2.07.
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On the basis of electrophysiological and neuropsychological investigations the existence of cerebral hemispheric dominance has been established. Thus, a certain psycho-behavioural function may not be equally governed by either the left or the right hemisphere, a tendency towards lateralization coming into play (Sperri, 1974; Arseni, Golu, Dănăilă, 1983; Funnell, Carballis, Gazzanga, 2000). The functional asymmetry of the analysers is encountered both at the peripheral level, through the sensory-motor lateralization of paired receptors, and at the cortical level, through the asymmetrical functioning of the cerebral hemispheres. Consequently, tests for hemispheric dominance, as well as tests for lateralization must, respectively, be employed. When examining cerebral hemispheric dominance and lateralization, the characteristics of the organs under investigation are taken into account, and so is the age of the subjects. The examination of functional asymmetry in the case of analyzers with paired receptors has relied on an impressive number of trials, procedures, tests and questionnaires on lateralization, all suitable for the subjects’ age and for the psycho-physiological characteristics of the respective couple of paired organs. The combined use of lateralization tests specifically adapted for all paired organs (hand, eye, is essential in order to establish the degree of lateralization homogeneity. The examinations and the calculation of the laterality index are to be done periodically, the results being recorded in a chart that reflects the evolution of lateralization as a result of engaging the child in various activities meant for a specific type of lateralization.
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Sholihah, Rizki Amalia. "Language and Brain: Neurological Aspects in Language Acquisition." MUHARRIK: Jurnal Dakwah dan Sosial 5, no. 1 (August 12, 2022): 220–30. http://dx.doi.org/10.37680/muharrik.v5i1.1069.
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The human nervous system consists of two parts, namely the spine and the brain. The brain itself consists of the brain stem and cerebral cortex, consisting of the right and left hemispheres. Each hemisphere is divided into four lobes: the frontal lobe, occipital lobe, temporal lobe, and parietal lobe, where each lobe has its function—the brain experiences both growth regarding its parts and mass or weight. The left and right hemispheres have their respective roles or functions, leading to a tendency to use hemispheres. The left hemisphere is more dominantly responsible for language, logical and analytical matters. At the same time, the right hemisphere is more intuitive and imaginative. Concerning producing speech, the brain has a part called the Broca region. Then there is the Wernicke area which is responsible for speech comprehension. These two regions will work together for language processing in the brain. Besides, there is a system related to the workings of emotions in humans called the limbic system in the brain.
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Robertson, Lynn C., and Richard Ivry. "Hemispheric Asymmetries." Current Directions in Psychological Science 9, no. 2 (April 2000): 59–63. http://dx.doi.org/10.1111/1467-8721.00061.
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A computational theory of hemispheric asymmetries in perception (double filtering by frequency) is described. Its central tenet is that the cerebral hemispheres first perform symmetric filtering of visual and auditory information. Functional hemispheric asymmetry arises from a second filtering stage (containing filters skewed in different directions in the two hemispheres). The first stage selects a range of task-relevant spatial or auditory frequencies from the absolute values. This range is passed to the asymmetric filters. In this way, the hemispheric difference becomes one of relative rather than absolute information. Behavioral deficits due to unilateral lesions in neurological patients and neuroimaging and electrophysiological measures in normal subjects implicate posterior cortex in these hemispheric differences.
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Persinger, M. A. "Vectorial Cerebral Hemisphericity as Differential Sources for the Sensed Presence, Mystical Experiences and Religious Conversions." Perceptual and Motor Skills 76, no. 3 (June 1993): 915–30. http://dx.doi.org/10.2466/pms.1993.76.3.915.
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Multiple variants of the sensed presence often precede mystical and religious experiences that are frequently followed by sudden, permanent changes in self-concept. The model of vectorial hemisphericity assumes that the relative metabolic activity of synaptic patterns between the cerebral hemispheres at the time of transient interhemispheric intercalation determines the affect, content, and type of experience. Depending upon the relative activity of the two hemispheres, intrusions of the right hemispheric equivalent of the left hemispheric (and linguistic) sense of self generate experiential phenomena that include “evil entities,” gods, out-of-body experiences, and alterations in space-time. Conditions that facilitate interhemispheric intercalation and the generation of these experiences are discussed.
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Schweitzer, Laurence R. "Binary-Choice Decision Time Depends upon Cerebral Hemisphere and Nature of Task." Perceptual and Motor Skills 73, no. 1 (August 1991): 147–61. http://dx.doi.org/10.2466/pms.1991.73.1.147.
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Binary-choice paradigms are classificatory problems of basic importance to the understanding of elementary decision processes. Generally when subjects decide if two visual stimuli are identical or differ by as little as one element, the decision of “Different” takes longer. This finding is unexpected as decisions of “Different” should not require an exhaustive matching of elements. Using stimulus presentation to the right and left cerebral hemispheres, the right hemisphere initiated fast selections of “Same” for figural material and alone was responsible for the “Same”/ “Different” response differential. Exp. 1 ( n = 22) gave no differences for same-different, unilateral-bilateral stimulation, and left-right hemispheres. Exp. 2, using word meaning as the binary-choice task, also showed faster decisions for “Same” but a different left-hemisphere-dependent strategy. The nature of information processing in relation to binary-choice tasks is discussed and the utility of bihemispheric paradigms is demonstrated.
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Almeida, Lygia, and Rui Campos. "Systematization, description and territory of the caudal cerebral artery of the brain in broad-snouted Caiman (Caiman latirostris)." Pesquisa Veterinária Brasileira 31, no. 9 (September 2011): 817–22. http://dx.doi.org/10.1590/s0100-736x2011000900015.
Full textAbstract:
Thirty heads with the neck segment of Caiman latirostris were used. The animals were provided from a creation center called Mister Caiman, under the authorization of the Brazilian Institute of Environment and Renewable Natural Resources (Ibama). Animals were sacrificed according to the slaughtering routine of the abattoir, and the heads were sectioned at the level of the third cervical vertebra. The arterial system was washed with cold saline solution, with drainage through jugular veins. Subsequently, the system was filled with red colored latex injection. Pieces were than fixed in 20% formaldehyde, for seven days. The brains were removed, with a spinal cord segment, the duramater removed and the arteries dissected. At the level of the hypophysis, the internal carotid artery gave off a rostral branch, and a short caudal branch, continuing, naturally, as the caudal cerebral artery. This artery projected laterodorsalwards and, as it overpassed the optic tract, gave off its I (the first) central branch. Penetrated in the cerebral transverse fissure, emitting the diencephalic artery and next its II (second) central branch. Still inside the fissure, originated occipital hemispheric branches and a pineal branch. Emerged from the cerebral transverse fissure, over the occipital pole of the cerebral hemisphere. Projected rostralwards, sagital to the cerebral longitudinal fissure, as interhemispheric artery. This artery gave off medial and convex hemispheric branches to the respective surfaces of the cerebral hemispheres, anastomosed with its contralateral homologous, forming the common ethmoidal artery. This artery entered the fissure between the olfactory peduncles, emerging ventrally and dividing into ethmoidal arteries, right and left, which progressed towards the nasal cavities, vascularizing them. The territory of the caudal cerebral artery included the most caudal area of the base of the cerebral hemisphere, its convex surface, the olfactory peduncles and bulbs, the choroid plexuses and the diencephalus with its parietal organs.
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Grimshaw, Gina M. "Integration and Interference in the Cerebral Hemispheres: Relations with Hemispheric Specialization." Brain and Cognition 36, no. 2 (March 1998): 108–27. http://dx.doi.org/10.1006/brcg.1997.0949.
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Kaya, Kutlu, Alexander I. Zavriyev, Felipe Orihuela-Espina, Mirela V. Simon, Glenn M. LaMuraglia, Eric T. Pierce, Maria Angela Franceschini, and John Sunwoo. "Intraoperative Cerebral Hemodynamic Monitoring during Carotid Endarterectomy via Diffuse Correlation Spectroscopy and Near-Infrared Spectroscopy." Brain Sciences 12, no. 8 (August 2, 2022): 1025. http://dx.doi.org/10.3390/brainsci12081025.
Full textAbstract:
Objective: This pilot study aims to show the feasibility of noninvasive and real-time cerebral hemodynamic monitoring during carotid endarterectomy (CEA) via diffuse correlation spectroscopy (DCS) and near-infrared spectroscopy (NIRS). Methods: Cerebral blood flow index (CBFi) was measured unilaterally in seven patients and bilaterally in seventeen patients via DCS. In fourteen patients, hemoglobin oxygenation changes were measured bilaterally and simultaneously via NIRS. Cerebral autoregulation (CAR) and cerebrovascular resistance (CVR) were estimated using CBFi and arterial blood pressure data. Further, compensatory responses to the ipsilateral hemisphere were investigated at different contralateral stenosis levels. Results: Clamping of carotid arteries caused a sharp increase of CVR (~70%) and a marked decrease of ipsilateral CBFi (57%). From the initial drop, we observed partial recovery in CBFi, an increase of blood volume, and a reduction in CVR in the ipsilateral hemisphere. There were no significant changes in compensatory responses between different contralateral stenosis levels as CAR was intact in both hemispheres throughout the CEA phase. A comparison between hemispheric CBFi showed lower ipsilateral levels during the CEA and post-CEA phases (p < 0.001, 0.03). Conclusion: DCS alone or combined with NIRS is a useful monitoring technique for real-time assessment of cerebral hemodynamic changes and allows individualized strategies to improve cerebral perfusion during CEA by identifying different hemodynamic metrics.
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Collin, C., and F. Lolas. "Hemispheric contribution to vertex augmentation/reduction of the auditory evoked potential." Arquivos de Neuro-Psiquiatria 43, no. 4 (December 1985): 347–54. http://dx.doi.org/10.1590/s0004-282x1985000400002.
Full textAbstract:
Starting off from the notion that the cerebral hemispheres differ in their processing mode, this paper reports on stimulus intensity modulation of auditory evoked potentials recorded from hemispheric leads (C3 and C4 referenced to ipsilateral mastoid processes) in a sample of 40 male Ss between 18 to 40 years of age. The experimental set up involved the recording of series of 100 trials to binaural clicks of 63.5, 74.6 and 85dB AL. Ss who were augmenters at the vertex showed positive Amplitude-Intensity function slopes over the left hemisphere; when Ss were Reducers at the vertex, the slopes were negative on the right hemisphere. These results are interpreted in terms of attention deployment or allocation to one or the other hemispheric processing mode. This might constitute a trait-like enduring subject characteristic whose relation to traditional psychometric variables needs further exploration. The modality especificity of this phenomenon is also discussed.