Science.gov

Sample records for affected cerebral hemisphere

  1. Hemispheric specialization in affective responses, cerebral dominance for language, and handedness: Lateralization of emotion, language, and dexterity.

    PubMed

    Costanzo, Elsa Yolanda; Villarreal, Mirta; Drucaroff, Lucas Javier; Ortiz-Villafañe, Manuel; Castro, Mariana Nair; Goldschmidt, Micaela; Wainsztein, Agustina Edith; Ladrón-de-Guevara, María Soledad; Romero, Carlos; Brusco, Luis Ignacio; Camprodon, Joan A; Nemeroff, Charles; Guinjoan, Salvador Martín

    2015-07-15

    Hemispheric specialization in affective responses has received little attention in the literature. This is a fundamental variable to understand circuit dynamics of networks subserving emotion. In this study we put to test a modified "valence" hypothesis of emotion processing, considering that sadness and happiness are processed by each hemisphere in relation to dominance for language and handedness. Mood induction and language activation during functional magnetic resonance imaging (fMRI) were used in 20 right-handed and 20 nonright-handed subjects, focusing on interconnected regions known to play critical roles in affective responses: subgenual cingulate cortex, amygdala, and anterior insular cortex. We observed a consistent relationship between lateralization of affective processing, motor dexterity, and language in individuals with clear right-handedness. Sadness induces a greater activation of right-hemisphere cortical structures in right-handed, left-dominant individuals, which is not evident in nonright-handed subjects who show no consistent hemispheric dominance for language. In anterior insula, right-handed individuals displayed reciprocal activation of either hemisphere depending upon mood valence, whereas amygdala activation was predominantly left-sided regardless of mood valence. Nonright-handed individuals exhibited less consistent brain lateralization of affective processing regardless of language and motor dexterity lateralization. In contrast with traditional views on emotion processing lateralization, hemispheric specialization in affective responses is not a unitary process but is specific to the brain structure being activated.

  2. Civilisations of the Left Cerebral Hemisphere?

    ERIC Educational Resources Information Center

    Racle, Gabriel L.

    Research conducted by Tadanobu Tsunoda on auditory and visual sensation, designed to test and understand the functions of the cerebral hemispheres, is discussed. Tsunoda discovered that the Japanese responses to sounds by the left and the right sides of the brain are very different from the responses obtained from people from other countries. His…

  3. Rat model of focal cerebral ischemia in the dominant hemisphere

    PubMed Central

    Zhang, Hua; Shen, Yan; Wang, Wei; Gao, Huanmin

    2015-01-01

    In the human brain, the dominant hemisphere is more complex than the non-dominant hemisphere. Hence, cerebral ischemia of the dominant hemisphere often leads to serious consequences. This study aims to establish a rodent model of focal cerebral ischemia in the dominant hemisphere. The quadruped feeding test was used to screen 70 male Sprague Dawley rats. From this test, 48 rats with right paw preference were selected and randomly assigned numbers. Half were assigned to the dominant hemisphere ischemia (DHI) group, and the other half were assigned to the non-dominant hemisphere ischemia (NDHI) group. The middle cerebral artery was occluded 2 h before reperfusion. Neurological functions were tested. TTC and HE staining were performed. The volume of cerebral infarction was calculated. Rats in the DHI group had significantly worse neurological scores than rats in the NDHI group (P < 0.05). TTC staining indicated ischemia had more severe consequences in the dominant hemisphere than in the non-dominant hemisphere. The dominant hippocampus indicated severe neuronal loss and disorderly cellular arrangement. The volume of cerebral infarction was also greater in the DHI group compared to the NDHI group (P < 0.05). Compared to MCA occlusion in the non-dominant hemisphere, MCA occlusion in the dominant hemisphere caused greater impairment in neurological functions. The proposed rodent model is reliable and has high levels of reproducibility. Therefore, his model can be reliably for investigating the mechanism of focal cerebral ischemia in the dominant hemisphere of human brains. PMID:25785023

  4. Mediated priming in the cerebral hemispheres.

    PubMed

    Livesay, Kay; Burgess, Curt

    2003-11-01

    The present experiment investigates hemispheric differences in mediated priming. Theories of lexical representation have argued for an asymmetrical coding between the right and left hemispheres ([Beeman, 1998]), claiming that the right hemisphere is more diffusely represented compared to the left hemisphere. Thus, the right hemisphere activates a larger semantic field compared to the left hemisphere. Mediated (two-step) priming is an ideal task to examine this representational claim, because of the distant nature of the prime-target pairs. Results showed no difference in the magnitude of priming (both mediated and direct) between the right and left hemispheres. These results suggest that the lexical representation of the two hemispheres is equivalent, not asymmetrical as Beeman suggests.

  5. Specialization of the Cerebral Hemispheres: Implications for Learning.

    ERIC Educational Resources Information Center

    Hiscock, Merrill; Kinsbourne, Marcel

    1987-01-01

    Among conclusions of this review of findings regarding contemporary neuropsychology and cerebral hemisphere specialization as related to learning disabilities are: (1) differential specialization occurs very early; (2) anomalous hemispheric specialization is not necessarily associated with cognitive deficit; and (3) left- and right-hemisphere…

  6. Differential diagnosis of cerebral hemispheric pathology: multimodal approach.

    PubMed

    Moritani, T; Smoker, W R K; Lee, H K; Sato, Y

    2011-06-01

    This article gives a comprehensive review and illustrations of the imaging features of various pathological conditions and clinical syndromes associated with cerebral hemispheric involvement. The various conditions are described and defined to provide a basis for the differential diagnostics. The hypotheses relating to the pathology of the various syndromes are discussed with special emphasis on excitotoxic mechanisms for explaining the subsequent cerebral hemiatrophy.

  7. Left hemisphere and male sex dominance of cerebral hemiatrophy (Dyke-Davidoff-Masson Syndrome).

    PubMed

    Unal, Ozkan; Tombul, Temel; Cirak, Bayram; Anlar, Omer; Incesu, Lütfi; Kayan, Mustafa

    2004-01-01

    Although radiological findings of cerebral hemiatrophy (Dyke-Davidoff-Masson Syndrome) are well known, there is no systematic study about the gender and the affected side in this syndrome. Brain images in 26 patients (mean aged 11) with cerebral hemiatrophy were retrospectively reviewed. Nineteen patients (73.5%) were male and seven patients (26.5%) were female. Left hemisphere involvement was seen in 18 patients (69.2%) and right hemisphere involvement was seen in eight patients (30.8%). We conclude that male gender and left side involvement are frequent in cerebral hemiatrophy disease.

  8. Interaction of cerebral hemispheres and artistic thinking

    NASA Astrophysics Data System (ADS)

    Nikolaenko, Nikolay N.

    1998-07-01

    Study of drawings by patients with local lesions of the right or left hemisphere allows to understand how artistic thinking is supported by brain structures. The role of the right hemisphere is significant at the early stage of creative process. The right hemisphere is a generator of nonverbal visuo-spatial thinking. It operates with blurred nonverbal images and arrange them in a visual space. With the help of iconic signs the right hemisphere reflects the world and creates perceptive visual standards which are stored in the long-term right hemisphere memory. The image, which appeared in the `inner' space, should be transferred into a principally different language, i.e. a left hemispheric sign language. This language operates with a number of discrete units, logical succession and learned grammar rules. This process can be explained by activation (information) transfer from the right hemisphere to the left one. Thus, natural and spontaneous creative process, which is finished by a conscious effort, can be understood as an activation impulse transfer from the right hemisphere to the left one and back.

  9. Right hemisphere involvement in depression: toward a neuropsychological theory of negative affective experiences.

    PubMed

    Otto, M W; Yeo, R A; Dougher, M J

    1987-10-01

    Several lines of inquiry provide converging evidence for a critical role for the right cerebral hemisphere in negative affective experiences. This research includes the assessment of affective consequences of both focal cerebral lesions and pharmacological inactivation of one or the other hemisphere, as well as experimental and physiological techniques assessing differential hemispheric activation. The specific nature of right hemispheric involvement is conceptualized as a tendency to become activated by aversive experiences, and once activated, to process stimuli in a manner consistent with the right hemisphere's more negative affective tone. A theory of right hemisphere involvement in depressive affect is presented in detail and its relevance to clinical phenomena, e.g., the co-occurrence of depression and pain, and sex differences in depression, is examined, as is congruence with cognitive theories of depression.

  10. Meaning Apprehension in the Cerebral Hemispheres

    ERIC Educational Resources Information Center

    Kandhadai, Padmapriya A.

    2009-01-01

    When we hear a word, it is remarkable how we store, activate and rapidly retrieve a vast amount of relevant information within a few hundred milliseconds. This thesis examines how meaning is processed in parallel--but with critical differences--between the two hemispheres of the brain. Event-related brain potentials (ERP) were used to examine…

  11. Schizophrenia, the sense of 'self' and the right cerebral hemisphere.

    PubMed

    Hecht, David

    2010-01-01

    Schizophrenia is described in phenomenological theory as an illness with various degrees of 'self disintegration' and/or 'disembodiment' experiences. Cognitive neuroscience and neurology had identified specific brain structures, all in the right cerebral hemisphere, that are crucial for the generation of a normal 'sense of self' and self-corporeal-awareness. Behavioral and neuroanatomical evidence also suggest various deficits in the right hemisphere of schizophrenics. A hypothesis is put forth here for a strong linkage and correlation between the specific brain constructs involved in self/corporeal-awareness and the schizophrenic symptoms manifesting the disintegration of the 'self'.

  12. Testing the Language of German Cerebral Palsy Patients with Right Hemispheric Language Organization after Early Left Hemispheric Damage

    ERIC Educational Resources Information Center

    Schwilling, Eleonore; Krageloh-Mann, Ingeborg; Konietzko, Andreas; Winkler, Susanne; Lidzba, Karen

    2012-01-01

    Language functions are generally represented in the left cerebral hemisphere. After early (prenatally acquired or perinatally acquired) left hemispheric brain damage language functions may be salvaged by reorganization into the right hemisphere. This is different from brain lesions acquired in adulthood which normally lead to aphasia. Right…

  13. Visual attention modulates the asymmetric influence of each cerebral hemisphere on spatial perception

    PubMed Central

    Wang, Meijian; Wang, Xiuhai; Xue, Lingyan; Huang, Dan; Chen, Yao

    2016-01-01

    Although the allocation of brain functions across the two cerebral hemispheres has aroused public interest over the past century, asymmetric interhemispheric cooperation under attentional modulation has been scarcely investigated. An example of interhemispheric cooperation is visual spatial perception. During this process, visual information from each hemisphere is integrated because each half of the visual field predominantly projects to the contralateral visual cortex. Both egocentric and allocentric coordinates can be employed for visual spatial representation, but they activate different areas in primate cerebral hemispheres. Recent studies have determined that egocentric representation affects the reaction time of allocentric perception; furthermore, this influence is asymmetric between the two visual hemifields. The egocentric-allocentric incompatibility effect and its asymmetry between the two hemispheres can produce this phenomenon. Using an allocentric position judgment task, we found that this incompatibility effect was reduced, and its asymmetry was eliminated on an attentional task rather than a neutral task. Visual attention might activate cortical areas that process conflicting information, such as the anterior cingulate cortex, and balance the asymmetry between the two hemispheres. Attention may enhance and balance this interhemispheric cooperation because this imbalance may also be caused by the asymmetric cooperation of each hemisphere in spatial perception. PMID:26758349

  14. Effects of daily noise on fetuses and cerebral hemisphere specialization in children

    NASA Astrophysics Data System (ADS)

    Ando, Y.

    1988-12-01

    This paper first provides an overview of work by the author and colleagues on effects of noise on fetuses demonstrating growth inhibition. As a second issue, the effects of daily noise on the mental abilities of children are discussed in relation to task specification of cerebral hemispheres. Two different types of mental tasks were given to a total of 1286 children (7-10 years old) who live in a noisy area around an international airport or in a neighbouring quiet area, under conditions of no sound, jet-plane noise stimulus and music stimulus. In the quiet neighborhood, results may support a model that noise and calculation tasks are separately processed in the right and left cerebral hemisphere, respectively. Music perception and calculation are considered to be processed one after the other in the left hemisphere. In the pattern search task used as the right hemispheric task, no significant differences appeared under either stimulus sound, with the exception of a slight interference observed in the noise group. In the noisy living area, however, effects of temporary sound on mental tasks appeared to be quite different from the first-mentioned results. These facts suggest that daily noise affects the development of cerebral specialization of growing children. As little is known about effects of noise on growing children, it is recommended that international cooperation be initiated to establish the need for and conditions of healthy sound environments.

  15. Controlled semantic processes within and between the two cerebral hemispheres.

    PubMed

    Peleg, Orna; Eviatar, Zohar

    2017-01-01

    To test the separate and combined abilities of the two cerebral hemispheres to perform controlled semantic selection and integration processes, Hebrew readers saw pairs of words and had to decide whether the two words were semantically related. The first word in each pair was presented centrally. The second word was presented in the left, right, or central visual field (LVF, RVF, and CVF). We compared response latencies for related pairs in two conditions: In the ambiguous condition, the first word was a homograph (either homophonic or heterophonic) and the second word was related to either its dominant or subordinate meaning. In the unambiguous condition, homographs were replaced with unambiguous control words. Irrespective of VF or homograph type, response times for ambiguous pairs were significantly longer than for unambiguous pairs only when targets were related to the subordinate meaning of the homograph. In the left hemisphere (RVF/LH), this ambiguity effect was larger for heterophones than for homophones, whereas in the right hemisphere (LVF/RH), similar patterns were observed for both types of homographs. Finally, performance patterns in the CVF revealed the same patterns as those in the RVF/LH, and were different from those in the LVF/RH. The implications of these results are discussed.

  16. Cerebral specialization. [greater performance efficiency for certain mental abilities or processes by one cerebral hemisphere over another

    NASA Technical Reports Server (NTRS)

    Morris, Robin D.; Hopkins, William D.; Rumbaugh, Duane M.

    1991-01-01

    The concept of greater performance efficiency for certain mental abilities or processes in one cerebral hemisphere rather than the other is referred to as 'cerebral lateralization'. The experimental paradigm for lateralization research involves the study of patients with one damaged hemisphere, which prevents their performance of a certain task or function; this approach, however, presents many difficulties in extrapolating to brain function in normal patients. Attention is presently given to gender differences in lateralization, cerebral asymmetries in other species, and the evolutionary bases of hemispheric specialization.

  17. Main effects and interactions of cerebral hemispheres, gender, and age in the calculation of volumes and asymmetries of selected structures of episodic memory

    PubMed Central

    Ramirez-Carmona, Rocio; Garcia-Lazaro, Haydee Guadalupe; Dominguez-Corrales, Brenda; Aguilar-Castañeda, Erika; Roldan-Valadez, Ernesto

    2016-01-01

    Summary The aim of this study was to clarify the influence of anatomical (cerebral hemisphere) and demographic (age and gender) variables on the gray matter (GM) volumes and volumetric asymmetry indices (VAIs) of selected structures involved in episodic memory. A cross-sectional study was performed in 47 healthy volunteers. Neuropsychological evaluation revealed similar IQs across the sample. Using SPM-based software, brain segmentation, labeling and volume measurements of the hippocampus, amygdala, middle temporal gyrus and parahippocampal gyrus were performed in each cerebral hemisphere. A two-way between-groups multivariate analysis of covariance (MANCOVA) was applied to GM volumes and VAIs. The main effects of gender and cerebral hemisphere on GM volumes were significant (p < .001), while there was no significant interaction effect between gender and cerebral hemisphere. VAI measurements showed a non-significant effect of gender, but a significant influence of age (p = .015). The linear model of interactions and main effects explained 33% of the variance influencing the GM volume quantification. While cerebral hemisphere and gender were found to affect the volumes of brain structures involved in episodic memory, the calculation of VAIs was affected only by age. A comprehensive understanding of the main effects and interaction effects of cerebral hemisphere, gender and age on the volumes and asymmetries of structures related to episodic memory might help neurologists, psychiatrists, geriatricians and other neuroscientists in the study of degenerative brain diseases. PMID:28072386

  18. Main effects and interactions of cerebral hemispheres, gender, and age in the calculation of volumes and asymmetries of selected structures of episodic memory.

    PubMed

    Ramirez-Carmona, Rocio; Garcia-Lazaro, Haydee Guadalupe; Dominguez-Corrales, Brenda; Aguilar-Castañeda, Erika; Roldan-Valadez, Ernesto

    The aim of this study was to clarify the influence of anatomical (cerebral hemisphere) and demographic (age and gender) variables on the gray matter (GM) volumes and volumetric asymmetry indices (VAIs) of selected structures involved in episodic memory. A cross-sectional study was performed in 47 healthy volunteers. Neuropsychological evaluation revealed similar IQs across the sample. Using SPM-based software, brain segmentation, labeling and volume measurements of the hippocampus, amygdala, middle temporal gyrus and parahippocampal gyrus were performed in each cerebral hemisphere. A two-way between-groups multivariate analysis of covariance (MANCOVA) was applied to GM volumes and VAIs. The main effects of gender and cerebral hemisphere on GM volumes were significant (p < .001), while there was no significant interaction effect between gender and cerebral hemisphere. VAI measurements showed a nonsignificant effect of gender, but a significant influence of age (p = .015). The linear model of interactions and main effects explained 33% of the variance influencing the GM volume quantification. While cerebral hemisphere and gender were found to affect the volumes of brain structures involved in episodic memory, the calculation of VAIs was affected only by age. A comprehensive understanding of the main effects and interaction effects of cerebral hemisphere, gender and age on the volumes and asymmetries of structures related to episodic memory might help neurologists, psychiatrists, geriatricians and other neuroscientists in the study of degenerative brain diseases.

  19. Sex Differences in the Association of Cerebral Hemispheric Specialization of Spatial Function with Conservation Task Performance.

    ERIC Educational Resources Information Center

    Affleck, Glenn; Joyce, Patricia

    1979-01-01

    The association of locus of cerebral hemispheric specialization of spatial function with identity and equivalence conservation judgments was tested in a group of four- to six-year-old right-handed children (N=31). (Author/MP)

  20. Hemispheric Lateralization, Cerebral Dominance, Conjugate Saccadic Behavior and Their Use in Identifying the Creatively Gifted.

    ERIC Educational Resources Information Center

    Rekdal, C. K.

    1979-01-01

    In an effort to establish new means of locating the gifted creative productive thinker, an investigation of current brain research in the areas of hemispheric lateralization, cerebral dominance and conjugate saccadic behavior is analyzed. (Author/PHR)

  1. Hemispheric processing of memory is affected by sleep.

    PubMed

    Monaghan, Padraic; Shaw, John J; Ashworth-Lord, Anneliese; Newbury, Chloe R

    2017-04-01

    Sleep is known to affect learning and memory, but the extent to which it influences behavioural processing in the left and right hemispheres of the brain is as yet unknown. We tested two hypotheses about lateralised effects of sleep on recognition memory for words: whether sleep reactivated recent experiences of words promoting access to the long-term store in the left hemisphere (LH), and whether sleep enhanced spreading activation differentially in semantic networks in the hemispheres. In Experiment 1, participants viewed lists of semantically related words, then slept or stayed awake for 12h before being tested on seen, unseen but related, or unrelated words presented to the left or the right hemisphere. Sleep was found to promote word recognition in the LH, and to spread activation equally within semantic networks in both hemispheres. Experiment 2 ensured that the results were not due to time of day effects influencing cognitive performance.

  2. Regional brain blood flow and cerebral hemispheric oxygen consumption during acute hypoxaemia in the llama fetus

    PubMed Central

    Llanos, Aníbal J; Riquelme, Raquel A; Sanhueza, Emilia M; Herrera, Emilio; Cabello, Gertrudis; Giussani, Dino A; Parer, Julian T

    2002-01-01

    Unlike fetal animals of lowland species, the llama fetus does not increase its cerebral blood flow during an episode of acute hypoxaemia. This study tested the hypothesis that the fetal llama brain maintains cerebral hemispheric O2 consumption by increasing cerebral O2 extraction rather than decreasing cerebral oxygen utilisation during acute hypoxaemia. Six llama fetuses were surgically instrumented under general anaesthesia at 217 days of gestation (term ca 350 days) with vascular and amniotic catheters in order to carry out cardiorespiratory studies. Following a control period of 1 h, the llama fetuses underwent 3 × 20 min episodes of progressive hypoxaemia, induced by maternal inhalational hypoxia. During basal conditions and during each of the 20 min of hypoxaemia, fetal cerebral blood flow was measured with radioactive microspheres, cerebral oxygen extraction was calculated, and fetal cerebral hemispheric O2 consumption was determined by the modified Fick principle. During hypoxaemia, fetal arterial O2 tension and fetal pH decreased progressively from 24 ± 1 to 20 ± 1 Torr and from 7.36 ± 0.01 to 7.33 ± 0.01, respectively, during the first 20 min episode, to 16 ± 1 Torr and 7.25 ± 0.05 during the second 20 min episode and to 14 ± 1 Torr and 7.21 ± 0.04 during the final 20 min episode. Fetal arterial partial pressure of CO2 (Pa,CO2, 42 ± 2 Torr) remained unaltered from baseline throughout the experiment. Fetal cerebral hemispheric blood flow and cerebral hemispheric oxygen extraction were unaltered from baseline during progressive hypoxaemia. In contrast, a progressive fall in fetal cerebral hemispheric oxygen consumption occurred during the hypoxaemic challenge. In conclusion, these data do not support the hypothesis that the fetal llama brain maintains cerebral hemispheric O2 consumption by increasing cerebral hemispheric O2 extraction. Rather, the data show that in the llama fetus, a reduction in cerebral hemispheric metabolism occurs during acute

  3. Spatial and selective attention in the cerebral hemispheres in depression, mania, and schizophrenia.

    PubMed

    David, A S

    1993-11-01

    Two tachistoscopic tests examining distinct aspects of attention were administered to normal subjects and patients with depression, mania, and schizophrenia. The first examined spatial attentional bias using happy-sad chimeric faces, known to elicit a perceptual bias to the left side of space in normal right-handers provided the right cerebral hemisphere is intact. The second used a lateralized version of the Stroop task, a traditional test of selective attention. Normals showed the expected leftward perceptual bias but showed equivalent susceptibility to the Stroop effect in both visual fields. As previously demonstrated with chimeric faces viewed in free vision, depression and mania were associated with weak and strong biases respectively with schizophrenics showing no bias to either side of space. The relationship between perceptual bias, as assessed by reaction time and absolute performance and the Stroop effect, showed differences according to diagnosis. This may be interpreted as evidence for the dissociability of attentional processes as well as lateralized differences in the pattern of cerebral activation in affective disorders and schizophrenia. The independence of performance variables on these tests in the schizophrenic group points to severe neuropsychological dysfunction.

  4. Human cerebral response to animal affective vocalizations.

    PubMed

    Belin, Pascal; Fecteau, Shirley; Charest, Ian; Nicastro, Nicholas; Hauser, Marc D; Armony, Jorge L

    2008-03-07

    It is presently unknown whether our response to affective vocalizations is specific to those generated by humans or more universal, triggered by emotionally matched vocalizations generated by other species. Here, we used functional magnetic resonance imaging in normal participants to measure cerebral activity during auditory stimulation with affectively valenced animal vocalizations, some familiar (cats) and others not (rhesus monkeys). Positively versus negatively valenced vocalizations from cats and monkeys elicited different cerebral responses despite the participants' inability to differentiate the valence of these animal vocalizations by overt behavioural responses. Moreover, the comparison with human non-speech affective vocalizations revealed a common response to the valence in orbitofrontal cortex, a key component on the limbic system. These findings suggest that the neural mechanisms involved in processing human affective vocalizations may be recruited by heterospecific affective vocalizations at an unconscious level, supporting claims of shared emotional systems across species.

  5. Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic.

    PubMed

    Powers, William J; Videen, Tom O; Markham, Joanne; Walter, Vonn; Perlmutter, Joel S

    2011-05-01

    Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO(2)) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO(2), CMRglc, and other covariates as predictors of resting CBF among 23 normal humans. The univariate analysis showed that only CMRO(2) was a significant predictor of CBF. The final multivariate model contained two additional terms in addition to CMRO(2): arterial oxygen content and oxygen extraction fraction. Notably, arterial plasma glucose concentration and CMRglc were not included in the final model. Our data demonstrate that the metabolic factor controlling hemispheric CBF in the normal resting brain is CMRO(2) and that CMRglc does not make a contribution. Our findings provide evidence for compartmentalization of brain metabolism into a basal component in which CBF is coupled to oxygen metabolism and an activation component in which CBF is controlled by another mechanism.

  6. The impact of asymmetrical light input on cerebral hemispheric specialization and interhemispheric cooperation.

    PubMed

    Manns, Martina; Römling, Juliane

    2012-02-28

    Hemispheric specialization potentially provides evolutionary advantages by enhancing cognitive capacities. However, separation of function might be advantageous only with the presence of commissural systems allowing for efficient information exchange and cooperation between the hemispheres. Here we investigate hemispheric cooperation in pigeons as they possess an asymmetrically organized visual system that develops in response to biased ontogenetic light stimulation. This allows comparison of the integration capacities of lateralized (light-incubated) and non-lateralized (dark-incubated) animals. We show that pigeons integrate information learnt separately with each hemisphere when confronted with a transitive reasoning task that they cannot solve with the knowledge of one hemisphere alone. Impairments in dark-incubated birds demonstrate that this ability depends on asymmetrical embryonic light stimulation. Our study provides for the first time direct evidence that lateralized environmental experience not only induces hemispheric specialization, but also affects the efficiency of interhemispheric crosstalk. Environmental factors can influence the tight interplay between the hemispheres, which in turn determines cognitive abilities.

  7. Comparison of the two cerebral hemispheres in inhibitory processes operative during movement preparation

    PubMed Central

    Klein, Pierre-Alexandre; Duque, Julie; Labruna, Ludovica; Ivry, Richard B.

    2015-01-01

    was a global difference in CS excitability across experiments between the two hemispheres. When the intensity of stimulation was set to 115% of the resting threshold, MEPs were larger when the TMS probe was applied over the M1LEFT than over M1RIGHT. In summary, while the latter result suggests that M1LEFT is more excitable than M1RIGHT, the recruitment of preparatory inhibitory mechanisms is similar within the two cerebral hemispheres. PMID:26458519

  8. Hemispheric Brain Preference: What Are the Educational Implications?

    ERIC Educational Resources Information Center

    Fountain, Juanita Cummings; Fillmer, H. Thompson

    1987-01-01

    Investigates the relationship between hemisphere, brain preferences, and academic failure or success by studying 131 average and above average fourth and seventh grade students. Concludes that cerebral hemisphere functions do affect learning. (MM)

  9. Frequency-difference MIT imaging of cerebral haemorrhage with a hemispherical coil array: numerical modelling.

    PubMed

    Zolgharni, M; Griffiths, H; Ledger, P D

    2010-08-01

    The feasibility of detecting a cerebral haemorrhage with a hemispherical MIT coil array consisting of 56 exciter/sensor coils of 10 mm radius and operating at 1 and 10 MHz was investigated. A finite difference method combined with an anatomically realistic head model comprising 12 tissue types was used to simulate the strokes. Frequency-difference images were reconstructed from the modelled data with different levels of the added phase noise and two types of a priori boundary errors: a displacement of the head and a size scaling error. The results revealed that a noise level of 3 m degrees (standard deviation) was adequate for obtaining good visualization of a peripheral stroke (volume approximately 49 ml). The simulations further showed that the displacement error had to be within 3-4 mm and the scaling error within 3-4% so as not to cause unacceptably large artefacts on the images.

  10. Assessment of cerebral hemispheric symmetry in hatchling chickens exposed in ovo to polychlorinated biphenyl congeners.

    PubMed

    Lipsitz, L; Powell, D; Bursian, S; Tanaka, D

    1997-05-01

    Previous investigators have reported that exposure to a mixture of environmental contaminants, including polychlorinated biphenyls, results in morphologic asymmetry of the cerebral hemispheres in hatchling great blue herons (Ardea herodias) and have suggested that this asymmetry may be a useful biomarker for contamination. This study was made to determine whether exposure to PCB congeners 3,3',4,4'-tetrachlorobiphenyl (IUPAC #77) and 3,3',4,4',5-pentachlorobiphenyl (IUPAC #126) causes similar asymmetry in hatchling domestic chickens (Gallus domesticus). Eggs were injected at day 0 of incubation with either a high dose, low dose, or combination of each congener. At hatching, the chicks were perfused with 10% formalin-saline. The brains were removed, sectioned and stained with cresyl violet. Width and height measurements of each hemisphere were taken at eight locations, caudal to rostral, 400 microm apart starting at the level of the anterior commissure (CA) and ending at the lobus paraolfactorius (LPO). The absolute differences between measurements of the left and right sides were used to run a univariate split plot analysis of variance to determine if the amount of asymmetry present was associated with specific congeners or doses. Significant differences in asymmetry were found between noninjected control groups and vehicle-injected control groups (p cerebral asymmetry as a

  11. A Left Cerebral Hemisphere's Superiority in Processing Spatial-Categorical Information in a Non-Verbal Semantic Format

    ERIC Educational Resources Information Center

    Suegami, Takashi; Laeng, Bruno

    2013-01-01

    It has been shown that the left and right cerebral hemispheres (LH and RH) respectively process qualitative or "categorical" spatial relations and metric or "coordinate" spatial relations. However, categorical spatial information could be thought as divided into two types: semantically-coded and visuospatially-coded categorical information. We…

  12. Posed versus spontaneous facial expressions are modulated by opposite cerebral hemispheres.

    PubMed

    Ross, Elliott D; Pulusu, Vinay K

    2013-05-01

    Clinical research has indicated that the left face is more expressive than the right face, suggesting that modulation of facial expressions is lateralized to the right hemisphere. The findings, however, are controversial because the results explain, on average, approximately 4% of the data variance. Using high-speed videography, we sought to determine if movement-onset asymmetry was a more powerful research paradigm than terminal movement asymmetry. The results were very robust, explaining up to 70% of the data variance. Posed expressions began overwhelmingly on the right face whereas spontaneous expressions began overwhelmingly on the left face. This dichotomy was most robust for upper facial expressions. In addition, movement-onset asymmetries did not predict terminal movement asymmetries, which were not significantly lateralized. The results support recent neuroanatomic observations that upper versus lower facial movements have different forebrain motor representations and recent behavioral constructs that posed versus spontaneous facial expressions are modulated preferentially by opposite cerebral hemispheres and that spontaneous facial expressions are graded rather than non-graded movements.

  13. [Emotional behavior in schizophrenia and one-sided brain damage. Cerebral hemispheric asymmetry. Part I].

    PubMed

    Kucharska-Pietura, Katarzyna; Hunca-Bednarska, Anna

    2002-01-01

    Although, emotions play a crucial role in schizophrenia, the changes in emotional dimension in relation to brain asymmetry still remain controversial. The aim of our work was: 1) to compare the emotional behaviour between the examined groups: S--non-chronic schizophrenic patients (n = 50), CS--chronic schizophrenic patients (n = 50), N--healthy controls (n = 50), R--right brain-damaged patients (n = 30), and L--left brain-damaged patients (n = 30), 2) to assess the changes in attitude processes and in types of emotional reactions, its relation to lateralised hemisphere damage and chronicity of the schizophrenic process. All psychiatric subjects were diagnosed as paranoid schizophrenics according to DSM-IV criteria and were scored on the PANSS scale after four weeks of neuroleptic treatment. Brain-damaged patients were included if they experienced single-episode cerebrovascular accidents causing right or left hemisphere damage (confirmed in CT scan reports). The neurological patients were examined at least 3 weeks after the onset of the episode. Emotional behaviour was assessed using Observational Scale of Emotional Behaviour aimed at the evaluation of: A) attitude processes B) the emotional reactions. Our results revealed differentiated type of emotional behaviour in the examined population. Right brain-damaged patients significantly often revealed elevated mood, lack of adequacy of self-evaluation and active or negative attitude towards the environment. Left brain-damaged patients showed depressed mood, resignation, positive or seldom passive attitude to others and adequate self-evaluation. Schizophrenic patients mostly revealed indifferent mood and passive attitude to environment, their self-evaluation was rather adequate. Based on our data, the changes in emotional behaviour in schizophrenic patients might reflect frontal lobes dysfunction rather than dysfunction localised in one of cerebral hemispheres.

  14. A Gamma-Knife-Enabled Mouse Model of Cerebral Single-Hemisphere Delayed Radiation Necrosis

    PubMed Central

    Jiang, Xiaoyu; Yuan, Liya; Engelbach, John A.; Cates, Jeremy; Perez-Torres, Carlos J.; Gao, Feng; Thotala, Dinesh; Drzymala, Robert E.; Schmidt, Robert E.; Rich, Keith M.; Hallahan, Dennis E.; Ackerman, Joseph J. H.; Garbow, Joel R.

    2015-01-01

    Purpose To develop a Gamma Knife-based mouse model of late time-to-onset, cerebral radiation necrosis (RN) with serial evaluation by magnetic resonance imaging (MRI) and histology. Methods and Materials Mice were irradiated with the Leksell Gamma Knife® (GK) PerfexionTM (Elekta AB; Stockholm, Sweden) with total single-hemispheric radiation doses (TRD) of 45- to 60-Gy, delivered in one to three fractions. RN was measured using T2-weighted MR images, while confirmation of tissue damage was assessed histologically by hematoxylin & eosin, trichrome, and PTAH staining. Results MRI measurements demonstrate that TRD is a more important determinant of both time-to-onset and progression of RN than fractionation. The development of RN is significantly slower in mice irradiated with 45-Gy than 50- or 60-Gy, where RN development is similar. Irradiated mouse brains demonstrate all of the pathologic features observed clinically in patients with confirmed RN. A semi-quantitative (0 to 3) histologic grading system, capturing both the extent and severity of injury, is described and illustrated. Tissue damage, as assessed by a histologic score, correlates well with total necrotic volume measured by MRI (correlation coefficient = 0.948, with p<0.0001), and with post-irradiation time (correlation coefficient = 0.508, with p<0.0001). Conclusions Following GK irradiation, mice develop late time-to-onset cerebral RN histology mirroring clinical observations. MR imaging provides reliable quantification of the necrotic volume that correlates well with histologic score. This mouse model of RN will provide a platform for mechanism of action studies, the identification of imaging biomarkers of RN, and the development of clinical studies for improved mitigation and neuroprotection. PMID:26440791

  15. Mixing Metaphors in the Cerebral Hemispheres: What Happens When Careers Collide?

    PubMed Central

    Chettih, Selmaan; Durgin, Frank H.; Grodner, Daniel J.

    2014-01-01

    Are processes of figurative comparison and figurative categorization different? An experiment combining alternative-sense and matched-sense metaphor priming with a divided visual field assessment technique sought to isolate processes of comparison and categorization in the two cerebral hemispheres. For target metaphors presented in the RVF/LH, only matched-sense primes were facilitative. Literal primes and alternative-sense primes had no effect on comprehension time compared to the unprimed baseline. The effects of matched-sense primes were additive with the rated conventionality of the targets. For target metaphors presented to the LVF/RH, matched-sense primes were again additively facilitative. However, alternative-sense primes, though facilitative overall, seemed to eliminate the pre-existing advantages of conventional target metaphor senses in the LVF/RH in favor of metaphoric senses similar to those of the primes. These findings are consistent with tightly controlled categorical coding in the LH and coarse, and flexible, context dependent coding in the RH. PMID:22103787

  16. Word learning and the cerebral hemispheres: from serial to parallel processing of written words.

    PubMed

    Ellis, Andrew W; Ferreira, Roberto; Cathles-Hagan, Polly; Holt, Kathryn; Jarvis, Lisa; Barca, Laura

    2009-12-27

    Reading familiar words differs from reading unfamiliar non-words in two ways. First, word reading is faster and more accurate than reading of unfamiliar non-words. Second, effects of letter length are reduced for words, particularly when they are presented in the right visual field in familiar formats. Two experiments are reported in which right-handed participants read aloud non-words presented briefly in their left and right visual fields before and after training on those items. The non-words were interleaved with familiar words in the naming tests. Before training, naming was slow and error prone, with marked effects of length in both visual fields. After training, fewer errors were made, naming was faster, and the effect of length was much reduced in the right visual field compared with the left. We propose that word learning creates orthographic word forms in the mid-fusiform gyrus of the left cerebral hemisphere. Those word forms allow words to access their phonological and semantic representations on a lexical basis. But orthographic word forms also interact with more posterior letter recognition systems in the middle/inferior occipital gyri, inducing more parallel processing of right visual field words than is possible for any left visual field stimulus, or for unfamiliar non-words presented in the right visual field.

  17. Amelioration of age-dependent increase in protein carbonyls of cerebral hemispheres of mice by melatonin and ascorbic acid.

    PubMed

    Dkhar, Preeticia; Sharma, Ramesh

    2011-12-01

    Melatonin secreted by the pineal gland acts as a free radical scavenger besides its role as a hormonal signaling agent. It detoxifies a variety of free radicals and reactive oxygen intermediates including hydroxyl radical, peroxynitrite anion and singlet oxygen. Ascorbic acid (Vitamin C), a water soluble vitamin, is a naturally occurring antioxidant and cofactor in various enzymes. Protein carbonyls are formed as a consequence of the oxidative modification of proteins by reactive oxygen species. Oxidative modification alters the function of protein and is thought to play an important role in the decline of cellular functions during aging. In the present study, the effect of melatonin and ascorbic acid on age-related carbonyl content of cerebral hemispheres in mice was investigated. Protein carbonyls of cerebral hemispheres have been found to be significantly higher in 18-month-old mice as compared to 1-month old mice. Administration of a single dose of melatonin (10 mg/kg body weight) and ascorbic acid (10 mg/kg body weight) intraperitoneally for three consecutive days decreases the carbonyl content in 1- and 18-month-old mice significantly. The present study thus suggests that the formation of protein carbonyls in the cerebral hemispheres of the aging mice can be prevented by the antioxidative effects of melatonin and ascorbic acid that could in turn be beneficial in having health benefits from age-related neurodegenerative diseases.

  18. Cerebral organization in a right-handed trilingual patient with right-hemisphere speech: a positron emission tomography study.

    PubMed

    Klein, Denise; Milner, Brenda; Zatorre, Robert J; Visca, Regina; Olivier, André

    2002-01-01

    Using the method of positron emission tomography, combined with word-generation tasks, we had the opportunity to examine the cerebral representation of multiple languages in the brain in a right-handed patient, RA, with known right-hemisphere speech representation as determined by intracarotid sodium amobarbital testing. Similar patterns of cerebral blood flow were observed across all three languages (French, Spanish and English), when synonym generation was compared with a silent resting baseline. In particular, several regions in the right inferior frontal cortex were activated. These foci are in locations corresponding to those observed in the left hemisphere in normal right-handed volunteers with presumed left-hemisphere dominance, and in patients known to be left-hemisphere dominant for speech. The lack of anatomical separation of the three languages within the same individual, who acquired two languages early and one language later in life, suggests that at least at this single-word level of analysis, age of acquisition was not a significant factor in the determining of functional organization in the brain.

  19. Theory of mind and the right cerebral hemisphere: refining the scope of impairment.

    PubMed

    Griffin, Richard; Friedman, Ori; Ween, Jon; Winner, Ellen; Happé, Francesca; Brownell, Hiram

    2006-05-01

    The neuropsychological and functional characterisation of mental state attribution ("theory of mind" (ToM)) has been the focus of several recent studies. The literature contains opposing views on the functional specificity of ToM and on the neuroanatomical structures most relevant to ToM. Studies with brain-lesioned patients have consistently found ToM deficits associated with unilateral right hemisphere damage (RHD). Also, functional imaging performed with non-brain-injured adults implicates several specific neural regions, many of which are located in the right hemisphere. The present study examined the separation of ToM impairment from other deficits associated with brain injury. We tested 11 patients with unilateral right hemisphere damage (RHD) and 20 normal controls (NC) on a humour rating task, an emotion rating task, a graded (first-order, second-order) ToM task with non-mentalistic control questions, and two ancillary measures: (1) Trails A and B, in order to assess overall level of impairment and set-shifting abilities associated with executive function, and (2) a homograph reading task to assess central coherence skills. Our findings indicate that RHD can result in a functionally specific deficit in attributing intentional states, particularly those involving second-order attributions. Performance on ToM questions was not reliably related to measures of cognitive impairment; however, performance on non-ToM control questions was reliably predicted by Trails A and B. We also discuss individual RHD patients' performance with attention to lesion locus. Our findings suggest that damage to the areas noted as specialised in neuroimaging studies may not affect ToM performance, and underscore the necessity of combining lesion and imaging studies in determining functional-anatomical relations.

  20. Cerebral stimulation for the affective component of neuropathic pain

    PubMed Central

    Machado, Andre G.; Baker, Kenneth B.; Plow, Ela; Malone, Donald A.

    2012-01-01

    Objective To review the current state of cerebral stimulation for neuropathic pain and to propose that cerebral stimulation should aim at the affective sphere of chronic pain rather than solely focusing on the primary sensory-discriminative sphere. Methods The past and current goals of cerebral stimulation are reviewed as well as its limitations. A novel deep brain stimulation approach is proposed to evaluate this conceptual shift fromsomatosensory to affective sphere of pain targeting Approach Thalamic and other central pain syndromes aretypically intractable to current treatment methods, including cerebral neuromodulation of somatosensory pathways, leading to long-term distress and disability. Our modern understanding of chronic pain pathophysiology is based largely on the neuromatrix theory, where cognitive, affective and sensory-discriminative spheres contribute equally to the overall pain experience. During the last decade, the safety and feasibility of chronic stimulation of neural pathways related to mood and affect has been explored with promising results. Here, we propose a novel approach to modulate the affective sphere of chronic pain by targeting similar networks in patients with treatment-refractory central pain. Our primary goal is not to produce (or measure) analgesia, but rather to modulate the affective burden of chronic. Discussion Cerebral neuromodulation for neuropathic pain has had limited efficacy thus far. Shifting our aim to neural networks related to the affective sphere of pain may allow us to reduce pain conditioning and pain-related disability. Our ultimate goal is to promote rehabilitation from chronic pain - social and occupational. PMID:23094938

  1. Using ipsilateral motor signals in the unaffected cerebral hemisphere as a signal platform for brain-computer interfaces in hemiplegic stroke survivors

    NASA Astrophysics Data System (ADS)

    Bundy, David T.; Wronkiewicz, Mark; Sharma, Mohit; Moran, Daniel W.; Corbetta, Maurizio; Leuthardt, Eric C.

    2012-06-01

    Brain-computer interface (BCI) systems have emerged as a method to restore function and enhance communication in motor impaired patients. To date, this has been applied primarily to patients who have a compromised motor outflow due to spinal cord dysfunction, but an intact and functioning cerebral cortex. The cortical physiology associated with movement of the contralateral limb has typically been the signal substrate that has been used as a control signal. While this is an ideal control platform in patients with an intact motor cortex, these signals are lost after a hemispheric stroke. Thus, a different control signal is needed that could provide control capability for a patient with a hemiparetic limb. Previous studies have shown that there is a distinct cortical physiology associated with ipsilateral, or same-sided, limb movements. Thus far, it was unknown whether stroke survivors could intentionally and effectively modulate this ipsilateral motor activity from their unaffected hemisphere. Therefore, this study seeks to evaluate whether stroke survivors could effectively utilize ipsilateral motor activity from their unaffected hemisphere to achieve this BCI control. To investigate this possibility, electroencephalographic (EEG) signals were recorded from four chronic hemispheric stroke patients as they performed (or attempted to perform) real and imagined hand tasks using either their affected or unaffected hand. Following performance of the screening task, the ability of patients to utilize a BCI system was investigated during on-line control of a one-dimensional control task. Significant ipsilateral motor signals (associated with movement intentions of the affected hand) in the unaffected hemisphere, which were found to be distinct from rest and contralateral signals, were identified and subsequently used for a simple online BCI control task. We demonstrate here for the first time that EEG signals from the unaffected hemisphere, associated with overt and

  2. Differences in somatosensory processing due to dominant hemispheric motor impairment in cerebral palsy

    PubMed Central

    2014-01-01

    Background Although cerebral palsy (CP) is usually defined as a group of permanent motor disorders due to non-progressive disturbances in the developing fetal or infant brain, recent research has shown that CP individuals are also characterized by altered somatosensory perception, increased pain and abnormal activation of cortical somatosensory areas. The present study was aimed to examine hemispheric differences on somatosensory brain processing in individuals with bilateral CP and lateralized motor impairments compared with healthy controls. Nine CP individuals with left-dominant motor impairments (LMI) (age range 5–28 yrs), nine CP individuals with right-dominant motor impairments (RMI) (age range 7–29 yrs), and 12 healthy controls (age range 5–30 yrs) participated in the study. Proprioception, touch and pain thresholds, as well as somatosensory evoked potentials (SEP) elicited by tactile stimulation of right and left lips and thumbs were compared. Results Pain sensitivity was higher, and lip stimulation elicited greater beta power and more symmetrical SEP amplitudes in individuals with CP than in healthy controls. In addition, although there was no significant differences between individuals with RMI and LMI on pain or touch sensitivity, lip and thumb stimulation elicited smaller beta power and more symmetrical SEP amplitudes in individuals with LMI than with RMI. Conclusions Our data revealed that brain processing of somatosensory stimulation was abnormal in CP individuals. Moreover, this processing was different depending if they presented right- or left-dominant motor impairments, suggesting that different mechanisms of sensorimotor reorganization should be involved in CP depending on dominant side of motor impairment. PMID:24410983

  3. Cerebral vasospasm affects arterial critical closing pressure

    PubMed Central

    Varsos, Georgios V; Budohoski, Karol P; Czosnyka, Marek; Kolias, Angelos G; Nasr, Nathalie; Donnelly, Joseph; Liu, Xiuyun; Kim, Dong-Joo; Hutchinson, Peter J; Kirkpatrick, Peter J; Varsos, Vassilis G; Smielewski, Peter

    2015-01-01

    The effect of cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage (SAH) on critical closing pressure (CrCP) has not been fully delineated. Using cerebral impedance methodology, we sought to assess the behavior of CrCP during CVS. As CrCP expresses the sum of intracranial pressure (ICP) and vascular wall tension, we also explored its role in reflecting changes in vascular tone occurring in small vessels distal to spasm. This retrospective analysis was performed using recordings from 52 patients, diagnosed with CVS through transcranial Doppler measurements. Critical closing pressure was calculated noninvasively using arterial blood pressure and blood flow velocity. Outcome was assessed at both discharge and 3 months after ictus with the Glasgow Outcome Scale. The onset of CVS caused significant decreases in CrCP (P=0.025), without any observed significant changes in ICP (P=0.134). Vasospasm induced asymmetry, with CrCP ipsilateral to CVS becoming significantly lower than contralateral (P=0.025). Unfavorable outcomes were associated with a significantly lower CrCP after the onset of CVS (discharge: P=0.014; 3 months after SAH: P=0.020). Critical closing pressure is reduced in the presence of CVS in both temporal and spatial assessments. As ICP remained unchanged during CVS, reduced CrCP most probably reflects a lower wall tension in dilated small vessels distal to spasm. PMID:25465041

  4. Semantic processing in the left versus right cerebral hemispheres following unilateral hand contractions.

    PubMed

    Turner, Casey E; Hahn, Michael E; Kellogg, Ronald T

    2017-03-01

    Unilateral hand contractions increase activation in the motor cortex of the contralateral hemisphere, providing a means to alter the relative degree of activation in the right hemisphere versus the left hemisphere through spreading activation. Prior research reported enhanced verbal creativity as measured by performance on remote associate problems in Hebrew from left-hand contractions (right-hemisphere activation). We sought to extend the previous findings to English problems and to homograph interpretation. In Experiment 1, unilateral hand contractions in fact altered performance on the English remote associates, but in the direction of improved performance following right-hand contractions and left-hemisphere activation. In Experiment 2, the probability of retrieving atypical interpretations of homographs with multiple meanings was least likely for left-hemisphere dominant strong right handers, but the hand contraction manipulation had no effect.

  5. Therapeutic effect of nerve growth factor on cerebral infarction in dogs using the hemisphere anomalous volume ratio of diffusion-weighted magnetic resonance imaging.

    PubMed

    Wang, Yong; Zhang, Hui; Wang, Zhe; Geng, Zuojun; Liu, Huaijun; Yang, Haiqing; Song, Peng; Liu, Qing

    2012-08-25

    A model of focal cerebral ischemic infarction was established in dogs through middle cerebral artery occlusion of the right side. Thirty minutes after occlusion, models were injected with nerve growth factor adjacent to the infarct locus. The therapeutic effect of nerve growth factor against cerebral infarction was assessed using the hemisphere anomalous volume ratio, a quantitative index of diffusion-weighted MRI. At 6 hours, 24 hours, 7 days and 3 months after modeling, the hemisphere anomalous volume ratio was significantly reduced after treatment with nerve growth factor. Hematoxylin-eosin staining, immunohistochemistry, electron microscopy and neurological function scores showed that infarct defects were slightly reduced and neurological function significantly improved after nerve growth factor treatment. This result was consistent with diffusion-weighted MRI measurements. Experimental findings indicate that nerve growth factor can protect against cerebral infarction, and that the hemisphere anomalous volume ratio of diffusion-weighted MRI can be used to evaluate the therapeutic effect.

  6. Therapeutic effect of nerve growth factor on cerebral infarction in dogs using the hemisphere anomalous volume ratio of diffusion-weighted magnetic resonance imaging★

    PubMed Central

    Wang, Yong; Zhang, Hui; Wang, Zhe; Geng, Zuojun; Liu, Huaijun; Yang, Haiqing; Song, Peng; Liu, Qing

    2012-01-01

    A model of focal cerebral ischemic infarction was established in dogs through middle cerebral artery occlusion of the right side. Thirty minutes after occlusion, models were injected with nerve growth factor adjacent to the infarct locus. The therapeutic effect of nerve growth factor against cerebral infarction was assessed using the hemisphere anomalous volume ratio, a quantitative index of diffusion-weighted MRI. At 6 hours, 24 hours, 7 days and 3 months after modeling, the hemisphere anomalous volume ratio was significantly reduced after treatment with nerve growth factor. Hematoxylin-eosin staining, immunohistochemistry, electron microscopy and neurological function scores showed that infarct defects were slightly reduced and neurological function significantly improved after nerve growth factor treatment. This result was consistent with diffusion-weighted MRI measurements. Experimental findings indicate that nerve growth factor can protect against cerebral infarction, and that the hemisphere anomalous volume ratio of diffusion-weighted MRI can be used to evaluate the therapeutic effect. PMID:25624813

  7. [Reactivity of microvessels in the cerebral hemispheres and the skeletal muscles in chicken during second half of embryogenesis].

    PubMed

    Belichenko, V M; Turganbaeva, A S; Shoshenko, K A

    2014-02-01

    At Leghorn hens in the second half of embryogenesis and in 4-day-old chicks are studied reaction volume flow velocity (VF) in the superficial layers of the cerebral hemispheres and in skeletal muscle (Lazer Doppler FIowmetry) after the local influence of norepinephrine and sodium nitroprusside. It is shown that the response to these substances begins to manifest itself in the hemisphere in the last quarter of embryogenesis and authentically expressed by the end of it and in the chickens. It is noted that the response to these substances skeletal muscle VF (according to the new and previously published data on gastrocnemius and pectoral muscle) is also clearly manifested by the end of embryogenesis.

  8. Priming Nouns and Verbs: Differential Influences of Semantic and Grammatical Cues in the Two Cerebral Hemispheres

    ERIC Educational Resources Information Center

    Arambel, Stella R.; Chiarello, Christine

    2006-01-01

    The current experiment investigated how sentential form-class expectancies influenced lexical-semantic priming within each hemisphere. Sentences were presented that led readers to expect a noun or a verb and the sentence-final target word was presented to one visual field/hemisphere for a lexical decision response. Noun and verb targets in the…

  9. The Integration of the Cerebral Hemispheres in Poetry and Mystic Texts.

    ERIC Educational Resources Information Center

    Cashford, Jules

    1979-01-01

    The author explores some of the implications of E. Rossi's hypothesis that "fine literature and poetry is essentially a form by which the words of the left hemisphere give voice to symbols and archetypal patterns of the right" (hemisphere). (Author/PHR)

  10. Low Frequency Fluctuations Reveal Integrated and Segregated Processing among the Cerebral Hemispheres

    PubMed Central

    Gee, Dylan G.; Biswal, Bharat B.; Kelly, Clare; Stark, David E.; Margulies, Daniel S.; Shehzad, Zarrar; Uddin, Lucina Q.; Klein, Donald F.; Banich, Marie T.; Castellanos, F. Xavier; Milham, Michael P.

    2011-01-01

    Resting-state functional magnetic resonance imaging (fMRI) has provided a novel approach for examining interhemispheric interaction, demonstrating a high degree of functional connectivity between homotopic regions in opposite hemispheres. However, heterotopic resting state functional connectivity (RSFC) remains relatively uncharacterized. In the present study, we examine non-homotopic regions, characterizing heterotopic RSFC and comparing it to intrahemispheric RSFC, to examine the impact of hemispheric separation on the integration and segregation of processing in the brain. Resting-state fMRI scans were acquired from 59 healthy participants to examine interregional correlations in spontaneous low frequency fluctuations in BOLD signal. Using a probabilistic atlas, we correlated probability-weighted time series from 112 regions (56 per hemisphere) distributed throughout the entire cerebrum. We compared RSFC for pairings of non-homologous regions located in different hemispheres (heterotopic connectivity) to RSFC for the same pairings when located within hemisphere (intrahemispheric connectivity). For positive connections, connectivity strength was greater within each hemisphere, consistent with integrated intrahemispheric processing. However, for negative connections, RSFC strength was greater between the hemispheres, consistent with segregated interhemispheric processing. These patterns were particularly notable for connections involving frontal and heteromodal regions. The distribution of positive and negative connectivity was nearly identical within and between the hemispheres, though we demonstrated detailed regional variation in distribution. We discuss implications for leading models of interhemispheric interaction. The future application of our analyses may provide important insight into impaired interhemispheric processing in clinical and aging populations. PMID:20570737

  11. Motor, cognitive, and affective areas of the cerebral cortex influence the adrenal medulla

    PubMed Central

    Dum, Richard P.; Levinthal, David J.; Strick, Peter L.

    2016-01-01

    Modern medicine has generally viewed the concept of “psychosomatic” disease with suspicion. This view arose partly because no neural networks were known for the mind, conceptually associated with the cerebral cortex, to influence autonomic and endocrine systems that control internal organs. Here, we used transneuronal transport of rabies virus to identify the areas of the primate cerebral cortex that communicate through multisynaptic connections with a major sympathetic effector, the adrenal medulla. We demonstrate that two broad networks in the cerebral cortex have access to the adrenal medulla. The larger network includes all of the cortical motor areas in the frontal lobe and portions of somatosensory cortex. A major component of this network originates from the supplementary motor area and the cingulate motor areas on the medial wall of the hemisphere. These cortical areas are involved in all aspects of skeletomotor control from response selection to motor preparation and movement execution. The second, smaller network originates in regions of medial prefrontal cortex, including a major contribution from pregenual and subgenual regions of anterior cingulate cortex. These cortical areas are involved in higher-order aspects of cognition and affect. These results indicate that specific multisynaptic circuits exist to link movement, cognition, and affect to the function of the adrenal medulla. This circuitry may mediate the effects of internal states like chronic stress and depression on organ function and, thus, provide a concrete neural substrate for some psychosomatic illness. PMID:27528671

  12. Multiple priming of lexically ambiguous and unambiguous targets in the cerebral hemispheres: the coarse coding hypothesis revisited

    PubMed Central

    Kandhadai, Padmapriya; Federmeier, Kara D.

    2009-01-01

    The coarse coding hypothesis (Jung-Beeman 2005) postulates that the cerebral hemispheres differ in their breadth of semantic activation, with the left hemisphere (LH) activating a narrow, focused semantic field and the right (RH) weakly activating a broader semantic field. In support of coarse coding, studies (e.g., Faust and Lavidor 2003) investigating priming for multiple senses of a lexically ambiguous word have reported a RH benefit. However, studies of mediated priming (Livesay and Burgess 2003; Richards and Chiarello 1995) have failed to find a RH advantage for processing distantly-linked, unambiguous words. To address this debate, the present study made use of a multiple priming paradigm (Balota and Paul, 1996) in which two primes either converged onto the single meaning of an unambiguous, lexically-associated target (LION-STRIPES-TIGER) or diverged onto different meanings of an ambiguous target (KIDNEY-PIANO-ORGAN). In two experiments, participants either made lexical decisions to targets (Experiment 1) or made a semantic relatedness judgment between primes and targets (Experiment 2). In both tasks, for both ambiguous and unambiguous triplets we found equivalent priming strengths and patterns across the two visual fields, counter to the predictions of the coarse coding hypothesis. Priming patterns further suggested that both hemispheres made use of lexical level representations in the lexical decision task and semantic representations in the semantic judgment task. PMID:17459344

  13. Malignant Hemispheric Cerebral Infarction Associated with Idiopathic Systemic Capillary Leak Syndrome

    PubMed Central

    Miyata, Kei; Mikami, Takeshi; Mikuni, Nobuhiro; Aisaka, Wakiko; Irifune, Hideto; Narimatsu, Eichi

    2013-01-01

    Idiopathic systemic capillary leak syndrome (ISCLS) is a rare condition that is characterized by unexplained episodic capillary hyperpermeability due to a shift of fluid and protein from the intravascular to the interstitial space. This results in diffuse general swelling, fetal hypovolemic shock, hypoalbuminemia, and hemoconcentration. Although ISCLS rarely induces cerebral infarction, we experienced a patient who deteriorated and was comatose as a result of massive cerebral infarction associated with ISCLS. In this case, severe hypotensive shock, general edema, hemiparesis, and aphasia appeared after serious antecedent gastrointestinal symptoms. Progressive life-threatening ischemic cerebral edema required decompressive hemicraniectomy. The patient experienced another episode of severe hypotension and limb edema that resulted in multiple extremity compartment syndrome. Treatment entailed forearm and calf fasciotomies. Cerebral edema in the ischemic brain progresses rapidly in patients suffering from ISCLS. Strict control of fluid volume resuscitation and aggressive diuretic therapy may be needed during the post-leak phase of fluid remobilization. PMID:24163674

  14. Independent and Collaborative Contributions of the Cerebral Hemispheres to Emotional Processing

    PubMed Central

    Shobe, Elizabeth R.

    2014-01-01

    Presented is a model suggesting that the right hemisphere (RH) directly mediates the identification and comprehension of positive and negative emotional stimuli, whereas the left hemisphere (LH) contributes to higher level processing of emotional information that has been shared via the corpus callosum. RH subcortical connections provide initial processing of emotional stimuli, and their innervation to cortical structures provides a secondary pathway by which the hemispheres process emotional information more fully. It is suggested that the LH contribution to emotion processing is in emotional regulation, social well-being, and adaptation, and transforming the RH emotional experience into propositional and verbal codes. Lastly, it is proposed that the LH has little ability at the level of emotion identification, having a default positive bias and no ability to identify a stimulus as negative. Instead, the LH must rely on the transfer of emotional information from the RH to engage higher-order emotional processing. As such, either hemisphere can identify positive emotions, but they must collaborate for complete processing of negative emotions. Evidence presented draws from behavioral, neurological, and clinical research, including discussions of subcortical and cortical pathways, callosal agenesis, commissurotomy, emotion regulation, mood disorders, interpersonal interaction, language, and handedness. Directions for future research are offered. PMID:24795597

  15. Is There a Sensitive Period for the Establishment of Linguistic Functions in the Right Cerebral Hemisphere?

    ERIC Educational Resources Information Center

    Vargha-Khadem, Faraneh

    Spelling performance was compared for 50 children who had hemiplegia sustained either prenatally (N=32) or postnatally (N=18) and for four children with hemispherectomies. The group study of subjects with hemiplegia divided the children into four groups based on hemispheric side and age at injury. This approach sought to investigate quantitative…

  16. Factors affecting the cerebral network in brain tumor patients.

    PubMed

    Heimans, Jan J; Reijneveld, Jaap C

    2012-06-01

    Brain functions, including cognitive functions, are frequently disturbed in brain tumor patients. These disturbances may result from the tumor itself, but also from the treatment directed against the tumor. Surgery, radiotherapy and chemotherapy all may affect cerebral functioning, both in a positive as well as in a negative way. Apart from the anti-tumor treatment, glioma patients often receive glucocorticoids and anti-epileptic drugs, which both also have influence on brain functioning. The effect of a brain tumor on cerebral functioning is often more global than should be expected on the basis of the local character of the disease, and this is thought to be a consequence of disturbance of the cerebral network as a whole. Any network, whether it be a neural, a social or an electronic network, can be described in parameters assessing the topological characteristics of that particular network. Repeated assessment of neural network characteristics in brain tumor patients during their disease course enables study of the dynamics of neural networks and provides more insight into the plasticity of the diseased brain. Functional MRI, electroencephalography and especially magnetoencephalography are used to measure brain function and the signals that are being registered with these techniques can be analyzed with respect to network characteristics such as "synchronization" and "clustering". Evidence accumulates that loss of optimal neural network architecture negatively impacts complex cerebral functioning and also decreases the threshold to develop epileptic seizures. Future research should be focused on both plasticity of neural networks and the factors that have impact on that plasticity as well as the possible role of assessment of neural network characteristics in the determination of cerebral function during the disease course.

  17. Marc Dax and the discovery of the lateralisation of language in the left cerebral hemisphere.

    PubMed

    Manning, L; Thomas-Antérion, C

    2011-12-01

    In 1836, Marc Dax presented a revolutionary conclusion based on both his clinical observations and reports from the literature: the localisation of language in the left hemisphere. Twenty-seven years later, his son, Gustave Dax, extended and enriched his work. Their involvement in 19th century neuropsychology is impressive and recognition should have been considerable. However, according to the vast majority of historians of neurology, neuropsychology and aphasiology, the priority in establishing the dominance of the left brain hemisphere for speech goes to Paul Broca in an undivided way. Is it possible that Marc Dax's and his son, Gustave Dax's works were entirely unknown? Were they known and utterly forgotten? Were they ignored? How did we get to know that they existed? The aim of the present paper is to try to answer those and other questions and to demonstrate that there is abundance of data pointing out that the priority of the discovery of left hemisphere dominance for speech ought to be, at least, shared by Dax and Broca.

  18. Reading laterally: the cerebral hemispheric use of spatial frequencies in visual word recognition.

    PubMed

    Tadros, Karine; Dupuis-Roy, Nicolas; Fiset, Daniel; Arguin, Martin; Gosselin, Frédéric

    2013-01-04

    It is generally accepted that the left hemisphere (LH) is more capable for reading than the right hemisphere (RH). Left hemifield presentations (initially processed by the RH) lead to a globally higher error rate, slower word identification, and a significantly stronger word length effect (i.e., slower reaction times for longer words). Because the visuo-perceptual mechanisms of the brain for word recognition are primarily localized in the LH (Cohen et al., 2003), it is possible that this part of the brain possesses better spatial frequency (SF) tuning for processing the visual properties of words than the RH. The main objective of this study is to determine the SF tuning functions of the LH and RH for word recognition. Each word image was randomly sampled in the SF domain using the SF bubbles method (Willenbockel et al., 2010) and was presented laterally to the left or right visual hemifield. As expected, the LH requires less visual information than the RH to reach the same level of performance, illustrating the well-known LH advantage for word recognition. Globally, the SF tuning of both hemispheres is similar. However, these seemingly identical tuning functions hide important differences. Most importantly, we argue that the RH requires higher SFs to identify longer words because of crowding.

  19. The role of the right cerebral hemisphere in processing novel metaphoric expressions taken from poetry: a divided visual field study.

    PubMed

    Faust, M; Mashal, N

    2007-03-02

    Previous research suggests that the right hemisphere (RH) may contribute uniquely to the processing of metaphoric language. However, most studies have focused on familiar metaphoric expressions. The present study used the divided visual field paradigm to examine the role of the right cerebral hemisphere in processing novel metaphoric expressions taken from poetry. In two experiments, participants were presented with four types of word pairs, literal, conventional metaphoric and novel metaphoric expressions and unrelated word pairs, and asked to perform a semantic judgment task. Two different SOAs: 400 and 1100 ms were used. The results of both experiments showed that responses to LVF/RH presented target words were more accurate and faster than responses to RVF/LH target words for novel metaphoric expressions, but not for other types of word pairs. These results support previous research indicating that during word recognition, the RH activates a broader range of related meanings than the LH, including novel, nonsalient meanings. The findings thus suggest that the RH may be critically involved in at least one important component of novel metaphor comprehension, i.e., the integration of the individual meanings of two seemingly unrelated concepts into a meaningful metaphoric expression.

  20. Structural MRI of carotid artery atherosclerotic lesion burden and characterization of hemispheric cerebral blood flow before and after carotid endarterectomy.

    PubMed

    Jones, C E; Wolf, R L; Detre, J A; Das, B; Saha, P K; Wang, J; Zhang, Y; Song, H K; Wright, A C; Mohler, E M; Fairman, R M; Zager, E L; Velazquez, O C; Golden, M A; Carpenter, J P; Wehrli, F W

    2006-04-01

    Collateral circulation plays a major role in maintaining cerebral blood flow (CBF) in patients with internal carotid artery (ICA) stenosis. CBF can remain normal despite severe ICA stenosis, making the benefit of carotid endarterectomy (CEA) or stenting difficult to assess. Before and after surgery, we assessed CBF supplied through the ipsilateral (stenotic) or contralateral ICA individually with a novel hemisphere-selective arterial spin-labeling (ASL) perfusion MR technique. We further explored the relationship between CBF and ICA obstruction ratio (OR) acquired with a multislice black-blood imaging sequence. For patients with unilateral ICA stenosis (n = 19), conventional bilateral labeling did not reveal interhemispheric differences. With unilateral labeling, CBF in the middle cerebral artery (MCA) territory on the surgical side from the ipsilateral supply (53.7 +/- 3.3 ml/100 g/min) was lower than CBF in the contralateral MCA territory from the contralateral supply (58.5 +/- 2.7 ml/100 g/min), although not statistically significant (p = 0.09). The ipsilateral MCA territory received significant (p = 0.02) contralateral supply (7.0 +/- 2.7 ml/100 g/min), while ipsilateral supply to the contralateral side was not reciprocated. After surgery (n = 11), ipsilateral supply to the MCA territory increased from 57.3 +/- 5.7 to 67.3 +/- 5.4 ml/100 g/min (p = 0.03), and contralateral supply to the ipsilateral MCA territory decreased. The best predictor of increased CBF on the side of surgery was normalized presurgical ipsilateral supply (r(2) = 0.62, p = 0.004). OR was less predictive of change, although the change in normalized contralateral supply was negatively correlated with OR(excess) (=OR(ipsilateral) - OR(contralateral)) (r(2) = 0.58, p = 0.006). The results demonstrate the effect of carotid artery stenosis on blood supply to the cerebral hemispheres, as well as the relative role of collateral pathways before surgery and redistribution of blood flow through these

  1. Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

    SciTech Connect

    Wu, J.C.; Hagman, J.; Buchsbaum, M.S.; Blinder, B.; Derrfler, M.; Tai, W.Y.; Hazlett, E.; Sicotte, N. )

    1990-03-01

    Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using (18F)-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion that bulimia is a diagnostic grouping distinct from these disorders.

  2. Quantitation and morphological characterization of rapid axon and dendritic growth from single cerebral hemispheric neurons in hydrated collagen lattice culture.

    PubMed

    Coates, P W

    1986-02-01

    Quantitative and qualitative data are reported for single cerebral hemispheric neurons in a 3-dimensional hydrated collagen lattice (HCL) culture system. Individual neurons not in contact with other cells or cell processes, including synapses, rapidly displayed two morphologically distinct classes of processes that could be traced from origin to termination: long thin processes interpreted as being axons, and shorter tapering and sometimes branched processes interpreted as being dendrites. Axons and dendrites of single neurons that had at least one process longer than the cell body were measured on each of 3 days after plating using an image analysis system coupled to a phase-contrast microscope and a microcomputer. Mean lengths of axons and dendrites alone or combined as total new growth per neuron, increased 3- to 5-fold and were as high as 745, 694 and 1226 microns respectively after 3 days in HCL, although some individual axons measured over 1500 microns. Other indices of neuron growth and differentiation increased 1- to 5-fold including the number of primary processes, branch points, segments and growth cones. Phase-contrast microscopy, staining with Nissl and silver, and scanning and transmission electron microscopy demonstrated many single multipolar and other neurons with axons, dendrites and well-differentiated properties. The data show that individual central nervous system neurons have an inherent capacity to quickly express characteristic differentiated features and also to grow rapidly in HCL.

  3. Cerebral Assymetry: Changes in Factors Affecting Its Development.

    ERIC Educational Resources Information Center

    Molfese, Dennis L.; And Others

    This study attempts to evaluate procedures for studying hemispheric differences in newborn human infants and to determine what acoustic characteristics of speech sounds will trigger a left hemisphere (LH) repsonse. Within 48 hours of birth, 14 neonates were individually administered five aural stimuli which comprised two speech syllables, two…

  4. Sound lateralisation in patients with left or right cerebral hemispheric lesions: relation with unilateral visuospatial neglect

    PubMed Central

    Tanaka, H.; Hachisuka, K.; Ogata, H.

    1999-01-01

    OBJECTIVES—To localise the brain lesion that causes disturbances of sound lateralisation and to examine the correlation between such deficit and unilateral visuospatial neglect.
METHOD—There were 29 patients with right brain damage, 15 patients with left brain damage, and 22 healthy controls, who had normal auditory and binaural thresholds. A device was used that delivered sound to the left and right ears with an interaural time difference using headphones. The amplitude (an index of ability to detect sound image shifts from the centre) and midpoint (an index of deviation of the interaural time difference range perceived as the centre) parameters of interaural time difference were analysed in each subject using 10 consecutive stable saw toothed waves.
RESULTS—The amplitude of interaural time difference was significantly higher in patients with right brain damage than in controls. The midpoint of the interaural time difference was significantly more deviated in patients with right brain damage than in those with left brain damage and controls (p<0.05). Patients with right brain damage with lesions affecting both the parietal lobe and auditory pathway showed a significantly higher amplitude and deviated midpoint than the controls, whereas right brain damage with involvement of only the parietal lobe showed a midpoint significantly deviated from the controls (p<0.05). Abnormal sound lateralisation correlated with unilateral visuospatial neglect (p<0.05).
CONCLUSIONS—The right parietal lobe plays an important part in sound lateralisation. Sound lateralisation is also influenced by lesions of the right auditory pathway, although the effect of such lesions is less than that of the right parietal lobe. Disturbances of sound lateralisation correlate with unilateral visuospatial neglect.

 PMID:10486395

  5. A common network in the left cerebral hemisphere represents planning of tool use pantomimes and familiar intransitive gestures at the hand-independent level.

    PubMed

    Króliczak, Gregory; Frey, Scott H

    2009-10-01

    Evidence from neuropsychology and neuroimaging implicates parietal and frontal areas of the left cerebral hemisphere in the representation of skills involving the use of tools and other artifacts. On the basis of neuropsychological data, it has been claimed that 1) independent mechanisms within the left hemisphere may support the representation of these skills (transitive actions) versus meaningful gestures that do not involve manipulating objects (intransitive actions), and 2) both cerebral hemispheres may participate in the representation of intransitive gestures. Functional magnetic resonance imaging was used to test these hypotheses in 12 healthy adults while they planned and executed tool use pantomimes or intransitive gestures with their dominant right (Exp. 1) or nondominant left (Exp. 2) hands. Even when linguistic processing demands were controlled, planning either type of action was associated with asymmetrical increases in the same regions of left parietal (the intraparietal sulcus, supramarginal gyrus, and caudal superior parietal lobule) and dorsal premotor cortices. Effects were greater for tool use pantomimes, but only when the right hand was involved. Neither group nor individual analyses revealed evidence for greater bilateral activity during intransitive gesture planning. In summary, at the hand-independent level, transitive and intransitive actions are represented in a common, left-lateralized praxis network.

  6. Functional asymmetry of the cerebral hemispheres: its role in the pathogenesis of ectromelia and melanoma in (CBAxC57BL/6)F1 mice.

    PubMed

    Abramov, V V; Gontova, I A; Ignatiev, I M; Gelfgat, E L; Kozlov, V A

    2010-09-01

    The aim of the present work was to identify the role of functional asymmetry in the cerebral hemispheres in the pathogenesis of infectious and oncological pathology in (CBAxC57BL/6)F1 mice. Mice with lefthemisphere dominance of motor functions ("right-handers") were found to be more resistant to infection with ectromelia virus and to show slower growth of tumors after subcutaneous injection of B-16 melanoma than animals with right-hemisphere dominance of motor control ("left-handers"). Thus, this report provides the first evidence for the role of functional asymmetry of the nervous system in the pathogenesis of ectromelia and melanoma (B-16) in (CBAxC57BL/6)F1 mice.

  7. The Effects of Multiple Script Priming on Word Recognition by the Two Cerebral Hemispheres: Implications for Discourse Processing

    ERIC Educational Resources Information Center

    Faust, Miriam; Barak, Ofra; Chiarello, Christine

    2006-01-01

    The present study examined left (LH) and right (RH) hemisphere involvement in discourse processing by testing the ability of each hemisphere to use world knowledge in the form of script contexts for word recognition. Participants made lexical decisions to laterally presented target words preceded by centrally presented script primes (four…

  8. Amelioration by black tea of sodium fluoride-induced changes in protein content of cerebral hemisphere, cerebellum and medulla oblongata in brain region of mice.

    PubMed

    Trivedi, Mrugesh H; Verma, Ramtej J; Chinoy, Niloufer J

    2007-01-01

    Oral administration of sodium fluoride (NaF, 6 and 12 mg/kg body weight/day) to Swiss strain male albino mice for 30 days caused significant dose-dependant reduction in the content of acidic, basic, neutral, and total protein in cerebral hemisphere, cerebellum and medulla oblongata region of brain. After 30 days of NaF treatment, followed by withdrawal of treatment for 30 days, partial but significant amelioration occurred. Administration of 2% black tea extract alone for 30 days did not cause any significant effect. However, concurrent administration of NaF and black tea extract for 30 days caused significant amelioration in all parameters studied.

  9. Hemi-ovariectomies promote a decrease in the dendritic lengths of CA1 and CA3 neurons: A dimorphic effect of the cerebral hemispheres.

    PubMed

    Durán, Dolores Adriana Bravo; Silva Gómez, Adriana Berenice; Rosas, Ana Coral Gutiérrez; Trujillo, Angélica

    2017-03-03

    Certain structures of the central nervous system (CNS) are morphologically and functionally related to the ovaries. Ovariectomy has been used to study the functional role of the ovaries in the CNS, as well as the role of the CNS on the reproductive system. In the present study, the effects of left and right hemi-ovariectomy on the morphology of pyramidal neurons from the CA1 and CA3 regions of the ventral hippocampus were studied. During the estrus phase, female Long-Evans rats underwent either left and right hemi-ovariectomies or left and right sham surgeries. Three estrous cycles later, the animals were sacrificed, and their brains were processed in Golgi-Cox stain and analyzed by the Sholl method to calculate the dendritic length of the CA1 and CA3 neurons of the left and right hemispheres. The results indicate that the dendritic lengths of the basilar and apical arbors of the CA1 neurons from the left hemisphere were shorter after both left and right hemi-ovariectomy, while the CA1 neurons from the right hemisphere were not affected by either procedure. However, the basilar dendritic arbors of the CA3 neurons from both hemispheres were affected by right hemi-ovariectomy. The spine density only decreased in the apical arbors in the CA3 neurons from the left hemisphere of rats that underwent right hemi-ovariectomy. This study's results indicate that hemi-ovariectomy in adult rats changes in the morphology of the CA1 and CA3 pyramidal neurons in the ventral hippocampus and that there are dimorphic responses between the hemispheres.

  10. Sevoflurane affects evoked electromyography monitoring in cerebral palsy

    PubMed Central

    Chen, Xin; Xu, Lufeng; Wang, Yuanlin; Xu, Feng; Du, Yemu

    2016-01-01

    Abstract Background To explore the effect of sevoflurane inhalation anesthesia on evoked electromyography monitoring of spinal nerve root in children associated with cerebral palsy. Methodology Children with cerebral palsy (n=40) were selected and further divided into 1MAC (minimum alveolar concentration) sevoflurane group and 2MAC sevoflurane group. Following the induction of anesthesia, Nicolet Endeavor-CR16 channel electrophysiological monitor was used to implement three times of successive electrical stimulation with interval of 5 sec at 3.50 mA. Results Our results suggested a statistical significance of amplitude retention ratio and latency in the sevoflurane inhalation time (P<0.01), with an interaction effect between the sevoflurane inhalation time and concentration for amplitude retention ratio (P<0.01), while there is no interaction effect between the sevoflurane inhalation time and concentration for latency (P>0.05). Compared to 1MAC sevoflurane group, the amplitude retention ratio of 2MAC sevoflurane group decreased remarkably (P<0.01) and the latency of 2MAC sevoflurane group extended at T3 and T4 (P<0.05 or P<0.01). Conclusions In evoked electromyography monitoring of spinal nerve root in children with cerebral palsy, with the increasing of concentration and duration of sevoflurane inhalation, evoked electromyogram retention ratio reduces gradually, latency extends and the retention ratio has more changes than the latency. PMID:28352782

  11. Assessing the effect of unilateral cerebral revascularisation on the vascular reactivity of the non-intervened hemisphere: a retrospective observational study

    PubMed Central

    Sam, Kevin; Poublanc, Julien; Sobczyk, Olivia; Han, Jay S; Battisti-Charbonney, Anne; Mandell, Daniel M; Tymianski, Michael; Crawley, Adrian P; Fisher, Joseph A; Mikulis, David J

    2015-01-01

    Objectives Unilateral haemodynamically significant large-vessel intracranial stenosis may be associated with reduced blood-oxygen-level-dependent (BOLD) cerebrovascular reactivity (CVR), an indicator of autoregulatory reserve. Reduced CVR has been associated with ipsilateral cortical thinning and loss in cognitive function. These effects have been shown to be reversible following revascularisation. Our aim was to study the effects of unilateral revascularisation on CVR in the non-intervened hemisphere in bilateral steno-occlusive or Moyamoya disease. Study Design A retrospective observational study. Setting A routine follow-up assessment of CVR after a revascularisation procedure at a research teaching hospital in Toronto (Journal wants us to generalise). Participants Thirteen patients with bilateral Moyamoya disease (age range 18 to 52 years; 3 males), seven patients with steno-occlusive disease (age range 18 to 78 years; six males) and 27 approximately age-matched normal control subjects (age range 19–71 years; 16 males) with no history or findings suggestive of any neurological or systemic disease. Intervention Participants underwent BOLD CVR MRI using computerised prospective targeting of CO2, before and after unilateral revascularisation (extracranial–intracranial bypass, carotid endarterectomy or encephaloduroarteriosynangiosis). Pre-revascularisation and post-revascularisation CVR was assessed in each major arterial vascular territory of both hemispheres. Results As expected, surgical revascularisation improved grey matter CVR in the middle cerebral artery (MCA) territory of the intervened hemisphere (0.010±0.023 to 0.143±0.010%BOLD/mm Hg, p<0.01). There was also a significant post-revascularisation improvement in grey matter CVR in the MCA territory of the non-intervened hemisphere (0.101±0.025 to 0.165±0.015%BOLD/mm Hg, p<0.01). Conclusions Not only does CVR improve in the hemisphere ipsilateral to a flow restoration procedure, but it

  12. A case of expressive-vocal amusia in a right-handed patient with left hemispheric cerebral infarction.

    PubMed

    Uetsuki, Shizuka; Kinoshita, Hiroshi; Takahashi, Ryuichi; Obata, Satoshi; Kakigi, Tatsuya; Wada, Yoshiko; Yokoyama, Kazumasa

    2016-03-01

    A 53-year-old right-handed woman had an extensive lesion in the left hemisphere due to an infarction caused by vasospasm secondary to subarachnoid bleeding. She exhibited persistent expressive-vocal amusia with no symptoms of aphasia. Evaluation of the patient's musical competence using the Montreal Battery for Evaluation of Amusia, rhythm reproduction tests, acoustic analysis of pitch upon singing familiar music, Japanese standard language tests, and other detailed clinical examinations revealed that her amusia was more dominantly related to pitch production. The intactness of her speech provided strong evidence that the right hemisphere played a major role in her linguistic processing. Data from functional magnetic resonance imaging while she was singing a familiar song, a scale, and reciting lyrics indicated that perilesional residual activation in the left hemisphere was associated with poor pitch production, while right hemispheric activation was involved in linguistic processing. The localization of infarction more anterior to the left Sylvian fissure might be related to the dominant deficits in expressive aspects of the singing of the patient. Compromised motor programming producing a single tone may have made a major contribution to her poor singing. Imperfect auditory feedback due to borderline perceptual ability or improper audio-motor associations might also have played a role.

  13. Neurology of Affective Prosody and Its Functional-Anatomic Organization in Right Hemisphere

    ERIC Educational Resources Information Center

    Ross, Elliott D.; Monnot, Marilee

    2008-01-01

    Unlike the aphasic syndromes, the organization of affective prosody in brain has remained controversial because affective-prosodic deficits may occur after left or right brain damage. However, different patterns of deficits are observed following left and right brain damage that suggest affective prosody is a dominant and lateralized function of…

  14. Projections from Bed Nuclei of the Stria Terminalis, Magnocellular Nucleus: Implications for Cerebral Hemisphere Regulation of Micturition, Defecation, and Penile Erection

    PubMed Central

    DONG, HONG-WEI; SWANSON, LARRY W.

    2008-01-01

    The basic structural organization of axonal projections from the small but distinct magnocellular and ventral nuclei (of the bed nuclei of the stria terminalis) were analyzed with the PHAL anterograde tract tracing method in adult male rats. The former's overall projection pattern is complex, with over 80 distinct terminal fields ipsilateral to injection sites. Innervated regions in the cerebral hemisphere and brainstem fall into 9 general functional categories: cerebral nuclei, behavior control column, orofacial motor-related, humorosensory/thirst-related, brainstem autonomic control network, neuroendocrine, hypothalamic visceromotor pattern generator network, thalamocortical feedback loops, and behavioral state control. The most novel findings indicate that the magnocellular nucleus projects to virtually all known major parts of the brain network that controls pelvic functions including micturition, defecation, and penile erection—as well as to brain networks controlling nutrient and body water homeostasis. This and other evidence suggests that the magnocellular nucleus is part of a cortico-striatopallidal differentiation modulating and coordinating pelvic functions with the maintenance of nutrient and body water homeostasis. Projections of the ventral nucleus are a subset of those generated by the magnocellular nucleus, with the obvious difference that the ventral nucleus does not project detectably to Barrington's nucleus, the subfornical organ, the median preoptic and parastrial nuclei, the neuroendocrine system, and midbrain orofacial motor-related regions. PMID:16304682

  15. Cerebral Asymmetries and Reading Acquisition

    ERIC Educational Resources Information Center

    Pirozzolo, Francis J.

    1978-01-01

    Reviewed are historical developments regarding the concepts of cerebral localization, and analyzed are implications of current research on the role of the cerebral hemispheres in reading disorders. (CL)

  16. How will climate change affect explosive cyclones in the extratropics of the Northern Hemisphere?

    NASA Astrophysics Data System (ADS)

    Seiler, C.; Zwiers, F. W.

    2016-06-01

    Explosive cyclones are rapidly intensifying low pressure systems generating severe wind speeds and heavy precipitation primarily in coastal and marine environments. This study presents the first analysis on how explosive cyclones respond to climate change in the extratropics of the Northern Hemisphere. An objective-feature tracking algorithm is used to identify and track cyclones from 23 CMIP5 climate models for the recent past (1981-1999) and future (2081-2099). Explosive cyclones are projected to shift northwards by about 2.2^circ latitude on average in the northern Pacific, with fewer and weaker events south of 45^circ hbox {N}, and more frequent and stronger events north of this latitude. This shift is correlated with a poleward shift of the jet stream in the inter-model spread (R=0.56). In the Atlantic, the total number of explosive cyclones is projected to decrease by about 17 % when averaging across models, with the largest changes occurring along North America's East Coast. This reduction is correlated with a decline in the lower-tropospheric Eady growth rate (R=0.51), and is stronger for models with smaller frequency biases (R=-0.65). The same region is also projected to experience a small intensification of explosive cyclones, with larger vorticity values for models that predict stronger increases in the speed of the jet stream (R=0.58). This strengthening of the jet stream is correlated with an enhanced sea surface temperature gradient in the North Atlantic (R=-0.63). The inverse relationship between model bias and projection, and the role of model resolution are discussed.

  17. How Will Climate Change Affect Explosive Cyclones in the Extratropics of the Northern Hemisphere?

    NASA Astrophysics Data System (ADS)

    Seiler, C.; Zwiers, F. W.

    2015-12-01

    Explosive cyclones are rapidly intensifying low pressure systems generating severe wind speeds and heavy precipitation primarily in coastal and marine environments, such as the March 2014 nor'easter which developed along the United States coastline, with hurricane force winds in eastern Maine and the Maritimes. This study presents the first analysis on how explosive cyclones respond to climate change in the extratropics of the Northern Hemisphere. An objective-feature tracking algorithm is used to identify and track cyclones from 23 CMIP5 climate models for the recent past (1981-1999) and future (2081-2099). Explosive cyclones are projected to shift northwards by about 2.2° latitude on average in the northern Pacific, with fewer and weaker events south of 45°N, and more frequent and stronger events north of this latitude. This shift is correlated with a poleward shift of the jet stream in the inter-model spread (R = 0.56). In the Atlantic, the total number of explosive cyclones is projected to decrease by about 17% when averaging across models, with the largest changes occurring along North America's East Coast. This reduction is correlated with a decline in the lower-tropospheric Eady growth rate (R = 0.51), and is stronger for models with smaller frequency biases (R = -0.65). The same region is also projected to experience a small intensification of explosive cyclones, with larger vorticity values for models that predict stronger increases in the speed of the jet stream (R = 0.58). This strengthening of the jet stream is correlated with an enhanced sea surface temperature gradient in the North Atlantic (R = -0.63). The inverse relationship between model bias and projection, and the role of model resolution are discussed.

  18. HIV and chronic methamphetamine dependence affect cerebral blood flow.

    PubMed

    Ances, Beau M; Vaida, Florin; Cherner, Mariana; Yeh, Melinda J; Liang, Christine L; Gardner, Carly; Grant, Igor; Ellis, Ronald J; Buxton, Richard B

    2011-09-01

    Human immunodeficiency virus (HIV) and methamphetamine (METH) dependence are independently associated with neuronal dysfunction. The coupling between cerebral blood flow (CBF) and neuronal activity is the basis of many task-based functional neuroimaging techniques. We examined the interaction between HIV infection and a previous history of METH dependence on CBF within the lenticular nuclei (LN). Twenty-four HIV-/METH-, eight HIV-/METH+, 24 HIV+/METH-, and 15 HIV+/METH+ participants performed a finger tapping paradigm. A multiple regression analysis of covariance assessed associations and two-way interactions between CBF and HIV serostatus and/or previous history of METH dependence. HIV+ individuals had a trend towards a lower baseline CBF (-10%, p = 0.07) and greater CBF changes for the functional task (+32%, p = 0.01) than HIV- subjects. Individuals with a previous history of METH dependence had a lower baseline CBF (-16%, p = 0.007) and greater CBF changes for a functional task (+33%, p = 0.02). However, no interaction existed between HIV serostatus and previous history of METH dependence for either baseline CBF (p = 0.53) or CBF changes for a functional task (p = 0.10). In addition, CBF and volume in the LN were not correlated. A possible additive relationship could exist between HIV infection and a history of METH dependence on CBF with a previous history of METH dependence having a larger contribution. Abnormalities in CBF could serve as a surrogate measure for assessing the chronic effects of HIV and previous METH dependence on brain function.

  19. Effectiveness of Adaptive Pretend Play on Affective Expression and Imagination of Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Hsieh, Hsieh-Chun

    2012-01-01

    Purpose: Children with cerebral palsy (CP) have difficulty participating in role-pretending activities. The concept of adaptive play makes play accessible by modifying play materials for different needs or treatment goals for children with CP. This study examines the affective expressions and imagination in children with CP as a function of…

  20. Does Intellectual Disability Affect the Development of Dental Caries in Patients with Cerebral Palsy?

    ERIC Educational Resources Information Center

    Moreira, Rafaela Nogueira; Alcantara, Carlos Eduardo Pinto; Mota-Veloso, Isabella; Marinho, Sandra Aparecida; Ramos-Jorge, Maria L.; Oliveira-Ferreira, Fernanda

    2012-01-01

    The aim of this study was to evaluate if the severity of intellectual disability is a factor that affects the development of dental cavities in patients with cerebral palsy. This cross-sectional study was conducted on 165 individuals who were selected from a physical rehabilitation center, a special public school and a regular public school. Of…

  1. Dopamine therapy does not affect cerebral autoregulation during hypotension in newborn piglets

    PubMed Central

    Hahn, Gitte Holst; Greisen, Gorm

    2017-01-01

    Background Hypotensive neonates who have been treated with dopamine have poorer neurodevelopmental outcome than those who have not been treated with dopamine. We speculate that dopamine stimulates adrenoceptors on cerebral arteries causing cerebral vasoconstriction. This vasoconstriction might lead to a rightward shift of the cerebral autoregulatory curve; consequently, infants treated with dopamine would have a higher risk of low cerebral blood flow at a blood pressure that is otherwise considered “safe”. Methods In anaesthetized piglets, perfusion of the brain, monitored with laser-doppler flowmetry, and cerebral venous saturation was measured at different levels of hypotension. Each piglet was studied in two phases: a phase with stepwise decreases in MAP and a phase with stepwise increases in MAP. We randomized the order of the two phases, whether dopamine was given in the first or second phase, and the infusion rate of dopamine (10, 25, or 40 μg/kg/min). In/deflation of a balloon catheter, placed in vena cava, induced different levels of hypotension. At each level of hypotension, fluctuations in MAP were induced by in/deflations of a balloon catheter in descending aorta. Results During measurements, PaCO2 and arterial saturation were stable. MAP levels ranged between 14 and 82 mmHg. Cerebral autoregulation (CA) capacity was calculated as the ratio between %-change in cerebrovascular resistance and %-change in MAP induced by the in/deflation of the arterial balloon. A breakpoint in CA capacity was identified at a MAP of 38±18 mmHg without dopamine and at 44±18, 31±14, and 24±14 mmHg with dopamine infusion rates of 10, 25, and 40 μg/kg/min (p = 0.057). Neither the index of steady-state cerebral perfusion nor cerebral venous saturation were affected by dopamine infusion. Conclusion Dopamine infusion tended to improve CA capacity at low blood pressures while an index of steady-state cerebral blood flow and cerebral venous saturation were unaffected by

  2. Retrospective study of factors affecting employability of individuals with cerebral palsy in Japan.

    PubMed

    Tobimatsu, Y; Nakamura, R

    2000-12-01

    The purpose of this study was to investigate the characteristics of individuals with cerebral palsy that affected their ability to find a job in Japan. A retrospective nonrandomized descriptive study was performed. Subjects were 99 individuals with cerebral palsy who were eligible to have a vocational training at the National Rehabilitation Center for the Disabled after graduation from high school. All of them were able to perform ADL unassistedly. The mean age of the subjects was 19.9 years (range, 18 to 33) and the mean intelligence quotient measured by WAIS-R was 78.5 (range, 46 to 110). Walking ability, being female and experience of learning in a regular middle high school were significant explanatory variables in the multiple regression equation. The ability of individuals with cerebral palsy to get a job in Japan in the 1990's was largely determined by being able to walk and having an education in a regular school.

  3. Argon does not affect cerebral circulation or metabolism in male humans

    PubMed Central

    Kazmaier, Stephan; Hoeks, Sanne Elisabeth; Stolker, Robert Jan; Coburn, Marc; Weyland, Andreas

    2017-01-01

    Objective Accumulating data have recently underlined argon´s neuroprotective potential. However, to the best of our knowledge, no data are available on the cerebrovascular effects of argon (Ar) in humans. We hypothesized that argon inhalation does not affect mean blood flow velocity of the middle cerebral artery (Vmca), cerebral flow index (FI), zero flow pressure (ZFP), effective cerebral perfusion pressure (CPPe), resistance area product (RAP) and the arterio-jugular venous content differences of oxygen (AJVDO2), glucose (AJVDG), and lactate (AJVDL) in anesthetized patients. Materials and methods In a secondary analysis of an earlier controlled cross-over trial we compared parameters of the cerebral circulation under 15 minutes exposure to 70%Ar/30%O2 versus 70%N2/30%O2 in 29 male patients under fentanyl-midazolam anaesthesia before coronary surgery. Vmca was measured by transcranial Doppler sonography. ZFP and RAP were estimated by linear regression analysis of pressure-flow velocity relationships of the middle cerebral artery. CPPe was calculated as the difference between mean arterial pressure and ZFP. AJVDO2, AJVDG and AJVDL were calculated as the differences in contents between arterial and jugular-venous blood of oxygen, glucose, and lactate. Statistical analysis was done by t-tests and ANOVA. Results Mechanical ventilation with 70% Ar did not cause any significant changes in mean arterial pressure, Vmca, FI, ZFP, CPPe, RAP, AJVDO2, AJVDG, and AJVDL. Discussion Short-term inhalation of 70% Ar does not affect global cerebral circulation or metabolism in male humans under general anaesthesia. PMID:28207907

  4. Looking at human eyes affects contralesional stimulus processing after right hemispheric stroke.

    PubMed

    Maravita, A; Posteraro, L; Husain, M; Vuilleumier, P; Schwartz, S; Driver, J

    2007-10-16

    Human eyes are a powerful social cue that may automatically attract the attention of an observer. Here we tested whether looking toward open human eyes, as often arises in standard clinical "confrontation" tests, may affect contralesional errors in a group of right brain-damaged patients showing visual extinction. Patients were requested to discriminate peripheral shape-targets presented on the left, right, or bilaterally. On each trial they also saw a central task-irrelevant stimulus, comprising an image of the eye sector of a human face, with those seen eyes open or closed. The conditions with central eye stimuli open (vs closed) induced more errors for contralesional peripheral targets, particularly for bilateral trials. These results suggest that seeing open eyes in central vision may attract attentional resources there, reducing attention to the periphery, particularly for the affected contralesional side. The seen gaze of the examiner may thus need to be considered during confrontation testing and may contribute to the effectiveness of that clinical procedure.

  5. Projections from Bed Nuclei of the Stria Terminalis, Dorsomedial Nucleus: Implications for Cerebral Hemisphere Integration of Neuroendocrine, Autonomic, and Drinking Responses

    PubMed Central

    DONG, HONG-WEI; SWANSON, LARRY W.

    2008-01-01

    The overall projection pattern of a tiny bed nuclei of the stria terminalis anteromedial group differentiation, the dorsomedial nucleus (BSTdm), was analyzed with the PHAL anterograde pathway-tracing method in rats. Many brain regions receive a relatively moderate to strong input from the BSTdm. They fall into 8 general categories: humeral sensory-related (subfornical organ and median preoptic nucleus—involved in initiating drinking behavior and salt appetite), neuroendocrine system (magnocellular: oxytocin, vasopressin; parvicellular: gonadotropin-releasing hormone, somatostatin, thyrotropin-releasing hormone, corticotropin-releasing hormone), central autonomic control network (central amygdalar nucleus, BST anterolateral group, descending paraventricular hypothalamic nucleus, retrochiasmatic area, ventrolateral periaqueductal gray, Barrington's nucleus), hypothalamic visceromotor pattern generator network (5 of 6 known components), behavior control column (ingestive: descending paraventricular nucleus; reproductive: lateral medial preoptic nucleus; defensive: anterior hypothalamic nucleus; foraging: ventral tegmental area, along with interconnected nucleus accumbens and substantia innominata), orofacial motor control (retrorubral area), thalamocortical feedback loops (paraventricular, central medial, intermediodorsal, and medial mediodorsal nuclei; nucleus reuniens), and behavioral state control (subparaventricular zone, ventrolateral preoptic nucleus, tuberomammillary nucleus, supramammillary nucleus, lateral habenula, and raphé nuclei). This pattern of axonal projections, and what little is known of its inputs, suggest that the BSTdm is part of a striatopallidal differentiation involved in coordinating the homeostatic and behavioral responses associated thirst and salt appetite, although clearly it may relate them to other functions as well. The BSTdm generates the densest known inputs directly to the neuroendocrine system from any part of the cerebral

  6. [Morphological changes in ventricular germinal zone and neocortex of the cerebral hemispheres in human fetuses and newborns on weeks 22-40 of prenatal development].

    PubMed

    Protsenko, E V; Vasil'eva, M E; Peretiatko, L P; Malyshkina, A I

    2014-01-01

    In this study, we investigated the morphology of the ventricular germinal zone and neocortex of the cerebral hemispheres in the projection field no. 4 of the motor area in human fetuses in dynamics from week 22 to 40 of fetal development. Morphological study allowed us to clarify the following patterns of prenatal ontogeny of the human CNS. On weeks 22-27, an intensive formation of the main sulci of the first order, differentiating the brain into lobes, is observed. By weeks 28-32, the formation of all sulci of the first order is completed; and on weeks 33-37, additional sulci characteristic of an individual are formed. The spurt of gyrification of the cortex (weeks 22-27) practically coincides with the completion of neuronal differentiation and formation of the motor neocortex. The structure of the latter is characterized by a clear stratification of cytoarchitectonic layers and modular organization of neurons with their vertical orientation in cell columns (weeks 25-27). In subsequent weeks of prenatal development until birth, no significant changes in the topography and structure of the neocortex are observed. Structural rearrangement of the ventricular germinal zone on weeks 22-40 of prenatal development consists in its gradual reduction and is completed on weeks 37-40. The criteria of physiological reduction of this area are the zonal location of glioblasts and a progressive decrease in its thickness on weeks 33-37 of prenatal development.

  7. [Changes in individual profiles of cerebral hemispheric asymmetry during somatosensory stimulation due to wearing of G-suits by healthy adults and children].

    PubMed

    Iavorskiĭ, A B; Kobrin, V I; Sologubov, E G; Sinel'nikova, A N; Nemkova, S A

    1997-01-01

    Presented are results of the investigations of individual profiles of the brain interhemispheric asymmetry (IPIHA) in healthy grown-ups and children prior to, during, and immediately after somatosensory stimulation. The somatosensory stimulation was performed by one-time wearing of space g-loading suit PENGUIN and its modification ADELIE. IPIHA was studied by the main functional asymmetries including motor hand asymmetry, sensory asymmetry of the visual hemispheres, body mass center asymmetry (BMA) using a computerized stabilimeter indirectly measuring the muscle tone of contralateral extensor. Results demonstrate differences in IPIHA of grown-ups and children, persons with right- and left-hand motor asymmetry. It was shown that peculiar features of standing posture acquisition with and without visual control are original IPIHA and age dependent. Initial stability was higher in grown-ups than children and right-handed grown-ups and left-handed children. IPIHA and stability of the vertical posture can be modified even during single somatosensory stimulation. Unequal effects of the somatosensory stimulation on IPIHA in right- and left-handed subjects of varying age dictate the necessity to allow for these differences when assessing effects of the somatosensory stimulation in grown-ups and developing criteria of effective therapy of patients with CNS pathology, specifically, infantile cerebral paralysis.

  8. Hemispheric Specialization and Implications for Education of the Hearing Impaired.

    ERIC Educational Resources Information Center

    Levine, Shari

    The paper reviews research on cerebral hemispheric functioning and considers the implications for instruction of the deaf. The nature of right and left hemisphere function and communication is addressed, as are findings on cerebral asymmetry for aspects of language processing. Studies on hemispheric specialization of hearing impaired persons…

  9. [Hemispheric functional specialization and anxiety. Focus on an evaluation procedure].

    PubMed

    Perier, N; Boulenger, J P; Eustache, F; Bisserbe, J C; Lebreuilly, J; Zarifian, E

    1992-01-01

    Observations of brain-lesioned patients and experimental psychology studies have shown that the influence of the specific functioning of the two hemispheres of the brain on the regulation of emotional behaviour appears to be unequal and suggests a functional specialization of the right hemisphere for the expression and comprehension of the affective components of behaviour. However, the extension of this hypothesis to include all emotional experiences remains controversial. The observed superiority of the left hemisphere in the perception of positive emotions and the predominance of the right hemisphere in the treatment of negative emotions would appear to favour a joint and complementary participation of both cerebral hemispheres in emotional experiences. In the case of affective disorders, and particularly in anxiety symptoms, the hypothesis of a dysfunctioning of the right hemisphere is similarly questioned: while all metabolic studies corroborate this hypothesis, experimental psychological studies suggest the existence of a preferential involvement of one or the other hemisphere in relation to individual differences such as the "trait" anxiety score. Moreover, the few studies which have been undertaken with healthy volunteers raise the problem of their extrapolation to pathological situations. In view of the potential interest in the neuropsychological evaluations of subjects with different forms of pathological anxiety, we have developed an experimented with two tests aimed at evaluating the differential activity of the two hemispheres of the brain. These two tests, constructed on a "mirror-image" model from the specifications of a functional hemispheric specialization, are supposed to involve cognitive strategies pinpointing preferentially one hemisphere or the other.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Very-low-frequency oscillations of cerebral hemodynamics and blood pressure are affected by aging and cognitive load.

    PubMed

    Vermeij, Anouk; Meel-van den Abeelen, Aisha S S; Kessels, Roy P C; van Beek, Arenda H E A; Claassen, Jurgen A H R

    2014-01-15

    Spontaneous slow oscillations occur in cerebral hemodynamics and blood pressure (BP), and may reflect neurogenic, metabolic or myogenic control of the cerebral vasculature. Aging is accompanied by a degeneration of the vascular system, which may have consequences for regional cerebral blood flow and cognitive performance. This degeneration may be reflected in a reduction of spontaneous slow oscillations of cerebral hemodynamics and BP. Therefore, we aimed to establish the dependency of slow oscillations of cerebral hemodynamics and BP on the factors age and cognitive load, by using functional near-infrared spectroscopy (fNIRS). Fourteen healthy young (23-32 years) and 14 healthy older adults (64-78 years) performed a verbal n-back working-memory task. Oxygenated and deoxygenated hemoglobin concentration changes were registered by two fNIRS channels located over left and right prefrontal cortex. BP was measured in the finger by photoplethysmography. We found that very-low-frequency oscillations (0.02-0.07 Hz) and low-frequency oscillations (0.07-0.2 Hz) of cerebral hemodynamics and BP were reduced in the older adults compared to the young during task performance. In young adults, very-low-frequency oscillations of cerebral hemodynamics and BP reduced with increased cognitive load. Cognitive load did not affect low-frequency oscillations of the cerebral hemodynamics and BP. Transfer function analysis indicated that the relationship between BP and cerebral hemodynamic oscillations does not change under influence of age and cognitive load. Our results suggest aging-related changes in the microvasculature such as declined spontaneous activity in microvascular smooth muscle cells and vessel stiffness. Moreover, our results indicate that in addition to local vasoregulatory processes, systemic processes also influence cerebral hemodynamic signals. It is therefore crucial to take the factors age and BP into consideration for the analysis and interpretation of hemodynamic

  11. Factors Affecting Cerebral Oxygenation in Hemodialysis Patients: Cerebral Oxygenation Associates with pH, Hemodialysis Duration, Serum Albumin Concentration, and Diabetes Mellitus

    PubMed Central

    Ito, Kiyonori; Ookawara, Susumu; Ueda, Yuichiro; Goto, Sawako; Miyazawa, Haruhisa; Yamada, Hodaka; Kitano, Taisuke; Shindo, Mitsunobu; Kaku, Yoshio; Hirai, Keiji; Yoshida, Masashi; Hoshino, Taro; Nabata, Aoi; Mori, Honami; Yoshida, Izumi; Kakei, Masafumi; Tabei, Kaoru

    2015-01-01

    Background Patients undergoing hemodialysis (HD) often develop cerebral disease complications. Furthermore, cerebral regional saturation of oxygen (rSO2) was previously reported to be significantly lower in HD patients than in healthy subjects. We aimed to identify the factors affecting the cerebral rSO2 in HD patients. Methods Fifty-four HD patients (38 men and 16 women; mean age, 67.7 ± 1.2 years, HD duration, 6.5 ± 1.9 years) were recruited. Cerebral rSO2 was monitored at the forehead before HD using an INVOS 5100C (Covidien Japan, Tokyo, Japan). Results The rSO2 levels were significantly lower in HD patients compared with healthy controls (49.5 ± 1.7% vs. 68.9 ± 1.6%, p <0.001). Multiple regression analysis showed that cerebral rSO2 independently associated with pH (standardized coefficient: -0.35), HD duration (standardized coefficient: -0.33), and serum albumin concentration (standardized coefficient: 0.28). Furthermore, the rSO2 was significantly lower in HD patients with diabetes mellitus (DM), compared with patients without DM (46.8 ± 1.7% vs. 52.1 ± 1.8%, p <0.05). Conclusions In HD patients, cerebral rSO2 was affected by multiple factors, including pH, HD duration, and serum albumin concentration. Furthermore, this is the first report describing significantly lower levels of rSO2 in HD patients with DM than in those without DM. PMID:25706868

  12. Hemispheric Asymmetries and Cognitive Flexibility: An ERP and sLORETA Study

    ERIC Educational Resources Information Center

    Ocklenburg, Sebastian; Gunturkun, Onur; Beste, Christian

    2012-01-01

    Although functional cerebral asymmetries (FCAs) affect all cognitive domains, their modulation of the efficacy of specific executive functions is largely unexplored. In the present study, we used a lateralized version of the task switching paradigm to investigate the relevance of hemispheric asymmetries for cognitive control processes. Words were…

  13. Cognitive tasks during walking affect cerebral blood flow signal features in middle cerebral arteries and their correlation to gait characteristics.

    PubMed

    Gatouillat, Arthur; Bleton, Héloïse; VanSwearingen, Jessie; Perera, Subashan; Thompson, Scott; Smith, Traci; Sejdić, Ervin

    2015-09-26

    Gait is a complex process involving both cognitive and sensory ability and is strongly impacted by the environment. In this paper, we propose to study of the impact of a cognitive task during gait on the cerebral blood flow velocity, the blood flow signal features and the correlation of gait and blood flow features through a dual task methodology. Both cerebral blood flow velocity and gait characteristics of eleven participants with no history of brain or gait conditions were recorded using transcranial Doppler on mid-cerebral artery while on a treadmill. The cognitive task was induced by a backward counting starting from 10,000 with decrement of 7. Central blood flow velocity raw and envelope features were extracted in both time, frequency and time-scale domain; information-theoretic metrics were also extracted and statistical significances were inspected. A similar feature extraction was performed on the stride interval signal. Statistical differences between the cognitive and baseline trials, between the left and right mid-cerebral arteries signals and the impact of the antropometric variables where studied using linear mixed models. No statistical differences were found between the left and right mid-cerebral arteries flows or the baseline and cognitive state gait features, while statistical differences for specific features were measured between cognitive and baseline states. These statistical differences found between the baseline and cognitive states show that cognitive process has an impact on the cerebral activity during walking. The state was found to have an impact on the correlation between the gait and blood flow features.

  14. Left Hemispheric Imbalance and Reward Mechanisms Affect Gambling Behavior: The Contribution of the Metacognition and Cortical Brain Oscillations.

    PubMed

    Balconi, Michela; Finocchiaro, Roberta; Canavesio, Ylenia

    2015-07-01

    The present research used the Iowa Gambling Task to test the effect of the reward-sensitivity Behavioral Activation System-Reward (BAS-Reward) construct on the ability to distinguish between high- and low-risk decisions. To elucidate the individual differences that influence the decisional processes, making the strategies more or less advantageous, we considered the impact of the BAS motivational system and the frontal left and right cortical activity on subjects' decisions. More specifically, the lateralization effect, which is related to the increased activation of the left (BAS-Reward-related) hemisphere, was explored by using frequency band analysis. Specifically, behavioral responses (gain/loss options), metacognition, and delta, theta, alpha, and beta band modulation (asymmetry index) were considered. Thirty subjects were divided into high-BAS and low-BAS groups. In comparison with low-BAS, the high-BAS group showed an increased tendency to opt in favor of the immediate reward (losing strategy) instead of the long-term option (winning strategy), and members of this group were more impaired in metacognitive monitoring of their strategies and showed an increased left hemisphere activation when they responded to losing choices. A "reward bias" effect was hypothesized to act for high BAS, based on a left-hemisphere hyperactivation.

  15. Cerebral Palsy

    MedlinePlus

    Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

  16. Encephaloduroarteriosynangiosis for cerebral proliferative angiopathy with cerebral ischemia.

    PubMed

    Kono, Kenichi; Terada, Tomoaki

    2014-12-01

    Cerebral proliferative angiopathy (CPA) is a rare clinical entity. This disorder is characterized by diffuse vascular abnormalities with intermingled normal brain parenchyma, and is differentiated from classic arteriovenous malformations. The management of CPA in patients presenting with nonhemorrhagic neurological deficits due to cerebral ischemia is challenging and controversial. The authors report a case of adult CPA with cerebral ischemia in which neurological deficits were improved after encephaloduroarteriosynangiosis (EDAS). A 28-year-old man presented with epilepsy. Magnetic resonance imaging and angiography showed a diffuse vascular network (CPA) in the right hemisphere. Antiepileptic medications were administered. Four years after the initial onset of epilepsy, the patient's left-hand grip strength gradually decreased over the course of 1 year. The MRI studies showed no infarcts, but technetium-99m-labeled ethyl cysteinate dimer ((99m)Tc-ECD) SPECT studies obtained with acetazolamide challenge demonstrated hypoperfusion and severely impaired cerebrovascular reactivity over the affected hemisphere. This suggested that the patient's neurological deficits were associated with cerebral ischemia. The authors performed EDAS for cerebral ischemia, and the patient's hand grip strength gradually improved after the operation. Follow-up angiography studies obtained 7 months after the operation showed profound neovascularization through the superficial temporal artery and the middle meningeal artery. A SPECT study showed slight improvement of hypoperfusion at the focal region around the right motor area, indicating clinical improvement from the operation. The authors conclude that EDAS may be a treatment option for CPA-related hypoperfusion.

  17. Affective prosody: what do comprehension errors tell us about hemispheric lateralization of emotions, sex and aging effects, and the role of cognitive appraisal.

    PubMed

    Ross, Elliott D; Monnot, Marilee

    2011-04-01

    The Aprosodia Battery was developed to distinguish different patterns of affective-prosodic deficits in patients with left versus right brain damage by using affective utterances with incrementally reduced verbal-articulatory demands. It has also been used to assess affective-prosodic performance in various clinical groups, including patients with schizophrenia, PTSD, multiple sclerosis, alcohol abuse and Alzheimer disease and in healthy adults, as means to explore maturational-aging effects. To date, all studies using the Aprosodia Battery have yielded statistically robust results. This paper describes an extensive, quantitative error analysis using previous results from the Aprosodia Battery in patients with left and right brain damage, age-equivalent controls (old adults), and a group of young adults. This inductive analysis was performed to address three major issues in the literature: (1) sex and (2) maturational-aging effects in comprehending affective prosody and (3) differential hemispheric lateralization of emotions. We found no overall sex effects for comprehension of affective prosody. There were, however, scattered sex effects related to a particular affect, suggesting that these differences were related to cognitive appraisal rather than primary perception. Results in the brain damaged groups did not support the Valence Hypothesis of emotional lateralization but did support the Right Hemisphere Hypothesis of emotional lateralization. When comparing young versus old adults, a robust maturational-aging effect was observed in overall error rates and in the distribution of errors across affects. This effect appears to be mediated, in part, by cognitive appraisal, causing an alteration in the salience of different affective-prosodic stimuli with increasing age. In addition, the maturational-aging effects lend support for the Emotion-Type hypothesis of emotional lateralization and the "classic aging effect" that is due primarily to decline of right

  18. Cerebral White Matter Lesions and Affective Episodes Correlate in Male Individuals with Bipolar Disorder

    PubMed Central

    Birner, Armin; Seiler, Stephan; Lackner, Nina; Bengesser, Susanne A.; Queissner, Robert; Fellendorf, Frederike T.; Platzer, Martina; Ropele, Stefan; Enzinger, Christian; Schwingenschuh, Petra; Mangge, Harald; Pirpamer, Lukas; Deutschmann, Hannes; McIntyre, Roger S.; Kapfhammer, Hans-Peter; Reininghaus, Bernd; Reininghaus, Eva Z.

    2015-01-01

    Background Cerebral white matter lesions (WML) have been found in normal aging, vascular disease and several neuropsychiatric conditions. Correlations of WML with clinical parameters in BD have been described, but not with the number of affective episodes, illness duration, age of onset and Body Mass Index in a well characterized group of euthymic bipolar adults. Herein, we aimed to evaluate the associations between bipolar course of illness parameters and WML measured with volumetric analysis. Methods In a cross-sectional study 100 euthymic individuals with BD as well as 54 healthy controls (HC) were enrolled to undergo brain magnetic resonance imaging using 3T including a FLAIR sequence for volumetric assessment of WML-load using FSL-software. Additionally, clinical characteristics and psychometric measures including Structured Clinical Interview according to DSM-IV, Hamilton-Depression, Young Mania Rating Scale and Beck’s Depression Inventory were evaluated. Results Individuals with BD had significantly more (F = 3.968, p < .05) WML (Mdn = 3710mm3; IQR = 2961mm3) than HC (Mdn = 2185mm3; IQR = 1665mm3). BD men (Mdn = 4095mm3; IQR = 3295mm3) and BD women (Mdn = 3032mm3; IQR = 2816mm3) did not significantly differ as to the WML-load or the number and type of risk factors for WML. However, in men only, the number of manic/hypomanic episodes (r = 0.72; p < .001) as well as depressive episodes (r = 0.51; p < .001) correlated positively with WML-load. Conclusions WML-load strongly correlated with the number of manic episodes in male BD patients, suggesting that men might be more vulnerable to mania in the context of cerebral white matter changes. PMID:26252714

  19. Reduced short term adaptation to robot generated dynamic environment in children affected by Cerebral Palsy

    PubMed Central

    2011-01-01

    Background It is known that healthy adults can quickly adapt to a novel dynamic environment, generated by a robotic manipulandum as a structured disturbing force field. We suggest that it may be of clinical interest to evaluate to which extent this kind of motor learning capability is impaired in children affected by cerebal palsy. Methods We adapted the protocol already used with adults, which employs a velocity dependant viscous field, and compared the performance of a group of subjects affected by Cerebral Palsy (CP group, 7 subjects) with a Control group of unimpaired age-matched children. The protocol included a familiarization phase (FA), during which no force was applied, a force field adaptation phase (CF), and a wash-out phase (WO) in which the field was removed. During the CF phase the field was shut down in a number of randomly selected "catch" trials, which were used in order to evaluate the "learning index" for each single subject and the two groups. Lateral deviation, speed and acceleration peaks and average speed were evaluated for each trajectory; a directional analysis was performed in order to inspect the role of the limb's inertial anisotropy in the different experimental phases. Results During the FA phase the movements of the CP subjects were more curved, displaying greater and variable directional error; over the course of the CF phase both groups showed a decreasing trend in the lateral error and an after-effect at the beginning of the wash-out, but the CP group had a non significant adaptation rate and a lower learning index, suggesting that CP subjects have reduced ability to learn to compensate external force. Moreover, a directional analysis of trajectories confirms that the control group is able to better predict the force field by tuning the kinematic features of the movements along different directions in order to account for the inertial anisotropy of arm. Conclusions Spatial abnormalities in children affected by cerebral palsy may be

  20. Seat surface inclination may affect postural stability during Boccia ball throwing in children with cerebral palsy.

    PubMed

    Tsai, Yung-Shen; Yu, Yi-Chen; Huang, Po-Chang; Cheng, Hsin-Yi Kathy

    2014-12-01

    The aim of the study was to examine how seat surface inclination affects Boccia ball throwing movement and postural stability among children with cerebral palsy (CP). Twelve children with bilateral spastic CP (3 with gross motor function classification system Level I, 5 with Level II, and 4 with Level III) participated in this study. All participants underwent pediatric reach tests and ball throwing performance analyses while seated on 15° anterior- or posterior-inclined, and horizontal surfaces. An electromagnetic motion analysis system was synchronized with a force plate to assess throwing motion and postural stability. The results of the pediatric reach test (p = 0.026), the amplitude of elbow movement (p = 0.036), peak vertical ground reaction force (PVGRF) (p < 0.001), and movement range of the center of pressure (COP) (p < 0.020) were significantly affected by seat inclination during throwing. Post hoc comparisons showed that anterior inclination allowed greater amplitude of elbow movement and PVGRF, and less COP movement range compared with the other inclines. Posterior inclination yielded less reaching distance and PVGRF, and greater COP movement range compared with the other inclines. The anterior-inclined seat yielded superior postural stability for throwing Boccia balls among children with bilateral spastic CP, whereas the posterior-inclined seat caused difficulty.

  1. Continuous theta burst stimulation (cTBS) on left cerebellar hemisphere affects mental rotation tasks during music listening.

    PubMed

    Picazio, Silvia; Oliveri, Massimiliano; Koch, Giacomo; Caltagirone, Carlo; Petrosini, Laura

    2013-01-01

    Converging evidence suggests an association between spatial and music domains. A cerebellar role in music-related information processing as well as in spatial-temporal tasks has been documented. Here, we investigated the cerebellar role in the association between spatial and musical domains, by testing performances in embodied (EMR) or abstract (AMR) mental rotation tasks of subjects listening Mozart Sonata K.448, which is reported to improve spatial-temporal reasoning, in the presence or in the absence of continuous theta burst stimulation (cTBS) of the left cerebellar hemisphere. In the absence of cerebellar cTBS, music listening did not influence either MR task, thus not revealing a "Mozart Effect". Cerebellar cTBS applied before musical listening made subjects faster (P = 0.005) and less accurate (P = 0.005) in performing the EMR but not the AMR task. Thus, cerebellar inhibition by TBS unmasked the effect of musical listening on motor imagery. These data support a coupling between music listening and sensory-motor integration in cerebellar networks for embodied representations.

  2. Right Hemisphere Brain Damage

    MedlinePlus

    ... Language and Swallowing / Disorders and Diseases Right Hemisphere Brain Damage [ en Español ] What is right hemisphere brain ... right hemisphere brain damage ? What is right hemisphere brain damage? Right hemisphere brain damage (RHD) is damage ...

  3. Beyond hemispheric dominance: brain regions underlying the joint lateralization of language and arithmetic to the left hemisphere.

    PubMed

    Pinel, Philippe; Dehaene, Stanislas

    2010-01-01

    Language and arithmetic are both lateralized to the left hemisphere in the majority of right-handed adults. Yet, does this similar lateralization reflect a single overall constraint of brain organization, such an overall "dominance" of the left hemisphere for all linguistic and symbolic operations? Is it related to the lateralization of specific cerebral subregions? Or is it merely coincidental? To shed light on this issue, we performed a "colateralization analysis" over 209 healthy subjects: We investigated whether normal variations in the degree of left hemispheric asymmetry in areas involved in sentence listening and reading are mirrored in the asymmetry of areas involved in mental arithmetic. Within the language network, a region-of-interest analysis disclosed partially dissociated patterns of lateralization, inconsistent with an overall "dominance" model. Only two of these areas presented a lateralization during sentence listening and reading which correlated strongly with the lateralization of two regions active during calculation. Specifically, the profile of asymmetry in the posterior superior temporal sulcus during sentence processing covaried with the asymmetry of calculation-induced activation in the intraparietal sulcus, and a similar colateralization linked the middle frontal gyrus with the superior posterior parietal lobule. Given recent neuroimaging results suggesting a late emergence of hemispheric asymmetries for symbolic arithmetic during childhood, we speculate that these colateralizations might constitute developmental traces of how the acquisition of linguistic symbols affects the cerebral organization of the arithmetic network.

  4. Shift-back of right into left hemisphere language dominance after control of epileptic seizures: evidence for epilepsy driven functional cerebral organization.

    PubMed

    Helmstaedter, C; Fritz, N E; González Pérez, P A; Elger, C E; Weber, B

    2006-08-01

    Atypical, i.e. right hemisphere language dominance is frequently observed in early onset left hemisphere epilepsies. In left mesial temporal lobe epilepsy, where eloquent cortex is not directly involved, it is a matter of debate, to which degree atypical language dominance is driven not only by morphological lesions but also by epileptic dysfunction, and whether atypical dominance is hardwired or not. Taking this as the background this study evaluated the hypothesis that epilepsy driven atypical dominancy might be reversible when seizures are successfully controlled. This was evaluated in patients with left mesial temporal lobe epilepsy, who were atypically language dominant by means of language fMRI before surgery, and became seizure free after left selective amygdalo-hippocampectomy. Three out of 53 consecutive atypically dominant patients with chronic epilepsy fulfilled these criteria. Postoperative follow-up language fMRI indicated reversal of right into left dominance in one patient going along with unexpected losses in verbal memory performance. The two other patients experienced unchanged or even enhancement of the pre-existing dominance pattern, going along with consistent postoperative performance changes in cognition. The data thus provide supporting evidence that atypical language dominance can indeed be functionally driven and moreover that in at least some patients, right hemispheric language can shift-back to the left hemisphere when the driving factor, i.e. seizures, becomes successfully controlled. The results have clinical implications for outcome prediction after brain surgery in atypically dominant patients with epilepsy. However, further research in larger groups of atypically dominant patients is required to identify the conditions under which atypical dominance becomes hardwired and when not.

  5. Hemispheric Amphigory.

    ERIC Educational Resources Information Center

    Youngblood, Michael

    1981-01-01

    Reviewing some empirical studies on brain hemisphere functions, the author concludes that though the brain is lateralized for specific tasks, this fact has no necessary bearing on educational methodology. He asserts that we do not yet know enough to label and teach art as a "right brain" activity. (Author/SJL)

  6. Hemisphericity Research: An Overview with Some Implications for Problem Solving.

    ERIC Educational Resources Information Center

    Myers, John T.

    1982-01-01

    Research on cerebral hemisphericity and lateral dominance is reviewed, and relationships between right and left hemispheric modes of information processing as well as problem solving techniques are discussed. Conclusions focus mainly on need for educators to know information processing differences of the two hemispheres to teach children problem…

  7. Reorganization of the Cerebro-Cerebellar Network of Language Production in Patients with Congenital Left-Hemispheric Brain Lesions

    ERIC Educational Resources Information Center

    Lidzba, K.; Wilke, M.; Staudt, M.; Krageloh-Mann, I.; Grodd, W.

    2008-01-01

    Patients with congenital lesions of the left cerebral hemisphere may reorganize language functions into the right hemisphere. In these patients, language production is represented homotopically to the left-hemispheric language areas. We studied cerebellar activation in five patients with congenital lesions of the left cerebral hemisphere to assess…

  8. Brown propolis attenuates cerebral ischemia-induced oxidative damage via affecting antioxidant enzyme system in mice.

    PubMed

    Bazmandegan, Gholamreza; Boroushaki, Mohammad Taher; Shamsizadeh, Ali; Ayoobi, Fatemeh; Hakimizadeh, Elham; Allahtavakoli, Mohammad

    2017-01-01

    Oxidative stress plays a critical role in ischemic brain injury. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) are the enzymes underlying the endogenous antioxidant mechanisms affected by stroke and are considered as oxidative stress biomarkers. Brown propolis (BP) is a bioactive natural product with a set of biological activities that in turn may differ depending on the area from which the substance is originated. The aim of this study was to investigate the effect of water-extracted brown propolis (WEBPs), from two regions of Iran, against cerebral ischemia-induced oxidative injury in a mouse model of stroke. Experimentally, the chemical characterization and total polyphenol content were determined using GC/MS and Folin-Ciocalteu assay respectively. Seventy-two adult male mice were randomly divided into the surgical sham group, control group (treated with vehicle), and four groups of WEBPs-treated animals. The WEBPs were administered at the doses of 100 and 200mg/kg IP, during four different time points. Oxidative stress biomarkers (SOD and GPx activity, SOD/GPx ratio), lipid peroxidation (LPO) index (malondialdehyde content) and infarct volume were measured 48h post stroke. Behavioral tests were evaluated 24 and 48h after stroke. WEBPs treatment resulted in significant restoration of antioxidant enzymes activity and a subsequent decrease in LPO as well as the infarct volume compared to the control group. Sensory-motor impairment and neurological deficits were improved significantly as well. These results indicate that Iranian BP confers neuroprotection on the stroke-induced neuronal damage via an antioxidant mechanism which seems to be mediated by the endogenous antioxidant system.

  9. Resource Allocation in Cerebral Specialization.

    DTIC Science & Technology

    1980-01-01

    of this multiple-resources view. EXTENSION OF THE THEORY TO THE TWO CEREBRAL HEMISPHERES Since the anatomical division of the brain invites...performance differences between the hemispheres (e.g., right-handed males with no familial history of left- handedness who use a normal rather than an...G. Beaumont (Eds.), Hemisphere function in the human rain.. New York: Halstead Press, 1974. Kinsbourne, M. The cerebral basis of lateral asymmetries

  10. Increased cerebral blood flow during hypercapnia is not affected by lesion of the nucleus locus ceruleus

    SciTech Connect

    Harik, S.I.; Prado, R.; Busto, R.; Ginsberg, M.D.

    1986-11-01

    To test the hypothesis that the putative noradrenergic innervation of intraparenchymal cerebral blood vessels from the nucleus locus ceruleus mediates the vasodilatory response to hypercapnia, regional cerebral blood flow was measured by iodo-(/sup 14/C)antipyrine autoradiography in awake and restrained rats with unilateral 6-hydroxydopamine lesion of the nucleus locus ceruleus and in unlesioned control rats. Hypercapnia, induced by the inhalation of 5% or 8% CO/sub 2/ in air for 8 minutes caused a 2 to 5-fold increase in regional cerebral blood flow. However, despite a marked reduction of about 90% in cortical norepinephrine levels ipsilateral to the lesion, blood flow to the frontal and parietal cortex, hippocampus, striatum and cerebellum increased to the same extent in ipsilateral and contralateral regions. Thus, lesion of the locus ceruleus and the resultant depletion of endogenous cortical and hippocampal norepinephrine, does not influence the cerebrovascular response to hypercapnia.

  11. MicroRNAs affect BCL-2 family proteins in the setting of cerebral ischemia.

    PubMed

    Ouyang, Yi-Bing; Giffard, Rona G

    2014-11-01

    The BCL-2 family is centrally involved in the mechanism of cell death after cerebral ischemia. It is well known that the proteins of the BCL-2 family are key regulators of apoptosis through controlling mitochondrial outer membrane permeabilization. Recent findings suggest that many BCL-2 family members are also directly involved in controlling transmission of Ca(2+) from the endoplasmic reticulum (ER) to mitochondria through a specialization called the mitochondria-associated ER membrane (MAM). Increasing evidence supports the involvement of microRNAs (miRNAs), some of them targeting BCL-2 family proteins, in the regulation of cerebral ischemia. In this mini-review, after highlighting current knowledge about the multiple functions of BCL-2 family proteins and summarizing their relationship to outcome from cerebral ischemia, we focus on the regulation of BCL-2 family proteins by miRNAs, especially miR-29 which targets multiple BCL-2 family proteins.

  12. Cerebral Hemodynamics and Vascular Reactivity in Mild and Severe Ischemic Rodent Middle Cerebral Artery Occlusion Stroke Models

    PubMed Central

    Sim, Jeongeun; Jo, Areum; Kang, Bok-Man; Lee, Sohee; Bang, Oh Young; Heo, Chaejeong; Jhon, Gil-Ja; Lee, Youngmi

    2016-01-01

    Ischemia can cause decreased cerebral neurovascular coupling, leading to a failure in the autoregulation of cerebral blood flow. This study aims to investigate the effect of varying degrees of ischemia on cerebral hemodynamic reactivity using in vivo real-time optical imaging. We utilized direct cortical stimulation to elicit hyper-excitable neuronal activation, which leads to induced hemodynamic changes in both the normal and middle cerebral artery occlusion (MCAO) ischemic stroke groups. Hemodynamic measurements from optical imaging accurately predict the severity of occlusion in mild and severe MCAO animals. There is neither an increase in cerebral blood volume nor in vessel reactivity in the ipsilateral hemisphere (I.H) of animals with severe MCAO. The pial artery in the contralateral hemisphere (C.H) of the severe MCAO group reacted more slowly than both hemispheres in the normal and mild MCAO groups. In addition, the arterial reactivity of the I.H in the mild MCAO animals was faster than the normal animals. Furthermore, artery reactivity is tightly correlated with histological and behavioral results in the MCAO ischemic group. Thus, in vivo optical imaging may offer a simple and useful tool to assess the degree of ischemia and to understand how cerebral hemodynamics and vascular reactivity are affected by ischemia. PMID:27358581

  13. Does Surgical Management of the Hand in Children with Spastic Unilateral Cerebral Palsy Affect Functional Outcome?

    ERIC Educational Resources Information Center

    van Munster, Judith C.; Maathuis, Karel G. B.; Haga, Nienke; Verheij, Nienke P.; Nicolai, Jean-Philippe A.; Hadders-Algra, Mijna

    2007-01-01

    The aim of this review was to examine the literature on the effects of surgery of the spastic hand in children with cerebral palsy on functional outcome and muscle coordination. We performed a search of the relevant literature in Medline, Embase, and Biological Abstracts from 1966 to June 2006. The search resulted in eight studies on the effect of…

  14. Do GSM 900MHz signals affect cerebral blood circulation? A near-infrared spectrophotometry study

    NASA Astrophysics Data System (ADS)

    Wolf, Martin; Haensse, Daniel; Morren, Geert; Froehlich, Juerg

    2006-06-01

    Effects of GSM 900MHz signals (EMF) typical for a handheld mobile phone on the cerebral blood circulation were investigated using near-infrared spectrophotometry (NIRS) in a three armed (12W/kg, 1.2W/kg, sham), double blind, randomized crossover trial in 16 healthy volunteers. During exposure we observed borderline significant short term responses of oxyhemoglobin and deoxyhemoglobin concentration, which correspond to a decrease of cerebral blood flow and volume and were smaller than regular physiological changes. Due to the relatively high number of statistical tests, these responses may be spurious and require further studies. There was no detectable dose-response relation or long term response within 20min. The detection limit was a fraction of the regular physiological changes elicited by functional activation. Compared to previous studies using PET, NIRS provides a much higher time resolution, which allowed investigating the short term effects efficiently, noninvasively, without the use of radioactive tracers and with high sensitivity.

  15. Cerebral endothelial expression of Robo1 affects brain infiltration of polymorphonuclear neutrophils during mouse stroke recovery.

    PubMed

    Gangaraju, Sandhya; Sultan, Khadeejah; Whitehead, Shawn N; Nilchi, Ladan; Slinn, Jacqueline; Li, Xuesheng; Hou, Sheng T

    2013-06-01

    Increased brain infiltration of polymorphonuclear neutrophils (PMNs) occurs early after stroke and is important in eliciting brain inflammatory response during stroke recovery. In order to understand the molecular mechanism of PMN entry, we investigated the expression and requirement for Slit1, a chemorepulsive guidance cue, and its cognate receptor, Robo1, in a long-term recovery mouse model of cerebral ischemia. The expression levels of Robo1 were significantly decreased bilaterally at 24h following reperfusion. Robo1 expression levels remained suppressed in the ipsilateral cortex until 28d post MCAO-reperfusion, while the levels of Robo1 in the contralateral cortex recovered to the level of sham-operated mouse by 7d reperfusion. Circulating PMNs express high levels of Slit1, but not Robo1. Influx of PMNs into the ischemic core area occurred early (24h) after cerebral ischemia, when endothelial Robo1 expression was significantly reduced in the ischemic brain, indicating that Robo1 may form a repulsive barrier to PMN entry into the brain parenchyma. Indeed, blocking Slit1 on PMNs in a transwell migration assay in combination with an antibody blocking of Robo1 on human umbilical vein endothelial cells (HUVEC) significantly increased PMN transmigration during oxygen glucose deprivation, an in vitro model of ischemia. Collectively, in the normal brain, the presence of Slit1 on PMNs, and Robo1 on cerebral endothelial cells, generated a repulsive force to prevent the infiltration of PMNs into the brain. During stroke recovery, a transient reduction in Robo1 expression on the cerebral endothelial cells allowed the uncontrolled infiltration of Slit1-expressing PMNs into the brain causing inflammatory reactions.

  16. Multiple medullary venous malformations decreasing cerebral blood flow: Case report

    SciTech Connect

    Tomura, N.; Inugami, A.; Uemura, K.; Hadeishi, H.; Yasui, N. )

    1991-02-01

    A rare case of multiple medullary venous malformations in the right cerebral hemisphere is reported. The literature review yielded only one case of multiple medullary venous malformations. Computed tomography scan showed multiple calcified lesions with linear contrast enhancement representing abnormal dilated vessels and mild atrophic change of the right cerebral hemisphere. Single-photon emission computed tomography using N-isopropyl-p-({sup 123}I) iodoamphetamine demonstrated decreased cerebral blood flow in the right cerebral hemisphere.

  17. Cerebral salt wasting syndrome in a patient affected of spontaneous frontoparietal subdural haematoma.

    PubMed

    Cerdá-Esteve, Mariaina; Badia, Mariona; Trujillano, Javier; Vilanova, Cecília; Maravall, Javier; Mauricio, Dídac

    2009-01-01

    Ever since cerebral salt wasting syndrome (CSW) was first described in 1950, there have been debates over its existence and whether it has an important place in the differential diagnosis of hyponatraemia. We report the case of a neurosurgical patient with sustained hyponatraemia and abnormally high sodium loss in the urine, with signs of fluid volume depletion. Hyponatraemia was not corrected after an intravenous infusion of saline solution. Stable concentrations of blood sodium above 130 mmol/l were achieved with the administration of 100 mg of hydrocortisone daily, with an ensuing reduction in sodium elimination through the urine.

  18. Positron emission tomography in the newborn: extensive impairment of regional cerebral blood flow with intraventricular hemorrhage and hemorrhagic intracerebral involvement

    SciTech Connect

    Volpe, J.J.; Herscovitch, P.; Perlman, J.M.; Raichle, M.E.

    1983-11-01

    Positron emission tomography (PET) now provides the capability of measuring regional cerebral blood flow with high resolution and little risk. In this study, we utilized PET in six premature infants (920 to 1,200 g) with major intraventricular hemorrhage and hemorrhagic intracerebral involvement to measure regional cerebral blood flow during the acute period (5 to 17 days of age). Cerebral blood flow was determined after intravenous injection of H/sub 2/O, labeled with the positron-emitting isotope, /sup 15/O. Findings were similar and dramatic in all six infants. In the area of hemorrhagic intracerebral involvement, little or no cerebral blood flow was detected. However, in addition, surprisingly, a marked two- to fourfold reduction in cerebral blood flow was observed throughout the affected hemisphere, well posterior and lateral to the intracerebral hematoma, including cerebral white matter and, to a lesser extent, frontal, temporal, and parietal cortex. In the one infant studied a second time, ie, at 3 months of age, the extent and severity of the decreased cerebral blood flows in the affected hemisphere were similar to those observed on the study during the neonatal period. At the three autopsies, the affected left hemisphere showed extensive infarction, corroborating the PET scans. These observations, the first demonstration of the use of PET in the determination of regional cerebral blood flow in the newborn, show marked impairments in regional cerebral blood flow in the hemisphere containing an apparently restricted intracerebral hematoma, indicating that the hemorrhagic intracerebral involvement is only a component of a much larger lesion, ischemic in basic nature, ie, an infarction. This large ischemic lesion explains the poor neurologic outcome in infants with intraventricular hemorrhage and hemorrhagic intracerebral involvement.

  19. Anomaly Detection in the Right Hemisphere: The Influence of Visuospatial Factors

    ERIC Educational Resources Information Center

    Smith, Stephen D.; Dixon, Michael J.; Tays, William J.; Bulman-Fleming, M. Barbara

    2004-01-01

    Previous research with both brain-damaged and neurologically intact populations has demonstrated that the right cerebral hemisphere (RH) is superior to the left cerebral hemisphere (LH) at detecting anomalies (or incongruities) in objects (Ramachandran, 1995; Smith, Tays, Dixon, & Bulman-Fleming, 2002). The current research assesses whether the RH…

  20. Toll Like Receptor 4 Affects the Cerebral Biochemical Changes Induced by MPTP Treatment.

    PubMed

    Conte, Carmela; Roscini, Luca; Sardella, Roccaldo; Mariucci, Giuseppina; Scorzoni, Stefania; Beccari, Tommaso; Corte, Laura

    2017-02-01

    The etiology and pathogenesis of Parkinson's disease (PD) are still unclear. However, multiple lines of evidence suggest a critical role of the toll like receptor 4 (TLR4) in inflammatory response and neuronal death. Neuroinflammation may be associated with the misfolding and aggregation of proteins accompanied by a change in their secondary structure. Recent findings also suggest that biochemical perturbations in cerebral lipid content could contribute to the pathogenesis of central nervous system (CNS) disorders, including PD. Thus, it is of great importance to determine the biochemical changes that occur in PD. In this respect, Fourier Transform Infrared (FTIR) spectroscopy represents a useful tool to detect molecular alterations in biological systems in response to stress stimuli. By relying upon FTIR approach, this study was designed to elucidate the potential role of TLR4 in biochemical changes induced by methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxin in a mouse model of PD. The analysis of the FTIR spectra was performed in different brain regions of both wild type (WT) and toll like receptor 4-deficient (TLR4(-/-)) mice. It revealed that each brain region exhibited a characteristic molecular fingerprint at baseline, with no significant differences between genotypes. Conversely, WT and TLR4(-/-) mice showed differential biochemical response to MPTP toxicity, principally related to lipid and protein composition. These differences appeared to be characteristic for each brain area. Furthermore, the present study showed that WT mice resulted more vulnerable than TLR4(-/-) animals to striatal dopamine (DA) depletion following MPTP treatment. These results support the hypothesis of a possible involvement of TLR4 in biochemical changes occurring in neurodegeneration.

  1. Do Sustained Lung Inflations during Neonatal Resuscitation Affect Cerebral Blood Volume in Preterm Infants? A Randomized Controlled Pilot Study

    PubMed Central

    Schwaberger, Bernhard; Pichler, Gerhard; Avian, Alexander; Binder-Heschl, Corinna; Baik, Nariae; Urlesberger, Berndt

    2015-01-01

    Background Sustained lung inflations (SLI) during neonatal resuscitation may promote alveolar recruitment in preterm infants. While most of the studies focus on respiratory outcome, the impact of SLI on the brain hasn’t been investigated yet. Objective Do SLI affect cerebral blood volume (CBV) in preterm infants? Methods Preterm infants of gestation 28 weeks 0 days to 33 weeks 6 days with requirement for respiratory support (RS) were included in this randomized controlled pilot trial. Within the first 15 minutes after birth near-infrared spectroscopy (NIRS) measurements using ‘NIRO-200-NX’ (Hamamatsu, Japan) were performed to evaluate changes in CBV and cerebral tissue oxygenation. Two groups were compared based on RS: In SLI group RS was given by applying 1–3 SLI (30 cmH2O for 15 s) continued by respiratory standard care. Control group received respiratory standard care only. Results 40 infants (20 in each group) with mean gestational age of 32 weeks one day (±2 days) and birth weight of 1707 (±470) g were included. In the control group ΔCBV was significantly decreasing, whereas in SLI group ΔCBV showed similar values during the whole period of 15 minutes. Comparing both groups within the first 15 minutes ΔCBV showed a tendency toward different overall courses (p = 0.051). Conclusion This is the first study demonstrating an impact of SLI on CBV. Further studies are warranted including reconfirmation of the present findings in infants with lower gestational age. Future investigations on SLI should not only focus on respiratory outcome but also on the consequences on the developing brain. Trial Registration German Clinical Trials Register DRKS00005161 https://drks-neu.uniklinik-freiburg.de/drks_web/setLocale_EN.do PMID:26406467

  2. Hemispheric specialization in dogs for processing different acoustic stimuli.

    PubMed

    Siniscalchi, Marcello; Quaranta, Angelo; Rogers, Lesley J

    2008-01-01

    Considerable experimental evidence shows that functional cerebral asymmetries are widespread in animals. Activity of the right cerebral hemisphere has been associated with responses to novel stimuli and the expression of intense emotions, such as aggression, escape behaviour and fear. The left hemisphere uses learned patterns and responds to familiar stimuli. Although such lateralization has been studied mainly for visual responses, there is evidence in primates that auditory perception is lateralized and that vocal communication depends on differential processing by the hemispheres. The aim of the present work was to investigate whether dogs use different hemispheres to process different acoustic stimuli by presenting them with playbacks of a thunderstorm and their species-typical vocalizations. The results revealed that dogs usually process their species-typical vocalizations using the left hemisphere and the thunderstorm sounds using the right hemisphere. Nevertheless, conspecific vocalizations are not always processed by the left hemisphere, since the right hemisphere is used for processing vocalizations when they elicit intense emotion, including fear. These findings suggest that the specialisation of the left hemisphere for intraspecific communication is more ancient that previously thought, and so is specialisation of the right hemisphere for intense emotions.

  3. Restricted Arm Swing Affects Gait Stability and Increased Walking Speed Alters Trunk Movements in Children with Cerebral Palsy

    PubMed Central

    Delabastita, Tijs; Desloovere, Kaat; Meyns, Pieter

    2016-01-01

    Observational research suggests that in children with cerebral palsy, the altered arm swing is linked to instability during walking. Therefore, the current study investigates whether children with cerebral palsy use their arms more than typically developing children, to enhance gait stability. Evidence also suggests an influence of walking speed on gait stability. Moreover, previous research highlighted a link between walking speed and arm swing. Hence, the experiment aimed to explore differences between typically developing children and children with cerebral palsy taking into account the combined influence of restricting arm swing and increasing walking speed on gait stability. Spatiotemporal gait characteristics, trunk movement parameters and margins of stability were obtained using three dimensional gait analysis to assess gait stability of 26 children with cerebral palsy and 24 typically developing children. Four walking conditions were evaluated: (i) free arm swing and preferred walking speed; (ii) restricted arm swing and preferred walking speed; (iii) free arm swing and high walking speed; and (iv) restricted arm swing and high walking speed. Double support time and trunk acceleration variability increased more when arm swing was restricted in children with bilateral cerebral palsy compared to typically developing children and children with unilateral cerebral palsy. Trunk sway velocity increased more when walking speed was increased in children with unilateral cerebral palsy compared to children with bilateral cerebral palsy and typically developing children and in children with bilateral cerebral palsy compared to typically developing children. Trunk sway velocity increased more when both arm swing was restricted and walking speed was increased in children with bilateral cerebral palsy compared to typically developing children. It is proposed that facilitating arm swing during gait rehabilitation can improve gait stability and decrease trunk movements in

  4. Restricted Arm Swing Affects Gait Stability and Increased Walking Speed Alters Trunk Movements in Children with Cerebral Palsy.

    PubMed

    Delabastita, Tijs; Desloovere, Kaat; Meyns, Pieter

    2016-01-01

    Observational research suggests that in children with cerebral palsy, the altered arm swing is linked to instability during walking. Therefore, the current study investigates whether children with cerebral palsy use their arms more than typically developing children, to enhance gait stability. Evidence also suggests an influence of walking speed on gait stability. Moreover, previous research highlighted a link between walking speed and arm swing. Hence, the experiment aimed to explore differences between typically developing children and children with cerebral palsy taking into account the combined influence of restricting arm swing and increasing walking speed on gait stability. Spatiotemporal gait characteristics, trunk movement parameters and margins of stability were obtained using three dimensional gait analysis to assess gait stability of 26 children with cerebral palsy and 24 typically developing children. Four walking conditions were evaluated: (i) free arm swing and preferred walking speed; (ii) restricted arm swing and preferred walking speed; (iii) free arm swing and high walking speed; and (iv) restricted arm swing and high walking speed. Double support time and trunk acceleration variability increased more when arm swing was restricted in children with bilateral cerebral palsy compared to typically developing children and children with unilateral cerebral palsy. Trunk sway velocity increased more when walking speed was increased in children with unilateral cerebral palsy compared to children with bilateral cerebral palsy and typically developing children and in children with bilateral cerebral palsy compared to typically developing children. Trunk sway velocity increased more when both arm swing was restricted and walking speed was increased in children with bilateral cerebral palsy compared to typically developing children. It is proposed that facilitating arm swing during gait rehabilitation can improve gait stability and decrease trunk movements in

  5. Plantarflexor training affects propulsive force generation during gait in children with spastic hemiplegic cerebral palsy: a pilot study

    PubMed Central

    Ishihara, Misako; Higuchi, Yumi; Yonetsu, Ryo; Kitajima, Hiromi

    2015-01-01

    [Purpose] The purpose of this preliminary study was to assess the trade-off relationship between the hip and ankle joints after plantarflexor training in children with spastic hemiplegic cerebral palsy (CP). [Subjects and Methods] Three boys aged 9, 10, and 13 years with spastic hemiplegic CP participated in the study. Gait analysis was performed using a three-dimensional motion analysis device and a floor reaction force detection device before and after plantarflexor training. Data on gait speed and stride length for both sides were collected. Peak hip and ankle powers in the sagittal plane and ankle-to-hip power ratio (A2/H3 ratio) were calculated. Plantarflexor training comprised heel raises and exercise band resistance at the participant’s home (3 times/week for 12 weeks). [Results] The A2/H3 ratio increased significantly on both sides in two of three subjects after training. Peak A2 power increased significantly on both sides in subject 3 and on the affected side of subject 2. Peak H3 power decreased significantly on the non-affected side of subjects 1 and 2. [Conclusion] This study confirmed that two of three subjects demonstrated a trade-off relationship between the hip and ankle joints during gait after plantarflexor training. PMID:26157201

  6. The Representation of Discourse in the Two Hemispheres: An Individual Differences Investigation

    ERIC Educational Resources Information Center

    Prat, Chantel S.; Long, Debra L.; Baynes, Kathleen

    2007-01-01

    Two experiments were conducted to investigate discourse representation in the two cerebral hemispheres as a function of reading skill. We used a lateralized visual-field procedure to compare left hemisphere (LH) and right hemisphere (RH) sensitivity to different discourse relations in readers with varying skill levels. In Experiment 1, we…

  7. Hemispheric Division of Function Is the Result of Independent Probabilistic Biases

    ERIC Educational Resources Information Center

    Whitehouse, Andrew J. O.; Bishop, Dorothy V. M.

    2009-01-01

    Verbal and visuospatial abilities are typically subserved by different cerebral hemispheres: the left hemisphere for the former and the right hemisphere for the latter. However little is known of the origin of this division of function. Causal theories propose that functional asymmetry is an obligatory pattern of organisation, while statistical…

  8. Alteration of the Intra- and Cross- Hemisphere Posterior Default Mode Network in Frontal Lobe Glioma Patients

    PubMed Central

    Zhang, Haosu; Shi, Yonghong; Yao, Chengjun; Tang, Weijun; Yao, Demin; Zhang, Chenxi; Wang, Manning; Wu, Jinsong; Song, Zhijian

    2016-01-01

    Patients with frontal lobe gliomas often experience neurocognitive dysfunctions before surgery, which affects the default mode network (DMN) to different degrees. This study quantitatively analyzed this effect from the perspective of cerebral hemispheric functional connectivity (FC). We collected resting-state fMRI data from 20 frontal lobe glioma patients before treatment and 20 healthy controls. All of the patients and controls were right-handed. After pre-processing the images, FC maps were built from the seed defined in the left or right posterior cingulate cortex (PCC) to the target regions determined in the left or right temporal-parietal junction (TPJ), respectively. The intra- and cross-group statistical calculations of FC strength were compared. The conclusions were as follows: (1) the intra-hemisphere FC strength values between the PCC and TPJ on the left and right were decreased in patients compared with controls; and (2) the correlation coefficients between the FC pairs in the patients were increased compared with the corresponding controls. When all of the patients were grouped by their tumor’s hemispheric location, (3) the FC of the subgroups showed that the dominant hemisphere was vulnerable to glioma, and (4) the FC in the dominant hemisphere showed a significant correlation with WHO grade. PMID:27248706

  9. Arbitrary visuomotor mapping in the grip-lift task: dissociation of performance deficits in right and left middle cerebral artery stroke.

    PubMed

    Bensmail, D; Sarfeld, A-S; Ameli, M; Fink, G R; Nowak, D A

    2012-05-17

    The ability to rapidly establish a memory link between arbitrary sensory cues and goal-directed movements is part of our daily motor repertoire. It is unknown if this ability is affected by middle cerebral artery stroke. Eighteen right-handed subjects with a first unilateral middle cerebral artery stroke were studied while performing a precision grip to lift objects of different weights. In a "no cue" condition, a noninformative neutral visual stimulus was presented before each lift, thereby not allowing any judgment about the object weight. In a "cue" condition arbitrary color cues provided advance information about the weight to be lifted in the subsequent trial. Subjects performed both conditions with either hand. During "no cue" trials subjects scaled their grip force according to the weight of the preceding lift, irrespective of the hand performing the lift or the hemisphere affected. The presentation of color cues allowed patients with right hemispheric stroke, but not those with left hemispheric stroke, to scale their grip force according to the weight in the upcoming lift when lifting the weight with the unaffected hand. Color cues did not allow for a predictive scaling of grip force according to the weight of the object to be lifted when lifting with the affected hand, irrespective of the affected hemisphere. These data imply that the ability of visuomotor mapping in the grip-lift task is selectively impaired in the affected hand after right middle cerebral artery stroke, but in both hands after left middle cerebral artery stroke.

  10. Discourse functions and hemispheric asymmetry.

    PubMed

    Osiejuk, E

    1993-01-01

    This paper presents a review of the main results of an application of discourse analysis in aphasics with the left hemisphere damages and in the right hemisphere damaged (RHD) patients. Research findings indicate that aphasics have marked deficits on the level of microstructure, especially cohesion of discourse, whereas the coherence and superstructure of their texts are relatively well preserved. RHD patients show difficulties at the microstructure of discourse but not so marked as that of aphasic subjects. The main impairments of RHD patients' discourse can be observed at the level of text coherence. The both populations have also preserved cognitive representation concerned with script knowledge. Discourse processing at macrostructural level of discourse is affected in aphasics as well as in RHD patients. These results suggest that both hemispheres are necessary for normal discourse processes.

  11. Do environmental barriers affect the parent-reported quality of life of children and adolescents with cerebral palsy?

    PubMed

    Badia, Marta; Begoña Orgaz, M; Gómez-Vela, María; Verdugo, Miguel A; Ullán, Ana M; Longo, Egmar

    2016-01-01

    Physical, social, and attitudinal environment may affect the quality of life (QoL) of children and adolescents with cerebral palsy (CP). Participants in this study included parents of 206 children and adolescents with CP (55.8% males) aged 8-18 years (M=11.96, SD=3). Distribution according to the Gross Motor Function Classification System (GMFCS) was 24.3% level I, 18% level II, 18% level III, 12.6% level IV, and 27.2 level V. Environmental barriers were assessed with the Spanish version of the European Child Environment Questionnaire (ECEQ), and QoL was assessed with the KIDSCREEN parents' version. The results of the correlation analysis revealed that GMFCS level, IQ, and type of schooling are significantly correlated with QoL. Barriers were also associated with QoL. A series of hierarchical regression analyses indicated that, after controlling for the effect of child and parent's variables, barriers at home and at school significantly contribute to QoL. These findings underscore the importance of providing interventions to produce environmental changes that contribute to the improvement of QoL.

  12. Cerebral Paragonimiasis.

    PubMed

    Miyazaki, I

    1975-01-01

    The first case of cerebral paragonimiasis was reported by Otani in Japan in 1887. This was nine years after Kerbert's discovery of the fluke in the lungs of Bengal tigers and seven years after a human pulmonary infection by the fluke was demonstrated by Baelz and Manson. The first case was a 26-year-old man who had been suffering from cough and hemosputum for one year. The patient developed convulsive seizures with subsequent coma and died. The postmortem examination showed cystic lesions in the right frontal and occipital lobes. An adult fluke was found in the occipital lesion and another was seen in a gross specimen of normal brain tissue around the affected occipital lobe. Two years after Otani's discovery, at autopsy a 29-year-old man with a history of Jacksonian seizure was reported as having cerebral paragonimiasis. Some time later, however, it was confirmed that the case was actually cerebral schistosomiasis japonica. Subsequently, cases of cerebral paragonimiasis were reported. However, the majority of these cases were not confirmed histologically. It was pointed out that some of these early cases were probably not Paragonimus infection. After World War II, reviews as well as case reports were published. Recently, investigations have been reported from Korea, with a clinicla study on 62 cases of cerebral paragonimiasis seen at the Neurology Department of the National Medical Center, Seoul, between 1958 and 1964. In 1971 Higashi described a statistical study on 105 cases of cerebral paragonimiasis that had been treated surgically in Japan.

  13. The calculating hemispheres: studies of a split-brain patient.

    PubMed

    Funnell, Margaret G; Colvin, Mary K; Gazzaniga, Michael S

    2007-06-11

    The purpose of the study was to investigate simple calculation in the two cerebral hemispheres of a split-brain patient. In a series of four experiments, the left hemisphere was superior to the right in simple calculation, confirming the previously reported left hemisphere specialization for calculation. In two different recognition paradigms, right hemisphere performance was at chance for all arithmetic operations, with the exception of subtraction in a two-alternative forced choice paradigm (performance was at chance when the lure differed from the correct answer by a magnitude of 1 but above chance when the magnitude difference was 4). In a recall paradigm, the right hemisphere performed above chance for both addition and subtraction, but performed at chance levels for multiplication and division. The error patterns in that experiment suggested that for subtraction and addition, the right hemisphere does have some capacity for approximating the solution even when it is unable to generate the exact solution. Furthermore, right hemisphere accuracy in addition and subtraction was higher for problems with small operands than with large operands. An additional experiment assessed approximate and exact addition in the two hemispheres for problems with small and large operands. The left hemisphere was equally accurate in both tasks but the right hemisphere was more accurate in approximate addition than in exact addition. In exact addition, right hemisphere accuracy was higher for problems with small operands than large, but the opposite pattern was found for approximate addition.

  14. Transcranial Doppler Sonography Reveals Reductions in Hemispheric Asymmetry in Healthy Older Adults during Vigilance

    PubMed Central

    Harwood, Amanda E.; Greenwood, Pamela M.; Shaw, Tyler H.

    2017-01-01

    Given that older adults are remaining longer in the workforce, their ability to perform demanding cognitive tasks such as vigilance assignments needs to be thoroughly examined, especially since many vigilance assignments affect public safety (e.g., aviation, medicine and long distance driving). Previous research exploring the relation between aging and vigilance is conflicted, with some studies finding decreased vigilance performance in older adults but others finding no effect of age. We sought a better understanding of effects of age on vigilance by assessing neurophysiological change over the course of a vigil in young (aged 18–24) and healthy older (aged 66–77) adults. To measure temporal changes in cerebral blood flow, participants underwent functional transcranial doppler (fTCD) recording during a 1 h vigilance task. Based on research showing a compensatory effect of increased left hemisphere activation during vigilance in young adults and the “hemispheric asymmetry reduction in older adults” (HAROLD) model, we predicted that during vigilance our older adults would show greater left hemisphere activation but perform at a similar level compared to young adults. While cerebral blood flow velocity (CBFV) declined over time in both groups, only young adults showed the typical right-lateralized CBFV pattern. Older adults showed greater left hemisphere activation consistent with the HAROLD model. However, the increased left hemisphere activation did not appear to be compensatory as the older adults performed at a significantly lower level compared to young adults over the vigil. Findings are discussed in terms of the HAROLD model of healthy aging and the resource theory of vigilance. PMID:28228722

  15. Speech disorders in right-hemisphere stroke.

    PubMed

    Dyukova, G M; Glozman, Z M; Titova, E Y; Kriushev, E S; Gamaleya, A A

    2010-07-01

    Clinical practice shows that right-hemisphere cerebral strokes are often accompanied by one speech disorder or another. The aim of the present work was to analyze published data addressing speech disorders in right-sided strokes. Questions of the lateralization of speech functions are discussed, with particular reference to the role of the right hemisphere in speech activity and the structure of speech pathology in right-hemisphere foci. Clinical variants of speech disorders, such as aphasia, dysprosody, dysarthria, mutism, and stutter are discussed in detail. Types of speech disorders are also discussed, along with the possible mechanisms of their formation depending on the locations of lesions in the axis of the brain (cortex, subcortical structures, stem, cerebellum) and focus size.

  16. Is Remodelling of Corticospinal Tract Terminations Originating in the Intact Hemisphere Associated with Recovery following Transient Ischaemic Stroke in the Rat?

    PubMed Central

    Mitchell, Emma J.; Dewar, Deborah; Maxwell, David J

    2016-01-01

    Following large strokes that encompass the cerebral cortex, it has been suggested that the corticospinal tract originating from the non-ischaemic hemisphere reorganises its pattern of terminal arborisation within the spinal cord to compensate for loss of function. However many strokes in humans predominantly affect subcortical structures with minimal involvement of the cerebral cortex. The aim of the present study was to determine whether remodelling of corticospinal terminals arising from the non-ischaemic hemisphere was associated with spontaneous recovery in rats with subcortical infarcts. Rats were subjected to transient middle cerebral artery occlusion or sham surgery and 28 days later, when animals exhibited functional recovery, cholera toxin b subunit was injected into the contralesional, intact forelimb motor cortex in order to anterogradely label terminals within cervical spinal cord segments. Infarcts were limited to subcortical structures and resulted in partial loss of corticospinal tract axons from the ischaemic hemisphere. Quantitative analysis revealed there was no significant difference in the numbers of terminals on the contralesional side of the spinal grey matter between ischaemic and sham rats. The results indicate that significant remodelling of the corticospinal tract from the non-ischaemic hemisphere is not associated with functional recovery in animals with subcortical infarcts. PMID:27014870

  17. The Cerebral Balance of Power: Confrontation or Cooperation?

    ERIC Educational Resources Information Center

    Sergent, Justine

    1982-01-01

    Two visual search experiments suggest that: cerebral lateralization of cognitive functions results from differences in sensorimotor resolution capacities of the hemispheres; both hemispheres can process verbal and visuospatial information analytically and holistically; and respective hemispheric competence is a function of the level of…

  18. Impairment Severity Selectively Affects the Control of Proximal and Distal Components of Reaching Movements in Children with Hemiplegic Cerebral Palsy

    ERIC Educational Resources Information Center

    Domellof, Erik; Rosblad, Birgit; Ronnqvist, Louise

    2009-01-01

    This study explored proximal-to-distal components during goal-directed reaching movements in children with mild or moderate hemiplegic cerebral palsy (HCP); [seven females, four males; mean age 8y 6mo; SD 27mo], compared with age-matched, typically developing children (seven females, five males; mean age 8y 3mo [SD 25mo]. Severity of HCP was…

  19. Identification and Functional Expression of a Glutamate- and Avermectin-Gated Chloride Channel from Caligus rogercresseyi, a Southern Hemisphere Sea Louse Affecting Farmed Fish

    PubMed Central

    Niemeyer, María Isabel; Marabolí, Vanessa; González-Nilo, F. Danilo; Teulon, Jacques; Sepúlveda, Francisco V.; Cid, L. Pablo

    2014-01-01

    Parasitic sea lice represent a major sanitary threat to marine salmonid aquaculture, an industry accounting for 7% of world fish production. Caligus rogercresseyi is the principal sea louse species infesting farmed salmon and trout in the southern hemisphere. Most effective control of Caligus has been obtained with macrocyclic lactones (MLs) ivermectin and emamectin. These drugs target glutamate-gated chloride channels (GluCl) and act as irreversible non-competitive agonists causing neuronal inhibition, paralysis and death of the parasite. Here we report the cloning of a full-length CrGluClα receptor from Caligus rogercresseyi. Expression in Xenopus oocytes and electrophysiological assays show that CrGluClα is activated by glutamate and mediates chloride currents blocked by the ligand-gated anion channel inhibitor picrotoxin. Both ivermectin and emamectin activate CrGluClα in the absence of glutamate. The effects are irreversible and occur with an EC50 value of around 200 nM, being cooperative (nH = 2) for ivermectin but not for emamectin. Using the three-dimensional structure of a GluClα from Caenorabditis elegans, the only available for any eukaryotic ligand-gated anion channel, we have constructed a homology model for CrGluClα. Docking and molecular dynamics calculations reveal the way in which ivermectin and emamectin interact with CrGluClα. Both drugs intercalate between transmembrane domains M1 and M3 of neighbouring subunits of a pentameric structure. The structure displays three H-bonds involved in this interaction, but despite similarity in structure only of two these are conserved from the C. elegans crystal binding site. Our data strongly suggest that CrGluClα is an important target for avermectins used in the treatment of sea louse infestation in farmed salmonids and open the way for ascertaining a possible mechanism of increasing resistance to MLs in aquaculture industry. Molecular modeling could help in the design of new, more efficient

  20. Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans.

    PubMed

    Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G; Kalsi, Kameljit K; Secher, Niels H; González-Alonso, José

    2014-07-15

    Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle cerebral artery velocity (MCA Vmean), arterial-venous differences and blood temperature in 10 trained males during incremental cycling to exhaustion in the heat (35°C) in control, dehydrated and rehydrated states. Dehydration reduced body mass (75.8 ± 3 vs. 78.2 ± 3 kg), increased internal temperature (38.3 ± 0.1 vs. 36.8 ± 0.1°C), impaired exercise capacity (269 ± 11 vs. 336 ± 14 W), and lowered ICA and MCA Vmean by 12-23% without compromising CCA blood flow. During euhydrated incremental exercise on a separate day, however, exercise capacity and ICA, MCA Vmean and CCA dynamics were preserved. The fast decline in cerebral perfusion with dehydration was accompanied by increased O2 extraction (P < 0.05), resulting in a maintained cerebral metabolic rate for oxygen (CMRO2). In all conditions, reductions in ICA and MCA Vmean were associated with declining cerebral vascular conductance, increasing jugular venous noradrenaline, and falling arterial carbon dioxide tension (P aCO 2) (R(2) ≥ 0.41, P ≤ 0.01) whereas CCA flow and conductance were related to elevated blood temperature. In conclusion, dehydration accelerated the decline in CBF by decreasing P aCO 2 and enhancing vasoconstrictor activity. However, the circulatory strain on the human brain during maximal exercise does not compromise CMRO2 because of compensatory increases in O2 extraction.

  1. Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans

    PubMed Central

    Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G; Kalsi, Kameljit K; Secher, Niels H; González-Alonso, José

    2014-01-01

    Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle cerebral artery velocity (MCA Vmean), arterial–venous differences and blood temperature in 10 trained males during incremental cycling to exhaustion in the heat (35°C) in control, dehydrated and rehydrated states. Dehydration reduced body mass (75.8 ± 3 vs. 78.2 ± 3 kg), increased internal temperature (38.3 ± 0.1 vs. 36.8 ± 0.1°C), impaired exercise capacity (269 ± 11 vs. 336 ± 14 W), and lowered ICA and MCA Vmean by 12–23% without compromising CCA blood flow. During euhydrated incremental exercise on a separate day, however, exercise capacity and ICA, MCA Vmean and CCA dynamics were preserved. The fast decline in cerebral perfusion with dehydration was accompanied by increased O2 extraction (P < 0.05), resulting in a maintained cerebral metabolic rate for oxygen (CMRO2). In all conditions, reductions in ICA and MCA Vmean were associated with declining cerebral vascular conductance, increasing jugular venous noradrenaline, and falling arterial carbon dioxide tension () (R2 ≥ 0.41, P ≤ 0.01) whereas CCA flow and conductance were related to elevated blood temperature. In conclusion, dehydration accelerated the decline in CBF by decreasing and enhancing vasoconstrictor activity. However, the circulatory strain on the human brain during maximal exercise does not compromise CMRO2 because of compensatory increases in O2 extraction. PMID:24835170

  2. Individual Differences in Hemispheric Specialization

    DTIC Science & Technology

    1987-11-01

    Aphasia affecting the cerebral nemisphere on the same side as the preferred hand has also long been understood. Individual variation in degree...no LVF superiority for recognising dot patterns (Harcum and Dyer, 1962) and no differences between sides to a unilateral auditory stimulus...equal frequency after either left or right sides lesions, sinistrals with only dextral relatives tended to develop aphasia after only left sided

  3. Hemisphere Asymmetry of Response to Pharmacologic Treatment in an Alzheimer’s Disease Mouse Model

    PubMed Central

    Manousopoulou, Antigoni; Saito, Satoshi; Yamamoto, Yumi; Al-Daghri, Nasser M.; Ihara, Masafumi; Carare, Roxana O.; Garbis, Spiros D.

    2016-01-01

    The aim of this study was to examine hemisphere asymmetry of response to pharmacologic treatment in an Alzheimer’s disease mouse model using cilostazol as a chemical stimulus. Eight-month-old mice were assigned to vehicle or cilostazol treatment for three months and hemispheres were analyzed using quantitative proteomics. Bioinformatics interpretation showed that following treatment, aggregation of blood platelets significantly decreased in the right hemisphere whereas neurodegeneration significantly decreased and synaptic transmission increased in the left hemisphere only. Our study provides novel evidence on cerebral laterality of pharmacologic activity, with important implications in deciphering regional pharmacodynamic effects of existing drugs thus uncovering novel hemisphere-specific therapeutic targets. PMID:26836196

  4. Southern hemisphere observations

    NASA Astrophysics Data System (ADS)

    Orchiston, Wayne

    Because of insurmountable problems associated with absolute dating, the non-literate cultures of the Southern Hemisphere can contribute little to Applied Historical Astronomy, although Maori traditions document a possible supernova dating to the period 1000-1770 AD. In contrast, the abundant nineteenth century solar, planetary, cometary and stellar observational data provided by Southern Hemisphere professional and amateur observatories can serve as an invaluable mine of information for present-day astronomers seeking to incorporate historical data in their investigations.

  5. Gender Differences in Empathy: The Role of the Right Hemisphere

    ERIC Educational Resources Information Center

    Rueckert, Linda; Naybar, Nicolette

    2008-01-01

    The relationship between activation of the right cerebral hemisphere (RH) and empathy was investigated. Twenty-two men and 73 women participated by completing a chimeric face task and empathy questionnaire. For the face task, participants were asked to pick which of the two chimeric faces looked happier. Both men and women were significantly more…

  6. Hemispheric Differences in the Recruitment of Semantic Processing Mechanisms

    ERIC Educational Resources Information Center

    Kandhadai, Padmapriya; Federmeier, Kara D.

    2010-01-01

    This study examined how the two cerebral hemispheres recruit semantic processing mechanisms by combining event-related potential measures and visual half-field methods in a word priming paradigm in which semantic strength and predictability were manipulated using lexically associated word pairs. Activation patterns on the late positive complex…

  7. Hemispheric Differences in Indexical Specificity Effects in Spoken Word Recognition

    ERIC Educational Resources Information Center

    Gonzalez, Julio; McLennan, Conor T.

    2007-01-01

    Variability in talker identity, one type of indexical variation, has demonstrable effects on the speed and accuracy of spoken word recognition. Furthermore, neuropsychological evidence suggests that indexical and linguistic information may be represented and processed differently in the 2 cerebral hemispheres, and is consistent with findings from…

  8. About Hemispheric Differences in the Processing of Temporal Intervals

    ERIC Educational Resources Information Center

    Grondin, S.; Girard, C.

    2005-01-01

    The purpose of the present study was to identify differences between cerebral hemispheres for processing temporal intervals ranging from .9 to 1.4s. The intervals to be judged were marked by series of brief visual signals located in the left or the right visual field. Series of three (two standards and one comparison) or five intervals (four…

  9. Hemispherical Laue camera

    DOEpatents

    Li, James C. M.; Chu, Sungnee G.

    1980-01-01

    A hemispherical Laue camera comprises a crystal sample mount for positioning a sample to be analyzed at the center of sphere of a hemispherical, X-radiation sensitive film cassette, a collimator, a stationary or rotating sample mount and a set of standard spherical projection spheres. X-radiation generated from an external source is directed through the collimator to impinge onto the single crystal sample on the stationary mount. The diffracted beam is recorded on the hemispherical X-radiation sensitive film mounted inside the hemispherical film cassette in either transmission or back-reflection geometry. The distances travelled by X-radiation diffracted from the crystal to the hemispherical film are the same for all crystal planes which satisfy Bragg's Law. The recorded diffraction spots or Laue spots on the film thereby preserve both the symmetry information of the crystal structure and the relative intensities which are directly related to the relative structure factors of the crystal orientations. The diffraction pattern on the exposed film is compared with the known diffraction pattern on one of the standard spherical projection spheres for a specific crystal structure to determine the orientation of the crystal sample. By replacing the stationary sample support with a rotating sample mount, the hemispherical Laue camera can be used for crystal structure determination in a manner previously provided in conventional Debye-Scherrer cameras.

  10. Hemispheric contributions to pragmatics.

    PubMed

    Zaidel, E; Kasher, A; Soroker, N; Batori, G; Giora, R; Graves, D

    2000-01-01

    Twenty-seven patients with right-hemisphere damage (RBD) and thirty-one patients with left-hemisphere damage (LBD) received a new pragmatics battery in Hebrew consisting of two parts: (1) comprehension and production of basic speech acts (BSAs), including tests of assertions, questions, requests, and commands, and (2) comprehension of implicatures, including implicatures of quantity, quality, relevance, and manner. Each test had a verbal and a nonverbal version. Patients also received Hebrew versions of the Western Aphasia Battery and of the Right Hemisphere Communication Battery. Both LBD and RBD patients were impaired relative to controls but did not differ from each other in their overall scores on BSAs and on Implicatures when scores were corrected by aphasia and neglect indices. There was a systematic localization of BSAs in the left hemisphere (LH) but not in the right hemisphere (RH). There was poor localization of Implicatures in either hemisphere. In LBD patients, BSAs were associated with language functions measured with the WAB, suggesting the radical possibility that the classic localization of language functions in aphasia is influenced by the localization of the BSAs required by aphasia language tests. Both BSAs and implicatures show greater functional independence from other pragmatic, language and cognitive functions in the RBD than in the LBD patients. Thus, the LH is more likely to contain an unmodular domain-nonspecific set of central cognitive mechanisms for applying means-ends rationality principles to intentional activity.

  11. Individual differences in relative hemispheric alpha abundance and cognitive responses to persuasive communications.

    PubMed

    Cacioppo, J T; Petty, R E; Quintanar, L R

    1982-09-01

    Three experiments are reported investigating individual differences in interhemispheric electroencephalogram (EEG) activity and cognitive responses to persuasion. Experiment 1 indicated that subjects who were characterized by relative left hemispheric EEG activity over the parietal areas also produced a less affectively polarized profile of thought listings about the persuasive communication. Moreover, this individual difference emerged only when subjects were confronted by the forewarning and message; the basal patterns of interhemispheric EEG activity, which were obtained prior to the announcement of the attitudinal recommendation, did not portend distinguishable profiles of cognitive responding. Experiment 2 replicated the major findings of Experiment 1 using different topics and a within-subjects rather than a between-subjects design. Further analyses suggested that thinking about an attitude issue rather than responding to a persuasive communication was sufficient to obtain the above relationship between interhemispheric EEG alpha abundance and cognitive response. Experiment 3 used Tesser's time-to-think procedure to assess interhemispheric EEG patterning as a function of the affective polarization of topic-relevant thinking. The results supported the expectation that as subjects thought longer about attitude issues they exhibited a shifting of relative hemispheric EEG activity from the left toward the right parietal areas of the cerebral hemispheres. The significance and limitations of these findings for research on attitude change and the utility of including psychophysiological approaches to elusive research problems in personality and social psychology are discussed.

  12. Finding the Right Word: Hemispheric Asymmetries in the Use of Sentence Context Information

    ERIC Educational Resources Information Center

    Wlotko, Edward W.; Federmeier, Kara D.

    2007-01-01

    The cerebral hemispheres have been shown to be differentially sensitive to sentence-level information; in particular, it has been suggested that only the left hemisphere (LH) makes predictions about upcoming items, whereas the right (RH) processes words in a more integrative fashion. The current study used event-related potentials to jointly…

  13. Hemispheric Differences in Strong versus Weak Semantic Priming: Evidence from Event-Related Brain Potentials

    ERIC Educational Resources Information Center

    Frishkoff, Gwen A.

    2007-01-01

    Goals: Research with lateralized word presentation has suggested that strong ("close") and weak ("remote") semantic associates are processed differently in the left and right cerebral hemispheres [e.g., Beeman, M. j., & Chiarello, C. (1998). Complementary right- and left-hemisphere language comprehension. "Current Directions in Psychological…

  14. Priming vs. Rhyming: Orthographic and Phonological Representations in the Left and Right Hemispheres

    ERIC Educational Resources Information Center

    Lindell, Annukka K.; Lum, Jarrad A. G.

    2008-01-01

    The right cerebral hemisphere has long been argued to lack phonological processing capacity. Recently, however, a sex difference in the cortical representation of phonology has been proposed, suggesting discrete left hemisphere lateralization in males and more distributed, bilateral representation of function in females. To evaluate this…

  15. Millennial δ18O oscillations from a replicated Holocene speleothem record from Iberian Peninsula and hemispherical teleconecctions affecting the water cycle

    NASA Astrophysics Data System (ADS)

    Domínguez-Villar, David; Wang, Xianfeng; Krklec, Kristina; Cheng, Hai; Edwards, R. Lawrence

    2016-04-01

    We present a speleothem δ18O record from Kaite Cave in northern Iberian Peninsula covering the last 9.7 ka BP. The record is constructed from four different stalagmites that replicate each other. The age model is based on 63 U-Th dates and over 4500 laminae providing a robust time frame for the record. The δ18O record has characteristic millennial oscillations through the Holocene with periodicity around 2 ka during the Late Holocene and around 1 ka during the Early Holocene. Causes of the millennial δ18O variability are not dominated by the amount of rainfall or atmospheric temperature and other controls of the water cycle are more relevant. The aquifer at this site filters any seasonal bias and speleothems records the inter-annual δ18O variability in precipitation. On the other hand, moisture source analysis at this site shows that significant amount of precipitation is from recycled moisture (continental origin). A variable proportion of this parameter is capable to impact significantly past values of δ18O in precipitation. Thus, we interpret the millennial oscillations of the δ18O record as changes in the hydrological cycle resulting from variable percentages of the recycled precipitation over the Iberian Peninsula. We found that variable amount of recycled precipitation in Iberian Peninsula is related to the location of the Iceland Low pressure cell, although does not correlate with NAO index. Correlation of Kaite δ18O record during the Holocene with other representative records suggests that millennial oscillations are caused by variability of the Gulf Stream/North Atlantic Current that affects atmospheric pressure fields in the North Atlantic. Further correlation of Kaite δ18O record along the world supports that the recorded millennial oscillations of the water cycle are related to persistent variability on the tropical North Atlantic. Only during periods of major sea-ice variability in high-latitudes of the North Atlantic, the later region replaces

  16. Spatial disorientation in right-hemisphere infarction.

    PubMed Central

    Meerwaldt, J D; van Harskamp, F

    1982-01-01

    Spatial orientation was tested with the rod orientation test. The subjects were 40 normal controls and 68 brain-damaged patients with cerebral infarcts. Patients in whom the lesion included the post-rolandic region of the right hemisphere performed worse than controls or patients with lesions at other sites. Patients with an exclusively postrolandic (usually occipital) lesion showed higher error rates than patients with a combined prerolandic and postrolandic lesion, but only for the visual part of the test. These patients were re-examined one year after the stroke. Most of them showed an incomplete recovery of spatial function. PMID:7119828

  17. Anxiety and Lateral Cerebral Function

    ERIC Educational Resources Information Center

    Tucker, Don M.; And Others

    1978-01-01

    Examines the effect of stressful and nonstressful experimental situations upon the processing capacity of each cerebral hemisphere, through observing the differential performance tasks presented to right and left visual half-fields (VHFs). Also examines attentional bias and lateral eye movements. (Author/RK)

  18. Cerebral malaria

    PubMed Central

    Newton, C.; Hien, T. T.; White, N.

    2000-01-01

    Cerebral malaria may be the most common non-traumatic encephalopathy in the world. The pathogenesis is heterogenous and the neurological complications are often part of a multisystem dysfunction. The clinical presentation and pathophysiology differs between adults and children. Recent studies have elucidated the molecular mechanisms of pathogenesis and raised possible interventions. Antimalarial drugs, however, remain the only intervention that unequivocally affects outcome, although increasing resistance to the established antimalarial drugs is of grave concern. Artemisinin derivatives have made an impact on treatment, but other drugs may be required. With appropriate antimalarial drugs, the prognosis of cerebral malaria often depends on the management of other complications—for example, renal failure and acidosis. Neurological sequelae are increasingly recognised, but further research on the pathogenesis of coma and neurological damage is required to develop other ancillary treatments.

 PMID:10990500

  19. Familial Congenital Unilateral Cerebral Ventriculomegaly: Delineation of a Distinct Genetic Disorder

    PubMed Central

    Zaki, Maha S.; Afifi, Hanan H.; Barkovich, AJ.; Gleeson, Joseph G.

    2016-01-01

    We identified two female siblings, derived from healthy first cousin parents, with congenital unilateral cerebral ventriculomegaly detected prenatally. Patient 1 underwent ventriculoperitoneal shunt operation at 1 week old, while Patient 2 was followed without surgical intervention. Both patients presented with mild developmental delay and hemiparesis contralateral to the involved hemisphere. Focal seizures were observed in Patient 1, whose neuroimaging revealed posterior insular polymicrogyria in the normal sized ventricle hemisphere and retrocerebellar cyst. Both siblings displayed near absence of white matter with marked thinning of the overlying cortex in the affected hemisphere and very thin corpus callosum. Investigations revealed no other system involvement and karyotyping was normal. Normal TORCH screening in subsequent pregnancies, normal parental coagulation profile and undetectable maternal autoantibodies suggested against the possible role of extrinsic factors as an etiological factor for unilateral ventriculomegaly. Parents had normal brain imaging findings. We suggest delineation of a distinct developmental brain defect, most likely of autosomal recessive inheritance. PMID:19610102

  20. Hemispheric differences in solar wind - magnetosphere interactions

    NASA Astrophysics Data System (ADS)

    Reistad, J. P.; Ostgaard, N.; Laundal, K.; Snekvik, K.; Tenfjord, P.; Oksavik, K.

    2014-12-01

    Although the aurora to a large degree behave similar in the two hemispheres, recent simultaneous observations of the global aurora from space have revealed that sometimes rather large intensity and location asymmetries are present in the global aurora. From event studies using e.g. conjugate imaging, multiple mechanisms have been proposed to be responsible for the asymmetric aurora. However, we know very little about their general importance. We have investigated the general importance of an asymmetric solar wind dynamo. It has been suggested that the radial component of the IMF can modify the energy conversion between the solar wind and magnetosphere differently in the two hemispheres in a general sense. By looking at the global aurora using IMAGE WIC during carefully selected events minimally contaminated by other mechanisms affecting the two hemispheres differently, we find that the dusk side aurora depend oppositely on the radial IMF direction in the two hemispheres. These results are consistent with an asymmetric solar wind dynamo where the hemispheric preference is controlled by the radial IMF. This is the first study indicating the importance of the asymmetric solar wind dynamo in a general sense. A different mechanism, the asymmetric loading of magnetic flux during IMF By conditions is also expected to account for North-South asymmetries in the nightside global aurora. This will be investigated using a similar approach to establish the general importance of of this IMF By mechanism on the global aurora in the two hemispheres.

  1. Hemispheric differences of motor execution: a near-infrared spectroscopy study.

    PubMed

    Helmich, Ingo; Rein, Robert; Niermann, Nico; Lausberg, Hedda

    2013-01-01

    Distal movements of the limbs are predominantly controlled by the contralateral hemisphere. However, functional neuroimaging studies do not unequivocally demonstrate a lateralization of the cerebral activation during hand movements. While some studies show a predominant activation of the contralateral hemisphere, other studies provide evidence for a symmetrically distributed bihemispheric activation. However, the divergent results may also be due to methodological shortcomings. Therefore, the present study using functional near-infrared spectroscopy examines cerebral activation in both hemispheres during motor actions of the right and left hands. Twenty participants performed a flexion/extension task with the right- or left-hand thumb. Cerebral oxygenation changes were recorded from 48 channels over the primary motor, pre-motor, supplementary motor, primary somatosensory cortex, subcentral area, and the supramarginal gyrus of each hemisphere. A consistent increase of cerebral oxygenation was found for oxygenated and for total hemoglobin in the hemisphere contralateral to the moving hand, regardless of the laterality. These findings are in line with previous data from localization [1-3] and brain imaging studies [4-6]. The present data support the proposition that there is no hemispheric specialization for simple distal motor tasks. Both hemispheres are equally activated during movement of the contralateral upper limb.

  2. Hemispheric Asymmetries in Children.

    ERIC Educational Resources Information Center

    Lewandowski, Lawrence

    1982-01-01

    Hemispheric specialization tasks were given to different-aged boys. Asymmetries were demonstrated on manual, visual, and auditory tasks; however, the degree of asymmetries did not change across age groups. There appears to be a dissociation between visual and auditory perceptual asymmetries. (Author/RD)

  3. Hemispheric lateralization in reasoning.

    PubMed

    Turner, Benjamin O; Marinsek, Nicole; Ryhal, Emily; Miller, Michael B

    2015-11-01

    A growing body of evidence suggests that reasoning in humans relies on a number of related processes whose neural loci are largely lateralized to one hemisphere or the other. A recent review of this evidence concluded that the patterns of lateralization observed are organized according to two complementary tendencies. The left hemisphere attempts to reduce uncertainty by drawing inferences or creating explanations, even at the cost of ignoring conflicting evidence or generating implausible explanations. Conversely, the right hemisphere aims to reduce conflict by rejecting or refining explanations that are no longer tenable in the face of new evidence. In healthy adults, the hemispheres work together to achieve a balance between certainty and consistency, and a wealth of neuropsychological research supports the notion that upsetting this balance results in various failures in reasoning, including delusions. However, support for this model from the neuroimaging literature is mixed. Here, we examine the evidence for this framework from multiple research domains, including an activation likelihood estimation analysis of functional magnetic resonance imaging studies of reasoning. Our results suggest a need to either revise this model as it applies to healthy adults or to develop better tools for assessing lateralization in these individuals.

  4. Cerebral Palsy (For Parents)

    MedlinePlus

    ... palsy — causes a problem with balance and depth perception Since cerebral palsy affects muscle control and coordination, ... fluid into the lungs) gastroesophageal reflux (spitting up) speech problems drooling tooth decay sleep disorders osteoporosis (weak, ...

  5. Hemispheric modulations of the attentional networks.

    PubMed

    Spagna, Alfredo; Martella, Diana; Fuentes, Luis J; Marotta, Andrea; Casagrande, Maria

    2016-10-01

    Although several recent studies investigated the hemispheric contributions to the attentional networks using the Attention Network Test (ANT), the role of the cerebral hemispheres in modulating the interaction among them remains unclear. In this study, two lateralized versions of this test (LANT) were used to investigate theal effects on the attentional networks under different conflict conditions. One version, the LANTI-A, presented arrows as target and flankers, while the other version, the LANTI-F, had fruits as target and flankers. Data collected from forty-seven participants confirmed well-known results on the efficiency and interactions among the attentional networks. Further, a left visual field advantage was found when a target occurred in an unattended location (e.g. invalid trials), only with the LANTI-F, but not with LANTI-A. The present study adds more evidence to the hemispheric asymmetry of the orienting of attention, and further reveals patterns of interactions between the attentional networks and the visual fields across different conflicting conditions, underlying the dynamic control of attention in complex environments.

  6. Cerebral Asymmetry and the Development of Infantile Autism. Report No. 64.

    ERIC Educational Resources Information Center

    Blackstock, Edward G.

    The notion that autistic children process information predominantly by strategies of the right cerebral hemisphere from birth, and unless unusual events occur, continue to be right hemisphere processors throughout their life, is examined. Evidence that suggests that cerebral dominance may be present at birth in normal humans, and that for normal…

  7. Hemispherical spondylosclerosis - a polyetiologic syndrome

    SciTech Connect

    Dihlmann, W.

    1981-11-01

    Radiologic examination of 43 patients revealed 47 lesions of a type which we have termed hemispherical spondylosclerosis (HSS). This term describes and includes the following essential and possible radiologic findings of the disease: 1) Hemispherical (or dome - or helmet-shaped ) sclerosis of the vertebra above the intervertebral disk. Thus it is a supradiscal HSS. 2) One or more small erosions of the inferior end plate of the vertebra involved. 3) Periosteal apposition on the anterior border of the vertebra along the length of the sclerosis. 4) New bone formation on the inferior end plate. 5) Anterior vertebral osteophytes. 6) Narrowing of the disk space below the affected vertebra. HSS occurs not only as a sequel of degenerative disk disease, but also in bacterial (tuberculous and non-tuberculous) spondylitis, ankylosing spondylitis, osteoid osteoma, and metastases of neoplasms. The differential diagnosis between inflammatory and non-inflammatory pathogenesis and etiology of HSS is described. The characteristic shape of HSS, its sites of predilection (L4 >> L5 > L3), and the preponderance of female sufferers from this painful condition are due to factors which, as yet, remain unknown.

  8. Brain Hemisphericity and Developmental Dyslexia

    ERIC Educational Resources Information Center

    Vlachos, Filippos; Andreou, Eleni; Delliou, Afroditi

    2013-01-01

    The present study examined the link between brain hemisphericity and dyslexia in secondary school students, using the Preference Test (PT), a widely used self-report index of preferred hemisphere thinking styles. The hypothesis was that differences would be revealed between the dyslexic group and their peers in hemispheric preference. A total of…

  9. Humeral external rotation handling by using the Bobath concept approach affects trunk extensor muscles electromyography in children with cerebral palsy.

    PubMed

    Grazziotin Dos Santos, C; Pagnussat, Aline S; Simon, A S; Py, Rodrigo; Pinho, Alexandre Severo do; Wagner, Mário B

    2014-10-20

    This study aimed to investigate the electromyographic activity of cervical and trunk extensors muscles in children with cerebral palsy during two handlings according to the Bobath concept. A crossover trial involving 40 spastic diplegic children was conducted. Electromyography (EMG) was used to measure muscular activity at sitting position (SP), during shoulder internal rotation (IR) and shoulder external rotation (ER) handlings, which were performed using the elbow joint as key point of control. Muscle recordings were performed at the fourth cervical (C4) and at the tenth thoracic (T10) vertebral levels. The Gross Motor Function Classification System (GMFCS) was used to assess whether muscle activity would vary according to different levels of severity. Humeral ER handling induced an increase on EMG signal of trunk extensor muscles at the C4 (P=0.007) and T10 (P<0.001) vertebral levels. No significant effects were observed between SP and humeral IR handling at C4 level; However at T10 region, humeral IR handling induced an increase of EMG signal (P=0.019). Humeral ER resulted in an increase of EMG signal at both levels, suggesting increase of extensor muscle activation. Furthermore, the humeral ER handling caused different responses on EMG signal at T10 vertebra level, according to the GMFCS classification (P=0.017). In summary, an increase of EMG signal was observed during ER handling in both evaluated levels, suggesting an increase of muscle activation. These results indicate that humeral ER handling can be used for diplegic CP children rehabilitation to facilitate cervical and trunk extensor muscles activity in a GMFCS level-dependent manner.

  10. Cerebral Correlates of Amygdala Responses During Non-Conscious Perception of Facial Affect in Adolescent and Pre-Adolescent Children

    PubMed Central

    Killgore, William D. S.; Yurgelun-Todd, Deborah A.

    2009-01-01

    During nonconscious perception of facial affect, healthy adults commonly activate a right-lateralized pathway comprising the superior colliculus, pulvinar, and amygdala. Whether this system is fully developed prior to adulthood is unknown. Twenty-three healthy adolescents underwent functional magnetic resonance imaging (fMRI) while viewing fearful, angry, and happy faces, backward masked by neutral faces. Left amygdala activation differed among the three affects, showing reductions to masked anger and increases to masked fear and happy faces. During masked fear, left amygdala activation correlated positively with extrastriate cortex and temporal poles and negatively with precuneus and middle cingulate gyrus. Responses of the left amygdala to masked anger correlated positively with right parahippocampal gyrus and negatively with dorsal anterior cingulate. Amygdala responses to masked happy faces were uncorrelated with other brain regions. Contrary to the right-lateralized pathway seen in adults, adolescents show evidence of a predominantly left-lateralized extrastriate pathway during masked presentations of facial affect. PMID:20200600

  11. Reorganization of the cerebro-cerebellar network of language production in patients with congenital left-hemispheric brain lesions.

    PubMed

    Lidzba, K; Wilke, M; Staudt, M; Krägeloh-Mann, I; Grodd, W

    2008-09-01

    Patients with congenital lesions of the left cerebral hemisphere may reorganize language functions into the right hemisphere. In these patients, language production is represented homotopically to the left-hemispheric language areas. We studied cerebellar activation in five patients with congenital lesions of the left cerebral hemisphere to assess if the language network is reorganized completely in these patients, i.e. including also cerebellar language functions. As compared to a group of controls matched for age, sex, and verbal IQ, the patients recruited an area not in the right but in the left cerebellar hemisphere. The extent of laterality of the cerebellar activation correlated significantly with the laterality of the frontal activation. We suggest that the developing brain reacts to early focal lesions in the left hemisphere with a mirror-image organization of the entire cerebro-cerebellar network engaged in speech production.

  12. Epilepsy, cerebral blood flow, and cerebral metabolic rate.

    PubMed

    Duncan, R

    1992-01-01

    Penfield's observations in the 1930s provided the first systematic evidence of changes in regional cerebral blood flow (rCBF) associated with focal seizures. Further studies in humans and animals confirmed increases in cerebral blood flow and metabolism during generalised seizures, but the interictal, ictal, and postictal changes in focal epilepsy have begun to be elucidated in the last decade with the advent of in vivo imaging techniques such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) and, in the case of animal studies, of autoradiography. Most studies have been of temporal lobe epilepsy. Interictally, the characteristic finding has been reduced blood flow and/or metabolism in the affected temporal lobe, or more extensively in the ipsilateral hemisphere. The few studies to date of ictal or postictal changes have been of rCBF using SPECT. They show hyperperfusion of the whole temporal lobe ictally, hyperperfusion of the hippocampus, combined with hypoperfusion of lateral structures in the immediate postictal period. Later in the postictal period, hypoperfusion alone is seen. Studies of focal seizures in animals have shown hyperperfusion and hypermetabolism at the site of the focus often with widespread depression of both parameters in the ipsilateral neocortex. Limited studies of coupling between blood flow and metabolism in humans have suggested that flow during seizures is adequate for metabolic demand, although some animal studies have suggested localised areas of uncoupling. The results of modern in vivo imaging of ictal and postictal changes in blood flow and metabolism have correlated well with Penfield's observations, and these changes are now being used to help localise epileptic foci, allowing wider use of the surgical treatment he pioneered.

  13. Differential Impact of Posterior Lesions in the Left and Right Hemisphere on Visual Category Learning and Generalization to Contrast Reversal

    ERIC Educational Resources Information Center

    Langguth, Berthold; Juttner, Martin; Landis, Theodor; Regard, Marianne; Rentschler, Ingo

    2009-01-01

    Hemispheric differences in the learning and generalization of pattern categories were explored in two experiments involving sixteen patients with unilateral posterior, cerebral lesions in the left (LH) or right (RH) hemisphere. In each experiment participants were first trained to criterion in a supervised learning paradigm to categorize a set of…

  14. Hemispheric Differences in the Time-Course of Semantic Priming Processes: Evidence from Event-Related Potentials (ERPs)

    ERIC Educational Resources Information Center

    Bouaffre, Sarah; Faita-Ainseba, Frederique

    2007-01-01

    To investigate hemispheric differences in the timing of word priming, the modulation of event-related potentials by semantic word relationships was examined in each cerebral hemisphere. Primes and targets, either categorically (silk-wool) or associatively (needle-sewing) related, were presented to the left or right visual field in a go/no-go…

  15. Triton's Southern Hemisphere

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This polar projection of Triton's southern hemisphere provides a view of the southern polar cap and bright equatorial fringe. The margin of the cap is scalloped and ranges in latitude from +10 degrees to -30 degrees. The bright fringe is closely associated with the cap's margin; from it, diffuse bright rays extend north-northeast for hundreds of kilometers. The bright fringe probably consists of very fresh nitrogen frost or snow, and the rays consist of bright-fringe materials that were redistributed by north-moving Coriolis-deflected winds.

  16. Hemispherical latching apparatus

    NASA Technical Reports Server (NTRS)

    Clark, K. H. (Inventor)

    1985-01-01

    An apparatus for securing payloads in a space vehicle such as the space shuttle is described. The apparatus includes many latching assemblies carried by a platform on the vehicle and a like number of latching elements carried by the payload and adapted to mate with the latching assemblies. The novelty of the invention is believed to reside in the use of complementary hemispherical elements which automatically align and engage with one another. This enables a simple but effective mode of operation and avoids the need for hinged linkages and similar moving parts.

  17. Analysing coupling architecture in the cortical EEG of a patient with unilateral cerebral palsy

    NASA Astrophysics Data System (ADS)

    Kornilov, Maksim V.; Baas, C. Marjolein; van Rijn, Clementina M.; Sysoev, Ilya V.

    2016-04-01

    The detection of coupling presence and direction between cortical areas from the EEG is a popular approach in neuroscience. Granger causality method is promising for this task, since it allows to operate with short time series and to detect nonlinear coupling or coupling between nonlinear systems. In this study EEG multichannel data from adolescent children, suffering from unilateral cerebral palsy were investigated. Signals, obtained in rest and during motor activity of affected and less affected hand, were analysed. The changes in inter-hemispheric and intra-hemispheric interactions were studied over time with an interval of two months. The obtained results of coupling were tested for significance using surrogate times series. In the present proceeding paper we report the data of one patient. The modified nonlinear Granger causality is indeed able to reveal couplings within the human brain.

  18. Large subcortical hemispheric infarctions. Presentation and prognosis.

    PubMed

    Levine, R L; Lagreze, H L; Dobkin, J A; Turski, P A

    1988-10-01

    A specific form of large subcortical hemispheric infarction on computed tomography was identified in 24 of 2198 (1%) stroke registry patients. Combined with 13 cases from earlier literature reports, a characteristic neurologic picture developed. Severe face plus arm plus leg weakness at onset (76%), corticallike features of aphasia and/or contralateral neglect (68%), and premonitory transient ischemic attacks (24%) were frequent. Twenty-two patients (59%) had large vessel arterial occlusive disease. Eight patients (22%) had primary embolic occlusion in the middle cerebral artery territory. During an average follow-up of 16 months, five patients (14%) suffered recurrent stroke or death. The clinical presentation and prognostic features of this distinct stroke subtype are described.

  19. Volumetric assessment of cerebral asymmetries in dogs.

    PubMed

    Siniscalchi, Marcello; Franchini, Delia; Pepe, Anna M; Sasso, Raffaella; Dimatteo, Salvatore; Vallortigara, Giorgio; Quaranta, Angelo

    2011-09-01

    In the present study we quantified volumetric brain asymmetries from computed tomography (CT) scans in 12 healthy dogs, using a semi-automated technique for assessing in vivo structure asymmetry. Volumetric assessment of asymmetrical cerebral lateral ventricle (ALV) was also investigated. Our results showed that seven dogs exhibited a right hemisphere significantly greater than the left, two dogs had a left-greater-than-right hemisphere asymmetry, and finally two dogs displayed no significant brain volumetric asymmetry. This right-biased hemispheric asymmetry supports data reported previously using post-mortem morphological studies in both dogs and other mammalian species.

  20. A hemispherical dynamo on Mars?

    NASA Astrophysics Data System (ADS)

    Dietrich, Wieland; Wicht, Johannes; Hori, Kumiko

    2015-04-01

    Numerous threedimensional MHD models investigated the induction of planetary magnetic fields under the influence of a laterally varying heat flux through the core mantle boundary (CMB). E.g. for the dynamo process in ancient Mars, a planetary scale CMB heat flux anomaly (Y10) reduces the rate of heat escaping the core in the north and increases it in the south, what concentrates the convection and induction into a single hemisphere. On the expense of rapid polarity inversions, it then seemed possible to increase the equatorial asymmetry far enough to correspond to the hemisphericity of the Martian crustal magnetisation. Within this study we parametrise horizontal extent, latitudinal position and amplitude of the anomaly in a rather comprehensive parameter study. Global flow symmetry properties are justified and used to quantify the influence of the heat flux anomalies and the action of the magnetic field. Our results suggest, that only rather large scale and strong amplitude anomalies are sufficient to induce magnetic fields matching the equatorial asymmetry of the crustal magnetisation pattern. Further all geometrically corresponding dynamo models show the problematic rapid polarity inversions which allow a strong and unidirectional magnetisation only when the crustal built-up time is on the order of the magnetic diffusion time (several kyrs). In summary, our results suggest that a single mantle hot spot positionend anywhere at the CMB will affect the core dynamics significantly only if its horizontal extent is on the order of the radius of the outer core. For Mars it seemes quite plausible, that the crustal magnetisation pattern was strongly influenced by post-dynamo demagnetisation processes rather than being magnetised by a geometrically corresponding internal dynamo field.

  1. Strain on the gastrocnemii and hamstrings affecting standing balance on an inclined plane in spastic cerebral palsy. A study using a geometric model.

    PubMed

    Suzuki, N; Mita, K; Watakabe, M; Akataki, K; Okagawa, T; Kimizuka, M

    1998-01-01

    The purpose of this study was to use an non-invasive method to determine whether strain on the gastrocnemii and hamstrings influences postural balance in spastic cerebral palsy (CP). Changes in alignment during standing posture with subjects positioned on a platform that was gradually inclined were measured in 10 normal children and 11 children with CP. The changes in postural alignment were plotted and geometric models used to determine the lines where the gastrocnemii and hamstrings were maximally stretched. In this way the relationship between postural alignment and the amount of strain on the gastrocnemii and hamstrings was investigated. On the inclined platform, which caused ankle joints to become dorsiflexed as the inclination angle increased, the gastrocnemii began to be strained and the hip joints began to be flexed (trunk bent forward) at the same time. In the children with CP, the gastrocnemii were more strained by smaller degrees of inclination. Furthermore, there was one child with CP whose hamstrings were also strained on the inclined platform. We confirmed that postural balance was affected by strain on the gastrocnemii and hamstrings.

  2. Cerebral Palsy (For Teens)

    MedlinePlus

    ... brain is affected and which parts of the body that section of the brain controls. If CP affects both arms and both legs, ... the case of spastic CP) or to help control seizures. And some might have special surgeries to keep their arms or legs straighter and more ... Coping With Cerebral Palsy Puberty can ...

  3. Preschoolers' mental rotation: sex differences in hemispheric asymmetry.

    PubMed

    Hahn, Nicola; Jansen, Petra; Heil, Martin

    2010-06-01

    Mental rotation performance has been found to produce one of the largest sex differences in cognition accompanied by sex differences in functional cerebral asymmetry. Although sex differences in mental rotation performance can be reliably demonstrated as early as age 5 years old, that is, long before puberty, no data exist as to whether preschooler's mental rotation performance is accompanied by sex differences in functional cerebral asymmetry. Based on the electrophysiological brain correlates of mental rotation, we observed a bilateral parietal brain activity for preschool boys whereas the preschool girls' brain activity was clearly lateralized toward the left hemisphere if and only if mental rotation was needed to solve the task. Thus, sex differences in functional cerebral asymmetry during mental rotation do not require hormonal changes that occur during puberty.

  4. The “black evil” affecting patients with diabetes: a case of rhino orbito cerebral mucormycosis causing Garcin syndrome

    PubMed Central

    Narayanan, Santhosh; Panarkandy, Geetha; Subramaniam, Gomathy; Radhakrishnan, Chandni; Thulaseedharan, NK; Manikath, Neeraj; Ramaswamy, Sreejith; Radhakrishnan, Suma; Ekkalayil, Danish

    2017-01-01

    Mucormycosis is a life-threatening infection affecting patients with diabetes. It is an angioinvasive disease often resistant to treatment with a debilitating course and high mortality. Here, we report a case of a 45 year old woman with type 2 diabetes mellitus who presented to us with history of right-sided ptosis and facial palsy, and subsequently developed loss of vision and palatal palsy. She was in diabetic ketoacidosis. Nervous system examination revealed involvement of right second, third, fourth, sixth, seventh, ninth, and tenth cranial nerves, suggestive of Garcin syndrome. The hard palate had been eroded with formation of black eschar. Computed tomography of paranasal sinuses revealed right maxillary and ethmoid sinusitis, with spread of inflammation to infratemporal fossa and parapharynygeal neck spaces. Debridement of sinus mucosa was done, and culture of the same yielded growth of rhizopus species. Histopathological examination of the tissue showed angioinvasion and fungal hyphae suggestive of mucormycosis. She was treated with amphotericin B, posaconazole, and periodic nasal sinus debridement, but her general condition worsened after 8 weeks due to secondary sepsis and she succumbed to death.

  5. Neptune's Southern Hemisphere

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This photograph of Neptune's southern hemisphere was taken by the narrow-angle camera on NASA's Voyager 2 when the spacecraft was 4.2 million km (2.6 million miles) from the planet. The smallest features that can be seen are 38 km (24 miles) across. The almond-shaped structure at the left is a large cloud system that has been seen for several weeks. Internal details in the feature have become increasingly apparent as Voyager 2 has approached. Systems with similar shapes in Jupiter's atmosphere rotate about their centers, rolling in the local winds that increase toward the south. However, the wispy nature of the white central clouds in this Neptunian feature make confirmation of the system's rotation difficult. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.

  6. Left Hemisphere Dysfunction and Left Hemisphere Overactivation in Schizophrenia

    ERIC Educational Resources Information Center

    Gur, Raquel E.

    1978-01-01

    Reports two studies relating schizophrenia to functional brain asymmetry. The first study found support for the hypothesis of left hemisphere dysfunction in schizophrenia, occurring at a rather early stage of information processing; the second study, using eye directionality as a measure of hemispheric activation, found that schizophrenics…

  7. The prisoners of despair: right hemisphere deficiency and suicide.

    PubMed

    Weinberg, I

    2000-12-01

    This paper presents an integrative approach to understanding of the inner experience of suicidal persons in terms of hemispheric asymmetry. The right hemisphere is involved in formation of polysemantic context. Polysemantic context is determined by multiple interconnections among its elements, while each concrete element bears the stamp of the whole context. Left hemisphere functioning leads to formation of monosemantic context. It is suggested that due to functional insufficiency of the right hemisphere the suicidal person demonstrates a compensatory shift to left hemisphere functioning. This shift manifests itself in reversed asymmetry of neurotransmitters, tendency to dissociation, alienated and negative perception of the body, lower sensitivity to pain, disintegration of self-representation, cognitive constriction, overly general nature of personal memories, difficulties in affect regulation as well as such personality traits as low openness to experience and personal constriction. This hypothesis raises a number of suggestions for future research.

  8. Water immersion to the femur level affects cerebral cortical activity in humans: functional near-infrared spectroscopy study.

    PubMed

    Sato, Daisuke; Onishi, Hideaki; Yamashiro, Koya; Iwabe, Tatsuya; Shimoyama, Yoshimitsu; Maruyama, Atsuo

    2012-04-01

    Water immersion is widely used in physiotherapy and may even improve the functional outcomes of hemiplegic patients after stroke. To investigate the cortical responses to water immersion, functional near-infrared spectroscopy (fNIRS) was used to measure cortical activations in the primary somatosensory area (S1), parietal association area (PAA), supplementary motor area (SMA), and primary motor area (M1). Nine healthy adult males were rested in a sitting position for 15 min with simultaneous measurements of fNIRS, blood pressure, and skin temperature. The fNIRS signal and other physiological parameters were measured under three conditions, the non-immersed condition (baseline control), as the immersion tank was filling with water (pouring water condition), and during sustained water immersion. Each condition lasted for 5 min. The water level was allowed to reach the femur, and during the experiment, room and water temperatures were maintained at 34°C. Oxygenated hemoglobin (oxyHb) concentrations in the S1, PAA, SMA, and M1 remained stable during baseline recording but gradually increased during water pouring and immersion. Significantly higher oxyHb levels were observed in S1 at 20 s after the onset of water immersion condition and in the PAA at 40 s. Subsequently, oxyHb levels in the SMA and M1 increased significantly 100 s after the onset of water immersion condition. In contrast, no significant changes in blood pressure, heart rate, or skin temperature were observed. Water immersion resulted in increased activity in both sensory and motor areas of cortex as measured by non-invasive fNIRS. Water immersion may enhance the efficacy of physical therapy by providing background activation to affected areas of the cortex, thereby enhancing signal processing and learning.

  9. Hypothalamic digoxin, hemispheric chemical dominance, and the tridosha theory.

    PubMed

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-05-01

    -potassium ATPase inhibition. Left hemispheric chemical dominance/Pitta state represents the reverse pattern with hypodigoxinemia and membrane sodium-potassium ATPase stimulation. The Vata state is the intermediate bihemispheric chemical dominant state. Ninety-five percent of the patients/individuals in the tridosha, pathological, and psychological groups were right-handed/left hemispheric dominant, however, their biochemical patterns were different--either left hemispheric chemical dominant or right hemispheric chemical dominant. Hemispheric chemical dominance/tridosha states had no correlation with cerebral dominance detected by handedness/dichotic listening test.

  10. Hemispheric asymmetries in the perceptual representations of words.

    PubMed

    Lincoln, Amy E; Long, Debra L; Swick, Diane; Larsen, Jary; Baynes, Kathleen

    2008-01-10

    The representation of words in sentences can involve the activation and integration of perceptual information. For example, readers who are asked to view pictures of objects relating to a word in a sentence are influenced by perceptual information in the sentence context-readers are faster to respond to a picture of a whole apple after reading, "There is an apple in the bag," than after reading, "There is an apple in the salad." The purpose of this study was to examine how the two cerebral hemispheres use perceptual information about words as a function of sentence context. Patients who had damage to the left or right hemisphere and age-matched control participants read sentences that described, but did not entail, the shape or state of an object. They then made recognition judgments to pictures that either matched or mismatched the perceptual form implied by the sentence. Responses and latencies were examined for a match effect -- faster and more accurate responses to pictures in the match than mismatch condition -- controlling for comprehension ability and lesion size. When comprehension ability and lesion size are properly controlled, left-hemisphere-damaged patients and control participants exhibited the expected match effect, whereas right-hemisphere-damaged participants showed no effect of match condition. These results are consistent with research implicating the right hemisphere in the representation of contextually relevant perceptual information.

  11. Europa Hemispherical Globes

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The images used for the base of this globe were chosen from coverage supplied by the Galileo solid-state imaging (SSI) camera and Voyager 1 and 2 spacecraft. The individual images were radiometrically calibrated and photometrically normalized using a Lunar-Lambert function with empirically derived values. A linear correction based on the statistics of all overlapping areas was then applied to minimize image brightness variations. The image data were selected on the basis of overall image quality, reasonable original input resolution (from 20 km/pixel for gap fill to as much as 200 m/pixel), and availability of moderate emission/incidence angles for topography. Although consistency was achieved where possible, different filters were included for global image coverage as necessary: clear/blue for Voyager 1 and 2, and clear, near-IR (757 nm), and green (559 nm) for Galileo SSI. Individual images were projected to a Sinusoidal Equal-Area projection at an image resolution of 500 m/pixel, and a final global mosaic was constructed in this same Sinusoidal projection.

    The global mosaic was then reprojected so that the entire surface of Europa is portrayed in a manner suitable for the production of a globe. A specialized program was used to create the 'flower petal' appearance of the images; the area of each petal from 0 to 75 degrees latitude is in the Transverse Mercator projection, and the area from 75 to 90 degrees latitude is in the Lambert Azimuthal Equal-Area projection. The projections for adjacent petals overlap by 2 degrees of longitude, so that some features are shown twice.

    Names shown on the globe are approved by the International Astronomical Union. The number, size, and placement of text were chosen for a 9-inch globe. A complete list of Europa nomenclature can be found at the Gazetteer of Planetary Nomenclature at http://planetarynames.wr.usgs.gov. The northern hemisphere is shown on the left, and the southern hemisphere is shown on the right.

  12. Callisto Hemispherical Globes

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The images used for the base of this globe were chosen from the best image quality and moderate resolution coverage supplied by Galileo SSI and Voyager 1 and 2 (Batson, 1987; Becker and others, 1998; Becker and others, 1999; Becker and others, 2001). The digital map was produced using Integrated Software for Imagers and Spectrometers (ISIS) (Eliason, 1997; Gaddis and others, 1997; Torson and Becker, 1997). The individual images were radiometrically calibrated and photometrically normalized using a Lunar-Lambert function with empirically derived values (McEwen, 1991; Kirk and others, 2000). A linear correction based on the statistics of all overlapping areas was then applied to minimize image brightness variations. The image data were selected on the basis of overall image quality, reasonable original input resolution (from 20 km/pixel for gap fill to as much as 150 m/pixel), and availability of moderate emission/incidence angles for topography. Although consistency was achieved where possible, different filters were included for global image coverage as necessary: clear for Voyager 1 and 2; clear and green (559 nm) for Galileo SSI. Individual images were projected to a Sinusoidal Equal-Area projection at an image resolution of 1.0 kilometer/pixel, and a final global mosaic was constructed in this same projection. The final mosaic was enhanced using commercial software. The global mosaic was then reprojected so that the entire surface of Callisto is portrayed in a manner suitable for the production of a globe. A specialized program was used to create the 'flower petal' appearance of the images; the area of each petal from 0 to 75 degrees latitude is in the Transverse Mercator projection, and the area from 75 to 90 degrees latitude is in the Lambert Azimuthal Equal-Area projection. The projections for adjacent petals overlap by 2 degrees of longitude, so that some features are shown twice. The northern hemisphere is shown on the left, and the southern hemisphere is

  13. Handedness is related to neural mechanisms underlying hemispheric lateralization of face processing

    NASA Astrophysics Data System (ADS)

    Frässle, Stefan; Krach, Sören; Paulus, Frieder Michel; Jansen, Andreas

    2016-06-01

    While the right-hemispheric lateralization of the face perception network is well established, recent evidence suggests that handedness affects the cerebral lateralization of face processing at the hierarchical level of the fusiform face area (FFA). However, the neural mechanisms underlying differential hemispheric lateralization of face perception in right- and left-handers are largely unknown. Using dynamic causal modeling (DCM) for fMRI, we aimed to unravel the putative processes that mediate handedness-related differences by investigating the effective connectivity in the bilateral core face perception network. Our results reveal an enhanced recruitment of the left FFA in left-handers compared to right-handers, as evidenced by more pronounced face-specific modulatory influences on both intra- and interhemispheric connections. As structural and physiological correlates of handedness-related differences in face processing, right- and left-handers varied with regard to their gray matter volume in the left fusiform gyrus and their pupil responses to face stimuli. Overall, these results describe how handedness is related to the lateralization of the core face perception network, and point to different neural mechanisms underlying face processing in right- and left-handers. In a wider context, this demonstrates the entanglement of structurally and functionally remote brain networks, suggesting a broader underlying process regulating brain lateralization.

  14. Handedness is related to neural mechanisms underlying hemispheric lateralization of face processing

    PubMed Central

    Frässle, Stefan; Krach, Sören; Paulus, Frieder Michel; Jansen, Andreas

    2016-01-01

    While the right-hemispheric lateralization of the face perception network is well established, recent evidence suggests that handedness affects the cerebral lateralization of face processing at the hierarchical level of the fusiform face area (FFA). However, the neural mechanisms underlying differential hemispheric lateralization of face perception in right- and left-handers are largely unknown. Using dynamic causal modeling (DCM) for fMRI, we aimed to unravel the putative processes that mediate handedness-related differences by investigating the effective connectivity in the bilateral core face perception network. Our results reveal an enhanced recruitment of the left FFA in left-handers compared to right-handers, as evidenced by more pronounced face-specific modulatory influences on both intra- and interhemispheric connections. As structural and physiological correlates of handedness-related differences in face processing, right- and left-handers varied with regard to their gray matter volume in the left fusiform gyrus and their pupil responses to face stimuli. Overall, these results describe how handedness is related to the lateralization of the core face perception network, and point to different neural mechanisms underlying face processing in right- and left-handers. In a wider context, this demonstrates the entanglement of structurally and functionally remote brain networks, suggesting a broader underlying process regulating brain lateralization. PMID:27250879

  15. Cerebral Lateralization and Its Effect on Drawing.

    ERIC Educational Resources Information Center

    Thomas, Yvonne A.; Thomas, Stephen B.

    1983-01-01

    Discusses the importance of both sides of the brain for the development of drawing skills but notes that the left brain can inhibit the action of the right brain. Provides a discussion of cerebral lateralization and child development. Suggests five drawing exercises to help develop hemispheric cooperation. (SB)

  16. Multiple fusiform cerebral aneurysms – case report

    PubMed Central

    Jaworska, Katarzyna; Dołowy, Joanna; Kuśmierska, Małgorzata; Kuniej, Tomasz; Jaźwiec, Przemysław

    2012-01-01

    Summary Background: A true aneurysym is a dilation of arterial lumen as a consequence of congenital or acquired abnormalities leading to a reduction of mechanical resistance of vascular wall, most commonly caused by its defected structure in the form of absence or weakening of the muscular and/or elastic layer. From the pathophysiological point of view, cerebral aneurysms can be classified as ‘saccular’ – most commonly occurring, and ‘other types’, including fusiform/dolichoectatic, dissecting, serpentine, posttraumatic, mycotic and giant aneurysms with or without intra-aneurysmal thrombosis. Case Report: We present a rare case of a patient with multiple fusiform dilations of cerebral vessels and giant fusiform aneurysm in supraclinoid segment of the internal carotid artery. The patient presented to hospital because of sudden, severe vertigo with nausea, impaired balance and disturbed vision. Vascular anomalies were detected on CT scanning without contrast. The diagnostic work-up was complemented by CT angiography, MRI and cerebral angiography. Conclusions: Aneurysm located within the intracranial arteries is one of the most common vascular defects of the brain. The number, size and location of aneurysms are highly variable. Aneurysms can have either supra- or infratentorial location, affecting a single or multiple arteries within one or both brain hemispheres. There is often a correlation between the location of the aneurysm and its etiology, as in case of so-called mirror-image aneurysms. Symmetrically located aneurysms may indicate a defect in vascular structure. Asymmetric location, as in the patient described above, is more likely due to acquired causes, mainly atherosclerosis, but also septic emboli or blood disorders. PMID:22802866

  17. Io's Kanehekili Hemisphere

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This color composite of Io, acquired by Galileo during its ninth orbit (C9) of Jupiter, shows the hemisphere of Io which is centered at longitude 52 degrees. The dark feature just to the lower right of the center of the disk is called Kanehekili. Named after an Hawaiian thunder god, Kanehekili contains two persistent high temperature hot spots and a 'new' active volcanic plume. NASA's Voyager spacecraft returned images of nine active plumes during its 1979 flyby of this dynamic satellite. To date, Galileo's plume monitoring observations have shown continued activity at four of those nine plume locations as well as new activity at six other locations.

    North is to the top of the picture which combines images acquired using violet, green, and near-infrared (756 micrometers) filters. The resolution is 21 kilometers per picture element. The images were taken on June 27, 1997 at a range of 1,033,000 kilometers by the solid state imaging (CCD) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  18. Europa's Leading Hemisphere

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image of Europa's leading hemisphere was obtained by the solid state imaging (CCD) system on board NASA's Galileo spacecraft during its seventh orbit of Jupiter. In the upper left part of the image is Tyre, a multi-ringed structure that may have formed as a result of an ancient impact. Also visible are numerous lineaments that extend for over 1000 kilometers. The limb, or edge, of Europa in this image can be used by scientists to constrain the radius and shape of the satellite. North is to the top of the picture and the sun illuminates the surface from the right. The image, centered at -40 latitude and 180 longitude, covers an area approximately 2000 by 1300 kilometers. The finest details that can be discerned in this picture are about 6.6 kilometers across. The images were taken on April 3, 1997 at 17 hours, 42 minutes, 19 seconds Universal Time when the spacecraft was at a range of 31,8628 kilometers.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  19. Where Were Those Rabbits? A New Paradigm to Determine Cerebral Lateralisation of Visuospatial Memory Function in Children

    ERIC Educational Resources Information Center

    Groen, Margriet A.; Whitehouse, Andrew J. O.; Badcock, Nicholas A.; Bishop, Dorothy V. M.

    2011-01-01

    In the majority of people, functional differences are observed between the two cerebral hemispheres: language production is typically subserved by the left hemisphere and visuospatial skills by the right hemisphere. The development of this division of labour is not well understood and lateralisation of visuospatial function has received little…

  20. Cortical Somatosensory Reorganization in Children with Spastic Cerebral Palsy: A Multimodal Neuroimaging Study

    PubMed Central

    Papadelis, Christos; Ahtam, Banu; Nazarova, Maria; Nimec, Donna; Snyder, Brian; Grant, Patricia Ellen; Okada, Yoshio

    2014-01-01

    Although cerebral palsy (CP) is among the most common causes of physical disability in early childhood, we know little about the functional and structural changes of this disorder in the developing brain. Here, we investigated with three different neuroimaging modalities [magnetoencephalography (MEG), diffusion tensor imaging (DTI), and resting-state fMRI] whether spastic CP is associated with functional and anatomical abnormalities in the sensorimotor network. Ten children participated in the study: four with diplegic CP (DCP), three with hemiplegic CP (HCP), and three typically developing (TD) children. Somatosensory (SS)-evoked fields (SEFs) were recorded in response to pneumatic stimuli applied to digits D1, D3, and D5 of both hands. Several parameters of water diffusion were calculated from DTI between the thalamus and the pre-central and post-central gyri in both hemispheres. The sensorimotor resting-state networks (RSNs) were examined by using an independent component analysis method. Tactile stimulation of the fingers elicited the first prominent cortical response at ~50 ms, in all except one child, localized over the primary SS cortex (S1). In five CP children, abnormal somatotopic organization was observed in the affected (or more affected) hemisphere. Euclidean distances were markedly different between the two hemispheres in the HCP children, and between DCP and TD children for both hemispheres. DTI analysis revealed decreased fractional anisotropy and increased apparent diffusion coefficient for the thalamocortical pathways in the more affected compared to less affected hemisphere in CP children. Resting-state functional MRI results indicated absent and/or abnormal sensorimotor RSNs for children with HCP and DCP consistent with the severity and location of their lesions. Our findings suggest an abnormal SS processing mechanism in the sensorimotor network of children with CP possibly as a result of diminished thalamocortical projections. PMID:25309398

  1. Inter-hemispheric integration of tactile-motor responses across body parts.

    PubMed

    Tamè, Luigi; Longo, Matthew R

    2015-01-01

    In simple detection tasks, reaction times (RTs) are faster when stimuli are presented to the visual field or side of the body ipsilateral to the body part used to respond. This advantage, the crossed-uncrossed difference (CUD), is thought to reflect inter-hemispheric interactions needed for sensorimotor information to be integrated between the two cerebral hemispheres. However, it is unknown whether the tactile CUD is invariant when different body parts are stimulated. The most likely structure mediating such processing is thought to be the corpus callosum (CC). Neurophysiological studies have shown that there are denser callosal connections between regions that represent proximal parts of the body near the body midline and more sparse connections for regions representing distal extremities. Therefore, if the information transfer between the two hemispheres is affected by the density of callosal connections, stimuli presented on more distal regions of the body should produce a greater CUD compared to stimuli presented on more proximal regions. This is because interhemispheric transfer of information from regions with sparse callosal connections will be less efficient, and hence slower. Here, we investigated whether the CUD is modulated as a function of the different body parts stimulated by presenting tactile stimuli unpredictably on body parts at different distances from the body midline (i.e., Middle Finger, Forearm, or Forehead of each side of the body). Participants detected the stimulus and responded as fast as possible using either their left or right foot. Results showed that the magnitude of the CUD was larger on the finger (~2.6 ms) and forearm (~1.8 ms) than on the forehead (≃0.9 ms). This result suggests that the interhemispheric transfer of tactile stimuli varies as a function of the strength of callosal connections of the body parts.

  2. Inter-hemispheric integration of tactile-motor responses across body parts

    PubMed Central

    Tamè, Luigi; Longo, Matthew R.

    2015-01-01

    In simple detection tasks, reaction times (RTs) are faster when stimuli are presented to the visual field or side of the body ipsilateral to the body part used to respond. This advantage, the crossed-uncrossed difference (CUD), is thought to reflect inter-hemispheric interactions needed for sensorimotor information to be integrated between the two cerebral hemispheres. However, it is unknown whether the tactile CUD is invariant when different body parts are stimulated. The most likely structure mediating such processing is thought to be the corpus callosum (CC). Neurophysiological studies have shown that there are denser callosal connections between regions that represent proximal parts of the body near the body midline and more sparse connections for regions representing distal extremities. Therefore, if the information transfer between the two hemispheres is affected by the density of callosal connections, stimuli presented on more distal regions of the body should produce a greater CUD compared to stimuli presented on more proximal regions. This is because interhemispheric transfer of information from regions with sparse callosal connections will be less efficient, and hence slower. Here, we investigated whether the CUD is modulated as a function of the different body parts stimulated by presenting tactile stimuli unpredictably on body parts at different distances from the body midline (i.e., Middle Finger, Forearm, or Forehead of each side of the body). Participants detected the stimulus and responded as fast as possible using either their left or right foot. Results showed that the magnitude of the CUD was larger on the finger (~2.6 ms) and forearm (~1.8 ms) than on the forehead (≃0.9 ms). This result suggests that the interhemispheric transfer of tactile stimuli varies as a function of the strength of callosal connections of the body parts. PMID:26124718

  3. Valles Marineris Hemisphere

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Mosaic composed of 102 Viking Orbiter images of Mars, covering nearly a full hemisphere of the planet (approximate latitude -55 to 60 degrees, longitude 30 to 130 degrees). The mosaic is in a point-perspective projection with a scale of about 1 km/pixel. The color variations have been enhanced by a factor of about two, and the large-scale brightness variations (mostly due to sun-angle variations) have been normalized by large-scale filtering. The center of the scene shows the entire Valles Marineris canyon system, over 3,000 km long and up to 8 km deep, extending from Noctis Labyrinthus, the arcuate system of graben to the west, to the chaotic terrain to the east. Bright white layers of material in the eastern canyons may consist of carbonates deposited in ancient lakes. Huge ancient river channels begin from the chaotic terrain and from north-central canyons and run north. Many of the channels flowed into a basin called Acidalia Planitia, which is the dark area in the extreme north of this picture. The Viking 1 landing site (Mutch Memorial Station) is located in Chryse Planitia, south of Acidalia Planitia. The three Tharsis volcanoes (dark red spots), each about 25 km high, are visible to the west. The large crater with two prominent rings located at the bottom of this image is named Lowell, after the Flagstaff astronomer. The images were acquired by Viking Orbiter 1 in 1980 during early northern summer on Mars (Ls = 70 degrees); the atmosphere was relatively dust-free. A variety of clouds appear as bright blue streaks and hazes, and probably consist of water ice. Long, linear clouds north of central Valles Marineris appear to emanate from impact craters.

  4. The Southern Hemisphere VLBI experiment

    SciTech Connect

    Preston, R.A.; Meier, D.L.; Louie, A.P.; Morabito, D.D.; Skjerve, L.; Slade, M.A.; Niell, A.E.; Wehrle, A.E.; Jauncey, D.L.; Tzioumis, A.K.; Haystack Observatory, Westford, MA; California Univ., Los Angeles; CSIRO, Div. of Radiophysics, Epping; Sydney Univ.; Manchester Victoria Univ., Jodrell Bank )

    1989-07-01

    Six radio telescopes were operated as the first Southern Hemisphere VLBI array in April and May 1982. Observations were made at 2.3 and 8.4 GHz. This array provided VLBI modeling and hybrid imaging of celestial radio sources in the Southern Hemisphere, high-accuracy VLBI geodesy between Southern Hemisphere sites, and subarcsecond radio astrometry of celestial sources south of declination -45 deg. The goals and implementation of the array are discussed, the methods of modeling and hybrid image production are explained, and the VLBI structure of the sources that were observed is summarized. 36 refs.

  5. The Propositional Structure of Discourse in the Two Cerebral Hemispheres

    ERIC Educational Resources Information Center

    Long, Debra L.; Baynes, Kathleen; Prat, Chantel S.

    2005-01-01

    Readers construct at least two interrelated representations when they comprehend a text: (a) a representation of the explicit ideas in a text and the relations among them (i.e., a propositional representation) and (b) a representation of the context or situation to which a text refers (i.e., a discourse model). In a recent study, Long and Baynes…

  6. Cerebral Economics: Resource Competition within but not Between Hemispheres.

    DTIC Science & Technology

    1981-06-01

    Creelman . 1967) to find separate exposure durations for the two types of matches that would yield 70% correct performance for both levels The procedure used...Braille and music reveals a functional basis Science. 1977, 197. 689-690 Taylor M M, & Creelman C D PEST Efficient estimates on probability functions

  7. Brain Responses and Information Processing III. Hemispheric Asymmetry in Event Related Potentials and Performance during Discrimination of Line Orientation and Velocity of Motion.

    DTIC Science & Technology

    1982-11-30

    dissertation, City University of New York, 1981. Molfese, D.L. Cerebral asymmetry in infants, children, and adults : Auditory evoked responses to speech and...Related Brain Potentials Introduction Cerebral hemispheric asymmetry has been extensively studied under many different experimental situations over the...in hemispheric asymmetry . Harris (1978) suggests that the male brain is lateralized with respect to linguistic-visuo-spatial functions (i.e., left

  8. Free form hemispherical shaped charge

    DOEpatents

    Haselman, L.C. Jr.

    1996-06-04

    A hemispherical shaped charge has been modified such that one side of the hemisphere is spherical and the other is aspherical allowing a wall thickness variation in the liner. A further modification is to use an elongated hemispherical shape. The liner has a thick wall at its pole and a thin wall at the equator with a continually decreasing wall thickness from the pole to the equator. The ratio of the wall thickness from the pole to the equator varies depending on liner material and HE shape. Hemispherical shaped charges have previously been limited to spherical shapes with no variations in wall thicknesses. By redesign of the basic liner thicknesses, the jet properties of coherence, stability, and mass distribution have been significantly improved. 8 figs.

  9. Free form hemispherical shaped charge

    DOEpatents

    Haselman, Jr., Leonard C.

    1996-01-01

    A hemispherical shaped charge has been modified such that one side of the hemisphere is spherical and the other is aspherical allowing a wall thickness variation in the liner. A further modification is to use an elongated hemispherical shape. The liner has a thick wall at its pole and a thin wall at the equator with a continually decreasing wall thickness from the pole to the equator. The ratio of the wall thickness from the pole to the equator varies depending on liner material and HE shape. Hemispherical shaped charges have previously been limited to spherical shapes with no variations in wall thicknesses. By redesign of the basic liner thicknesses, the jet properties of coherence, stability, and mass distribution have been significantly improved.

  10. Archimedes and the Magdeburg Hemispheres

    ERIC Educational Resources Information Center

    Hayn, Carl H.

    1975-01-01

    Weights suspended from a lever arm separate evacuated hemispheres allowing estimation of atmospheric pressure to within five percent of the barometric reading. An illustration and a reference to von Guericke's demonstration are provided. (GH)

  11. Brain Hemispheres and Thinking Styles.

    ERIC Educational Resources Information Center

    Gray, Esther Cappon

    1980-01-01

    The author reviews some research, particularly that of Roger Sperry, substantiating the existence of different thinking styles in the two brain hemispheres and the development of this differentiation in infancy and childhood. She draws some implications for elementary teaching. (SJL)

  12. Cerebral cortex: an MRI-based study of volume and variance with age and sex.

    PubMed

    Carne, Ross P; Vogrin, Simon; Litewka, Lucas; Cook, Mark J

    2006-01-01

    The aim of the present study was to examine quantitative differences in lobar cerebral cortical volumes in a healthy adult population. Quantitative volumetric MRI of whole brain, cerebral and cerebellar volumes was performed in a cross-sectional analysis of 97 normal volunteers, with segmented frontal, temporal, parietal and occipital cortical volumes measured in a subgroup of 60 subjects, 30 male and 30 female, matched for age and sex. The right cerebral hemisphere was larger than the left across the study group with a small (<1%) but significant difference in symmetry (P<0.001). No difference was found between volumes of right and left cerebellar hemispheres. Rightward cerebral cortical asymmetry (right larger than left) was found to be significant across all lobes except parietal. Males had greater cerebral, cerebellar and cerebral cortical lobar volumes than females. Larger male cerebral cortical volumes were seen in all lobes except for left parietal. Females had greater left parietal to left cerebral hemisphere and smaller left temporal to left cerebral hemisphere ratios. There was a mild reduction in cerebral volumes with age, more marked in males. This study confirms and augments past work indicating underlying structural asymmetries in the human brain, and provides further evidence that brain structures in humans are differentially sensitive to the effects of both age and sex.

  13. A Fluent Language Disorder Following Antepartum Left-Hemisphere Brain Injury.

    ERIC Educational Resources Information Center

    Feldman, Heidi M.; And Others

    1992-01-01

    This article describes the language development in a left-handed young child with a left middle cerebral artery infarction. Patterns of development observed between 36 and 60 months of age are described as a transient jargon or fluent aphasia possibly resulting from initial reliance on an uninjured right hemisphere. (Author/DB)

  14. Corpus Callosum Size is Linked to Dichotic Deafness and Hemisphericity, Not Sex or Handedness

    ERIC Educational Resources Information Center

    Morton, Bruce E.; Rafto, Stein E.

    2006-01-01

    Individuals differ in the number of corpus callosum (CC) nerve fibers interconnecting their cerebral hemispheres by about threefold. Early reports suggested that males had smaller CCs than females. This was often interpreted to support the concept that the male brain is more "lateralized" or "specialized," thus accounting for presumed male…

  15. The Role of Hemispheral Asymmetry and Regional Activity of Quantitative EEG in Children with Stuttering

    ERIC Educational Resources Information Center

    Ozge, Aynur; Toros, Fevziye; Comelekoglu, Ulku

    2004-01-01

    We investigated the role of delayed cerebral maturation, hemisphere asymmetry and regional differences in children with stuttering and healthy controls during resting state and hyperventilation, using conventional EEG techniques and quantitative EEG (QEEG) analysis. This cross-sectional case control study included 26 children with stuttering and…

  16. Lexical Competition is Enhanced in the Left Hemisphere: Evidence from Different Types of Orthographic Neighbors

    ERIC Educational Resources Information Center

    Perea, Manuel; Acha, Joana; Fraga, Isabel

    2008-01-01

    Two divided visual field lexical decision experiments were conducted to examine the role of the cerebral hemispheres in orthographic neighborhood effects. In Experiment 1, we employed two types of words: words with many substitution neighbors (high-"N") and words with few substitution neighbors (low-"N"). Results showed a facilitative effect of…

  17. Hemispheric Asymmetries in Processing L1 and L2 Idioms: Effects of Salience and Context

    ERIC Educational Resources Information Center

    Cieslicka, Anna B.; Heredia, Roberto R.

    2011-01-01

    This study investigates the contribution of the left and right hemispheres to the comprehension of bilingual figurative language and the joint effects of salience and context on the differential cerebral involvement in idiom processing. The divided visual field and the lexical decision priming paradigms were employed to examine the activation of…

  18. Music-induced changes in functional cerebral asymmetries.

    PubMed

    Hausmann, Markus; Hodgetts, Sophie; Eerola, Tuomas

    2016-04-01

    After decades of research, it remains unclear whether emotion lateralization occurs because one hemisphere is dominant for processing the emotional content of the stimuli, or whether emotional stimuli activate lateralised networks associated with the subjective emotional experience. By using emotion-induction procedures, we investigated the effect of listening to happy and sad music on three well-established lateralization tasks. In a prestudy, Mozart's piano sonata (K. 448) and Beethoven's Moonlight Sonata were rated as the most happy and sad excerpts, respectively. Participants listened to either one emotional excerpt, or sat in silence before completing an emotional chimeric faces task (Experiment 1), visual line bisection task (Experiment 2) and a dichotic listening task (Experiment 3 and 4). Listening to happy music resulted in a reduced right hemispheric bias in facial emotion recognition (Experiment 1) and visuospatial attention (Experiment 2) and increased left hemispheric bias in language lateralization (Experiments 3 and 4). Although Experiments 1-3 revealed an increased positive emotional state after listening to happy music, mediation analyses revealed that the effect on hemispheric asymmetries was not mediated by music-induced emotional changes. The direct effect of music listening on lateralization was investigated in Experiment 4 in which tempo of the happy excerpt was manipulated by controlling for other acoustic features. However, the results of Experiment 4 made it rather unlikely that tempo is the critical cue accounting for the effects. We conclude that listening to music can affect functional cerebral asymmetries in well-established emotional and cognitive laterality tasks, independent of music-induced changes in the emotion state.

  19. Hemispheric Lateralization of Resting-State Functional Connectivity of the Anterior Insula: Association with Age, Gender, and a Novelty-Seeking Trait

    PubMed Central

    Kann, Sarah; Zhang, Sheng; Manza, Peter; Leung, Hoi-Chung

    2016-01-01

    Abstract Resting-state functional connectivity (rsFC) is widely used to examine cerebral functional organization. The imaging literature has described lateralization of insula activations during cognitive and affective processing. Evidence appears to support a role of the right-hemispheric insula in attentional orientation to salient stimulus, interoception, and physiological arousal, and a role of the left-hemispheric insula in cognitive and affective control, as well as perspective taking. In this study, in a large data set of healthy adults, we examined lateralization of the rsFC of the anterior insula (AI) by computing a laterality index (LI) of connectivity with 54 regions from the Automated Anatomic Labeling atlas. At a corrected threshold (p < 0.001), the AI is left lateralized in connectivity with the dorsomedial prefrontal cortex, superior frontal gyrus, inferior frontal cortex, and posterior orbital gyrus and right lateralized in connectivity with the postcentral gyrus, supramarginal gyrus, and superior parietal lobule. In gender differences, women, but not men, showed right-lateralized connectivity to the thalamus. Furthermore, in a subgroup of participants assessed by the tridimensional personality questionnaire, novelty seeking is correlated with the extent of left lateralization of AI connectivity to the pallidum and putamen in men and with the extent of right lateralization of AI connectivity to the parahippocampal gyrus in women. These findings support hemispheric functional differentiation of the AI. PMID:27604154

  20. Hemispheric Lateralization of Resting-State Functional Connectivity of the Anterior Insula: Association with Age, Gender, and a Novelty-Seeking Trait.

    PubMed

    Kann, Sarah; Zhang, Sheng; Manza, Peter; Leung, Hoi-Chung; Li, Chiang-Shan R

    2016-11-01

    Resting-state functional connectivity (rsFC) is widely used to examine cerebral functional organization. The imaging literature has described lateralization of insula activations during cognitive and affective processing. Evidence appears to support a role of the right-hemispheric insula in attentional orientation to salient stimulus, interoception, and physiological arousal, and a role of the left-hemispheric insula in cognitive and affective control, as well as perspective taking. In this study, in a large data set of healthy adults, we examined lateralization of the rsFC of the anterior insula (AI) by computing a laterality index (LI) of connectivity with 54 regions from the Automated Anatomic Labeling atlas. At a corrected threshold (p < 0.001), the AI is left lateralized in connectivity with the dorsomedial prefrontal cortex, superior frontal gyrus, inferior frontal cortex, and posterior orbital gyrus and right lateralized in connectivity with the postcentral gyrus, supramarginal gyrus, and superior parietal lobule. In gender differences, women, but not men, showed right-lateralized connectivity to the thalamus. Furthermore, in a subgroup of participants assessed by the tridimensional personality questionnaire, novelty seeking is correlated with the extent of left lateralization of AI connectivity to the pallidum and putamen in men and with the extent of right lateralization of AI connectivity to the parahippocampal gyrus in women. These findings support hemispheric functional differentiation of the AI.

  1. Complementary hemispheric specialization for language production and visuospatial attention.

    PubMed

    Cai, Qing; Van der Haegen, Lise; Brysbaert, Marc

    2013-01-22

    Language production and spatial attention are the most salient lateralized cerebral functions, and their complementary specialization has been observed in the majority of the population. To investigate whether the complementary specialization has a causal origin (the lateralization of one function causes the opposite lateralization of the other) or rather is a statistical phenomenon (different functions lateralize independently), we determined the lateralization for spatial attention in a group of individuals with known atypical right hemispheric (RH) lateralization for speech production, based on a previous large-scale screening of left-handers. We show that all 13 participants with RH language dominance have left-hemispheric dominance for spatial attention, and all but one of 16 participants with left-hemispheric language dominance are RH dominant for spatial attention. Activity was observed in the dorsal fronto-parietal pathway of attention, including the inferior parietal sulcus and superior parietal lobule, the frontal eye-movement field, and the inferior frontal sulcus/gyrus, and these regions functionally colateralized in the hemisphere dominant for attention, independently of the side of lateralization. Our results clearly support the Causal hypothesis about the complementary specialization, and we speculate that it derives from a longstanding evolutionary origin. We also suggest that the conclusions about lateralization based on an unselected sample of the population and laterality assessment using coarse functional transcranial Doppler sonography should be interpreted with more caution.

  2. Left hemispheric advantage for numerical abilities in the bottlenose dolphin.

    PubMed

    Kilian, Annette; von Fersen, Lorenzo; Güntürkün, Onur

    2005-02-28

    In a two-choice discrimination paradigm, a bottlenose dolphin discriminated relational dimensions between visual numerosity stimuli under monocular viewing conditions. After prior binocular acquisition of the task, two monocular test series with different number stimuli were conducted. In accordance with recent studies on visual lateralization in the bottlenose dolphin, our results revealed an overall advantage of the right visual field. Due to the complete decussation of the optic nerve fibers, this suggests a specialization of the left hemisphere for analysing relational features between stimuli as required in tests for numerical abilities. These processes are typically right hemisphere-based in other mammals (including humans) and birds. The present data provide further evidence for a general right visual field advantage in bottlenose dolphins for visual information processing. It is thus assumed that dolphins possess a unique functional architecture of their cerebral asymmetries.

  3. Preschoolers' mental rotation of letters: Sex differences in hemispheric asymmetry.

    PubMed

    Hahn, Nicola; Jansen, Petra; Heil, Martin

    2010-12-01

    Adults' mental rotation performance has been found to produce one of the largest sex differences in cognition accompanied by sex differences in functional cerebral asymmetry. In this study sex differences in mental rotation of letters were investigated with children as young as five years. Based on the electrophysiological brain correlates of mental rotation, we observed a bilateral brain activity for preschool girls whereas the preschool boys' brain activity was clearly lateralized towards the right hemisphere if and only if mental rotation was needed to solve the task. At the same time, we did not find any sex differences in mental rotation speed or accuracy. Thus, sex differences in functional hemispheric asymmetry during mental rotation do not require hormonal changes that occur during puberty.

  4. Western Hemisphere Knowledge Partnerships

    NASA Astrophysics Data System (ADS)

    Malone, T. F.

    2001-05-01

    , and application of knowledge concerning the nature of -- and interaction among -- matter, living organisms, energy, information, and human behavior. This strategy calls for innovative partnerships among the physical, biological, health, and social sciences, engineering, and the humanities. New kinds of partnership must also be forged among academia, business and industry, governments, and nongovernmental organizations. Geophysicists can play an important role in these partnerships. A focus for these partnerships is to manage the individual economic productivity that drives both human development and global change. As world population approaches stability during the twenty-first century, individual economic productivity will be the critical link between the human and the natural systems on planet Earth. AGU is among a core group of individuals and institutions proposing Western Hemisphere Knowledge Partnerships (WHKP) to test the hypothesis that knowledge, broadly construed, is an important organizing principle in choosing a path into the future. The WHKP agenda includes: (1) life-long learning, (2) the health and resilience of natural ecosystems, (3) eco-efficiency in economic production and consumption, (4) extension of national income accounts, (5) environmentally benign sources of energy, (6) delivery of health care, (7) intellectual property rights, and (8) networks for action by local communities.Collaboratories and distance education technologies will be major tools. A panel of experts will explore this proposal.

  5. The "Creative Right Brain" Revisited: Individual Creativity and Associative Priming in the Right Hemisphere Relate to Hemispheric Asymmetries in Reward Brain Function.

    PubMed

    Aberg, Kristoffer Carl; Doell, Kimberly C; Schwartz, Sophie

    2016-09-20

    The idea that creativity resides in the right cerebral hemisphere is persistent in popular science, but has been widely frowned upon by the scientific community due to little empirical support. Yet, creativity is believed to rely on the ability to combine remote concepts into novel and useful ideas, an ability which would depend on associative processing in the right hemisphere. Moreover, associative processing is modulated by dopamine, and asymmetries in dopamine functionality between hemispheres may imbalance the expression of their implemented cognitive functions. Here, by uniting these largely disconnected concepts, we hypothesize that relatively less dopamine function in the right hemisphere boosts creativity by releasing constraining effects of dopamine on remote associations. Indeed, participants with reduced neural responses in the dopaminergic system of the right hemisphere (estimated by functional MRI in a reward task with positive and negative feedback), displayed higher creativity (estimated by convergent and divergent tasks), and increased associative processing in the right hemisphere (estimated by a lateralized lexical decision task). Our findings offer unprecedented empirical support for a crucial and specific contribution of the right hemisphere to creativity. More importantly our study provides a comprehensive view on potential determinants of human creativity, namely dopamine-related activity and associative processing.

  6. Fulminant cerebral infarction of anterior and posterior cerebral circulation after ascending type of facial necrotizing fasciitis.

    PubMed

    Lee, Jun Ho; Choi, Hui-Chul; Kim, Chulho; Sohn, Jong Hee; Kim, Heung Cheol

    2014-01-01

    Necrotizing fasciitis is a soft tissue infection that is characterized by extensive necrosis of the subcutaneous fat, neurovascular structures, and fascia. Cerebral infarction after facial necrotizing fasciitis has been rarely reported. A 61-year-old woman with diabetes was admitted with painful swelling of her right cheek. One day later, she was stuporous and quadriplegic. A computed tomographic scan of her face revealed right facial infection in the periorbital soft tissue, parotid, buccal muscle, and maxillary sinusitis. A computed tomographic scan of the brain revealed cerebral infarction in the right hemisphere, left frontal area, and both cerebellum. Four days later, she died from cerebral edema and septic shock. Involvement of the cerebral vasculature, such as the carotid or vertebral artery by necrotizing fasciitis, can cause cerebral infarction. Facial necrotizing fasciitis should be treated early with surgical treatment and the appropriate antibiotic therapy.

  7. A MEMS diamond hemispherical resonator

    NASA Astrophysics Data System (ADS)

    Bernstein, J. J.; Bancu, M. G.; Cook, E. H.; Chaparala, M. V.; Teynor, W. A.; Weinberg, M. S.

    2013-12-01

    In this paper we report the fabrication of hemispherical polycrystalline diamond resonators fabricated on a novel high-temperature glass substrate. The hemispherical resonator gyroscope is one of the most accurate and rugged of the mechanical gyroscopes, and can be operated in either rate or whole-angle mode due to its high degree of symmetry. A fabrication sequence for creating extremely symmetric 3D MEMS hemispheres is presented. Mode shapes and frequencies obtained with a laser vibrometer are shown, as well as curves of Q versus pressure, and the dependence of frequency on anchor size. Fundamental mode frequency matching to <0.1% in as-fabricated devices has been achieved, which is essential to gyroscope operation in whole-angle mode.

  8. Reaction time, cerebral blood flow, and heart rate responses in fibromyalgia: Evidence of alterations in attentional control.

    PubMed

    Reyes Del Paso, Gustavo A; Montoro, Casandra I; Duschek, Stefan

    2015-01-01

    The study investigated cerebral blood flow (CBF) and heart rate (HR) responses during a cued reaction time (RT) task in patients with fibromyalgia syndrome (FMS). CBF velocities in the middle (MCA) and anterior (ACA) cerebral arteries of both hemispheres were recorded in 46 patients and 32 healthy control participants using functional transcranial Doppler sonography (fTCD). Patients exhibited markedly longer RT than healthy participants. Group differences in CBF responses were mainly observed for both ACAs, with greater right hemispherical increases but lower left hemispherical increases in FMS patients than in healthy participants. HR deceleration around the imperative stimulus was more pronounced in healthy participants. RT was inversely related to increases in CBF in both right arteries and in the left ACA in the FMS group, but was positively associated with CBF responses in all four arteries in healthy participants. The magnitude of task-induced HR deceleration correlated negatively with RT in both groups. Patients' clinical pain severity was positively associated with RT and CBF responses; trait anxiety and insomnia were secondary negative predictors of CBF responses. The study provided evidence of a deficit in the alertness component of attention in FMS at behavioral, CBF, and autonomic levels. These results may be interpreted in terms of the neural efficiency hypothesis of intelligence (i.e., less efficient brain activation during cognition in FMS) and the interfering effect of clinical factors on cognition. Clinical factors such as pain, anxiety, and sleep disturbances can affect cognition in FMS by interfering with CBF adjustment to cognitive demands.

  9. Cerebral blood flow velocity changes during upright positioning in bed after acute stroke: an observational study

    PubMed Central

    Aries, Marcel J; Elting, Jan Willem; Stewart, Roy; De Keyser, Jacques; Kremer, Berry; Vroomen, Patrick

    2013-01-01

    Objectives National guidelines recommend mobilisation in bed as early as possible after acute stroke. Little is known about the influence of upright positioning on real-time cerebral flow variables in patients with stroke. We aimed to assess whether cerebral blood flow velocity (CBFV) changes significantly after upright positioning in bed in the acute stroke phase. Design Observational study. Participants 47 patients with acute ischaemic stroke measured in the subacute phase after symptom onset and 20 healthy controls. Primary and secondary outcome measures We recorded postural changes in bilateral transcranial Doppler (primary outcome) and simultaneously recorded near-infrared spectroscopy, end-tidal CO2, non-invasive blood pressure data and changes in neurological status (secondary outcomes). Methods Postures included the supine, half sitting (45°), sitting (70°) and Trendelenburg (−15°) positions. Using multilevel analyses, we compared postural changes between hemispheres, outcome groups (using modified Rankin Scale) as well as between patients and healthy controls. Results The mean patient age was 62±15 years and median National Institute of Health Stroke Scale score on admission was 7 (IQR 5–14). Mean proportional CBFV changes on sitting were not significantly different between healthy controls and affected hemispheres in patients with stroke. No significant differences were found between affected and unaffected stroke hemispheres and between patients with unfavourable and favourable outcomes. During upright positioning, no neurological worsening or improvement was observed in any of the patients. Conclusions No indications were found that upright positioning in bed in mild to moderately affected patients with stroke compromises flow and (frontal)oxygenation significantly during the subacute phase of stroke. Supine or Trendelenburg positioning does not seem to augment real-time flow variables. PMID:23945730

  10. Near-infrared spectroscopy and transcranial sonography to evaluate cerebral autoregulation in middle cerebral artery steno-occlusive disease.

    PubMed

    Oldag, Andreas; Neumann, Jens; Goertler, Michael; Hinrichs, Hermann; Heinze, Hans-Jochen; Kupsch, Andreas; Sweeney-Reed, Catherine M; Kopitzki, Klaus

    2016-11-01

    The measurement of autoregulatory delay by near-infrared spectroscopy (NIRS) has been proposed as an alternative technique to assess cerebral autoregulation, which is routinely assessed via transcranial Doppler sonography (TCD) in most centers. Comparitive studies of NIRS and TCD, however, are largely missing. We investigated whether cerebrovascular reserve (CVR), as assessed via TCD, correlates with the delay of the autoregulatory response to changes in arterial blood pressure (ABP) as assessed by NIRS, i.e., if impaired upstream vasomotor reactivity is reflected by downstream cortical autoregulation. Twenty patients with unilateral high-grade steno-occlusion of the middle cerebral artery (MCA) underwent bilateral multichannel NIRS of the cortical MCA distributions over a period of 6 min while breathing at a constant rate of 6 cycles/min to induce stable oscillations in ABP. The phase shift φ between ABP and cortical blood oxygenation was calculated as a measure of autoregulatory latency. In a subgroup of 13 patients, CO2 reactivity of the MCAs was determined by TCD to assess CVR in terms of normalized autoregulatory response (NAR). Mean phase shift between ABP and blood oxygenation was significantly increased over the hemisphere ipsilateral to the steno-occlusion (n = 20, p = 0.042). The interhemispheric difference Δφ in phase shift was significantly larger in patients with markedly diminished or exhausted CVR (NAR < 10) than in patients with normal NAR values (NAR ≥ 10) (p = 0.007). Within the MCA core distribution territory, a strong correlation existed between Δφ and CO2 reactivity of the affected MCA (n = 13, r = -0.78, p = 0.011). NIRS may provide an alternative or supplementary approach to evaluate cerebral autoregulation in risk assessment of ischemic events in steno-occlusive disease of cerebral arteries, especially in patients with insufficient bone windows for TCD.

  11. Lateralized free-association priming: implications for the hemispheric organization of semantic memory.

    PubMed

    Koivisto, M; Laine, M

    1995-01-01

    The organization of semantic memory in intact cerebral hemispheres was examined by a free-association priming task. Normal subjects studied a list of word pairs where the semantic relations were either coordinate (e.g. saw-axe) or locative (e.g. bear-forest). Priming of the word pairs was tested by presenting test cues (initial words of the pairs) to the left or to the right visual field. Results showed an interaction between visual field and word pair type, suggesting a qualitative difference in the semantic organization of the hemispheres. Specifically, the results support the view that coordinate relations are represented in both hemispheres whereas locative relations are represented mainly in the right hemisphere.

  12. Vocal Reaction Times of Stuttering Subjects to Tachistoscopically Presented Concrete and Abstract Words: A Closer Look at Cerebral Dominance and Language Processing.

    ERIC Educational Resources Information Center

    Rastatter, Michael P.; Dell, Carl

    1987-01-01

    The study investigated cerebral organization for visual language processing with 14 adult stutterers. Results showed the right hemisphere was superior for analyzing the concrete words while the left hemisphere was responsible for processing the abstract items suggesting some form of linguistic competition between the two hemispheres of this…

  13. Injury of the corticoreticular pathway in patients with proximal weakness following cerebral infarct: diffusion tensor tractography study.

    PubMed

    Do, Kyung Hee; Yeo, Sang Seok; Lee, Jun; Jang, Sung Ho

    2013-06-24

    The corticoreticular pathway (CRP) innervates mainly the proximal muscles of extremities. Identification of the CRP by diffusion tensor tractography (DTT) in the human brain has recently become possible. However, little is known about the relation between proximal weakness and injury of the CRP in stroke patients. In this study, we attempted to investigate the usefulness of DTT for elucidation of the relation between proximal motor weakness and injury of the CRP in patients with cerebral infarct. Among 247 consecutive patients with cerebral infarct, four hemiparetic patients who showed more severe weakness in proximal joints (shoulder and hip) than distal joints (finger and ankle) of the affected extremities were recruited for this study. Evaluation of motor function, DTT, and transcranial magnetic stimulation (TMS) for evaluation of the corticospinal tract state by analysis of the characteristics of the motor-evoked potential were performed at the early stage of cerebral infarct (mean: 17.0 days; range: 11-29). The integrity of the CST on DTT findings in the affected hemisphere was preserved in all four patients and TMS findings in terms of latency and amplitude showed within normal range (one patient) and partial injuries (three patients) of the corticospinal tract. By contrast, on DTT of the CRP in the affected hemispheres, we observed Wallerian degeneration in two patients and discontinuations at infarct level in two patients. The injury of the CRP appeared to attribute the proximal weakness of the shoulder and hip observed in these four patients. Therefore, DTT of the CRP would be useful for elucidating the relation between proximal weakness and injury of the CRP in patients with cerebral infarct.

  14. Cerebral Palsy (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Cerebral Palsy KidsHealth > For Parents > Cerebral Palsy A A A ... kids who are living with the condition. About Cerebral Palsy Cerebral palsy is one of the most common ...

  15. Cerebral palsy - resources

    MedlinePlus

    Resources - cerebral palsy ... The following organizations are good resources for information on cerebral palsy : National Institute of Neurological Disorders and Stroke -- www.ninds.nih.gov/disorders/cerebral_palsy/cerebral_palsy. ...

  16. Evidence for developmental programming of cerebral laterality in humans.

    PubMed

    Jones, Alexander; Osmond, Clive; Godfrey, Keith M; Phillips, David I W

    2011-02-16

    Adverse fetal environments are associated with depression, reduced cognitive ability and increased stress responsiveness in later life, but underlying mechanisms are unknown. Environmental pressures on the fetus, resulting from variations in placental function and maternal nutrition, health and stress might alter neurodevelopment, promoting the development of some brain regions over others. As asymmetry of cerebral activity, with greater right hemisphere activity, has been associated with psychopathology, we hypothesized that regional specialization during fetal life might be reflected persistently in the relative activity of the cerebral hemispheres. We tested this hypothesis in 140 healthy 8-9 year-old children, using tympanic membrane temperature to assess relative blood flow to the cerebral hemispheres at rest and following psychosocial stress (Trier Social Stress Test for Children). Their birth weight and placental weight had already been measured when their mothers took part in a previous study of pregnancy outcomes. We found that children who had a smaller weight at birth had evidence of greater blood flow to the right hemisphere than to the left hemisphere (r = -.09, P = .29 at rest; r = -.18, P = .04 following stress). This finding was strengthened if the children had a relatively low birth weight for their placental weight (r = -.17, P = .05 at rest; r = -.31, P = .0005 following stress). Our findings suggest that lateralization of cerebral activity is influenced persistently by early developmental experiences, with possible consequences for long-term neurocognitive function.

  17. Mutism following left hemisphere infarction.

    PubMed Central

    David, A S; Bone, I

    1984-01-01

    A case of mutism due to left hemisphere infarction is described. Recovery revealed mild motor dysphasia. Review of the literature showed that the case resembles aphemia but is unique by virtue of its duration, and the absence of associated apraxia and paresis. Images PMID:6210346

  18. Math Learning: The Two Hemispheres.

    ERIC Educational Resources Information Center

    Grow, Meda F.; Johnson, Norbert

    1983-01-01

    Discusses the duality of mental processes, learning styles and brain research (concerning brain growth, hemispheric specialization, and sex differences) as they apply to teaching mathematics. Discusses the implications of these topics as well as individual learning styles and basics-versus-creative school curricula for curriculum development. (WAS)

  19. Cerebral palsy.

    PubMed

    Colver, Allan; Fairhurst, Charles; Pharoah, Peter O D

    2014-04-05

    The syndrome of cerebral palsy encompasses a large group of childhood movement and posture disorders. Severity, patterns of motor involvement, and associated impairments such as those of communication, intellectual ability, and epilepsy vary widely. Overall prevalence has remained stable in the past 40 years at 2-3·5 cases per 1000 livebirths, despite changes in antenatal and perinatal care. The few studies available from developing countries suggest prevalence of comparable magnitude. Cerebral palsy is a lifelong disorder; approaches to intervention, whether at an individual or environmental level, should recognise that quality of life and social participation throughout life are what individuals with cerebral palsy seek, not improved physical function for its own sake. In the past few years, the cerebral palsy community has learned that the evidence of benefit for the numerous drugs, surgery, and therapies used over previous decades is weak. Improved understanding of the role of multiple gestation in pathogenesis, of gene environment interaction, and how to influence brain plasticity could yield significant advances in treatment of the disorder. Reduction in the prevalence of post-neonatal cerebral palsy, especially in developing countries, should be possible through improved nutrition, infection control, and accident prevention.

  20. Neuroendocrine hemisphere asymmetries: salivary cortisol secretion during lateralized viewing of emotion-related and neutral films.

    PubMed

    Wittling, W; Pflüger, M

    1990-11-01

    The study set out to examine whether the cerebral hemispheres differ in their ability to regulate cortisol secretion during emotion-related situations. One hundred twenty-three adult subjects were shown either an emotionally aversive or a neutral film in the left or right hemisphere by means of a technique for lateralizing visual input that allows prolonged viewing while permitting free ocular scanning. The film-related changes of cortisol secretion were determined by salivary cortisol radioimmunoassay. Right hemispheric viewing of the emotionally aversive film resulted in a significantly higher increase of cortisol secretion than left hemispheric viewing of the same film. No such differences were observed with respect to the neutral film. Comparing the effects of the two films separately for each hemisphere revealed that only the right hemisphere was able to respond neuroendocrinologically in a different manner to the emotional and the neutral film. Therefore, it is concluded that cortical regulation of cortisol secretion in emotion-related situations is under primary control of the right hemisphere. The potential implications of asymmetric control of cortisol secretion with respect to the pathogenesis of psychosomatic and immunological disorders are discussed.

  1. Magnitude of Cerebral Asymmetry at Rest: Covariation with Baseline Cardiovascular Activity

    ERIC Educational Resources Information Center

    Foster, Paul S.; Harrison, David W.

    2006-01-01

    The cerebral regulation of cardiovascular functioning varies along both a lateral and a longitudinal axis. The parasympathetic and sympathetic nervous systems are lateralized to the left and right cerebral hemispheres, respectively. Further, the frontal lobes are known to be inhibitory in nature, whereas the temporal lobes are excitatory. However,…

  2. Understanding the Dorsal and Ventral Systems of the Human Cerebral Cortex: Beyond Dichotomies

    ERIC Educational Resources Information Center

    Borst, Gregoire; Thompson, William L.; Kosslyn, Stephen M.

    2011-01-01

    Traditionally, characterizations of the macrolevel functional organization of the human cerebral cortex have focused on the left and right cerebral hemispheres. However, the idea of left brain versus right brain functions has been shown to be an oversimplification. We argue here that a top-bottom divide, rather than a left-right divide, is a more…

  3. Hemodynamic variability and cerebrovascular control after transient cerebral ischemia

    PubMed Central

    Allan, Philip D; Faulkner, James; O’Donnell, Terrence; Lanford, Jeremy; Wong, Lai-kin; Saleem, Saqib; Woolley, Brandon; Lambrick, Danielle; Stoner, Lee; Tzeng, Yu-Chieh

    2015-01-01

    We investigated if hemodynamic variability, cerebral blood flow (CBF) regulation, and their interrelationships differ between patients with transient ischemic attack (TIA) and controls. We recorded blood pressure (BP) and bilateral middle cerebral artery flow velocity (MCAv) in a cohort of TIA patients (n = 17), and age-matched controls (n = 15). Spontaneous fluctuations in BP and MCAv were characterized by spectral power analysis, and CBF regulation was assessed by wavelet phase synchronization analysis in the very low- (0.02–0.07 Hz), low- (0.07–0.20 Hz), and high-frequency (0.20–0.40 Hz) ranges. Furthermore, cerebrovascular CO2 reactivity was assessed as a second metric of CBF regulation by inducing hypercapnia with 8% CO2 inhalation followed by hyperventilation driven hypocapnia. We found that TIA was associated with higher BP power (group effect, P < 0.05), but not MCAv power (P = 0.11). CBF regulation (assessed by wavelet phase synchronization and CO2 reactivity) was intact in patients (all P ≥ 0.075) across both hemispheres (all P ≥ 0.51). Pooled data (controls and affected hemisphere of patients) showed that BP and MCAv power were positively correlated at all frequency ranges (R2 = 0.20–0.80, all P < 0.01). Furthermore, LF phase synchronization index was a significant determinant of MCAv power (P < 0.05), while VLF and HF phase synchronization index, and TIA were not (all P ≥ 0.50). These results indicate that CBF stability and control is maintained in TIA patients, but BPV is markedly elevated. BPV attenuation may be an important therapeutic strategy for enhancing secondary stroke prevention in patients who suffer a TIA. PMID:26537345

  4. Behavioral evidence for inter-hemispheric cooperation during a lexical decision task: a divided visual field experiment

    PubMed Central

    Perrone-Bertolotti, Marcela; Lemonnier, Sophie; Baciu, Monica

    2013-01-01

    HIGHLIGHTS The redundant bilateral visual presentation of verbal stimuli decreases asymmetry and increases the cooperation between the two hemispheres.The increased cooperation between the hemispheres is related to semantic information during lexical processing.The inter-hemispheric interaction is represented by both inhibition and cooperation. This study explores inter-hemispheric interaction (IHI) during a lexical decision task by using a behavioral approach, the bilateral presentation of stimuli within a divided visual field experiment. Previous studies have shown that compared to unilateral presentation, the bilateral redundant (BR) presentation decreases the inter-hemispheric asymmetry and facilitates the cooperation between hemispheres. However, it is still poorly understood which type of information facilitates this cooperation. In the present study, verbal stimuli were presented unilaterally (left or right visual hemi-field successively) and bilaterally (left and right visual hemi-field simultaneously). Moreover, during the bilateral presentation of stimuli, we manipulated the relationship between target and distractors in order to specify the type of information which modulates the IHI. Thus, three types of information were manipulated: perceptual, semantic, and decisional, respectively named pre-lexical, lexical and post-lexical processing. Our results revealed left hemisphere (LH) lateralization during the lexical decision task. In terms of inter-hemisphere interaction, the perceptual and decision-making information increased the inter-hemispheric asymmetry, suggesting the inhibition of one hemisphere upon the other. In contrast, semantic information decreased the inter-hemispheric asymmetry, suggesting cooperation between the hemispheres. We discussed our results according to current models of IHI and concluded that cerebral hemispheres interact and communicate according to various excitatory and inhibitory mechanisms, all which depend on specific

  5. Right Hemispheric Dominance in Processing of Unconscious Negative Emotion

    ERIC Educational Resources Information Center

    Sato, Wataru; Aoki, Satoshi

    2006-01-01

    Right hemispheric dominance in unconscious emotional processing has been suggested, but remains controversial. This issue was investigated using the subliminal affective priming paradigm combined with unilateral visual presentation in 40 normal subjects. In either left or right visual fields, angry facial expressions, happy facial expressions, or…

  6. Role of brain hemispheric dominance in anticipatory postural control strategies.

    PubMed

    Cioncoloni, David; Rosignoli, Deborah; Feurra, Matteo; Rossi, Simone; Bonifazi, Marco; Rossi, Alessandro; Mazzocchio, Riccardo

    2016-07-01

    Most of the cerebral functions are asymmetrically represented in the two hemispheres. Moreover, dexterity and coordination of the distal segment of the dominant limbs depend on cortico-motor lateralization. In this study, we investigated whether postural control may be also considered a lateralized hemispheric brain function. To this aim, 15 young subjects were tested in standing position by measuring center of pressure (COP) shifts along the anteroposterior axis (COP-Y) during dynamic posturography before and after continuous Theta Burst Stimulation (cTBS) intervention applied to the dominant or non-dominant M1 hand area as well as to the vertex. We show that when subjects were expecting a forward platform translation, the COP-Y was positioned significantly backward or forward after dominant or non-dominant M1 stimulation, respectively. We postulate that cTBS applied on M1 may have disrupted the functional connectivity between intra- and interhemispheric areas implicated in the anticipatory control of postural stability. This study suggests a functional asymmetry between the two homologous primary motor areas, with the dominant hemisphere playing a critical role in the selection of the appropriate postural control strategy.

  7. Cerebral Palsy Litigation

    PubMed Central

    Sartwelle, Thomas P.

    2015-01-01

    The cardinal driver of cerebral palsy litigation is electronic fetal monitoring, which has continued unabated for 40 years. Electronic fetal monitoring, however, is based on 19th-century childbirth myths, a virtually nonexistent scientific foundation, and has a false positive rate exceeding 99%. It has not affected the incidence of cerebral palsy. Electronic fetal monitoring has, however, increased the cesarian section rate, with the expected increase in mortality and morbidity risks to mothers and babies alike. This article explains why electronic fetal monitoring remains endorsed as efficacious in the worlds’ labor rooms and courtrooms despite being such a feeble medical modality. It also reviews the reasons professional organizations have failed to condemn the use of electronic fetal monitoring in courtrooms. The failures of tort reform, special cerebral palsy courts, and damage limits to stem the escalating litigation are discussed. Finally, the authors propose using a currently available evidence rule—the Daubert doctrine that excludes “junk science” from the courtroom—as the beginning of the end to cerebral palsy litigation and electronic fetal monitoring’s 40-year masquerade as science. PMID:25183322

  8. A new method for detecting cerebral hemorrhage in rabbits by magnetic inductive phase shift.

    PubMed

    Jin, Gui; Sun, Jian; Qin, Mingxin; Tang, Qinghua; Xu, Lin; Ning, Xu; Xu, Jia; Pu, Xianjie; Chen, Mingsheng

    2014-02-15

    Cerebral hemorrhage, which is an important clinical problem, is often monitored and studied using expensive devices, such as magnetic resonance imaging (MRI) and positron emission tomography (PET) that are unavailable in economically underdeveloped regions. Magnetic induction tomography (MIT) is a new type of non-contact, non-invasive, and low-cost detection technology, and exhibits prospects for wide application, especially for the detection of brain diseases. However, the previous studies on MIT have focused on laboratory models and rarely on in vivo applications because the induced signals produced by biological tissues are notably weak. Based on the symmetry between the two brain hemispheres and the fact that a local brain hemorrhage will not affect the contra-lateral hemisphere, a symmetric cancellation-type sensor detection system, which is characterized by one excitation coil and two receiving coils, was designed to improve the detection sensitivity of MIT. This method was subsequently used to detect the occurrence of cerebral hematomas in rabbits. The average phase drift induced by a 3-ml injection of autologous blood was 1.885°, which is a fivefold improvement compared with the traditional single excitation coil and single receiving coil method. The results indicate that this system has high sensitivity and anti-interference ability and high practical value.

  9. The Left-Right Hemisphere Model for Information Processing: Possible Implications for Education.

    ERIC Educational Resources Information Center

    Rubenzer, Ronald L.

    The paper, part of an all-day workshop, reviews research and theory on left-right hemisphere information processing and psychophysiological models on the functional organization of the brain. Hemisphericity is considered in terms of language, cognitive styles, role in education, verbal and non-verbal processing, affective concomitants, and…

  10. Hemispheric ultra-wideband antenna.

    SciTech Connect

    Brocato, Robert Wesley

    2006-04-01

    This report begins with a review of reduced size ultra-wideband (UWB) antennas and the peculiar problems that arise when building a UWB antenna. It then gives a description of a new type of UWB antenna that resolves these problems. This antenna, dubbed the hemispheric conical antenna, is similar to a conventional conical antenna in that it uses the same inverted conical conductor over a ground plane, but it also uses a hemispheric dielectric fill in between the conductive cone and the ground plane. The dielectric material creates a fundamentally new antenna which is reduced in size and much more rugged than a standard UWB conical antenna. The creation of finite-difference time domain (FDTD) software tools in spherical coordinates, as described in SAND2004-6577, enabled this technological advance.

  11. Cerebral hyperperfusion syndrome after intracranial stenting of the middle cerebral artery

    PubMed Central

    Maramattom, Boby Varkey

    2016-01-01

    Cerebral hyperperfusion syndrome (CHS) is a rare complication following cerebral revascularization. It presents with ipsilateral headache, seizures, and intracerebral hemorrhage. It has mostly been described following extracranial carotid endarterectomy and stenting and it is very unusual after intracranial stenting. A 71-year-old man with a stuttering stroke was taken up for a cerebral angiogram (digital subtraction angiography), which showed a dissection of the distal left middle cerebral artery. This was recanalized with a solitaire AB stent. After 12 h, the patient developed a right hemiplegia and aphasia. Computed tomography brain showed two discrete intracerebral hematomas in the left hemisphere. This is the first reported case of CHS following intracranial stenting from India. PMID:27829722

  12. Structure of the cerebral cortex in men and women.

    PubMed

    Rabinowicz, Theodore; Petetot, Jean MacDonald-Comber; Gartside, Peter S; Sheyn, David; Sheyn, Tony; de, Courten-MyersGabrielleM

    2002-01-01

    Expanding previous studies of human cerebral cortical sexual dimorphism showing higher neuronal densities in males, we investigated whether gender differences also exist in the extent of neuropil, size of neuronal somata, and volumes of astrocytes. This histo-morphometric study includes select autopsy brains of 6 males and 5 females, 12 to 24 yr old. In each brain, 86 defined loci were analyzed for cortical thickness, neuronal and astrocytic (8 loci) density (stereological counts), and neuronal and astrocytic (8 loci) soma size, enabling calculations of neuropil and astrocytic volumes. The female group showed significantly larger neuropil volumes than males, whereas neuronal soma size and astrocytic volumes did not differ. The expanded data confirmed higher neuronal densities in males than in females without a gender difference in cortical thickness. These findings indicate that fundamental gender differences exist in the structure of the human cerebral cortex, with more numerous, smaller neuronal units in men and fewer, larger ones in women; they may underlie gender-specific abilities and susceptibilities to disease affecting the neocortex. Laterality differences between the sexes were restricted to neuronal soma size showing significantly larger values in the female group in the left hemisphere. This gender difference may support female's right-handedness, language advantage, and tendency for bilateral activation patterns.

  13. Flow past 2-D Hemispherical Rigid Canopies

    NASA Astrophysics Data System (ADS)

    Carnasciali, Maria-Isabel

    2013-11-01

    The flow past a 2-dimensional rigid hemispherical shape is investigated using PIV. Flow field measurements and images were generated with the use of a Thermoflow® apparatus. Results of this study are compared to prior work (APS DFD 2012 Session E9.00003) which employed CFD to investigate the flow in the near wake of hemispherical parachutes. The various sized gaps/open areas were positioned at distinct locations. The work presented here is part of a larger research project to investigate flow fields in deceleration devices and parachutes. Understanding the pitch-stability of parachutes is essential for accurate design and implementation of these deceleration devices but they present a difficult system to analyze. The flexibility of the parachute fabric results in large variations in the parachute geometry leading to complex fluid-structure interactions. Such flow, combined with flow through gaps and open areas, has been postulated to shed alternating vortices causing pitching/oscillations of the canopy. The results presented provide some insight into which geometric features affect vortex shedding and may enable the redesign of the baseline parachute to minimize instabilities.

  14. Hemispheric superiority for processing a mirror image.

    PubMed

    Garren, R B; Gehlsen, G M

    1981-04-01

    39 adult subjects were administered a test using tachistoscopic half-field presentations to determine hemispheric dominance and a mirror-tracing task to determine if an hemispheric superiority exists for processing a mirror-image. The results indicate superiority of the nondominant hemisphere for this task.

  15. Hemispheric Specialization in Normal and Disabled Readers.

    ERIC Educational Resources Information Center

    Newell, David; Rugel, Robert P.

    1981-01-01

    Degree of hemispheric specialization in 32 normal and 32 disabled readers (9 to 12 years old) was evaluated using a linguistic task and a musical task. While normals demonstrated hemispheric specialization on these tasks in the expected directions, disabled readers showed a right hemisphere deficit. (Author)

  16. Emotional Television Scenes and Hemispheric Specialization.

    ERIC Educational Resources Information Center

    Reeves, Byron; And Others

    1989-01-01

    Examines hemispheric differences in cortical arousal as a function of positive and negative emotional television scenes. Finds that (1) the processing of emotional content is hemispherically asymmetric; and (2) negative material produced greater cortical arousal in the right hemisphere and positive material greater arousal in the left. (MS)

  17. Brain Hemispheric Functions and the Native American.

    ERIC Educational Resources Information Center

    Ross, Allen Chuck

    1982-01-01

    Uses brain research conducted by Dr. Roger Sperry to show that traditional Native Americans are more dominant in right hemisphere thinking, setting them apart from a modern left hemisphere-oriented society (especially emphasized in schools). Describes some characteristics of Native American thinking that illustrate a right hemisphere orientation…

  18. Hemispheric Laterality in Music and Math

    ERIC Educational Resources Information Center

    Szirony, Gary Michael; Burgin, John S.; Pearson, L. Carolyn

    2008-01-01

    Hemispheric laterality may be a useful concept in teaching, learning, training, and in understanding more about human development. To address this issue, a measure of hemispheric laterality was compared to musical and mathematical ability. The Human Information Processing Survey (HIPS) instrument, designed to measure hemispheric laterality, was…

  19. Right Hemisphere Dominance in Visual Statistical Learning

    ERIC Educational Resources Information Center

    Roser, Matthew E.; Fiser, Jozsef; Aslin, Richard N.; Gazzaniga, Michael S.

    2011-01-01

    Several studies report a right hemisphere advantage for visuospatial integration and a left hemisphere advantage for inferring conceptual knowledge from patterns of covariation. The present study examined hemispheric asymmetry in the implicit learning of new visual feature combinations. A split-brain patient and normal control participants viewed…

  20. Awake right hemisphere brain surgery.

    PubMed

    Hulou, M Maher; Cote, David J; Olubiyi, Olutayo I; Smith, Timothy R; Chiocca, E Antonio; Johnson, Mark D

    2015-12-01

    We report the indications and outcomes of awake right hemispheric brain surgery, as well as a rare patient with crossed aphasia. Awake craniotomies are often performed to protect eloquent cortex. We reviewed the medical records for 35 of 96 patients, in detail, who had awake right hemisphere brain operations. Intraoperative cortical mapping of motor and/or language function was performed in 29 of the 35 patients. A preoperative speech impairment and left hand dominance were the main indicators for awake right-sided craniotomies in patients with right hemisphere lesions. Four patients with lesion proximity to eloquent areas underwent awake craniotomies without cortical mapping. In addition, one patient had a broncho-pulmonary fistula, and another had a recent major cardiac procedure that precluded awake surgery. An eloquent cortex representation was identified in 14 patients (48.3%). Postoperatively, seven of 17 patients (41.1%) who presented with weakness, experienced improvements in their motor functions, 11 of 16 (68.7%) with seizures became seizure-free, and seven of nine (77.7%) with moderate to severe headaches and one of two with a visual field deficit improved significantly. There were also improvements in speech and language functions in all patients who presented with speech difficulties. A right sided awake craniotomy is an excellent option for left handed patients, or those with right sided cortical lesions that result in preoperative speech impairments. When combined with intraoperative cortical mapping, both speech and motor function can be well preserved.

  1. Cerebral Malaria.

    PubMed

    Marsden, P D; Bruce-Chwatt, L J

    1975-01-01

    Cerebral malaria is an acute diffuse encephalopathy associated only with Plasmodium falciparum. It is probably a consequence of the rapid proliferation of the parasites in the body of man in relation to red cell invasion, and results in stagnation of blood flow in cerebralcapillaries with thromobotic occlusion of large numbers of cerebral capillaries. The subsequent cerebral pathology is cerebral infarction with haemorrhage and cerebral oedema. The wide prevalence of P. falciparum in highly endemic areas results in daily challenges to patients from several infected mosquitoes. It is thus important to understand the characteristics of P. falciparum, since this is one of the most important protozoan parasites of man and severe infection from it constitutes one of the few real clinical emergencies in tropical medicine. One of the more important aspects of the practice of medicine in the tropics is to establish a good understanding of the pattern of medical practice in that area. This applies to malaria as well as to other diseases. The neophyte might be somewhat surprised to learn, for example that an experienced colleague who lives in a holoendemic malarious area such as West Africa, sees no cerebral malaria. But the explanation is simple when the doctor concerned has a practice which involves treating adults only. Cerebral malaria is rare in adults, because in highly endemic areas, by the age of 1 year most of the infants in a group under study have already experienced their first falciparum infection. By the time they reach adult life, they have a solid immunity against severe falciparum infections. In fact, "clinical malaria" could occur in such a group under only two circumstances: 1) in pregnancy, a patent infection with P. falciparum might develop, probably due to an IgG drain across the placenta to the foetus;2) in an individual who has constantly taken antimalarials and who may have an immunity at such a low level that when antimalarial therapy is interrupted

  2. Can secondary degeneration accelerate the formation of neurofibrillary tangles? A case of hemispheric infarction showing asymmetric degeneration of the substantia nigra, red nuclei, inferior olivary nuclei and dentate nuclei with concomitant changes of progressive supranuclear palsy.

    PubMed

    Matsumoto, R; Oda, M; Arai, N; Shin, T; Hayashi, M

    1999-02-01

    A case of hemispheric infarction involving the territory of the right middle cerebral artery and the thalamus showed conspicuous asymmetric degeneration in the substantia nigra, red nuclei, inferior olivary nuclei and dentate nuclei with concomitant changes of progressive supranuclear palsy (PSP). The right substantia nigra and red nucleus showed loss of neurons and proliferation of astrocytes. The right olivary nucleus was hypertrophic, while the neuronal loss and astrocytosis in the dentate nucleus were predominant on the contralateral side. Modified Gallyas-Braak staining revealed the extensive distribution of neurofibrillary tangles (NFTs), threads and intraglial argyrophilic structures in the globus pallidus, subthalamic nuclei, cerebral cortex and dentate nuclei, as well as in the affected brain stem nuclei, with a distinct predominance on the affected side. In this case, the one-sided predominance of the extended degeneration in these brain stem and cerebellar areas is considered, in addition to the PSP changes, to be due to secondary retrograde degeneration via the nigrostriatal and dentato-rubro-thalamic pathways following the hemispheric infarction, and to also be the result of disruption of the dentato-olivary fiber connections. In addition, because of the predominant distribution of NFTs on the more degenerated side, it is surmised that the formation of NFTs may be accelerated by secondary degeneration.

  3. A two-hit mechanism causes cerebral cavernous malformations: complete inactivation of CCM1, CCM2 or CCM3 in affected endothelial cells

    PubMed Central

    Pagenstecher, Axel; Stahl, Sonja; Sure, Ulrich; Felbor, Ute

    2009-01-01

    Cavernous vascular malformations occur with a frequency of 1:200 and can cause recurrent headaches, seizures and hemorrhagic stroke if located in the brain. Familial cerebral cavernous malformations (CCMs) have been associated with germline mutations in CCM1/KRIT1, CCM2 or CCM3/PDCD10. For each of the three CCM genes, we here show complete localized loss of either CCM1, CCM2 or CCM3 protein expression depending on the inherited mutation. Cavernous but not adjacent normal or reactive endothelial cells of known germline mutation carriers displayed immunohistochemical negativity only for the corresponding CCM protein but not for the two others. In addition to proving loss of function at the protein level, our data are the first to demonstrate endothelial cell mosaicism within cavernous tissues and provide clear pathogenetic evidence that the endothelial cell is the cell of disease origin. PMID:19088124

  4. A two-hit mechanism causes cerebral cavernous malformations: complete inactivation of CCM1, CCM2 or CCM3 in affected endothelial cells.

    PubMed

    Pagenstecher, Axel; Stahl, Sonja; Sure, Ulrich; Felbor, Ute

    2009-03-01

    Cavernous vascular malformations occur with a frequency of 1:200 and can cause recurrent headaches, seizures and hemorrhagic stroke if located in the brain. Familial cerebral cavernous malformations (CCMs) have been associated with germline mutations in CCM1/KRIT1, CCM2 or CCM3/PDCD10. For each of the three CCM genes, we here show complete localized loss of either CCM1, CCM2 or CCM3 protein expression depending on the inherited mutation. Cavernous but not adjacent normal or reactive endothelial cells of known germline mutation carriers displayed immunohistochemical negativity only for the corresponding CCM protein but not for the two others. In addition to proving loss of function at the protein level, our data are the first to demonstrate endothelial cell mosaicism within cavernous tissues and provide clear pathogenetic evidence that the endothelial cell is the cell of disease origin.

  5. Hemispheric lateralization of singing after intracarotid sodium amylobarbitone1

    PubMed Central

    Gordon, H. W.; Bogen, J. E.

    1974-01-01

    Hemispheric lateralization of singing was investigated in patients who had transient hemiplegia after intracarotid injection of sodium amylobarbitone. It was found that after right carotid injection singing was markedly deficient, whereas speech remained relatively intact. Songs were sung in a monotone, devoid of correct pitch rendering; rhythm was much less affected. By contrast, singing was less disturbed than speech after left carotid injection. The observations indicated a double dissociation; the right hemisphere contributed more for singing, whereas the left demonstrated its usual dominance for speech. A model is proposed that encompasses audible stimuli as well as tactual or visual into a scheme of functional lateralization wherein the right hemisphere specializes in processing a complete, time-independent stimulus configuration and the left in a series of successive, time-dependent units. PMID:4844140

  6. Spatial orientation in man: effects of left, right, and bilateral posterior cerebral lesions.

    PubMed

    Ratcliff, G; Newcombe, F

    1973-06-01

    Men with chronic, penetrating missile wounds of the brain were examined with two `spatial' tasks: a visually-guided stylus maze and a locomotor map-reading task. Men whose lesions involved the posterior part of the right cerebral hemisphere were significantly worse than those with left posterior lesions at stylus maze-learning. On the locomotor task, however, a highly significant deficit was found in the group of men with bilateral posterior cerebral lesions, while those with unilateral lesions of either hemisphere and those with bilateral frontal lesions were unimpaired. The contributions of the two cerebral hemispheres to the analysis of spatial information are discussed in the light of these results and it is suggested that, while the right hemisphere has a special role in the perception of space, it does not bear exclusive responsibility for the maintenance of spatial orientation.

  7. Cerebral laterality differences in handedness: a mental rotation study with NIRS.

    PubMed

    Shimoda, Nobuaki; Takeda, Kotaro; Imai, Itsuki; Kaneko, Junichiroh; Kato, Hiroyuki

    2008-01-03

    Spatial cognition is right-hemisphere dominant in right-handers, but hemispheric laterality in left-handers is not fully understood. Using near-infrared spectroscopy, we compared cerebral activations in the frontal and parietal lobes during a mental rotation task between seven healthy right-handed and seven healthy left-handed women. Cerebral laterality during the spatial cognition task was evaluated as balance in the extent of activation areas between the two cerebral hemispheres, using the right-hemispheric dominance index (RI). RIs of right-handers showed right-hemispheric dominance (RI>0) in both frontal (RI=0.31+/-0.25) and parietal (RI=0.28+/-0.37) lobes, while left-handers showed slight left-hemispheric dominance (RI<0) in both frontal (RI=-0.13+/-0.18) and parietal (RI=-0.22+/-0.22) lobes. The left-handers exhibited significantly larger amplitudes of activation at the channels overlying the left-superior parietal lobule, whereas the right-handers did not show such amplitude differences. These findings suggest a difference in cerebral hemispheric laterality for spatial cognition between left- and right-handers.

  8. Cerebral vascular findings in PAPA syndrome: cerebral arterial vasculopathy or vasculitis and a posterior cerebral artery dissecting aneurysm.

    PubMed

    Khatibi, Kasra; Heit, Jeremy J; Telischak, Nicholas A; Elbers, Jorina M; Do, Huy M

    2015-06-24

    A young patient with PAPA (pyogenic arthritis, pyoderma gangrenosum, and acne) syndrome developed an unusual cerebral arterial vasculopathy/vasculitis (CAV) that resulted in subarachnoid hemorrhage from a ruptured dissecting posterior cerebral artery (PCA) aneurysm. This aneurysm was successfully treated by endovascular coil sacrifice of the affected segment of the PCA. The patient made an excellent recovery with no significant residual neurologic deficit.

  9. Cerebral vascular findings in PAPA syndrome: cerebral arterial vasculopathy or vasculitis and a posterior cerebral artery dissecting aneurysm.

    PubMed

    Khatibi, Kasra; Heit, Jeremy J; Telischak, Nicholas A; Elbers, Jorina M; Do, Huy M

    2016-08-01

    A young patient with PAPA (pyogenic arthritis, pyoderma gangrenosum, and acne) syndrome developed an unusual cerebral arterial vasculopathy/vasculitis (CAV) that resulted in subarachnoid hemorrhage from a ruptured dissecting posterior cerebral artery (PCA) aneurysm. This aneurysm was successfully treated by endovascular coil sacrifice of the affected segment of the PCA. The patient made an excellent recovery with no significant residual neurologic deficit.

  10. The Effect of the 4MAT Method (Learning Styles and Brain Hemispheres) of Instruction on Achievement in Mathematics

    ERIC Educational Resources Information Center

    Tatar, Enver; Dikici, Ramazan

    2009-01-01

    The purpose of this study was to determine the efficiency of 4MAT method of instruction in which learning style and cerebral hemispheres are taken into account in teaching the binary operation and its properties in mathematics. The sample of this study comprised 58 ninth grade students in two separate classes in a high school. One of the classes…

  11. Prolonged cerebral "luxury perfusion" after removal of a convexity meningioma.

    PubMed

    Lunsford, L D; Selker, R G

    1979-04-01

    Following total removal of a convexity meningioma, serial computerized tomographic scans disclosed massive hemispheric contrast enhancement compatible with "luxury perfusion". Maximum enhancement occurred one month following the operation and resolved two months postoperatively. Luxury perfusion appeared to be associated with slowly resolving cerebral edema.

  12. The Relationships Between Cerebral Dominance and Different Mental Abilities.

    ERIC Educational Resources Information Center

    Reynolds, Carl; Bartek, Elmer

    Using a sample of 77 10th grade boys, the researchers studied the relationships between the mental abilities measured by the Differential Aptitude Tests and cerebral dominance (CD: the extent to which one hemisphere of the brain dominates the other for control of behavior). The surprise finding was that CD was negatively related to spatial…

  13. Cerebral Laterality Effects in the Dual Processing of Prose.

    ERIC Educational Resources Information Center

    Dean, Raymond S.

    1984-01-01

    The degree to which concreteness of prose material presented in an auditory fashion would interact with learners' lateral preference under different right hemispheric presentation conditions was investigated with 96 adults. Subjects recalled a greater number of ideas when the passage was concrete. Abstractness interacted with cerebral dominance.…

  14. Acute cerebral vascular accident associated with hyperperfusion.

    PubMed

    Soin, J S; Burdine, J A

    1976-01-01

    Cerebral radionuclide angiography can demonstrate decreased or normal radioactivity in the affected region during the arterial phase in patients who have sustained a cerebral vascular accident and thus enhances the diagnostic specificity of the static brain image. In an occasional patient, however, a seemingly paradoxical pattern of regional hyperperfusion with a return to normal or subnormal perfusion following the acute phase has been observed. This phenomenon, called "luxury perfusion," has been defined using intra-arterial 133Xe for semiquantitative cerebral blood flow measurements and should be kept in mind as a potentially misleading cerebral imaging pattern.

  15. Hemispheric specialization in quantification processes.

    PubMed

    Pasini, M; Tessari, A

    2001-01-01

    Three experiments were carried out to study hemispheric specialization for subitizing (the rapid enumeration of small patterns) and counting (the serial quantification process based on some formal principles). The experiments consist of numerosity identification of dot patterns presented in one visual field, with a tachistoscopic technique, or eye movements monitored through glasses, and comparison between centrally presented dot patterns and lateralized tachistoscopically presented digits. Our experiments show left visual field advantage in the identification and comparison tasks in the subitizing range, whereas right visual field advantage has been found in the comparison task for the counting range.

  16. Genomic causes of multiple cerebral cavernous malformations in a Japanese population.

    PubMed

    Tsutsumi, Satoshi; Ogino, Ikuko; Miyajima, Masakazu; Ikeda, Tomomi; Shindo, Noriko; Yasumoto, Yukimasa; Ito, Masanori; Arai, Hajime

    2013-05-01

    Cerebral cavernous malformation (CCM) is a hamartomatous vascular disease affecting the central nervous system. A fraction of CCM are thought to arise in association with genomic mutations in the cerebral cavernous malformation 1 (CCM1) (KRIT1), CCM2 (MGC4607), and CCM3 (PDCD10) genes. In the present study, 18 Japanese patients with multiple CCM (10 with familial type and eight with sporadic type), underwent genomic analysis for CCM1, CCM2 and CCM3 mutations with blood samples and surgical specimens. MRI showed CCM in the cerebral hemisphere in 17 patients, the cerebellum in 10, the brainstem in 10 and the spinal cord in eight. CCM2 mutations were the most prominent, followed by CCM1 and CCM3. CCM1, CCM2 and CCM3 mutations were not identified in seven patients. Among the 10 patients with familial CCM, CCM1, CCM2 and CCM3 mutations were found in two, three and one patient, respectively, whereas four patients lacked these mutations. Among the eight patients with sporadic CCM, these mutations were found in one, three, and one patients, respectively, whereas three patients lacked these mutations. Most of the patients had a stable course during the follow-up period. Genomic mutations other than CCM1, CCM2 and CCM3 may be frequent in patients with multiple CCM in the Japanese population.

  17. Dominance of the Unaffected Hemisphere Motor Network and Its Role in the Behavior of Chronic Stroke Survivors

    PubMed Central

    Bajaj, Sahil; Housley, Stephen N.; Wu, David; Dhamala, Mukesh; James, G. A.; Butler, Andrew J.

    2016-01-01

    Balance of motor network activity between the two brain hemispheres after stroke is crucial for functional recovery. Several studies have extensively studied the role of the affected brain hemisphere to better understand changes in motor network activity following stroke. Very few studies have examined the role of the unaffected brain hemisphere and confirmed the test–retest reliability of connectivity measures on unaffected hemisphere. We recorded blood oxygenation level dependent functional magnetic resonance imaging (fMRI) signals from nine stroke survivors with hemiparesis of the left or right hand. Participants performed a motor execution task with affected hand, unaffected hand, and both hands simultaneously. Participants returned for a repeat fMRI scan 1 week later. Using dynamic causal modeling (DCM), we evaluated effective connectivity among three motor areas: the primary motor area (M1), the premotor cortex (PMC) and the supplementary motor area for the affected and unaffected hemispheres separately. Five participants’ manual motor ability was assessed by Fugl-Meyer Motor Assessment scores and root-mean square error of participants’ tracking ability during a robot-assisted game. We found (i) that the task performance with the affected hand resulted in strengthening of the connectivity pattern for unaffected hemisphere, (ii) an identical network of the unaffected hemisphere when participants performed the task with their unaffected hand, and (iii) the pattern of directional connectivity observed in the affected hemisphere was identical for tasks using the affected hand only or both hands. Furthermore, paired t-test comparison found no significant differences in connectivity strength for any path when compared with one-week follow-up. Brain-behavior linear correlation analysis showed that the connectivity patterns in the unaffected hemisphere more accurately reflected the behavioral conditions than the connectivity patterns in the affected hemisphere

  18. Dominance of the Unaffected Hemisphere Motor Network and Its Role in the Behavior of Chronic Stroke Survivors.

    PubMed

    Bajaj, Sahil; Housley, Stephen N; Wu, David; Dhamala, Mukesh; James, G A; Butler, Andrew J

    2016-01-01

    Balance of motor network activity between the two brain hemispheres after stroke is crucial for functional recovery. Several studies have extensively studied the role of the affected brain hemisphere to better understand changes in motor network activity following stroke. Very few studies have examined the role of the unaffected brain hemisphere and confirmed the test-retest reliability of connectivity measures on unaffected hemisphere. We recorded blood oxygenation level dependent functional magnetic resonance imaging (fMRI) signals from nine stroke survivors with hemiparesis of the left or right hand. Participants performed a motor execution task with affected hand, unaffected hand, and both hands simultaneously. Participants returned for a repeat fMRI scan 1 week later. Using dynamic causal modeling (DCM), we evaluated effective connectivity among three motor areas: the primary motor area (M1), the premotor cortex (PMC) and the supplementary motor area for the affected and unaffected hemispheres separately. Five participants' manual motor ability was assessed by Fugl-Meyer Motor Assessment scores and root-mean square error of participants' tracking ability during a robot-assisted game. We found (i) that the task performance with the affected hand resulted in strengthening of the connectivity pattern for unaffected hemisphere, (ii) an identical network of the unaffected hemisphere when participants performed the task with their unaffected hand, and (iii) the pattern of directional connectivity observed in the affected hemisphere was identical for tasks using the affected hand only or both hands. Furthermore, paired t-test comparison found no significant differences in connectivity strength for any path when compared with one-week follow-up. Brain-behavior linear correlation analysis showed that the connectivity patterns in the unaffected hemisphere more accurately reflected the behavioral conditions than the connectivity patterns in the affected hemisphere. Above

  19. Hand movements with a phase structure and gestures that depict action stem from a left hemispheric system of conceptualization.

    PubMed

    Helmich, I; Lausberg, H

    2014-10-01

    The present study addresses the previously discussed controversy on the contribution of the right and left cerebral hemispheres to the production and conceptualization of spontaneous hand movements and gestures. Although it has been shown that each hemisphere contains the ability to produce hand movements, results of left hemispherically lateralized motor functions challenge the view of a contralateral hand movement production system. To examine hemispheric specialization in hand movement and gesture production, ten right-handed participants were tachistoscopically presented pictures of everyday life actions. The participants were asked to demonstrate with their hands, but without speaking what they had seen on the drawing. Two independent blind raters evaluated the videotaped hand movements and gestures employing the Neuropsychological Gesture Coding System. The results showed that the overall frequency of right- and left-hand movements is equal independent of stimulus lateralization. When hand movements were analyzed considering their Structure, the presentation of the action stimuli to the left hemisphere resulted in more hand movements with a phase structure than the presentation to the right hemisphere. Furthermore, the presentation to the left hemisphere resulted in more right and left-hand movements with a phase structure, whereas the presentation to the right hemisphere only increased contralateral left-hand movements with a phase structure as compared to hand movements without a phase structure. Gestures that depict action were primarily displayed in response to stimuli presented in the right visual field than in the left one. The present study shows that both hemispheres possess the faculty to produce hand movements in response to action stimuli. However, the left hemisphere dominates the production of hand movements with a phase structure and gestures that depict action. We therefore conclude that hand movements with a phase structure and gestures that

  20. Cerebral Disorders of Calves.

    PubMed

    Dore, Vincent; Smith, Geof

    2017-03-01

    Neurologic diseases of the cerebrum are relatively common in cattle. In calves, the primary cerebral disorders are polioencephalomalacia, meningitis, and sodium toxicity. Because diagnostic testing is not always readily available, the practitioner must often decide on a course of treatment based on knowledge of the likely disease, as well as his or her own clinical experience. This is particularly true with neurologic diseases in which the prognosis is often poor and euthanasia may be the most humane outcome. This article reviews the most common diseases affecting the cerebrum of calves with a focus on pathophysiology, diagnosis, and treatment.

  1. Fish oil supplementation associated with decreased cellular degeneration and increased cellular proliferation 6 weeks after middle cerebral artery occlusion in the rat.

    PubMed

    Pascoe, Michaela C; Howells, David W; Crewther, David P; Carey, Leeanne M; Crewther, Sheila G

    2015-01-01

    Anti-inflammatory long-chain omega-3 polyunsaturated fatty acids (n-3-LC-PUFAs) are both neuroprotective and have antidepressive effects. However the influence of dietary supplemented n-3-LC-PUFAs on inflammation-related cell death and proliferation after middle cerebral artery occlusion (MCAo)-induced stroke is unknown. We have previously demonstrated that anxiety-like and hyperactive locomotor behaviors are reduced in n-3-LC-PUFA-fed MCAo animals. Thus in the present study, male hooded Wistar rats were exposed to MCAo or sham surgeries and examined behaviorally 6 weeks later, prior to euthanasia and examination of lesion size, cell death and proliferation in the dentate gyrus, cornu ammonis region of the hippocampus of the ipsilesional hemispheres, and the thalamus of the ipsilesional and contralesional hemispheres. Markers of cell genesis and cell degeneration in the hippocampus or thalamus of the ipsilesional hemisphere did not differ between surgery and diet groups 6 weeks post MCAo. Dietary supplementation with n-3-LC-PUFA decreased cell degeneration and increased cell proliferation in the thalamic region of the contralesional hemisphere. MCAo-associated cell degeneration in the hippocampus and thalamus positively correlated with anxiety-like and hyperactive locomotor behaviors previously reported in these animals. These results suggest that anti-inflammatory n-3-LC-PUFA supplementation appears to have cellular protective effects after MCAo in the rat, which may affect behavioral outcomes.

  2. Acute effects of electroconvulsive therapy on regional cerebral blood flow (rCBF) in psychiatric disorders

    SciTech Connect

    Prohovnik, I.; Alderson, P.O.; Sackheim, H.A.; Decina, P.; Kahn, D.

    1984-01-01

    Electroconvulsive therapy (ECT) is frequently used in the treatment of major depression and other psychiatric disorders; its mechanism of action is not established, but previous evidence suggests that it is associated with postictal metabolic suppression. The authors have used measurements of rCBF as an index of cortical metabolic activity to study the acute effects of ECT. Measurements of rCBF were made in 32 cortical regions in 10 patients (pts) following one minute breathing of Xe-133 (5mCi/L); the measurements were performed 30min before and 50min after ECT. Bilateral ECT was administered to six pts (five diagnosed as major depressives and one schizophrenic) and unilateral ECT to four (all diagnosed as unipolar or bipolar affective disorder). The total rCBF material consists of 52 measurements in these pts, made before and after 16 bilateral and 10 unilateral treatments. ECT was found to cause significant reduction of rCBF. Mean hemispheric flows (using the Initial Slope Index to measure grey-matter flow) were reduced by about 5% in both hemispheres following bilateral treatment. Unilateral treatment caused a 9% reduction of flow in the treated hemisphere, but only 2% contralaterally. Regional patterns of flow decreases also differed between the two treatment modes: bilateral frontal reductions were found after bilateral treatment, whereas unilateral ECT caused a widespread flow reduction in the treated hemisphere, and almost no effect contralaterally. These results suggest that rCBF studies are useful for assessing ECT, and indicate that the acute cerebral effects of ECT vary with the mode of treatment.

  3. Mechanisms of recovery from aphasia: evidence from serial xenon 133 cerebral blood flow studies

    SciTech Connect

    Knopman, D.S.; Rubens, A.B.; Selnes, O.A.; Klassen, A.C.; Meyer, M.W.

    1984-06-01

    In 21 patients who suffered aphasia resulting from left hemisphere ischemic infarction, the xenon 133 inhalation cerebral blood flow technique was used to measure cerebral blood flow within 3 months and 5 to 12 months after stroke. In addition to baseline measurements, cerebral blood flow measurements were also carried out while the patients were performing purposeful listening. In patients with incomplete recovery of comprehension and left posterior temporal-inferior parietal lesions, greater cerebral blood flow occurred with listening in the right inferior frontal region in the late studies than in the early studies. In patients with nearly complete recovery of comprehension and without left posterior temporal-inferior parietal lesions, early listening studies showed diffuse right hemisphere increases in cerebral blood flow. Later listening studies in this latter patient group showed greater cerebral blood flow in the left posterior temporal-inferior parietal region. The study provides evidence for participation of the right hemisphere in language comprehension in recovering aphasics, and for later return of function in left hemisphere regions that may have been functionally impaired early during recovery.

  4. Homotopic Language Reorganization in the Right Hemisphere after Early Left Hemisphere Injury

    ERIC Educational Resources Information Center

    Tivarus, Madalina E.; Starling, Sarah J.; Newport, Elissa L.; Langfitt, John T.

    2012-01-01

    To determine the areas involved in reorganization of language to the right hemisphere after early left hemisphere injury, we compared fMRI activation patterns during four production and comprehension tasks in post-surgical epilepsy patients with either left (LH) or right hemisphere (RH) speech dominance (determined by Wada testing) and healthy…

  5. Silent ischemic lesion laterality in asymptomatic internal carotid artery stenosis relates to reduced cerebral vasoreactivity

    PubMed Central

    Isozaki, Makoto; Kataoka, Hiroharu; Fukushima, Kazuhito; Ishibashi-Ueda, Hatsue; Yamada, Naoaki; Iida, Hidehiro; Iihara, Koji

    2017-01-01

    Background: We investigated the relationship between silent ischemic lesions, defined as hyperintense lesions on T2-weighted magnetic resonance imaging scans of brain white matter and cerebral hemodynamics (baseline cerebral blood flow and cerebral vasoreactivity). Methods: Between January 2007 and December 2012, 61 patients with asymptomatic internal carotid artery stenosis were evaluated for asymptomatic silent ischemic lesions, acute infarction, and cerebral hemodynamics. Patients were divided into 2 groups based on silent ischemic lesion distribution; the Symmetry group (n = 34) included patients who showed symmetrical distribution of lesions (or had no lesions), and the Asymmetry group (n = 27) included patients with a greater number of lesions in the ipsilateral than that in the contralateral hemisphere. The Asymmetry group was further divided into Internal (n = 15) and External (n = 12) types. Results: Two External-type patients (17%) showed spotty asymptomatic acute infarction in the ipsilateral hemisphere. There were no significant differences in patient characteristics, histopathological findings, vascular risk factors, or cerebral blood flow values between the groups. The mean cerebral vasoreactivity value in the ipsilateral hemisphere for the Internal type was 13.0 ± 15.2% (range: −11.4% to 41.6%), which was significantly lower than values of the contralateral hemisphere (36.7 ± 20.8%; range: 3.9% to 75.7%; P <.01) and ipsilateral hemispheres of the other groups (P <.01). Conclusions: The finding that increased ipsilateral asymmetrical silent ischemic lesions correlated with cerebral vasoreactivity reduction may help predict the risk of cerebral infarction in patients with asymptomatic internal carotid artery stenosis. PMID:28217385

  6. Cerebral Tissue Oxygenation during Immediate Neonatal Transition and Resuscitation

    PubMed Central

    Pichler, Gerhard; Schmölzer, Georg M.; Urlesberger, Berndt

    2017-01-01

    This article provides a review of cerebral tissue oxygenation during immediate transition after birth in human neonates. Recommended routine monitoring, especially if resuscitation is needed, during this period includes arterial oxygen saturation and heart rate measured by pulse oximetry and electrocardiogram. However, there is increasing interest to monitor in addition with near-infrared spectroscopy (NIRS) the oxygenation of the brain. There is a different pattern of increase between cerebral tissue oxygenation and arterial oxygen saturation during the immediate transition, with cerebral tissue oxygenation reaching a plateau faster than arterial oxygen saturation. Differences can be explained, since cerebral tissue oxygenation is not only affected by arterial oxygen saturation but also by cerebral blood flow, hemoglobin content, and cerebral oxygen consumption. Normal values have already been established for different devices, gestational ages, and modes of delivery in neonates without any medical support. Cerebral hypoxia during immediate transition might cause brain damage. In preterm neonates with cerebral hemorrhage evolving in the first week after birth, the cerebral tissue oxygenation is already lower in the first minutes after birth compared to preterm neonates without cerebral hemorrhage. Using cerebral NIRS in combination with intervention guidelines has been shown to reduce the burden of cerebral hypoxia in preterm neonates. Cerebral tissue oxygenation during immediate transition seems to have an impact on outcome, whereby NIRS monitoring is feasible and has the advantage of continuous, non-invasive recording. The impact of NIRS monitoring and interventions on short- and long-term outcomes still need to be evaluated. PMID:28280719

  7. Cerebral Tissue Oxygenation during Immediate Neonatal Transition and Resuscitation.

    PubMed

    Pichler, Gerhard; Schmölzer, Georg M; Urlesberger, Berndt

    2017-01-01

    This article provides a review of cerebral tissue oxygenation during immediate transition after birth in human neonates. Recommended routine monitoring, especially if resuscitation is needed, during this period includes arterial oxygen saturation and heart rate measured by pulse oximetry and electrocardiogram. However, there is increasing interest to monitor in addition with near-infrared spectroscopy (NIRS) the oxygenation of the brain. There is a different pattern of increase between cerebral tissue oxygenation and arterial oxygen saturation during the immediate transition, with cerebral tissue oxygenation reaching a plateau faster than arterial oxygen saturation. Differences can be explained, since cerebral tissue oxygenation is not only affected by arterial oxygen saturation but also by cerebral blood flow, hemoglobin content, and cerebral oxygen consumption. Normal values have already been established for different devices, gestational ages, and modes of delivery in neonates without any medical support. Cerebral hypoxia during immediate transition might cause brain damage. In preterm neonates with cerebral hemorrhage evolving in the first week after birth, the cerebral tissue oxygenation is already lower in the first minutes after birth compared to preterm neonates without cerebral hemorrhage. Using cerebral NIRS in combination with intervention guidelines has been shown to reduce the burden of cerebral hypoxia in preterm neonates. Cerebral tissue oxygenation during immediate transition seems to have an impact on outcome, whereby NIRS monitoring is feasible and has the advantage of continuous, non-invasive recording. The impact of NIRS monitoring and interventions on short- and long-term outcomes still need to be evaluated.

  8. Communicating with the non-dominant hemisphere: Implications for neurological rehabilitation☆

    PubMed Central

    de Oliveira, Fabricio Ferreira; Correia Marin, Sheilla de Medeiros; Ferreira Bertolucci, Paulo Henrique

    2013-01-01

    Aphasic syndromes usually result from injuries to the dominant hemisphere of the brain. Despite the fact that localization of language functions shows little interindividual variability, several brain areas are simultaneously activated when language tasks are undertaken. Mechanisms of language recovery after brain injury to the dominant hemisphere seem to be relatively stereotyped, including activations of perilesional areas in the acute phase and of homologues of language areas in the non-dominant hemisphere in the subacute phase, later returning to dominant hemisphere activation in the chronic phase. Plasticity mechanisms reopen the critical period of language development, more specifically in what leads to disinhibition of the non-dominant hemisphere when brain lesions affect the dominant hemisphere. The non-dominant hemisphere plays an important role during recovery from aphasia, but currently available rehabilitation therapies have shown limited results for efficient language improvement. Large-scale randomized controlled trials that evaluate well-defined interventions in patients with aphasia are needed for stimulation of neuroplasticity mechanisms that enhance the role of the non-dominant hemisphere for language recovery. Ineffective treatment approaches should be replaced by more promising ones and the latter should be evaluated for proper application. The data generated by such studies could substantiate evidence-based rehabilitation strategies for patients with aphasia. PMID:25206418

  9. Hemispheric asymmetries in memory processes as measured in a false recognition paradigm.

    PubMed

    Westerberg, Carmen E; Marsolek, Chad J

    2003-01-01

    Although memory differs in important ways between the left and right cerebral hemispheres, the nature of these differences remains controversial. We examined this issue in two experiments using a false memory paradigm that allowed novel tests of two theories that have not been assessed in a common paradigm previously. Lists of semantically related words (e.g., bed, rest, wake...), all highly associated to one "critical" word (e.g., sleep), were presented auditorily during a study phase. Memory for both the related words and the critical words was measured in a subsequent old/new recognition test using divided-visual-field word presentations. The most important results were that the ability to correctly reject previously unpresented words was greater when test items were presented to the right visual field/left hemisphere (RVF/LH) than to the left visual field/right hemisphere (LVF/RH) and that participants were more confident in correctly rejecting unpresented words when test items were presented to the RVF/LH than to the LVF/RH. Results were in line with the theory that associative activation of semantic information is restricted in the left hemisphere but diffuse in the right; however, these results contrasted with the theory that memory traces are interpretive in the left hemisphere but veridical in the right. A potential resolution to the seemingly contradictory theories of asymmetries in memory processing is briefly discussed.

  10. Hemispheric laterality assessment with dichotic digits testing in dyslexia and auditory processing disorder.

    PubMed

    Iliadou, Vassiliki; Kaprinis, Stergios; Kandylis, Dimitrios; Kaprinis, George St

    2010-03-01

    One of the widely used tests to evaluate functional asymmetry of cerebral hemispheres is the dichotic listening test with the usually prevailing right ear advantage. The current study aims at assessing hemispheric laterality in an adult sample of individuals with dyslexia, with auditory processing disorder (APD), and adults experiencing comorbidity of the two mentioned disorders against a control group with normal hearing and absence of learning disabilities. Results exhibit a right hemispheric dominance for the control and APD group, a left hemispheric dominance for the group diagnosed with both dyslexia and APD, and absence of dominance for the dyslexia group. Assessment of laterality was repeatable and produced stable results, indicating a true deficit. A component of auditory processing, specifically the auditory performance in competing acoustic signals, seems to be deficient in all three groups, and laterality of hemispheric functions influenced at least for auditory-language stimuli in the two of the three groups, one being adults with dyslexia and the other being adults with comorbidity of dyslexia and APD.

  11. Intravenous administration of pravastatin immediately after middle cerebral artery occlusion reduces cerebral oedema in spontaneously hypertensive rats.

    PubMed

    Mariucci, Giuseppina; Taha, Elena; Tantucci, Michela; Spaccatini, Cristiano; Tozzi, Alessandro; Ambrosini, Maria Vittoria

    2011-06-25

    3-hydroxy-3-methyl-glutaryl-coenzyme-A (HMG-CoA) reductase inhibitors (statins) have been shown to protect against ischemic stroke by mechanisms that are independent of lowering serum cholesterol levels. In this study we investigated the potential neuroprotective effect of a single i.v. treatment with four increasing doses of pravastatin on permanent occlusion of middle cerebral artery (MCAo) in spontaneously hypertensive rats. Pravastatin was given 10 min after MCAo and its effect was determined 24 h later. Treatment results were evaluated in terms of infarct volume, homolateral hemisphere oedema, glial fibrillary acid (GFAP), vimentin (Vim) and endothelial NO synthase (eNOS) immunoreactivity and TUNEL positivity. Cerebral levels of eNOS were measured by western blot analysis. Pravastatin did not reduce cerebral infarct while it mitigated homolateral hemisphere oedema in a dose-dependent manner with respect to controls. No differences among groups were found regarding GFAP and Vim immunoreactivity and TUNEL positivity. Instead, pravastatin-treated animals presented a more marked cerebral eNOS immunoreactivity as compared with controls. In agreement with immunohistochemistry, immunoblot revealed dose-dependent increases in cerebral levels of eNOS in pravastatin rats. Our data confirm statin neuroprotection in cerebral ischemia. In particular, it is of great interest that a single i.v. Pravastatin administration reduced cerebral oedema by upregulating eNOS expression/activity. This, by increasing vascular NO bioavailability, could have produced proximal vasodilation and contributed to reducing perfusional deficit. It is worthy stressing how important the anti-oedema action is that pravastatin seems to exert. Indeed, cerebral oedema, when widespread and beyond limits of physiological compensation, causes endocranic hypertension and additional cerebral damage over time.

  12. Fantasy and the Brain's Right Hemisphere.

    ERIC Educational Resources Information Center

    Shuman, R. Baird

    While the left hemisphere of the brain is responsible for logical and verbal activity, the right brain is the center of much of human feeling and emotion. Its vision is holistic rather than segmented or compartmentalized. Although schools today are geared almost exclusively to training the brain's left hemisphere, fantasy literature can provide…

  13. Hemispheric Dominance of Native American Indian Students.

    ERIC Educational Resources Information Center

    Stellern, John; And Others

    1986-01-01

    Examines language and spatial lateralization of 49 elementary American Indian students using a cognitive-manual dual task model and psychoeducational assessment techniques. All students were found to be left-hemisphere dominant for language and some were lateralized to the left hemisphere for spatial function. Contradicts evidence of right-brain…

  14. Robust Controller Design for Hemispherical Resonator Gyroscope

    DTIC Science & Technology

    2011-11-01

    f v Figure 1. Operating principle of HRG Robust Controller Design for Hemispherical Resonator Gyroscope Chul Hyun1), Byung ...Petersburg, Russia.: 26-34 4) Chul Hyun. 2011. Design of Robust Digital Controller for Hemispherical Resonator Gyroscopes, Ph.D. dissertation, Seoul

  15. The Cost of Action Miscues: Hemispheric Asymmetries

    ERIC Educational Resources Information Center

    Shenal, Brian V.; Hinze, Stephan; Heilman, Kenneth M.

    2012-01-01

    Adaptive behaviors require preparation and when necessary inhibition or alteration of actions. The right hemisphere has been posited to be dominant for preparatory motor activation. This experiment was designed to learn if there are hemispheric asymmetries in the control of altered plans of actions. Cues, both valid and invalid, which indicate the…

  16. [Agraphia, cortical anarthria and planning disorders as a result of a lesion of the right hemisphere in a right-handed patient].

    PubMed

    Demeurisse, G; Coekaerts, M J; Hublet, C

    1984-01-01

    A right-hemisphere premotor cerebral infarct in a right-handed man from a largely left-handed family caused cortical anarthria and constructional agraphia. The effect of programming difficulties on impaired oral and written expression was demonstrated by the clinical picture of pure agraphia, which could thus be attributed to a primary disorder of programming. Measurements of cerebral blood flow three months after the accident showed that language representation was ambilateral.

  17. Deficits in the ability to use proprioceptive feedback in children with hemiplegic cerebral palsy.

    PubMed

    Goble, Daniel J; Hurvitz, Edward A; Brown, Susan H

    2009-09-01

    Compared with motor impairment in children with hemiplegic cerebral palsy (CP), less attention has been paid to sensory feedback processing deficits. This includes, especially, proprioceptive information regarding arm position. This study examined the ability of children with hemiplegic CP to use proprioceptive feedback during a goal-directed target-matching task. Eight children with hemiplegic CP and eight typically developing children performed proprioceptively guided matching of elbow position with either arm. Between groups, it was found that matching errors were significantly greater for the affected arm of children with hemiplegic CP. With respect to the side of brain injury, deficits were only seen for children with right hemisphere damage. These results provide valuable information that may assist in the development of more effective sensorimotor rehabilitation and training paradigms.

  18. Cerebral Atrophy

    MedlinePlus

    ... two lobes of the brain that form the cerebrum) are affected, conscious thought and voluntary processes may ... two lobes of the brain that form the cerebrum) are affected, conscious thought and voluntary processes may ...

  19. Hemispheric lateralization of semantic feature distinctiveness.

    PubMed

    Reilly, M; Machado, N; Blumstein, S E

    2015-08-01

    Recent models of semantic memory propose that the semantic representation of concepts is based, in part, on a network of features. In this view, a feature that is distinctive for an object (a zebra has stripes) is processed differently from a feature that is shared across many objects (a zebra has four legs). The goal of this paper is to determine whether there are hemispheric differences in such processing. In a feature verification task, participants responded 'yes' or 'no' following concepts which were presented to a single visual field (left or right) paired with a shared or distinctive feature. Both hemispheres showed faster reaction times to shared features than to distinctive features, although right hemisphere responses were significantly slower overall and particularly in the processing of distinctive features. These findings support models of semantic processing in which the dominant left hemisphere more efficiently performs highly discriminating 'fine' encoding, in contrast to the right hemisphere which performs less discriminating 'coarse' encoding.

  20. UV Observations of Hemispheric Asymmetry

    NASA Astrophysics Data System (ADS)

    Schaefer, R. K.; Paxton, L. J.; Wolven, B. C.; Zhang, Y.; Romeo, G.

    2015-12-01

    Asymmetry in the auroral patterns can be an important diagnostic for understanding the dynamics of solar wind interaction with the magnetosphere-ionosphere-thermosphere system (e.g., Newel and Meng, 1998; Fillingrim et al., 2005). Molecular nitrogen emission in the UV Lyman-Birge-Hopfield bands can be used to determine energy flux and electron mean energy (Sotirelis, et al, 2013) and thereby Hall and Pederson integrated conductances (Gjerloev, et al., 2014). UV imagery provided by the 4 SSUSI instruments on the Defense Meteorological Satellite Program (DMSP) F16-F19 spacecraft provide two dimensional maps of this emission at different local times. Often there are near simultaneous observations of both poles by some combination of the satellites. (see figure 1) The SSUSI auroral data products are well suited to this study, as they have the following features.: - dayglow has been subtracted on dayside aurora - electron energy flux and mean energy are pre-calculated - individual arcs have been identified through image processing. In order to intercompare data from multiple satellites, we must first ensure that the instrument calibrations are consistent. In this work we show that the instruments are consistently calibrated, and that results generated from the SSUSI data products can be trusted. Several examples of storm time asymmetries captured by the SSUSI instruments will be discussed. Fillingim, M. O., G. K. Parks, H. U. Frey, T. J. Immel, and S. B. Mende (2005), Hemispheric asymmetry of the afternoon electron aurora, Geophys. Res. Lett., 32, L03113, doi:10.1029/2004GL021635. Gjerloev, J., Schaefer, R., Paxton, L, and Zhang, Y. (2014), A comprehensive empirical model of the ionospheric conductivity derived from SSUSI/GUVI, SuperMAG and SuperDARN data, SM51G-4339, Fall 2014 AGU meeting, San Francisco. Newell, P. T., and C.-I. Meng (1988), Hemispherical asymmetry in cusp precipitation near solstices, J. Geophys. Res., 93(A4), 2643-2648, doi:10.1029/JA093iA04p02643

  1. The orbicularis oculi response after hemispheral damage.

    PubMed Central

    Berardelli, A; Accornero, N; Cruccu, G; Fabiano, F; Guerrisi, V; Manfredi, M

    1983-01-01

    The corneal and blink reflexes were evaluated in 20 normal subjects and in 30 patients with motor deficits secondary to unilateral hemispheral lesions of vascular origin. In the normal population there were no differences between subjects below and subjects above 50 years of age. In the patients the reflex evoked by electrical stimulation of the cornea of the clinically affected side was depressed in 24 out of 30 cases. The depression mainly affected the afferent branch of the circuit, which triggers both homolateral and contralateral orbicularis oculi discharge (afferent abnormality). In three cases the depression was exerted concomitantly on the efferent branch (afferent and efferent abnormality) and only in one case was it limited to the efferent branch (efferent abnormality). The late R2 component of the blink reflex was depressed in 15 out of 30 patients. The early R1 component was slightly facilitated on the affected side. The changes of the corneal reflex and of the R2 component of blink reflex were similar, but the blink reflex had a greater safety factor. The patients with an abnormal corneal reflex had more extensive damage than had the patients with normal corneal response, as shown by computer tomography, but the site of the lesion was comparable in the two groups. Conduction through the brain stem circuits mediating the orbicularis oculi response is normally under pyramidal facilitatory influences while facial motoneurons are subjected to pyramidal inhibition. After pyramidal damage the transmission of impulses in the brain stem was slowed down, ultimately to a degree that abolished the reflex. Removal of pyramidal inhibition on facial motoneurons is probably the basis of the slight facilitation of the R1 component of the blink reflex. Images PMID:6311988

  2. HEMISPHERIC CENTER FOR ENVIRONMENTAL TECHNOLOGY

    SciTech Connect

    M.A. Ebadian

    1999-10-31

    The Deactivation and Decommissioning (D&D) Technology Assessment Program (TAP) was developed to provide detailed, comparable data for environmental technologies and to disseminate this data to D&D professionals in a manner that will facilitate the review and selection of technologies to perform decontamination and decommissioning. The objectives for this project include the following: Determine technology needs through review of the Site Technology Coordination Group (STCG) information and other applicable websites and needs databases; Perform a detailed review of industries that perform similar activities as those required in D&D operations to identify additional technologies; Define the technology assessment program for characterization and waste management problem sets; Define the data management program for characterization, dismantlement, and waste management problem sets; Evaluate baseline and innovative technologies under standard test conditions at Florida International University's Hemispheric Center for Environmental Technology (FIU-HCET) and other locations and collect data in the areas of performance, cost, health and safety, operations and maintenance, and primary and secondary waste generation; Continue to locate, verify, and incorporate technology performance data from other sources into the multimedia information system; and Develop the conceptual design for a dismantlement technology decision analysis tool for dismantlement technologies.

  3. Hemispheric sunspot unit area: comparison with hemispheric sunspot number and sunspot area

    SciTech Connect

    Li, K. J.; Xiang, N. B.; Qu, Z. N.; Xie, J. L.

    2014-03-01

    The monthly mean northern and southern hemispheric sunspot numbers (SNs) and sunspot areas (SAs) in the time interval of 1945 January to 2012 December are utilized to construct the monthly northern and southern hemispheric sunspot unit areas (SUAs), which are defined as the ratio of hemispheric SA to SN. Hemispheric SUAs are usually found to rise at the beginning and to fall at the ending time of a solar cycle more rapidly, forming a more irregular cycle profile than hemispheric SNs and SAs, although it also presents Schwabe-cycle-like hemispheric SNs and SAs. Sunspot activity (SN, SA, and SUA) is found asynchronously and is asymmetrically distributed in the northern and southern hemispheres, and hemispheric SNs, SAs, and SUAs are not in phase in the two hemispheres. The similarity of hemispheric SNs and SAs is found to be much more obvious than that of hemispheric SUAs and SNs (or SAs), and also for their north-south asymmetry. A notable feature is found for the behavior of the SUA around the minimum time of cycle 24: the SUA rapidly decreases from the cycle maximum value to the cycle minimum value of sunspot cycles 19-24 within just 22 months.

  4. Frequency and patterns of abnormality detected by iodine-123 amine emission CT after cerebral infarction

    SciTech Connect

    Brott, T.G.; Gelfand, M.J.; Williams, C.C.; Spilker, J.A.; Hertzberg, V.S.

    1986-03-01

    Single photon emission computed tomography (SPECT) was performed in 31 patients with cerebral infarction and 13 who had had transient ischemic attacks, using iodine-123-labeled N,N,N'-trimethyl-N'-(2-hydroxyl-3-methyl-5-iodobenzyl)-1,3-propanediamin e (I-123-HIPDM) as the radiopharmaceutical. SPECT scans were compared with computed tomographic (CT) scans. SPECT was as sensitive as CT in detecting cerebral infarction (94% vs. 84%). The abnormalities were larger on the SPECT scans than on the CT scans in 19 cases, equal in seven, and smaller in five (SPECT abnormalities greater than or equal to CT abnormalities in 86% of cases). Fifteen of 30 patients with hemispheric infarction had decreased perfusion (decreased uptake of I-123-HIPDM) to the cerebellar hemisphere contralateral to the cerebral hemisphere involved by the infarction (crossed cerebellar diaschisis). Nine of these 15 patients had major motor deficits, while only one of the 15 without crossed cerebellar diaschisis had a major motor deficit.

  5. Functional changes in inter- and intra-hemispheric cortical processing underlying degraded speech perception.

    PubMed

    Bidelman, Gavin M; Howell, Megan

    2016-01-01

    Previous studies suggest that at poorer signal-to-noise ratios (SNRs), auditory cortical event-related potentials are weakened, prolonged, and show a shift in the functional lateralization of cerebral processing from left to right hemisphere. Increased right hemisphere involvement during speech-in-noise (SIN) processing may reflect the recruitment of additional brain resources to aid speech recognition or alternatively, the progressive loss of involvement from left linguistic brain areas as speech becomes more impoverished (i.e., nonspeech-like). To better elucidate the brain basis of SIN perception, we recorded neuroelectric activity in normal hearing listeners to speech sounds presented at various SNRs. Behaviorally, listeners obtained superior SIN performance for speech presented to the right compared to the left ear (i.e., right ear advantage). Source analysis of neural data assessed the relative contribution of region-specific neural generators (linguistic and auditory brain areas) to SIN processing. We found that left inferior frontal brain areas (e.g., Broca's areas) partially disengage at poorer SNRs but responses do not right lateralize with increasing noise. In contrast, auditory sources showed more resilience to noise in left compared to right primary auditory cortex but also a progressive shift in dominance from left to right hemisphere at lower SNRs. Region- and ear-specific correlations revealed that listeners' right ear SIN advantage was predicted by source activity emitted from inferior frontal gyrus (but not primary auditory cortex). Our findings demonstrate changes in the functional asymmetry of cortical speech processing during adverse acoustic conditions and suggest that "cocktail party" listening skills depend on the quality of speech representations in the left cerebral hemisphere rather than compensatory recruitment of right hemisphere mechanisms.

  6. Disordered cholinergic neurotransmission and dysautoregulation after acute cerebral infarction.

    PubMed

    Ott, E O; Abraham, J; Meyer, J S; Achari, A N; Chee, A N; Mathew, N T

    1975-01-01

    The possible role of displaced neurotransmitter acetylcholine (ACHh) in dysautoregulation was examined after experimental regional cerebral infarction was produced by occluding the middle cerebral artery (MCA) in babons. Regional cerebral blood flow (rCBF) was measured after intracarotid injection of 133Xenon using the gamma camera. Autoregulation was tested with metaraminol or angiotensin infusion and the autoregulation index (A.I.) was calculated. Acetylcholinesterase (ACHhE) was measured in brain tissue of noninfarcted and infarcted hemispheres. Cerebral arteriovenous (A-V) differences for cholinesterase (ChE) were also measured. Regional dysautoregulation was found in infarcted gray matter and correlated with increased AChE levels in the same zones of cortex and basal ganglia. The time course of onset of dysautoregulation correlated with increased ChE uptake by the brain. Intravenous infusion of the cholinergic neurotransmitter blocker, scopolamine, restored autoregulation to the ischemic zones. Autoregulation appears to be a myogenic reflex, influenced by neurogenic and metabolic mechanisms.

  7. Evidence for topographic organization in the cerebellum of motor control versus cognitive and affective processing

    PubMed Central

    Stoodley, Catherine J.; Schmahmann, Jeremy D.

    2010-01-01

    Patients with cerebellar damage often present with the cerebellar motor syndrome of dysmetria, dysarthria and ataxia, yet cerebellar lesions can also result in the cerebellar cognitive affective syndrome, including executive, visual-spatial, and linguistic impairments, and affective dysregulation. We have hypothesized that there is topographic organization in the human cerebellum such that the anterior lobe and lobule VIII contain the representation of the sensorimotor cerebellum; lobules VI and VII of the posterior lobe comprise the cognitive cerebellum; and the posterior vermis is the anatomical substrate of the limbic cerebellum. Here we analyze anatomical, functional neuroimaging, and clinical data to test this hypothesis. We find converging lines of evidence supporting regional organization of motor, cognitive, and limbic behaviors in the cerebellum. The cerebellar motor syndrome results when lesions involve the anterior lobe and parts of lobule VI, interrupting cerebellar communication with cerebral and spinal motor systems. Cognitive impairments occur when posterior lobe lesions affect lobules VI and VII (including Crus I, Crus II, and lobule VIIB), disrupting cerebellar modulation of cognitive loops with cerebral association cortices. Neuropsychiatric disorders manifest when vermis lesions deprive cerebrocerebellar limbic loops of cerebellar input. We consider this functional topography to be a consequence of the differential arrangement of connections of the cerebellum with the spinal cord, brainstem, and cerebral hemispheres, reflecting cerebellar incorporation into the distributed neural circuits subserving movement, cognition, and emotion. These observations provide testable hypotheses for future investigations. PMID:20152963

  8. Changes in southern hemispheric polar amplification over the past 5 million years revealed by climate modelling

    NASA Astrophysics Data System (ADS)

    Hoencamp, Jori; Stap, Lennert; Tuenter, Erik; Lourens, Luc; van de Wal, Roderik

    2016-04-01

    Knowledge on polar amplification is important to relate high latitude climate records to global mean temperature changes. Several studies have pointed out that the strength of polar amplification in the Northern Hemisphere varies considerably due to the presence of large ice sheets and more sea ice during colder climate conditions. As a result, the polar amplification in the Northern Hemisphere decreases for warmer climates. In this study, we address the fact that these changes in the Northern Hemisphere also affect the polar amplification in the Southern Hemisphere. We study the Southern and Northern Hemisphere amplification together over the past 5 million years with the CLIMBER-2 intermediate complexity model. Radiation, land ice extent and height, and greenhouse gases are prescribed as forcing. We find that in contrast to the reduction in polar amplification in the Northern Hemisphere, polar amplification in the Southern Hemisphere increases for warmer climates. The amplification decreases in the Northern Hemisphere from 2.7 during glacial conditions to 1.6 for a pre-industrial climate, which is line with other climate simulations. Over the same CO2 range the southern hemispheric polar amplification increases from 1 to 1.6. This is caused by the fact that the atmospheric transport needed to balance the radiation surplus in the equatorial region needs to be compensated by relatively stronger transport of energy in Southern direction while the transport in Northern direction reduces. This reduction in Northern direction is driven by less (land and sea) ice resulting in a smaller meridional gradient in Northern direction and hence a smaller atmospheric transport. As a consequence, the traditional scaled (with LGM temperature) Dome C record needs to be corrected with a maximum of 0.6 degrees half-way glacial and interglacial conditions, if it is to be interpreted as global mean temperature change indicator. While this changes the amplitude, the phasing of

  9. Hemispheric Asymmetries in Substorm Recovery Time Scales

    NASA Technical Reports Server (NTRS)

    Fillingim, M. O.; Chua, D H.; Germany, G. A.; Spann, James F.

    2009-01-01

    Previous statistical observations have shown that the recovery time scales of substorms occurring in the winter and near equinox (when the nighttime auroral zone was in darkness) are roughly twice as long as the recovery time scales for substorms occurring in the summer (when the nighttime auroral region was sunlit). This suggests that auroral substorms in the northern and southern hemispheres develop asymmetrically during solstice conditions with substorms lasting longer in the winter (dark) hemisphere than in the summer (sunlit) hemisphere. Additionally, this implies that more energy is deposited by electron precipitation in the winter hemisphere than in the summer one during substorms. This result, coupled with previous observations that have shown that auroral activity is more common when the ionosphere is in darkness and is suppressed when the ionosphere is in daylight, strongly suggests that the ionospheric conductivity plays an important role governing how magnetospheric energy is transferred to the ionosphere during substorms. Therefore, the ionosphere itself may dictate how much energy it will accept from the magnetosphere during substorms rather than this being an externally imposed quantity. Here, we extend our earlier work by statistically analyzing the recovery time scales for a large number of substorms observed in the conjugate hemispheres simultaneously by two orbiting global auroral imagers: Polar UVI and IMAGE FUV. Our current results are consistent with previous observations. The recovery time scales are observed to be longer in the winter (dark) hemisphere while the auroral activity has a shorter duration in the summer (sunlit) hemisphere. This leads to an asymmetric energy input from the magnetosphere to the ionosphere with more energy being deposited in the winter hemisphere than in the summer hemisphere.

  10. Remote canopy hemispherical image collection system

    NASA Astrophysics Data System (ADS)

    Wan, Xuefen; Liu, Bingyu; Yang, Yi; Han, Fang; Cui, Jian

    2016-11-01

    Canopies are major part of plant photosynthesis and have distinct architectural elements such as tree crowns, whorls, branches, shoots, etc. By measuring canopy structural parameters, the solar radiation interception, photosynthesis effects and the spatio-temporal distribution of solar radiation under the canopy can be evaluated. Among canopy structure parameters, Leaf Area Index (LAI) is the key one. Leaf area index is a crucial variable in agronomic and environmental studies, because of its importance for estimating the amount of radiation intercepted by the canopy and the crop water requirements. The LAI can be achieved by hemispheric images which are obtained below the canopy with high accuracy and effectiveness. But existing hemispheric images canopy-LAI measurement technique is based on digital SLR camera with a fisheye lens. Users need to collect hemispheric image manually. The SLR camera with fisheye lens is not suit for long-term canopy-LAI outdoor measurement too. And the high cost of SLR limits its capacity. In recent years, with the development of embedded system and image processing technology, low cost remote canopy hemispheric image acquisition technology is becoming possible. In this paper, we present a remote hemispheric canopy image acquisition system with in-field/host configuration. In-field node based on imbed platform, low cost image sensor and fisheye lens is designed to achieve hemispherical image of plant canopy at distance with low cost. Solar radiation and temperature/humidity data, which are important for evaluating image data validation, are obtained for invalid hemispherical image elimination and node maintenance too. Host computer interacts with in-field node by 3G network. The hemispherical image calibration and super resolution are used to improve image quality in host computer. Results show that the remote canopy image collection system can make low cost remote canopy image acquisition for LAI effectively. It will be a potential

  11. Right hemisphere involvement in non-fluent primary progressive aphasia.

    PubMed

    Repetto, Claudia; Manenti, Rosa; Cotelli, Maria; Calabria, Marco; Zanetti, Orazio; Borroni, Barbara; Padovani, Alessandro; Miniussi, Carlo

    2007-01-01

    We described a 56-years-old man with a diagnosis of "non-fluent primary progressive aphasia" (NfPPA). An accurate neuropsychological, neurological and neuroimaging evaluation was performed in order to assess clinical and behavioural features of the patient. From a neuropsychological point of view, the patient showed a typical cognitive profile of subjects affected by NfPPA: a prominent language deficit, associated with impairments in several cognitive domains after three years from the onset of the symptomatology. The most intriguing feature is that SPECT revealed hypoperfusion in the right frontal cortex, albeit the patient is right-handed. This unexpected finding shows that NfPPA may arise not only from cortical abnormalities in the language-dominant left hemisphere, but also from right hemisphere involvement in a right hander (crossed aphasia).

  12. Compact Autonomous Hemispheric Vision System

    NASA Technical Reports Server (NTRS)

    Pingree, Paula J.; Cunningham, Thomas J.; Werne, Thomas A.; Eastwood, Michael L.; Walch, Marc J.; Staehle, Robert L.

    2012-01-01

    Solar System Exploration camera implementations to date have involved either single cameras with wide field-of-view (FOV) and consequently coarser spatial resolution, cameras on a movable mast, or single cameras necessitating rotation of the host vehicle to afford visibility outside a relatively narrow FOV. These cameras require detailed commanding from the ground or separate onboard computers to operate properly, and are incapable of making decisions based on image content that control pointing and downlink strategy. For color, a filter wheel having selectable positions was often added, which added moving parts, size, mass, power, and reduced reliability. A system was developed based on a general-purpose miniature visible-light camera using advanced CMOS (complementary metal oxide semiconductor) imager technology. The baseline camera has a 92 FOV and six cameras are arranged in an angled-up carousel fashion, with FOV overlaps such that the system has a 360 FOV (azimuth). A seventh camera, also with a FOV of 92 , is installed normal to the plane of the other 6 cameras giving the system a > 90 FOV in elevation and completing the hemispheric vision system. A central unit houses the common electronics box (CEB) controlling the system (power conversion, data processing, memory, and control software). Stereo is achieved by adding a second system on a baseline, and color is achieved by stacking two more systems (for a total of three, each system equipped with its own filter.) Two connectors on the bottom of the CEB provide a connection to a carrier (rover, spacecraft, balloon, etc.) for telemetry, commands, and power. This system has no moving parts. The system's onboard software (SW) supports autonomous operations such as pattern recognition and tracking.

  13. Pathogenic mutations associated with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy differently affect Jagged1 binding and Notch3 activity via the RBP/JK signaling Pathway.

    PubMed

    Joutel, Anne; Monet, Marie; Domenga, Valérie; Riant, Florence; Tournier-Lasserve, Elisabeth

    2004-02-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular dementia characterized by the degeneration of smooth-muscle cells in small cerebral arteries. CADASIL is caused by mutations in NOTCH3, one of the four mammalian homologs to the Drosophila melanogaster NOTCH gene. Disease-associated mutations are distributed throughout the 34 epidermal growth factor-like repeats (EGFRs) that compose the extracellular domain of the Notch3 receptor and result in a loss or a gain of a cysteine residue in one of these EGFRs. In human adults, Notch3 expression is highly restricted to vascular smooth-muscle cells. In patients with CADASIL, there is an abnormal accumulation of Notch3 in the vessel. Molecular pathways linking NOTCH3 mutations to degeneration of vascular smooth-muscle cells are as yet poorly understood. In this study, we investigated the effect of CADASIL mutations on Notch3 activity. We studied five naturally occurring mutations: R90C and C212S, located in the previously identified mutational hotspot EGFR2-5; C428S, shown in this study to be located in the ligand-binding domain EGFR10-11; and C542Y and R1006C, located in EGFR13 and EGFR26, respectively. All five mutant proteins were correctly processed. The C428S and C542Y mutant receptors exhibited a significant reduction in Jagged1-induced transcriptional activity of a RBP/JK responsive luciferase reporter, relative to wild-type Notch3. Impaired signaling activity of these two mutants arose through different mechanisms; the C428S mutant lost its Jagged1-binding ability, whereas C542Y retained it but exhibited an impaired presentation to the cell surface. In contrast, the R90C, C212S, and R1006C mutants retained the ability to bind Jagged1 and were associated with apparently normal levels of signaling activity. We conclude that mutations in Notch3 differently affect Jagged1 binding and Notch3 signaling via the RBP/JK pathway.

  14. The callosal dilemma: explaining diaschisis in the context of hemispheric rivalry via a neural network model.

    PubMed

    Reggia, J A; Goodall, S M; Shkuro, Y; Glezer, M

    2001-07-01

    It is often suggested that a major factor in diaschisis is the loss of transcallosal excitation to the intact hemisphere from the lesioned one. However, there is long-standing disagreement in the broader experimental literature about whether transcallosal interhemispheric influences in the human brain are primarily excitatory or inhibitory. Some experimental data are apparently better explained by assuming inhibitory callosal influences. Past neural network models attempting to explore this issue have encountered the same dilemma: in intact models, inhibitory callosal influences best explain strong cerebral lateralization like that occurring with language, but in lesioned models, excitatory callosal influences best explain experimentally observed hemispheric activation patterns following brain damage. We have now developed a single neural network model that can account for both types of data, i.e., both diaschisis and strong hemisphere specialization in the normal brain, by combining excitatory callosal influences with subcortical cross-midline inhibitory interactions. The results suggest that subcortical competitive processes may be a more important factor in cerebral specialization than is generally recognized.

  15. Magnetic resonance imaging of cerebral anomalies in subjects with resistance to thyroid hormone

    SciTech Connect

    Leonard, C.M.; Hauser, P.; Weintraub, B.D. |

    1995-06-19

    Resistance to thyroid hormone (RTH) is an autosomal dominant disease caused by mutations in the human thyroid receptor beta gene on chromosome 3. Individuals with RTH have an increased incidence of attention deficit hyperactivity disorder (ADHD). The purpose of this study was to search for developmental brain malformations associated with RTH. Forty-three subjects (20 affected males [AM], 23 affected females [AF]) with resistance to thyroid hormone and 32 unaffected first degree relatives (18 unaffected males [UM], 14 unaffected females [UF]) underwent MRI brain scans with a volumetric acquisition that provided 90 contiguous 2 mm thick sagittal images. Films of six contiguous images beginning at a standard sagittal position lateral to the insula were analyzed by an investigator who was blind with respect to subject characteristics. The presence of extra or missing gyri in the parietal bank of the Sylvian fissure (multimodal association cortex) and multiple Heschl`s transverse gyri (primary auditory cortex) were noted. There was a significantly increased frequency of anomalous Sylvian fissures in the left hemisphere in males with RTH (AM: 70%; AF: 30%; UM: 28% UF: 28%). Also, there was an increased frequency of anomalous Sylvian fissures on the left combined with multiple Heschl`s gyri in either hemisphere in males with RTH (AM: 50%; AF: 9%; UM: 6%; UF: 0%). However, RTH subjects with anomalies did not have an increased frequency of ADHD as compared with RTH subjects with no anomalies. Abnormal thyroid hormone action in the male fetus early during brain development may be associated with grossly observable cerebral anomalies of the left hemisphere. The effects of mutations in the thyroid receptor beta gene provide a model system for studying the complex interaction of genetic and non-genetic factors on brain and behavioral development. 19 refs., 2 figs., 2 tabs.

  16. Regional cerebral blood flow in schizophrenia

    SciTech Connect

    Mathew, R.J.; Duncan, G.C.; Weinman, M.L.; Barr, D.L.

    1982-10-01

    Regional cerebral blood flow (rCBF) was measured via xenon133 inhalation technique in 23 patients with schizophrenia and 18 age- and sex-matched controls. The mean blood flow to both hemispheres was found to be lower for the patients. The patients and their controls did not differ on interhemispheric differences in blood flow. There were no differences in rCBF between medicated and unmedicated, subchronic and chronic, and paranoid and nonparanoid patients. Hallucinations were associated with reduced blood flow to several postcentral regions.

  17. The Effects of Spatial Smoothing on Solar Magnetic Helicity Parameters and the Hemispheric Helicity Sign Rule

    NASA Astrophysics Data System (ADS)

    Koch Ocker, Stella; Petrie, Gordon

    2016-12-01

    The hemispheric preference for negative/positive helicity to occur in the northern/southern solar hemisphere provides clues to the causes of twisted, flaring magnetic fields. Previous studies on the hemisphere rule may have been affected by seeing from atmospheric turbulence. Using Hinode/SOT-SP data spanning 2006-2013, we studied the effects of two spatial smoothing tests that imitate atmospheric seeing: noise reduction by ignoring pixel values weaker than the estimated noise threshold, and Gaussian spatial smoothing. We studied in detail the effects of atmospheric seeing on the helicity distributions across various field strengths for active regions (ARs) NOAA 11158 and NOAA 11243, in addition to studying the average helicities of 179 ARs with and without smoothing. We found that, rather than changing trends in the helicity distributions, spatial smoothing modified existing trends by reducing random noise and by regressing outliers toward the mean, or removing them altogether. Furthermore, the average helicity parameter values of the 179 ARs did not conform to the hemisphere rule: independent of smoothing, the weak-vertical-field values tended to be negative in both hemispheres, and the strong-vertical-field values tended to be positive, especially in the south. We conclude that spatial smoothing does not significantly affect the overall statistics for space-based data, and thus seeing from atmospheric turbulence seems not to have significantly affected previous studies’ ground-based results on the hemisphere rule.

  18. Intraoperative cerebral blood flow imaging of rodents

    NASA Astrophysics Data System (ADS)

    Li, Hangdao; Li, Yao; Yuan, Lu; Wu, Caihong; Lu, Hongyang; Tong, Shanbao

    2014-09-01

    Intraoperative monitoring of cerebral blood flow (CBF) is of interest to neuroscience researchers, which offers the assessment of hemodynamic responses throughout the process of neurosurgery and provides an early biomarker for surgical guidance. However, intraoperative CBF imaging has been challenging due to animal's motion and position change during the surgery. In this paper, we presented a design of an operation bench integrated with laser speckle contrast imager which enables monitoring of the CBF intraoperatively. With a specially designed stereotaxic frame and imager, we were able to monitor the CBF changes in both hemispheres during the rodent surgery. The rotatable design of the operation plate and implementation of online image registration allow the technician to move the animal without disturbing the CBF imaging during surgery. The performance of the system was tested by middle cerebral artery occlusion model of rats.

  19. Complementary acupuncture treatment increases cerebral metabolism in patients with Parkinson's disease.

    PubMed

    Huang, Yong; Jiang, Xuemei; Zhuo, Ying; Tang, Anwu; Wik, Gustav

    2009-01-01

    We used positron emission tomography (PET) and the 18-flourodeoxyglucose tracer to study cerebral effects of complementary acupuncture in Parkinson's disease. Five patients received scalp-acupuncture and Madopa, while the other five had Madopa only. PET scans before and after 5 weeks of complementary acupuncture treatment show increased glucose metabolisms in parietal, temporal, occipital lobes, the thalamus, and the cerebellum in the light-diseased hemisphere, and in parietal and occipital lobes of the severe-diseased hemisphere. No changes were observed in the Madopa-only group. Acupuncture in combination with Madopa may improve cerebral glucose metabolism in Parkinson's disease.

  20. Cerebral blood flow changes during sodium-lactate-induced panic attacks

    SciTech Connect

    Stewart, R.S.; Devous, M.D. Sr.; Rush, A.J.; Lane, L.; Bonte, F.J.

    1988-04-01

    Dynamic single-photon emission computed axial tomography (CAT) with inhaled xenon-133 was used to measure regional cerebral blood flow in 10 drug-free patients with DSM-III-diagnosed panic disorder and in five normal control subjects. All subjects underwent regional cerebral blood flow studies while at rest or during normal saline infusion and during sodium lactate infusion. Six of the 10 patients and none of the control subjects experienced lactate-induced panic attacks. Lactate infusion markedly raised hemispheric blood flow levels in both control subjects and patients who did not panic. Patients who did panic experienced either a minimal increase or a decrease in hemispheric blood flow.

  1. Non-invasive near-infrared fluorescence imaging of the neutrophil response in a mouse model of transient cerebral ischaemia.

    PubMed

    Vaas, Markus; Enzmann, Gaby; Perinat, Therese; Siler, Ulrich; Reichenbach, Janine; Licha, Kai; Kipar, Anja; Rudin, Markus; Engelhardt, Britta; Klohs, Jan

    2016-10-27

    Near-infrared fluorescence (NIRF) imaging enables non-invasive monitoring of molecular and cellular processes in live animals. Here we demonstrate the suitability of NIRF imaging to investigate the neutrophil response in the brain after transient middle cerebral artery occlusion (tMCAO). We established procedures for ex vivo fluorescent labelling of neutrophils without affecting their activation status. Adoptive transfer of labelled neutrophils in C57BL/6 mice before surgery resulted in higher fluorescence intensities over the ischaemic hemisphere in tMCAO mice with NIRF imaging when compared with controls, corroborated by ex vivo detection of labelled neutrophils using fluorescence microscopy. NIRF imaging showed that neutrophils started to accumulate immediately after tMCAO, peaking at 18 h, and were still visible until 48 h after reperfusion. Our data revealed accumulation of neutrophils also in extracranial tissue, indicating damage in the external carotid artery territory in the tMCAO model. Antibody-mediated inhibition of α4-integrins did reduce fluorescence signals at 18 and 24, but not at 48 h after reperfusion, compared with control treatment animals. Antibody treatment reduced cerebral lesion volumes by 19%. In conclusion, the non-invasive nature of NIRF imaging allows studying the dynamics of neutrophil recruitment and its modulation by targeted interventions in the mouse brain after transient experimental cerebral ischaemia.

  2. Cerebral Lateralization is Protective in the Very Prematurely Born.

    PubMed

    Scheinost, Dustin; Lacadie, Cheryl; Vohr, Betty R; Schneider, Karen C; Papademetris, Xenophon; Constable, R Todd; Ment, Laura R

    2015-07-01

    Individuals born prematurely are at risk for developmental delay, and converging data suggest alterations in neural networks in the developing preterm brain. Nevertheless, those critical period processes such as cerebral lateralization that underlie these findings remain largely unexplored. To test the hypothesis that preterm birth alters the fundamental program of corticogenesis in the developing brain, we interrogated cerebral lateralization at rest in very prematurely born participants and term controls at young adulthood. Employing a novel, voxel-based measure of functional connectivity, these data demonstrate for the first time that cerebral lateralization of functional connectivity in right hemisphere language homologs is altered for very preterm participants. Very preterm participants with no evidence for severe brain injury exhibited a significant decrease in right hemisphere lateralization in the right parietal and temporal lobes in this data driven analysis. Further, for the very preterm participants, but not the term participants, these fundamental alterations in the cerebral lateralization for language significantly correlate with language scores. These findings provide evidence that cerebral asymmetry is both plastic and experiential, and suggest the need for further study of underlying environmental factors responsible for these changes.

  3. Huge Filament Rises From Sun's Northern Hemisphere

    NASA Video Gallery

    On August 1, 2010 following a C3-class solar flare from sunspot 1092, an enormous magnetic filament stretching across the sun's northern hemisphere erupted. This 304 angstrom video shows that filam...

  4. The effect of musical experience on hemispheric lateralization in musical feature processing.

    PubMed

    Ono, Kentaro; Nakamura, Akinori; Yoshiyama, Kenji; Kinkori, Takeshi; Bundo, Masahiko; Kato, Takashi; Ito, Kengo

    2011-06-01

    Music consists of a variety of spectral and temporal features. Generally, brain processing of these features is reported as being right hemisphere dominant. However, there are contradicting results as to whether musical experience affects hemispheric laterality or not. In the present study, we investigated the effect of musical experience on hemispheric lateralization of musical feature processing using magnetoencephalography (MEG). Mismatch fields (MMFs) were measured from 8 musicians and 8 nonmusicians in oddball tasks with four different musical features, including pitch, chord, timbre and rhythm. Regardless of the features, the MMFs showed right-hemispheric dominance in nonmusicians, whereas musicians showed symmetrical MMF amplitudes in both hemispheres. The electrical activity around the auditory cortex to the MMFs also supported the right-hemispheric dominance in nonmusicians and bilateral activation in musicians. Voxel-based morphometry did not detect any group differences around the auditory cortices. These results suggest that musical training changes the hemispheric roles for musical feature processing in the pre-attentive stage, and this functional alteration can occur without apparent anatomical changes.

  5. Neuroimaging in cerebrovascular disorders: measurement of cerebral physiology after stroke and assessment of stroke recovery.

    PubMed

    Mountz, James M; Liu, Hong-Gang; Deutsch, Georg

    2003-01-01

    , magnetic resonance imaging, and magnetic resonance spectroscopy. Data show how standard structural magnetic resonance imaging, (99m)Tc hexamethylpropylene amine oxime SPECT, PET imaging, and magnetic resonance spectroscopy can be used to identify the extent of permanent damage versus penumbral and remote effects of a stroke. The results of the analysis of the pure-diaschisis model show a high correlation between the rCBF brain SPECT defect volume in the cortex and the magnetic resonance spectroscopic imaging (MRSI) change in the white matter. There is a statistically significant positive correlation between the 2 (P <.01; r(2) = 0.94). The increased creatine/N-acetyl aspartate and reduced rCBF are proposed to be due to an increase in the white matter creatine component due to diaschisis and the repair mechanisms associated with increased astrocytosis, in addition to a reduction of N-acetyl aspartate in diaschitic white matter. Xenon-133 dynamic SPECT is shown to be a quantitative and sensitive measure of cerebrovascular status and hemodynamic constraints in both spared and affected brain, providing evidence for reorganization and cerebral plasticity. Fluorine-18 PET and (31)P spectroscopic imaging data show reorganizational changes in the contralesional hemisphere after stroke. The phosphocreatine-adenosine triphosphate ratio in the contralesional hemisphere was 38% +/- 17% higher than in the ipsilateral hemisphere. The phosphocreatine-adenosine triphosphate ratio was highly correlated (r = 0.88, P <.05) with increasing (18)F-fluorodeoxyglucose uptake. These results showed that there is a parallel change in glucose metabolism and high-energy phosphate metabolism associated with poststroke recovery that is proposed to be due to cerebral reorganization in the contralateral premotor cortex. The value of these results on rehabilitation strategy, including possible criteria for the use of facilitatory versus compensatory approaches, is analyzed.

  6. Southern Hemisphere Polygonal Patterned Ground

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On Earth, periglacial is a term that refers to regions and processes where cold climate contributes to the evolution of landforms and landscapes. Common in periglacial environments on Earth, such as the arctic of northern Canada,Siberia, and Alaska, is a phenomenon called patterned ground. The 'patterns' in patterned ground often take the form of large polygons, each bounded by either troughs or ridges made up of rock particles different in size from those seen in the interior of the polygon. On Earth, many polygons in periglacial environments are directly linked to water: they typically form from stresses induced by repeated freezing and thawing of water, contraction from stress induced by changing temperatures, and sorting of rocks brought to the surface along polygon boundaries by the freeze-thaw processes. Although not exclusively formed by freezing and thawing of water, that is often the dominant mechanism on Earth.

    Polygons similar to those found in Earth's arctic and antarctic regions are also found in the polar regions of Mars. Typically, they occur on crater floors, or on intercrater plains, between about 60o and 80o latitude. The polygons are best seen when bright frost or dark sand has been trapped in the troughs that form the polygon boundaries. Three examples of martian polygons seen by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) are shown here. Each is located in the southern hemisphere:(left) Polygon troughs highlighted by frost as the south polar cap retreats during spring. The circular features are the locations of buried craters that were originally formed by meteor impact. This image, E09-00029, is located at 75.1oS, 331.3oW, and was acquired on 1 October 2001.(center) Summertime view of polygons, highlighted by dark, windblown sand, on the floor of a crater at 71.2oS, 282.6oW. The image, E12-02319, was obtained on 21January 2002.(right) Polygon troughs highlighted by the retreating south polar frost cap during southern summer

  7. Cerebral sinus venous thrombosis

    PubMed Central

    Alvis-Miranda, Hernando Raphael; Milena Castellar-Leones, Sandra; Alcala-Cerra, Gabriel; Rafael Moscote-Salazar, Luis

    2013-01-01

    Cerebral sinus venous thrombosis (CSVT) is a rare phenomenon that can be seen with some frequency in young patients. CSVT is a multifactorial condition with gender-related specific causes, with a wide clinical presentation, the leading causes differ between developed and developing countries, converting CSVT in a condition characterized by a highly variable clinical spectra, difficult diagnosis, variable etiologies and prognosis that requires fine medical skills and a high suspicious index. Patients who presents with CSVT should underwent to CT-scan venography (CVT) and to the proper inquiry of the generating cause. This disease can affect the cerebral venous drainage and related anatomical structure. The symptoms may appear in relation to increased intracranial pressure imitating a pseudotumorcerebri. Prognosis depends on the early detection. Correcting the cause, generally the complications can be prevented. Mortality trends have diminished, and with the new technologies, surely it will continue. This work aims to review current knowledge about CSVT including its pathogenesis, etiology, clinical manifestations, diagnosis, and treatment. PMID:24347950

  8. Cerebral Palsy (For Kids)

    MedlinePlus

    ... de los dientes Video: Getting an X-ray Cerebral Palsy KidsHealth > For Kids > Cerebral Palsy Print A A ... the things that kids do every day. What's CP? Some kids with CP use wheelchairs and others ...

  9. Cerebral Palsy (For Kids)

    MedlinePlus

    ... Emergency Room? What Happens in the Operating Room? Cerebral Palsy KidsHealth > For Kids > Cerebral Palsy A A A ... the things that kids do every day. What's CP? Some kids with CP use wheelchairs and others ...

  10. Hemispherical map for the human brain cortex

    NASA Astrophysics Data System (ADS)

    Tosun, Duygu; Prince, Jerry L.

    2001-07-01

    Understanding the function of the human brain cortex is a primary goal in human brain mapping. Methods to unfold and flatten the cortical surface for visualization and measurement have been described in previous literature; but comparison across multiple subjects is still difficult because of the lack of a standard mapping technique. We describe a new approach that maps each hemisphere of the cortex to a portion of a sphere in a standard way, making comparison of anatomy and function across different subjects possible. Starting with a three-dimensional magnetic resonance image of the brain, the cortex is segmented and represented as a triangle mesh. Defining a cut around the corpus collosum identifies the left and right hemispheres. Together, the two hemispheres are mapped to the complex plane using a conformal mapping technique. A Mobius transformation, which is conformal, is used to transform the points on the complex plane so that a projective transformation maps each brain hemisphere onto a spherical segment comprising a sphere with a cap removed. We determined the best size of the spherical cap by minimizing the relative area distortion between hemispherical maps and original cortical surfaces. The relative area distortion between the hemispherical maps and the original cortical surfaces for fifteen human brains is analyzed.

  11. Differential hemispheric modulation of preparatory attention.

    PubMed

    Fernández, Laura Gabriela; Siéroff, Eric

    2014-06-01

    Preparatory attention (PA) is the ability to allocate attention to a stimulus prior to its occurrence and is a crucial component of attentional control. We investigated the role of brain hemispheres in PA using an experimental test in which normal participants responded to a target that could appear in the right or the left visual fields, thus projecting to the left or the right hemispheres, while ignoring a central distractor that could appear in the preparatory phase preceding the target. This experimental test measures the ability of participants to modulate PA directed to a target location when the probability of a distractor occurrence varies across three blocks of trials (0%, 33%, 67%). The competition between distractors and target for PA should produce slower response times when the probability of distractors is high. Three experiments were conducted varying the temporal predictability of the target occurrence within a trial (high predictability in Experiments 1 and 3, and low predictability in Experiment 2), and the task used (location in Experiments 1 and 2, and detection in Experiment 3). We found that the modulation of PA by the expected probability of events was different in each visual field/hemisphere. Whereas the left hemisphere PA was influenced by the mere probability of events in each block of trials, the right hemisphere PA was mainly influenced by events with high temporal predictability. These results suggest that each hemisphere uses a different strategy to modulate PA when directed to a target location at the perceptual level of visual processing.

  12. Northern Hemisphere forcing of Southern Hemisphere climate during the last deglaciation.

    PubMed

    He, Feng; Shakun, Jeremy D; Clark, Peter U; Carlson, Anders E; Liu, Zhengyu; Otto-Bliesner, Bette L; Kutzbach, John E

    2013-02-07

    According to the Milankovitch theory, changes in summer insolation in the high-latitude Northern Hemisphere caused glacial cycles through their impact on ice-sheet mass balance. Statistical analyses of long climate records supported this theory, but they also posed a substantial challenge by showing that changes in Southern Hemisphere climate were in phase with or led those in the north. Although an orbitally forced Northern Hemisphere signal may have been transmitted to the Southern Hemisphere, insolation forcing can also directly influence local Southern Hemisphere climate, potentially intensified by sea-ice feedback, suggesting that the hemispheres may have responded independently to different aspects of orbital forcing. Signal processing of climate records cannot distinguish between these conditions, however, because the proposed insolation forcings share essentially identical variability. Here we use transient simulations with a coupled atmosphere-ocean general circulation model to identify the impacts of forcing from changes in orbits, atmospheric CO(2) concentration, ice sheets and the Atlantic meridional overturning circulation (AMOC) on hemispheric temperatures during the first half of the last deglaciation (22-14.3 kyr BP). Although based on a single model, our transient simulation with only orbital changes supports the Milankovitch theory in showing that the last deglaciation was initiated by rising insolation during spring and summer in the mid-latitude to high-latitude Northern Hemisphere and by terrestrial snow-albedo feedback. The simulation with all forcings best reproduces the timing and magnitude of surface temperature evolution in the Southern Hemisphere in deglacial proxy records. AMOC changes associated with an orbitally induced retreat of Northern Hemisphere ice sheets is the most plausible explanation for the early Southern Hemisphere deglacial warming and its lead over Northern Hemisphere temperature; the ensuing rise in atmospheric CO(2

  13. Aging and Cerebral Palsy.

    ERIC Educational Resources Information Center

    Networker, 1993

    1993-01-01

    This special edition of "The Networker" contains several articles focusing on aging and cerebral palsy (CP). "Aging and Cerebral Palsy: Pathways to Successful Aging" (Jenny C. Overeynder) reports on the National Invitational Colloquium on Aging and Cerebral Palsy held in April 1993. "Observations from an Observer" (Kathleen K. Barrett) describes…

  14. Upright or inverted, entire or exploded: right-hemispheric superiority in face recognition withstands multiple spatial manipulations.

    PubMed

    Prete, Giulia; Marzoli, Daniele; Tommasi, Luca

    2015-01-01

    Background. The ability to identify faces has been interpreted as a cerebral specialization based on the evolutionary importance of these social stimuli, and a number of studies have shown that this function is mainly lateralized in the right hemisphere. The aim of this study was to assess the right-hemispheric specialization in face recognition in unfamiliar circumstances. Methods. Using a divided visual field paradigm, we investigated hemispheric asymmetries in the matching of two subsequent faces, using two types of transformation hindering identity recognition, namely upside-down rotation and spatial "explosion" (female and male faces were fractured into parts so that their mutual spatial relations were left intact), as well as their combination. Results. We confirmed the right-hemispheric superiority in face processing. Moreover, we found a decrease of the identity recognition for more extreme "levels of explosion" and for faces presented upside-down (either as sample or target stimuli) than for faces presented upright, as well as an advantage in the matching of female compared to male faces. Discussion. We conclude that the right-hemispheric superiority for face processing is not an epiphenomenon of our expertise, because we are not often exposed to inverted and "exploded" faces, but rather a robust hemispheric lateralization. We speculate that these results could be attributable to the prevalence of right-handedness in humans and/or to early biases in social interactions.

  15. Atypical category processing and hemispheric asymmetries in high-functioning children with autism: revealed through high-density EEG mapping.

    PubMed

    Fiebelkorn, Ian C; Foxe, John J; McCourt, Mark E; Dumas, Kristina N; Molholm, Sophie

    2013-05-01

    Behavioral evidence for an impaired ability to group objects based on similar physical or semantic properties in autism spectrum disorders (ASD) has been mixed. Here, we recorded brain activity from high-functioning children with ASD as they completed a visual-target detection task. We then assessed the extent to which object-based selective attention automatically generalized from targets to non-target exemplars from the same well-known object class (e.g., dogs). Our results provide clear electrophysiological evidence that children with ASD (N=17, aged 8-13 years) process the similarity between targets (e.g., a specific dog) and same-category non-targets (SCNT) (e.g., another dog) to a lesser extent than do their typically developing (TD) peers (N=21). A closer examination of the data revealed striking hemispheric asymmetries that were specific to the ASD group. These findings align with mounting evidence in the autism literature of anatomic underconnectivity between the cerebral hemispheres. Years of research in individuals with TD have demonstrated that the left hemisphere (LH) is specialized toward processing local (or featural) stimulus properties and the right hemisphere (RH) toward processing global (or configural) stimulus properties. We therefore propose a model where a lack of communication between the hemispheres in ASD, combined with typical hemispheric specialization, is a root cause for impaired categorization and the oft-observed bias to process local over global stimulus properties.

  16. Emotion and pain: a functional cerebral systems integration.

    PubMed

    Mollet, Gina A; Harrison, David W

    2006-09-01

    Emotion and pain are psychological constructs that have received extensive attention in neuropsychological research. However, neuropsychological models of emotional processing have made more progress in describing how brain regions interact to process emotion. Theories of emotional processing can describe inter-hemispheric and intra-hemispheric interactions during emotional processing. Due to similarities between emotion and pain, it is thought that emotional models can be applied to pain. The following review examines the neuropsychology of emotion and pain using a functional cerebral systems approach. Specific comparisons are made between pain and anger. Attention is given to differences in cerebral function and physiology that may contribute to the processing of emotion and pain. Suggestions for future research in emotion and pain are given.

  17. Visual speech perception in foveal and extrafoveal vision: further implications for divisions in hemispheric projections.

    PubMed

    Jordan, Timothy R; Sheen, Mercedes; Abedipour, Lily; Paterson, Kevin B

    2014-01-01

    When observing a talking face, it has often been argued that visual speech to the left and right of fixation may produce differences in performance due to divided projections to the two cerebral hemispheres. However, while it seems likely that such a division in hemispheric projections exists for areas away from fixation, the nature and existence of a functional division in visual speech perception at the foveal midline remains to be determined. We investigated this issue by presenting visual speech in matched hemiface displays to the left and right of a central fixation point, either exactly abutting the foveal midline or else located away from the midline in extrafoveal vision. The location of displays relative to the foveal midline was controlled precisely using an automated, gaze-contingent eye-tracking procedure. Visual speech perception showed a clear right hemifield advantage when presented in extrafoveal locations but no hemifield advantage (left or right) when presented abutting the foveal midline. Thus, while visual speech observed in extrafoveal vision appears to benefit from unilateral projections to left-hemisphere processes, no evidence was obtained to indicate that a functional division exists when visual speech is observed around the point of fixation. Implications of these findings for understanding visual speech perception and the nature of functional divisions in hemispheric projection are discussed.

  18. Right-hemisphere reading in a case of developmental deep dyslexia.

    PubMed

    Pitchford, Nicola J; Funnell, Elaine; De Haan, Bianca; Morgan, Paul S

    2007-09-01

    The right-hemisphere hypothesis of deep dyslexia has received support from functional imaging studies of acquired deep dyslexia following damage to the left cerebral hemisphere, but no imaging studies of cases of developmental deep dyslexia, in which brain damage is not suspected, have been reported. In this paper, we report the first evidence of right hyperactivation in an adult case of developmental deep dyslexia. Hyperactivation was observed in the right inferior frontal cortex during functional magnetic resonance imaging (fMRI) of the oral reading of imageable content words and nonwords to which imageable lexical responses were frequently made. No evidence of right hyperactivation was observed in the oral reading of function words, nor during the naming of imageable words in response to pictured objects. The results reveal strategic and selective use of right-hemisphere functions for particular types of written stimuli. We propose that children with developmental deep dyslexia compensate for their lack of phonological skills by accessing right-hemisphere imageable associations that provide a mnemonic for linking written forms to spoken names.

  19. Visual Speech Perception in Foveal and Extrafoveal Vision: Further Implications for Divisions in Hemispheric Projections

    PubMed Central

    Jordan, Timothy R.; Sheen, Mercedes; Abedipour, Lily; Paterson, Kevin B.

    2014-01-01

    When observing a talking face, it has often been argued that visual speech to the left and right of fixation may produce differences in performance due to divided projections to the two cerebral hemispheres. However, while it seems likely that such a division in hemispheric projections exists for areas away from fixation, the nature and existence of a functional division in visual speech perception at the foveal midline remains to be determined. We investigated this issue by presenting visual speech in matched hemiface displays to the left and right of a central fixation point, either exactly abutting the foveal midline or else located away from the midline in extrafoveal vision. The location of displays relative to the foveal midline was controlled precisely using an automated, gaze-contingent eye-tracking procedure. Visual speech perception showed a clear right hemifield advantage when presented in extrafoveal locations but no hemifield advantage (left or right) when presented abutting the foveal midline. Thus, while visual speech observed in extrafoveal vision appears to benefit from unilateral projections to left-hemisphere processes, no evidence was obtained to indicate that a functional division exists when visual speech is observed around the point of fixation. Implications of these findings for understanding visual speech perception and the nature of functional divisions in hemispheric projection are discussed. PMID:25032950

  20. The cerebral balance of power: confrontation or cooperation?

    PubMed

    Sergent, J

    1982-04-01

    Two visual search experiments were carried out using as stimuli large letters made of small identical letters presented in right, or left, or central visual fields. Considering the spatial frequency contents of the stimuli as the critical variable, Experiment 1 showed that a left-field superiority could be obtained whenever a decision had to be made on a large (low frequency) letter alone, and a right-field advantage emerged when a small (high frequency) letter had to be processed. Experiment 2 showed that the two levels of structure of the stimulus were not encoded at the same rate and that at very brief exposure, only the large letter could be accurately identified. This was accompanied by a left-field superiority, whether or not the stimulus contained the target. These results are interpreted as revealing a differential sensitivity of the hemispheres to the spatial frequency contents of a visual image, the right hemisphere being more adept at processing early-available low frequencies and the left hemisphere operating more efficiently on later-available low frequencies. From these and other experiments reviewed, it is suggested that (a) cerebral lateralization of cognitive functions results from differences in sensorimotor resolution capacities of the hemispheres; (b) both hemispheres can process verbal and visuospatial information, analytically and holistically; (c) respective hemispheric competence is a function of the level of sensorimotor resolution required for processing the information available.

  1. Clinical Focus on Prosodic, Discursive and Pragmatic Treatment for Right Hemisphere Damaged Adults: What's Right?

    PubMed Central

    Ferré, Perrine; Ska, Bernadette; Lajoie, Camille; Bleau, Amélie; Joanette, Yves

    2011-01-01

    Researchers and clinicians acknowledge today that the contribution of both cerebral hemispheres is necessary to a full and adequate verbal communication. Indeed, it is estimated that at least 50% of right brain damaged individuals display impairments of prosodic, discourse, pragmatics and/or lexical semantics dimensions of communication. Since the 1990's, researchers have focused on the description and the assessment of these impairments and it is only recently that authors have shown interest in planning specific intervention approaches. However, therapists in rehabilitation settings still have very few available tools. This review of recent literature demonstrates that, even though theoretical knowledge needs further methodological investigation, intervention guidelines can be identified to target right hemisphere damage communication impairments in clinical practice. These principles can be incorporated by speech and language pathologists, in a structured intervention framework, aiming at fully addressing prosodic, discursive and pragmatic components of communication. PMID:22110970

  2. What’s “right” in language comprehension: ERPs reveal right hemisphere language capabilities

    PubMed Central

    Federmeier, Kara D.; Wlotko, Edward W.; Meyer, Aaron M.

    2009-01-01

    Although the term “nonverbal” is often applied to the right cerebral hemisphere (RH), a growing body of work indicates that the RH can comprehend language and, indeed, that it makes critical contributions to normal language functions. Reviewed here are studies that have examined RH language capabilities by combining visual half-field presentation methods with event-related potential (ERP) measures. Because they afford temporal and functional specificity and can be obtained as participants simply process language for meaning, ERPs provide especially valuable insights into RH language functions. Such studies suggest that the RH appreciates word and message-level meaning information, and that it may play a particularly important role in the processing of relatively unpredictable semantic relationships. In addition, this work suggests that patterns observed for everyday language processing may often be an emergent property of multiple, distinct mechanisms operating in parallel as the left and right hemispheres jointly comprehend language. PMID:19777128

  3. Is math lateralised on the same side as language? Right hemisphere aphasia and mathematical abilities.

    PubMed

    Semenza, Carlo; Delazer, Margarete; Bertella, Laura; Granà, Alessia; Mori, Ileana; Conti, Fabio M; Pignatti, Riccardo; Bartha, Lisa; Domahs, Frank; Benke, Thomas; Mauro, Alessandro

    2006-10-09

    The main purpose of the present study was to learn how mathematical abilities are located and develop in the brain with respect to language. Mathematical abilities were assessed in six right-handed patients affected by aphasia following a lesion to their non-dominant hemisphere (crossed aphasia) and in two left-handed aphasics with a right-sided lesion. Acalculia, although in different degrees, was found in all cases. The type of acalculia depended on the type of aphasia, following patterns that have been previously observed in the most common aphasias resulting from left hemisphere lesions. No sign of right hemisphere or spatial acalculia (acalculia in left lateralised right-handed subjects) was detected. These results suggest that, as a rule, language and calculation share the same hemisphere. A primitive computational mechanism capable of recursion may be the precursor of both functions.

  4. Writing and drawing with both hands as indicators of hemispheric dominance.

    PubMed

    Labak, Irena; Snajder, Darija; Srzentić, Mirna Kostović; Bensić, Mirta; Nist, Marina; Ilakovac, Vesna; Heffer, Marija

    2011-01-01

    Brain lateralization is a common term used to describe dominance of one brain hemisphere over another for a specific function. The right hand dominance in writing, controlled by the left hemisphere, is preceded by development of communicative gesticulation and followed by development of speech in the same hemisphere. We assumed that some people are not aware of their own capability of using the other hand for tasks involving fine motor sequential movements. To prove this hypothesis, the participants were asked to perform one trained task (writing) and one less-trained task (drawing) with a dominant and a non-dominant hand. The final sample was comprised of 1189 children from 14 elementary schools and 8 high schools in the Osijek area, of which 685 elementary school children were attending 1st to 4th grade and 504 high school children were attending 3rd and 4th grade. The participants were asked to write two words, draw a specific object (a vase with flowers) and fill out a questionnaire with 10 questions concerning the classification of handedness and cerebral hemisphere dominance. The self-reported cerebral lateralization assessed in the questionnaire was compared with the drawing and the writing performance. The self-reported and objectively measured hand dominance deviated in the cases of the ambidextrous who consider themselves right-handers. Given the fact that the number of ambidextrous persons was greater in elementary schools than in high schools, we concluded how training of the right hand decreases the ability of using both hands equally for either of the tested functions - writing and drawing.

  5. Music Appreciation and Hemisphere Orientation: Visual versus Verbal Involvement.

    ERIC Educational Resources Information Center

    Zalanowski, Annette H.

    1990-01-01

    Analyzes effect of brain hemisphere orientation on music appreciation. Reports results from 36 left-hemisphere and 36 right-hemisphere undergraduates who responded to a musical selection verbally or visually. Finds right-hemisphere students show greater appreciation, measured by attention, understanding, and enjoyment scores. Discusses…

  6. Hemispheric Specialization and Cognitive Development: Implications for Mathematics Education

    ERIC Educational Resources Information Center

    Wheatley, Grayson, H.; And Others

    1978-01-01

    Evidence is presented for the theory that the two brain hemispheres process stimuli differently: the left hemisphere is specialized for logico-analytic tasks and the right hemisphere for visuo-spatial tasks. They contend that cognitive ability is related to the development of hemispheric asymmetry and present implications for mathematics education…

  7. Cerebral chemical dominance and neural regulation of cell division, cell proliferation, neoplastic transformation, and genomic function.

    PubMed

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-05-01

    The study assessed the isoprenoid pathway, digoxin synthesis, and neurotransmitter patterns in individuals of differing hemispheric dominance, neurogenetic disorders, and neoplasms. The HMG CoA reductase activity, serum digoxin, magnesium, tryptophan catabolites, tyrosine catabolites, and RBC membrane Na+-K+ ATPase activity were measured in individuals of differing hemispheric dominance. The digoxin status, membrane Na+-K+ ATPase activity, and serum magnesium were assessed in Huntington's disease, trisomy 21, glioblastoma multiforme, and non-Hodgkin's lymphoma (high grade lymphoma). The results showed that right hemispheric, chemically dominant individuals had elevated digoxin synthesis, increased tryptophan catabolites, and reduced tyrosine catabolites, and membrane Na+-K+ ATPase with hypomagnesemia. Left hemispheric, chemically dominant individuals had the opposite patterns. In neurogenetic disorders and neo plasms also hyperdigoxinemia induced membrane Na+-K+ ATPase inhibition, and hypomagnesemia similar to right hemispheric chemical dominance could be demonstrated. The role of hemispheric chemical dominance and hypothalamic digoxin secretion play a key role in the regulation of cell differentiation/proliferation and genomic function. Ninety-five percent of the patients with neurogenetic disorders and neoplasms were right-handed/left hemispheric dominant by dichotic listening test. However, all of them had biochemical patterns similar to right hemispheric chemical dominance. Hemispheric chemical dominance has no correlation to cerebral dominance detected by handness/dichotic listening test.

  8. Hemispheric asymmetries in cortical and subcortical anatomy.

    PubMed

    Kang, Xiaojian; Herron, Timothy J; Ettlinger, Marc; Woods, David L

    2015-01-01

    Previous research studies have reported many hemispherical asymmetries in cortical and subcortical anatomy, but only a subset of findings is consistent across studies. Here, we used improved Freesurfer-based automated methods to analyse the properties of the cortex and seven subcortical structures in 138 young adult subjects. Male and female subjects showed similar hemispheric asymmetries in gyral and sulcal structures, with many areas associated with language processing enlarged in the left hemisphere (LH) and a number of areas associated with visuospatial processing enlarged in the right hemisphere (RH). In addition, we found greater (non-directional) cortical asymmetries in subjects with larger brains. Asymmetries in subcortical structures included larger LH volumes of thalamus, putamen and globus pallidus and larger RH volumes of the cerebellum and the amygdala. We also found significant correlations between the subcortical structural volumes, particularly of the thalamus and cerebellum, with cortical area. These results help to resolve some of the inconsistencies in previous studies of hemispheric asymmetries in brain anatomy.

  9. Hemispheric lateralization of semantic feature distinctiveness

    PubMed Central

    Reilly, M.; Machado, N.; Blumstein, S. E.

    2015-01-01

    Recent models of semantic memory propose that the semantic representation of concepts is based, in part, on a network of features. In this view, a feature that is distinctive for an object (a zebra has stripes) is processed differently from a feature that is shared across many objects (a zebra has four legs). The goal of this paper is to determine whether there are hemispheric differences in such processing. In a feature verification task, participants responded ‘yes’ or ‘no’ following concepts which were presented to a single visual field (left or right) paired with a shared or distinctive feature. Both hemispheres showed faster reaction times to shared features than to distinctive features, although right hemisphere responses were significantly slower overall and particularly in the processing of distinctive features. These findings support models of semantic processing in which the dominant left hemisphere more efficiently performs highly discriminating ‘fine’ encoding, in contrast to the right hemisphere which performs less discriminating ‘coarse’ encoding. PMID:26022059

  10. Contrasting pediatric and adult cerebral malaria

    PubMed Central

    Hawkes, Michael; Elphinstone, Robyn E; Conroy, Andrea L; Kain, Kevin C

    2013-01-01

    Malaria affects millions of people around the world and a small subset of those infected develop cerebral malaria. The clinical presentation of cerebral malaria differs between children and adults, and it has been suggested that age-related changes in the endothelial response may account for some of these differences. During cerebral malaria, parasites sequester within the brain microvasculature but do not penetrate into the brain parenchyma and yet, the infection causes severe neurological symptoms. Endothelial dysfunction is thought to play an important role in mediating these adverse clinical outcomes. During infection, the endothelium becomes activated and more permeable, which leads to increased inflammation, hemorrhages, and edema in the surrounding tissue. We hypothesize that post-natal developmental changes, occurring in both endothelial response and the neurovascular unit, account for the differences observed in the clinical presentations of cerebral malaria in children compared with adults. PMID:23924893

  11. Dynamic contribution to hemispheric mean temperature trends

    SciTech Connect

    Wallace, J.M.; Zhang, Y.; Renwick, J.A.

    1995-11-03

    On the basis of land station data from the Northern Hemisphere, it was determined that roughly half of the temporal variance of monthly mean hemispheric mean anomalies in surface air temperature during the period from 1900 through 1990 were linearly related to the amplitude of a distinctive spatial pattern in which the oceans are anomalously cold and the continents are anomalously warm poleward of 40 degrees north when the hemisphere is warm. Apart from an upward trend since 1975, to which El Nino has contributed, the amplitude time series associated with this pattern resembles seasonally dependent white noise. it is argued that the variability associated with this pattern is dynamically induced and is not necessarily an integral part of the fingerprint of global warming. 12 refs., 5 figs., 1 tab.

  12. Single Mode Lasing from Hybrid Hemispherical Microresonators

    PubMed Central

    Chen, Rui; Van Duong Ta; Sun, Han Dong

    2012-01-01

    Enormous attention has been paid to optical microresonators which hold a great promise for microlasers as well as fundamental studies in cavity quantum electrodynamics. Here we demonstrate a three-dimensional (3D) hybrid microresonator combining self-assembled hemispherical structure with a planar reflector. By incorporating dye molecules into the hemisphere, optically pumped lasing phenomenon is observed at room temperature. We have studied the lasing behaviors with different cavity sizes, and particularly single longitudinal mode lasing from hemispheres with diameter ∼15 μm is achieved. Detailed characterizations indicate that the lasing modes shift under varying pump densities, which can be well-explained by frequency shift and mode hopping. This work provides a versatile approach for 3D confined microresonators and opens an opportunity to realize tunable single mode microlasers. PMID:22540027

  13. Regional cerebral blood flow during comprehension and speech (in cerebrally healthy subjects)

    SciTech Connect

    Lechevalier, B.; Petit, M.C.; Eustache, F.; Lambert, J.; Chapon, F.; Viader, F. )

    1989-07-01

    Regional cerebral blood flow (rCBF) was measured by the xenon-133 inhalation method in 10 cerebrally healthy subjects at rest and during linguistic activation tests. These consisted of a comprehension test (binaural listening to a narrative text) and a speech test (making sentences from a list of words presented orally at 30-s intervals). The comprehension task induced a moderate increase in the mean right CBF and in both inferior parietal areas, whereas the speech test resulted in a diffuse increase in the mean CBF of both hemispheres, predominating regionally in both inferior parietal, left operculary, and right upper motor and premotor areas. It is proposed that the activation pattern induced by linguistic stimulation depends on not only specific factors, such as syntactic and semantic aspects of language, but also the contents of the material proposed and the attention required by the test situation.

  14. Resting State and Diffusion Neuroimaging Predictors of Clinical Improvements Following Constraint-Induced Movement Therapy in Children With Hemiplegic Cerebral Palsy.

    PubMed

    Manning, Kathryn Y; Fehlings, Darcy; Mesterman, Ronit; Gorter, Jan Willem; Switzer, Lauren; Campbell, Craig; Menon, Ravi S

    2015-10-01

    The aim was to identify neuroimaging predictors of clinical improvements following constraint-induced movement therapy. Resting state functional magnetic resonance and diffusion tensor imaging data was acquired in 7 children with hemiplegic cerebral palsy. Clinical and magnetic resonance imaging (MRI) data were acquired at baseline and 1 month later following a 3-week constraint therapy regimen. A more negative baseline laterality index characterizing an atypical unilateral sensorimotor resting state network significantly correlated with an improvement in the Canadian Occupational Performance Measure score (r = -0.81, P = .03). A more unilateral network with decreased activity in the affected hemisphere was associated with greater improvements in clinical scores. Higher mean diffusivity in the posterior limb of the internal capsule of the affect tract correlated significantly with improvements in the Jebsen-Taylor score (r = -0.83, P = .02). Children with more compromised networks and tracts improved the most following constraint therapy.

  15. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke.

    PubMed

    Xing, Shihui; Lacey, Elizabeth H; Skipper-Kallal, Laura M; Jiang, Xiong; Harris-Love, Michelle L; Zeng, Jinsheng; Turkeltaub, Peter E

    2016-01-01

    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor's lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion-symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  16. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke.

    PubMed

    Xing, Shihui; Lacey, Elizabeth H; Skipper-Kallal, Laura M; Jiang, Xiong; Harris-Love, Michelle L; Zeng, Jinsheng; Turkeltaub, Peter E

    2015-10-31

    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor's lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion-symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  17. Kienböck's disease in cerebral palsy.

    PubMed

    Leclercq, C; Xarchas, C

    1998-12-01

    The incidence of Kienböck's disease is known to be higher in cerebral palsy patients, but little has been written on treatment. We report a case of Kienböck's disease in a young man affected by cerebral palsy. A proximal row carpectomy was done, which relieved spasticity at the same time as treating the disease.

  18. Cerebral blood flow asymmetries in headache-free migraineurs

    SciTech Connect

    Levine, S.R.; Welch, K.M.; Ewing, J.R.; Joseph, R.; D'Andrea, G.

    1987-11-01

    Regional cerebral blood flow (rCBF) asymmetries were studied in controls and patients with common and classic/complicated migraine using /sup 133/Xe inhalation with 8 homologously situated external collimators over each cerebral hemisphere. Migraine patients as a group more frequently had posterior rCBF asymmetries than controls (p less than 0.03). Although there were no differences in the number of anterior rCBF asymmetries, migraine patients had 2 or more asymmetric probe pairs more often than controls (p less than 0.02). The posterior rCBF asymmetries, consistent with the site of activation of many migraine attacks, may be related to more labile control of the cerebral circulation.

  19. Cerebral asymmetry and language development: cause, correlate or consequence?

    PubMed Central

    Bishop, Dorothy V. M.

    2014-01-01

    In most people language is processed predominantly by the left hemisphere, but we don’t know how or why. A popular view is that developmental language disorders result from a poorly lateralized brain, but until recently evidence has been weak and indirect. Modern neuroimaging methods have made it possible to study normal and abnormal development of lateralized function in the developing brain and have confirmed links with language and literacy impairments. However, there is little evidence that weak cerebral lateralization has common genetic origins with language/literacy impairments. Our understanding of the association between atypical language lateralization and developmental disorders may benefit if we reconceptualise the nature of cerebral asymmetry to recognize its multidimensional nature and to take into account variation in lateralization over developmental time. Contrary to popular belief, cerebral lateralization may not be a highly heritable, stable characteristic of individuals; rather, weak lateralization may be a consequence of impaired language learning. PMID:23766329

  20. Cerebral asymmetry and language development: cause, correlate, or consequence?

    PubMed

    Bishop, Dorothy V M

    2013-06-14

    In most people, language is processed predominantly by the left hemisphere of the brain, but we do not know how or why. A popular view is that developmental language disorders result from a poorly lateralized brain, but until recently, evidence has been weak and indirect. Modern neuroimaging methods have made it possible to study normal and abnormal development of lateralized function in the developing brain and have confirmed links with language and literacy impairments. However, there is little evidence that weak cerebral lateralization has common genetic origins with language and literacy impairments. Our understanding of the association between atypical language lateralization and developmental disorders may benefit if we reconceptualize the nature of cerebral asymmetry to recognize its multidimensionality and consider variation in lateralization over developmental time. Contrary to popular belief, cerebral lateralization may not be a highly heritable, stable characteristic of individuals; rather, weak lateralization may be a consequence of impaired language learning.

  1. A prognostic classification of cerebral cysticercosis: therapeutic implications.

    PubMed Central

    Estañol, B; Corona, T; Abad, P

    1986-01-01

    Cerebral cysticercosis is a parasitic infestation with a highly variable prognosis and diverse clinical manifestations. Over the period of two years 51 patients were studied prospectively with this infestation, paying particular attention to the duration and severity of the illness, clinical course, CT findings and therapeutic modalities. Patients with parenchymal cysts or calcification without hydrocephalus had a benign disorder presenting commonly with seizures. This type of infestation usually is long-standing, almost never requires surgical treatment, responds to praziquantel therapy and has a good prognosis. In contrast, patients who present with hydrocephalus, large supratentorial cysts, multiple granulomata with cerebral oedema or with vasculitis and cerebral infarction, have an aggressive, acute or subacute illness, presenting with raised intracranial pressure, gait disturbances, mental changes, seizures, cranial nerve palsies, hemisphere syndromes, chronic meningitis and stroke. This malignant form usually requires surgical therapy, does not respond to praziquantel and may produce a fatal outcome or serious sequelae. PMID:3783174

  2. Cerebral Dominance: Its Use in Understanding Learning Styles and Behavioral Patterns.

    ERIC Educational Resources Information Center

    Matthews, Doris B.

    Studies of the human brain suggest that cerebral dominance, the preference for either the right or the left hemisphere to direct the body's behavior, plays a causal role in distinctive learning styles and behavior patterns. The two halves of the brain are physically almost identical at birth, but childhood experiences which utilize one hemisphere…

  3. Sex Similarities in Verbal and Performance IQ Deficits Following Unilateral Cerebral Lesions.

    ERIC Educational Resources Information Center

    Herring, Sheldon; Reitan, Ralph M.

    1986-01-01

    Investigated whether men and women produced similar Verbal Intelligence Quotient (IQ) and Performance IQ patterns following unilateral cerebral lesions. No consistent evidence of Sex X Lesioned Hemisphere interactions was found. Differences in the lateralization effects between men and women were not reflected in direction or pattern but only in…

  4. Dynamic cerebral autoregulation and beat to beat blood pressure control are impaired in acute ischaemic stroke

    PubMed Central

    Eames, P; Blake, M; Dawson, S; Panerai, R; Potter, J

    2002-01-01

    Objectives: Hypertension and chronic cerebrovascular disease are known to alter static cerebral autoregulation (CA) but the effects of acute stroke on dynamic CA (dCA) have not been studied in detail. Those studies to date measuring dCA have used sympathetically induced blood pressure (BP) changes, which may themselves directly affect dCA. This study assessed whether dCA is compromised after acute stroke using spontaneous blood pressure (BP) changes as the stimulus for the dCA response. Methods: 56 patients with ischaemic stroke (aged 70 (SD 9) years), studied within 72 hours of ictus were compared with 56 age, sex, and BP matched normal controls. Cerebral blood flow velocity was measured using transcranial Doppler ultrasound (TCD) with non-invasive beat to beat arterial BP levels, surface ECG, and transcutaneous CO2 levels and a dynamic autoregulatory index (dARI) calculated. Results: Beat to beat BP, but not pulse interval variability was significantly increased and cardiac baroreceptor sensitivity (BRS) decreased in the patients with stroke. Dynamic CA was significantly reduced in patients with stroke compared with controls (strokes: ARI 3.8 (SD 2.2) and 3.2 (SD 2.0) for pressor and depressor stimuli respectively v controls: ARI 4.7 (SD 2.2) and 4.5 (SD 2.0) respectively (p<0.05 in all cases)). There was no difference between stroke and non-stroke hemispheres in ARI, which was also independent of severity of stroke, BP, BP variability, BRS, sex, and age. Conclusion: Dynamic cerebral autoregulation, as assessed using spontaneous transient pressor and depressor BP stimuli, is globally impaired after acute ischaemic stroke and may prove to be an important factor in predicting outcome. PMID:11909905

  5. Does Preoperative Measurement of Cerebral Blood Flow with Acetazolamide Challenge in Addition to Preoperative Measurement of Cerebral Blood Flow at the Resting State Increase the Predictive Accuracy of Development of Cerebral Hyperperfusion after Carotid Endarterectomy? Results from 500 Cases with Brain Perfusion Single-photon Emission Computed Tomography Study

    PubMed Central

    OSHIDA, Sotaro; OGASAWARA, Kuniaki; SAURA, Hiroaki; YOSHIDA, Koji; FUJIWARA, Shunro; KOJIMA, Daigo; KOBAYASHI, Masakazu; YOSHIDA, Kenji; KUBO, Yoshitaka; OGAWA, Akira

    2015-01-01

    The purpose of the present study was to determine whether preoperative measurement of cerebral blood flow (CBF) with acetazolamide in addition to preoperative measurement of CBF at the resting state increases the predictive accuracy of development of cerebral hyperperfusion after carotid endarterectomy (CEA). CBF at the resting state and cerebrovascular reactivity (CVR) to acetazolamide were quantitatively assessed using N-isopropyl-p-[123I]-iodoamphetamine (IMP)-autoradiography method with single-photon emission computed tomography (SPECT) before CEA in 500 patients with ipsilateral internal carotid artery stenosis (≥ 70%). CBF measurement using 123I-IMP SPECT was also performed immediately and 3 days after CEA. A region of interest (ROI) was automatically placed in the middle cerebral artery territory in the affected cerebral hemisphere using a three-dimensional stereotactic ROI template. Preoperative decreases in CBF at the resting state [95% confidence intervals (CIs), 0.855 to 0.967; P = 0.0023] and preoperative decreases in CVR to acetazolamide (95% CIs, 0.844 to 0.912; P < 0.0001) were significant independent predictors of post-CEA hyperperfusion. The area under the receiver operating characteristic curve for prediction of the development of post-CEA hyperperfusion was significantly greater for CVR to acetazolamide than for CBF at the resting state (difference between areas, 0.173; P < 0.0001). Sensitivity, specificity, and positive- and negative-predictive values for the prediction of the development of post-CEA hyperperfusion were significantly greater for CVR to acetazolamide than for CBF at the resting state (P < 0.05, respectively). The present study demonstrated that preoperative measurement of CBF with acetazolamide in addition to preoperative measurement of CBF at the resting state increases the predictive accuracy of the development of post-CEA hyperperfusion. PMID:25746308

  6. Does preoperative measurement of cerebral blood flow with acetazolamide challenge in addition to preoperative measurement of cerebral blood flow at the resting state increase the predictive accuracy of development of cerebral hyperperfusion after carotid endarterectomy? Results from 500 cases with brain perfusion single-photon emission computed tomography study.

    PubMed

    Oshida, Sotaro; Ogasawara, Kuniaki; Saura, Hiroaki; Yoshida, Koji; Fujiwara, Shunro; Kojima, Daigo; Kobayashi, Masakazu; Yoshida, Kenji; Kubo, Yoshitaka; Ogawa, Akira

    2015-01-01

    The purpose of the present study was to determine whether preoperative measurement of cerebral blood flow (CBF) with acetazolamide in addition to preoperative measurement of CBF at the resting state increases the predictive accuracy of development of cerebral hyperperfusion after carotid endarterectomy (CEA). CBF at the resting state and cerebrovascular reactivity (CVR) to acetazolamide were quantitatively assessed using N-isopropyl-p-[(123)I]-iodoamphetamine (IMP)-autoradiography method with single-photon emission computed tomography (SPECT) before CEA in 500 patients with ipsilateral internal carotid artery stenosis (≥ 70%). CBF measurement using (123)I-IMP SPECT was also performed immediately and 3 days after CEA. A region of interest (ROI) was automatically placed in the middle cerebral artery territory in the affected cerebral hemisphere using a three-dimensional stereotactic ROI template. Preoperative decreases in CBF at the resting state [95% confidence intervals (CIs), 0.855 to 0.967; P = 0.0023] and preoperative decreases in CVR to acetazolamide (95% CIs, 0.844 to 0.912; P < 0.0001) were significant independent predictors of post-CEA hyperperfusion. The area under the receiver operating characteristic curve for prediction of the development of post-CEA hyperperfusion was significantly greater for CVR to acetazolamide than for CBF at the resting state (difference between areas, 0.173; P < 0.0001). Sensitivity, specificity, and positive- and negative-predictive values for the prediction of the development of post-CEA hyperperfusion were significantly greater for CVR to acetazolamide than for CBF at the resting state (P < 0.05, respectively). The present study demonstrated that preoperative measurement of CBF with acetazolamide in addition to preoperative measurement of CBF at the resting state increases the predictive accuracy of the development of post-CEA hyperperfusion.

  7. Affective Aprosodia from a Medial Frontal Stroke

    ERIC Educational Resources Information Center

    Heilman, Kenneth M.; Leon, Susan A.; Rosenbek, John C.

    2004-01-01

    Background and objectives: Whereas injury to the left hemisphere induces aphasia, injury to the right hemisphere's perisylvian region induces an impairment of emotional speech prosody (affective aprosodia). Left-sided medial frontal lesions are associated with reduced verbal fluency with relatively intact comprehension and repetition…

  8. Hemispheric Differences in Processing Handwritten Cursive

    ERIC Educational Resources Information Center

    Hellige, Joseph B.; Adamson, Maheen M.

    2007-01-01

    Hemispheric asymmetry was examined for native English speakers identifying consonant-vowel-consonant (CVC) non-words presented in standard printed form, in standard handwritten cursive form or in handwritten cursive with the letters separated by small gaps. For all three conditions, fewer errors occurred when stimuli were presented to the right…

  9. Right Hemisphere Specialization for Color Detection

    ERIC Educational Resources Information Center

    Sasaki, Hitoshi; Morimoto, Akiko; Nishio, Akira; Matsuura, Sumie

    2007-01-01

    Three experiments were carried out to investigate hemispheric asymmetry in color processing among normal participants. In Experiment 1, it was shown that the reaction times (RTs) of the dominant and non-dominant hands assessed using a visual target presented at the central visual field, were not significantly different. In Experiment 2, RTs of…

  10. Hemispherical asymmetry in cusp precipitation near solstices

    SciTech Connect

    Newell, P.T.; Meng, C.

    1988-04-01

    A statistical comparison of the peak flux in electron and ion polar cusp precipitation in the summer and winter hemispheres as observed by the low-altitude DMSP F7 satellite is performed. Data studied encompass four consecutive solstices from December 1983 to June 1985, comprising 77 days of data with a total of 292 individual cusp passes. On each day, observations were restricted to those few hours UT in which the interhemispherical MLT variation of DMSP F7 was smallest. After the remaining local time effect was averaged out, the summer hemisphere ion (electron) precipitating energy flux was larger, on the average, by 61 +- 11% (51 +- 5%) than that in the winter hemisphere. However, the average particle energy was always lower for both species in the summer hemisphere. These effects generally hold true for northward as well as southward interplanetary magnetic fields (IMF). It is argued that the observed asymmetry is very hard to explain if the most intense part of the cusp lies on closed field lines, but it is shown that the standard open field line model of the cusp virtually requires the observed differences to occur. The present results thus suggest that the most intense portion of the cusp lies on open field lines even for northward IMF. copyright American Geophysical Union 1988

  11. Right-hemisphere specialization for contour grouping.

    PubMed

    Volberg, Gregor

    2014-01-01

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

  12. Hemispheric Learning and the Hispanic Student.

    ERIC Educational Resources Information Center

    Contreras, Maximiliano

    People of different cultures differ in the cognitive style they use. Research reports that Mexican American children indicate a preference for field-sensitive cognitive strategies that are spatial-holistic, and middle class children a preference for field-independent strategies that are verbal-analytic. Brain research in hemisphericity appears to…

  13. An Evaluative Review of Hemispheric Learning Potential

    DTIC Science & Technology

    1985-10-01

    patients with left-sided damage on certain items of the Seashore test of musical abilities...1978) Problem-solving strategies and manifest brain asymmetry. Cortex, 14, 474-484. Wechsler, A.F. (1973) The effect of organic brain disease on ...mologous locales In the two hemispheres. The effects of unilateral brain dam- age were thus interpreted as disorders consequent on

  14. Creative Cognitive Processes and Hemispheric Specialization.

    ERIC Educational Resources Information Center

    Poreh, A. M.; Whitman, R. D.

    1991-01-01

    The relationship between creative thought processes and hemispheric asymmetry was examined in 47 right-handed male undergraduates. Four factors were identified, accounting for 75 percent of the total variance: Verbal Divergent Thinking Factor, Nonverbal Divergent Thinking Factor, Convergent Verbal Search Factor, and Cognitive Complexity Factor.…

  15. Rethinking a Right Hemisphere Deficit in ADHD

    ERIC Educational Resources Information Center

    Hale, T. Sigi; Loo, Sandra K.; Zaidel, Eran; Hanada, Grant; Macion, James; Smalley, Susan L.

    2009-01-01

    Introduction: Early observations from lesion studies suggested right hemisphere (RH) dysfunction in ADHD. However, a strictly right-lateralized deficit has not been well supported. An alternatively view suggests increased R greater than L asymmetry of brain function and abnormal interhemispheric interaction. If true, RH pathology in ADHD should…

  16. Focal cerebral mantle disruption in fetal hydrocephalus.

    PubMed

    Humphreys, Peter; Muzumdar, Dattatraya P; Sly, Lloyd E; Michaud, Jean

    2007-04-01

    A variety of developmental brain anomalies have been described in individuals with fetal hydrocephalus, regardless of etiology. Examples include callosal dysgenesis, periventricular gray matter heterotopia, hippocampal and white matter hypoplasia, and cortical polygyration. The present report draws attention to another anomaly not reported in previous case series of fetal hydrocephalus: focal cerebral mantle disruption. Neonatal imaging findings (where available) and post-shunt, stable-state magnetic resonance imaging, or pathological findings were reviewed in 77 subjects with fetal hydrocephalus (55 myelomeningocele, 16 sporadic aqueductal stenosis, 6 miscellaneous). Of these, 12 subjects (15.6%) demonstrated a combination of absence of the septum pellucidum and severe thinning or absence of the posteromesial cerebral mantle. On axial sequences, this combination created the illusion of a common ventricle, as in lobar holoprosencephaly. All 12 subjects had massive hydrocephalus at birth, accompanied in 7 by posteromesial ventricular diverticula. Two subjects, and one other subject with distinct lateral ventricles, demonstrated unilateral or bilateral mantle clefts suggestive of schizencephaly. Close radiological (n = 2) or pathological (n = 1) inspection showed that the clefts were only partially lined with gray matter and contained a transverse gliotic membrane. These findings are consistent with the hypothesis that massive early fetal hydrocephalus may completely disrupt cerebral mantle formation, particularly in the posteromesial hemispheres.

  17. The use of erythtropoietin in cerebral diseases.

    PubMed

    Cotena, S; Piazza, O; Tufano, R

    2008-06-01

    Global and focal cerebral ischemia is followed by a secondary damage characterized by oxidative stress, excitotoxicity, inflammation and apoptosis. Erythropoietin (EPO) exerts antiapoptotic, anti-inflammatory, antioxidative, angiogenetic and neurotrophic properties. Its potential therapeutic role has been demonstrated in several animal models of cerebral ischemia and also in a clinical trial of ischemic stroke, so it could be considered an ideal compound for neuroprotection in ischemic stroke and in cardiac arrest. Intracerebral hemorrhage (ICH) is the least treatable form of stroke; the mechanisms involved in the secondary brain injury include hematoma mass effect, neuronal apoptosis and necrosis, inflammation. It has been demonstrated in an experimental ICH that EPO intervenes in the inflammatory process, reduces brain water content, hemorrhage volume and hemispheric atrophy, promotes cell survival, preserves cerebral blood flow, has antiapoptotic protective function against oxidative stress and excitotoxic damage. EPO can attenuate acute vasoconstriction and prevent brain ischemic damage in subarachnoid hemorrhage. The neuroprotective function of EPO has been studied also in traumatic brain injury: it reduces the inflammation and improves cognitive and motor deficits. The authors review some of the physiological actions of EPO in the physiopathology of ischemic and hemorrhagic stroke, subarachnoid hemorrhage and brain trauma, and its potential usefulness in the brain injured patient management.

  18. Statins and cerebral hemodynamics

    PubMed Central

    Giannopoulos, Sotirios; Katsanos, Aristeidis H; Tsivgoulis, Georgios; Marshall, Randolph S

    2012-01-01

    HMG-CoA reductase inhibitors (statins) are associated with improved stroke outcome. This observation has been attributed in part to the palliative effect of statins on cerebral hemodynamics and cerebral autoregulation (CA), which are mediated mainly through the upregulation of endothelium nitric oxide synthase (eNOS). Several animal studies indicate that statin pretreatment enhances cerebral blood flow after ischemic stroke, although this finding is not further supported in clinical settings. Cerebral vasomotor reactivity, however, is significantly improved after long-term statin administration in most patients with severe small vessel disease, aneurysmal subarachnoid hemorrhage, or impaired baseline CA. PMID:22929438

  19. Tone-language speakers show hemispheric specialization and differential cortical processing of contour and interval cues for pitch.

    PubMed

    Bidelman, G M; Chung, W-L

    2015-10-01

    Electrophysiological studies demonstrate that the neural coding of pitch is modulated by language experience and the linguistic relevance of the auditory input; both rightward and leftward asymmetries have been observed in the hemispheric specialization for pitch. In music, pitch is encoded using two primary features: contour (patterns of rises and falls) and interval (frequency separation between tones) cues. Recent evoked potential studies demonstrate that these "global" (contour) and "local" (interval) aspects of pitch are processed automatically (but bilaterally) in trained musicians. Here, we examined whether alternate forms of pitch expertise, namely, tone-language experience (i.e., Chinese), influence the early detection of contour and intervallic deviations within ongoing pitch sequences. Neuroelectric mismatch negativity (MMN) potentials were recorded in Chinese speakers and English-speaking nonmusicians in response to continuous pitch sequences with occasional global or local deviations in the ongoing melodic stream. This paradigm allowed us to explore potential cross-language differences in the hemispheric weighting for contour and interval processing of pitch. Chinese speakers showed differential pitch encoding between hemispheres not observed in English listeners; Chinese MMNs revealed a rightward bias for contour processing but a leftward hemispheric laterality for interval processing. In contrast, no asymmetries were observed in the English group. Collectively, our findings suggest tone-language experience sensitizes auditory brain mechanisms for the detection of subtle global/local pitch changes in the ongoing auditory stream and exaggerates functional asymmetries in pitch processing between cerebral hemispheres.

  20. [Posterior cerebral artery infarctions with possible interaction between hypoperfusion and embolism].

    PubMed

    Durand-Birchenall, J; Bugnicourt, J-M

    2013-12-01

    Although embolism and hypoperfusion may well occur concurrently in a non-negligible proportion of cerebral infarction patients, there is currently lack of proof, especially in the posterior circulation. Here, we are reporting on a case of multiple cerebral infarctions in a patient with neurofibromatosis type 1, multiple vascular abnormalities of the posterior cerebral circulation and intracranial artery occlusion. We hypothesize that cerebral blood flow impairment may have affected the clearance and destination of embolic particles.

  1. Cerebral blood flow variations in CNS lupus

    SciTech Connect

    Kushner, M.J.; Tobin, M.; Fazekas, F.; Chawluk, J.; Jamieson, D.; Freundlich, B.; Grenell, S.; Freemen, L.; Reivich, M. )

    1990-01-01

    We studied the patterns of cerebral blood flow (CBF), over time, in patients with systemic lupus erythematosus and varying neurologic manifestations including headache, stroke, psychosis, and encephalopathy. For 20 paired xenon-133 CBF measurements, CBF was normal during CNS remissions, regardless of the symptoms. CBF was significantly depressed during CNS exacerbations. The magnitude of change in CBF varied with the neurologic syndrome. CBF was least affected in patients with nonspecific symptoms such as headache or malaise, whereas patients with encephalopathy or psychosis exhibited the greatest reductions in CBF. In 1 patient with affective psychosis, without clinical or CT evidence of cerebral ischemia, serial SPECT studies showed resolution of multifocal cerebral perfusion defects which paralleled clinical recovery.

  2. Resting state EEG power, intra-hemisphere and inter-hemisphere coherence in bipolar disorder

    NASA Astrophysics Data System (ADS)

    Handayani, Nita; Khotimah, S. N.; Haryanto, F.; Arif, I.; Taruno, Warsito P.

    2017-02-01

    This paper examines the differences of EEG power and coherence between bipolar disorder patients and healthy subjects in the resting state. Observations are focused on the prefrontal cortex area by calculating intra-hemisphere and inter-hemisphere coherence. EEG data acquisition are conducted by using wireless Emotiv Epoc on AF3, AF4, FC5, FC6, F7 and F8 channels. The power spectral analysis shows that in bipolar disoder there is an increase of power in the delta, theta and beta frequencies, and power decrease in the alpha frequency. The coherence test results show that both intra-hemisphere and inter-hemisphere coherence in bipolar disorder patients are lower than healthy subjects. This shows the lack of brain synchronization in bipolar disorder patients.

  3. Atmospheric Teleconnections of Northern Hemisphere cooling to the Southern Hemisphere midlatitudes, and implications for Southern Ocean ventilation

    NASA Astrophysics Data System (ADS)

    Chiang, John; Lee, Shih-Yu; Matsumoto, Katsumi; Tokos, Kathy

    2010-05-01

    Recent marine proxy studies, most notably by Anderson et al. (2009), show intensification of wind-driven upwelling in the Southern Ocean during Heinrich events, and suggesting the possibility of robust atmospheric teleconnections from the Northern Hemisphere affecting the Southern Hemisphere midlatitude westerlies. We explore the latter hypothesis using simulations of an AGCM coupled to a reduced-gravity ocean, and with reference to current thinking regarding extratropical-tropical atmospheric dynamical linkages. When we simulate a Heinrich-like event in our model (by cooling the North Atlantic), we find a significant strengthening of the southern midlatitude westerlies, in particular during the austral winter (JJA), and in the South Pacific. The other pronounced climate change is a marked southward shift of the tropical rainbelt, indicating alteration of the Hadley circulation. Our analysis indicates that the teleconnection can be broken into two parts: first, the northern hemisphere cooling shifting the ITCZ southwards with a pronounced effect on the Hadley circulation (Lindzen and Hou 1988), and then the altered Hadley circulation in turn affecting the southern midlatitude westerlies through the former's control of the southern subtropical westerlies and subsequent effect on the eddy-driven midlatitude westerlies (Lee and Kim, 2003). The seasonal (JJA) and regional (South Pacific) preference of the teleconnection's effects can be explained in terms of the peculiarities of the regional atmospheric dynamics. As an aside, we also find that the growth or decay of the Laurentide ice sheet can also generate this type of north-south teleconnection, although the dynamics are somewhat different. With regards to possible implications for southern ocean ventilation and atmospheric CO2: we applied the wind changes we obtained in our AGCM 'Heinrich' simulation to a global biogeochemical model (the Minnesota Earth System Model for Ocean biogeochemistry), and found a ~20ppm

  4. Vesta's UV Lightcurve: Hemispheric Variation in Brightness and Spectral Reversal

    NASA Technical Reports Server (NTRS)

    Hendrix, Amanda R.; Vilas, Faith; Festou, Michael

    2003-01-01

    Spectra of asteroid 4 Vesta obtained in October 1990 with the International Ultraviolet Explorer are reanalyzed and reinterpreted. A large portion of the eastern hemisphere (based on the prime meridian definition of Thomas et al., 1997a) is darker at UV Wavelengths than much of the western hemisphere. The UV lightcurve is in contrast with the visible lightcurve, which shows that the eastern hemisphere is brighter than the western. These IUE spectra of Vesta thus may be evidence for the "spectral reversal." first seen on the Moon by Apollo 17. where the visibly brighter lunar highlands are darker than the maria at far-UV wavelengths. This effect was linked to space weathering when it was noted (Wagner et al., 1987) that the spectral reversal appears in the laboratory spectra of lunar soils but not powdered lunar rocks. We investigate Vesta's UV lightcurve and spectral reversal, and its possible connection with space weathering. The addition to grain coatings of small amounts of submicroscopic iron (SMFe) through vapor deposition causes drastic spectral changes at UV-visible wavelengths (Hapke, 2001). while the longer wavelength spectrum remains largely unaffected. Other laboratory results (e.g., Hiroi and Pieters, 1998) indicate that the UV-visible wavelength range is affected by simulated weathering processes in a manner similar to what is seen on Vesta. It is likely that Vesta has experienced relatively minor amounts of space weathering, as indicated by the spectral reversal, along with the subtle visible-near infrared weathering effects (e.g., Binzel et al., 1997).

  5. Choosing words: left hemisphere, right hemisphere, or both? Perspective on the lateralization of word retrieval

    PubMed Central

    Ries, Stephanie K.; Dronkers, Nina F.; Knight, Robert T.

    2015-01-01

    Language is considered to be one of the most lateralized human brain functions. Left hemisphere dominance for language has been consistently confirmed in clinical and experimental settings and constitutes one of the main axioms of neurology and neuroscience. However, functional neuroimaging studies are finding that the right hemisphere also plays a role in diverse language functions. Critically, the right hemisphere may also compensate for the loss or degradation of language functions following extensive stroke-induced damage to the left hemisphere. Here, we review studies that focus on our ability to choose words as we speak. Although fluidly performed in individuals with intact language, this process is routinely compromised in aphasic patients. We suggest that parceling word retrieval into its sub-processes—lexical activation and lexical selection—and examining which of these can be compensated for after left hemisphere stroke can advance the understanding of the lateralization of word retrieval in speech production. In particular, the domain-general nature of the brain regions associated with each process may be a helpful indicator of the right hemisphere's propensity for compensation. PMID:26766393

  6. Choosing words: left hemisphere, right hemisphere, or both? Perspective on the lateralization of word retrieval.

    PubMed

    Riès, Stéphanie K; Dronkers, Nina F; Knight, Robert T

    2016-04-01

    Language is considered to be one of the most lateralized human brain functions. Left hemisphere dominance for language has been consistently confirmed in clinical and experimental settings and constitutes one of the main axioms of neurology and neuroscience. However, functional neuroimaging studies are finding that the right hemisphere also plays a role in diverse language functions. Critically, the right hemisphere may also compensate for the loss or degradation of language functions following extensive stroke-induced damage to the left hemisphere. Here, we review studies that focus on our ability to choose words as we speak. Although fluidly performed in individuals with intact language, this process is routinely compromised in aphasic patients. We suggest that parceling word retrieval into its subprocesses-lexical activation and lexical selection-and examining which of these can be compensated for after left hemisphere stroke can advance the understanding of the lateralization of word retrieval in speech production. In particular, the domain-general nature of the brain regions associated with each process may be a helpful indicator of the right hemisphere's propensity for compensation.

  7. Bone age in cerebral palsy

    PubMed Central

    Miranda, Eduardo Régis de Alencar Bona; Palmieri, Maurício D'arc; de Assumpção, Rodrigo Montezuma César; Yamada, Helder Henzo; Rancan, Daniela Regina; Fucs, Patrícia Maria de Moraes Barros

    2013-01-01

    Objective To compare the chronological age and bone age among cerebral palsy patients in the outpatient clinic and its correlation with the type of neurological involvement, gender and functional status. Methods 401 patients with spastic cerebral palsy, and ages ranging from three months to 20 years old, submitted to radiological examination for bone age and analyzed by two independent observers according Greulich & Pyle. Results In the topographic distribution, there was a significant delay (p<0.005) in tetraparetic (17.7 months), hemiparetic (10.1 months), and diparetic patients (7.9 months). In the hemiparetic group, the mean bone age in the affected side was 96.88 months and the uncompromised side was 101.13 months (p<0.005). Regarding functional status, the ambulatory group showed a delay of 18.73 months in bone age (p<0.005). Comparing bone age between genders, it was observed a greater delay in males (13.59 months) than in females (9.63 months), but not statistically significant (p = 0.54). Conclusion There is a delay in bone age compared to chronological age influenced by the topography of spasticity, functional level and gender in patients with cerebral palsy. Level of Evidence IV, Case Series. PMID:24453693

  8. Knowledge and Strategies for Processing Lexical Metaphor after Right or Left Hemisphere Brain Damage.

    ERIC Educational Resources Information Center

    Tompkins, Connie A.

    1990-01-01

    The study assessed how unilateral right hemisphere brain damage (RHD) affects processing of metaphoric aspects of word meaning. RHD stroke patients (N=25) performed similarly to left-brain-damaged and normal subjects in the automatic condition and when provided with processing strategies. Both brain-damaged groups had difficulty developing…

  9. The representation of discourse in the two hemispheres: an individual differences investigation.

    PubMed

    Prat, Chantel S; Long, Debra L; Baynes, Kathleen

    2007-03-01

    Two experiments were conducted to investigate discourse representation in the two cerebral hemispheres as a function of reading skill. We used a lateralized visual-field procedure to compare left hemisphere (LH) and right hemisphere (RH) sensitivity to different discourse relations in readers with varying skill levels. In Experiment 1, we investigated two levels of discourse representation in memory: (a) the propositional representation and (b) the discourse model. We found that all readers were sensitive to propositional relations in the LH. In contrast, sensitivity to propositional relations in the RH increased as a function of reading skill. In addition, reading skill was positively related to topic relations in the LH, whereas it was negatively in the RH. In Experiment 2, we investigated propositional relations of different distances and again found that all readers were sensitive to propositional relations in the LH, whereas sensitivity to propositional relations in the RH was negatively related to reading skill. In general, reading skill appears to be associated with left-lateralized discourse representations.

  10. Multi-region hemispheric specialization differentiates human from nonhuman primate brain function.

    PubMed

    Wey, Hsiao-Ying; Phillips, Kimberley A; McKay, D Reese; Laird, Angela R; Kochunov, Peter; Davis, M Duff; Glahn, David C; Blangero, John; Duong, Timothy Q; Fox, Peter T

    2014-11-01

    The human behavioral repertoire greatly exceeds that of nonhuman primates. Anatomical specializations of the human brain include an enlarged neocortex and prefrontal cortex (Semendeferi et al. in Am J Phys Anthropol 114:224-241, 2001), but regional enlargements alone cannot account for these vast functional differences. Hemispheric specialization has long believed to be a major contributing factor to such distinctive human characteristics as motor dominance, attentional control and language. Yet structural cerebral asymmetries, documented in both humans and some nonhuman primate species, are relatively minor compared to behavioral lateralization. Identifying the mechanisms that underlie these functional differences remains a goal of considerable interest. Here, we investigate the intrinsic connectivity networks in four primate species (humans, chimpanzees, baboons, and capuchin monkeys) using resting-state fMRI to evaluate the intra- and inter- hemispheric coherences of spontaneous BOLD fluctuation. All three nonhuman primate species displayed lateralized functional networks that were strikingly similar to those observed in humans. However, only humans had multi-region lateralized networks, which provide fronto-parietal connectivity. Our results indicate that this pattern of within-hemisphere connectivity distinguishes humans from nonhuman primates.

  11. Hemispheric Asymmetry of Human Brain Anatomical Network Revealed by Diffusion Tensor Tractography

    PubMed Central

    Shu, Ni; Liu, Yaou; Duan, Yunyun; Li, Kuncheng

    2015-01-01

    The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. However, few studies have investigated the hemispheric asymmetries of the human brain from the perspective of the network model, and little is known about the asymmetries of the connection patterns of brain regions, which may reflect the functional integration and interaction between different regions. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 72 right-handed healthy adult subjects. We established the existence of structural connections between any pair of the 90 cortical and subcortical regions using deterministic tractography. To investigate the hemispheric asymmetries of the brain, statistical analyses were performed to reveal the brain regions with significant differences between bilateral topological properties, such as degree of connectivity, characteristic path length, and betweenness centrality. Furthermore, local structural connections were also investigated to examine the local asymmetries of some specific white matter tracts. From the perspective of both the global and local connection patterns, we identified the brain regions with hemispheric asymmetries. Combined with the previous studies, we suggested that the topological asymmetries in the anatomical network may reflect the functional lateralization of the human brain. PMID:26539535

  12. Hemispheric Asymmetry of Human Brain Anatomical Network Revealed by Diffusion Tensor Tractography.

    PubMed

    Shu, Ni; Liu, Yaou; Duan, Yunyun; Li, Kuncheng

    2015-01-01

    The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. However, few studies have investigated the hemispheric asymmetries of the human brain from the perspective of the network model, and little is known about the asymmetries of the connection patterns of brain regions, which may reflect the functional integration and interaction between different regions. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 72 right-handed healthy adult subjects. We established the existence of structural connections between any pair of the 90 cortical and subcortical regions using deterministic tractography. To investigate the hemispheric asymmetries of the brain, statistical analyses were performed to reveal the brain regions with significant differences between bilateral topological properties, such as degree of connectivity, characteristic path length, and betweenness centrality. Furthermore, local structural connections were also investigated to examine the local asymmetries of some specific white matter tracts. From the perspective of both the global and local connection patterns, we identified the brain regions with hemispheric asymmetries. Combined with the previous studies, we suggested that the topological asymmetries in the anatomical network may reflect the functional lateralization of the human brain.

  13. Cerebral Palsy (CP) Quiz

    MedlinePlus

    ... Submit Button Past Emails CDC Features Pop Quiz: Cerebral Palsy Language: English Español (Spanish) Recommend on Facebook Tweet ... Sandy is the parent of a child with cerebral palsy and the Board President of Gio’s Garden , a ...

  14. The Effects of Spatial Smoothing on Solar Magnetic Helicity and the Hemispheric Helicity Sign Rule

    NASA Astrophysics Data System (ADS)

    Koch Ocker, Stella; Petrie, Gordon

    2016-05-01

    The hemispheric sign rule for solar magnetic helicity, which states that negative/positive helicity occurs preferentially in the northern/southern hemisphere, provides clues to the causes of twisted, flaring magnetic fields. However, previous studies on the hemisphere rule may have been significantly affected by seeing from atmospheric turbulent motions. Using Hinode/SOT-SP data spanning from 2006 to 2012, we studied the effects of two important data processing steps that imitate the effects of atmospheric seeing: noise reduction by ignoring pixel values that are weaker than the estimated noise threshold, and Gaussian spatial smoothing. We applied these processing techniques to the helicity distribution maps for active regions NOAA 11158 and NOAA 11243, along with the average helicities of 36 active regions, in order to imitate and understand the effects of seeing from atmospheric turbulence. We found that rather than changing trends in the helicity distributions, Gaussian smoothing and noise reduction enhanced existing trends by pushing outliers towards the mean or removing them altogether. We also found that, when separated for weak and strong magnetic fields, the average helicities of the 36 active regions conformed to the hemisphere rule for weak field helicities and breached the rule for strong field helicities. In general, we found that data processing did not affect whether the hemisphere rule held for data taken from space-based instruments, and thus that seeing from atmospheric turbulence did not significantly affect previous studies' ground-based results on the hemisphere rule. This work was carried out through the National Solar Observatory Research Experiences for Undergraduates (REU) Program, which is funded by the National Science Foundation (NSF). The National Solar Observatory is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the NSF.

  15. Asymmetric auroral intensities in the Earth's Northern and Southern hemispheres

    NASA Astrophysics Data System (ADS)

    Laundal, K. M.; Østgaard, N.

    2009-07-01

    It is commonly assumed that the aurora borealis (Northern Hemisphere) and aurora australis (Southern Hemisphere) are mirror images of each other because the charged particles causing the aurora follow the magnetic field lines connecting the two hemispheres. The particles are believed to be evenly distributed between the two hemispheres, from the source region in the equatorial plane of the magnetosphere. Although it has been shown that similar auroral features in the opposite hemispheres can be displaced tens of degree in longitude and that seasonal effects can cause differences in global intensity, the overall auroral patterns were still similar. Here we report observations that clearly contradict the common assumption about symmetric aurora: intense spots are seen at dawn in the Northern summer Hemisphere, and at dusk in the Southern winter Hemisphere. The asymmetry is interpreted in terms of inter-hemispheric currents related to seasons, which have been predicted but hitherto had not been seen.

  16. Hemisphericity and Journalism--How Do Journalists Think?

    ERIC Educational Resources Information Center

    Vannatta, Bonnie Ann

    1981-01-01

    Reports on a study finding that journalists preferred a right brain hemisphere or integrated style of information processing. Proposes the further application of right-left brain hemisphere research in the field of journalism. (RL)

  17. FLAIR vascular hyperintensities and 4D MR angiograms for the estimation of collateral blood flow in anterior cerebral artery ischemia

    PubMed Central

    Maros, Maté; Lobsien, Donald; Michalski, Dominik; Groden, Christoph; Hoffmann, Karl-Titus; Förster, Alex

    2017-01-01

    Purpose To assess FLAIR vascular hyperintensities (FVH) and dynamic (4D) angiograms derived from perfusion raw data as proposed magnetic resonance (MR) imaging markers of leptomeningeal collateral circulation in patients with ischemia in the territory of the anterior cerebral artery (ACA). Methods Forty patients from two tertiary care university hospitals were included. Infarct volumes and perfusion deficits were manually measured on DWI images and TTP maps, respectively. FVH and collateral flow on 4D MR angiograms were assessed and graded as previously specified. Results Forty-one hemispheres were affected. Mean DWI lesion volume was 8.2 (± 13.9; range 0–76.9) ml, mean TTP lesion volume was 24.5 (± 17.2, range 0–76.7) ml. FVH were observed in 26/41 (63.4%) hemispheres. Significant correlations were detected between FVH and TTP lesion volume (ρ = 0.4; P<0.01) absolute (ρ = 0.37; P<0.05) and relative mismatch volume (ρ = 0.35; P<0.05). The modified ASITN/SIR score correlated inversely with DWI lesion volume (ρ = -0.58; P<0.01) and positively with relative mismatch (ρ = 0.29; P< 0.05). ANOVA of the ASITN/SIR score revealed significant inter-group differences for DWI (P<0.001) and TTP lesion volumes (P<0.05). No correlation was observed between FVH scores and modified ASITH/SIR scores (ρ = -0.16; P = 0.32). Conclusions FVH and flow patterns on 4D MR angiograms are markers of perfusion deficits and tissue at risk. As both methods did not show a correlation between each other, they seem to provide complimentary instead of redundant information. Previously shown evidence for the meaning of these specific MR signs in internal carotid and middle cerebral artery stroke seems to be transferrable to ischemic stroke in the ACA territory. PMID:28234996

  18. Interleukin-1 receptor antagonist decreases the number of necrotic neurons in rats with middle cerebral artery occlusion.

    PubMed Central

    Garcia, J. H.; Liu, K. F.; Relton, J. K.

    1995-01-01

    Marked increases in the brain expression of interleukin (IL)-1 have been reported in rats after permanent occlusion of a large cerebral artery. Interactions between endothelial cells and leukocytes have been implicated in the pathogenesis of several types of ischemic injury to the myocardium and other organs. In this study we asked whether inhibiting the effects of IL-1 would affect the outcome of an experimental brain infarct. Adult male Wistar rats (n = 13) with permanent occlusion of the middle cerebral artery were given IL-1 receptor antagonist. A second group (n = 13) with the same type of brain injury was given a placebo. A third group, subjected to a sham operation, was given either IL-1 receptor antagonist (n = 2) or a placebo (n = 2). Experiments were terminated after either 24 hours or 7 days. Compared with the control group, animals treated with IL-1 receptor antagonist improved their neurological score (P < 0.05), experienced less pronounced changes in body weight (P < 0.05), and had fewer necrotic neurons (P < 0.001) and fewer leukocytes in the ischemic hemisphere (P < 0.001) as well as a smaller area of pallor (P < 0.05) in the ischemis hemisphere. The results suggest that inhibiting the proinflammatory effects of IL-1 with a receptor antagonist is an effective way of influencing the leukocyte responses elicited by an arterial occlusion. Such leukocyte inhibition seemingly attenuates the number of necrotic neurons resulting from the occlusion of a large brain artery. Images Figure 4 Figure 6 Figure 8 PMID:7485410

  19. Mesoscale Temperature Fluctuations in the Southern Hemisphere Stratosphere

    NASA Technical Reports Server (NTRS)

    Gary, Bruce L.

    2008-01-01

    Isentrope surfaces in the Southern Hemisphere stratosphere reveal that air parcels undergo mesoscale temperature fluctuations that depend on latitude and season. The largest temperature fluctuations occur at high latitude winter, whereas the smallest fluctuations occur at high latitude summer. This is the same pattern found for the Northern Hemisphere stratosphere. However, the amplitude of the seasonal dependence in the Southern Hemisphere is only 37% of the Northern Hemisphere's seasonal amplitude.

  20. Simultaneous verbal and affective laterality effects.

    PubMed

    Bulman-Fleming, M B; Bryden, M P

    1994-07-01

    By analyzing the error scores of normal participants asked to identify a specific word spoken in a specific tone of voice (for example, the word "tower" spoken in a happy tone of voice), we have been able to demonstrate concurrent verbal and affective cerebral laterality effects in a dichotic listening task. The targets comprised the 16 possible combinations of four two-syllable words spoken in four different tones of voice. There were 128 participants equally divided between left- and right-handers, with equal numbers of each sex within each handedness group. Each participant responded to 144 trials on the dichotic task, and filled in the 32-item Waterloo Handedness Questionnaire. Analysis of false positive responses on the dichotic task (responding "yes" when only the verbal or only the affective component of the target was present, or when both components were present but were at opposite ears) indicated that significantly more errors were made when the verbal aspect of the target appeared at the right ear (left hemisphere) and the emotional aspect was at the left ear (right hemisphere) than when the reverse was the case. A single task has generated both effects, so that differences in participants' strategies or the way in which attention is biased cannot account for the results. While the majority of participants showed a right-ear advantage for verbal material and a left-ear advantage for nonverbal material, these two effects were not correlated, suggesting that independent mechanisms probably underly the establishment of verbal and affective processing. We found no significant sex or handedness effects, though left-handers were much more variable than were right-handers. There were no significant correlations between degree of handedness as measured on the handedness questionnaire and extent of lateralization of verbal or affective processing on the dichotic task. We believe that this general technique may be able to provide information as to the nature and

  1. Visual Hemispheric Specialization: A Computational Theory.

    DTIC Science & Technology

    1985-10-31

    Which is darker green, a Christmas tree or a frozen pea? Which is bigger, a tennis ball or an orange? Most people claim that they visualize the objects...evolved piecemeal, with new components being added, or old ones being modified, to work with those already available. A modularized system is easiest...nor for representing locations in absolute space. In most people , the right hemisphere appears to have become relatively specialized for these

  2. Quaternary glaciations in the Northern Hemisphere

    SciTech Connect

    Sibrava, V.; Bowen, D.Q.; Richmond, G.M.

    1987-01-01

    This volume presents the final report of Project 24 of the International Geological Correlation Programme. The publication is drawn from the contributions of leading individual scientist as well as from scientific research teams. It reflects the present state of knowledge of the Quaternary Glaciations in the Northern Hemisphere and their correlation in space and time, as well as providing a unique summary of climatic change.

  3. Right-hemisphere (spatial?) acalculia and the influence of neglect.

    PubMed

    Benavides-Varela, Silvia; Pitteri, Marco; Priftis, Konstantinos; Passarini, Laura; Meneghello, Francesca; Semenza, Carlo

    2014-01-01

    The present study aimed at exploring basic number and calculation abilities in right-hemisphere damaged patients (RHD), focusing primarily on one-digit orally presented tasks, which do not require explicit visuo-spatial abilities. Twenty-four non mentally-deteriorated RHD patients [12 with clinical neglect (RHDN+), 12 without clinical neglect (RHDN-)], and 12 healthy controls were included in the study. Participants were administered an ad hoc numerical battery assessing abilities such as counting, number magnitude comparison, writing and reading Arabic numerals and mental calculation, among others. Significant differences emerged among healthy controls and both the RHDN+ group and the RHDN- group, suggesting that the mathematical impairment of RHD patients does not necessarily correspond to the presence of left-neglect. A detailed analysis of the sub-tests of the battery evidenced expected differences among RHDN+ patients, RHDN- patients, and controls in writing and reading Arabic numerals. Crucially, differences between RHDN+ patients and controls were also found in tasks such as mental subtraction and mental multiplication, which do not require written visuo-spatial abilities. The present findings thus suggest that unilateral right hemisphere lesions may produce specific representational deficits that affect simple mental calculation, and not only the spatial arrangement of multi-digit written numbers as previously thought.

  4. Genetic biomarkers for brain hemisphere differentiation in Parkinson's Disease

    NASA Astrophysics Data System (ADS)

    Hourani, Mou'ath; Mendes, Alexandre; Berretta, Regina; Moscato, Pablo

    2007-11-01

    This work presents a study on the genetic profile of the left and right hemispheres of the brain of a mouse model of Parkinson's disease (PD). The goal is to characterize, in a genetic basis, PD as a disease that affects these two brain regions in different ways. Using the same whole-genome microarray expression data introduced by Brown et al. (2002) [1], we could find significant differences in the expression of some key genes, well-known to be involved in the mechanisms of dopamine production control and PD. The problem of selecting such genes was modeled as the MIN (α,β)—FEATURE SET problem [2]; a similar approach to that employed previously to find biomarkers for different types of cancer using gene expression microarray data [3]. The Feature Selection method produced a series of genetic signatures for PD, with distinct expression profiles in the Parkinson's model and control mice experiments. In addition, a close examination of the genes composing those signatures shows that many of them belong to genetic pathways or have ontology annotations considered to be involved in the onset and development of PD. Such elements could provide new clues on which mechanisms are implicated in hemisphere differentiation in PD.

  5. Metaplastic up-regulation of LTP in the rat visual cortex by monocular visual training: requirement of task mastery, hemispheric specificity, and NMDA-GluN2B involvement.

    PubMed

    Hager, A M; Gagolewicz, P J; Rodier, S; Kuo, M-C; Dumont, É C; Dringenberg, H C

    2015-05-07

    "Metaplasticity" is defined as an alteration of synaptic plasticity properties or mechanisms by a priming event without actual changes in synaptic strength. For example, visual discrimination training of rats leads to a facilitation of the subsequent induction of long-term potentiation (LTP) between the lateral geniculate nucleus (LGN) and the primary visual cortex (V1). Here, rats received visual discrimination training in a modified water maze, with one eye occluded during training to create monocular viewing conditions; 63% of rats acquired the task under these conditions. Following training, in vivo electrophysiology was used to examine LTP of field postsynaptic potentials (fPSPs) in V1 elicited by LGN stimulation. Rats that had successfully learned the task showed significantly greater LTP in the "trained V1" (contralateral to the open, trained eye) relative to the "untrained" hemisphere. Rats that underwent training but failed to acquire the task did not show this lateralized plasticity enhancement and had similar levels of LTP in both cerebral hemispheres. Cortical application of the NMDA receptor-GluN2B subunit antagonist Ro 25-6981 (2 mM) reversed the training-induced LTP facilitation without affecting LTP in the untrained V1. Whole-cell patch clamp recordings of V1 (layers II/III) pyramidal cells in vitro demonstrated that pharmacologically isolated NMDA currents exhibit a greater sensitivity to GluN2B blockade in the trained relative to the untrained V1. Together, these experiments reveal a surprising degree of anatomical (only in the hemisphere contralateral to the trained eye) and behavioral specificity (only in rats that mastered the task) for the effect of visual training to enhance LTP in V1. Further, cortical GluN2B subunits appear to be directly involved in this metaplastic facilitation of thalamocortical plasticity, suggesting that NMDA subunit composition or functioning is, at least in part, regulated by the exposure to behaviorally significant

  6. Flexible Contrast Gain Control in the Right Hemisphere

    ERIC Educational Resources Information Center

    Okubo, Matia; Nicholls, Michael E. R.

    2005-01-01

    This study investigates whether the right hemisphere has more flexible contrast gain control settings for the identification of spatial frequency. Right-handed participants identified 1 and 9 cycles per degree sinusoidal gratings presented either to the left visual field-right hemisphere (LVF-RH) or the right visual field-left hemisphere (RVF-LH).…

  7. Teaching ESL from the Right Hemisphere of the Brain.

    ERIC Educational Resources Information Center

    Curt, Carmen Judith Nine

    Based on the idea that the brain consists of hemispheres which control different types of behavior, this paper argues that the Puerto Rican school system is deteriorating because its emphasis on left hemisphere (quantitative) activities does not synchronize with Puerto Rico's cultural orientation toward the right hemisphere (qualitative…

  8. The Influence of Context on Hemispheric Recruitment during Metaphor Processing

    ERIC Educational Resources Information Center

    Diaz, Michele T.; Hogstrom, Larson J.

    2011-01-01

    Although the left hemisphere's prominence in language is well established, less emphasis has been placed on possible roles for the right hemisphere. Behavioral, patient, and neuroimaging research suggests that the right hemisphere may be involved in processing figurative language. Additionally, research has demonstrated that context can modify…

  9. Evidence for Right Hemisphere Phonology in a Backward Masking Task

    ERIC Educational Resources Information Center

    Halderman, Laura K.

    2011-01-01

    The extent to which orthographic and phonological processes are available during the initial moments of word recognition within each hemisphere is under specified, particularly for the right hemisphere. Few studies have investigated whether each hemisphere uses orthography and phonology under constraints that restrict the viewing time of words and…

  10. Brain Hemisphere Dominance: Building the Whole-Brain Singer

    ERIC Educational Resources Information Center

    Boyd, Amanda R.

    2012-01-01

    The concept of brain hemisphere dominance serves as the basis for many educational learning theories. The dominant brain hemisphere guides the learning process, but both hemispheres are necessary for true learning to take place. This treatise outlines and analyzes the dominance factor, a learning theory developed by Dr. Carla Hannaford, which…

  11. Hemispheric Asymmetries in the Activation and Monitoring of Memory Errors

    ERIC Educational Resources Information Center

    Giammattei, Jeannette; Arndt, Jason

    2012-01-01

    Previous research on the lateralization of memory errors suggests that the right hemisphere's tendency to produce more memory errors than the left hemisphere reflects hemispheric differences in semantic activation. However, all prior research that has examined the lateralization of memory errors has used self-paced recognition judgments. Because…

  12. Tectonic Evolution of the Eastern Hemisphere of Mars

    NASA Technical Reports Server (NTRS)

    Pounders, E.; Anderson, R. C.; Dohm, J. M.; Haldemann, A. F. C.; Golombek, M. P.

    2002-01-01

    The magmatic-tectonic history of Mars is largely dominated by the Tharsis magmatic complex of the western hemisphere and the Elysium rise of the eastern hemisphere. In order to address the history of Mars, the tectonic history of the eastern hemisphere must also be unraveled. Additional information is contained in the original extended abstract.

  13. Bio-inspired hemispherical compound eye camera

    NASA Astrophysics Data System (ADS)

    Xiao, Jianliang; Song, Young Min; Xie, Yizhu; Malyarchuk, Viktor; Jung, Inhwa; Choi, Ki-Joong; Liu, Zhuangjian; Park, Hyunsung; Lu, Chaofeng; Kim, Rak-Hwan; Li, Rui; Crozier, Kenneth B.; Huang, Yonggang; Rogers, John A.

    2014-03-01

    Compound eyes in arthropods demonstrate distinct imaging characteristics from human eyes, with wide angle field of view, low aberrations, high acuity to motion and infinite depth of field. Artificial imaging systems with similar geometries and properties are of great interest for many applications. However, the challenges in building such systems with hemispherical, compound apposition layouts cannot be met through established planar sensor technologies and conventional optics. We present our recent progress in combining optics, materials, mechanics and integration schemes to build fully functional artificial compound eye cameras. Nearly full hemispherical shapes (about 160 degrees) with densely packed artificial ommatidia were realized. The number of ommatidia (180) is comparable to those of the eyes of fire ants and bark beetles. The devices combine elastomeric compound optical elements with deformable arrays of thin silicon photodetectors, which were fabricated in the planar geometries and then integrated and elastically transformed to hemispherical shapes. Imaging results and quantitative ray-tracing-based simulations illustrate key features of operation. These general strategies seem to be applicable to other compound eye devices, such as those inspired by moths and lacewings (refracting superposition eyes), lobster and shrimp (reflecting superposition eyes), and houseflies (neural superposition eyes).

  14. Meteor showers of the southern hemisphere

    NASA Astrophysics Data System (ADS)

    Molau, Sirko; Kerr, Steve

    2014-04-01

    We present the results of an exhaustive meteor shower search in the southern hemisphere. The underlying data set is a subset of the IMO Video Meteor Database comprising 50,000 single station meteors obtained by three Australian cameras between 2001 and 2012. The detection technique was similar to previous single station analysis. In the data set we find 4 major and 6 minor northern hemisphere meteor showers, and 12 segments of the Antihelion source (including the Northern and Southern Taurids and six streams from the MDC working list). We present details for 14 southern hemisphere showers plus the Centaurid and Puppid-Velid complex, with the η Aquariids and the Southern δ Aquariids being the strongest southern showers. Two of the showers (θ^2 Sagittariids and τ Cetids) were previously unknown and have received preliminary designations by the MDC. Overall we find that the fraction of southern meteor showers south of -30deg declination (roughly 25%) is clearly smaller than the fraction of northern meteor showers north of +30deg declination (more than 50%) obtained in our previous analysis.

  15. Hemispheric asymmetry of visual scene processing in the human brain: evidence from repetition priming and intrinsic activity.

    PubMed

    Stevens, W Dale; Kahn, Itamar; Wig, Gagan S; Schacter, Daniel L

    2012-08-01

    Asymmetrical specialization of cognitive processes across the cerebral hemispheres is a hallmark of healthy brain development and an important evolutionary trait underlying higher cognition in humans. While previous research, including studies of priming, divided visual field presentation, and split-brain patients, demonstrates a general pattern of right/left asymmetry of form-specific versus form-abstract visual processing, little is known about brain organization underlying this dissociation. Here, using repetition priming of complex visual scenes and high-resolution functional magnetic resonance imaging (MRI), we demonstrate asymmetrical form specificity of visual processing between the right and left hemispheres within a region known to be critical for processing of visual spatial scenes (parahippocampal place area [PPA]). Next, we use resting-state functional connectivity MRI analyses to demonstrate that this functional asymmetry is associated with differential intrinsic activity correlations of the right versus left PPA with regions critically involved in perceptual versus conceptual processing, respectively. Our results demonstrate that the PPA comprises lateralized subregions across the cerebral hemispheres that are engaged in functionally dissociable yet complementary components of visual scene analysis. Furthermore, this functional asymmetry is associated with differential intrinsic functional connectivity of the PPA with distinct brain areas known to mediate dissociable cognitive processes.

  16. Cerebral asymmetry: a quantitative, multifactorial, and plastic brain phenotype.

    PubMed

    Rentería, Miguel E

    2012-06-01

    The longitudinal fissure separates the human brain into two hemispheres that remain connected through the corpus callosum. The left and the right halves of the brain resemble each other, and almost every structure present in one side has an equivalent structure in the other. Despite this exceptional correspondence, the two hemispheres also display important anatomical differences and there is marked lateralization of certain cognitive and motor functions such as language and handedness. However, the mechanisms that underlie the establishment of these hemispheric specializations, as well as their physiological and behavioral implications, remain largely unknown. Thanks to recent advances in neuroimaging, a series of studies documenting variation in symmetry and asymmetry as a function of age, gender, brain region, and pathological state, have been published in the past decade. Here, we review evidence of normal and atypical cerebral asymmetry, and the factors that influence it at the macrostructural level. Given the prominent role that cerebral asymmetry plays in the organization of the brain, and its possible implication in neurodevelopmental and psychiatric conditions, further research in this area is anticipated.

  17. Performing Permanent Distal Middle Cerebral with Common Carotid Artery Occlusion in Aged Rats to Study Cortical Ischemia with Sustained Disability.

    PubMed

    Wayman, Christina; Duricki, Denise A; Roy, Lisa A; Haenzi, Barbara; Tsai, Shi-Yen; Kartje, Gwendolyn; Beech, John S; Cash, Diana; Moon, Lawrence

    2016-02-23

    Stroke typically occurs in elderly people with a range of comorbidities including carotid (or other arterial) atherosclerosis, high blood pressure, obesity and diabetes. Accordingly, when evaluating therapies for stroke in animals, it is important to select a model with excellent face validity. Ischemic stroke accounts for 80% of all strokes, and the majority of these occur in the territory of the middle cerebral artery (MCA), often inducing infarcts that affect the sensorimotor cortex, causing persistent plegia or paresis on the contralateral side of the body. We demonstrate in this video a method for producing ischemic stroke in elderly rats, which causes sustained sensorimotor disability and substantial cortical infarcts. Specifically, we induce permanent distal middle cerebral artery occlusion (MCAO) in elderly female rats by using diathermy forceps to occlude a short segment of this artery. The carotid artery on the ipsilateral side to the lesion was then permanently occluded and the contralateral carotid artery was transiently occluded for 60 min. We measure the infarct size using structural T2-weighted magnetic resonance imaging (MRI) at 24 hr and 8 weeks after stroke. In this study, the mean infarct volume was 4.5% ± 2.0% (standard deviation) of the ipsilateral hemisphere at 24 hr (corrected for brain swelling using Gerriet's equation, n = 5). This model is feasible and clinically relevant as it permits the induction of sustained sensorimotor deficits, which is important for the elucidation of pathophysiological mechanisms and novel treatments.

  18. Performing Permanent Distal Middle Cerebral with Common Carotid Artery Occlusion in Aged Rats to Study Cortical Ischemia with Sustained Disability

    PubMed Central

    Roy, Lisa A.; Haenzi, Barbara; Tsai, Shi-Yen; Kartje, Gwendolyn; Beech, John S.; Cash, Diana; Moon, Lawrence

    2016-01-01

    Stroke typically occurs in elderly people with a range of comorbidities including carotid (or other arterial) atherosclerosis, high blood pressure, obesity and diabetes. Accordingly, when evaluating therapies for stroke in animals, it is important to select a model with excellent face validity. Ischemic stroke accounts for 80% of all strokes, and the majority of these occur in the territory of the middle cerebral artery (MCA), often inducing infarcts that affect the sensorimotor cortex, causing persistent plegia or paresis on the contralateral side of the body. We demonstrate in this video a method for producing ischemic stroke in elderly rats, which causes sustained sensorimotor disability and substantial cortical infarcts. Specifically, we induce permanent distal middle cerebral artery occlusion (MCAO) in elderly female rats by using diathermy forceps to occlude a short segment of this artery. The carotid artery on the ipsilateral side to the lesion was then permanently occluded and the contralateral carotid artery was transiently occluded for 60 min. We measure the infarct size using structural T2-weighted magnetic resonance imaging (MRI) at 24 hr and 8 weeks after stroke. In this study, the mean infarct volume was 4.5% ± 2.0% (standard deviation) of the ipsilateral hemisphere at 24 hr (corrected for brain swelling using Gerriet’s equation, n = 5). This model is feasible and clinically relevant as it permits the induction of sustained sensorimotor deficits, which is important for the elucidation of pathophysiological mechanisms and novel treatments. PMID:26967269

  19. Sex differences in brain proteomes of neuron-specific STAT3-null mice after cerebral ischemia/reperfusion.

    PubMed

    Di Domenico, Fabio; Casalena, Gabriella; Jia, Jia; Sultana, Rukhsana; Barone, Eugenio; Cai, Jian; Pierce, William M; Cini, Chiara; Mancuso, Cesare; Perluigi, Marzia; Davis, Catherine M; Alkayed, Nabil J; Butterfield, D Allan; Butterfield, Allan D

    2012-05-01

    Signal transduction and activator of transcription-3 (STAT3) plays an important role in neuronal survival, regeneration and repair after brain injury. We previously demonstrated that STAT3 is activated in brain after cerebral ischemia specifically in neurons. The effect was sex-specific and modulated by sex steroids, with higher activation in females than males. In the current study, we used a proteomics approach to identify downstream proteins affected by ischemia in male and female wild-type (WT) and neuron-specific STAT3 knockout (KO) mice. We established four comparison groups based on the transgenic condition and the hemisphere analyzed, respectively. Moreover, the sexual variable was taken into account and male and female animals were analyzed independently. Results support a role for STAT3 in metabolic, synaptic, structural and transcriptional responses to cerebral ischemia, indeed the adaptive response to ischemia/reperfusion injury is delayed in neuronal-specific STAT3 KO mice. The differences observed between males and females emphasize the importance of sex-specific neuronal survival and repair mechanisms, especially those involving antioxidant and energy-related activities, often caused by sex hormones.

  20. Whose side are you on: does serotonin preferentially activate the right hemisphere and norepinephrine the left?

    PubMed

    Fitzgerald, Paul J

    2012-08-01

    Serotonin (5-HT) and norepinephrine (NE) innervate both the left and right hemispheres of the brain, but whether they affect lateralization of function is unknown. This paper concisely examines evidence that these two neurotransmitters differentially affect the two hemispheres, and puts forth the novel hypothesis 5-HT preferentially activates the right hemisphere (RH) and NE the left hemisphere (LH). The principal lines of evidence comprise studies of: (1) 5-HT and NE level measurement, (2) receptor binding, (3) functional brain imaging, (4) dichotic listening, and (5) electroencephalography and evoked potentials. In assessing these 5 lines, emphasis is placed on studies of pharmaceutical drugs that affect the 5-HT and NE systems. While all of the data do not support the hypothesis, they are generally consistent with it, or a variant of the hypothesis that there is a bias toward 5-HT preferentially activating a majority of brain areas or functions in the RH, and NE a majority of LH areas or functions. If this hypothesis, or a variant of it, is correct, it may be relevant to understanding the physiological basis of neuropsychiatric disorders that could involve dysfunction in brain monoaminergic systems, as well as understanding potential lateralization of the effects of drugs that act on these systems.

  1. White matter integrity in right hemisphere predicts pitch-related grammar learning.

    PubMed

    Loui, Psyche; Li, H Charles; Schlaug, Gottfried

    2011-03-15

    White matter plays an important role in various domains of cognitive function. While disruptions in white matter are known to affect many domains of behavior and cognition, the ability to acquire grammatical regularities has been mostly linked to the left hemisphere, perhaps due to its dependence on linguistic stimuli. The role of white matter in the right hemisphere in grammar acquisition is yet unknown. Here we show for the first time that in the domain of pitch, intact white matter connectivity in right-hemisphere analogs of language areas is important for grammar learning. A pitch-based artificial grammar learning task was conducted on subjects who also underwent diffusion tensor imaging. Probabilistic tractography using seed regions of interest in the right inferior frontal gyrus and right middle temporal gyrus showed positive correlations between tract volume and learning performance. Furthermore, significant correlations were observed between learning performance and FA in white matter underlying the supramarginal gyrus, corresponding to the right temporal-parietal junction of the arcuate fasciculus. The control task of recognition did not correlate with tract volume or FA, and control tracts in the left hemisphere did not correlate with behavioral performance. Results show that the right ventral arcuate fasciculus is important in pitch-based artificial grammar learning, and that brain structures subserving learning may be tied to the hemisphere that processes the stimulus more generally.

  2. Are reptile and amphibian species younger in the Northern Hemisphere than in the Southern Hemisphere?

    PubMed

    Dubey, Sylvain; Shine, R

    2012-01-01

    A previous analysis of molecular phylogenies suggested that intraspecific diversification had occurred more recently in temperate-zone Northern Hemisphere reptiles and amphibians than in Southern Hemisphere taxa. Here, we test potential explanations for this pattern. We examined published phylogenetic analyses, derived from genetic sequence data, to generate two estimates of the age of species: (i) the oldest intraspecific diversification event within each taxon and (ii) the inferred timing of the split between two sister species. The timing of splits between species shows the same pattern as splits within species, and thus may be due to climatically driven cladogenic and extinction events or may be an artefact of differing levels of taxonomic knowledge about the fauna. Current rates of species descriptions suggest that many more taxa remain to be described in the Southern Hemisphere than the Northern Hemisphere; for that bias to fully explain our results on species age differences, the proportion of undescribed Southern taxa would need to be ≥ 12% in reptiles and ≥ 51% in anurans. For reptiles, taxonomic ignorance plausibly explains the apparent difference in mean age of species between the Southern and Northern Hemispheres; but this explanation can apply to amphibians only if a vast number of Southern taxa remain to be described.

  3. Hemispheric asymmetries in processing L1 and L2 idioms: effects of salience and context.

    PubMed

    Cieślicka, Anna B; Heredia, Roberto R

    2011-03-01

    This study investigates the contribution of the left and right hemispheres to the comprehension of bilingual figurative language and the joint effects of salience and context on the differential cerebral involvement in idiom processing. The divided visual field and the lexical decision priming paradigms were employed to examine the activation of salient and nonsalient ambiguous idiom interpretations (i.e., literal vs. non-literal) in the two hemispheres. Literally plausible ambiguous idioms, L1 (Polish) and L2 (English), were embedded in unconstraining ambiguous (e.g., I knew he kept an ace up his sleeve) or constraining unambiguous context clearly favoring their conventional idiomatic interpretation (e.g., The debating president kept an ace up his sleeve). Idioms were presented centrally, followed by laterally presented targets related to the figurative (e.g., GAIN) or literal (e.g., SHIRT) meaning of the idiom and displayed at Interstimulus Intervals (ISIs) of 0 ms (Experiment 1), 300 ms (Experiment 2), and 800 ms (Experiment 3). Results indicate that context and salience effects are significantly modulated by the language (native vs. nonnative) of the stimulus materials being presented to each hemisphere. Literal facilitation was found for L2 idioms in all three ISI conditions, which supports the notion of the special status that literal meanings of L2 idioms enjoy in the course of their processing by nonnative language users. No significant differences were found between the right and left hemispheres in regards to their sensitivity to contextual constraints. Results are discussed in terms of the Graded Salience Hypothesis and the Fine/Coarse Coding Theory.

  4. Mobile phone emission increases inter-hemispheric functional coupling of electroencephalographic α rhythms in epileptic patients.

    PubMed

    Vecchio, Fabrizio; Tombini, Mario; Buffo, Paola; Assenza, Giovanni; Pellegrino, Giovanni; Benvenga, Antonella; Babiloni, Claudio; Rossini, Paolo Maria

    2012-05-01

    It has been reported that GSM electromagnetic fields (GSM-EMFs) of mobile phones modulate - after a prolonged exposure - inter-hemispheric synchronization of temporal and frontal resting electroencephalographic (EEG) rhythms in normal young and elderly subjects (Vecchio et al., 2007, 2010). Here we tested the hypothesis that this can be even more evident in epileptic patients, who typically suffer from abnormal mechanisms governing synchronization of rhythmic firing of cortical neurons. Eyes-closed resting EEG data were recorded in ten patients affected by focal epilepsy in real and sham exposure conditions. These data were compared with those obtained from 15 age-matched normal subjects of the previous reference studies. The GSM device was turned on (45 min) in the "GSM" condition and was turned off (45 min) in the other condition ("sham"). The mobile phone was always positioned on the left side in both patients and control subjects. Spectral coherence evaluated the inter-hemispheric synchronization of EEG rhythms at the following frequency bands: delta (about 2-4 Hz), theta (about 4-6 Hz), alpha1 (about 6-8 Hz), alpha2 (about 8-10 Hz), and alpha3 (about 10-12 Hz). The effects on the patients were investigated comparing the inter-hemispheric EEG coherence in the epileptic patients with the control group of subjects evaluated in the previous reference studies. Compared with the control subjects, epileptic patients showed a statistically significant higher inter-hemispheric coherence of temporal and frontal alpha rhythms (about 8-12 Hz) in the GSM than "Sham" condition. These results suggest that GSM-EMFs of mobile phone may affect inter-hemispheric synchronization of the dominant (alpha) EEG rhythms in epileptic patients. If confirmed by future studies on a larger group of epilepsy patients, the modulation of the inter-hemispheric alpha coherence due to the GSM-EMFs could have clinical implications and be related to changes in cognitive-motor function.

  5. Assessment of the hand in cerebral palsy

    PubMed Central

    Bhardwaj, Praveen; Sabapathy, S. Raja

    2011-01-01

    Cerebral palsy is the musculoskeletal manifestation of a nonprogressive central nervous system lesion that usually occurs due to a perinatal insult to the brain. Though the cerebral insult is static the musculoskeletal pathology is progressive. Some patients with cerebral palsy whose hands are affected can be made better by surgery. The surgical procedures as such are not very technically demanding but the assessment, decision-making, and selecting the procedures for the given patient make this field challenging. When done well, the results are rewarding not only in terms of improvement in hand function but also in appearance and personal hygiene, which leads to better self-image and permits better acceptance in the society. This article focuses on the clinical examination, patient selection, and decision-making while managing these patients. PMID:22022045

  6. Geomagnetic Field Response at Southern and Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    Chandel, Babita

    Geomagnetic Field Response at Southern and Northern Hemisphere Babita Chandel, Shailendra Saini, Sneha Yadav,S.K.Vijay and A.K.Gwal Space Science Laboratory, Department of Physics, Barkatullah University, Bhopal-462026, India ABSTRACT: This paper represents the geomagnetic field response at Southern Hemisphere (MAITRI) and Northern Hemisphere (TROMSO). The Indian Antarctic Station MAITRI is located at geomagnetic Long. (66.030, 53.210) where as TROMSO is at geomagnetic Long. (66.030, 53.210). We studied the behaviour of geomagnetic field with respect to geomagnetic storms at both the stations TROMSO and MAITRI. It was observed that at Southern Hemisphere there is more variation in winter as compared to the summer season, where as in Northern Hemisphere the variations are more in summer as compared to winter. As in the Northern hemisphere the magnetospheric plasma is strongly turbulized in summer and in Southern hemisphere the magentospheric plasma is strongly turbulized in winter.

  7. Croll revisited: Why is the northern hemisphere warmer than the southern hemisphere?

    NASA Astrophysics Data System (ADS)

    Kang, Sarah M.; Seager, Richard; Frierson, Dargan M. W.; Liu, Xiaojuan

    2015-03-01

    The question of why, in the annual-mean, the northern hemisphere (NH) is warmer than the southern hemisphere (SH) is addressed, revisiting an 1870 paper by James Croll. We first show that ocean is warmer than land in general which, acting alone, would make the SH, with greater ocean fraction, warmer. Croll was aware of this and thought it was caused by greater specific humidity and greenhouse trapping over ocean than over land. However, for any given temperature, it is shown that greenhouse trapping is actually greater over land. Instead, oceans are warmer than land because of the smaller surface albedo. However, hemispheric differences in planetary albedo are negligible because the impact of differences in land-sea fraction are offset by the SH ocean and land reflecting more than their NH counterparts. In the absence of a role for albedo differences it is shown that, in agreement with Croll, northward cross-equatorial ocean heat transport (X-OHT) is critical for the warmer NH. This is examined in a simple box model based on the energy budget of each hemisphere. The hemispheric difference forced by X-OHT is enhanced by the positive water vapor-greenhouse feedback, and is partly compensated by the southward atmospheric energy transport. Due to uncertainties in the ocean data, a range of X-OHT is considered. A X-OHT of larger than 0.5 PW is needed to explain the warmer NH solely by X-OHT. For smaller X-OHT, a larger basic state greenhouse trapping in the NH, conceived as imposed by continental geometry, needs to be imposed. Numerical experiments with a GCM coupled to a slab ocean provide evidence that X-OHT is fundamentally important in determining the hemispheric differences in temperature. Therefore, despite some modifications to his theory, analysis of modern data confirms Croll's 140-year-old theory that the warmer NH is partly because of northward X-OHT.

  8. The effect of hemisphere specific remediation strategies on the academic performance outcome of children with ADD/ADHD.

    PubMed

    Leisman, Gerry; Melillo, Robert; Thum, Sharon; Ransom, Mark A; Orlando, Michael; Tice, Christopher; Carrick, Frederick R

    2010-01-01

    The development and normal function of the cerebrum is largely dependent on sub-cortical structures, such as the cerebellum and basal ganglia. Dysfunction in these areas can affect both the nonspecific arousal system and information transfer in the brain. Dysfunction of this sort often results in motor and sensory symptoms commonly seen in children with ADD/ADHD. These brain regions have been reported to be underactive, with that underactivity restricted to the right or left side of the sub-cortical and cortical regions. An imbalance of activity or arousal of one side of the cortex can result in a functional disconnection similar to that seen in split-brain patients. Since ADD/ADHD children exhibit deficient performance on tests thought to measure perceptual laterality, evidence of weak laterality or failure to develop laterality has been found across various modalities (auditory, visual, tactile) resulting in abnormal cerebral organization and associated dysfunctional specialization needed for lateralized processing of language and non-language function. This study examines groups of ADD/ADHD elementary school children from first through sixth grade. All participants were administered all the subtests of the Wechsler Individual Achievement Tests, the Brown Parent Questionnaire, and given objective performance measures on tests of motor and sensory coordinative abilities (interactive metronome). Results measured after a 12-week remediation program aimed at increasing the activity of the hypothesized underactive right hemisphere function, yielded significant improvement of greater than two years in grade level in all domains except in mathematical reasoning. Results are discussed in the context of the concept of functional disconnectivity in ADD/ADHD children.

  9. Inter-Hemispherical Currents for Realistic Model of Ionospheric Conductivity

    NASA Astrophysics Data System (ADS)

    Lyatsky, S.; Khazanov, G. V.

    2013-12-01

    We present results of modeling of the global 3-D ionosphere-magnetosphere current system including in addition to the R1 and R2 field-aligned currents also inter-hemispherical currents. The inter-hemispherical currents flow between Northern and Southern conjugate ionospheres in case of a North-South asymmetry in ionospheric conductivity in two hemispheres. These currents link together the ionospheric currents in two hemispheres, so the currents observed in one hemisphere can provide us with information about currents in the opposite hemisphere, which is especially important when their magnitude can not be obtained from direct observation (e.g., in Antarctica). In this study, we investigate the generation of the inter-hemispherical currents for several distributions of ionospheric conductivity in two hemispheres including a simplified model of ionospheric conductivity, which is important for better understanding of the expected distribution and magnitude of these currents, and a more realistic model of ionospheric conductivity, which is observed during magnetospheric substorms, when the geometry of the inter-hemispherical currents is more complicated. Simulation results show that the inter-hemispherical currents during substorms could play a very significant role, and neglecting these currents does not allow obtaining the correct picture of 3-D magnetosphere-ionosphere current system. These currents are an important part of 3-D field-aligned current system, and they are especially strong during summer-winter months, when they are comparable in magnitude with the R2 currents (about ~0.5 MA). Inter-hemispherical currents map. Left panel is related to Northern hemisphere, right panel to Southern. R1 and R2 currents are not shown; their locations are indicated by the red and blue dashed circles, respectively. The inter-hemispherical currents appear inside the auroral zone in the region of conductivity gradient. The currents in both hemispheres are equal in magnitude and

  10. HUBBLE SPOTS NORTHERN HEMISPHERIC CLOUDS ON URANUS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Using visible light, astronomers for the first time this century have detected clouds in the northern hemisphere of Uranus. The newest images, taken July 31 and Aug. 1, 1997 with NASA Hubble Space Telescope's Wide Field and Planetary Camera 2, show banded structure and multiple clouds. Using these images, Dr. Heidi Hammel (Massachusetts Institute of Technology) and colleagues Wes Lockwood (Lowell Observatory) and Kathy Rages (NASA Ames Research Center) plan to measure the wind speeds in the northern hemisphere for the first time. Uranus is sometimes called the 'sideways' planet, because its rotation axis is tipped more than 90 degrees from the planet's orbit around the Sun. The 'year' on Uranus lasts 84 Earth years, which creates extremely long seasons - winter in the northern hemisphere has lasted for nearly 20 years. Uranus has also been called bland and boring, because no clouds have been detectable in ground-based images of the planet. Even to the cameras of the Voyager spacecraft in 1986, Uranus presented a nearly uniform blank disk, and discrete clouds were detectable only in the southern hemisphere. Voyager flew over the planet's cloud tops near the dead of northern winter (when the northern hemisphere was completely shrouded in darkness). Spring has finally come to the northern hemisphere of Uranus. The newest images, both the visible-wavelength ones described here and those taken a few days earlier with the Near Infrared and Multi-Object Spectrometer (NICMOS) by Erich Karkoschka (University of Arizona), show a planet with banded structure and detectable clouds. Two images are shown here. The 'aqua' image (on the left) is taken at 5,470 Angstroms, which is near the human eye's peak response to wavelength. Color has been added to the image to show what a person on a spacecraft near Uranus might see. Little structure is evident at this wavelength, though with image-processing techniques, a small cloud can be seen near the planet's northern limb (rightmost

  11. Hubble Spots Northern Hemispheric Clouds on Uranus

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Using visible light, astronomers for the first time this century have detected clouds in the northern hemisphere of Uranus. The newest images, taken July 31 and Aug. 1, 1997 with NASA Hubble Space Telescope's Wide Field and Planetary Camera 2, show banded structure and multiple clouds. Using these images, Dr. Heidi Hammel (Massachusetts Institute of Technology) and colleagues Wes Lockwood (Lowell Observatory) and Kathy Rages (NASA Ames Research Center) plan to measure the wind speeds in the northern hemisphere for the first time.

    Uranus is sometimes called the 'sideways' planet, because its rotation axis tipped more than 90 degrees from the planet's orbit around the Sun. The 'year' on Uranus lasts 84 Earth years, which creates extremely long seasons - winter in the northern hemisphere has lasted for nearly 20 years. Uranus has also been called bland and boring, because no clouds have been detectable in ground-based images of the planet. Even to the cameras of the Voyager spacecraft in 1986, Uranus presented a nearly uniform blank disk, and discrete clouds were detectable only in the southern hemisphere. Voyager flew over the planet's cloud tops near the dead of northern winter (when the northern hemisphere was completely shrouded in darkness).

    Spring has finally come to the northern hemisphere of Uranus. The newest images, both the visible-wavelength ones described here and those taken a few days earlier with the Near Infrared and Multi-Object Spectrometer (NICMOS) by Erich Karkoschka (University of Arizona), show a planet with banded structure and detectable clouds.

    Two images are shown here. The 'aqua' image (on the left) is taken at 5,470 Angstroms, which is near the human eye's peak response to wavelength. Color has been added to the image to show what a person on a spacecraft near Uranus might see. Little structure is evident at this wavelength, though with image-processing techniques, a small cloud can be seen near the planet's northern limb

  12. Has Northern Hemisphere Heat Flow Been Underestimated?

    NASA Astrophysics Data System (ADS)

    Gosnold, W. D.; Majorowicz, J.; Safanda, J.; Szewczyk, J.

    2005-05-01

    We present three lines of evidence to suggest the hypothesis that heat flow in the northern hemisphere may have been underestimated by 15 to 60 percent in shallow wells due to a large post-glacial warming signal. First, temperature vs. depth (T-z) measurements in parts of Europe and North America show a systematic increase in heat flow with depth. This phenomenon is best recognized in analyses of deep (greater than 2km) boreholes in non-tectonic regions with normal to low background heat flow. In Europe, the increase in heat flow with depth has been observed by analysis of more than 1500 deep boreholes located throughout the Fennoscandian Shield, East European Platform, Danish Basin, Germany, Czech Republic, and Poland. There are significantly fewer deep boreholes in North America, but the increase in heat flow with depth appears in a suite of 759 sites in the IHFC Global Heat Flow Database for the region east of the Rocky Mountains and north of latitude 40 N. Second, surface heat flow values in southern hemisphere shields average approximately 50 mWm-2, but surface heat flow values in northern hemisphere shields average 33 mWm-2. Unless crustal radioactivity or mantle heat flow or both factors are greater in southern hemisphere continents, there is no reason for the northern and southern shield areas having similar ages to have different heat flow values. Third, two recently published surface heat flow maps show anomalously low heat flow in the Canadian Shield in a pattern that is coincident with the Wisconsinan ice sheet. The coincidence of low heat flow and ice accumulation has no geophysical basis, thus the coincidence may suggest the existence of a transient signal caused by a warming event. Recent studies of heat flow in North America indicate that in several sites, the ice base temperature was close to the pressure melting point. We hypothesize that there may have been cold ice-free periods during the Pleistocene that would account for the apparent colder

  13. Cerebral Contusions and Lacerations

    MedlinePlus

    ... Sports-Related Concussion Diffuse Axonal Injury Intracranial Hematomas Skull Fracture Cerebral contusions are bruises of the brain, ... object or pushed-in bone fragment from a skull fracture. Motor vehicle crashes and blows to the ...

  14. Cerebral amyloid angiopathy

    MedlinePlus

    ... 911) if you have sudden loss of movement , sensation, vision, or speech. Alternative Names Amyloidosis - cerebral; CAA; Congophilic angiopathy Images Amyloidosis on the fingers Arteries of the brain References Kase CS, Shoamanesh A. Intracerebral hemorrhage. In: Daroff ...

  15. Phenological changes in the southern hemisphere.

    PubMed

    Chambers, Lynda E; Altwegg, Res; Barbraud, Christophe; Barnard, Phoebe; Beaumont, Linda J; Crawford, Robert J M; Durant, Joel M; Hughes, Lesley; Keatley, Marie R; Low, Matt; Morellato, Patricia C; Poloczanska, Elvira S; Ruoppolo, Valeria; Vanstreels, Ralph E T; Woehler, Eric J; Wolfaardt, Anton C

    2013-01-01

    Current evidence of phenological responses to recent climate change is substantially biased towards northern hemisphere temperate regions. Given regional differences in climate change, shifts in phenology will not be uniform across the globe, and conclusions drawn from temperate systems in the northern hemisphere might not be applicable to other regions on the planet. We conduct the largest meta-analysis to date of phenological drivers and trends among southern hemisphere species, assessing 1208 long-term datasets from 89 studies on 347 species. Data were mostly from Australasia (Australia and New Zealand), South America and the Antarctic/subantarctic, and focused primarily on plants and birds. This meta-analysis shows an advance in the timing of spring events (with a strong Australian data bias), although substantial differences in trends were apparent among taxonomic groups and regions. When only statistically significant trends were considered, 82% of terrestrial datasets and 42% of marine datasets demonstrated an advance in phenology. Temperature was most frequently identified as the primary driver of phenological changes; however, in many studies it was the only climate variable considered. When precipitation was examined, it often played a key role but, in contrast with temperature, the direction of phenological shifts in response to precipitation variation was difficult to predict a priori. We discuss how phenological information can inform the adaptive capacity of species, their resilience, and constraints on autonomous adaptation. We also highlight serious weaknesses in past and current data collection and analyses at large regional scales (with very few studies in the tropics or from Africa) and dramatic taxonomic biases. If accurate predictions regarding the general effects of climate change on the biology of organisms are to be made, data collection policies focussing on targeting data-deficient regions and taxa need to be financially and logistically

  16. Hemispheric asymmetry: contributions from brain imaging.

    PubMed

    Hugdahl, Kenneth

    2011-09-01

    A series of studies using functional and structural magnetic resonance imaging, including diffusion tensor imaging measures also, to elucidate the aspects of hemispheric asymmetry are reviewed. It is suggested that laterality evolved as a response to the demands of language and the need for air-based communication which may have necessitated a division of labor between the hemispheres in order to avoid having duplicate copies in both the hemispheres that would increase processing redundancy. This would have put pressure on brain structures related to the evolution of language and speech, such as the left peri-Sylvian region. MRI data are provided showing structural and functional asymmetry in this region of the brain and how fibers connecting the right and left peri-Sylvian regions pass through the corpus callosum. It is further suggested that the so-called Yakelovian-torque, i.e., the twisting of the brain along the longitudinal axis, with the right frontal and left occipital poles protruding beyond the corresponding left and right sides, was necessary for the expansion of the left peri-Sylvian region and the right occipito-parietal regions subserving the processing of spatial relations. Functional magnetic resonance imaging data related to sex differences for visuo-spatial processing are presented showing enhanced right-sided activation in posterior parts of the brain in both sexes, and frontal activation including Broca's area in the female group only, suggesting that males and females use different strategies when solving a cognitive task. The paper ends with a discussion of the role of the corpus callosum in laterality and the role played by structural asymmetry in understanding corresponding functional asymmetry. WIREs Cogni Sci 2011 2 461-478 DOI: 10.1002/wcs.122 For further resources related to this article, please visit the WIREs website.

  17. Cerebral proliferative angiopathy: Clinical, angiographic features and literature review

    PubMed Central

    Liu, Peng; Lv, Xianli; Lv, Ming

    2016-01-01

    Purpose Here we present our experience with five cerebral proliferative angiopathy (CPA) patients to better delineate the clinical and angiographic features as well as the treatment selection of this disease. Methods Between October 2008 and October 2012, five consecutive patients diagnosed with CPA were admitted to our department in our hospital. All the five patients received magnetic resonance imaging, digital subtraction angiography, and positron emission computed tomography (PET) to definitively confirm this disease. We also collected 15 previously published instances of CPA to analyze the characteristics of this rare entity. Results As to the five patients, three were female and two were male, between the ages of 4 and 52 years with a mean age of 24.8 ± 20.6 years. The PET results showed that perfusion was decreased over the affected hemispheres in all five patients. As to the treatment, only one patient received encephalo-duro-arterio-synangiosis (EDAS) revascularization surgery. The other four patients were conservatively observed. During the follow-up period (range 3–6 years, mean 4 ± 1.9 years), the patient who underwent EDAS surgery manifested relief of clinical symptoms. In the conservative series, the symptoms in two patients aggravated and suffered permanent neurologic deficits. Conclusion CPA is a rare entity. Natural history has showed this disease is not stable and may progress at a certain time point. The EDAS procedure may be a treatment for CPA-related oligemia since there is currently little data and follow-up available. PMID:26472638

  18. The genus Platychara from the Western Hemisphere

    USGS Publications Warehouse

    Peck, R.E.; Forester, R.M.

    1979-01-01

    The systematics of four species belonging to the genus Platychara (Charophyta) from the Western Hemisphere is discussed. Three of the species, as defined herein, occur in Cretaceous and Paleocene rocks from Mexico through South America. The type species, P. compressa (Peck and Reker) Grambast, also of Cretaceous and Paleocene age, is herein restricted to deposits north of Mexico. These latter restrictions geographically separate P. compressa and P. perlata as presently defined but the relationship between these two species is still uncertain. A new species, P. grambastii, is proposed for specimens from Maestrichtian sediments in Jamaica. ?? 1979.

  19. Quantitative assessment of regional cerebral blood flow by dynamic susceptibility contrast-enhanced MRI, without the need for arterial blood signals

    NASA Astrophysics Data System (ADS)

    Enmi, Jun-ichiro; Kudomi, Nobuyuki; Hayashi, Takuya; Yamamoto, Akihide; Iguchi, Satoshi; Moriguchi, Tetsuaki; Hori, Yuki; Koshino, Kazuhiro; Zeniya, Tsutomu; Shah, Nadim Jon; Yamada, Naoaki; Iida, Hidehiro

    2012-12-01

    In dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI), an arterial input function (AIF) is usually obtained from a time-concentration curve (TCC) of the cerebral artery. This study was aimed at developing an alternative technique for reconstructing AIF from TCCs of multiple brain regions. AIF was formulated by a multi-exponential function using four parameters, and the parameters were determined so that the AIF curves convolved with a model of tissue response reproduced the measured TCCs for 20 regions. Systematic simulations were performed to evaluate the effects of possible error sources. DSC-MRI and positron emission tomography (PET) studies were performed on 14 patients with major cerebral artery occlusion. Cerebral blood flow (CBF) images were calculated from DSC-MRI data, using our novel method alongside conventional AIF estimations, and compared with those from 15O-PET. Simulations showed that the calculated CBF values were sensitive to variations in the assumptions regarding cerebral blood volume. Nevertheless, AIFs were reasonably reconstructed for all patients. The difference in CBF values between DSC-MRI and PET was -2.2 ± 7.4 ml/100 g/min (r = 0.55, p < 0.01) for our method, versus -0.2 ± 8.2 ml/100 g/min (r = 0.47, p = 0.01) for the conventional method. The difference in the ratio of affected to unaffected hemispheres between DSC-MRI and PET was 0.07 ± 0.09 (r = 0.82, p < 0.01) for our method, versus 0.07 ± 0.09 (r = 0.83, p < 0.01) for the conventional method. The contrasts in CBF images from our method were the same as those from the conventional method. These findings suggest the feasibility of assessing CBF without arterial blood signals.

  20. Locus of control and cerebral asymmetry.

    PubMed

    De Brabander, B; Boone, C; Gerits, P

    1992-08-01

    Data about the lack of synchronism of flexor carpi ulnaris peak EMG values of bimanual reactions during a semantic and during a visuospatial discrimination reaction time task are reported. The effects of type of task as well as the presence or absence of an unexpected stimulus preceding the reaction stimulus on lack of synchronism clearly depend upon the locus of control of the subjects, as measured on Rotter's I-E scale. On the basis of several arguments it is proposed that the measure of lack of synchronism reflects in an opposite sense the amount of dopaminergic activation or motor readiness in the sense in which Pribram and McGuinness in 1975 and Tucker and Williamson in 1984 have defined these concepts. The results for 15 women and 18 men show that more internally oriented subjects are more activated by a semantic task and by an unexpected preparatory stimulus in this type of task than more externally oriented subjects. The opposite appears to hold on the visuospatial task and unexpected preparatory stimuli therein. Together with earlier findings about reaction times and a number of relevant findings in the literature, the results are interpreted as indicative of basic differences in asymmetric tonic activation of the cerebral hemispheres between more internally and more externally oriented subjects. A model is proposed to explain phasic activating effects which ensue when tonically more left- or right-activated subjects perform left- or right-hemisphere tasks and when supplementary irrelevant stimuli are received.

  1. Nanomedicine in cerebral palsy.

    PubMed

    Balakrishnan, Bindu; Nance, Elizabeth; Johnston, Michael V; Kannan, Rangaramanujam; Kannan, Sujatha

    2013-01-01

    Cerebral palsy is a chronic childhood disorder that can have diverse etiologies. Injury to the developing brain that occurs either in utero or soon after birth can result in the motor, sensory, and cognitive deficits seen in cerebral palsy. Although the etiologies for cerebral palsy are variable, neuroinflammation plays a key role in the pathophysiology of the brain injury irrespective of the etiology. Currently, there is no effective cure for cerebral palsy. Nanomedicine offers a new frontier in the development of therapies for prevention and treatment of brain injury resulting in cerebral palsy. Nanomaterials such as dendrimers provide opportunities for the targeted delivery of multiple drugs that can mitigate several pathways involved in injury and can be delivered specifically to the cells that are responsible for neuroinflammation and injury. These materials also offer the opportunity to deliver agents that would promote repair and regeneration in the brain, resulting not only in attenuation of injury, but also enabling normal growth. In this review, the current advances in nanotechnology for treatment of brain injury are discussed with specific relevance to cerebral palsy. Future directions that would facilitate clinical translation in neonates and children are also addressed.

  2. Design and Fabrication of Micro Hemispheric Shell Resonator with Annular Electrodes

    PubMed Central

    Wang, Renxin; Bai, Bing; Feng, Hengzhen; Ren, Ziming; Cao, Huiliang; Xue, Chenyang; Zhang, Binzhen; Liu, Jun

    2016-01-01

    Electrostatic driving and capacitive detection is widely used in micro hemispheric shell resonators (HSR). The capacitor gap distance is a dominant factor for the initial capacitance, and affects the driving voltage and sensitivity. In order to decrease the equivalent gap distance, a micro HSR with annular electrodes fabricated by a glassblowing method was developed. Central and annular cavities are defined, and then the inside gas drives glass softening and deformation at 770 °C. While the same force is applied, the deformation of the hemispherical shell is about 200 times that of the annular electrodes, illustrating that the deformation of the electrodes will not affect the measurement accuracy. S-shaped patterns on the annular electrodes and internal-gear-like patterns on the hemispherical shell can improve metal malleability and avoid metal cracking during glass expansion. An arched annular electrode and a hemispheric shell are demonstrated. Compared with HSR with a spherical electrode, the applied voltage could be reduced by 29%, and the capacitance could be increased by 39%, according to theoretical and numerical calculation. The surface roughness of glass after glassblowing was favorable (Rq = 0.296 nm, Ra = 0.217 nm). In brief, micro HSR with an annular electrode was fabricated, and its superiority was preliminarily confirmed. PMID:27897977

  3. Cognitive correlates of hemispheric performance on dichotic tasks.

    PubMed

    Johnson, R C; Green, P; Ahern, F M; Cole, R E

    Older (age 50+) adults were tested twice on three measures of dichotic memory and once on three measures of cognition. Internal consistencies of all three measures generally were adequate. However, test-retest reliabilities, by ear of presentation, were comparatively low for the three dichotic measures. A measure of vocabulary (a left hemisphere dominant cognitive ability) was related to performance on most dichotic tasks. Years of education (an index of left hemisphere mediated crystallized intelligence) was related to performance on left but not right hemisphere function on two of three dichotic tasks. Performance on tests of spatial ability was related to performance on left ear/right hemisphere but not right ear/left hemisphere function on two of three dichotic memory tasks. Individual differences in accuracy of recall and recognition of stimuli presented via dichotic tasks to the right ear/left hemisphere and the left ear/right hemisphere appear to have different cognitive correlates. Right hemisphere performance on dichotic tasks generally shows a significant negative association with age, as did performance on right hemisphere dominant cognitive tasks. On the other hand, most measures of left hemisphere performance showed no decline associated with age.

  4. Complementary hemispheric specialization for word and accent detection.

    PubMed

    Berman, Steven M; Mandelkern, Mark A; Phan, Hao; Zaidel, Eran

    2003-06-01

    When we hear a familiar word pronounced in a foreign accent, which parts of the brain identify the word and which identify the accent? Here we present converging evidence from PET blood flow, event-related scalp potentials, and behavioral responses during dichotic listening, showing homologous and complementary hemispheric specialization for word and accent detection. Accuracy of detecting target words was greater when stimuli were presented to the right ear, indicating left hemisphere specialization, with no ear advantage for detecting target accents. Detection of words also produced increased blood flow in a left frontal area associated with motor and phonetic processing, and a left temporal area associated with semantic memory. Homologous areas of the right hemisphere, together with right prefrontal and precuneus regions, showed increased blood flow during detection of accents. Separate analyses for each detection task indicated that voxels whose activity maximally correlated with accuracy were in the left hemisphere for word detection, but in the right hemisphere for accent detection. Voxels whose activity maximally correlated with inaccuracy were in the opposite hemisphere for both tasks, strengthening the interpretation that between-task differences in brain activation are related to lateralized specializations for task performance. ERP waveforms and reaction times suggested that greater left hemisphere activation during word detection preceded greater right hemisphere activation during accent detection. The results are interpreted as supporting left hemisphere specialization for extraction of the linguistic, phonetic, and semantic information contained in speech, and right hemisphere specialization for pragmatics, the social context of linguistic communication.

  5. PET studies of changes in cerebral blood flow and oxygen metabolism after unilateral microembolization of the brain in anesthetized dogs.

    PubMed

    Weyne, J; De Ley, G; Demeester, G; Vandecasteele, C; Vermeulen, F L; Donche, H; Deman, J

    1987-01-01

    Cerebral blood flow and oxygen metabolism have been measured with the steady-state oxygen-15 technique and positron emission tomography in anesthetized dogs. Regional microembolization was induced by infusing Sephadex particles (diameter, 40 micron) into one of the common carotid arteries. In the first series of experiments, 2.5 mg Sephadex was infused, and the dogs were examined within 3-4 hours after embolization. In a second series 0.55 mg Sephadex was infused, and the dogs were examined either in the first 3-4 hours or 24-48 hours after embolization. Cerebral blood flow, oxygen extraction ratio, and cerebral oxygen utilization were measured at 3 PCO2 levels. In the acute experiments, cerebral oxygen utilization in the embolized hemisphere was 6 (0.55 mg Sephadex) and 25% (2.5 mg Sephadex) lower than on the contralateral side. While cerebral blood flow was symmetrically distributed in normocapnia and hypocapnia, it was 9 (0.55 mg Sephadex) and 35% (2.5 mg Sephadex) lower in the embolized hemisphere during hypercapnia. In normocapnia and hypocapnia the lower oxygen utilization in the embolized hemisphere was characterized by a lower oxygen extraction ratio, and in hypercapnia by an unchanged (0.55 mg Sephadex) or by a higher (2.5 mg Sephadex) extraction ratio. The different effect on oxygen extraction ratio in the control and embolized hemispheres resulted in images of uncoupling between perfusion and oxygen demand that varied according to the PCO2. The experiments also showed a fall in cerebral blood flow in the embolized hemisphere after 3-4 hours, indicating delayed hypoperfusion. After 24-48 hours, blood flow was about 10% higher in the embolized hemisphere, and this was observed at the 3 PCO2 levels, while the oxygen extraction ratio was systematically lower. Oxygen utilization in the embolized hemisphere was depressed to practically the same extent as in acute experiments. It can be concluded that between 4 and 24 hours after microembolization the cerebral

  6. Inter-hemispheric asymmetry of Pedersen conductance

    NASA Astrophysics Data System (ADS)

    Deng, Y.; Lu, Y.; Sheng, C.; Yue, X.

    2015-12-01

    Ionospheric conductance is very important to the magnetosphere-ionosphere coupling in the high latitude region, since it connects the polar cap potential with the currents. Meanwhile, the altitudinal distribution of Pederson conductance gives us a rough idea about the altitudinal distribution of Joule heating at high latitudes. Based on the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites observations of electron density profiles from 2009-2014, Pedersen conductivity has been calculated. A climatologic study of the height-integrated Pedersen conductivities in both E (100-150 km) and F (150-600 km) regions and their ratio in different seasons, solar and geomagnetic conditions have been conducted. A significant inter-hemispheric asymmetry is identified in the seasonal variation. Meanwhile, the conductance in both regions and the conductance ratio show a strong dependence on F10.7 and Ap indices. This result will strongly help our understanding of the inter-hemispheric difference in the high-latitude electrodynamics.

  7. Interannual Variability and Trends of Extratropical Ozone, Part II: Southern Hemisphere. Part 2; Southern Hemisphere

    NASA Technical Reports Server (NTRS)

    Yung, Y. L.

    2008-01-01

    A principal component analysis (PCA) is applied to the Southern Hemisphere (SH) total column ozone following the method established for analyzing the data in the Northern Hemisphere (NH) in a companion paper. The interannual variability (IAV) of extratropical O-3 in the SH is characterized by four main modes, which account for 75% of the total variance. The first two leading modes are approximately zonally symmetric and relate to the Southern Hemisphere annular mode and the quasi-biennial oscillation. The third and fourth modes exhibit wavenumber-1 structures. Contrary to the Northern Hemisphere, the third and fourth are nor related to stationary waves. Similar results obtained for the 30 100-hPa geopotential thickness.The decreasing O3 trend in the SH is captured in the first mode. The largest trend is at the South Pole, with value similar to-2 Dobson Units (DU)/yr. Both the spatial pattern and trends in the column ozone are captured by the Goddard Earth Observation System chemistry-climate model (GEOS-CCM) in the SH.

  8. Structural integrity of the contralesional hemisphere predicts cognitive impairment in ischemic stroke at three months.

    PubMed

    Dacosta-Aguayo, Rosalia; Graña, Manuel; Fernández-Andújar, Marina; López-Cancio, Elena; Cáceres, Cynthia; Bargalló, Núria; Barrios, Maite; Clemente, Immaculada; Monserrat, Pere Toran; Sas, Maite Alzamora; Dávalos, Antoni; Auer, Tibor; Mataró, Maria

    2014-01-01

    After stroke, white matter integrity can be affected both locally and distally to the primary lesion location. It has been shown that tract disruption in mirror's regions of the contralateral hemisphere is associated with degree of functional impairment. Fourteen patients suffering right hemispheric focal stroke (S) and eighteen healthy controls (HC) underwent Diffusion Weighted Imaging (DWI) and neuropsychological assessment. The stroke patient group was divided into poor (SP; n = 8) and good (SG; n = 6) cognitive recovery groups according to their cognitive improvement from the acute phase (72 hours after stroke) to the subacute phase (3 months post-stroke). Whole-brain DWI data analysis was performed by computing Diffusion Tensor Imaging (DTI) followed by Tract Based Spatial Statistics (TBSS). Assessment of effects was obtained computing the correlation of the projections on TBSS skeleton of Fractional Anisotropy (FA) and Radial Diffusivity (RD) with cognitive test results. Significant decrease of FA was found only in right brain anatomical areas for the S group when compared to the HC group. Analyzed separately, stroke patients with poor cognitive recovery showed additional significant FA decrease in several left hemisphere regions; whereas SG patients showed significant decrease only in the left genu of corpus callosum when compared to the HC. For the SG group, whole brain analysis revealed significant correlation between the performance in the Semantic Fluency test and the FA in the right hemisphere as well as between the performance in the Grooved Pegboard Test (GPT) and the Trail Making Test-part A and the FA in the left hemisphere. For the SP group, correlation analysis revealed significant correlation between the performance in the GPT and the FA in the right hemisphere.

  9. Structural Integrity of the Contralesional Hemisphere Predicts Cognitive Impairment in Ischemic Stroke at Three Months

    PubMed Central

    Dacosta-Aguayo, Rosalia; Graña, Manuel; Fernández-Andújar, Marina; López-Cancio, Elena; Cáceres, Cynthia; Bargalló, Núria; Barrios, Maite; Clemente, Immaculada; Monserrat, Pere Toran; Sas, Maite Alzamora; Dávalos, Antoni

    2014-01-01

    After stroke, white matter integrity can be affected both locally and distally to the primary lesion location. It has been shown that tract disruption in mirror’s regions of the contralateral hemisphere is associated with degree of functional impairment. Fourteen patients suffering right hemispheric focal stroke (S) and eighteen healthy controls (HC) underwent Diffusion Weighted Imaging (DWI) and neuropsychological assessment. The stroke patient group was divided into poor (SP; n = 8) and good (SG; n = 6) cognitive recovery groups according to their cognitive improvement from the acute phase (72 hours after stroke) to the subacute phase (3 months post-stroke). Whole-brain DWI data analysis was performed by computing Diffusion Tensor Imaging (DTI) followed by Tract Based Spatial Statistics (TBSS). Assessment of effects was obtained computing the correlation of the projections on TBSS skeleton of Fractional Anisotropy (FA) and Radial Diffusivity (RD) with cognitive test results. Significant decrease of FA was found only in right brain anatomical areas for the S group when compared to the HC group. Analyzed separately, stroke patients with poor cognitive recovery showed additional significant FA decrease in several left hemisphere regions; whereas SG patients showed significant decrease only in the left genu of corpus callosum when compared to the HC. For the SG group, whole brain analysis revealed significant correlation between the performance in the Semantic Fluency test and the FA in the right hemisphere as well as between the performance in the Grooved Pegboard Test (GPT) and theTrail Making Test-part A and the FA in the left hemisphere. For the SP group, correlation analysis revealed significant correlation between the performance in the GPT and the FA in the right hemisphere. PMID:24475078

  10. Human brain response to visual stimulus between lower/upper visual fields and cerebral hemispheres.

    PubMed

    Lee, Bumsuk; Kaneoke, Yoshiki; Kakigi, Ryusuke; Sakai, Yasujiro

    2009-11-01

    We studied the human brain response to visual stimulation in which a square area was randomly presented in upper and lower visual fields (VFs). Seven normal volunteers carried out a contrast-based visual search task. Magnetic responses were detected in the bilateral parietal regions at 200-250 ms after stimulus onset. We compared the response latencies and strengths of the essential single sensor and root mean square (RMS) of the regions. The former evaluates the strength of neural activity with relatively high spatial resolution, while the latter evaluates the global neural activity. The single sensor and RMS latencies for the lower left VF were significantly longer than that for the upper left (paired t-test, P<0.05). The strengths did not differ between the upper and lower left VFs. There was no significant difference in latency or strength between the upper right and lower right VFs. These findings suggest that only left VF has different response properties in the upper versus lower VF, and that both local and global extrastriate activities are responsible for this anisotropy.

  11. Assessment of the Relationship between Asymmetry in Cerebral Hemisphere Arousal and Perceptual Asymmetry

    DTIC Science & Technology

    1988-06-01

    like the dying runner of Marathon, it had just enough strength to deliver its message. And it was a historic one: the mysterious, distant planet Uranus ,l...violent past. Waiting astronomers basked in their midwinter’s night dream. The mission to Uranus , its slender rings and giant Shakesperian moons...Oberon and Titania , was humankind’s first close look at the seventh planet in our solar system and its last for the millennium. Though some findings were

  12. Individual and Joint Contributions of the Cerebral Hemispheres to Language Comprehension

    ERIC Educational Resources Information Center

    Wlotko, Edward Wesley

    2009-01-01

    Normal language comprehension requires contributions from and cooperation of many parts of the brain, ranging from sensory areas that receive the initial physical input, through frontal and temporal areas associated with oft-characterized language subprocesses, to brain areas involved in perspective-taking and social cognition; thus a network of…

  13. State of synapses of the cortex of cerebral hemispheres on gamma-irradiation

    SciTech Connect

    Gaidamakin, N.A.; Ushakov, I.B.

    1989-11-01

    In adult rats with developing neurological disorders we detected destructive changes in most of the synapses of the brain sensorimotor cortex 1.6-4.3 h after a single dose of gamma-irradiation (200 Gy). All functionally important parts on the axonal and dendritic sides of the synapses had undergone changes: mitochondria, synaptic vesicles, pre- and postsynaptic membranes, synaptic complexes, and subsynaptic consolidations, axonal and dendritic plasma, and their inclusions. These changes possibly cause disconnection of the neurons and provide a structural basis for neurological deficiencies following a high substantial ionizing radiation.

  14. Speaking with a Single Cerebral Hemisphere: fMRI Language Organization after Hemispherectomy in Childhood

    ERIC Educational Resources Information Center

    Liegeois, Frederique; Connelly, Alan; Baldeweg, Torsten; Vargha-Khadem, Faraneh

    2008-01-01

    Speech-related fMRI activation was examined in six hemispherectomy patients (three left LX, three right RX, four with congenital and two with late-acquired hemiplegia) operated in childhood for the relief of drug-resistant epilepsy. Although the temporal and sensorimotor pattern of activation was similar to that found in neurologically intact…

  15. Neutral glycolipid and ganglioside composition of type-1 and type-2 astrocytes from rat cerebral hemisphere.

    PubMed

    Murakami, K; Asou, H; Adachi, T; Takagi, T; Kunimoto, M; Saito, H; Uyemura, K

    1999-02-01

    We reported previously that the major gangliosides in primary mixed-type astrocyte cultures are GM3 and GD3. To obtain more information regarding the exact distribution of glycosphingolipids in different types of astrocytes, we established a line of type-1 astrocytes that are characterized by a Ran-2 positive, broad flat morphology, and by the absence of binding to A2B5 antibodies. We also purified O-2A progenitor cells by immunopanning and cultured them in the presence of 10% newborn calf serum. They differentiated into type-2 astrocytes that were identified by immunostaining for each of GD3, A2B5, and GFAP. Using these cell cultures, we demonstrate that the major gangliosides were GM3 in type-1 astrocytes and GM3 and GD3 in type-2 astrocytes. In addition, a set of neutral glycolipids was identified based on the HP-TLC migration properties of CMH, CDH, CTH, and Glob, but the component distribution of these glycolipids is related to that of glycolipids of astrocytes. A marked increase in the expression of CTH and Glob was shown in type-2 astrocytes. The amount of neutral glycolipid-sugar was higher in the type-2 astrocytes than in the type-1 astrocytes. These results suggest that the increase in the total glycosphingolipid content and the change in the neutral glycolipid composition produced by type-2 astrocytes may be related to their biological functions and the cellular compositions.

  16. Posaconazole responsive cerebral aspergillosis in an immunocompetent adult.

    PubMed

    Ellenbogen, Jonathan Richard; Waqar, Mueez; Denning, David W; Cooke, Richard P D; Skinner, Derek W; Lesser, Tristram; Javadpour, Mohsen

    2014-10-01

    Cerebral aspergillosis is a rare manifestation of invasive aspergillosis that usually affects immunocompromised patients. There are few treatment options for recurrent disease and experiences with immunocompetent patients are lacking. We report the clinical course of an immunocompetent patient with recurrent cerebral aspergillosis, following initial treatment with burr hole aspiration and voriconazole, who showed remarkable response to posaconazole. The patient remains clinically well with no evidence of recurrence on MRI 7 years following diagnosis. To our knowledge this is the first reported experience with posaconazole in an immunocompetent patient with cerebral aspergillosis.

  17. Hemispheric Asymmetry of Supplementary Motor Area Proper: A Functional Connectivity Study of the Motor Network.

    PubMed

    Dinomais, Mickael; Chinier, Eva; Richard, Isabelle; Ricalens, Emmanuel; Aubé, Christophe; N'Guyen The Tich, Sylvie; Ter Minassian, Aram

    2016-01-01

    Cerebral asymmetry is a common feature of human functions. However, there are discrepancies in the literature about functional hemispheric asymmetries in the supplementary motor area (SMA), specifically in the posterior part (SMA-proper). We used resting state functional connectivity MRI to investigate the left-right asymmetries of the functional networks associated with primary motor cortex (M1) and SMA-proper using a "seed"-based correlation analysis in 30 healthy right-handed subjects. We showed that left M1 was more connected with areas involved in the motor system than right M1, and that right SMA-proper had more functional connections than its left counterpart. Our results are in agreement with a leftward asymmetry for M1 connectivity, whereas there is a rightward asymmetry of the SMA-proper connectivity.

  18. Isotopic source signatures for atmospheric lead: the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Bollhöfer, A.; Rosman, K. J. R.

    2000-10-01

    Aerosols collected between 1994 and 1999 at more than 70 different sites affecting the Southern Hemisphere have been measured for their 206Pb/ 207Pb, 208Pb/ 207Pb and 206Pb/ 204Pb ratios and Pb concentrations. Lower ratios are found at the southern tips of Africa, Australia and South America probably due to the supply of alkyllead from a common supplier such as Associated Octel. The ratios increase in a northerly direction probably due to a changing market share in alkyllead or an increasing industrial Pb contribution. The geographical variations in isotopic signatures made it possible to broadly characterize the different regions that influence the Southern Hemisphere. Brazil and Argentina exhibited 206Pb/ 207Pb, 208Pb/ 207Pb and 206Pb/ 204Pb ratios in aerosols of 1.141-1.184, 2.416-2.442 and 17.77-18.57, respectively. Mexican aerosols had values of 1.188-1.197, 2.452-2.463 and 18.46-18.73. Aerosols sampled in Chile had low ratios in the South of 1.063-1.094, 2.337-2.373 and 16.46-17.13 which increased in a northerly direction. Emissions from South Africa were characterized by ratios 1.067-1.090, 2.340-2.358 and 16.53-16.99. In 1994-1995 Australia and New Zealand had ratios of 1.060-1.193, 2.324-2.445 and 16.08-18.54. In 1997 however, the range was narrower: 1.072-1.112, 2.342-2.398 and 16.55-17.36, respectively. These isotopic signatures are potentially useful for tracing sources of pollution and the movement of air-masses on a global scale.

  19. [Study of regional cerebral glucose metabolism, in man, while awake or asleep, by positron emission tomography].

    PubMed

    Franck, G; Salmon, E; Poirrier, R; Sadzot, B; Franco, G

    1987-03-01

    Measurements of regional cerebral glucose uptake by the 18F-fluorodeoxyglucose technique (18FDG) and positron emission tomography (PET) along with polygraph recordings were made serially during relaxed wakefulness and different stages of nocturnal sleep in two right-handed normal volunteers. During stage III-IV sleep, values declined diffusely in both hemispheric regions (-31%), thalamus (-33%), cerebellum (-33%) and brain stem (-25%). During paradoxical sleep regional values increased diffusely compared with slow wave sleep. Compared to wakefulness, regional metabolic values seemed to increase but the results were more variable from one volunteer to the other. These preliminary data indicate important regional alterations in cerebral metabolism between sleep states.

  20. Acute Multiple Cerebral Infarction in a Patient with an Accessory Mitral Valve

    PubMed Central

    Misumi, Ikuo; Nagao, Asako; Iwamoto, Katsuya; Honda, Tsuyoshi; Ishii, Masanobu; Ueyama, Hidetsugu; Maeda, Yasushi; Ishizaki, Masatoshi; Kurisaki, Ryoichi; Okazaki, Toshio; Yamashita, Tetsuji; Fujimoto, Akiko; Honda, Yumi

    2017-01-01

    A 96-year-old woman developed hemiparesis 2 weeks after orthopedic surgery. Magnetic resonance imaging revealed multiple cerebral infarctions in the bilateral hemisphere. Transthoracic echocardiography revealed a mobile structure attached to the anterior mitral leaflet that protruded toward the left ventricular outflow tract. The structure was identified as an accessory mitral valve. Doppler echocardiography showed that there was no significant left ventricular outflow obstruction. This is a rare case of a silent accessory mitral valve that was detected after multiple cerebral infarctions. PMID:28090044

  1. Reversible cerebral periventricular white matter changes with corpus callosum involvement in acute toluene-poisoning.

    PubMed

    Lin, Chih-Ming; Liu, Chi-Kuang

    2015-01-01

    Substance poisoning, such as toluene intoxication, has seldom been reported in the relevant literature. The documented cerebral neuroimaging has mostly described reversible symmetrical white matter changes in both the cerebral and cerebellar hemispheres. This paper presents 2 patients with toluene poisoning, whose brain magnetic resonance imaging studies showed a similar picture that included extra involvement over the corpus callosum; however, such corpus callosum involvement has never been mentioned and is quite rare in the literature. We discussed the underlying neuropathological pathways in this article. Hopefully, these cases will provide first-line clinicians with some valuable information with regard to toluene intoxication and clinical neuroimaging presentations.

  2. Cerebral infarct with recurrence of hemolytic-uremic syndrome in a child following renal transplantation.

    PubMed

    Mochon, M; Kaiser, B A; deChadarevian, J P; Polinsky, M S; Baluarte, H J

    1992-11-01

    A white girl with a history of atypical hemolytic-uremic syndrome (HUS) and persistent microangiopathic anemia, and thrombocytopenia for 2 months after the initial presentation at age 7 months, received her first cadaveric renal transplant at age 3 years. During the first 2.5 days post transplant, she developed progressive thrombocytopenia and anemia followed by tonic-clonic seizures and loss of consciousness, secondary to a diffuse cerebral infarction of the left hemisphere. Renal histology showed evidence of glomerular microthrombi and microangiopathy. A large cerebral infarct, previously described in patients during their initial presentation with HUS, presented in our patient as part of the recurrence of the disease post renal transplantation.

  3. Antarctic Role in Northern Hemisphere Glaciation

    NASA Astrophysics Data System (ADS)

    Woodard, S. C.; Rosenthal, Y.; Miller, K. G.; Wright, J. D.; Lawrence, K. T.; Chiu, B. K.

    2014-12-01

    The late Pliocene, ~3 million years ago (Ma), is the most recent period in geologic history with elevated atmospheric CO2 and global surface temperature estimates analogous to those projected for the end of the 21st century making it a focus of paleoclimate research. Proxy reconstructions suggest average global sea surface temperatures (SSTs) were ~2-3°C above present during the late Pliocene warm period (~3.3-2.9 Ma). In the North Atlantic, regional SST anomalies reached as much as +6°C and even larger temperature anomalies occurred on land in the northern hemisphere. An episode of global cooling and sea level fall following the warm late Pliocene is attributed to a major expansion of northern hemisphere ice sheets at ~2.73 Ma and referred to as the intensification of northern hemisphere glaciation (NHG). We reconstruct the thermal and geochemical history of North Pacific deep water (ODP Site 1208) from 3.3-2.5 Ma at orbital scale resolution using benthic foraminiferal Mg/Ca and stable isotopic ratios (δ18O, δ13C) in order to evaluate changes in continental ice volume and deep ocean circulation as the climate deteriorated and NHG intensified. We find that the oceanic cooling trend which followed late Pliocene warmth did not occur in the deep Pacific Ocean and an average ~21±10 m sea level equivalent ice growth occurred from 3.15-2.75 Ma prior to the intensification of NHG. Furthermore, both the benthic d18Oc and BWTs in the Pacific are offset from the North Atlantic prior to 2.75 Ma. By ~2.73 Ma (interglacial-glacial cycle G7-G6), the Atlantic-Pacific BWT and d18O gradients were reduced to <1°C and <0.1‰, respectively. We interpret these abrupt hydrographic changes as the initiation of stronger heat and salt transfer from the North Atlantic to the Pacific due to a fundamental change in deep ocean circulation driven by late Pliocene ice growth on Antarctica.

  4. Extended Use of Hypothermia in Elderly Patients with Malignant Cerebral Edema as an Alternative to Hemicraniectomy

    PubMed Central

    Jeong, Han-Yeong; Chang, Jun-Young; Yum, Kyu Sun; Hong, Jeong-Ho; Jeong, Jin-Heon; Yeo, Min-Ju; Bae, Hee-Joon; Han, Moon-Ku; Lee, Kiwon

    2016-01-01

    Background and Purpose The use of decompressive hemicraniectomy (DHC) for the treatment of malignant cerebral edema can decrease mortality rates. However, this benefit is not sufficient to justify its use in elderly patients. We investigated the effects of therapeutic hypothermia (TH) on safety, feasibility, and functional outcomes in elderly patients with malignant middle cerebral artery (MCA) infarcts. Methods Elderly patients 60 years of age and older with infarcts affecting more than two-thirds of the MCA territory were included. Patients who could not receive DHC were treated with TH. Hypothermia was started within 72 hours of symptom onset and was maintained for a minimum of 72 hours with a target temperature of 33°C. Modified Rankin Scale (mRS) scores at 3 months following treatment and complications of TH were used as functional outcomes. Results Eleven patients with a median age of 76 years and a median National Institutes of Health Stroke Scale score of 18 were treated with TH. The median time from symptom onset to initiation of TH was 30.3±23.0 hours and TH was maintained for a median of 76.7±57.1 hours. Shivering (100%) and electrolyte imbalance (82%) were frequent complications. Two patients died (18%). The mean mRS score 3 months following treatment was 4.9±0.8. Conclusions Our results suggest that extended use of hypothermia is safe and feasible for elderly patients with large hemispheric infarctions. Hypothermia may be considered as a therapeutic alternative to DHC in elderly individuals. Further studies are required to validate our findings. PMID:27488978

  5. Brain activity underlying tool-related and imitative skills after major left hemisphere stroke.

    PubMed

    Martin, Markus; Nitschke, Kai; Beume, Lena; Dressing, Andrea; Bühler, Laura E; Ludwig, Vera M; Mader, Irina; Rijntjes, Michel; Kaller, Christoph P; Weiller, Cornelius

    2016-05-01

    Apraxia is a debilitating cognitive motor disorder that frequently occurs after left hemisphere stroke and affects tool-associated and imitative skills. However, the severity of the apraxic deficits varies even across patients with similar lesions. This variability raises the question whether regions outside the left hemisphere network typically associated with cognitive motor tasks in healthy subjects are of additional functional relevance. To investigate this hypothesis, we explored regions where functional magnetic resonance imaging activity is associated with better cognitive motor performance in patients with left hemisphere ischaemic stroke. Thirty-six patients with chronic (>6 months) large left hemisphere infarcts (age ± standard deviation, 60 ± 12 years, 29 male) and 29 control subjects (age ± standard deviation, 72 ± 7, 15 male) were first assessed behaviourally outside the scanner with tests for actual tool use, pantomime and imitation of tool-use gestures, as well as for meaningless gesture imitation. Second, functional magnetic resonance imaging activity was registered during the passive observation of videos showing tool-associated actions. Voxel-wise linear regression analyses were used to identify areas where behavioural performance was correlated with functional magnetic resonance imaging activity. Furthermore, lesions were delineated on the magnetic resonance imaging scans for voxel-based lesion-symptom mapping. The analyses revealed two sets of regions where functional magnetic resonance imaging activity was associated with better performance in the clinical tasks. First, activity in left hemisphere areas thought to mediate cognitive motor functions in healthy individuals (i.e. activity within the putative 'healthy' network) was correlated with better scores. Within this network, tool-associated tasks were mainly related to activity in supramarginal gyrus and ventral premotor cortex, while meaningless gesture imitation depended more on the

  6. Cerebral oxygenation following epinephrine infusion.

    PubMed

    Steinback, Craig D; Zubin, Petra; Breskovic, Toni; Bakovic, Darija; Pivac, Nediljko; Dujic, Zeljko

    2012-10-15

    Evidence suggests that the autonomic nervous system may actively regulate the cerebral vasculature. In this study, central hemodynamics and brain oxy-hemoglobin, deoxy-hemoglobin and total hemoglobin changes (bO₂Hb, bdHb and bTHb) were monitored during infusion of epinephrine (0.06 μg/kg/min over 6 min, and 0.12 μg/kg/min for 3 min) in 12 men. Epinephrine decreased mean arterial pressure (MAP) and total peripheral resistance (TPR), while heart rate (HR), stroke volume (SV) and cardiac output (CO) increased, but did not affect bO₂Hb, bdHb or bTHb. However, upon the cessation of epinephrine infusion an increase in both Oxy- and Total Hb occurred which peaked at 3 min post infusion (+6.0±4.6 and +4.9±4.8 μmol/L respectively, P<0.05) and persisted for 20 min post infusion (+1.5±2.2 and +1.8±2.7 μmol/L respectively, P<0.05). No evidence was found for reduction in cerebral oxygenation during a cold-pressor test. The results of the present study demonstrated that clinical doses of epinephrine result in a delayed increase in cortical blood volume due to an increase in Oxy-Hb, consistent with vasodilation.

  7. Voyager 1 Jupiter Southern Hemisphere Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie shows a portion of Jupiter in the southern hemisphere over 17Jupiter days. Above the white belt, notice the series of atmospheric vortices headed west. Even these early approach frames show wild dynamics in the roiling environment south of the white belt. Notice the small tumbling white cloud near the center.

    As Voyager 1 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 17 images taken once every Jupiter rotation period (about 10 hours). These images were acquired in the Blue filter around Feb. 1, 1979. The spacecraft was about 37 million kilometers from Jupiter at that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  8. Atmospheric Motion in Jupiter's Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    2000-01-01

    True-color (left) and false-color (right) mosaics of Jupiter's northern hemisphere between 10 and 50 degrees latitude. Jupiter's atmospheric motions are controlled by alternating eastward and westward bands of air between Jupiter's equator and polar regions. The direction and speed of these bands influences the color and texture of the clouds seen in this mosaic. The high and thin clouds are represented by light blue, deep clouds are reddish, and high and thick clouds are white. A high haze overlying a clear, deep atmosphere is represented by dark purple. This image was taken by NASA's Galileo spacecraft on April 3, 1997 at a distance of 1.4 million kilometers (.86 million miles).

  9. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation: A functional MRI study.

    PubMed

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-08-25

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation.

  10. External carotid artery angioplasty and stenting to augment cerebral perfusion in the setting of subacute symptomatic ipsilateral internal carotid artery occlusion. Case report.

    PubMed

    Adel, Joseph G; Bendok, Bernard R; Hage, Ziad A; Naidech, Andrew M; Miller, Jeffery W; Batjer, H Hunt

    2007-12-01

    The authors performed external carotid artery (ECA) angioplasty and stenting in a 45-year-old man who had presented with right hemispheric crescendo ischemic symptoms stemming from acute right internal carotid artery occlusion (ICAO). This unique application of ECA angioplasty and stenting augmented cerebral perfusion and improved clinical symptoms. In certain situations, ECA stenting can increase cerebral perfusion in the setting of ICAO and ECA stenosis. The authors are the first to describe this approach in this context.

  11. Hemispherical anomaly from asymmetric initial states

    NASA Astrophysics Data System (ADS)

    Ashoorioon, Amjad; Koivisto, Tomi

    2016-08-01

    We investigate if the hemispherical asymmetry in the CMB is produced from "asymmetric" excited initial conditions. We show that in the limit where the deviations from the Bunch-Davies vacuum are large and the scale of new physics is maximally separated from the inflationary Hubble parameter, the primordial power spectrum is modulated only by position-dependent dipole and quadrupole terms. Requiring the dipole contribution in the power spectrum to account for the observed power asymmetry, A =0.07 ±0.022 , we show that the amount of quadrupole terms is roughly equal to A2. The mean local bispectrum, which gets enhanced for the excited initial state, is within the 1 σ bound of Planck 2015 results for a large field model, fNL≃4.17 , but is reachable by future CMB experiments. The amplitude of the local non-Gaussianity modulates around this mean value, depending on the angle that the correlated patches on the 2d CMB surface make with the preferred direction. The amount of variation is minimized for the configuration in which the short and long wavelength modes are around the preferred pole and |k→3|≈|k→l ≈10|≪|k→1|≈|k→2|≈|k→l ≈2500| with fNLmin≈3.64 . The maximum occurs when these modes are at the antipode of the preferred pole, fNLmax≈4.81 . The difference of non-Gaussianity between these two configurations is as large as ≃1.17 , which can be used to distinguish this scenario from other scenarios that try to explain the observed hemispherical asymmetry.

  12. The Tropical Western Hemisphere Warm Pool

    NASA Astrophysics Data System (ADS)

    Wang, C.; Enfield, D. B.

    2002-12-01

    The paper describes and examines variability of the tropical Western Hemisphere warm pool (WHWP) of water warmer than 28.5oC. The WHWP is the second-largest tropical warm pool on Earth. Unlike the Eastern Hemisphere warm pool in the western Pacific, which straddles the equator, the WHWP is entirely north of the equator. At various stages of development the WHWP extends over parts of the eastern North Pacific, the Gulf of Mexico, the Caribbean, and the western tropical North Atlantic. It has a large seasonal cycle and its interannual fluctuations of area and intensity are significant. Surface heat fluxes warm the WHWP through the boreal spring to an annual maximum of SST and WHWP area in the late summer/early fall, associated with eastern North Pacific and Atlantic hurricane activities and rainfall from northern South America to the southern tier of the United States. Observations suggest that a positive ocean-atmosphere feedback operating through longwave radiation and associated cloudiness seems to operate in the WHWP. During winter preceding large warm pool, there is an alteration of the Walker and Hadley circulation cells that serves as a "tropospheric bridge" for transferring Pacific ENSO effects to the Atlantic sector and inducing initial warming of warm pool. Associated with the warm SST anomalies is a decrease in sea level pressure anomalies and an anomalous increase in atmospheric convection and cloudiness. The increase in convective activity and cloudiness results in less net longwave radiation loss from the sea surface, which then reinforces SST anomalies.

  13. Hypernatraemia in cerebral disorders

    PubMed Central

    Taylor, W. H.

    1962-01-01

    Six patients are described in whom cerebral damage was associated with raised plasma sodium and chloride concentrations and with extremely low urinary outputs of sodium and chloride. The patients were not clinically dehydrated and direct determinations showed that the blood and plasma volumes, the endogenous creatinine clearance, and the urinary output of antidiuretic hormone were normal. For these and other reasons it is concluded that the metabolic picture results not from diminished circulatory volume, water deficiency, sodium deficiency, undetected diabetes insipidus or osmotic diuresis, but from the cerebral damage itself. In these and other cited cases, the cerebral damage was localized chiefly in the frontal lobes, hypothalamus or lower brain-stem, thus suggesting a descending pathway, the relationship of which to the pineal area controlling aldosterone secretion requires clarification. Images PMID:13920001

  14. Duplicated middle cerebral artery.

    PubMed

    Perez, Jesus; Machado, Calixto; Scherle, Claudio; Hierro, Daniel

    2009-01-01

    Duplicated middle cerebral artery (DMCA) is an anomalous vessel arising from the internal carotid artery. The incidence DMCA is relatively law, and an association between this anomaly and cerebral aneurysms has been documented. There is a controversy whether DMCA may have perforating arteries. This is an important fact to consider in aneurysm surgery. We report the case of a 34-year-old black woman who suffered a subarachnoid hemorrhage and the angiography a left DMCA, and an aneurysm in an inferior branch of the main MCA. The DMCA and the MCA had perforating arteries. The aneurysm was clipped without complications. The observation of perforating arteries in our patient confirms that the DMCA may have perforating arteries. This is very important to be considered in cerebral aneurysms surgery. Moreover, the DMCA may potentially serve as a collateral blood supply to the MCA territory in cases of MCA occlusion.

  15. [Cerebral ischemia and histamine].

    PubMed

    Adachi, Naoto

    2002-10-01

    Cerebral ischemia induces excess release of glutamate and an increase in the intracellular Ca2+ concentration, which provoke catastrophic enzymatic processes leading to irreversible neuronal injury. Histamine plays the role of neurotransmitter in the central nervous system, and histaminergic fibers are widely distributed in the brain. In cerebral ischemia, release of histamine from nerve endings has been shown to be enhanced by facilitation of its activity. An inhibition of the histaminergic activity in ischemia aggravates the histologic outcome. In contrast, intracerebroventricular administration of histamine improves the aggravation, whereas blockade of histamine H2 receptors aggravates ischemic injury. Furthermore, H2 blockade enhances ischemic release of glutamate and dopamine. These findings suggest that central histamine provides beneficial effects against ischemic neuronal damage by suppressing release of excitatory neurotransmitters. However, histaminergic H2 action facilitates the permeability of the blood-brain barrier and shows deleterious effects on cerebral edema.

  16. Universal time variations of the auroral hemispheric power and their interhemispheric asymmetry from TIMED/GUVI observations

    NASA Astrophysics Data System (ADS)

    Luan, Xiaoli; Wang, Wenbin; Burns, Alan; Dou, Xiankang

    2016-10-01

    This paper quantitatively analyzes the auroral hemispheric power (HP) and its interhemispheric asymmetry as a function of universal time (UT) for geomagnetically quiet conditions (Kp 1-3) from Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Global Ultraviolet Imager (TIMED/GUVI) imaging observations. The HP variation with UT can be approximately characterized as two cases: One is for similar HP variations in the equinoxes in the Northern Hemisphere and for the June solstices of both hemispheres, and the other is for similar HP patterns in the equinoxes in the Southern Hemisphere and for the December solstices of both hemispheres. In the equinoxes, the HP variations are interhemispherically asymmetric due to different occurrence time of the HP peak. In the solstices, the HP is generally interhemispherically symmetric in its diurnal variations, but there is interhemispheric asymmetry in the magnitudes of the maximum HP. For geomagnetically quiet conditions (Kp = 2), in the equinoxes relative interhemispheric differences are typically between 0 and 20%, with respect to the averaged HP from the two hemispheres, while during the solstices, the maximum relative interhemispheric asymmetry can be as large as 30% in December, but it is only 15% in June. These two cases are mainly associated with variations of auroral precipitation power in the night side sector (21:00-03:00 magnetic local time/MLT), which are primarily controlled by solar illumination conditions in both hemispheres and are also attributed to the difference in the geographical area of the auroral oval in the two hemispheres. Furthermore, the general interhemispheric symmetry of the HP variations in solstices suggests that auroral acceleration is not only controlled locally by solar illumination conditions, which has been well known previously, but also might be affected by processes in the precipitation source region.

  17. Impaired cerebral autoregulation in obstructive sleep apnea.

    PubMed

    Urbano, Fred; Roux, Francoise; Schindler, Joseph; Mohsenin, Vahid

    2008-12-01

    Obstructive sleep apnea (OSA) increases the risk of stroke independent of known vascular and metabolic risk factors. Although patients with OSA have higher prevalence of hypertension and evidence of hypercoagulability, the mechanism of this increased risk is unknown. Obstructive apnea events are associated with surges in blood pressure, hypercapnia, and fluctuations in cerebral blood flow. These perturbations can adversely affect the cerebral circulation. We hypothesized that patients with OSA have impaired cerebral autoregulation, which may contribute to the increased risk of cerebral ischemia and stroke. We examined cerebral autoregulation in patients with and without OSA by measuring cerebral artery blood flow velocity (CBFV) by using transcranial Doppler ultrasound and arterial blood pressure using finger pulse photoplethysmography during orthostatic hypotension and recovery as well as during 5% CO(2) inhalation. Cerebral vascular conductance and reactivity were determined. Forty-eight subjects, 26 controls (age 41.0+/-2.3 yr) and 22 OSA (age 46.8+/-2.3 yr) free of cerebrovascular and active coronary artery disease participated in this study. OSA patients had a mean apnea-hypopnea index of 78.4+/-7.1 vs. 1.8+/-0.3 events/h in controls. The oxygen saturation during sleep was significantly lower in the OSA group (78+/-2%) vs. 91+/-1% in controls. The dynamic vascular analysis showed mean CBFV was significantly lower in OSA patients compared with controls (48+/-3 vs. 55+/-2 cm/s; P <0.05, respectively). The OSA group had a lower rate of recovery of cerebrovascular conductance for a given drop in blood pressure compared with controls (0.06+/-0.02 vs. 0.20+/-0.06 cm.s(-2).mmHg(-1); P <0.05). There was no difference in cerebrovascular vasodilatation in response to CO(2). The findings showed that patients with OSA have decreased CBFV at baseline and delayed cerebrovascular compensatory response to changes in blood pressure but not to CO(2). These perturbations may

  18. Relative hand skill predicts academic ability: global deficits at the point of hemispheric indecision.

    PubMed

    Crow, T J; Crow, L R; Done, D J; Leask, S

    1998-12-01

    Population variation in handedness (a correlate of cerebral dominance for language) is in part genetic and, it has been suggested, its persistence represents a balanced polymorphism with respect to cognitive ability. This hypothesis was tested in a sample of 12,770 individuals in a UK national cohort (the National Child Development Study) by assessing relative hand skill (in a square checking task) as a predictor of verbal, non-verbal, and mathematical ability and reading comprehension at the age of 11 years. Whereas some modest decrements were present in extreme right handers the most substantial deficits in ability were seen close to the point of equal hand skill ('hemispheric indecision'). For verbal ability females performed better than males, but the relationship to relative hand skill was closely similar for the two sexes; for reading comprehension males close to the point of equal hand skill showed greater impairments than females. Analysed by writing hand the relationship of ability to hand skill appeared symmetrical about the point of 'hemispheric indecision'. The variation associated with degrees of dominance may reflect the operation of continuing selection on the gene (postulated to be X-Y linked) by which language evolved and speciation occurred.

  19. Right Hemispheric Leukoencephalopathy as an Incidental Finding Following a Lightning Strike

    PubMed Central

    Kruja, Jera; Kuqo, Altin; Grabova, Serla; Rroji, Arben; Vyshka, Gentian

    2016-01-01

    BACKGROUND: Lightning injuries may produce a variety of medical conditions, and specific neurological complications have been identified, with the character of immediate aftershock effects or even long-term consequences. AIM: The authors describe the incidental finding following a routine unenhanced brain MRI performed to a young female patient, suffering from a headache. CASE REPORT: Diffuse white matter changes with the character of a leukoencephalopathy were seen, which strictly interested only the right cerebral hemisphere. The parents referred that she suffered from an indoor lightning strike at age of seven months, although she survived with almost no external burns or signs, and recovered uneventfully at that time. A discussion over the effects of electrocution and lightning strike on the human body in general, and over the nervous system, is made. Particular attention must be shown when making the differential diagnosis of leukoencephalopathies with a strictly one-hemisphere extension since several other conditions might resemble each other under the radiological aspect, here including brain viral infections, genetic disorders, and so on. CONCLUSION: The particularity of the long-term aftershock effects of the lightning strike on the central nervous system raise again the necessity of collecting data and duly reporting every electrical accident, lightning events included. PMID:28028416

  20. Re-assessing acalculia: Distinguishing spatial and purely arithmetical deficits in right-hemisphere damaged patients.

    PubMed

    Benavides-Varela, S; Piva, D; Burgio, F; Passarini, L; Rolma, G; Meneghello, F; Semenza, C

    2017-03-01

    Arithmetical deficits in right-hemisphere damaged patients have been traditionally considered secondary to visuo-spatial impairments, although the exact relationship between the two deficits has rarely been assessed. The present study implemented a voxelwise lesion analysis among 30 right-hemisphere damaged patients and a controlled, matched-sample, cross-sectional analysis with 35 cognitively normal controls regressing three composite cognitive measures on standardized numerical measures. The results showed that patients and controls significantly differ in Number comprehension, Transcoding, and Written operations, particularly subtractions and multiplications. The percentage of patients performing below the cutoffs ranged between 27% and 47% across these tasks. Spatial errors were associated with extensive lesions in fronto-temporo-parietal regions -which frequently lead to neglect- whereas pure arithmetical errors appeared related to more confined lesions in the right angular gyrus and its proximity. Stepwise regression models consistently revealed that spatial errors were primarily predicted by composite measures of visuo-spatial attention/neglect and representational abilities. Conversely, specific errors of arithmetic nature linked to representational abilities only. Crucially, the proportion of arithmetical errors (ranging from 65% to 100% across tasks) was higher than that of spatial ones. These findings thus suggest that unilateral right hemisphere lesions can directly affect core numerical/arithmetical processes, and that right-hemisphere acalculia is not only ascribable to visuo-spatial deficits as traditionally thought.

  1. Cerebral venous sinus thrombosis with cerebral hemorrhage during early pregnancy

    PubMed Central

    Nie, Quanmin; Guo, Pin; Ge, Jianwei; Qiu, Yongming

    2015-01-01

    Cerebral venous sinus thrombosis (CVST) rarely induces cerebral hemorrhage, and CVST with cerebral hemorrhage during early pregnancy is extremely rare. Upon literature review, we are able to find only one case of CVST with cerebral hemorrhage in early pregnancy. In this paper, we report another case of a 27-year-old patient who developed CVST with cerebral hemorrhage in her fifth week of pregnancy. Although the optimal treatment for this infrequent condition remains controversial, we adopted anticoagulation as the first choice of treatment and obtained favorable results. PMID:25630781

  2. Computational Pipeline for NIRS-EEG Joint Imaging of tDCS-Evoked Cerebral Responses—An Application in Ischemic Stroke

    PubMed Central

    Guhathakurta, Debarpan; Dutta, Anirban

    2016-01-01

    Transcranial direct current stimulation (tDCS) modulates cortical neural activity and hemodynamics. Electrophysiological methods (electroencephalography-EEG) measure neural activity while optical methods (near-infrared spectroscopy-NIRS) measure hemodynamics coupled through neurovascular coupling (NVC). Assessment of NVC requires development of NIRS-EEG joint-imaging sensor montages that are sensitive to the tDCS affected brain areas. In this methods paper, we present a software pipeline incorporating freely available software tools that can be used to target vascular territories with tDCS and develop a NIRS-EEG probe for joint imaging of tDCS-evoked responses. We apply this software pipeline to target primarily the outer convexity of the brain territory (superficial divisions) of the middle cerebral artery (MCA). We then present a computational method based on Empirical Mode Decomposition of NIRS and EEG time series into a set of intrinsic mode functions (IMFs), and then perform a cross-correlation analysis on those IMFs from NIRS and EEG signals to model NVC at the lesional and contralesional hemispheres of an ischemic stroke patient. For the contralesional hemisphere, a strong positive correlation between IMFs of regional cerebral hemoglobin oxygen saturation and the log-transformed mean-power time-series of IMFs for EEG with a lag of about −15 s was found after a cumulative 550 s stimulation of anodal tDCS. It is postulated that system identification, for example using a continuous-time autoregressive model, of this coupling relation under tDCS perturbation may provide spatiotemporal discriminatory features for the identification of ischemia. Furthermore, portable NIRS-EEG joint imaging can be incorporated into brain computer interfaces to monitor tDCS-facilitated neurointervention as well as cortical reorganization. PMID:27378836

  3. Lever arm dysfunction in cerebral palsy gait.

    PubMed

    Theologis, Tim

    2013-11-01

    Skeletal structures act as lever arms during walking. Muscle activity and the ground reaction against gravity exert forces on the skeleton, which generate torque (moments) around joints. These lead to the sequence of movements which form normal human gait. Skeletal deformities in cerebral palsy (CP) affect the function of bones as lever arms and compromise gait. Lever arm dysfunction should be carefully considered when contemplating treatment to improve gait in children with CP.

  4. Decreased oxygen saturation in asymmetrically prominent cortical veins in patients with cerebral ischemic stroke.

    PubMed

    Xia, Shuang; Utriainen, David; Tang, Jin; Kou, Zhifeng; Zheng, Gang; Wang, Xuesong; Shen, Wen; Haacke, E Mark; Lu, Guangming

    2014-12-01

    Decreased oxygen saturation in asymmetrically prominent cortical veins (APCV) seen in ischemic stroke has been hypothesized to correlate with an increase of de-oxygenated hemoglobin. Our goal is to quantify magnetic susceptibility to define APCV by establishing a cutoff above which the deoxyhemoglobin levels are considered abnormal. A retrospective study was conducted on 26 patients with acute ischemic stroke in one cerebral hemisphere that exhibited APCV with 30 age- and sex-matched healthy controls. Quantitative susceptibility mapping (QSM) was used to calculate the magnetic susceptibility of the cortical veins. A paired t-test was used to compare the susceptibility of the cortical veins in the left and right hemispheres for healthy controls as well as in the contralateral hemisphere for stroke patients with APCV. The change in oxygen saturation in the APCV relative to the contralateral side was calculated after thresholding the susceptibility using the mean plus two standard deviations of the contralateral side for each individual. The thresholded susceptibility value of the APCVs in the stroke hemisphere was 254±48 ppb which was significantly higher (p<0.05) than that in the contralateral hemisphere (123±12 ppb) and in healthy controls (125±8 ppb). There was a decrease of oxygen saturation in the APCV ranging from 16% to 44% relative to the veins of the contralateral hemisphere. In conclusion, APCV seen in SWI correspond to reduced levels of oxygen saturation and these abnormal veins can be identified using a susceptibility threshold on the QSM data.

  5. State anxiety reduction and exercise: does hemispheric activation reflect such changes?

    PubMed

    Petruzzello, S J; Landers, D M

    1994-08-01

    Acute bouts of aerobic exercise have been consistently associated with significant reductions in anxiety, but explanations for this effect remain elusive. The cerebral lateralization hypothesis predicts that anxiety reductions would be caused by a postexercise decrease in anterior right, relative to left, hemisphere activation. A sample of 19 right-handed males ran at 75% of their VO2max for 30 min on a treadmill. Electroencephalogram (EEG; F3, F4, T3, T4) and state anxiety were collected before and following exercise. Compared with preexercise, anxiety was significantly (P < 0.05) reduced at 10, 20, and 30 min postexercise. Preexercise EEG alpha asymmetry was significantly related to trait anxiety and also predicted a significant amount of variance (30%; P = 0.008) in postexercise anxiety reduction. From pre- to postexercise, the relative activation of the left frontal area increased with respect to the homologous right frontal site. Within-subject correlations for the change in anxiety with corresponding EEG changes were small but in line with theoretical predictions. It is concluded that the cerebral lateralization hypothesis remains tenable for explaining anxiety reductions associated with exercise.

  6. ERP Evidence of Hemispheric Independence in Visual Word Recognition

    ERIC Educational Resources Information Center

    Nemrodov, Dan; Harpaz, Yuval; Javitt, Daniel C.; Lavidor, Michal

    2011-01-01

    This study examined the capability of the left hemisphere (LH) and the right hemisphere (RH) to perform a visual recognition task independently as formulated by the Direct Access Model (Fernandino, Iacoboni, & Zaidel, 2007). Healthy native Hebrew speakers were asked to categorize nouns and non-words (created from nouns by transposing two middle…

  7. Hemispheric Differences in the Effects of Context on Vowel Perception

    ERIC Educational Resources Information Center

    Sjerps, Matthias J.; Mitterer, Holger; McQueen, James M.

    2012-01-01

    Listeners perceive speech sounds relative to context. Contextual influences might differ over hemispheres if different types of auditory processing are lateralized. Hemispheric differences in contextual influences on vowel perception were investigated by presenting speech targets and both speech and non-speech contexts to listeners' right or left…

  8. Hemispheric Differences in the Organization of Memory for Text Ideas

    ERIC Educational Resources Information Center

    Long, Debra L.; Johns, Clinton L.; Jonathan, Eunike

    2012-01-01

    The goal of this study was to examine hemispheric asymmetries in episodic memory for discourse. Access to previously comprehended information is essential for mapping incoming information to representations of "who did what to whom" in memory. An item-priming-in-recognition paradigm was used to examine differences in how the hemispheres represent…

  9. Divergent hemispheric reasoning strategies: reducing uncertainty versus resolving inconsistency.

    PubMed

    Marinsek, Nicole; Turner, Benjamin O; Gazzaniga, Michael; Miller, Michael B

    2014-01-01

    Converging lines of evidence from diverse research domains suggest that the left and right hemispheres play distinct, yet complementary, roles in inferential reasoning. Here, we review research on split-brain patients, brain-damaged patients, delusional patients, and healthy individuals that suggests that the left hemisphere tends to create explanations, make inferences, and bridge gaps in information, while the right hemisphere tends to detect conflict, update beliefs, support mental set-shifts, and monitor and inhibit behavior. Based on this evidence, we propose that the left hemisphere specializes in creating hypotheses and representing causality, while the right hemisphere specializes in evaluating hypotheses, and rejecting those that are implausible or inconsistent with other evidence. In sum, we suggest that, in the domain of inferential reasoning, the left hemisphere strives to reduce uncertainty while the right hemisphere strives to resolve inconsistency. The hemispheres' divergent inferential reasoning strategies may contribute to flexible, complex reasoning in the healthy brain, and disruption in these systems may explain reasoning deficits in the unhealthy brain.

  10. Disentangling the Relationship between Hemispheric Asymmetry and Cognitive Performance

    ERIC Educational Resources Information Center

    Hirnstein, Marco; Leask, Stuart; Rose, Jonas; Hausmann, Markus

    2010-01-01

    It is widely believed that advantages of hemispheric asymmetries originated in better cognitive processing, hence it is often implied that the relationship between hemispheric asymmetry and cognitive performance is linearly positive: the higher the degree of lateralization in a specific cognitive domain, the better the performance in a…

  11. Hemispheric Asymmetry in the Efficiency of Attentional Networks

    ERIC Educational Resources Information Center

    Asanowicz, Dariusz; Marzecova, Anna; Jaskowski, Piotr; Wolski, Piotr

    2012-01-01

    Despite the fact that hemispheric asymmetry of attention has been widely studied, a clear picture of this complex phenomenon is still lacking. The aim of the present study was to provide an efficient and reliable measurement of potential hemispheric asymmetries of three attentional networks, i.e. alerting, orienting and executive attention.…

  12. Stroke from Vasospasm due to Marijuana Use: Can Cannabis Synergistically with Other Medications Trigger Cerebral Vasospasm?

    PubMed

    Jamil, Marium; Zafar, Atif; Adeel Faizi, Syed; Zawar, Ifrah

    2016-01-01

    We present a case of imaging proven cerebral vasospasm causing ischemic stroke in a young patient chronically on buprenorphine-naloxone for heroin remission who started smoking cannabis on a daily basis. With cannabis legalization spreading across the states in the USA, it is important for physicians not only to be aware of cannabis reported association with cerebral vasospasm in some patients but also to be on the lookout for possible interacting medications that can synergistically affect cerebral vessels causing debilitating strokes.

  13. [Clinico-epidemiological characteristics of transient cerebral ischemia in the region of the Ukrainian Carpathian Mountains].

    PubMed

    Buletsa, B A; Lupich, P P; Litvinova, L A

    1991-01-01

    Altogether 225 patients with transitory derangements of cerebral circulation (TDCC) underwent clinico-laboratory examinations. Arterial hypertension and cerebral atherosclerosis turned out to be among most frequently occurring factors of TDCC. The provoking factors included psychoemotional stress and drops of barometric pressure. The course and outcome of TDCC were greatly affected by an increase in blood concentration of catecholamines and thyroid hormones. The high concentration of triiodothyronine in the blood contributed to the development of cerebral stroke.

  14. Transcranial laser stimulation improves human cerebral oxygenation

    PubMed Central

    Tian, Fenghua; Hase, Snehal N.

    2016-01-01

    Background and Objective Transcranial laser stimulation of the brain with near‐infrared light is a novel form of non‐invasive photobiomodulation or low‐level laser therapy (LLLT) that has shown therapeutic potential in a variety of neurological and psychological conditions. Understanding of its neurophysiological effects is essential for mechanistic study and treatment evaluation. This study investigated how transcranial laser stimulation influences cerebral hemodynamics and oxygenation in the human brain in vivo using functional near‐infrared spectroscopy (fNIRS). Materials and Methods Two separate experiments were conducted in which 1,064‐nm laser stimulation was administered at (1) the center and (2) the right side of the forehead, respectively. The laser emitted at a power of 3.4 W and in an area of 13.6 cm2, corresponding to 0.25 W/cm2 irradiance. Stimulation duration was 10 minutes. Nine healthy male and female human participants of any ethnic background, in an age range of 18–40 years old were included in each experiment. Results In both experiments, transcranial laser stimulation induced an increase of oxygenated hemoglobin concentration (Δ[HbO2]) and a decrease of deoxygenated hemoglobin concentration (Δ[Hb]) in both cerebral hemispheres. Improvements in cerebral oxygenation were indicated by a significant increase of differential hemoglobin concentration (Δ[HbD] = Δ[HbO2] − Δ[Hb]). These effects increased in a dose‐dependent manner over time during laser stimulation (10 minutes) and persisted after laser stimulation (6 minutes). The total hemoglobin concentration (Δ[HbT] = Δ[HbO2] + Δ[Hb]) remained nearly unchanged in most cases. Conclusion Near‐infrared laser stimulation applied to the forehead can transcranially improve cerebral oxygenation in healthy humans. Lasers Surg. Med. 48:343–349, 2016. © 2016 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc. PMID:26817446

  15. Cerebral Folate Deficiency

    ERIC Educational Resources Information Center

    Gordon, Neil

    2009-01-01

    Cerebral folate deficiency (CFD) is associated with low levels of 5-methyltetrahydrofolate in the cerebrospinal fluid (CSF) with normal folate levels in the plasma and red blood cells. The onset of symptoms caused by the deficiency of folates in the brain is at around 4 to 6 months of age. This is followed by delayed development, with deceleration…

  16. United Cerebral Palsy

    MedlinePlus

    ... be sure to follow us on Twitter ! Affiliate Network UCP affiliates provide services and support on a community-by-community basis, serving the unique needs of people with disabilities in their region. Find your ... and their networks. Individuals with cerebral palsy and other disabilities deserve ...

  17. Hemispheric sea ice distribution sets the glacial tempo

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Eun; Shen, Aaron; Fox-Kemper, Baylor; Ming, Yi

    2017-01-01

    The proxy record of global temperature shows that the dominant periodicity of the glacial cycle shifts from 40 kyr (obliquity) to 100 kyr (eccentricity) about a million years ago. Using climate model simulations, here we show that the pace of the glacial cycle depends on the pattern of hemispheric sea ice growth. In a cold climate the sea ice grows asymmetrically between two hemispheres under changes to Earth's orbital precession, because sea ice growth potential outside of the Arctic Circle is limited. This difference in hemispheric sea ice growth leads to an asymmetry in absorbed solar energy for the two hemispheres, particularly when eccentricity is high, even if the annual average insolation is similar. In a warmer climate, the hemispheric asymmetry of the sea ice decreases as mean Arctic and Antarctic sea ice decreases, diminishing the precession and eccentricity signals and explaining the dominant obliquity signal (40 kyr) before the mid-Pleistocene transition.

  18. Atmospheric Blocking in the Northern Hemisphere.

    NASA Astrophysics Data System (ADS)

    Knox, John Lewis

    Blocking is generally understood as the obstruction on a large scale of the normal west - to - east motion of mid-latitude pressure systems. It is a persistent phenomenon lasting from one to several weeks and the resulting prolonged weather regimes may have serious economic and social consequences. The recent Northern Hemisphere winters, starting with 1976 -77, featured unusually large circulation anomalies, many of which can be directly related to prolonged episodes of large scale blocking. The intent of this study is to investigate the statistics and certain diagnostics of blocking in the Northern Hemisphere. The first of the three primary objectives is to present and interpret the spatial and temporal distribution of blocking during the past 33 years. We develop objective identification criteria, adaptable to machine processing methods, by relating the blocking anticyclone to its associated positive anomaly of 5-day mean 500MB height. Anomalies meeting the criteria are called 'blocking signatures.' We present the seasonal frequency of occurrence of these signatures by longitude and by area. The results are in good agreement with published studies for the oceans, but they also reveal a high frequency of blocking signatures over the Northeastern Canadian Archipelago. This result, dubbed the 'Baffin Island Paradox' is further investigated and rationalized. A catalogue has been prepared which identifies the date, centre location and magnitude of every blocking signature which occurred from January 1, 1946 to December 31, 1978. A supplementary Catalogue identifies sequences of these signatures corresponding to actual blocking episodes. The second objective is to investigate whether regions with high incidence of blocking, in either the developing or the mature stage, features non-Gaussian distributions of 5-day mean geopotential. During winter, fields of significantly low kurtosis are found in certain mid-latitude regions where the genesis and amplification of

  19. Seismic hazard map of the western hemisphere

    USGS Publications Warehouse

    Shedlock, K.M.; Tanner, J.G.

    1999-01-01

    Vulnerability to natural disasters increases with urbanization and development of associated support systems (reservoirs, power plants, etc.). Catastrophic earthquakes account for 60% of worldwide casualties associated with natural disasters. Economic damage from earthquakes is increasing, even in technologically advanced countries with some level of seismic zonation, as shown by the 1989 Loma Prieta, CA ($6 billion), 1994 Northridge, CA ($ 25 billion), and 1995 Kobe, Japan (> $ 100 billion) earthquakes. The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures, due to an insufficient knowledge of existing seismic hazard. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. National, state, and local governments, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require seismic hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes), emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The seismic hazard map of the Americas is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful global seismic hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This seismic hazard map depicts Peak Ground Acceleration (PGA) with a 10% chance of exceedance in 50 years for the western hemisphere. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include seismic provisions specify the

  20. Detailed Cloud Patterns in Martian Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Cold and cloudy mornings; cool, hazy afternoons. High winds aloft and weather fronts moving slowly to the east. It is winter in the Martian northern hemisphere. One of the many reasons to study Mars is that, at times, its weather is very 'Earth-like.' At this time of the Martian year, clouds are abundant, especially in the morning and especially in the high northern latitudes. Clouds and fogs are also observed in low-lying areas farther to the south, in some lowlands they are as far south as the equator.

    The above color composite images, obtained by Mars Global Surveyor's camera on June 4, 1998, illustrate this Martian 'weather report.' Most of the thick, white clouds seen here occur north of latitude 35oN (roughly equivalent to Albuquerque NM, Memphis TN, and Charlotte, NC). Fog (seen as bright orange because it is lighter than the ground but some of the ground is still visible) occupies the lowest portions of the Kasei Valles outflow channel around 30oN and at 25oN.

    Several different types of cloud features are seen. The repetitious, wash-board pattern of parallel lines are 'gravity wave clouds'. These commonly form, in the lee--downwind side-- of topographic features such as mountain ranges (on Earth) or crater rims (on Mars), under very specific atmospheric conditions (low temperatures, high humidity, and high wind speeds). In this area, the wave clouds are lower in the atmosphere than some of the other clouds. These other clouds show attributes reflecting more the regional weather pattern, occasionally showing the characteristic 'slash' shape (southwest to northeast) of a weather front. These clouds probably contain mostly crystals of water ice but, depending on the temperature at high altitude (and more likely closer to the pole), some could also contain frozen carbon dioxide ('dry ice').

    MOC images 34501 (the red wide angle image) and 34502 (the blue wide angle image) were obtained on Mars Global Surveyor's 345th orbit about the planet