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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. Cerebral Hemispheric Lateralization Associated with Hippocampal Sclerosis May Affect Interictal Cardiovascular Autonomic Functions in Temporal Lobe Epilepsy

    PubMed Central

    Ghchime, Rokia; Benjelloun, Halima; Kiai, Hajar; Belaidi, Halima; Lahjouji, Fatiha; Ouazzani, Reda

    2016-01-01

    It is well established that the temporal lobe epilepsy (TLE) is linked to the autonomic nervous system dysfunctions. Seizures alter the function of different systems such as the respiratory, cardiovascular, gastrointestinal, and urogenital systems. The aim of this work was to evaluate the possible factors which may be involved in interictal cardiovascular autonomic function in temporal lobe epilepsy with complex partial seizures, and with particular attention to hippocampal sclerosis. The study was conducted in 30 patients with intractable temporal lobe epilepsy (19 with left hippocampal sclerosis, 11 with right hippocampal sclerosis). All subjects underwent four tests of cardiac autonomic function: heart rate changes in response to deep breathing, heart rate, and blood pressure variations throughout resting activity and during hand grip, mental stress, and orthostatic tests. Our results show that the right cerebral hemisphere predominantly modulates sympathetic activity, while the left cerebral hemisphere mainly modulates parasympathetic activity, which mediated tachycardia and excessive bradycardia counterregulation, both of which might be involved as a mechanism of sudden unexpected death in epilepsy patients (SUDEP). PMID:27006827

  3. The cerebral hemispheres and bilateral neural nets.

    PubMed

    Cook, N D; Beech, A R

    1990-06-01

    A high-level cognitive dichotomy ("language and context") is reviewed in relation to empirical findings concerning the functions of the human cerebral hemispheres. We argue that the right hemisphere's involvement in the generation of connotative and contextual information in parallel with the denotative and literal language functions of the left hemisphere provides an important insight into the organization of viable cognitive systems. The role of the corpus callosum in producing the dichotomy is discussed. Finally, the generation of asymmetrical activity in structurally symmetrical, bilateral neural nets is described. The model demonstrates how complementary memory states can be generated in bilateral nets without assuming different modes of information processing, provided that the nets have inhibitory, homotopic connections. Unlike excitatory connections, inhibitory connections are sufficient to generate asymmetric hemispheric activity without postulating intrinsic differences between the cerebral hemispheres.

  4. Reciprocal organization of the cerebral hemispheres

    PubMed Central

    McGilchrist, Iain

    2010-01-01

    The cerebral hemispheres are anatomically and neurophysiologically asymmetrical. The evolutionary basis for these differences remains uncertain. There are, however, highly consistent differences between the hemispheres, evident in reptiles, birds, and mammals, as well as in humans, in the nature of the attention each applies to the environment. This permits the simultaneous application of precisely focused, but narrow, attention, needed for grasping food or prey, with broad, open, and uncommitted attention, needed to watch out for predators and to interpret the intentions of conspecifics. These different modes of attention can account for a very wide range of repeated observations relating to hemisphere specialization, and suggest that hemisphere differences lie not in discrete functional domains as such, but distinct modes of functioning within any one domain. These modes of attention are mutually incompatible, and their application depends on inhibitory transmission in the corpus callosum. There is also an asymmetry of interaction between the hemispheres at the phenomenological level. PMID:21319495

  5. 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. PMID:21528369

  6. 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…

  7. Cerebral hemispheric asymmetries in processing lexical metaphors.

    PubMed

    Anaki, D; Faust, M; Kravetz, S

    1998-04-01

    This study investigated semantic priming for literal (stinging-mosquito) and metaphoric (stinging-insult) associates presented to either the left or right visual fields (RVF/LVF) across stimulus-onset-asynchronies (SOA) of 200 and 800 ms. For the short SOA condition, facilitation was found for metaphorically related targets in both visual fields (VFs) while literally related targets were facilitated only in the RVF. For the long SOA condition, metaphorically related targets were facilitated in the LVF whereas literally related targets were facilitated in the RVF. These results support previous findings indicating an enhanced role of the RH in metaphoric comprehension. In addition, the present results are in accordance with current models of hemispheric semantic processing.

  8. Cerebral melioidosis for the first time in the western hemisphere

    PubMed Central

    Vestal, Matthew L.; Wong, Emily B.; Milner, Dan A.; Gormley, William B.; Dunn, Ian F.

    2015-01-01

    This report is the first published case of cerebral melioidosis in the western hemisphere. In this paper the authors review the literature on neurological melioidosis and its presentation and treatment in endemic areas, describe the clinical course of this unique case of a presentation of the disease with cranial abscess in the US, review the pathological and radiological findings associated with this seminal case, and put forth recommendations for recognizing and treating possible future instances of the disease within the western hemisphere. PMID:23767895

  9. 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…

  10. 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.

  11. 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.

  12. Carotid endarterectomy, siphon stenosis, collateral hemispheric pressure, and perioperative cerebral infarction.

    PubMed

    Lord, R S; Raj, T B; Graham, A R

    1987-10-01

    To determine whether moderate stenosis (50% to 80%) of the intracranial segment of the internal carotid artery increases the risk of cerebral infarction after carotid endarterectomy, the arteriograms, ocular pneumoplethysmograms, internal carotid back pressure, and clinical outcome after 169 operations were reviewed. Siphon stenoses less than 50% were not included because of their doubtful anatomic and hemodynamic significance. No patients with stenosis greater than 80% underwent operation. Moderate siphon stenosis affected 37 vessels, 24 (14.2%) ipsilateral and 13 (7.6%) contralateral to the side of operation. Eight patients had bilateral siphon stenosis. Three patients had stroke after operation; none of these cases had siphon stenosis. Moderate siphon stenosis did not increase the risk of perioperative cerebral infarction. Stroke only occurred in those patients in whom there was arteriographic or functional evidence that the affected hemisphere was isolated from effective collateral vessels.

  13. Protein nitration impairs the myogenic tone of rat middle cerebral arteries in both ischemic and nonischemic hemispheres after ischemic stroke.

    PubMed

    Coucha, Maha; Li, Weiguo; Johnson, Maribeth H; Fagan, Susan C; Ergul, Adviye

    2013-12-01

    The myogenic response is crucial for maintaining vascular resistance to achieve constant perfusion during pressure fluctuations. Reduced cerebral blood flow has been reported in ischemic and nonischemic hemispheres after stroke. Ischemia-reperfusion injury and the resulting oxidative stress impair myogenic responses in the ischemic hemisphere. Yet, the mechanism by which ischemia-reperfusion affects the nonischemic side is still undetermined. The goal of the present study was to determine the effect of ischemia-reperfusion injury on the myogenic reactivity of cerebral vessels from both hemispheres and whether protein nitration due to excess peroxynitrite production is the underlying mechanism of loss of tone. Male Wistar rats were subjected to sham operation or 30-min middle cerebral artery occlusion/45-min reperfusion. Rats were administered saline, the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III), or the nitration inhibitor epicatechin at reperfusion. Middle cerebral arteries isolated from another set of control rats were exposed to ex vivo oxygen-glucose deprivation with and without glycoprotein 91 tat (NADPH oxidase inhibitor) or N(ω)-nitro-l-arginine methyl ester. Myogenic tone and nitrotyrosine levels were determined. Ischemia-reperfusion injury impaired the myogenic tone of vessels in both hemispheres compared with the sham group (P < 0.001). Vessels exposed to ex vivo oxygen-glucose deprivation experienced a similar loss of myogenic tone. Inhibition of peroxynitrite parent radicals significantly improved the myogenic tone. Peroxynitrite scavenging or inhibition of nitration improved the myogenic tone of vessels from ischemic (P < 0.001 and P < 0.05, respectively) and nonischemic (P < 0.01 and P < 0.05, respectively) hemispheres. Nitration was significantly increased in both hemispheres versus the sham group and was normalized with epicatechin treatment. In conclusion, ischemia-reperfusion injury impairs

  14. 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)

  15. Semantic Processing of Living and Nonliving Concepts across the Cerebral Hemispheres

    ERIC Educational Resources Information Center

    Pilgrim, L.K.; Moss, H.E.; Tyler, L.K.

    2005-01-01

    Studies of patients with category-specific semantic deficits suggest that the right and left cerebral hemispheres may be differently involved in the processing of living and nonliving domains concepts. In this study, we investigate whether there are hemisphere differences in the semantic processing of these domains in healthy volunteers. Based on…

  16. 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

  17. Category Membership and Semantic Coding in the Cerebral Hemispheres.

    PubMed

    Turner, Casey E; Kellogg, Ronald T

    2016-01-01

    Although a gradient of category membership seems to form the internal structure of semantic categories, it is unclear whether the 2 hemispheres of the brain differ in terms of this gradient. The 2 experiments reported here examined this empirical question and explored alternative theoretical interpretations. Participants viewed category names centrally and determined whether a closely related or distantly related word presented to either the left visual field/right hemisphere (LVF/RH) or the right visual field/left hemisphere (RVF/LH) was a member of the category. Distantly related words were categorized more slowly in the LVF/RH relative to the RVF/LH, with no difference for words close to the prototype. The finding resolved past mixed results showing an unambiguous typicality effect for both visual field presentations. Furthermore, we examined items near the fuzzy border that were sometimes rejected as nonmembers of the category and found both hemispheres use the same category boundary. In Experiment 2, we presented 2 target words to be categorized, with the expectation of augmenting the speed advantage for the RVF/LH if the 2 hemispheres differ structurally. Instead the results showed a weakening of the hemispheric difference, arguing against a structural in favor of a processing explanation. PMID:27424416

  18. Unbiasing the Brain: The Effects of Meditation upon The Cerebral Hemispheres.

    ERIC Educational Resources Information Center

    Meissner, John; Pirot, Michael

    1983-01-01

    Assessed the effects of Transcendental Meditation on the perceptual efficiency of the cerebral hemispheres in 20 right-handed men who underwent reaction time trials to an auditory stimulus. Results suggested Transcedental Meditation is an attentional strategy that disrupts the usual biases of the brain. (JAC)

  19. [Protein metabolism in the cerebral hemispheres during the emotional-algesic stress].

    PubMed

    Yakushev, V S; Davydov, V V; Bushueva, V V; Skurygin, V P; Krisanova, N V

    1985-01-01

    Emotional-algesic stress causes essential changes in the protein metabolism of cerebral hemispheres. These changes may be of great importance for the functioning of the brain and cause the disturbances of the higher nervous activity when the organism is influenced by the emotional stress factors. PMID:4039861

  20. Semantic processing of living and nonliving concepts across the cerebral hemispheres.

    PubMed

    Pilgrim, L K; Moss, H E; Tyler, L K

    2005-07-01

    Studies of patients with category-specific semantic deficits suggest that the right and left cerebral hemispheres may be differently involved in the processing of living and nonliving domains concepts. In this study, we investigate whether there are hemisphere differences in the semantic processing of these domains in healthy volunteers. Based on the neuropsychological findings, we predicted a disadvantage for nonliving compared to living concepts in the right hemisphere. Our prediction was supported, in that semantic decisions to nonliving concepts were significantly slower and more error-prone when presented to the right hemisphere. In contrast there were no hemisphere differences for living concepts. These findings are consistent with either differential representation or processing of concepts across right and left hemispheres. However, we also found a disadvantage for nonliving things compared to living things in the left hemisphere, which is not consistent with a simple representation account. We discuss these findings in terms of qualitatively different semantic processing in right and left hemispheres within the framework of a distributed model of conceptual representation. PMID:15896386

  1. Mixing metaphors in the cerebral hemispheres: what happens when careers collide?

    PubMed

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

    2012-03-01

    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 2 cerebral hemispheres. For target metaphors presented in the right visual field/left cerebral hemisphere (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 left visual field/right cerebral hemisphere (LVF/RH), matched-sense primes were again additively facilitative. However, alternative-sense primes, though facilitative overall, seemed to eliminate the preexisting 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, flexible, context-dependent coding in the RH.

  2. The contribution of the right cerebral hemisphere to the recovery from aphasia: a single longitudinal case study.

    PubMed

    Ansaldo, Ana Inés; Arguin, Martin; Roch Lecours, André

    2002-08-01

    We examined the role of the right cerebral hemisphere in the recovery from aphasia of HJ, a 50-year-old right-handed and unilingual man who suffered from severe aphasia caused by an extensive left hemisphere (LH) lesion. He was followed-up over 10 months at 4-month intervals, with a lateralized lexical decision task (LDT), an attentional task, and a language battery. Testing started when HJ was 2 months poststroke. In the LDT, words were presented to central vision or lateralized to the left or right visual hemifield. At each test period, we examined the effect of the degree of imageability (high vs. low), and the grammatical class (noun vs. verb) of the targets on HJ's response times and error rates, with left visual field, right visual field, and central vision presentations. The results of the experiment showed that the pattern obtained with the LDT could not be accounted for by fluctuations in attention. There was an interaction of grammatical class with degree of imageability with left visual field displays only. The right hemisphere (RH) was faster with high-imageability words than with low-imageability words, regardless of their grammatical class. There was also an overall RH advantage on response times at 2 and 6 months after onset. This RH predominance coincided with a major recovery of language comprehension and the observation of semantic paralexias, while no major change in language expression was observed at that point. Ten months after onset, the pattern of lateralization changed, and response times for the LDT with either presentation site were equivalent. This LH improvement coincided with some recovery of language expression at the single-word level. The results of this study suggest that, in cases of severe aphasia caused by extensive LH lesions, the RH may play an important role in the recovery process. Furthermore, these results show that the contribution of the two cerebral hemispheres to recovery may vary overtime and affect specific aspects

  3. The contribution of the right cerebral hemisphere to the recovery from aphasia: a single longitudinal case study.

    PubMed

    Ansaldo, Ana Inés; Arguin, Martin; Roch Lecours, André

    2002-08-01

    We examined the role of the right cerebral hemisphere in the recovery from aphasia of HJ, a 50-year-old right-handed and unilingual man who suffered from severe aphasia caused by an extensive left hemisphere (LH) lesion. He was followed-up over 10 months at 4-month intervals, with a lateralized lexical decision task (LDT), an attentional task, and a language battery. Testing started when HJ was 2 months poststroke. In the LDT, words were presented to central vision or lateralized to the left or right visual hemifield. At each test period, we examined the effect of the degree of imageability (high vs. low), and the grammatical class (noun vs. verb) of the targets on HJ's response times and error rates, with left visual field, right visual field, and central vision presentations. The results of the experiment showed that the pattern obtained with the LDT could not be accounted for by fluctuations in attention. There was an interaction of grammatical class with degree of imageability with left visual field displays only. The right hemisphere (RH) was faster with high-imageability words than with low-imageability words, regardless of their grammatical class. There was also an overall RH advantage on response times at 2 and 6 months after onset. This RH predominance coincided with a major recovery of language comprehension and the observation of semantic paralexias, while no major change in language expression was observed at that point. Ten months after onset, the pattern of lateralization changed, and response times for the LDT with either presentation site were equivalent. This LH improvement coincided with some recovery of language expression at the single-word level. The results of this study suggest that, in cases of severe aphasia caused by extensive LH lesions, the RH may play an important role in the recovery process. Furthermore, these results show that the contribution of the two cerebral hemispheres to recovery may vary overtime and affect specific aspects

  4. Motivation, affect, and hemispheric asymmetry: power versus affiliation.

    PubMed

    Kuhl, Julius; Kazén, Miguel

    2008-08-01

    In 4 experiments, the authors examined to what extent information related to different social needs (i.e., power vs. affiliation) is associated with hemispheric laterality. Response latencies to a lateralized dot-probe task following lateralized pictures or verbal labels that were associated with positive or negative episodes related to power, affiliation, or achievement revealed clear-cut laterality effects. These effects were a function of need content rather than of valence: Power-related stimuli were associated with right visual field (left hemisphere) superiority, whereas affiliation-related stimuli were associated with left visual field (right hemisphere) superiority. Additional results demonstrated that in contrast to power, affiliation primes were associated with better discrimination between coherent word triads (e.g., goat, pass, and green, all related to mountain) and noncoherent triads, a remote associate task known to activate areas of the right hemisphere. PMID:18665713

  5. Motivation, affect, and hemispheric asymmetry: power versus affiliation.

    PubMed

    Kuhl, Julius; Kazén, Miguel

    2008-08-01

    In 4 experiments, the authors examined to what extent information related to different social needs (i.e., power vs. affiliation) is associated with hemispheric laterality. Response latencies to a lateralized dot-probe task following lateralized pictures or verbal labels that were associated with positive or negative episodes related to power, affiliation, or achievement revealed clear-cut laterality effects. These effects were a function of need content rather than of valence: Power-related stimuli were associated with right visual field (left hemisphere) superiority, whereas affiliation-related stimuli were associated with left visual field (right hemisphere) superiority. Additional results demonstrated that in contrast to power, affiliation primes were associated with better discrimination between coherent word triads (e.g., goat, pass, and green, all related to mountain) and noncoherent triads, a remote associate task known to activate areas of the right hemisphere.

  6. 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…

  7. Two Sides of Meaning: The Scalp-Recorded N400 Reflects Distinct Contributions from the Cerebral Hemispheres

    PubMed Central

    Wlotko, Edward W.; Federmeier, Kara D.

    2013-01-01

    The N400, a component of the event-related potential (ERP) associated with the processing of meaning, is sensitive to a wide array of lexico-semantic, sentence-level, and discourse-level manipulations across modalities. In sentence contexts, N400 amplitude varies inversely and nearly linearly with the predictability of a word in its context. However, recent theories and empirical evidence from studies employing the visual half-field technique (to selectively bias processing to one cerebral hemisphere) suggest that the two hemispheres use sentence context information in different ways. Thus, each hemisphere may not respond to manipulations of contextual predictability in an equivalent manner. This possibility was investigated by recording ERPs while presenting [in the left and right visual fields (VFs)] sentence-final words that varied over the full range of sentence-level predictability. RVF/left hemisphere items were facilitated (as evidenced by reduced N400 amplitudes) over a broader range of predictability compared with LVF/right hemisphere items, although both strongly predictable and completely unexpected items evoked similar responses in each VF/hemisphere. Further, the pattern of N400 amplitudes over the full range of predictability significantly differed from a linear response function for both VFs/hemispheres. This suggests that the N400 response recorded with standard central field presentation comprises different contributions from both cerebral hemispheres, neither of which on its own is sensitive to contextual predictability in an evenly graded manner. These data challenge the notion of a singular or unitary mode of comprehension and instead support the view that the left and right hemispheres instantiate unique, complementary language comprehension architectures in parallel. PMID:23630506

  8. 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

  9. 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.

  10. Hemispheric Asymmetries in Children's Perception of Nonlinguistic Human Affective Sounds

    ERIC Educational Resources Information Center

    Pollak, Seth D.; Holt, Lori L.; Fries, Alison B. Wismer

    2004-01-01

    In the present work, we developed a database of nonlinguistic sounds that mirror prosodic characteristics typical of language and thus carry affective information, but do not convey linguistic information. In a dichotic-listening task, we used these novel stimuli as a means of disambiguating the relative contributions of linguistic and affective…

  11. Using Ipsilateral Motor Signals in the Unaffected Cerebral Hemisphere as a Signal Platform for Brain Computer Interfaces in Hemiplegic Stroke Survivors

    PubMed Central

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

    2012-01-01

    Objective 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 primarily applied 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. Approach 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 1-dimensional control task. Main Results 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

  12. 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

  13. 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

  14. Study of the language functions controlled by the right hemisphere in patients affected by dementia.

    PubMed

    Motta, M

    1993-01-01

    An insertion test (Shift vs. non-Shift) was performed by eight subjects (mean age 69 years, mean schooling 5.87 years) with clinical diagnosis of suspected Alzheimer disease (AD) in order to reveal right hemisphere cerebral distress in concomitance with damage of the left hemisphere which controls language in AD. Their Shift and non-Shift test scores were significantly lower than those of 28 controls, even if they achieved normal or slightly modified classical language test scores. Shift involves insertion of a syntagma or word in a stimulus-sentence that changes the syntactical relationship of some components of the newly formed sentence, whereas in non-Shift the insertion determines only a change in meaning. Statistical analysis revealed that the difference was not caused by age and schooling. Furthermore, the AD patients achieved significantly lower scores in Shift compared with non-Shift. This indicates greater right hemisphere damage in these patients and confirms its physiological decline in the elderly. The results revealed that the insertion test is more sensitive than classical neurolinguistic tests. They also showed that both superficial (non-Shift) and deep (Shift) types of syntaxes are already compromised in early stages of AD and that they mirror the bilateral thinning which is more pronounced in the right hemisphere. PMID:15374327

  15. Discrete space charge affected field emission: Flat and hemisphere emitters

    SciTech Connect

    Jensen, Kevin L.; Shiffler, Donald A.; Tang, Wilkin; Rittersdorf, Ian M.; Lebowitz, Joel L.; Harris, John R.; Lau, Y. Y.; Petillo, John J.; Luginsland, John W.

    2015-05-21

    Models of space-charge affected thermal-field emission from protrusions, able to incorporate the effects of both surface roughness and elongated field emitter structures in beam optics codes, are desirable but difficult. The models proposed here treat the meso-scale diode region separate from the micro-scale regions characteristic of the emission sites. The consequences of discrete emission events are given for both one-dimensional (sheets of charge) and three dimensional (rings of charge) models: in the former, results converge to steady state conditions found by theory (e.g., Rokhlenko et al. [J. Appl. Phys. 107, 014904 (2010)]) but show oscillatory structure as they do. Surface roughness or geometric features are handled using a ring of charge model, from which the image charges are found and used to modify the apex field and emitted current. The roughness model is shown to have additional constraints related to the discrete nature of electron charge. The ability of a unit cell model to treat field emitter structures and incorporate surface roughness effects inside a beam optics code is assessed.

  16. Prognostic factors in low grade (WHO grade II) gliomas of the cerebral hemispheres: the role of surgery.

    PubMed Central

    Scerrati, M; Roselli, R; Iacoangeli, M; Pompucci, A; Rossi, G F

    1996-01-01

    OBJECTIVE: To assess the role of surgery on survival of patients with grade II gliomas of the cerebral hemispheres. METHODS: One hundred and thirty one low grade hemispheric gliomas surgically treated (biopsied patients excluded) between 1978 and 1989 were retrospectively reviewed. Thalamic, basal ganglia, callosal, or ventricular location were not considered. All tumours were World Health Organisation (WHO) grade II gliomas: 42 fibrillary and 11 gemistocytic astrocytomas, 49 oligodendrogliomas, and 29 oligoastrocytomas. Patients' ages ranged from 14 to 63 (mean 32.9, median 34) years, Karnofsky performance from 0.50 to 0.90 (mean 80.7, median 80), and postsurgical follow up of the living patients from 24 to 190 (mean 97.02, median 93) months. Postoperative external radiotherapy was performed in 49 cases. RESULTS: The overall survival probability at five years was 97.1%, at eight years 76.1%, and at 10 years 62.7% (median survival time 144 months). The impact on survival of the following variables was analysed: age (< 20, 21-40, and > 40 years), Karnofsky score (80-100, 70 < or = 70), histology, tumour extension (T1 < 3 cm, T2 3-5 cm, T3 > 5 cm maximum diameter), extent of surgical resection (S1 radical, S2 subtotal < 10% residual tumour, S3 partial-10%-50% residual tumour), and radiotherapy (either performed or not). A significant positive association with survival at univariate analysis was found for the age group < 20 years (P = 0.003), for total and subtotal surgical resections (S1 and S2; P < 0.001) and for the non-irradiated patients (P = 0.0049), whereas a shorter survival probability was noticed for gemistocytic astrocytomas (P < 0.001) and for tumour extension > 5 cm (T3; P = 0.0193). Karnofsky performance did not show any significant association with survival. The most relevant factor affecting survival at the multivariate analysis was the extent of surgical resection, which resulted as the only variable retaining a significant value (P = 0.001, risk

  17. 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…

  18. Reduction of lipofuscin by centrophenoxine and chlorpromazine in the neurons of rat cerebral hemisphere in primary culture.

    PubMed

    Ohtani, R; Kawashima, S

    1983-01-01

    Cells from neonatal rat cerebral hemispheres were dispersed by trypsin and cultured for 32 days. Histochemical, fluorescence, and electron microscopic analyses demonstrated that lipofuscin pigments increased in neuronal and non-neuronal cells in primary culture according to the lapse of time. When centrophenoxine (10(-4) or 5 X 10(-4) M) or chlorpromazine (10(-6) or 10(-5) M) was added to the medium, the accumulation of lipofuscin pigments in neurons was significantly reduced. However, the effects of these agents were not detected in non-neuronal cells.

  19. Hemispheric asymmetries in bilinguals: tongue similarity affects lateralization of second language.

    PubMed

    D'Anselmo, Anita; Reiterer, Susanne; Zuccarini, Francesca; Tommasi, Luca; Brancucci, Alfredo

    2013-06-01

    It is known that the left hemisphere of the human brain is critical in understanding and producing spoken language, but it remains a topic of great interest determining the cerebral lateralization of multiple languages. The aim of this study is to examine the effects of similarity between languages on hemispheric asymmetry of bilingual brains. The involvement degree of left and right hemisphere was examined during the processing of the first (L1) and second (L2) language in two different groups of bilinguals with English as L2. The first group consisted of German native speakers and the second group of Italian native speakers. Subjects from the two groups acquired L2 later in life (after the age of six) and had a comparable level of proficiency in second language comprehension. The functional lateralization was tested by a classical dichotic test with words in L1 and L2. Dependent variables were number of responses associated to words presented at the left vs. right ear and reaction time. Results showed a significant right ear advantage (REA) for number of responses in both languages and in both groups. However, the REA for L2 (English) processing was stronger in the German group. Reaction times were significantly lower during L1 processing and showed a trend towards the results obtained with the number of response variable. This study provides neuropsychological evidence pointing to a different lateralization pattern in the elaboration of a same L2 if L1 comes from different linguistic roots.

  20. 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

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

    PubMed

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

    2016-08-30

    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

  2. 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

  3. 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

  4. Differences in semantic category priming in the left and right cerebral hemispheres under automatic and controlled processing conditions.

    PubMed

    Collins, M

    1999-08-01

    The contribution of each cerebral hemisphere to the generation of semantic category meanings at automatic and strategic levels of processing was investigated in a priming experiment where prime and target words were independently projected to the left or right visual fields (LVF or RVF). Non-associated category exemplars were employed as related pairs in a lexical decision task and presented in two experimental conditions. The first condition was designed to elicit automatic processing, so related pairs comprised 20% of the positive set, stimulus pairs were temporally separated by a stimulus onset asynchrony (SOA) of 250 ms, and there was no allusion to the presence of related pairs in the instructions to subjects. The second condition, designed to invoke controlled processing, incorporated a relatedness proportion of 50%, stimulus pairs separated by an SOA of 750 ms, and instructions which informed subjects of the presence and use of category exemplar pairs in the stimulus set. In the first condition, a prime directed to either visual field facilitated responses to categorically related targets subsequently projected to the RVF, while in the second condition a prime directed to either visual field facilitated responses to related targets projected to the LVF. The facilitation effects obtained in both conditions appeared to reflect automatic processes, while strategic processes were invoked in the left, but not the right hemisphere in the second condition. The results suggest that both hemispheres have automatic access to semantic category meanings, although the timecourse of activation of semantic category meanings is slower in the right hemisphere than in the left.

  5. Figure-Background Perception and Cerebral Dominance: Hypothesized Integrated Process of Hemispheric Specialization.

    ERIC Educational Resources Information Center

    Ruggieri, Vezio; And Others

    1982-01-01

    The hypothesis was that the two hemispheres have different functions in normal vision, the dominant one analyzing the "figure," and the nondominant the "background." The investigation examined responses of 41 female psychology students. Results were consistent with the hypothesis. (Author/RD)

  6. 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

  7. Somatotopic organization of the medial wall of the cerebral hemispheres: a 3 Tesla fMRI study.

    PubMed

    Mayer, A R; Zimbelman, J L; Watanabe, Y; Rao, S M

    2001-12-01

    Somatotopic organization of the human medial wall of the cerebral hemispheres was studied using functional MRI conducted at high field strength (3 T) with fine spatial resolution ( approximately 2 mm). Healthy subjects performed paced, repetitive movements of the fingers and toes. Within the supplementary motor area (SMA), two regions were identified: finger movements activated a region rostral and superior to that for toe movements. Two activation foci were also identified in the cingulate motor area: toe movements activated a region rostral and ventral to that activated by finger movements. All foci were located between the anterior and posterior commissures. Our results confirm previous human and non-human primate studies regarding the rostral-caudal organization of the SMA and CMA. The dorsal-ventral organization of the CMA, however, appears to be divergent from results derived from cortical stimulation studies conducted in non-human primates.

  8. Selected Gray Matter Volumes and Gender but Not Basal Ganglia nor Cerebellum Gyri Discriminate Left Versus Right Cerebral Hemispheres: Multivariate Analyses in human Brains at 3T.

    PubMed

    Roldan-Valadez, Ernesto; Suarez-May, Marcela A; Favila, Rafael; Aguilar-Castañeda, Erika; Rios, Camilo

    2015-07-01

    Interest in the lateralization of the human brain is evident through a multidisciplinary number of scientific studies. Understanding volumetric brain asymmetries allows the distinction between normal development stages and behavior, as well as brain diseases. We aimed to evaluate volumetric asymmetries in order to select the best gyri able to classify right- versus left cerebral hemispheres. A cross-sectional study performed in 47 right-handed young-adults healthy volunteers. SPM-based software performed brain segmentation, automatic labeling and volumetric analyses for 54 regions involving the cerebral lobes, basal ganglia and cerebellum from each cerebral hemisphere. Multivariate discriminant analysis (DA) allowed the assembling of a predictive model. DA revealed one discriminant function that significantly differentiated left vs. right cerebral hemispheres: Wilks' λ = 0.008, χ(2) (9) = 238.837, P < 0.001. The model explained 99.20% of the variation in the grouping variable and depicted an overall predictive accuracy of 98.8%. With the influence of gender; the selected gyri able to discriminate between hemispheres were middle orbital frontal gyrus (g.), angular g., supramarginal g., middle cingulum g., inferior orbital frontal g., calcarine g., inferior parietal lobule and the pars triangularis inferior frontal g. Specific brain gyri are able to accurately classify left vs. right cerebral hemispheres by using a multivariate approach; the selected regions correspond to key brain areas involved in attention, internal thought, vision and language; our findings favored the concept that lateralization has been evolutionary favored by mental processes increasing cognitive efficiency and brain capacity.

  9. Estradiol levels during the menstrual cycle differentially affect latencies to right and left hemispheres during dichotic listening: an ERP study.

    PubMed

    Tillman, Gail D

    2010-02-01

    Many behavioral studies have found high-estrogen phases of the menstrual cycle to be associated with enhanced left-hemisphere processing and low-estrogen phases to be associated with better right-hemisphere processing. This study examined the changing of hemispheric asymmetry during the menstrual cycle by analyzing event-related potential (ERP) data from midline and both hemispheres of 23 women during their performance of a dichotic tasks shown to elicit a left-hemisphere response (semantic categorization) and a right-hemisphere response (complex tones). Each woman was tested during her high-estrogen follicular phase and low-estrogen menstrual phase. Salivary assays of estradiol and progesterone were used to confirm cycle phase. Analyses of the ERP data revealed that latency for each hemisphere was differentially affected by phase and target side, such that latencies to the left hemisphere and from the right ear were shorter during the high-estrogen phase, and latencies to the right hemisphere and from the left ear were shorter during the low-estrogen phase. These findings supply electrophysiological correlates of the cyclically based interhemispheric differences evinced by behavioral studies.

  10. 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.

  11. [The effect of millimeter-range electromagnetic radiation on the evoked potentials from the vestibular cortical area of the cerebral hemispheres (an experimental study)].

    PubMed

    Mal'tsev, A E; Abakarov, A T

    1994-01-01

    Acute experiments on 20 cats showed that EHF waves of nonthermal intensity can influence evoked potentials (EP) of the exposed vestibular zone of the cerebral hemispheres. Cerebral cortical exposure to low-frequency EHF waves stimulates negative EP component. Higher frequencies (78.33-118 GHz) reduce the above component amplitude. Changes in the positive EP component were minimal. It is suggested that different effects of millimetric waves diverse frequencies are related to the depth of the radiation penetration into the live tissue. The findings can be used in new techniques of physiotherapy.

  12. [Radiotherapy of cerebral tumor in the adult with the exception of hemispheric glioma].

    PubMed

    Bataini, J P; Ennuyer, A; Dhermain, P; Jaulerry, C; Diaz de Bedoya, L V

    1975-01-01

    The results obtained in this series of 120 patients with brain tumors, excepting hemispheric gliomas, appear particularly comforting. Radiosensitiveness of medulloblastomas, pinealomas and to some extent of ependymomas, was of course known. On the contrary, the radio-sensitiveness of some astrocytary processes, or supposed astrocytomas, well or moderately differentiated (gliomas of the IIIrd. ventricle, opto-chiasmatic gliomas, gliomas of the brain stem) appears to have been appreciable and it has been possible to obtain numerous stabilizations equivalent to cures. An histologic chek-up prior to roentgentherapy appears to authors as strictly necessary and might be easily enough obtained thanks to the stereotaxic procedures. Authors are not of mind that the present series will be burdened with radio-necrotic like complications. They think that the tumoral doses might be increased of 5 p. 100 and even of 10 p. 100, while maintaining the same protraction and a fractioning of the same order: treatments of 5 to seven weeks consisting in 5 to 6 sessions per week). It is presently too soon for valuing the efficiency of an adjuvant chemotherapy.

  13. Configural processing of faces in the left and the right cerebral hemispheres.

    PubMed

    Sergent, J

    1984-08-01

    This study investigates the rules by which the component features of faces are combined when presented in the left or the right visual field, and it examines the validity of the analytic-holistic processing dichotomy, using concepts elaborated by Garner (1978, 1981) to specify stimulus properties and models of similarity relations as performance criteria. Latency measures of dissimilarity, obtained for the two visual fields, among a set of eight faces varying on three dimensions of two levels each, were fitted to the dominance metric model, the feature-matching model, the city-block distance metric model, and the Euclidean distance metric model. In addition to a right-visual-field superiority in different responses, a maximum likelihood estimation procedure showed that, for each subject and each visual field, the Euclidean model provided the best fit of the data, suggesting that the faces were compared in terms of their overall similarity. Moreover, the spatial representations of the results revealed interactions among the component facial features in the processing of faces. Taken together, these two findings indicate that faces initially projected to the right or to the left hemisphere were not processed analytically but in terms of their gestalt. PMID:6235319

  14. A Status Report on the SHADOZ (Southern Hemisphere Additional Ozonesondes) Project and Some Issues Affecting Ozone Climatology

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Witte, J. C.; McPeters, R. D.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    SHADOZ aims to support the study of local and global patterns in stratospheric and tropospheric ozone and to provide a data set for the validation for satellite products and model calculations of ozone. Southern hemispheric tropical ozone is of particular interest because this region appears to have complex interplay among photochemical ozone formation (from biomass burning and lightning), stratospheric dynamics, convection and possibly cross-hemispheric transport. Balloon-borne ozone instrumentation (ozonesondes), joined with standard radiosondes for measurement of pressure, temperature and relative humidity, is used to collect profiles throughout the troposphere and lower- to mid-stratosphere. A network of 10 southern hemisphere tropical and subtropical stations, called the Southern Hemisphere ADditional OZonesondes (SHADOZ) project, has been established from operational sites to assemble sonde data for 1998-2000. A status report on the archive, with station operating characteristics, will be given, along with some operational issues that may affect data analysis and interpretation.

  15. What factors affect planetary wave driving in the Southern Hemisphere in spring?

    NASA Astrophysics Data System (ADS)

    Hurwitz, M.; Oman, L.; Newman, P. A.; Nielsen, E.; Bacmeister, J. T.; Molod, A. M.

    2009-12-01

    The timing of the breakup of the Antarctic vortex is determined by planetary wave driving at Southern Hemisphere (SH) mid-latitudes in spring. A previous modeling study found that weaker than observed heat flux in October and November led to a delayed breakup of the Antarctic vortex. In an attempt to better understand the seasonal cycle of SH heat flux at 100hPa and increase wave driving in version 2 of the Goddard Earth Observing System (GEOS) chemistry-climate model (CCM), this work examines the sensitivity of heat flux to a variety of boundary conditions and model parameters. The inclusion of a quasi-biennial oscillation (QBO), the choice of photolysis rates and the representation of gravity wave drag do not affect October/November heat flux. Furthermore, boundary conditions (such as sea surface temperatures) do not determine the heat flux, as the magnitude and seasonal cycle of 100hPa heat flux differs between CCMs using the same ‘recent past’ scenario. Heat flux magnitudes in the critical October/November period, and thus the timing of the vortex breakup, are improved when either the horizontal resolution or SH precipitation is increased.

  16. Dynamic touch is affected in children with cerebral palsy.

    PubMed

    Ocarino, Juliana M; Fonseca, Sergio T; Silva, Paula L P; Gonçalves, Gabriela G P; Souza, Thales R; Mancini, Marisa C

    2014-02-01

    Children with developmental disorders such as cerebral palsy have limited opportunities for effortful interactions with objects and tools. The goal of the study was to investigate whether children with cerebral palsy have deficits in their ability to perceive object length by dynamic touch when compared to typically developing children. Fourteen children with typical development and 12 children with cerebral palsy were asked to report the length of hand-held rods after wielding them out of sight. Multilevel regression models indicated that I1 (maximum principal moment of inertia) was a significant predictor of perceived length - LP (p<.0001). The effect of I1 on LP was significantly different among children (p=.001) and the presence of cerebral palsy (group factor) partially explained such variance (p=.002). In addition, accuracy and reliability of the length judgments made by children with cerebral palsy were significantly lower than the typically developing children (p<.05). Theoretical and clinical implications of these results were identified and discussed.

  17. 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…

  18. Development of Abnormal Hemispheric Vascular Networks Mimicking Cerebral Proliferative Angiopathy in a Child Originally Diagnosed with Deep-Seated Arteriovenous Fistula.

    PubMed

    Sakata, Hiroyuki; Fujimura, Miki; Sato, Kenichi; Niizuma, Kuniyasu; Endo, Hidenori; Tominaga, Teiji

    2016-10-01

    Cerebral proliferative angiopathy (CPA), which is characterized by diffuse vascular abnormalities with intermingled normal brain parenchyma, is a rare clinical entity distinct from classical cerebral arteriovenous malformations. Its pathology at initial state and subsequent course of progression has totally been undetermined. We herein presented a case of a child who was initially diagnosed with deep-seated arteriovenous fistula (AVF), and ultimately developed symptomatic CPA-like vascular lesion over a long period of clinical follow-up. A 7-month-old boy was incidentally found to have an AVF in the right basal ganglia and conservatively followed up. Serial magnetic resonance angiograms revealed the gradual proliferation and enlargement of pial and medullary vessels surrounding the AVF. Seven years later, he had a transient ischemic attack followed by intraventricular hemorrhage. A catheter angiogram showed a diffuse large vascular malformation composed of 2 distinct structures, including AVF in the right basal ganglia and the surrounding proliferated pial and medullary arteries in the right hemisphere. Single-photon emission computed tomography with N-isopropyl[123I]-p-iodoamphetamine revealed apparent hemodynamic compromise on the right hemisphere. Targeted embolization of the pseudoaneurysm originating from the right A1 perforator was performed to prevent rebleeding without complications. The patient had no further cerebrovascular events. Perinidal hypoperfusion induced by a deep-seated AVF could be one of the underlying pathologies of progressive angiogenic activity. This is the first case showing the development of abnormal hemispheric vascular networks mimicking CPA, which offers insight into the pathogenesis of this new entity.

  19. Factors affecting daily activities of patients with cerebral infarction

    PubMed Central

    Liu, Peng; Zhou, Cheng-ye; Zhang, Ying; Wang, Yun-feng; Zou, Chang-lin

    2010-01-01

    BACKGROUND: Stroke is the leading cause of death and long-term disability. This study was undertaken to investigate the factors influencing daily activities of patients with cerebral infarction so as to take interventional measures earlier to improve their daily activities. METHODS: A total of 149 patients with first-episode cerebral infarction were recruited into this prospective study. They were admitted to the Encephalopathy Center, Department of Neurology, the First Affiliated Hospital of Wenzhou Medical College in Zhejiang Province from August 2008 to December 2008. The baseline characteristics of the patients and cerebral infarction risk factors on the first day of admission were recorded. White blood cell (WBC) count, plasma glucose (PG), and many others of laboratory targets were collected in the next morning. Barthel index (BI) was calculated at 2 weeks and 3 months respectively after onset of the disease at the outpatient clinic or by telephone call. Lung infection, urinary tract infection and atrial fibrillation if any were recorded on admission. The National Institute of Health Stroke Scale (NIHSS) scores and the GCS scores were recorded within 24 hours on and after admission, at the second week, and at the third month after the onset of cerebral infarction respectively. RESULTS: The factors of BI at 2 weeks and 3 months after onset were the initial PG level, WBC count and initial NIHSS scores. Besides, urinary tract infection on admission was also the factor for BI at 3 months. CONCLUSION: Active measures should be taken to control these factors to improve the daily activities of patients with cerebral infarction. PMID:25214953

  20. Familiarity differentially affects right hemisphere contributions to processing metaphors and literals.

    PubMed

    Lai, Vicky T; van Dam, Wessel; Conant, Lisa L; Binder, Jeffrey R; Desai, Rutvik H

    2015-01-01

    The role of the two hemispheres in processing metaphoric language is controversial. While some studies have reported a special role of the right hemisphere (RH) in processing metaphors, others indicate no difference in laterality relative to literal language. Some studies have found a role of the RH for novel/unfamiliar metaphors, but not conventional/familiar metaphors. It is not clear, however, whether the role of the RH is specific to metaphor novelty, or whether it reflects processing, reinterpretation or reanalysis of novel/unfamiliar language in general. Here we used functional magnetic resonance imaging (fMRI) to examine the effects of familiarity in both metaphoric and non-metaphoric sentences. A left lateralized network containing the middle and inferior frontal gyri, posterior temporal regions in the left hemisphere (LH), and inferior frontal regions in the RH, was engaged across both metaphoric and non-metaphoric sentences; engagement of this network decreased as familiarity decreased. No region was engaged selectively for greater metaphoric unfamiliarity. An analysis of laterality, however, showed that the contribution of the RH relative to that of LH does increase in a metaphor-specific manner as familiarity decreases. These results show that RH regions, taken by themselves, including commonly reported regions such as the right inferior frontal gyrus (IFG), are responsive to increased cognitive demands of processing unfamiliar stimuli, rather than being metaphor-selective. The division of labor between the two hemispheres, however, does shift towards the right for metaphoric processing. The shift results not because the RH contributes more to metaphoric processing. Rather, relative to its contribution for processing literals, the LH contributes less.

  1. Familiarity differentially affects right hemisphere contributions to processing metaphors and literals

    PubMed Central

    Lai, Vicky T.; van Dam, Wessel; Conant, Lisa L.; Binder, Jeffrey R.; Desai, Rutvik H.

    2015-01-01

    The role of the two hemispheres in processing metaphoric language is controversial. While some studies have reported a special role of the right hemisphere (RH) in processing metaphors, others indicate no difference in laterality relative to literal language. Some studies have found a role of the RH for novel/unfamiliar metaphors, but not conventional/familiar metaphors. It is not clear, however, whether the role of the RH is specific to metaphor novelty, or whether it reflects processing, reinterpretation or reanalysis of novel/unfamiliar language in general. Here we used functional magnetic resonance imaging (fMRI) to examine the effects of familiarity in both metaphoric and non-metaphoric sentences. A left lateralized network containing the middle and inferior frontal gyri, posterior temporal regions in the left hemisphere (LH), and inferior frontal regions in the RH, was engaged across both metaphoric and non-metaphoric sentences; engagement of this network decreased as familiarity decreased. No region was engaged selectively for greater metaphoric unfamiliarity. An analysis of laterality, however, showed that the contribution of the RH relative to that of LH does increase in a metaphor-specific manner as familiarity decreases. These results show that RH regions, taken by themselves, including commonly reported regions such as the right inferior frontal gyrus (IFG), are responsive to increased cognitive demands of processing unfamiliar stimuli, rather than being metaphor-selective. The division of labor between the two hemispheres, however, does shift towards the right for metaphoric processing. The shift results not because the RH contributes more to metaphoric processing. Rather, relative to its contribution for processing literals, the LH contributes less. PMID:25713522

  2. The role of the right hemisphere in the control of speech prosody in propositional and affective contexts.

    PubMed

    Shapiro, B E; Danly, M

    1985-05-01

    Sixteen right-handed adult males with localized insult to either the right or left hemisphere and five control subjects without brain damage read aloud target sentences embedded in paragraphs, while intoning their voices in either a declarative, interrogative, happy, or sad mode. Acoustical analysis of the speech wave was performed. Right-anterior (pre-Rolandic) and right-central (pre- and post-Rolandic) brain-damaged patients spoke with less pitch variation and restricted intonational range across emotional and nonemotional domains, while patients with right posterior (post-Rolandic) damage had exaggerated pitch variation and intonational range across both domains. No such deficits were found in patients with left posterior damage, whose prosody was similar to that of normal control subjects. It is suggested that damage to the right hemisphere alone may result in a primary disturbance of speech prosody that may be independent of the disturbances in affect often noted in right-brain-damaged populations. PMID:4027566

  3. 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. PMID:26808450

  4. SOD1 overexpression prevents acute hyperglycemia-induced cerebral myogenic dysfunction: relevance to contralateral hemisphere and stroke outcomes

    PubMed Central

    Coucha, Maha; Li, Weiguo; Hafez, Sherif; Abdelsaid, Mohammed; Johnson, Maribeth H.; Fagan, Susan C.

    2014-01-01

    Admission hyperglycemia (HG) amplifies vascular injury and neurological deficits in acute ischemic stroke, but the mechanisms remain controversial. We recently reported that ischemia-reperfusion (I/R) injury impairs the myogenic response in both hemispheres via increased nitration. However, whether HG amplifies contralateral myogenic dysfunction and whether loss of tone in the contralateral hemisphere contributes to stroke outcomes remain to be determined. Our hypothesis was that contralateral myogenic dysfunction worsens stroke outcomes after acute hyperglycemic stroke in an oxidative stress-dependent manner. Male wild-type or SOD1 transgenic rats were injected with saline or 40% glucose solution 10 min before surgery and then subjected to 30 min of ischemia/45 min or 24 h of reperfusion. In another set of animals (n = 5), SOD1 was overexpressed only in the contralateral hemisphere by stereotaxic adenovirus injection 2–3 wk before I/R. Myogenic tone and neurovascular outcomes were determined. HG exacerbated myogenic dysfunction in contralateral side only, which was associated with infarct size expansion, increased edema, and more pronounced neurological deficit. Global and selective SOD1 overexpression restored myogenic reactivity in ipsilateral and contralateral sides, respectively, and enhanced neurovascular outcomes. In conclusion, our results show that SOD1 overexpression nullified the detrimental effects of HG on myogenic tone and stroke outcomes and that the contralateral hemisphere may be a novel target for the management of acute hyperglycemic stroke. PMID:25552308

  5. Enhanced activation of the left hemisphere promotes normative decision making.

    PubMed

    Corser, Ryan; Jasper, John D

    2014-01-01

    Previous studies have reported that enhanced activation of the left cerebral hemisphere reduces risky-choice, attribute, and goal-framing effects relative to enhanced activation of the right cerebral hemisphere. The present study sought to extend these findings and show that enhanced activation of the left hemisphere also reduces violations of other normative principles, besides the invariance principle. Participants completed ratio bias (Experiment 1, N = 296) and base rate neglect problems (Experiment 2, N = 145) under normal (control) viewing or with the right or left hemisphere primarily activated by imposing a unidirectional gaze. In Experiment 1 we found that enhanced left hemispheric activation reduced the ratio bias relative to normal viewing and a group experiencing enhanced right hemispheric activation. In Experiment 2 enhanced left hemispheric activation resulted in using base rates more than normal viewing, but not significantly more than enhanced right hemispheric activation. Results suggest that hemispheric asymmetries can affect higher-order cognitive processes, such as decision-making biases. Possible theoretical accounts are discussed as well as implications for dual-process theories.

  6. Congenital Unilateral Deafness Affects Cerebral Organization of Reading

    PubMed Central

    Adorni, Roberta; Manfredi, Mirella; Proverbio, Alice Mado

    2013-01-01

    It is known that early sensory deprivation modifies brain functional structure and connectivity. The aim of the present study was to investigate the neuro-functional organization of reading in a patient with profound congenital unilateral deafness. Using event-related potentials (ERPs), we compared cortical networks supporting the processing of written words in patient RA (completely deaf in the right ear since birth) and in a group of control volunteers. We found that congenital unilateral hearing deprivation modifies neural mechanisms of word reading. Indeed, while written word processing was left-lateralized in controls, we found a strong right lateralization of the fusiform and inferior occipital gyri activation in RA. This finding goes in the same direction of recent proposals that the ventral occipito-temporal activity in word reading seem to lateralize to the same hemisphere as the one involved in spoken language processing. PMID:24961430

  7. 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)

  8. Fetal-Type Variants of the Posterior Cerebral Artery and Concurrent Infarction in the Major Arterial Territories of the Cerebral Hemisphere.

    PubMed

    Lambert, Stephen L; Williams, Frank J; Oganisyan, Zhora Z; Branch, Lionel A; Mader, Edward C

    2016-01-01

    Fetal-type or fetal posterior cerebral artery (FPCA) is a variant of cerebrovascular anatomy in which the distal posterior cerebral artery (PCA) territory is perfused by a branch of the internal carotid artery (ICA). In the presence of FPCA, thromboembolism in the anterior circulation may result in paradoxical PCA territory infarction with or without concomitant infarction in the territories of the middle (MCA) or the anterior (ACA) cerebral artery. We describe 2 cases of FPCA and concurrent acute infarction in the PCA and ICA territories-right PCA and MCA in Patient 1 and left PCA, MCA, and ACA in Patient 2. Noninvasive angiography detected a left FPCA in both patients. While FPCA was clearly the mechanism of paradoxical infarction in Patient 2, it turned out to be an incidental finding in Patient 1 when evidence of a classic right PCA was uncovered from an old computed tomography scan image. Differences in anatomical details of the FPCA in each patient suggest that the 2 FPCAs are developmentally different. The FPCA of Patient 1 appeared to be an extension of the embryonic left posterior communicating artery (PcomA). Patient 2 had 2 PCAs on the left (PCA duplication), classic bilateral PCAs, and PcomAs, and absent left anterior choroidal artery (AchoA), suggesting developmental AchoA-to-FPCA transformation on the left. These 2 cases underscore the variable anatomy, clinical significance, and embryological origins of FPCA variants. PMID:27660767

  9. Fetal-Type Variants of the Posterior Cerebral Artery and Concurrent Infarction in the Major Arterial Territories of the Cerebral Hemisphere

    PubMed Central

    Lambert, Stephen L.; Williams, Frank J.; Oganisyan, Zhora Z.; Branch, Lionel A.; Mader, Edward C.

    2016-01-01

    Fetal-type or fetal posterior cerebral artery (FPCA) is a variant of cerebrovascular anatomy in which the distal posterior cerebral artery (PCA) territory is perfused by a branch of the internal carotid artery (ICA). In the presence of FPCA, thromboembolism in the anterior circulation may result in paradoxical PCA territory infarction with or without concomitant infarction in the territories of the middle (MCA) or the anterior (ACA) cerebral artery. We describe 2 cases of FPCA and concurrent acute infarction in the PCA and ICA territories—right PCA and MCA in Patient 1 and left PCA, MCA, and ACA in Patient 2. Noninvasive angiography detected a left FPCA in both patients. While FPCA was clearly the mechanism of paradoxical infarction in Patient 2, it turned out to be an incidental finding in Patient 1 when evidence of a classic right PCA was uncovered from an old computed tomography scan image. Differences in anatomical details of the FPCA in each patient suggest that the 2 FPCAs are developmentally different. The FPCA of Patient 1 appeared to be an extension of the embryonic left posterior communicating artery (PcomA). Patient 2 had 2 PCAs on the left (PCA duplication), classic bilateral PCAs, and PcomAs, and absent left anterior choroidal artery (AchoA), suggesting developmental AchoA-to-FPCA transformation on the left. These 2 cases underscore the variable anatomy, clinical significance, and embryological origins of FPCA variants.

  10. Fetal-Type Variants of the Posterior Cerebral Artery and Concurrent Infarction in the Major Arterial Territories of the Cerebral Hemisphere

    PubMed Central

    Lambert, Stephen L.; Williams, Frank J.; Oganisyan, Zhora Z.; Branch, Lionel A.; Mader, Edward C.

    2016-01-01

    Fetal-type or fetal posterior cerebral artery (FPCA) is a variant of cerebrovascular anatomy in which the distal posterior cerebral artery (PCA) territory is perfused by a branch of the internal carotid artery (ICA). In the presence of FPCA, thromboembolism in the anterior circulation may result in paradoxical PCA territory infarction with or without concomitant infarction in the territories of the middle (MCA) or the anterior (ACA) cerebral artery. We describe 2 cases of FPCA and concurrent acute infarction in the PCA and ICA territories—right PCA and MCA in Patient 1 and left PCA, MCA, and ACA in Patient 2. Noninvasive angiography detected a left FPCA in both patients. While FPCA was clearly the mechanism of paradoxical infarction in Patient 2, it turned out to be an incidental finding in Patient 1 when evidence of a classic right PCA was uncovered from an old computed tomography scan image. Differences in anatomical details of the FPCA in each patient suggest that the 2 FPCAs are developmentally different. The FPCA of Patient 1 appeared to be an extension of the embryonic left posterior communicating artery (PcomA). Patient 2 had 2 PCAs on the left (PCA duplication), classic bilateral PCAs, and PcomAs, and absent left anterior choroidal artery (AchoA), suggesting developmental AchoA-to-FPCA transformation on the left. These 2 cases underscore the variable anatomy, clinical significance, and embryological origins of FPCA variants. PMID:27660767

  11. 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…

  12. 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.

  13. 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.

  14. Infarct hemisphere and noninfarcted brain volumes affect locomotor performance following stroke

    PubMed Central

    Chen, I-Hsuan; Novak, Vera

    2014-01-01

    Objective: Brain damage within the right middle cerebral artery (MCA) territory is particularly disruptive to mediolateral postural stabilization. The objective of this cross-sectional study was to test the hypothesis that chronic right MCA infarcts (as compared to left) are associated with slower and more bilaterally asymmetrical gait. We further hypothesized that in those with chronic right MCA infarct, locomotor performance is more dependent on gray matter (GM) volumes within noninfarcted regions of the brain that are involved in motor control yet lie outside of the MCA territory. Methods: Gait speed was assessed in 19 subjects with right MCA infarct, 20 with left MCA infarct, and 108 controls. Bilateral plantar pressure and temporal symmetry ratios were calculated in a subset of the cohort. GM volumes within 5 regions outside of the MCA territory (superior parietal lobe, precuneus, caudate, putamen, and cerebellum) were quantified from anatomic MRIs. Results: Right and left infarct groups had similar poststroke duration (7.6 ± 6.0 years), infarct size, and functional independence. The right infarct group demonstrated slower gait speed and greater asymmetry compared to the left infarct group and controls (p < 0.05). In the right infarct group only, those with larger GM volumes within the cerebellum (r2 = 0.32, p = 0.02) and caudate (r2 = 0.56, p < 0.001) exhibited faster gait speed. Conclusion: Individuals with chronic lesions within the right MCA territory, as compared to the left MCA territory, exhibit slower, more asymmetrical gait. For these individuals, larger GM volumes within regions outside of the infarcted vascular territory may help preserve locomotor control. PMID:24489132

  15. 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…

  16. 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…

  17. [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.

  18. Development affects in vitro vascular tone and calcium sensitivity in ovine cerebral arteries

    PubMed Central

    Geary, Greg G; Osol, George J; Longo, Lawrence D

    2004-01-01

    We have shown recently that development from neonatal to adult life affects cerebrovascular tone of mouse cerebral arteries through endothelium-derived vasodilatory mechanisms. The current study tested the hypothesis that development from fetal to adult life affects cerebral artery vascular smooth muscle (VSM) [Ca2+]i sensitivity and tone through a mechanism partially dependent upon endothelium-dependent signalling. In pressurized resistance sized cerebral arteries (∼150 μm) from preterm (95 ± 2 days gestation (95 d)) and near-term (140 ± 2 days gestation (140 d)) fetuses, and non-pregnant adults, we measured vascular diameter (μm) and [Ca2+]i (nm) as a function of intravascular pressure. We repeated these studies in the presence of inhibition of nitric oxide synthase (NOS; with l-NAME), cyclo-oxygenase (COX; with indomethacin) and endothelium removal (E–). Cerebrovasculature tone (E+) was greater in arteries from 95 d fetuses and adults compared to 140 d sheep. Ca2+ sensitivity was similar in 95 d fetuses and adults, but much lower in 140 d fetuses. Removal of endothelium resulted in a reduction in lumen diameter as a function of pressure (greater tone) in all treatment groups. [Ca2+]i sensitivity differences among groups were magnified after E–. NOS inhibition decreased diameter as a function of pressure in each age group, with a significant increase in [Ca2+]i to pressure ratio only in the 140 d fetuses. Indomethacin increased tone and increased [Ca2+]i in the 140 d fetuses, but not the other age groups. Development from near-term to adulthood uncovered an interaction between NOS- and COX-sensitive substances that functioned to modulate artery diameter but not [Ca2+]i. This study suggests that development is associated with significant alterations in cerebral vascular smooth muscle (VSM), endothelium, NOS and COX responses to intravascular pressure. We speculate that these changes have important implications in the regulation of cerebral blood flow in

  19. Significant proteins affecting cerebral vasospasm using complementary ICPMS and MALDI-MS.

    PubMed

    Easter, Renee N; Barry, Colin G; Pyne-Geithman, Gail; Caruso, Joseph A

    2012-01-01

    Cerebral vasospasm (CV) following subarachnoid hemorrhagic stroke affects more than one million people each year. The etiology and prevention of CV is currently of great interest to researchers in various fields of medical science. More recently, the idea that selenium could be playing a major role in the onset of cerebral vasospasm has come into the spotlight. This study focused on using newly established metallomics techniques in order to explore the proteome associated with CV and if selenium might affect the discovered proteins. Size exclusion chromatography coupled to inductively coupled plasma mass spectrometry, along with LC-MALDI-TOF/TOF were both essential in determining protein identifications in three different sample types; a control (normal, healthy patient, CSF control), SAH stroke patients (no vasospasm, CSF C) and SAH CV patients (CSF V). The results of this study, although preliminary, indicate the current methods are applicable and warrant further application to these clinically important targets.

  20. Inhibitory theta burst stimulation of affected hemisphere in chronic stroke: a proof of principle, sham-controlled study.

    PubMed

    Di Lazzaro, Vincenzo; Rothwell, John C; Talelli, Penelope; Capone, Fioravante; Ranieri, Federico; Wallace, Amanda C; Musumeci, Gabriella; Dileone, Michele

    2013-10-11

    Non-invasive brain stimulation is presently being tested as a potential therapeutic intervention for stroke rehabilitation. Following a model of competitive interactions between the hemispheres, these interventions aim to increase the plasticity of stroke hemisphere by applying either excitatory protocols to the damaged hemisphere or inhibitory protocols to the non-stroke hemisphere. Here we test the safety and feasibility of using an inhibitory protocol on the stroke hemisphere to improve the response to conventional therapy via a homeostatic increase in learning capacity. Twelve chronic stroke patients received TBS to stroke hemisphere (6 patients inhibitory TBS and 6 sham TBS) followed by physical therapy daily for 10 working days. Patients and therapists were blinded to the type of TBS. Action Research Arm Test (ARAT), Nine-Hole Pegboard Test (NHPT) and Jebsen-Taylor Test (JTT) were the primary outcome measures, grip and pinch-grip dynamometry were the secondary outcome measures. All patients improved ARAT and JTT scores for up to 3 months post-treatment. ARAT scores improved significantly in both real and sham groups, but only patients receiving real TBS significantly improved on the JTT: 3 months post-treatment mean execution time was reduced compared to baseline by 141 s for real group and by 65s for the sham group. This small exploratory study suggests that ipsilesional inhibitory TBS is safe and that it has the potential to be used in a larger trial to enhance the gain from a late rehabilitation program in chronic stroke patients. PMID:23978513

  1. Sign language aphasia following right hemisphere damage in a left-hander: a case of reversed cerebral dominance in a deaf signer?

    PubMed

    Pickell, Herbert; Klima, Edward; Love, Tracy; Kritchevsky, Mark; Bellugi, Ursula; Hickok, Gregory

    2005-06-01

    Recent lesion studies have shown that left hemisphere lesions often give rise to frank sign language aphasias in deaf signers, whereas right hemisphere lesions do not, suggesting similar patterns of hemispheric asymmetry for signed and spoken language. We present here a case of a left-handed, deaf, life-long signer who became aphasic after a right-hemisphere lesion. The subject exhibits deficits in sign language comprehension and production typically associated with left hemisphere damaged signers. He also exhibits evidence of local versus global deficits similar to left-hemisphere lesioned hearing patients. This case represents reversed lateralization for sign language and also may represent reversed lateralization for visuo-spatial abilities in a deaf signer.

  2. Cerebral oxygen metabolism and blood flow in human cerebral ischemic infarction

    SciTech Connect

    Lenzi, G.L.; Frackowiak, R.S.; Jones, T.

    1982-09-01

    Fifteen patients with acute cerebral hemispheric infarcts have been studied with positron emission tomography and the /sup 15/O steady-state inhalation technique. Thirteen follow-up studies were also performed. The values of cerebral oxygen metabolism (CMRO/sub 2/), cerebral blood flow (CBF), and oxygen extraction ration (OER) have been calculated for the infarcted regions, their borders, the symmetrical regions in contralateral cerebral hemispheres, and the cerebellar hemispheres. This study demonstrates that in the completed stroke there are thresholds for regional CMRO/sub 2/ and regional CBF below which the general clinical outcome of the patients is usually poor. The ischaemic lesions invariably produce an uncoupling between the greatly decreased metabolic demand and the less affected blood supply, with very frequent instances of relative hyperperfusion. Remote effects of the hemispheric infarcts have been demonstrated, such as crossed cerebellar diaschisis and contralateral transhemispheric depression. The level of consciousness correlates with oxygen uptake and blood flow both in the posterior fossa and in the contralateral cerebral hemispheres. The follow-up studies of individual patients underline the high variability of metabolism-to-flow balance during the acute phase of the illness, and stress the need for more studies focused on repeated assessments of homogeneous patient populations.

  3. 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…

  4. How measurement artifacts affect cerebral autoregulation outcomes: A technical note on transfer function analysis.

    PubMed

    Meel-van den Abeelen, Aisha S S; de Jong, Daan L K; Lagro, Joep; Panerai, Ronney B; Claassen, Jurgen A H R

    2016-05-01

    Cerebral autoregulation (CA) is the mechanism that aims to maintain adequate cerebral perfusion during changes in blood pressure (BP). Transfer function analysis (TFA), the most reported method in literature to quantify CA, shows large between-study variability in outcomes. The aim of this study is to investigate the role of measurement artifacts in this variation. Specifically, the role of distortion in the BP and/or CBFV measurementon TFA outcomes was investigated. The influence of three types of artifacts on TFA outcomes was studied: loss of signal, motion artifacts, and baseline drifts. TFA metrics of signals without the simulated artifacts were compared with those of signals with artifacts. TFA outcomes scattered highly when more than 10% of BP signal or over 8% of the CBFV signal was lost, or when measurements contained one or more artifacts resulting from head movement. Furthermore, baseline drift affected interpretation of TFA outcomes when the power in the BP signal was 5 times the power in the LF band. In conclusion, loss of signal in BP and loss in CBFV, affects interpretation of TFA outcomes. Therefore, it is vital to validate signal quality to the defined standards before interpreting TFA outcomes. PMID:26935320

  5. 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 ...

  6. Altered Cerebral Perfusion in Executive, Affective, and Motor Networks During Adolescent Depression

    PubMed Central

    Ho, Tiffany C.; Wu, Jing; Shin, David D.; Liu, Thomas T.; Tapert, Susan F.; Yang, Guang; Connolly, Colm G.; Frank, Guido K.W.; Max, Jeffrey E.; Wolkowitz, Owen; Eisendrath, Stuart; Hoeft, Fumiko; Banerjee, Dipavo; Hood, Korey; Hendren, Robert L.; Paulus, Martin P.; Simmons, Alan N.; Yang, Tony T.

    2013-01-01

    Objective While substantial literature has reported regional cerebral blood flow (rCBF) abnormalities in adults with depression, these studies commonly necessitated the injection of radioisotopes into subjects. The recent development of arterial spin labeling (ASL), however, allows for noninvasive measurements of rCBF. Currently, no published ASL studies have examined cerebral perfusion in adolescents with depression. Thus, the aim of the present study was to examine baseline cerebral perfusion in adolescent depression using a newly developed ASL technique: pseudocontinuous arterial spin labeling (PCASL). Method 25 medication-naive adolescents (ages 13–17 years) diagnosed with major depressive disorder (MDD) and 26 well-matched controls underwent functional magnetic resonance imaging. Baseline rCBF was measured via a novel PCASL method that optimizes tagging efficiency. Results Voxel-based whole brain analyses revealed significant frontal, limbic, paralimbic, and cingulate hypoperfusion in the group with depression (p<0.05, corrected). Hyperperfusion was also observed within the subcallosal cingulate, putamen, and fusiform gyrus (p<0.05, corrected). Similarly, region-of-interest analyses revealed amygdalar and insular hypoperfusion in the group with depression, as well as hyperperfusion in the putamen and superior insula (p<0.05, corrected). Conclusions Adolescents with depression and healthy adolescents appear to differ on rCBF in executive, affective, and motor networks. Dysfunction in these regions may contribute to the cognitive, emotional, and psychomotor symptoms commonly present in adolescent depression. These findings point to possible biomarkers for adolescent depression that could inform early interventions and treatments and establishes a methodology for using PCASL to noninvasively measure rCBF in clinical and healthy adolescent populations. PMID:24074474

  7. Hemispheric interaction, metacontrol, and mnemonic processing in split-brain macaques.

    PubMed

    Kavcic, V; Fei, R; Hu, S; Doty, R W

    2000-06-15

    These experiments explored the interactions remaining between the cerebral hemispheres in two split-brain macaques. The 'split' was earlier confirmed by showing that one hemisphere was incapable of identifying visual images seen by the other. The critical tests for residual interactions were intermingled with control trials in a continuous recognition task. These tests were of two kinds: 'parallel processing', to determine how simultaneous viewing by both hemispheres affected subsequent recognition by one of them alone; and 'conflict', where opposite responses were demanded from the two hemispheres, thus assessing the issue of metacontrol. Two types of stimuli were also employed: ART, in which each hemisphere saw essentially the same image; and BIPARTITE, in which images were entirely different for each hemisphere. Since, with either type of stimulus, performance was best when viewed by both hemispheres at both encoding and retrieval, 'parallel processing' was highly efficient. However, when both hemispheres viewed initially and only one was subsequently queried, performance was significantly worse than when each hemisphere acted alone on each occasion. It is thus reasoned that when both hemisphere view together, the resultant memory trace somehow reflects the bilaterality, a conclusion concordant with observations of Marcel on blindsight. Processing different images (BIPARTITE) was somewhat more disruptive in this regard than if the same image was viewed by each hemisphere. This was particularly true in the conflict situation, where for one hemisphere the item seen was NEW and for the other it was OLD. A response of 'OLD' was, at first, consistently rewarded. When this well-established protocol was changed, the hemispheres in each animal were gradually able to revise their joint behavior. This, together with the effect of disparate images, and the deficiency evoked when the animals were forced to recognize unilaterally an image first viewed under bilateral

  8. [The asymmetry of cerebral hemispheric activity in dogs in a state of quiet wakefulness under the action of sensory stimuli and food deprivation].

    PubMed

    Preobrazhenskaia, L A

    1999-01-01

    The EEG was recorded in four dogs from symmetrical cortical areas of the left and right brain hemispheres. Activation foci were determined by the maximal values of the mean frequency of EEG oscillations and coherence function. In the background experiments, the hemispheric activation asymmetry was observed in all dogs. The individual differences were in the frequency ranges, which were asymmetrically localized. In three dogs the coherence level was significantly more frequently higher in the right hemisphere than in the left one, in one dog the opposite relations were observed. These differences in activation foci localization were correlated with different tactics of choice between two feeders under conditions of free behavior. Under the action of external stimuli, changes in hemispheric activation were observed, predominantly, in the corresponding projection areas, and at the shifts of food excitability they were localized in symmetrical frontal areas. The results suggest that the left hemisphere becomes more activated during the first presentations of indifferent stimuli, i.e., during the development of the reaction to novelty, and under conditions of food deprivation, which rises the level of brain activation.

  9. 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

  10. [Transcranial magnetic electro-stimulation with alternate action on brain hemispheres in the correction of cerebral disturbances in children with diabetes mellitus type 1].

    PubMed

    Filina, N Iu; Bolotova, N V; Raĭgorodskiĭ, Iu M; Nikolaeva, N V

    2012-01-01

    Correction of psychoemotional and autonomic disturbances in children 7-17 years old with diabetes mellitus type 1 was conducted using transcranial magnetic electro-stimulation with alternate action on brain hemispheres (main group, 42 patients). The method includes the combined action of magnetic field pulses and series of electric impulses; magnetic and electric stimulation were performed synchronously - at first, on one brain hemisphere, then on another hemisphere with alternation frequency 9.5-10.5 Hz. A comparison group consisted of 44 patients with diabetes mellitus type 1 who received physiotherapeutic treatment as a combination of transcranial magnetic therapy and electro-stimulation with simultaneous action on both brain hemispheres. Treatment duration was 10 sessions. Treatment efficacy was assessed by the decrease in frequency and intensity of complaints, improvement of patient's health status measured (a scale for assessment of activity, health perception and mood) and improvement of the status of the autonomic nervous system (Vein's questionnaire), mental sphere (the Luscher color test) and cognitive traits (The Concentrated Attention Test of the Toulouse-Pierron Factorial Battery). The status of the autonomic nervous system was evaluated before and after the treatment using cardiointervalography. Brain bioelectrical activity was assessed using encephalography. Significant reduction of autonomic, psychoemotional and cognitive disturbances, normalization of brain bioelectrical activity due to the α-rhythm organization and arrhythmia removal were identified in the main group after the treatment. No adverse effects of this physiotherapeutic treatment was found.

  11. 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

  12. 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 ...

  13. [A study on functional plasticity of the brain in childhood. II. Speech development and intelligence after the damage of cerebral hemisphere under 1 year of age].

    PubMed

    Ichiba, N; Takigawa, H

    1992-11-01

    To investigate the functional plasticity of the brain in childhood, the speech development, the intelligence test and dichotic listening test were performed on 27 patients who had suffered from hemiplegia under 1 year of age. Among 13 patients with right hemiplegia, 7 to 24 years old, 11 patients showed a left ear dominance suggesting the lateralization of language in the right hemisphere. All 14 patients with left hemiplegia, 5 to 37 years old, showed a right ear dominance suggesting the lateralization of language in the left hemisphere. All 27 patients acquired speech function enough to converse with other people during daily life. There were no differences in speech development or intelligence scores between both groups of hemiplegia. Although there was no correlation between the speech development and the age of onset of hemiplegia, there was a correlation between the speech development and the intelligence score in both groups of hemiplegia. PMID:1419166

  14. 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.

  15. 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…

  16. 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…

  17. Functional representation of living and nonliving domains across the cerebral hemispheres: a combined event-related potential/transcranial magnetic stimulation study.

    PubMed

    Fuggetta, Giorgio; Rizzo, Silvia; Pobric, Gorana; Lavidor, Michal; Walsh, Vincent

    2009-02-01

    Transcranial magnetic stimulation (TMS) over the left hemisphere has been shown to disrupt semantic processing but, to date, there has been no direct demonstration of the electrophysiological correlates of this interference. To gain insight into the neural basis of semantic systems, and in particular, study the temporal and functional organization of object categorization processing, we combined repetitive TMS (rTMS) and ERPs. Healthy volunteers performed a picture-word matching task in which Snodgrass drawings of natural (e.g., animal) and artifactual (e.g., tool) categories were associated with a word. When short trains of high-frequency rTMS were applied over Wernicke's area (in the region of the CP5 electrode) immediately before the stimulus onset, we observed delayed response times to artifactual items, and thus, an increased dissociation between natural and artifactual domains. This behavioral effect had a direct ERP correlate. In the response period, the stimuli from the natural domain elicited a significant larger late positivity complex than those from the artifactual domain. These differences were significant over the centro-parietal region of the right hemisphere. These findings demonstrate that rTMS interferes with post-perceptual categorization processing of natural and artifactual stimuli that involve separate subsystems in distinct cortical areas. PMID:18510439

  18. 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

  19. Impact of Intraoperative Events on Cerebral Tissue Oximetry in Patients Undergoing Cardiopulmonary Bypass.

    PubMed

    Ševerdija, Ervin E; Vranken, Nousjka P A; Teerenstra, Steven; Ganushchak, Yuri M; Weerwind, Patrick W

    2015-03-01

    Previous studies showed that decreased cerebral saturation during cardiac surgery is related to adverse postoperative outcome. Therefore, we investigated the influence of intraoperative events on cerebral tissue saturation in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). A total of 52 adult patients who underwent cardiac surgery using pulsatile CPB were included in this prospective explorative study. Cerebral tissue oxygen saturation (SctO2) was measured in both the left and right cerebral hemisphere. Intraoperative events, involving interventions performed by anesthesiologist, surgeon, and clinical perfusionist, were documented. Simultaneously, in-line hemodynamic parameters (partial oxygen pressure, partial carbon dioxide pressure, hematocrit, arterial blood pressure, and CPB flow rates) were recorded. Cerebral tissue saturation was affected by anesthetic induction (p < .001), placement of the sternal retractor (p < .001), and initiation (p < .001) as well as termination of CPB (p < .001). Placement (p < .001) and removal of the aortic cross-clamp (p = .026 for left hemisphere, p = .048 for right hemisphere) led to changes in cerebral tissue saturation. In addition, when placing the aortic crossclamp, hematocrit (p < .001) as well as arterial (p = .007) and venous (p < .001) partial oxygen pressures changed. Cerebral tissue oximetry effectively identifies changes related to surgical events or vulnerable periods during cardiac surgery. Future studies are needed to identify methods of mitigating periods of reduced cerebral saturation.

  20. 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…

  1. Imagery use and affective responses during exercise: an examination of cerebral hemodynamics using near-infrared spectroscopy.

    PubMed

    Tempest, Gavin; Parfitt, Gaynor

    2013-10-01

    Imagery, as a cognitive strategy, can improve affective responses during moderate-intensity exercise. The effects of imagery at higher intensities of exercise have not been examined. Further, the effect of imagery use and activity in the frontal cortex during exercise is unknown. Using a crossover design (imagery and control), activity of the frontal cortex (reflected by changes in cerebral hemodynamics using near-infrared spectroscopy) and affective responses were measured during exercise at intensities 5% above the ventilatory threshold (VT) and the respiratory compensation point (RCP). Results indicated that imagery use influenced activity of the frontal cortex and was associated with a more positive affective response at intensities above VT, but not RCP to exhaustion (p < .05). These findings provide direct neurophysiological evidence of imagery use and activity in the frontal cortex during exercise at intensities above VT that positively impact affective responses. PMID:24197718

  2. Imagery use and affective responses during exercise: an examination of cerebral hemodynamics using near-infrared spectroscopy.

    PubMed

    Tempest, Gavin; Parfitt, Gaynor

    2013-10-01

    Imagery, as a cognitive strategy, can improve affective responses during moderate-intensity exercise. The effects of imagery at higher intensities of exercise have not been examined. Further, the effect of imagery use and activity in the frontal cortex during exercise is unknown. Using a crossover design (imagery and control), activity of the frontal cortex (reflected by changes in cerebral hemodynamics using near-infrared spectroscopy) and affective responses were measured during exercise at intensities 5% above the ventilatory threshold (VT) and the respiratory compensation point (RCP). Results indicated that imagery use influenced activity of the frontal cortex and was associated with a more positive affective response at intensities above VT, but not RCP to exhaustion (p < .05). These findings provide direct neurophysiological evidence of imagery use and activity in the frontal cortex during exercise at intensities above VT that positively impact affective responses.

  3. 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.

  4. 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.

  5. Outgoing Hemisphere

    NASA Technical Reports Server (NTRS)

    1974-01-01

    This mosaic shows the planet Mercury as seen by Mariner 10 as it sped away from the planet on March 29, 1974. The mosaic was made from over 140 individual TV frames taken about two hours after encounter, at a range of 37,300 miles (60,000 kilometers). North is at top. The limb is at right, as is the illuminating sunlight. The equator crosses the planet about two-thirds of the way from the top of the disc. The terminator, line-separating day from night, is about 190 degrees west longitude. The planet shows a gibbous disc-more than half-illuminated. This hemisphere is dominated by smooth plains, rather than heavily cratered terrain, and resembles portions of the Moon's maria in general shape. Half of a very large, multi-ringed basin named Caloris Basin appears near the center of the disc near the terminator. Its surrounding mountain ring is 800 miles (1,300 kilometers) in diameter.

    The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.

    Image Credit: NASA/JPL/Northwestern University

  6. Cerebral palsy

    MedlinePlus

    ... with pain and spasticity Place feeding tubes Release joint contractures ... the hip joint Injuries from falls Pressure sores Joint ... of the people who are affected by cerebral palsy) Social stigma

  7. Cerebral Palsy

    MedlinePlus

    ... Español (Spanish) Recommend on Facebook Tweet Share Compartir Cerebral palsy (CP) is a group of disorders that affect a ... ability to move and maintain balance and posture. CP is the most common motor disability in childhood. ...

  8. 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.

  9. 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.

  10. Children with cerebral palsy and periventricular white matter injury: does gestational age affect functional outcome?

    PubMed

    Harvey, Adrienne R; Randall, Melinda; Reid, Susan M; Lee, Katherine J; Imms, Christine; Rodda, Jillian; Eldridge, Beverley; Orsini, Francesca; Reddihough, Dinah

    2013-09-01

    This study aimed to determine differences in functional profiles and movement disorder patterns in children aged 4-12 years with cerebral palsy (CP) and periventricular white matter injury (PWMI) born >34 weeks gestation compared with those born earlier. Eligible children born between 1999 and 2006 were recruited through the Victorian CP register. Functional profiles were determined using the Gross Motor Function Classification System (GMFCS), Manual Abilities Classification System (MACS), Communication Function Classification System (CFCS), Functional Mobility Scale (FMS) and Bimanual Fine Motor Function (BFMF). Movement disorder and topography were classified using the Surveillance of Cerebral Palsy in Europe (SCPE) classification. 49 children born >34 weeks (65% males, mean age 8 y 9 mo [standard deviation (SD) 2 y 2 mo]) and 60 children born ≤ 34 weeks (62% males, mean age 8 y 2 mo [SD 2 y 2 mo]) were recruited. There was evidence of differences between the groups for the GMFCS (p=0.003), FMS 5, 50 and 500 (p=0.003, 0.002 and 0.012), MACS (p=0.04) and CFCS (p=0.035), with a greater number of children born ≤ 34 weeks more severely impaired compared with children born later. Children with CP and PWMI born >34 weeks gestation had milder limitations in gross motor function, mobility, manual ability and communication compared with those born earlier.

  11. Cerebral palsy.

    PubMed

    Graham, H Kerr; Rosenbaum, Peter; Paneth, Nigel; Dan, Bernard; Lin, Jean-Pierre; Damiano, Diane L; Becher, Jules G; Gaebler-Spira, Deborah; Colver, Allan; Reddihough, Dinah S; Crompton, Kylie E; Lieber, Richard L

    2016-01-07

    Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most countries, affecting about 1 in 500 neonates with an estimated prevalence of 17 million people worldwide. Cerebral palsy is not a disease entity in the traditional sense but a clinical description of children who share features of a non-progressive brain injury or lesion acquired during the antenatal, perinatal or early postnatal period. The clinical manifestations of cerebral palsy vary greatly in the type of movement disorder, the degree of functional ability and limitation and the affected parts of the body. There is currently no cure, but progress is being made in both the prevention and the amelioration of the brain injury. For example, administration of magnesium sulfate during premature labour and cooling of high-risk infants can reduce the rate and severity of cerebral palsy. Although the disorder affects individuals throughout their lifetime, most cerebral palsy research efforts and management strategies currently focus on the needs of children. Clinical management of children with cerebral palsy is directed towards maximizing function and participation in activities and minimizing the effects of the factors that can make the condition worse, such as epilepsy, feeding challenges, hip dislocation and scoliosis. These management strategies include enhancing neurological function during early development; managing medical co-morbidities, weakness and hypertonia; using rehabilitation technologies to enhance motor function; and preventing secondary musculoskeletal problems. Meeting the needs of people with cerebral palsy in resource-poor settings is particularly challenging.

  12. Cerebral palsy.

    PubMed

    Graham, H Kerr; Rosenbaum, Peter; Paneth, Nigel; Dan, Bernard; Lin, Jean-Pierre; Damiano, Diane L; Becher, Jules G; Gaebler-Spira, Deborah; Colver, Allan; Reddihough, Dinah S; Crompton, Kylie E; Lieber, Richard L

    2016-01-01

    Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most countries, affecting about 1 in 500 neonates with an estimated prevalence of 17 million people worldwide. Cerebral palsy is not a disease entity in the traditional sense but a clinical description of children who share features of a non-progressive brain injury or lesion acquired during the antenatal, perinatal or early postnatal period. The clinical manifestations of cerebral palsy vary greatly in the type of movement disorder, the degree of functional ability and limitation and the affected parts of the body. There is currently no cure, but progress is being made in both the prevention and the amelioration of the brain injury. For example, administration of magnesium sulfate during premature labour and cooling of high-risk infants can reduce the rate and severity of cerebral palsy. Although the disorder affects individuals throughout their lifetime, most cerebral palsy research efforts and management strategies currently focus on the needs of children. Clinical management of children with cerebral palsy is directed towards maximizing function and participation in activities and minimizing the effects of the factors that can make the condition worse, such as epilepsy, feeding challenges, hip dislocation and scoliosis. These management strategies include enhancing neurological function during early development; managing medical co-morbidities, weakness and hypertonia; using rehabilitation technologies to enhance motor function; and preventing secondary musculoskeletal problems. Meeting the needs of people with cerebral palsy in resource-poor settings is particularly challenging. PMID:27188686

  13. 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…

  14. Acute Physical Exercise Affects Cognitive Functioning in Children With Cerebral Palsy.

    PubMed

    Maltais, Désirée B; Gane, Claire; Dufour, Sophie-Krystale; Wyss, Dominik; Bouyer, Laurent J; McFadyen, Bradford J; Zabjek, Karl; Andrysek, Jan; Voisen, Julien I

    2016-05-01

    Little is known about the effects of acute exercise on the cognitive functioning of children with cerebral palsy (CP). Selected cognitive functions were thus measured using a pediatric version of the Stroop test before and after maximal, locomotor based aerobic exercise in 16 independently ambulatory children (8 children with CP), 6-15 years old. Intense exercise had: 1) a significant, large, positive effect on reaction time (RT) for the CP group (preexercise: 892 ± 56.5 ms vs. postexercise: 798 ± 45.6 ms, p < .002, d = 1.87) with a trend for a similar but smaller response for the typically developing (TD) group (preexercise: 855 ± 56.5 ms vs. postexercise: 822 ± 45.6 ms, p < .08, d = 0.59), and 2) a significant, medium, negative effect on the interference effect for the CP group (preexercise: 4.5 ± 2.5%RT vs. postexercise: 13 ± 2.9%RT, p < .04, d = 0.77) with no significant effect for the TD group (preexercise: 7.2 ± 2.5%RT vs. postexercise: 6.9 ± 2.9%RT, p > .4, d = 0.03). Response accuracy was high in both groups pre- and postexercise (>96%). In conclusion, intense exercise impacts cognitive functioning in children with CP, both by increasing processing speed and decreasing executive function. PMID:26502458

  15. Early life stress affects cerebral glucose metabolism in adult rhesus monkeys (Macaca mulatta).

    PubMed

    Parr, Lisa A; Boudreau, Matthew; Hecht, Erin; Winslow, James T; Nemeroff, Charles B; Sánchez, Mar M

    2012-01-01

    Early life stress (ELS) is a risk factor for anxiety, mood disorders and alterations in stress responses. Less is known about the long-term neurobiological impact of ELS. We used [(18)F]-fluorodeoxyglucose Positron Emission Tomography (FDG-PET) to assess neural responses to a moderate stress test in adult monkeys that experienced ELS as infants. Both groups of monkeys showed hypothalamic-pituitary-adrenal (HPA) axis stress-induced activations and cardiac arousal in response to the stressor. A whole brain analysis detected significantly greater regional cerebral glucose metabolism (rCGM) in superior temporal sulcus, putamen, thalamus, and inferotemporal cortex of ELS animals compared to controls. Region of interest (ROI) analyses performed in areas identified as vulnerable to ELS showed greater activity in the orbitofrontal cortex of ELS compared to control monkeys, but greater hippocampal activity in the control compared to ELS monkeys. Together, these results suggest hyperactivity in emotional and sensory processing regions of adult monkeys with ELS, and greater activity in stress-regulatory areas in the controls. Despite these neural responses, no group differences were detected in neuroendocrine, autonomic or behavioral responses, except for a trend towards increased stillness in the ELS monkeys. Together, these data suggest hypervigilance in the ELS monkeys in the absence of immediate danger. PMID:22682736

  16. Allometry and asymmetry in the dog brain: the right hemisphere is heavier regardless of paw preference.

    PubMed

    Tan, U; Calişkan, S

    1987-08-01

    The allometric relationship between brain and body size and asymmetry in the weight of the cerebral hemispheres were studied in dogs. A regression analysis of the brain versus body weight revealed an allometric relationship according to the power function Y = kXa. The right cerebral hemisphere was found to be significantly heavier than the left. This finding was not associated with paw preference. In accordance with previous studies, it was concluded that the right-biased asymmetry in the weight of the cerebral hemispheres may be a common feature of the mammalian brain. Functional implications of the results were discussed with regard to the right hemisphere specializations.

  17. Effect of chronic stress on behavior and cerebral oxidative metabolism in rats with high or low positive affect.

    PubMed

    Mällo, T; Matrov, D; Kõiv, K; Harro, J

    2009-12-15

    The 50 kHz ultrasonic vocalizations (USVs) in rats have been associated with positive affect and rewarding experience. We have previously reported that stable inter-individual differences exist in the expression of these USVs (chirps). We have examined the effect of four weeks of chronic variable stress on cerebral oxidative metabolism, and depression and anxiety related behavior in male and female high (HC) and low (LC) chirping rats. Significant differences in regional oxidative metabolic activity as measured by cytochrome c oxidase (COX) histochemistry were found between male and female rats: Females had lower oxidative metabolism in several brainstem areas such as dorsal and median raphe and pontine nucleus, some cortical areas, and reward-related forebrain regions such as striatum and nucleus accumbens, but higher oxidative metabolism in amygdala and related limbic regions. Chronic stress increased oxidative metabolism in several depression-related brain regions in male but not female LC-rats such as amygdala, hippocampus and anterior thalamus. No systematic behavioral effect of stress was evident in females. In LC males, stress elicited increased levels of 22-kHz USVs, earlier and more stable reduction of weight gain, persistently lower sucrose intake and preference, and higher levels of immobility in the forced swimming test. These behavioral changes, accompanied by increased oxidative metabolism in limbic brain regions, indicate greater vulnerability to stress of male LC-rats, and suggest that in males low inherent positive affectivity predisposes to anxiety and affective disorders.

  18. 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. PMID:18843371

  19. 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.

  20. Variables that affect the middle cerebral artery peak systolic velocity in fetuses with anemia and intrauterine growth restriction.

    PubMed

    Hanif, Farhan; Drennan, Kathrin; Mari, Giancarlo

    2007-09-01

    We have previously reported that the fetal middle cerebral artery (MCA) peak systolic velocity (PSV) increases in anemic fetuses and in fetuses with intrauterine growth restriction (IUGR). We hypothesized that the pathophysiology for the increased MCA PSV is different in anemic and IUGR fetuses. Thus the aim of this study was to determine the factor(s) among fetal umbilical vein blood pH, Po2, Pco2, and hemoglobin that might affect the MCA PSV in fetuses with anemia and IUGR. This study included two groups of fetuses. The first group included fetuses at risk for anemia because of red cell alloimmunization, whereas the second group included IUGR fetuses. For both groups of fetuses, we determined hemoglobin, umbilical vein blood gases -- at cordocentesis in anemic fetuses and immediately after cesarean delivery in IUGR fetuses -- and MCA PSV before cordocentesis, or before delivery. The relationship between MCA PSV and the hemoglobin, Po2, Pco2, and pH values for the anemic and the IUGR fetuses were assessed by regression analysis using multiples of the mean. There were 14 fetuses in the first group and 22 fetuses in the second group. In the first group, the only parameter that was related to MCA PSV was the fetal hemoglobin (R2 = 0.34; p < 0.05); in fetuses with IUGR, the Pco2 (R2 = 0.36; p < 0.01) and the PO2 (R2 = 0.30; p < 0.01) correlated well with the MCA PSV, whereas no relationship was found between the MCA PSV and the hemoglobin. The data indicate that the mechanism of high MCA PSV is different in anemic and nonanemic IUGR fetuses, and suggest that the process of cerebral autoregulation is present in the preterm IUGR fetus.

  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. 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…

  3. 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…

  4. 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

  5. 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

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

    PubMed

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

    2015-05-01

    [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.

  7. Effects of cerebral ischemia on neuronal hemoglobin

    PubMed Central

    He, Yangdong; Hua, Ya; Liu, Wenquan; Hu, Haitao; Keep, Richard F.; Xi, Guohua

    2009-01-01

    Summary The present study examined whether or not neuronal hemoglobin (Hb) is present in rats. It then examined whether cerebral ischemia or ischemic preconditioning (IPC) affects neuronal Hb levels in vivo and in vitro. In vivo, male Sprague-Dawley rats were subjected to either 15 minutes of transient middle cerebral artery occlusion with 24 hours of reperfusion, an IPC stimulus, or 24 hours of permanent middle cerebral artery occlusion (pMCAO), or IPC followed three days later by 24 hours of pMCAO. In vitro, primary cultured neurons were exposed to 2 hours of oxygen-glucose deprivation with 22 hours of reoxygenation. Results showed that Hb is widely expressed in rat cerebral neurons but not astrocytes. Hb expression was significantly upregulated in the ipsilateral caudate and the cortical core of the middle cerebral artery territory after IPC. Hb levels also increased in more penumbral cortex and the contralateral hemisphere 24 hours after pMCAO, but expression in the ipsilateral caudate and cortical core area were decreased. Ischemic preconditioning modified pMCAO-induced brain Hb changes. Neuronal Hb levels in vitro were increased by 2 hours of oxygen-glucose deprivation and 22 hours of reoxygenation. These results indicate that Hb is synthesized in neurons and can be upregulated by ischemia. PMID:19066615

  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. 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.

  10. 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. PMID:1095292

  11. Hemisphere-specific processes in letter matching.

    PubMed

    Kirsner, K

    1980-02-01

    Three experiments were designed to investigate outstanding questions concerning the effect of memory load variations on efficiency and coding processes in the left and right cerebral hemispheres. In Experiment 1 subjects were presented with one, two, or three target letters in uppercase or lowercase in central vision, followed by simultaneous bilateral probes requiring a name match response. Twenty young right-handed adults, 10 males and 10 females, acted as subjects. Two main features of the results were as follows: (a) The slope of the linear function relating mean reaction time (RT) and set size was 30% greater for right visual field (RVF)-left-hemisphere probe stimuli under both physical and name identity conditions, and (b) RT for RVF-left-hemisphere probes was greater when the probe was drawn from preterminal serial position in the target list. Experiments 2 and 3 examined the proposition that the results of Experiment 1 reflected asymmetric interference during list acquisition. The results showed that, first, the LVF-right-hemisphere advantage was eliminated or reversed under unilateral probe presentation conditions, and second, the LVF-right-hemisphere advantage for a single, preterminal serial position was insensitive to variations in the interitem interval. The results are thought to be inconsistent with the interference hypothesis. The general implications of the results for existing theories of hemisphere function are discussed.

  12. 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

  13. In your right mind: right hemisphere contributions to language processing and production.

    PubMed

    Lindell, Annukka K

    2006-09-01

    The verbal/nonverbal account of left and right hemisphere functionality is the prevailing dichotomy describing the cerebral lateralization of function. Yet the fact that the left hemisphere is the superior language processor does not necessarily imply that the right hemisphere is completely lacking linguistic ability. This paper reviews the growing body of research demonstrating that, far from being nonverbal, the right hemisphere has significant language processing strength. From prosodic and paralinguistic aspects of speech production, reception, and interpretation, to prelexical, lexical and postlexical components of visual word recognition; strong involvement of the right hemisphere is implicated. The evidence reviewed challenges the notion that language is solely a function of the "verbal" left hemisphere, indicating that the right cerebral hemisphere makes significant and meaningful contributions to normal language processing as well. PMID:17109238

  14. Metaphors and verbal creativity: the role of the right hemisphere.

    PubMed

    Gold, Rinat; Faust, Miriam; Ben-Artzi, Elisheva

    2012-01-01

    Ample research suggests that the right cerebral hemisphere plays a central role in verbal creativity as well as in novel metaphor comprehension. The aim of the present study was to directly examine the relation between verbal creativity and right hemisphere involvement during novel metaphor comprehension. Thus 30 healthy adults were asked to fill in the Hebrew version of the Remote Association Test to assess their level of creativity. In addition, reaction times and error rates were measured while these participants performed a semantic judgement task on two word expressions presented in a divided visual field paradigm. The word pairs comprised four types of semantic relations: novel metaphors, conventional metaphors, literal word pairs, and meaningless word pairs. Correlations were conducted to assess the relation between level of creativity and processing of the four pair types in the two cerebral hemispheres. The main finding was of a significant negative correlation between degree of creativity and reaction times to novel metaphor processing in the right hemisphere, thus supporting the involvement of this cerebral hemisphere in both tasks. Results are discussed in light of linguistic theories and recent neuroscientific evidence regarding relative hemispheric involvement during semantic processing.

  15. Hemispheric specialization for language.

    PubMed

    Josse, Goulven; Tzourio-Mazoyer, Nathalie

    2004-01-01

    Hemispheric specialization for language is one of the most robust findings of cognitive neuroscience. In this review, we first present the main hypotheses about the origins of this important aspect of brain organization. These theories are based in part on the main approaches to hemispheric specialization: studies of aphasia, anatomical asymmetries and, nowadays, neuroimaging. All these approaches uncovered a large inter-individual variability which became the bulk of research on hemispheric specialization. This is why, in a second part of the review, we present the main facts about inter-individual variability, trying to relate findings to the theories presented in the first part. This review focuses on neuroimaging as it has recently given important results, thanks to investigations of both anatomical and functional asymmetries in healthy subjects. Such investigations have confirmed that left-handers, especially "familial left-handers", are more likely to have an atypical pattern of hemispheric specialization for language. Differences between men and women seem less evident although a less marked hemispheric specialization for language was depicted in women. As for the supposed relationship between anatomical and functional asymmetries, it has been shown that the size of the left (not the right) planum temporale could explain part of the variability of left hemispheric specialization for language comprehension. Taken as a whole, findings seem to vary with language tasks and brain regions, therefore showing that hemispheric specialization for language is multi-dimensional. This is not accounted for in the existing models of hemispheric specialization. PMID:14739000

  16. Cerebral Palsy

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Cerebral Palsy KidsHealth > For Teens > Cerebral Palsy Print A A ... do just what everyone else does. What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder of the ...

  17. Midline-shift corresponds to the amount of brain edema early after hemispheric stroke--an MRI study in rats.

    PubMed

    Walberer, Maureen; Blaes, Franz; Stolz, Erwin; Müller, Clemens; Schoenburg, Markus; Tschernatsch, Marlene; Bachmann, Georg; Gerriets, Tibo

    2007-04-01

    Vasogenic brain edema formation is a serious complication in hemispheric stroke. Its space-occupying effect can lead to midline-shift (MLS), cerebral herniation, and death. Clinical studies indicate that quantification of MLS can predict cerebral herniation and subsequent death at early time-points, even before clinical deterioration becomes apparent. The present experimental study was designed to determine the relation between MLS, absolute edema volume, lesion size, and clinical findings in a rat stroke model. Middle cerebral artery-occlusion was performed in 24 rats using the suture technique. Clinical evaluation and magnetic resonance imaging (MRI) (Bruker PharmaScan 7.0T) was performed 24 hours later. Lesion volume, the volume-increase within the affected hemisphere (%HEV), and MLS were quantified on T2-weighted images. The absolute increase of hemispheric water content (DeltaH2O) was determined in a subgroup using the wet-dry method (n=12). MLS correlated significantly with the total amount of brain edema (magnetic resonance imaging study: r=0.82; P<0.01; wet-dry analysis r=0.80; P<0.01). MLS correlated only moderately with T2-lesion volume (r=0.55; P<0.01). No significant correlation could be detected between MLS and clinical scores (r=0.26; P>0.05). MLS thus quantitatively reflects the amount of vasogenic brain edema within the affected hemisphere at early time-points. MLS quantification can be regarded as an easily assessable and valid global quantitative parameter for brain edema and thus might facilitate the surgical and nonsurgical management of edema in acute stroke patients. PMID:17413996

  18. 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.

  19. 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

  20. Recovering two languages with the right hemisphere.

    PubMed

    Marini, Andrea; Galetto, Valentina; Tatu, Karina; Duca, Sergio; Geminiani, Giuliano; Sacco, Katiuscia; Zettin, Marina

    2016-08-01

    Converging evidence suggests that the right hemisphere (RH) plays an important role in language recovery from aphasia after a left hemisphere (LH) lesion. In this longitudinal study we describe the neurological, cognitive, and linguistic profile of A.C., a bilingual who, after a severe traumatic brain injury, developed a form of fluent aphasia that affected his two languages (i.e., Romanian and Italian). The trauma-induced parenchymal atrophy led to an exceptional ventricular dilation that, gradually, affected the whole left hemisphere. A.C. is now recovering both languages relying only on his right hemisphere. An fMRI experiment employing a bilingual covert verb generation task documented the involvement of the right middle temporal gyrus in processes of lexical selection and access. This case supports the hypothesis that the RH plays a role in language recovery from aphasia when the LH has suffered massive lesions. PMID:27289209

  1. 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

  2. Resting-state cerebellar-cerebral networks are differently affected in first-episode, drug-naive schizophrenia patients and unaffected siblings.

    PubMed

    Guo, Wenbin; Liu, Feng; Chen, Jindong; Wu, Renrong; Zhang, Zhikun; Yu, Miaoyu; Xiao, Changqing; Zhao, Jingping

    2015-11-26

    Dysconnectivity hypothesis posits that schizophrenia is a disorder with dysconnectivity of the cortico-cerebellar-thalamic-cortical circuit (CCTCC). However, it remains unclear to the changes of the cerebral connectivity with the cerebellum in schizophrenia patients and unaffected siblings. Forty-nine patients with first-episode, drug-naive schizophrenia patients, 46 unaffected siblings of schizophrenia patients and 46 healthy controls participated in the study. Seed-based resting-state functional connectivity approach was employed to analyze the data. Compared with the controls, the patients and the siblings share increased default-mode network (DMN) seed - right Crus II connectivity. The patients have decreased right dorsal attention network (DAN) seed - bilateral cerebellum 4,5 connectivity relative to the controls. By contrast, the siblings exhibit increased FC between the right DAN seed and the right cerebellum 6 and right cerebellum 4,5 compared to the controls. No other abnormal connectivities (executive control network and salience network) are observed in the patients/siblings relative to the controls. There are no correlations between abnormal cerebellar-cerebral connectivities and clinical variables. Cerebellar-cerebral connectivity of brain networks within the cerebellum are differently affected in first-episode, drug-naive schizophrenia patients and unaffected siblings. Increased DMN connectivity with the cerebellum may serve as potential endophenotype for schizophrenia.

  3. Resting-state cerebellar-cerebral networks are differently affected in first-episode, drug-naive schizophrenia patients and unaffected siblings

    PubMed Central

    Guo, Wenbin; Liu, Feng; Chen, Jindong; Wu, Renrong; Zhang, Zhikun; Yu, Miaoyu; Xiao, Changqing; Zhao, Jingping

    2015-01-01

    Dysconnectivity hypothesis posits that schizophrenia is a disorder with dysconnectivity of the cortico-cerebellar-thalamic-cortical circuit (CCTCC). However, it remains unclear to the changes of the cerebral connectivity with the cerebellum in schizophrenia patients and unaffected siblings. Forty-nine patients with first-episode, drug-naive schizophrenia patients, 46 unaffected siblings of schizophrenia patients and 46 healthy controls participated in the study. Seed-based resting-state functional connectivity approach was employed to analyze the data. Compared with the controls, the patients and the siblings share increased default-mode network (DMN) seed – right Crus II connectivity. The patients have decreased right dorsal attention network (DAN) seed – bilateral cerebellum 4,5 connectivity relative to the controls. By contrast, the siblings exhibit increased FC between the right DAN seed and the right cerebellum 6 and right cerebellum 4,5 compared to the controls. No other abnormal connectivities (executive control network and salience network) are observed in the patients/siblings relative to the controls. There are no correlations between abnormal cerebellar-cerebral connectivities and clinical variables. Cerebellar-cerebral connectivity of brain networks within the cerebellum are differently affected in first-episode, drug-naive schizophrenia patients and unaffected siblings. Increased DMN connectivity with the cerebellum may serve as potential endophenotype for schizophrenia. PMID:26608842

  4. 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

  5. Hemisphere Asymmetry of Response to Pharmacologic Treatment in an Alzheimer's Disease Mouse Model.

    PubMed

    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.

  6. Hemisphere Asymmetry of Response to Pharmacologic Treatment in an Alzheimer's Disease Mouse Model.

    PubMed

    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

  7. 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…

  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. 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…

  10. 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…

  11. 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.

  12. 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.

  13. 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…

  14. 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…

  15. 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…

  16. Hemispheric Assymeries in Auroral Precipitation

    NASA Astrophysics Data System (ADS)

    Mende, S. B.

    2014-12-01

    It is widely accepted that the space weather related electrodynamic forcing of the geospace environment acts through the high geomagnetic latitude regions. At high latitudes inter-hemispheric asymmetries are largely due to the differences in solar illumination, the direction of the solar wind and interplanetary magnetic field components and to a lesser extent, due to differences between the two hemispheric internal fields. So far most research regarding interhemispheric differences concentrated on learning about the basic magnetosphere-ionosphere coupling mechanisms. It has been well established that sunlit conditions affect the energy flux of auroral precipitation resulting from the reduction in the mean energy of the auroral electrons in the sunlit summer hemisphere. This can be explained by the partial shorting out of the particle accelerating fields by the sunlight induced conductivity. It has also been found that sunlit conditions reduce the particle fluxes and therefore the associated field aligned currents. Unless the precipitation-induced conductivities overwhelm the sunlit component of conductivity, this would imply that the magnetospheric current generator responds to the ionospheric load in a highly non-linear manner. Interhemispheric currents may also play an important role that has not been fully explored. Interhemispheric asymmetries in substorm morphology have been explored critically because conjugacy implies that substorms have a common source at equatorial latitudes. In some cases the lack of conjugacy of substorms could be explained by considering the magnitude and direction of the IMF.

  17. [Delayed development of hemispheric dominance accompanied by a rare form of retarded language development].

    PubMed

    Brunner, M; Wirth, G

    1986-04-01

    A severe and unusual form of retarded speech development in an eight-year old boy is analyzed as "right-hemispheric speech" against the background of neuropsychological theories on the specialisation of the cerebral hemispheres and considered in connection with the development of hemispheric dominance. A plan for therapy and teacher counselling is derived from this analysis. The influence of this retarded speech development on the acquisition of reading and writing is also touched upon.

  18. 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

  19. 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

  20. Cerebral blood flow velocity in two patients with neonatal cerebral infarction.

    PubMed

    Nishimaki, S; Seki, K; Yokota, S

    2001-04-01

    Cerebral blood flow velocity was measured in the middle cerebral artery of two patients who exhibited unilateral neonatal cerebral infarction during the neonatal period. Doppler studies demonstrated increases in cerebral blood flow velocity but decreases in the resistance index on the affected side of the middle cerebral artery in the neonate who developed hemiplegia with cystic encephalomalacia, although the neonate with normal neurologic outcome exhibited symmetric cerebral blood flow velocity and resistance index. The asymmetry in cerebral blood flow velocity measurements of both middle cerebral arteries may be useful to evaluate the severity of brain damage and predict the neurodevelopmental prognosis of unilateral neonatal cerebral infarction. PMID:11377112

  1. Cerebral Hypoxia

    MedlinePlus

    ... Enhancing Diversity Find People About NINDS NINDS Cerebral Hypoxia Information Page Synonym(s): Hypoxia, Anoxia Table of Contents ( ... Trials Organizations Publicaciones en Español What is Cerebral Hypoxia? Cerebral hypoxia refers to a condition in which ...

  2. Spontaneous pre-existing hypoxia does not affect brain damage after global cerebral ischaemia in late-gestation fetal sheep.

    PubMed

    Davidson, Joanne O; Yuill, Caroline A; Wassink, Guido; Bennet, Laura; Gunn, Alistair J

    2015-01-01

    There is considerable evidence that a mild, non-injurious insult can protect (precondition) against a subsequent injurious insult. Typically, protection is seen when the gap between insults is several days to a week. However, the effect of mild but persistent hypoxia is unknown. In this study we examined the hypothesis that mild pre-existing hypoxia (PaO2<17 mm Hg) would reduce neural injury in chronically instrumented late-gestation (0.85 gestation) fetal sheep exposed to 30 min of global cerebral ischaemia induced by bilateral carotid artery occlusion (normoxia: n=9 vs. pre-existing hypoxia: n=9) or normoxia plus sham ischaemia (sham controls: n=9). Histopathology was assessed after 7 days of recovery. Fetuses with pre-existing hypoxia had lower PaO2 values (16.1±0.6 vs. 26.0±1.1 mm Hg) and were lighter at post-mortem (4,033±412 vs. 5,261±238 g) compared to normoxic fetuses. Cerebral ischaemia was associated with secondary cortical oedema and seizures, reduced final EEG power, loss of sleep state cycling, and significant loss of neurons and oligodendrocytes, with no significant effect of pre-existing hypoxia. Pre-existing hypoxia was associated with a significantly attenuated rise in mean arterial pressure between 18 and 36 h and slower resolution of cortical oedema between 96 and 150 h after ischaemia. These data suggest that chronic hypoxia is not associated with a significant preconditioning effect.

  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. PMID:26426534

  4. 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)

  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. 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. PMID:27566000

  7. 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…

  8. 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.

  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. PMID:25462474

  10. Perinatal cortical infarction within middle cerebral artery trunks

    PubMed Central

    Govaert, P.; Matthys, E.; Zecic, A.; Roelens, F.; Oostra, A.; Vanzieleghem, B.

    2000-01-01

    AIM—To define neonatal pial middle cerebral artery infarction.
METHODS—A retrospective study was made of neonates in whom focal arterial infarction had been detected ultrasonographically. A detailed study was made of cortical middle cerebral artery infarction subtypes.
RESULTS—Forty infarctions, with the exception of those in a posterior cerebral artery, were detected ultrasonographically over a period of 10 years. Most were confirmed by computed tomography or magnetic resonance imaging. Factor V Leiden heterozygosity was documented in three. The onset was probably antepartum in three, and associated with fetal distress before labour in one. There were 19 cases of cortical middle cerebral artery stroke. The truncal type (n=13) was more common than complete (n = 5) middle cerebral artery infarction. Of six infarcts in the anterior trunk, four were in term infants and five affected the right hemisphere. Clinical seizures were part of the anterior truncal presentation in three. One of these infants, with involvement of the primary motor area, developed a severe motor hemisyndrome. The Bayley Mental Developmental Index was above 80 in all of three infants tested with anterior truncal infarction. Of seven patients with posterior truncal infarction, six were at or near term. Six of these lesions were left sided. Clinical seizures were observed in three. A mild motor hemisyndrome developed in at least three of these infants due to involvement of parieto-temporal non-primary cortex.
CONCLUSIONS—Inability to differentiate between truncal and complete middle cerebral artery stroke is one of the explanations for the reported different outcomes. Severe motor hemisyndrome can be predicted from neonatal ultrasonography on the basis of primary motor cortex involvement. Clinical seizures were recognised in less than half of the patients with truncal infarction; left sided presentation was present in the posterior, but not the anterior truncal type of infarction

  11. Music and cerebral hemodynamics.

    PubMed

    Marinoni, M; Grassi, E; Latorraca, S; Caruso, A; Sorbi, S

    2000-09-01

    Previous studies performed by positron emission tomography and Transcranial Doppler (TCD) found a different cerebral activation during musical stimuli in musicians compared to non-musicians. The aim of our study is to evaluate by means of TCD, possible different pattern of cerebral activation during the performance of different musical tasks in musicians, non-musicians and lyrical singers. Our findings show a left hemispheric activation in musicians and a right one in non-musicians. Preliminary data on lyrical singers' activation patterns need further confirmation with a larger population. These data could be related to a different approach to music listening in musicians (analytical) and non-musicians who are supposed to have an emotional approach to music. PMID:10942664

  12. 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…

  13. 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…

  14. Prolonged Antegrade Cerebral Perfusion via Right Axillary Artery (≥60 min) Does Not Affect Early Outcomes in a Repair of Type A Acute Aortic Dissection

    PubMed Central

    Saji, Yoshiaki; Kanemitsu, Hideo; Koyama, Tadaaki

    2015-01-01

    Purpose: We aim to investigate whether the duration of antegrade cerebral perfusion (ACP) via right axillary artery with an 8-mm prosthetic graft affects early outcomes in a repair of type A acute aortic dissection (AAD). Methods: Over the 24 months from April 2010, a repair of AAD under ACP via the right axillary artery and mild hypothermic circulatory arrest (rectum temperature, 28–30°C) was performed in 34 patients. Mean age was 64.5 ± 13.7 years of age. Preoperative shock status was in three due to cardiac tamponade. Organ malperfusion occurred in 11 patients preoperatively. Mean follow-up period was 9.6 ± 8.4 months and follow-up rate was 100%. Results: Hospital mortality rate was 8.8%. No newly required hemodialysis and new onset of temporary or permanent neurologic deficits were present in survivors. There were no statistically significant differences of mortality rate, new onset of permanent or temporary neurologic deficits and distal organ dysfunction between ACP duration <60 min and ≥60 min. The 12-month survival was 84.4% ± 6.4%. And, freedom from aorta-related events at 12 and 18 months were 100% ± 0.0% and 88.9% ± 10.5%, respectively. Conclusions: The duration of ACP via right axillary artery does not affect early outcomes following a repair of AAD. PMID:26062579

  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. Cerebral Palsy

    MedlinePlus

    ... Got Homework? Here's Help White House Lunch Recipes 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 ...

  17. Cerebral Palsy

    MedlinePlus

    ... Loss > Birth defects & other health conditions > Cerebral palsy Cerebral palsy E-mail to a friend Please fill in ... movement problems a child has. What is spastic CP? Spastic means tight or stiff muscles, or muscles ...

  18. Cerebral malaria.

    PubMed

    Postels, Douglas G; Birbeck, Gretchen L

    2013-01-01

    Malaria, the most significant parasitic disease of man, kills approximately one million people per year. Half of these deaths occur in those with cerebral malaria (CM). The World Health Organization (WHO) defines CM as an otherwise unexplained coma in a patient with malarial parasitemia. Worldwide, CM occurs primarily in African children and Asian adults, with the vast majority (greater than 90%) of cases occurring in children 5 years old or younger in sub-Saharan Africa. The pathophysiology of the disease is complex and involves infected erythrocyte sequestration, cerebral inflammation, and breakdown of the blood-brain barrier. A recently characterized malarial retinopathy is visual evidence of Plasmodium falciparum's pathophysiological processes occurring in the affected patient. Treatment consists of supportive care and antimalarial administration. Thus far, adjuvant therapies have not been shown to improve mortality rates or neurological outcomes in children with CM. For those who survive CM, residual neurological abnormalities are common. Epilepsy, cognitive impairment, behavioral disorders, and gross neurological deficits which include motor, sensory, and language impairments are frequent sequelae. Primary prevention strategies, including bed nets, vaccine development, and chemoprophylaxis, are in varied states of development and implementation. Continuing efforts to find successful primary prevention options and strategies to decrease neurological sequelae are needed. PMID:23829902

  19. 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.

  20. Cerebral Palsy

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS NINDS Cerebral Palsy Information Page Clinical Trials Trial of Erythropoietin Neuroprotection ... en Español Additional resources from MedlinePlus What is Cerebral Palsy? The term cerebral palsy refers to a group ...

  1. Cerebral Aneurysms

    MedlinePlus

    ... Enhancing Diversity Find People About NINDS NINDS Cerebral Aneurysms Information Page Synonym(s): Aneurysm, Brain Aneurysm Condensed from ... Español Additional resources from MedlinePlus What is Cerebral Aneurysms? A cerebral aneurysm is a weak or thin ...

  2. Telencephalic Flexure and Malformations of the Lateral Cerebral (Sylvian) Fissure.

    PubMed

    Sarnat, Harvey B; Flores-Sarnat, Laura

    2016-10-01

    After sagittal division of the prosencephalon at 4.5 weeks of gestation, the early fetal cerebral hemisphere bends or rotates posteroventrally from seven weeks of gestation. The posterior pole of the telencephalon thus becomes not the occipital but the temporal lobe as the telencephalic flexure forms the operculum and finally the lateral cerebral or Sylvian fissure. The ventral part is infolded to become the insula. The frontal and temporal lips of the Sylvian fissure, as well as the insula, all derive from the ventral margin of the primitive telencephalon, hence may be influenced by genetic mutations with a ventrodorsal gradient of expression. The telencephalic flexure also contributes to a shift of the hippocampus from a dorsal to a ventral position, the early rostral pole of the hippocampus becoming caudal and dorsal becoming ventral. The occipital horn is the most recent recess of the lateral ventricle, hence most vulnerable to anatomic variations that affect the calcarine fissure. Many major malformations include lack of telencephalic flexure (holoprosencephaly, extreme micrencephaly) or dysplastic Sylvian fissure (lissencephalies, hemimegalencephaly, schizencephaly). Although fissures and sulci are genetically programmed, mechanical forces of growth and volume expansion are proposed to be mainly extrinsic (including ventricles) for fissures and intrinsic for sulci. In fetal hydrocephalus, the telencephalic flexure is less affected because ventricular dilatation occurs later in gestation. Flexures can be detected prenatally by ultrasound and fetal magnetic resonance imaging and should be described neuropathologically in cerebral malformations. PMID:27590993

  3. [Pathogenesis of infantile cerebral palsy].

    PubMed

    Semenova, K A

    1980-01-01

    Some causes of the pathological activity of postural reflexes and other motor disturbances underlying the clinical picture of infantile cerebral paralysis are considered. It is shown that disturbed metabolism of corticosteroids observed in that disease, as well as impaired functional activity of T lymphocytes promote the development of both inflammatory and neuroimmune processes in the brain, mainly in large hemispheres--and this may be one of the causes of the pathological postural activity. PMID:6969015

  4. 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.

  5. 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.

  6. Right Hemisphere and Left Hemisphere: Pedagogical Implications for CSL Reading.

    ERIC Educational Resources Information Center

    Mickel, Stanley L.

    Students can be taught to read Chinese more efficiently and accurately by using the specific capabilities of the right and left hemispheres of the brain. The right hemisphere is the site of image and pattern recognition, and students can be taught to use those capacities to process individual characters efficiently by watching for the element of…

  7. 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. PMID:12745626

  8. 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.

  9. 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.

  10. Hemispheric representation of the central retina of commissurotomized subjects.

    PubMed

    Sugishita, M; Hamilton, C R; Sakuma, I; Hemmi, I

    1994-04-01

    It is controversial whether a stimulus projected within 1 to 3 degrees from the boundary between the right and left hemiretina is transmitted to only one cerebral hemisphere or to both cerebral hemispheres. In order to resolve this issue, letter- and word-stimuli were presented for 200 msec with a new type of tachistoscope, called the fundus tachistoscope, in and about the central retina, (i.e. fovea, 1.2 degrees in horizontal diameter) of the right eyes of two commissurotomized subjects (N.G. and A.A.). During stimulus presentation the subjects were attempting to fixate a fixation target. The fundus tachistoscope combined with image analysis of the fundus enables us to measure the position of the stimulus on the retina, relative to the foveal center, as well as whether or not the eye moved during stimulus presentation. The results indicate that the region of the right (temporal) hemiretina represented by both hemispheres in letter processing, if it exists, was estimated as less than 0.6 degrees from the foveal center. The two subjects frequently (27% in N.G. and 46% in A.A.) fixated the fixation target eccentrically, i.e. with a retinal point other than the foveal center, during fixation, namely stimulus presentation. Their eccentric fixations were small with magnitude almost all falling between 1.35 degrees right and 1.25 degrees left of the foveal center. It is therefore recommended that letter-stimuli be presented at least 2.0 degrees from the foveal center in ordinary tachistoscopic studies of cerebral hemispheric differences. Eye movements, which varied in 0.11 degrees and 1.43 degrees horizontally, occurred in about 8% of all the trials during fixation. On the average of the two subjects, the eye movements caused or worsened eccentric fixation in only about one third of the trials, and corrected eccentric fixation in about two thirds of the trials.

  11. 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)

  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. 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

  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. 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.

  16. Cerebral hemodynamics in patients with moyamoya disease. A study of regional cerebral blood flow by the /sup 133/Xe inhalation method

    SciTech Connect

    Takeuchi, S.; Tanaka, R.; Ishii, R.; Tsuchida, T.; Kobayashi, K.; Arai, H.

    1985-05-01

    Regional cerebral blood flow was measured by the /sup 133/Xe inhalation method in 20 young patients with moyamoya disease and five young healthy volunteers. Most patients showed low values of mean hemispheric blood flow in both hemispheres. Regional cerebral blood flow was at a low value in the upper frontal region and at an almost average value in the posterotemporal and occipital regions, which was different from the ''hyperfrontal'' pattern in healthy volunteers. Regional cerebral blood flow was reduced evenly by hyperventilation. By 5% CO/sub 2/ inhalation, regional cerebral blood flow was increased in the temporooccipital regions and was nearly unchanged or decreased in the frontal region.

  17. Rehabilitation for cognitive-communication disorders in right hemisphere brain damage.

    PubMed

    Tompkins, Connie A

    2012-01-01

    Although the left hemisphere of the brain has long been linked with language, the right cerebral hemisphere also contributes importantly to cognitive operations that underlie language processing and communicative performance. Adults with right hemisphere damage (RHD) typically do not have aphasia, but they often have communication disorders that may have a substantial impact on their social functioning. After a brief summary of communicative and cognitive characteristics of RHD in adults and of extant theoretical accounts of common communicative difficulties, this article discusses rehabilitation issues, approaches, evidence, and needs.

  18. 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

  19. Moon - Western Hemisphere

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This image of the western hemisphere of the Moon was taken through a green filter by the Galileo spacecraft at 9:35 a.m. PST Dec. 9 at a range of about 350,000 miles. In the center is the Orientale Basin, 600 miles in diameter, formed about 3.8 billion years ago by the impact of an asteroid-size body. Orientale's dark center is a small mare. To the right is the lunar nearside with the great, dark Oceanus Procellarum above and the small, circular, dark Mare Humorum below. Maria are broad plains formed mostly over 3 billion years ago as vast basaltic lava flows. To the left is the lunar far side with fewer maria but, at lower left, the South-Pole-Aitken basin, about 1200 miles in diameter, which resembles Orientale but is much older and more weathered and battered by cratering. The intervening cratered highlands of both sides, as well as the maria, are dotted with bright, young craters. This image was 'reprojected' so as to center the Orientale Basin, and was filtered to enhance the visibility of small features. The digital image processing was done by DLR, the German Aerospace Research Establishment near Munich, an international collaborator in the Galileo mission.

  20. Callisto's Southern Hemisphere

    NASA Technical Reports Server (NTRS)

    1997-01-01

    These views of Callisto's southern hemisphere were taken by the Near Infrared Mapping Spectrometer just after closest approach in orbit G8 on May 6, 1997. These false color images show surface compositional differences, red = more ice, blue = less ice.

    The upper left view contains Buri, a crater with a diameter of about 60 km. In the infrared spectrum, Buri and the rays that extend from the crater have high abundance of water ice compared to the surrounding region. The center view, a large (200 km or 120 mile diameter) unnamed impact crater with a distinct ring or circle around it reveals a complex mix of ice and non-ice materials. This is possibly due to impact excavation of the ice-rich subsurface which suggests that the darker material is just a thin surface covering caused by impact debris or a lag deposit from which the ice has evaporated away. The infrared data shows spectral signatures for both sulfur and carbon as two potential materials which could play a part in the complicated make-up of Callisto's surface.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    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.

  1. Detonation in TATB Hemispheres

    SciTech Connect

    Druce, B; Souers, P C; Chow, C; Roeske, F; Vitello, P; Hrousis, C

    2004-03-17

    Streak camera breakout and Fabry-Perot interferometer data have been taken on the outer surface of 1.80 g/cm{sup 3} TATB hemispherical boosters initiated by slapper detonators at three temperatures. The slapper causes breakout to occur at 54{sup o} at ambient temperatures and 42{sup o} at -54 C, where the axis of rotation is 0{sup o}. The Fabry velocities may be associated with pressures, and these decrease for large timing delays in breakout seen at the colder temperatures. At room temperature, the Fabry pressures appear constant at all angles. Both fresh and decade-old explosive are tested and no difference is seen. The problem has been modeled with reactive flow. Adjustment of the JWL for temperature makes little difference, but cooling to -54 C decreases the rate constant by 1/6th. The problem was run both at constant density and with density differences using two different codes. The ambient code results show that a density difference is probably there but it cannot be quantified.

  2. 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…

  3. 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

  4. 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

  5. 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.

  6. [Paracoccidioidomycosis in cerebral hemisphere and brainstem: case report].

    PubMed

    Leal Filho, Manoel Baldoino; Borges, Guilherme; da Silva, Raimundo Gerônimo; de Almeida Xavier Aguiar, Aline; de Almeida, Bruno Ribeiro; da Cunha E Silva Vieira, Marcelo Adriano; Pinheiro, Luciana Maria Ribeiro

    2006-09-01

    We report on a 36 years-old man that had been at the Amazon forest four years before. Six months before the admission he had developed a progressive quadriparesis, gait ataxia, dysphagia, dysarthria, difficulty in breathing and hiccup. The gadolinium-enhanced T1-weighted MRI showed a lesion into the right parietoccipital area and another into the medulla, that was the largest. There was any evidence of tuberculosis or AIDS. The patient was submitted to microsurgical approach to the medulla. Pathological examination revealed paracoccidioidomycosis. Treatment with anphotericin B till 2100 mg was administered followed by sulfamethoxazole-trimetoprim for three months plus physical therapy. The patient went back to his activities six months after the end of the treatment. Comments are presented about the participation of the immunological system and of the cytokines (interleukines).

  7. 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…

  8. Developmental dyslexia and widespread activation across the cerebellar hemispheres.

    PubMed

    Baillieux, Hanne; Vandervliet, Everhard J M; Manto, Mario; Parizel, Paul M; De Deyn, Peter P; Mariën, Peter

    2009-02-01

    Developmental dyslexia is the most common learning disability in school-aged children with an estimated incidence of five to ten percent. The cause and pathophysiological substrate of this developmental disorder is unclear. Recently, a possible involvement of the cerebellum in the pathogenesis of dyslexia has been postulated. In this study, 15 dyslexic children and 7 age-matched control subjects were investigated by means of functional neuroimaging (fMRI) using a noun-verb association paradigm. Comparison of activation patterns between dyslexic and control subjects revealed distinct and significant differences in cerebral and cerebellar activation. Control subjects showed bilaterally well-defined and focal activation patterns in the frontal and parietal lobes and the posterior regions of the cerebellar hemispheres. The dyslexic children, however, presented widespread and diffuse activations on the cerebral and cerebellar level. Cerebral activations were found in frontal, parietal, temporal and occipital regions. Activations in the cerebellum were found predominantly in the cerebellar cortex, including Crus I, Crus II, hemispheric lobule VI, VII and vermal lobules I, II, III, IV and VII. This preliminary study is the first to reveal a significant difference in cerebellar functioning between dyslexic children and controls during a semantic association task. As a result, we propose a new hypothesis regarding the pathophysiological mechanisms of developmental dyslexia. Given the sites of activation in the cerebellum in the dyslexic group, a defect of the intra-cerebellar distribution of activity is suspected, suggesting a disorder of the processing or transfer of information within the cerebellar cortex. PMID:18986695

  9. Cerebral palsy.

    PubMed

    Wimalasundera, Neil; Stevenson, Valerie L

    2016-06-01

    Cerebral palsy has always been known as a disorder of movement and posture resulting from a non-progressive injury to the developing brain; however, more recent definitions allow clinicians to appreciate more than just the movement disorder. Accurate classification of cerebral palsy into distribution, motor type and functional level has advanced research. It also facilitates appropriate targeting of interventions to functional level and more accurate prognosis prediction. The prevalence of cerebral palsy remains fairly static at 2-3 per 1000 live births but there have been some changes in trends for specific causal groups. Interventions for cerebral palsy have historically been medical and physically focused, often with limited evidence to support their efficacy. The use of more appropriate outcome measures encompassing quality of life and participation is helping to deliver treatments which are more meaningful for people with cerebral palsy and their carers.

  10. Technetium-99m HM-PAO-SPECT study of regional cerebral perfusion in early Alzheimer's disease

    SciTech Connect

    Perani, D.; Di Piero, V.; Vallar, G.; Cappa, S.; Messa, C.; Bottini, G.; Berti, A.; Passafiume, D.; Scarlato, G.; Gerundini, P.

    1988-09-01

    Regional cerebral perfusion was evaluated by single photon emission computed tomography (SPECT) using technetium-99m hexamethylpropyleneamine oxime ((/sup 99m/Tc)HM-PAO) in sixteen patients with Alzheimer's disease (AD) in early clinical phase and in 16 healthy elderly controls. In all patients transmission computed tomography (TCT) and/or magnetic resonance imaging (MRI) did not show focal brain abnormalities. Relative to normal subjects, AD patients showed significant reductions in cortical/cerebellar activity ratio: cortical perfusion was globally depressed with the largest reductions in frontal and posterior temporo-parietal cortices. Asymmetries of relative perfusion between cerebral hemispheres were also demonstrated when language was affected or visuospatial functions were unevenly impaired. In patients with early AD, SPECT provides functional information to be compared with clinical and psychometric data.

  11. Cerebral morphology and functional sparing after prenatal frontal cortex lesions in rats.

    PubMed

    Kolb, B; Cioe, J; Muirhead, D

    1998-03-01

    Rats were given suction lesions of the presumptive frontal cortex on embryonic day 18 (E18) and subsequently tested, as adults, on tests of spatial navigation (Morris water task, radial arm maze), motor tasks (Whishaw reaching task, beam walking), and locomotor activity. Frontal cortical lesions at E18 affected cerebral morphogenesis, producing unusual morphological structures including abnormal patches of neurons in the cortex and white matter as well as neuronal bridges between the hemispheres. A small sample of E18 operates also had hydrocephaly. The animals with E18 lesions without hydrocephalus were behaviorally indistinguishable from littermate controls. The results demonstrate that animals with focal lesions of the presumptive frontal cortex have gross abnormalities in cerebral morphology but the lesions leave the functions normally subserved by the frontal cortex in adult rats unaffected. The results are discussed in the context of a hypothesis regarding the optimal times for functional recovery from cortical injury. PMID:9578447

  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. 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)

  14. 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.

  15. 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.

  16. 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)

  17. An investigation of the factors affecting handwriting articulation of school aged children with cerebral palsy based on the international classification of functioning, disability and health.

    PubMed

    Kim, Hee Young

    2016-01-01

    [Purpose] This study was designed to identify factors influencing handwriting articulation based on the international classification of functioning, disability and health (ICF) and to recommend effective evaluation and intervention strategies to improve the handwriting of children with cerebral palsy. [Subjects] The subjects were 96 elementary school children with cerebral palsy and the study was conducted from 04/07/2011 to 29/08/2011. [Methods] Factors related to handwriting articulation were investigated based on the ICF model. [Results] Wrist lateral deviation, upper-extremity speed of body function and education of personal factor were significantly associated with handwriting articulation. [Conclusion] Efforts to manage and improve the handwriting articulation of children with cerebral palsy should focus on wrist lateral deviation, upper-extremity speed, and education.

  18. An investigation of the factors affecting handwriting articulation of school aged children with cerebral palsy based on the international classification of functioning, disability and health

    PubMed Central

    Kim, Hee Young

    2016-01-01

    [Purpose] This study was designed to identify factors influencing handwriting articulation based on the international classification of functioning, disability and health (ICF) and to recommend effective evaluation and intervention strategies to improve the handwriting of children with cerebral palsy. [Subjects] The subjects were 96 elementary school children with cerebral palsy and the study was conducted from 04/07/2011 to 29/08/2011. [Methods] Factors related to handwriting articulation were investigated based on the ICF model. [Results] Wrist lateral deviation, upper-extremity speed of body function and education of personal factor were significantly associated with handwriting articulation. [Conclusion] Efforts to manage and improve the handwriting articulation of children with cerebral palsy should focus on wrist lateral deviation, upper-extremity speed, and education. PMID:27065517

  19. An investigation of the factors affecting handwriting articulation of school aged children with cerebral palsy based on the international classification of functioning, disability and health.

    PubMed

    Kim, Hee Young

    2016-01-01

    [Purpose] This study was designed to identify factors influencing handwriting articulation based on the international classification of functioning, disability and health (ICF) and to recommend effective evaluation and intervention strategies to improve the handwriting of children with cerebral palsy. [Subjects] The subjects were 96 elementary school children with cerebral palsy and the study was conducted from 04/07/2011 to 29/08/2011. [Methods] Factors related to handwriting articulation were investigated based on the ICF model. [Results] Wrist lateral deviation, upper-extremity speed of body function and education of personal factor were significantly associated with handwriting articulation. [Conclusion] Efforts to manage and improve the handwriting articulation of children with cerebral palsy should focus on wrist lateral deviation, upper-extremity speed, and education. PMID:27065517

  20. 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)

  1. 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…

  2. 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…

  3. 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…

  4. Hydrostatic determinants of cerebral perfusion

    SciTech Connect

    Wagner, E.M.; Traystman, R.J.

    1986-05-01

    We examined the cerebral blood flow response to alterations in perfusion pressure mediated through decreases in mean arterial pressure, increases in cerebrospinal fluid (CSF) pressure, and increases in jugular venous (JV) pressure in 42 pentobarbital anesthetized dogs. Each of these three pressures was independently controlled. Cerebral perfusion pressure was defined as mean arterial pressure minus JV or CSF pressure, depending on which was greater. Mean hemispheric blood flow was measured with the radiolabeled microsphere technique. Despite 30-mm Hg reductions in mean arterial pressure or increases in CSF or JV pressure, CBF did not change as long as the perfusion pressure remained greater than approximately 60 mm Hg. However, whenever perfusion pressure was reduced to an average of 48 mm Hg, cerebral blood flow decreased 27% to 33%. These results demonstrate the capacity of the cerebral vascular bed to respond similarly to changes in the perfusion pressure gradient obtained by decreasing mean arterial pressure, increasing JV pressure or increasing CSF pressure, and thereby support the above definition of cerebral perfusion pressure.

  5. 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.

  6. 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.

  7. Cerebral hemiatrophy: a clinicopathological report of two cases with a contribution to pathogenesis and differential diagnosis.

    PubMed

    Vosskämper, M; Schachenmayr, W

    1990-01-01

    "Cerebral hemiatrophy" describes a condition of different etiologies that is characterized by a marked asymmetry of cerebral hemispheres. Case reports of two different forms of cerebral hemiatrophy are presented. In the first case perinatal asphyxia led to severe white matter lesions with predominance on the left side and marked asymmetry of the pyramidal tracts. Symptoms were present immediately after birth ("primary cerebral hemiatrophy"). The second case displayed postictal cerebral hemiatrophy with a widespread loss of cortical neurons of the entire left hemisphere. The disease process started at the age of two years after a widely normal early development ("secondary cerebral hemiatrophy"). A modified classification of cerebral hemiatrophy is presented, and concepts of pathogenesis and differential diagnosis are discussed. PMID:2125535

  8. Cerebral venous sinus thrombosis

    PubMed Central

    Allroggen, H.; Abbott, R.

    2000-01-01

    Cerebral venous sinus thrombosis is a challenging condition because of its variability of clinical symptoms and signs. It is very often unrecognised at initial presentation. All age groups can be affected. Large sinuses such as the superior sagittal sinus are most frequently involved. Extensive collateral circulation within the cerebral venous system allows for a significant degree of compensation in the early stages of thrombus formation. Systemic inflammatory diseases and inherited as well as acquired coagulation disorders are frequent causes, although in up to 30% of cases no underlying cause can be identified. The oral contraceptive pill appears to be an important additional risk factor. The spectrum of clinical presentations ranges from headache with papilloedema to focal deficit, seizures and coma. Magnetic resonance imaging with venography is the investigation of choice; computed tomography alone will miss a significant number of cases. It has now been conclusively shown that intravenous heparin is the first-line treatment for cerebral venous sinus thrombosis because of its efficacy, safety and feasability. Local thrombolysis may be indicated in cases of deterioration, despite adequate heparinisation. This should be followed by oral anticoagulation for 3-6 months. The prognosis of cerebral venous sinus thrombosis is generally favourable. A high index of clinical suspicion is needed to diagnose this uncommon condition so that appropriate treatment can be initiated.


Keywords: cerebral venous sinus thrombosis PMID:10622773

  9. Cerebral Arteriosclerosis

    MedlinePlus

    ... Cerebral arteriosclerosis is the result of thickening and hardening of the walls of the arteries in the ... cause an ischemic stroke. When the thickening and hardening is uneven, arterial walls can develop bulges (called ...

  10. Cerebral hypoxia

    MedlinePlus

    ... death. Treatment depends on the cause of the hypoxia. Basic life support is most important. Treatment involves: Breathing ... Complications of cerebral hypoxia include a prolonged vegetative ... sleep-wake cycle, and eye opening, but the person is not alert ...

  11. 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.

  12. Cerebral Palsy (For Parents)

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Cerebral Palsy KidsHealth > For Parents > Cerebral Palsy Print A A ... kids who are living with the condition. About Cerebral Palsy Cerebral palsy is one of the most common ...

  13. 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. ...

  14. 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…

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

    PubMed

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

    2011-01-01

    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. PMID:21359174

  16. Gaze Behaviour during Interception in Children with Spastic Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    van Kampen, P. M.; Ledebt, A.; Smorenburg, A. R. P.; Vermeulen, R. J.; Kelder, M. E.; van der Kamp, J.; Savelsbergh, G. J. P.

    2012-01-01

    Anticipatory gaze behaviour during interceptive movements was investigated in children with Spastic Unilateral Cerebral Palsy (SUCP), and related to the side of the intracerebral lesion. Five children with lesions of the right hemisphere (RHL) and five children with lesions of the left hemisphere (LHL) had to walk towards and intercept a ball that…

  17. Efficacy of extracranial-intracranial bypass for progressive middle cerebral artery occlusion associated with active Sjögren's syndrome: case report.

    PubMed

    Sakata, Hiroyuki; Fujimura, Miki; Sato, Kenichi; Shimizu, Hiroaki; Tominaga, Teiji

    2014-09-01

    Sjögren syndrome affecting the major cerebral arteries is rare, and an optimal therapeutic strategy to counteract such a lesion has not yet been established. We herein report a case of a 39-year-old woman with a history of primary Sjögren syndrome, which had previously been treated with immunosuppressive therapy, manifesting with a crescendo transient ischemic attack because of left middle cerebral artery stenosis. Despite the administration of high doses of prednisolone and azathioprine for active Sjögren syndrome, the frequency of crescendo transient ischemic attacks increased with the progression of stenosis and magnetic resonance imaging showed the development of subacute cerebral infarction. Single-photon emission computed tomography with N-isopropyl[(123)I]-p-iodoamphetamine revealed apparent hemodynamic compromise in the affected cerebral hemisphere. In light of the increased risk of further progression of cerebral infarction, we decided to perform surgical revascularization in spite of her active inflammatory condition. The patient underwent extracranial-intracranial bypass without complications and was treated with intensive immunosuppressive therapy during the perioperative period. Based on our findings, we recommend surgical revascularization for occlusive cerebrovascular disease with hemodynamic compromise in combination with intensive immunosuppressive therapy, even in the active inflammatory state of autoimmune diseases, if ischemic symptoms are medically uncontrollable.

  18. Cerebral palsy.

    PubMed

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

    2014-04-01

    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.

  19. Models of hemispheric specialization in facial emotion perception--a reevaluation.

    PubMed

    Najt, Pablo; Bayer, Ulrike; Hausmann, Markus

    2013-02-01

    A considerable amount of research on functional cerebral asymmetries (FCAs) for facial emotion perception has shown conflicting support for three competing models: (i) the Right Hemisphere Hypothesis, (ii) the Valence-Specific Hypothesis, and (iii) the Approach/Withdrawal model. However, the majority of studies evaluating the Right Hemisphere or the Valence-Specific Hypotheses are rather limited by the small number of emotional expressions used. In addition, it is difficult to evaluate the Approach/Withdrawal Hypothesis due to insufficient data on anger and FCAs. The aim of the present study was (a) to review visual half field (VHF) studies of hemispheric specialization in facial emotion perception and (b) to reevaluate empirical evidence with respect to all three partly conflicting hypotheses. Results from the present study revealed a left visual field (LVF)/right hemisphere advantage for the perception of angry, fearful, and sad facial expressions and a right visual field (RVF)/left hemisphere advantage for the perception of happy expressions. Thus, FCAs for the perception of specific facial emotions do not fully support the Right Hemisphere Hypothesis, the Valence-Specific Hypothesis, or the Approach/Withdrawal model. A systematic literature review, together with the results of the present study, indicate a consistent LVF/right hemisphere advantage only for a subset of negative emotions including anger, fear and sadness, rather suggesting a "negative (only) valence model."

  20. Information processing in the separated hemispheres of callosotomy patients: does the analytic-holistic dichotomy hold?

    PubMed

    Trope, I; Rozin, P; Kemler Nelson, D; Gur, R C

    1992-07-01

    The characterization of the left and right cerebral hemispheres as analytic and holistic, respectively, was evaluated with callosotomy patients. This distinction was operationalized by reference to the work of Garner, Kemler Nelson, and their colleagues on separable (analytic) and integral (holistic) dimensions of cognition. In one experiment, patients were asked to make similarity judgments when faced with triads of stimuli such that one pair matched on a criterial attribute (analytic) and another pair showed a family resemblance (holistic). The right hemisphere showed a stronger bias to judge on the basis of the criterial attribute. In a second experiment, each hemisphere was engaged separately in a concept formation task. Depending on the exemplars in a particular set, analytic or holistic processing was seen in either hemisphere. However, the left hemisphere was more likely to engage in analytic processing. The results suggest that both hemispheres are capable of either type of processing and may use either mode, depending on the nature of the task and stimulus material. Thus, the analytic/holistic distinction may not provide a simple, generalizable description of information processing differences between the two hemispheres.

  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. Effects of cervical-lymphatic blockade on brain edema and infarction volume in cerebral ischemic rats.

    PubMed

    Si, Jinchao; Chen, Lianbi; Xia, Zuoli

    2006-10-31

    To observe the effects of cervical-lymphatic blockade (CLB) on brain edema and infarction volume of ischemic (MCAO) rat, we examined changes in cerebral water content, Ca2+ and glutamate concentrations, cerebral infarction volume and mRNA expression levels of N-methyl-D-aspartame receptor 1 (NMDA receptor 1) in the ischemic (left) hemisphere. The present results demonstrated that all the above indices in rats with middle cerebral artery occlusion plus cervical lymphatic blockade (MCAO+CLB) were markedly higher than those with only middle cerebral artery occlusion (MCAO) at different time points. These results indicated [corrected] that CLB can aggravate cerebral ischemia by increasing brain edema and infarction volume.

  4. Impaired cerebral autoregulation and brain injury in newborns with hypoxic-ischemic encephalopathy treated with hypothermia.

    PubMed

    Massaro, An N; Govindan, R B; Vezina, Gilbert; Chang, Taeun; Andescavage, Nickie N; Wang, Yunfei; Al-Shargabi, Tareq; Metzler, Marina; Harris, Kari; du Plessis, Adre J

    2015-08-01

    Impaired cerebral autoregulation may contribute to secondary injury in newborns with hypoxic-ischemic encephalopathy (HIE). Continuous, noninvasive assessment of cerebral pressure autoregulation can be achieved with bedside near-infrared spectroscopy (NIRS) and systemic mean arterial blood pressure (MAP) monitoring. This study aimed to evaluate whether impaired cerebral autoregulation measured by NIRS-MAP monitoring during therapeutic hypothermia and rewarming relates to outcome in 36 newborns with HIE. Spectral coherence analysis between NIRS and MAP was used to quantify changes in the duration [pressure passivity index (PPI)] and magnitude (gain) of cerebral autoregulatory impairment. Higher PPI in both cerebral hemispheres and gain in the right hemisphere were associated with neonatal adverse outcomes [death or detectable brain injury by magnetic resonance imaging (MRI), P < 0.001]. NIRS-MAP monitoring of cerebral autoregulation can provide an ongoing physiological biomarker that may help direct care in perinatal brain injury.

  5. Impaired cerebral autoregulation and brain injury in newborns with hypoxic-ischemic encephalopathy treated with hypothermia.

    PubMed

    Massaro, An N; Govindan, R B; Vezina, Gilbert; Chang, Taeun; Andescavage, Nickie N; Wang, Yunfei; Al-Shargabi, Tareq; Metzler, Marina; Harris, Kari; du Plessis, Adre J

    2015-08-01

    Impaired cerebral autoregulation may contribute to secondary injury in newborns with hypoxic-ischemic encephalopathy (HIE). Continuous, noninvasive assessment of cerebral pressure autoregulation can be achieved with bedside near-infrared spectroscopy (NIRS) and systemic mean arterial blood pressure (MAP) monitoring. This study aimed to evaluate whether impaired cerebral autoregulation measured by NIRS-MAP monitoring during therapeutic hypothermia and rewarming relates to outcome in 36 newborns with HIE. Spectral coherence analysis between NIRS and MAP was used to quantify changes in the duration [pressure passivity index (PPI)] and magnitude (gain) of cerebral autoregulatory impairment. Higher PPI in both cerebral hemispheres and gain in the right hemisphere were associated with neonatal adverse outcomes [death or detectable brain injury by magnetic resonance imaging (MRI), P < 0.001]. NIRS-MAP monitoring of cerebral autoregulation can provide an ongoing physiological biomarker that may help direct care in perinatal brain injury. PMID:26063779

  6. 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

  7. 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

  8. 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.

  9. 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. PMID:26952051

  10. 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…

  11. Hypnosis in the right hemisphere.

    PubMed

    Kihlstrom, John F; Glisky, Martha L; McGovern, Susan; Rapcsak, Steven Z; Mennemeier, Mark S

    2013-02-01

    Speculations about the neural substrates of hypnosis have often focused on the right hemisphere (RH), implying that RH damage should impair hypnotic responsiveness more than left-hemisphere (LH) damage. The present study examined the performance of a patient who suffered a stroke destroying most of his LH, on slightly modified versions of two hypnotizability scales. This patient was at least modestly hypnotizable, as indicated in particular by the arm rigidity and age regression items, suggesting that hypnosis can be mediated by the RH alone - provided that the language capacities normally found in the LH remain available. A further study of 16 patients with unilateral strokes of the LH or RH found no substantial differences in hypnotizability between the two groups. Future neuropsychological studies of hypnosis might explore the dorsal/ventral or anterior/posterior dichotomies, with special emphasis on the role of prefrontal cortex.

  12. 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.

  13. Cerebral lateralization in simultaneous interpretation.

    PubMed

    Fabbro, F; Gran, L; Basso, G; Bava, A

    1990-07-01

    Cerebral asymmetries for L1 (Italian), L2 (English), and L3 (French, German, Spanish, or Russian) were studied, by using a verbal-manual interference paradigm, in a group of Italian right-handed polyglot female students at the Scuola Superiore di Lingue Moderne per Interpreti e Traduttori (SSLM-School for Interpreters and Translators) of the University of Trieste and in a control group of right-handed monolingual female students at the Medical School of the University of Trieste. In an automatic speech production task no significant cerebral lateralization was found for the mother tongue (L1) either in the interpreting students or in the control group; the interpreting students were not significantly lateralized for the third language (L3), while weak left hemispheric lateralization was shown for L2. A significantly higher degree of verbal-manual interference was found for L1 than for L2 and L3. A significantly higher disruption rate occurred in the meaning-based mode of simultaneous interpretation (from L2 into L1 and vice versa) than in the word-for-word mode (from L2 into L1 and vice versa). No significant overall or hemispheric differences were found during simultaneous interpretation from L1 into L2 or from L2 into L1. PMID:2207622

  14. Focal hemisphere and visuoperceptual categorization.

    PubMed Central

    Bisiach, E; Capitani, E; Spinnler, H

    1975-01-01

    Visuoperceptual categorization was investigated in patients with unilateral brain damage by a task in which meaningless shapes had to be classified with reference to a number of prototype patterns. Right brain-damaged subjects with visual field defect turned out to have a narrower categorization span. As this outcome seems to be scarcely consonant with a lower level disorder of visual processing, a major competence of the right hemisphere is suggested for visuoperceptual categorization. PMID:1206421

  15. 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…

  16. Mixing with piecewise isometries on a hemispherical shell

    NASA Astrophysics Data System (ADS)

    Park, Paul P.; Umbanhowar, Paul B.; Ottino, Julio M.; Lueptow, Richard M.

    2016-07-01

    We introduce mixing with piecewise isometries (PWIs) on a hemispherical shell, which mimics features of mixing by cutting and shuffling in spherical shells half-filled with granular media. For each PWI, there is an inherent structure on the hemispherical shell known as the exceptional set E, and a particular subset of E, E+, provides insight into how the structure affects mixing. Computer simulations of PWIs are used to visualize mixing and approximations of E+ to demonstrate their connection. While initial conditions of unmixed materials add a layer of complexity, the inherent structure of E+ defines fundamental aspects of mixing by cutting and shuffling.

  17. 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.

  18. Hemispheric specialization of abacus experts in mental calculation: evidence from the results of time-sharing tasks.

    PubMed

    Hatta, T; Ikeda, K

    1988-01-01

    Hemispheric specialization for mental calculation and verbal tasks in abacus (Soroban in Japanese) experts and control subjects was tested using time-sharing tasks. In Experiment 1, the effects of auditorily presented mental calculation and news-listening tasks on sequential finger tappings were examined. The results revealed that in the mental calculation condition, abacus experts showed greater interference effects on left hand tapping, whereas control subjects showed greater interference effects on right hand tapping (as compared to left hand). In the news-listening condition, abacus experts showed no hand difference while the controls showed greater interference effects on the right hand. In Experiment 2, the effects of visually presented mental calculation and word-reading tasks on sequential finger tapping were examined. The results revealed that in the mental calculation condition, abacus experts showed a non-significant tendency towards greater interference in the left hand whereas the controls showed no hand difference. In the word-reading condition, both abacus experts and controls showed greater interference in the right hand than in the left hand. In Experiment 3, intermediate and upper-rank abacus experts performed a similar task to Experiment 1 under two instruction conditions. The results of this control experiment confirmed that a greater left hand reduction in calculation of abacus experts is not due to subject's cognitive mode but due to the amount of abacus learning experience. These data suggest that (1) learning experiences can affect the pattern of cerebral specialization through the change of approaches to perform cognitive tasks, and (2) the right hemisphere engages in mental calculation for the abacus experts whereas the left hemisphere contributes to mental calculation in ordinary people having no experience of abacus learning.

  19. 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.

  20. 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…

  1. 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…

  2. 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…

  3. Cerebral White Matter

    PubMed Central

    Schmahmann, Jeremy D.; Smith, Eric E.; Eichler, Florian S.; Filley, Christopher M.

    2013-01-01

    Lesions of the cerebral white matter (WM) result in focal neurobehavioral syndromes, neuropsychiatric phenomena, and dementia. The cerebral WM contains fiber pathways that convey axons linking cerebral cortical areas with each other and with subcortical structures, facilitating the distributed neural circuits that subserve sensorimotor function, intellect, and emotion. Recent neuroanatomical investigations reveal that these neural circuits are topographically linked by five groupings of fiber tracts emanating from every neocortical area: (1) cortico-cortical association fibers; (2) corticostriatal fibers; (3) commissural fibers; and cortico-subcortical pathways to (4) thalamus and (5) pontocerebellar system, brain stem, and/or spinal cord. Lesions of association fibers prevent communication between cortical areas engaged in different domains of behavior. Lesions of subcortical structures or projection/striatal fibers disrupt the contribution of subcortical nodes to behavior. Disconnection syndromes thus result from lesions of the cerebral cortex, subcortical structures, and WM tracts that link the nodes that make up the distributed circuits. The nature and the severity of the clinical manifestations of WM lesions are determined, in large part, by the location of the pathology: discrete neurological and neuropsychiatric symptoms result from focal WM lesions, whereas cognitive impairment across multiple domains—WM dementia—occurs in the setting of diffuse WM disease. We present a detailed review of the conditions affecting WM that produce these neurobehavioral syndromes, and consider the pathophysiology, clinical effects, and broad significance of the effects of aging and vascular compromise on cerebral WM, in an attempt to help further the understanding, diagnosis, and treatment of these disorders. PMID:18990132

  4. 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.

  5. 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. PMID:4714107

  6. 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

  7. Priming vs. rhyming: orthographic and phonological representations in the left and right hemispheres.

    PubMed

    Lindell, Annukka K; Lum, Jarrad A G

    2008-11-01

    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 hypothesis and shed light on sex differences in the phonological processing capabilities of the left and right hemispheres, we conducted two experiments. Experiment 1 assessed phonological activation implicitly (masked homophone priming), testing 52 (M=25, F=27; mean age 19.23years, SD 1.64years) strongly right-handed participants. Experiment 2 subsequently assessed the explicit recruitment of phonology (rhyme judgement), testing 50 (M=25, F=25; mean age 19.67years, SD 2.05years) strongly right-handed participants. In both experiments the orthographic overlap between stimulus pairs was strictly controlled using DICE [Brew, C., & McKelvie, D. (1996). Word-pair extraction for lexicography. In K. Oflazer & H. Somers (Eds.), Proceedings of the second international conference on new methods in language processing (pp. 45-55). Ankara: VCH], such that pairs shared (a) high orthographic and phonological similarity (e.g., not-KNOT); (b) high orthographic and low phonological similarity (e.g., pint-HINT); (c) low orthographic and high phonological similarity (e.g., use-EWES); or (d) low orthographic and low phonological similarity (e.g., kind-DONE). As anticipated, high orthographic similarity facilitated both left and right hemisphere performance, whereas the left hemisphere showed greater facility when phonological similarity was high. This difference in hemispheric processing of phonological representations was especially pronounced in males, whereas female performance was far less sensitive to visual field of presentation across both implicit and explicit phonological tasks. As such, the findings offer behavioural evidence indicating

  8. Cerebral Laterality and Verbal-Performance Discrepancies in Intelligence.

    ERIC Educational Resources Information Center

    Dean, Raymond S.

    1979-01-01

    The cerebral laterality of children with various configurations of verbal-performance discrepancies was inferred with an objective measure of lateral preference using Verbal and Performance IQ scores of the WISC-R. Results were interpreted as lending support to the notion of competition antagonism between cortical hemispheres and a possible…

  9. 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.…

  10. 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…

  11. The Right Hemisphere in Esthetic Perception

    PubMed Central

    Bromberger, Bianca; Sternschein, Rebecca; Widick, Page; Smith, William; Chatterjee, Anjan

    2011-01-01

    Little about the neuropsychology of art perception and evaluation is known. Most neuropsychological approaches to art have focused on art production and have been anecdotal and qualitative. The field is in desperate need of quantitative methods if it is to advance. Here, we combine a quantitative approach to the assessment of art with modern voxel-lesion-symptom-mapping methods to determine brain–behavior relationships in art perception. We hypothesized that perception of different attributes of art are likely to be disrupted by damage to different regions of the brain. Twenty participants with right hemisphere damage were given the Assessment of Art Attributes, which is designed to quantify judgments of descriptive attributes of visual art. Each participant rated 24 paintings on 6 conceptual attributes (depictive accuracy, abstractness, emotion, symbolism, realism, and animacy) and 6 perceptual attributes (depth, color temperature, color saturation, balance, stroke, and simplicity) and their interest in and preference for these paintings. Deviation scores were obtained for each brain-damaged participant for each attribute based on correlations with group average ratings from 30 age-matched healthy participants. Right hemisphere damage affected participants’ judgments of abstractness, accuracy, and stroke quality. Damage to areas within different parts of the frontal parietal and lateral temporal cortices produced deviation in judgments in four of six conceptual attributes (abstractness, symbolism, realism, and animacy). Of the formal attributes, only depth was affected by inferior prefrontal damage. No areas of brain damage were associated with deviations in interestingness or preference judgments. The perception of conceptual and formal attributes in artwork may in part dissociate from each other and from evaluative judgments. More generally, this approach demonstrates the feasibility of quantitative approaches to the neuropsychology of art. PMID:22016728

  12. Employees with Cerebral Palsy

    MedlinePlus

    ... Resources Home | Accommodation and Compliance Series: Employees with Cerebral Palsy (CP) By Eddie Whidden, MA Preface Introduction Information About ... SOAR) at http://AskJAN.org/soar. Information about Cerebral Palsy (CP) What is CP? Cerebral palsy is a ...

  13. Cerebral Aneurysms Fact Sheet

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS Cerebral Aneurysms Fact Sheet See a list of all NINDS ... I get more information? What is a cerebral aneurysm? A cerebral aneurysm (also known as an intracranial ...

  14. Acute vertigo due to hemispheric stroke: a case report and comprehensive review of the literature.

    PubMed

    von Brevern, Michael; Süßmilch, Sina; Zeise, Daniel

    2014-04-15

    Acute cortical lesions rarely cause vertigo. We report a 51-year-old patient presenting with an acute vestibular syndrome including spontaneous vertigo and nystagmus, lateropulsion and nausea due to middle cerebral artery infarction. The central origin of the acute vestibular syndrome was revealed by a normal head impulse test. A comprehensive literature review on patients with hemispheric stroke manifesting with acute vertigo is provided. Typically, patients with an acute vestibular syndrome due to cortical stroke have involvement of the temporoparietal junction.

  15. Regional cerebral blood flow characteristics of the Sturge-Weber syndrome

    SciTech Connect

    Riela, A.R.; Stump, D.A.; Roach, E.S.; McLean, W.T. Jr.; Garcia, J.C.

    1985-03-01

    Four patients with the Sturge-Weber syndrome were studied using the non-invasive Xenon-133 inhalation technique. All four patients had decreased regional cerebral blood flow in the area of their lesion, and in two patients who were subsequently tested with 5% carbon dioxide inhalation, impaired vasomotor reactivity was documented. Diminished regional cerebral blood flow is consistent with previously described nuclide flow studies which demonstrated a delay in the initial perfusion blush in the region of the abnormal vasculature. The focal decrease in blood flow was greatest in the most severely affected patient, but was also prominent in the two younger patients, both of whom have excellent neurologic function. These studies suggest that localized decrease in blood flow and vasomotor dysfunction in Sturge-Weber syndrome can precede the occurrence of severe neurologic impairment and extensive cerebral atrophy and possibly be a major contributing factor in progressive dysfunction. A secondary observation was that the blood flow in the unaffected hemisphere was significantly greater in two children compared to the two adults and was similar to the age-related differences reported for normal children and adults.

  16. Bilingual language lateralization: a meta-analytic tale of two hemispheres.

    PubMed

    Hull, Rachel; Vaid, Jyotsna

    2007-05-15

    Two meta-analyses of 66 behavioral studies examined variables influencing functional cerebral lateralization of each language of brain-intact bilingual adults. Functional lateralization was found to be primarily influenced by age of onset of bilingualism: bilinguals who acquired both languages by 6 years of age showed bilateral hemispheric involvement for both languages, whereas those who acquired their second language after age 6 showed left hemisphere dominance for both languages. Moreover, among late bilinguals, left hemisphere involvement was found to be greater for those less proficient in their second language, those whose second language was English, and for studies involving dichotic listening paradigms; early bilinguals instead showed bilateral involvement in every condition. Implications of the observed differences in lateralization between early and late bilinguals are explored for existing theories of bilingualism and for neurocognitive models of brain functional organization of language.

  17. Climate modelling: Northern Hemisphere circulation.

    PubMed

    Gillett, Nathan P

    2005-09-22

    Air pressure at sea level during winter has decreased over the Arctic and increased in the Northern Hemisphere subtropics in recent decades, a change that has been associated with 50% of the Eurasian winter warming observed over the past 30 years, with 60% of the rainfall increase in Scotland and with 60% of the rainfall decrease in Spain. This trend is inconsistent with the simulated response to greenhouse-gas and sulphate-aerosol changes, but it has been proposed that other climate influences--such as ozone depletion--could account for the discrepancy. Here I compare observed Northern Hemisphere sea-level pressure trends with those simulated in response to all the major human and natural climate influences in nine state-of-the-art coupled climate models over the past 50 years. I find that these models all underestimate the circulation trend. This inconsistency suggests that we cannot yet simulate changes in this important property of the climate system or accurately predict regional climate changes.

  18. Induced hypertension for the treatment of cerebral ischemia after subarachnoid hemorrhage. Direct effect on cerebral blood flow

    SciTech Connect

    Muizelaar, J.P.; Becker, D.P.

    1986-04-01

    The best treatment for symptomatic cerebral ischemia from presumed vasospasm after aneurysmal subarachnoid hemorrhage remains a matter of controversy. A direct effect of any treatment modality on regional cerebral blood flow has never been documented. In a series of 43 patients operated on for ruptured anterior circulation aneurysms, five patients (11.6%) developed clinical signs of cerebral ischemia postoperatively. In four of those patients, the diagnosis of vasospasm was made with measurements of cerebral blood flow (133Xe inhalation or intravenous injection, 10-16 detectors, cerebral blood flow infinity). Treatment with induced arterial hypertension with phenylephrine was instituted. Hemodilution was instituted in one patient; the other three patients already had hematocrits in the range of 33. Within 1 hour, the cerebral blood flow measurement was repeated to document the effect of treatment. The average pretreatment hemispherical blood flow on the operated side was 18.8 mL/100 g per minute, on the contralateral side 21.0 mL/100 g per minute. With treatment these flows increased to 30.8 and 35.8 mL/100 g per minute, respectively. There was also an immediate and obvious positive clinical effect in all patients. The role of measurement of cerebral blood flow in the clinical management of vasospasm is discussed. We stress the theoretical and practical advances of measurements of cerebral blood flow over cerebral angiography, especially in comatose patients.

  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 Microdialysis.

    PubMed

    Young, Bethany; Kalanuria, Atul; Kumar, Monisha; Burke, Kathryn; Balu, Ramani; Amendolia, Olivia; McNulty, Kyle; Marion, BethAnn; Beckmann, Brittany; Ciocco, Lauren; Miller, Kimberly; Schuele, Donnamarie; Maloney-Wilensky, Eileen; Frangos, Suzanne; Wright, Danielle

    2016-03-01

    A variety of neuromonitoring techniques are available to aid in the care of neurocritically ill patients. However, traditional monitors lack the ability to measure brain biochemistry and may provide inadequate warning of potentially reversible deleterious conditions. Cerebral microdialysis (CMD) is a safe, novel method of monitoring regional brain biochemistry. Analysis of CMD analytes as part of a multimodal approach may help inform clinical decision making, guide medical treatments, and aid in prognostication of patient outcome. Its use is most frequently documented in traumatic brain injury and subarachnoid hemorrhage. Incorporating CMD into clinical practice is a multidisciplinary effort.

  1. Effect of glycerol on ischemic cerebral edema assessed by magnetic resonance imaging.

    PubMed

    Sakamaki, Masanori; Igarashi, Hironaka; Nishiyama, Yutaka; Hagiwara, Hiroshi; Ando, Jun; Chishiki, Tetsurou; Curran, Brian C; Katayama, Yasuo

    2003-05-15

    The aim of this study is to assess the anticerebral edema effect of glycerol on a large cerebral infarction with magnetic resonance imaging (MRI). Glycerol, which is widely used as an osmotic agent against cerebral edema, could exacerbate brain tissue shift, since it has been suggested that glycerol might shrink a noninfarcted hemisphere and worsen the mass effect after a large hemispheric cerebral infarction. To investigate these issues, changes in a large hemispheric infarction with cerebral edema were studied using MRI before and after glycerol administration. Infarct volumes, normal brain tissue volumes and lateral ventricle volumes, in addition to signal intensities of T(2)-weighted images, were measured in six patients before and after administration of 300 ml of glycerol. Ventricle volumes were significantly increased (p=0.0015) and the T(2) signal intensity of the post-treatment ischemic region decreased after glycerol administration. In contrast, no significant differences in either cerebral volume or T(2) signal intensity were seen in the noninfarcted hemisphere before and after administration. Our data suggest that glycerol does not exacerbate the mass effect on a large hemispheric infarction. PMID:12686405

  2. Hemispheric Asymmetries: The Comparative View

    PubMed Central

    Ocklenburg, Sebastian; Güntürkün, Onur

    2012-01-01

    Hemispheric asymmetries play an important role in almost all cognitive functions. For more than a century, they were considered to be uniquely human but now an increasing number of findings in all vertebrate classes make it likely that we inherited our asymmetries from common ancestors. Thus, studying animal models could provide unique insights into the mechanisms of lateralization. We outline three such avenues of research by providing an overview of experiments on left–right differences in the connectivity of sensory systems, the embryonic determinants of brain asymmetries, and the genetics of lateralization. All these lines of studies could provide a wealth of insights into our own asymmetries that should and will be exploited by future analyses. PMID:22303295

  3. Electroformation of uranium hemispherical shells

    SciTech Connect

    Marshall, S.L.; Redey, L.; Vandegrift, G.F.; Vissers, D.R.

    1989-11-01

    This effort was directed at developing an electrochemical process for forming uniform and dendrite-free deposits of uranium from molten salts. This process is to be used for the electroformation of free-standing hemispherical shells of uranium for nuclear applications. Electrodeposition of uranium onto a substrate was accomplished with a fused chloride mixture containing 42 wt% UCl{sub 3} and a fused chloride-fluoride mixture containing 4 wt % UF{sub 4}. Under pulsed potential control at 504{degree}C, the chloride-fluoride mixture yielded the widest range of plating conditions for which dendrites could be avoided. Bipolar current pulse plating with both electrolytes gave good results, and successful application of this technique to a large tubular cathode has been demonstrated. 24 refs., 10 figs.

  4. 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. PMID:25609971

  5. 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.

  6. Asymmetries in the cerebral dimensions and fissures of the dog.

    PubMed

    Tan, U; Calişkan, S

    1987-02-01

    The surface dimensions and fissures of the right and left cerebral hemispheres were compared in dogs. The right hemisphere was significantly larger in length and height than the left hemisphere; there was no significant difference in the width of the right and left hemispheres. The mean length of the cruciate sulcus did not significantly differ on the right and left sides except individual for asymmetries. The difference in the mean length of the right and left Sylvian fissures was not significant, but the right Sylvian fissure was significantly lower than the left. The base of the right planum temporale tended to be larger than the left. These anatomical asymmetries did not correlate with paw preference. The data are consistent with notion that asymmetrical patterns cannot be a distinctive feature of the human brain.

  7. 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.

  8. Right hemisphere control of visuospatial attention in near space.

    PubMed

    Longo, Matthew R; Trippier, Sarah; Vagnoni, Eleonora; Lourenco, Stella F

    2015-04-01

    Traditionally, the right cerebral hemisphere has been considered to be specialized for spatial attention and orienting. A large body of research has demonstrated dissociable representations of the near space immediately surrounding the body and the more distance far space. In this study, we investigated whether right hemisphere activations commonly reported for tasks involving spatial attention (such as the line bisection and landmark tasks) are specific to stimuli presented in near space. In separate blocks of trials, participants judged either whether a vertical transector was to the left or right of the centre of a line (landmark task) or whether the line was red or blue (colour task). Stimuli were seen from four distances (30, 60, 90, 120 cm). We used EEG to measure an ERP component (the 'line-bisection effect') specific to the direction of spatial attention (i.e., landmark minus colour). Consistent with previous results, spatial attention produced a right-lateralized negativity over occipito-parietal channels. The magnitude of this negativity was inversely related to viewing distance, being largest in near space and reduced in far space. These results suggest that the right occipito-temporal cortex may be specialized not just for the orientation of spatial attention generally, but specifically for orienting attention in the near space immediately surrounding the body.

  9. 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…

  10. The right-hemisphere and valence hypotheses: could they both be right (and sometimes left)?

    PubMed Central

    Yurgelun-Todd, Deborah A.

    2007-01-01

    The two halves of the brain are believed to play different roles in emotional processing, but the specific contribution of each hemisphere continues to be debated. The right-hemisphere hypothesis suggests that the right cerebrum is dominant for processing all emotions regardless of affective valence, whereas the valence specific hypothesis posits that the left hemisphere is specialized for processing positive affect while the right hemisphere is specialized for negative affect. Here, healthy participants viewed two split visual-field facial affect perception tasks during functional magnetic resonance imaging, one presenting chimeric happy faces (i.e. half happy/half neutral) and the other presenting identical sad chimera (i.e. half sad/half neutral), each masked immediately by a neutral face. Results suggest that the posterior right hemisphere is generically activated during non-conscious emotional face perception regardless of affective valence, although greater activation is produced by negative facial cues. The posterior left hemisphere was generally less activated by emotional faces, but also appeared to recruit bilateral anterior brain regions in a valence-specific manner. Findings suggest simultaneous operation of aspects of both hypotheses, suggesting that these two rival theories may not actually be in opposition, but may instead reflect different facets of a complex distributed emotion processing system. PMID:18985144

  11. [Cerebral palsy].

    PubMed

    Malagón Valdez, Jorge

    2007-01-01

    The term cerebral palsy (CP), is used for a great number of clinical neurological syndromes. The syndromes are characterized by having a common cause, motor defects. It is important, because they can cause a brain damage by presenting motor defects and some associated deficiencies, such as mental deficiency, epilepsy, language and visual defects and pseudobulbar paralysis, with the non-evolving fact. Some authors prefer using terms such as "non-evolving encephalopathies". In the treatment the utility of prevention programs of early stimulation and special rehabilitation methods, and treatment of associated deficiencies such as epilepsy, mental deficiency, language, audition and visual problems, and the attention deficit improve the prognosis in an important way. The prognosis depends on the severity of the disease and the associated manifestations. PMID:18422084

  12. 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. PMID:19318973

  13. Reactivity of sensorimotor oscillations is altered in children with hemiplegic cerebral palsy: A magnetoencephalographic study.

    PubMed

    Pihko, Elina; Nevalainen, Päivi; Vaalto, Selja; Laaksonen, Kristina; Mäenpää, Helena; Valanne, Leena; Lauronen, Leena

    2014-08-01

    Cerebral palsy (CP) is characterized by difficulty in control of movement and posture due to brain damage during early development. In addition, tactile discrimination deficits are prevalent in CP. To study the function of somatosensory and motor systems in CP, we compared the reactivity of sensorimotor cortical oscillations to median nerve stimulation in 12 hemiplegic CP children vs. 12 typically developing children using magnetoencephalography. We also determined the primary cortical somatosensory and motor representation areas of the affected hand in the CP children using somatosensory-evoked magnetic fields and navigated transcranial magnetic stimulation, respectively. We hypothesized that the reactivity of the sensorimotor oscillations in alpha (10 Hz) and beta (20 Hz) bands would be altered in CP and that the beta-band reactivity would depend on the individual pattern of motor representation. Accordingly, in children with CP, suppression and rebound of both oscillations after stimulation of the contralateral hand were smaller in the lesioned than intact hemisphere. Furthermore, in two of the three children with CP having ipsilateral motor representation, the beta- but not alpha-band modulations were absent in both hemispheres after affected hand stimulation suggesting abnormal sensorimotor network interactions in these individuals. The results are consistent with widespread alterations in information processing in the sensorimotor system and complement current understanding of sensorimotor network development after early brain insults. Precise knowledge of the functional sensorimotor network organization may be useful in tailoring individual rehabilitation for people with CP.

  14. 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

  15. Hemispheric competence for auditory spatial representation.

    PubMed

    Spierer, Lucas; Bellmann-Thiran, Anne; Maeder, Philippe; Murray, Micah M; Clarke, Stephanie

    2009-07-01

    Sound localization relies on the analysis of interaural time and intensity differences, as well as attenuation patterns by the outer ear. We investigated the relative contributions of interaural time and intensity difference cues to sound localization by testing 60 healthy subjects: 25 with focal left and 25 with focal right hemispheric brain damage. Group and single-case behavioural analyses, as well as anatomo-clinical correlations, confirmed that deficits were more frequent and much more severe after right than left hemispheric lesions and for the processing of interaural time than intensity difference cues. For spatial processing based on interaural time difference cues, different error types were evident in the individual data. Deficits in discriminating between neighbouring positions occurred in both hemispaces after focal right hemispheric brain damage, but were restricted to the contralesional hemispace after focal left hemispheric brain damage. Alloacusis (perceptual shifts across the midline) occurred only after focal right hemispheric brain damage and was associated with minor or severe deficits in position discrimination. During spatial processing based on interaural intensity cues, deficits were less severe in the right hemispheric brain damage than left hemispheric brain damage group and no alloacusis occurred. These results, matched to anatomical data, suggest the existence of a binaural sound localization system predominantly based on interaural time difference cues and primarily supported by the right hemisphere. More generally, our data suggest that two distinct mechanisms contribute to: (i) the precise computation of spatial coordinates allowing spatial comparison within the contralateral hemispace for the left hemisphere and the whole space for the right hemisphere; and (ii) the building up of global auditory spatial representations in right temporo-parietal cortices.

  16. Ontogenesis of hemispheric specialization: apraxia associated with congenital left hemisphere lesions.

    PubMed

    Nass, R

    1983-12-01

    In adults apraxia is more common after left-hemisphere damage. The engram for control of skilled motor movements has therefore been considered a specialized function of the left hemisphere. The ontogenesis of motor control was studied in a group of prepubertal children with congenital unilateral hemispheric lesions. Left-hemisphere lesions caused greater impairment of rapid independent finger movements, suggesting that specialization for motor control is innately programmed in the left hemisphere. No subject evidenced apraxia to verbal command, but adult-like performance is not yet expected at the age the group was tested, and effects of side of lesion could appear later. PMID:6664762

  17. 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.

  18. 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.

  19. The Asgard Hemisphere of Callisto

    NASA Technical Reports Server (NTRS)

    1997-01-01

    False color view of a portion of the leading hemisphere of Jupiter's moon Callisto as seen through the infrared filters of the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft. North is to the top of the picture and the sun illuminates the surface from the east. More recent impacts have excavated bright, relatively clean ice from beneath Callisto's battered surface. Callisto's dark mottled appearance may be due to contamination by non-ice components contributed by impactors or concentrated in a residue as ice is removed. This color composite image is centered on longitude 139 West and encompasses an area about 1000 miles (1600 kilometers) by 2470 miles (4000 kilometers). The images were obtained on November 3rd, 1996.

    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

  20. 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.

  1. Cerebral lateralization and cognitive deficits after congenital hemiparesis.

    PubMed

    Kolk, Anneli; Talvik, Tiina

    2002-11-01

    The purpose of this study was to investigate whether and how handedness is related to the processes of cerebral lateralization and cognitive performance in children with congenital insult. Fifty-six children (31 males and 25 females) with congenital hemiparesis and 14 control subjects were investigated. Of these children, 32 had a left hemisphere lesion, and 24 children had a right hemisphere lesion. There were 30 right-handed, 23 left-handed, and three ambidextrous children in the study group. The neuropsychologic assessment was performed using the NEPSY (a developmental neuropsychological assessment of child development) test battery. We found that 41% of the hemiparetic children and 72% of the children with a left hemisphere lesion were left-handed. In children contralateral to lesion handedness (no evidence of interhemispheric transfer of functions), we found diffuse cognitive deficits with impaired language abilities and poor visuomotor and narrative memory processing. In contrast, children with ipsilateral to brain lesion handedness (interhemispheric transfer of functions) demonstrated minimal or moderate side-specific cognitive dysfunction. Right-handed children with a right hemisphere lesion had attention, spatial, and short-term memory problems; left-handed children with a left hemisphere lesion had receptive language and visuomotor difficulties. Handedness combined with neuropsychologic assessment is a reliable indicator of the processes of cerebral reorganization after early brain insult. PMID:12504203

  2. [A case of cerebral embolism due to cardiac myxoma presenting with multiple cerebral microaneurysms detected on first MRI scans].

    PubMed

    Sato, Takahiro; Saji, Naoki; Kobayashi, Kazuto; Shibazaki, Kensaku; Kimura, Kazumi

    2016-01-01

    A 64-year-old man developed right arm weakness and dysarthria, and was admitted to our hospital. Diffusion-weighted magnetic resonance imaging of the brain showed a high intensity area in the frontal lobe. T2*-weighted images showed multiple spotty low intensity lesions in bilateral cerebral hemispheres, mimicking cerebral microbleeds. Cerebral angiography showed multiple aneurysms in the anterior, middle, posterior cerebral arteries and cerebellar arteries. Transthoracic echocardiography revealed a floating structure in the left atrial chamber, indicating cardiac myxoma. We diagnosed cardioembolic ischemic stroke due to left atrial myxoma. Cardiac surgery for excision of a left atrial myxoma was performed on the 3rd hospital day. Multiple aneurysms should be taken into account for differential diagnosis in patients with cardiac myxoma and with atypical spotty low intensity on T2*-weighted images. PMID:26797485

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Cerebral rheumatoid vasculitis: a case report

    PubMed Central

    2012-01-01

    Introduction Central nervous system involvement in rheumatoid arthritis is infrequent. The most frequent neurological manifestations of rheumatoid arthritis are peripheral neuropathy and cervical spinal cord compression due to subluxation of the cervical vertebrae. Cerebral rheumatoid vasculitis is an uncommon and serious complication which can be life-threatening. Case presentation A 52-year-old North African Tunisian Caucasian woman presented with a six-week history of headache. She had suffered seropositive and destructive rheumatoid arthritis for nine years without any extra-articular complications. Magnetic resonance imaging of the brain with the T2 sequence showed high-intensity signal images at the frontal and parietal cortico-subcortical junction suggesting hemispheric vasculitis. Conclusions Cerebral vasculitis is an infrequent complication in rheumatoid arthritis which is associated with high morbidity and in some cases can be life-threatening. Early assessment and a high index of suspicion to recognize such complications are essential in managing these patients. PMID:22974191

  9. 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.

  10. 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.

  11. Hemispheric asymmetries and prosodic emotion recognition deficits in Parkinson's disease.

    PubMed

    Ventura, Maria I; Baynes, Kathleen; Sigvardt, Karen A; Unruh, April M; Acklin, Sarah S; Kirsch, Heidi E; Disbrow, Elizabeth A

    2012-07-01

    While Parkinson's disease (PD) has traditionally been described as a movement disorder, there is growing evidence of cognitive and social deficits associated with the disease. However, few studies have looked at multi-modal social cognitive deficits in patients with PD. We studied lateralization of both prosodic and facial emotion recognition (the ability to recognize emotional valence from either tone of voice or from facial expressions) in PD. The Comprehensive Affect Testing System (CATS) is a well-validated test of human emotion processing that has been used to study emotion recognition in several major clinical populations, but never before in PD. We administered an abbreviated version of CATS (CATS-A) to 24 medicated PD participants and 12 age-matched controls. PD participants were divided into two groups, based on side of symptom onset and unilateral motor symptom severity: left-affected (N = 12) or right-affected PD participants (N = 12). CATS-A is a computer-based button press task with eight subtests relevant to prosodic and facial emotion recognition. Left-affected PD participants with inferred predominant right-hemisphere pathology were expected to have difficulty with prosodic emotion recognition since there is evidence that the processing of prosodic information is right-hemisphere dominant. We found that facial emotion recognition was preserved in the PD group, however, left-affected PD participants had specific impairment in prosodic emotion recognition, especially for sadness. Selective deficits in prosodic emotion recognition suggests that (1) hemispheric effects in emotion recognition may contribute to the impairment of emotional communication in a subset of people with PD and (2) the coordination of neural networks needed to decipher temporally complex social cues may be specifically disrupted in PD. PMID:22564479

  12. Cerebral Contusions and Lacerations

    MedlinePlus

    ... Stretch Additional Content Medical News Cerebral Contusions and Lacerations By James E. Wilberger, MD, Derrick A. Dupre, ... a direct, strong blow to the head. Cerebral lacerations are tears in brain tissue, caused by a ...

  13. Cerebral aneurysm (image)

    MedlinePlus

    ... area within the vessel wall. If a cerebral (brain) aneurysm ruptures, the escaping blood within the brain may cause severe neurologic complications or death. A person who has a ruptured cerebral aneurysm may complain of the sudden onset of "the ...

  14. United Cerebral Palsy

    MedlinePlus

    ... be sure to follow us on Twitter . United Cerebral Palsy UCP educates, advocates and provides support services to ... Partners Merz Logo Sprint Relay Copyright © 2015 United Cerebral Palsy 1825 K Street NW Suite 600 Washington, DC ...

  15. Neuroprotective effect of nobiletin on cerebral ischemia-reperfusion injury in transient middle cerebral artery-occluded rats.

    PubMed

    Yasuda, Nodoka; Ishii, Takayuki; Oyama, Dai; Fukuta, Tatsuya; Agato, Yurika; Sato, Akihiko; Shimizu, Kosuke; Asai, Tomohiro; Asakawa, Tomohiro; Kan, Toshiyuki; Yamada, Shizuo; Ohizumi, Yasushi; Oku, Naoto

    2014-04-22

    Nobiletin, a citrus polymethoxylated flavone, is reported to possess various pharmacological activities such as anticancer, anti-inflammation, and antioxidant effects. Recently, nobiletin was shown to provide therapeutic benefit for the treatment of Alzheimer׳s disease by activating cAMP-response element-binding protein (CREB). In the present study, we investigated whether nobiletin could protect the brain against ischemia-reperfusion (I/R) injury and improve functional outcome in cerebral I/R model rats, since CREB activation is known to protect neuronal cells in cerebral ischemia. Nobiletin was injected twice at 0 and 1h after the start of reperfusion in transient middle cerebral artery occlusion (t-MCAO) rats. Cerebral I/R induced prominent brain damage in the ischemic hemisphere of t-MCAO rat brains; however, nobiletin treatment significantly reduced the infarct volume and suppressed the brain edema. Immunohistochemical and TUNEL staining indicated that nobiletin treatment significantly suppressed neutrophil invasion into the ischemic region and significantly decreased apoptotic brain cell death in ischemic hemisphere, suggesting that the anti-inflammatory effect and anti-apoptotic effect should be regarded as the neuroprotective mechanism of nobiletin. Moreover, nobiletin treatment ameliorated motor functional deficits in the ischemic rats compared with those deficits of the vehicle-treated group. These results indicate that nobiletin is a potential neuroprotectant for the treatment of cerebral I/R injury.

  16. 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

  17. Hemispherical color differences on Pluto and Charon

    NASA Technical Reports Server (NTRS)

    Binzel, Richard P.

    1988-01-01

    Time-resolved multicolor photometric observations of Pluto-Charon mutual events have been used to derive individual colors for these two bodies and to investigate the degree of color differences between their synchronous facing and opposite hemispheres. Pluto is significantly redder than Charon, where direct measurements of the anti-Charon hemisphere of Pluto and the Pluto-facing hemisphere of Charon yield B-V magnitudes of 0.867 + or - 0.008 and 0.700 + or - 0.010, respectively. Both Pluto and Charon are found to have relatively uniform longitudinal color distributions with 1-sigma upper limits of 2 percent and 5 percent, respectively, for any large-scale hemispherical color asymmetries. Thus, a previous suspicion of a significant color asymmetry on Charon is not confirmed. Instead the data may be attributed to a direct detection of polar caps on Pluto.

  18. Hemispherical color differences on pluto and charon.

    PubMed

    Binzel, R P

    1988-08-26

    Time-resolved multicolor photometric observations of Pluto-Charon mutual events have been used to derive individual colors for these two bodies and to investigate the degree of color differences between their synchronous facing and opposite hemispheres. Pluto is significantly redder than Charon, where direct measurements of the anti-Charon hemisphere of Pluto and the Pluto-facing hemisphere of Charon yield B-V magnitudes of 0.867 +/- 0.008 and 0.700 +/- 0.010, respectively. Both Pluto and Charon are found to have relatively uniform longitudinal color distributions with lsigma upper limits of 2% and 5%, respectively, for any large-scale hemispherical color asymmetries. Thus, a previous suspicion of a significant color asymmetry on Charon is not confirmed. Instead the data may be attributed to a direct detection of polar caps on Pluto.

  19. 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...

  20. Hemispheric Asymmetries of the Subauroral Ion Drifts

    NASA Astrophysics Data System (ADS)

    He, F.; Zhang, X.; Wang, W.; Chen, B.

    2015-12-01

    A large database of subauroral ion drifts (SAID) events from DMSP observations from 1987 to 2012 is used to systematically investigate the features of SAID. SAID occurs mostly at ~ 62° / -60° magnetic latitude (MLAT) and ~ 2215 / 2245 magnetic local time (MLT) for geomagnetically quiet conditions and at ~ 58°/ -56° MLAT and ~ 2215 / 2245 MLT for geomagnetically disturbed conditions in the North Hemisphere (NH) / South Hemisphere (SH), respectively. Significant north-south asymmetries in SAID occurrence, shape, and geomagnetic activity variations are found in this statistical study. The latitudinal width of a SAID is larger in the NH than in the SH. An interesting finding of this work is that the SAID occurrence probability peaks have a ~ 180° difference in longitude between the two hemispheres in the geographic coordinates for both geomagnetically quiet and disturbed conditions. The SAID width peaks in almost the same geomagnetic meridian zone with a geomagnetic longitude of ~ 80°-120° in both hemispheres. Significant hemispheric asymmetries and spike signatures with sharpe dips are found in all the latitudinal profiles of the horizontal velocities of SAIDs.The SAID is highly correlated to geomagnetic activity, indicating that the location and evolution of the SAID might be influenced by global geomagnetic activity, auroral dynamics, and the dynamics of ring currents. The hemispheric asymmetries of SAID may possibly be related with the differences of the hemispheric power, the cross-polar cap potential, and the density of region-2 field-aligned currents in the two hemispheres. Detailed investigations will be presented in future.

  1. Homotopic language reorganization in the right hemisphere after early left hemisphere injury.

    PubMed

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

    2012-10-01

    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 controls. Patient groups were carefully matched for IQ, lesion location and size. RH patients' activation across all tasks was greatest in right hemisphere areas homotopic to areas activated by LH and control participants. Differences in right vs. left dominant hemisphere activation were limited to homologous areas typically activated by language tasks, supporting the hypothesis that language localization following transfer to the RH is the mirror-image of localization in the absence of transfer. The similarity of these findings to those in patients with larger, peri-sylvian lesions suggests that these areas in both hemispheres may be uniquely predisposed to subserve various language functions.

  2. Response of Atmospheric Circulation of the Southern Hemisphere to the South Asian High Variation

    NASA Astrophysics Data System (ADS)

    Yang, J.; Wang, C.; Guo, Y.; Zhang, J.

    2014-12-01

    Existing as a strong and steady high pressure system at the top of the troposphere, the South Asia High (SAH) has a significant impact on the weather - climate of the northern hemisphere. However, how the SAH affects the climate of the southern hemisphere remains unclear. In order to find out how atmospheric circulation of the Southern Hemisphere changes in response to the SAH,a numerical simulation model, Community Earth System Model (CESM) , and a set of 40-year reanalyzed data were used. As the SAH is sustained by the surface heating of the Tibetan Plateau (TP), the SAH is weakened with a lower TP. Therefore, two experiments were designed with the altitude of TP set to 50% and 100% of the modern height respectively. The simulation results show that when the SAH is stronger with the modern TP, the subtropical highs over the southern hemisphere and the TP-southern Indian Ocean circulation appear to strengthen. The result from the 40-year ECMWF reanalyzed data analysis shows that the SAH have a significant positive correlation with subtropical highs over the southern hemisphere. It is concluded that with the condition of a stronger SAH, the atmospheric circulation over southern hemisphere strengthens significantly. As a consequence, this climatic change may lead to Antarctica warming and the drying of the southern hemisphere. Keywords: South Asia High; CESM; Climate change; Subtropical high

  3. 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…

  4. Activation and maintenance of peripheral semantic features of unambiguous words after right hemisphere brain damage in adults

    PubMed Central

    Tompkins, Connie A.; Fassbinder, Wiltrud; Scharp, Victoria L.; Meigh, Kimberly M.

    2009-01-01

    Background The right cerebral hemisphere (RH) sustains activation of subordinate, secondary, less common, and/or distantly related meanings of words. Much of the pertinent data come from studies of homonyms, but some evidence also suggests that the RH has a unique maintenance function in relation to unambiguous nouns. In a divided visual field priming study, Atchley, Burgess, and Keeney (1999) reported that only left visual field/RH presentation yielded evidence of continuing activation of peripheral semantic features that were incompatible with the most common image or representation of their corresponding nouns (e.g., rotten for “apple”). Activation for weakly related features that were compatible with the dominant representation (e.g., crunchy) was sustained over time regardless of the visual field/hemisphere of initial stimulus input. Several studies report that unilateral right hemisphere brain damage (RHD) in adults affects the RH’s meaning maintenance function, but this work also has centred on homonyms, and/or more recently metonymic and metaphoric polysemous words. Aims The current investigation examined whether RHD deficits in processing secondary and/or distantly related meanings of words, typically observed in studies of homonyms, would extend to peripheral, weakly related semantic features of unambiguous nouns. Methods & Procedures Participants were 28 adults with unilateral RHD from cerebrovascular accident, and 38 adults without brain damage. Participants listened to spoken sentences that ended with an unambiguous noun. Each sentence was followed by a spoken target phoneme string. Targets included peripheral semantic features of the sentence-final noun that were either compatible or incompatible with the dominant mental images of the noun, and were presented at two intervals after that noun. A lexical decision task was used to gauge both the early activation and maintenance of activation for these weakly related semantic features. Outcomes

  5. Hypothalamic digoxin, hemispheric chemical dominance, and spirituality.

    PubMed

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-03-01

    The isoprenoid pathway was assessed in atheistic and spiritually inclined individuals. The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance has a correlation with spiritual and atheistic tendency. HMG CoA reductase activity, serum digoxin, RBC membrane Na(+)-K+ ATPase activity, serum magnesium, and tyrosine/tryptophan catabolic patterns were assessed in spiritual/atheistic individuals and in those differing hemispheric dominance. In spiritually-inclined individuals, there was increased digoxin synthesis, decreased membrane Na(+)-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine). The pattern in spiritually-inclined individuals correlated with right hemispheric chemical dominance. In atheistic individuals there was decreased digoxin synthesis, increased membrane Na(+)-K+ ATPase activity, decreased tryptophan catabolities (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern in atheistic individuals correlated with that obtained in left hemispheric chemical dominance. Hemispheric chemical dominance and hypothalamic digoxin could regulate the predisposition to spirituality or atheism.

  6. 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.

  7. 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

    2013-02-01

    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

  8. The Divided Visual World Paradigm: Eye Tracking Reveals Hemispheric Asymmetries in Lexical Ambiguity Resolution

    PubMed Central

    Meyer, Aaron M.; Federmeier, Kara D.

    2008-01-01

    Eye tracking was combined with the visual half-field procedure to examine hemispheric asymmetries in meaning selection and revision. In two experiments, gaze was monitored as participants searched a four-word array for a target that was semantically related to a lateralized ambiguous or unambiguous prime. Primes were preceded by a related or unrelated centrally-presented context word. In Experiment 1, unambiguous primes were paired with concordant weakly-related context words and strongly-related targets that were similar in associative strength to discordant subordinate-related context words and dominant-related targets in the ambiguous condition. Context words and targets were reversed in Experiment 2. A parallel study involved the measurement of event-related potentials (ERPs; Meyer, A. M., and Federmeier, K. D., 2007. The effects of context, meaning frequency, and associative strength on semantic selection: Distinct contributions from each cerebral hemisphere. Brain Res. 1183, 91–108). Similar to the ERP findings, gaze revealed context effects for both visual fields/hemispheres when subordinate-related targets were presented: initial gaze revealed meaning activation when an unrelated context was utilized, whereas later gaze also revealed activation in the discordant context, indicating that meaning revision had occurred. However, eye tracking and ERP measures diverged when dominant-related targets were presented: for both visual fields/hemispheres, initial gaze indicated the presence of meaning activation in the discordant context, and, for the right hemisphere, discordant context information actually facilitated gaze relative to unrelated context information. These findings are discussed with respect to the activeness of the task and hemispheric asymmetries in the flexible use of context information. PMID:18585683

  9. Decreased ¹³N-labeled ammonia uptake in the ipsilateral and contralateral hemispheres following carotid endarterectomy.

    PubMed

    Wang, Tao; Wang, Xuemei; He, Yulin; Zhang, Tao; Song, Jianqiang; Bai, Xia; Han, Chunlei

    2015-11-01

    Carotid artery plaques are a leading cause of ischemic stroke, and carotid endarterectomy (CEA) is one of the major treatment approaches for this disease. Changes in cerebral metabolism following CEA remain unclear. The present study aimed to evaluate the effect of cerebral ammonia metabolism following CEA using 13N‑labeled ammonia positron emission tomography (PET) in humans. A total of 20 patients were enrolled in the present study, with a mean age of 59.5 years, comprising 16 males and four females. Of these patients, eight underwent right CEA and 12 underwent left CEA. The rate of carotid artery stenosis was between 50‑69% in six of the patients, between 70‑99% in 11 of the patients and was at 100% (thrombosis) in three of the patients, measured by computerised tomography digital subtraction angiography prior to CEA. 13N‑labeled ammonia (137 MBq) PET scanning was performed prior and subsequent to CEA surgery for each patient. The first ammonia PET scan was performed 1 day prior to CEA, while the second PET scan was performed 1‑4 weeks following CEA. Following injection of 13N‑labeled ammonia, static PET was acquired for 10 min. The region of interest (ROI), covering the major cerebral hemisphere, was selected and ammonia uptake in the ROI was determined in the ipsilateral and contralateral hemispheres. No hyperperfusion syndrome was observed in the patients subsequent to CEA. No significant change in cerebral hemisphere ammonia uptake was observed between the ipsilateral and contralateral hemispheres prior to (ratio =0.98; P>0.01) or following (ratio =1.09; P>0.01) CEA. Ammonia uptake in the ipsilateral and contralateral hemispheres was significantly reduced to 23.2 and 23.5%, respectively, following CEA. Using 13N‑labeled ammonia PET to evaluate cerebral ammonia metabolism following CEA in patients with severe carotid artery stenosis, the present study demonstrated that uptake of ammonia in the ipsilateral and contralateral hemispheres was

  10. Asymmetrical hemisphere activation enhances global-local processing.

    PubMed

    Gable, Philip A; Poole, Bryan D; Cook, Mary S

    2013-12-01

    Decades of research focusing on the neurophysiological underpinnings related to global-local processing of hierarchical stimuli have associated global processing with the right hemisphere and local processing with the left hemisphere. The current experiment sought to expand this research by testing the causal contributions of hemisphere activation to global-local processing. To manipulate hemisphere activation, participants engaged in contralateral hand contractions. Then, EEG activity and attentional scope were measured. Right-hand contractions caused greater relative left-cortical activity than left-hand contractions. Participants were more narrowly focused after left-hemisphere activation than after right-hemisphere activation. Moreover, N1 amplitudes to local targets in the left hemisphere were larger after left-hemisphere activation than after right-hemisphere activation. Consistent with past research investigating hemispheric asymmetry and attentional scope, the current results suggest that manipulating left (right) hemisphere activity enhanced local (global) attentional processing.

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

    PubMed Central

    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. PMID:26644986

  12. Mapping number to space in the two hemispheres of the avian brain.

    PubMed

    Rugani, Rosa; Vallortigara, Giorgio; Regolin, Lucia

    2016-09-01

    Pre-verbal infants and non-human animals associate small numbers with the left space and large numbers with the right space. Birds and primates, trained to identify a given position in a sagittal series of identical positions, whenever required to respond on a left/right oriented series, referred the given position starting from the left end. Here, we extended this evidence by selectively investigating the role of either cerebral hemisphere, using the temporary monocular occlusion technique. In birds, lacking the corpus callosum, visual input is fed mainly to the contralateral hemisphere. We trained 4-day-old chicks to identify the 4th element in a sagittal series of 10 identical elements. At test, the series was identical but left/right oriented. Test was conducted in right monocular, left monocular or binocular condition of vision. Right monocular chicks pecked at the 4th right element; left monocular and binocular chicks pecked at the 4th left element. Data on monocular chicks demonstrate that both hemispheres deal with an ordinal (sequential) task. Data on binocular chicks indicate that the left bias is linked to a right hemisphere dominance, that allocates the attention toward the left hemispace. This constitutes a first step towards understanding the neural basis of number space mapping.

  13. Mapping number to space in the two hemispheres of the avian brain.

    PubMed

    Rugani, Rosa; Vallortigara, Giorgio; Regolin, Lucia

    2016-09-01

    Pre-verbal infants and non-human animals associate small numbers with the left space and large numbers with the right space. Birds and primates, trained to identify a given position in a sagittal series of identical positions, whenever required to respond on a left/right oriented series, referred the given position starting from the left end. Here, we extended this evidence by selectively investigating the role of either cerebral hemisphere, using the temporary monocular occlusion technique. In birds, lacking the corpus callosum, visual input is fed mainly to the contralateral hemisphere. We trained 4-day-old chicks to identify the 4th element in a sagittal series of 10 identical elements. At test, the series was identical but left/right oriented. Test was conducted in right monocular, left monocular or binocular condition of vision. Right monocular chicks pecked at the 4th right element; left monocular and binocular chicks pecked at the 4th left element. Data on monocular chicks demonstrate that both hemispheres deal with an ordinal (sequential) task. Data on binocular chicks indicate that the left bias is linked to a right hemisphere dominance, that allocates the attention toward the left hemispace. This constitutes a first step towards understanding the neural basis of number space mapping. PMID:27246250

  14. 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.

  15. Physiological aging impacts the hemispheric balances of resting state primary somatosensory activities.

    PubMed

    Cottone, Carlo; Tomasevic, Leo; Porcaro, Camillo; Filligoi, Giancarlo; Tecchio, Franca

    2013-01-01

    To hone knowledge of sensorimotor cerebral organization changes with physiological aging, we focused on the primary somatosensory cortical area (S1). S1 neuronal pools (FS_S1) were identified by the functional source separation (FSS) algorithm applied to magnetoencephalographic recordings during median nerve stimulation. Age-dependence of FS_S1 was then studied at rest separately in the left and right hemispheres of 26 healthy, right-handed subjects between the ages of 24 and 95 years. The resting state FS_S1 spectral features changed with increasing age: (1) alpha activity slowed down; (2) total power increased only in the right hemisphere; (3) right>left interhemispheric asymmetry increased in the whole spectrum; (4) spectral entropy increased with age selectively in the left hemisphere. The present FSS-enriched electrophysiological procedure provided measures of resting state hand representation area sensitive to changes with age. Alterations were stronger in the right hemisphere. Relationships between resting state S1 activity and its responsiveness to external stimuli, revealed that the interhemispheric unbalances which emerged with age were conceivably due to an increased excitability within the right thalamocortical circuit impacting left versus right unbalances of spontaneous firing rates and of local inhibitory-excitatory networks.

  16. Cerebral glucose utilization after vasopressin barrel rotation or bicuculline seizures

    SciTech Connect

    Wurpel, J.; Dundore, R.; Bryan, R.; Keil, L.; Severs, W.B.

    1986-03-05

    Intraventricular (ivt) arginine vasopressin (AVP) causes a violent motor behavior termed barrel rotation (BR). AVP-BR is affected by visual/vestibular sensory input and may be related to other CNS motor disorders (seizures). Local cerebral glucose utilization (LCGU) was compared in SD rats during AVP-BR and bicuculline (BIC) seizures. Three groups were used: saline-ivt; AVP-ivt 0.5 ..mu..g; BIC-5.5 mg/kg,sc. /sup 14/C-glucose (40 ..mu..CI iv) was injected 15 sec. after ivt-saline or AVP or onset of BIC seizures. Rats were decapitated 10 min. after /sup 14/C-glucose. Brains were removed and dissected into 19 regions which were digested and glucose uptake quantified by liquid scintillation counting. LCGU was significantly increased in all CNS areas during BIC seizures vs controls (21-92%; p < 0.05 ANOVA). LCGU exhibits variable (upward arrow, downward arrow) changes in discrete areas during AVP-BR (p < .05). Glucose uptake increased in: cortex-olfactory (21%), sensory (9%), motor (8%) cerebellum-rt (13%) and 1t (17%) hemispheres, vermis (6%); pyramidal tract (6%); mesencephalon (5%); and pons (8%). Two areas decreased LCGU during AVP-BR: auditory cortex (-8%) and hippocampus (-11%). AVP-BR exhibits distinct changes in LCGU vs BIC seizures.

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

    PubMed

    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.

  18. Focal cerebral lesions and painting abilities.

    PubMed

    Mazzucchi, Anna; Sinforiani, Elena; Boller, François

    2013-01-01

    Focal lesions such as strokes significantly affect painting production in the vast majority of artists. In particular, painters, when they resume painting, show changes in their painting style. In exceptional cases, there may be an apparent improvement in style, but in most cases, the changes represent nothing short of deterioration. This, however, varies according to the hemisphere affected. Painters with left-hemisphere lesions tend to show an inability to deal adequately with perspective and also tend to use simplified colors with fewer nuances. One often witnesses an evolution toward simpler, often "naïve" techniques, and at times rigid geometric repetitive features. Painters with right-hemisphere lesions also become unable to represent tridimensionality. In addition, their figures are often drawn in very summary fashion, with lack of coordination between volumes and space and a chromatic impoverishment; their main problem, however, is visuospatial, leading to neglect of the left side of the canvas.

  19. Directional information flows between brain hemispheres during presleep wake and early sleep stages.

    PubMed

    Bertini, Mario; Ferrara, Michele; De Gennaro, Luigi; Curcio, Giuseppe; Moroni, Fabio; Vecchio, Fabrizio; De Gasperis, Marco; Rossini, Paolo Maria; Babiloni, Claudio

    2007-08-01

    Neuroscientists' efforts to better understand the underlying processes of human consciousness are growing in a variety of multidisciplinary approaches. Relevant within these are the studies aimed at exploring the physiological substratum of the propagation and reduction of cerebral-namely, corticocortical-communication flows. However, the preferential direction of the information flow between brain hemispheres is as yet largely unknown. It is the aim of the present research to study the communication flows between brain hemispheres, their directionality, and their regional variations across wake-sleep states. A second aim is to investigate the possibility of an association between different brain rhythms and different preferred directions of the information flow. Scalp electroencephalograms (EEGs) were recorded in 10 normal volunteers from wakefulness to early sleep stages (viz., resting wakefulness, sleep stages 2 and 4, and rapid eye movement [REM] of the first sleep cycle). EEG rhythms of interest were delta (1-4 Hz), theta (5-7 Hz), alpha (8-11 Hz), sigma (12-15 Hz), and beta (16-30 Hz). The direction of the interhemispheric information flow was evaluated by computing directed transformation function from these EEG rhythms. Interhemispheric directional flows varied as a function of the state of consciousness (wake and early sleep stages) and in relation to different cerebral areas. Across wake to sleep states, we found that delta and beta rhythms convey interhemispheric signals with opposite directions: preferred right to left hemisphere direction for delta and left to right for beta rhythms. A log correlation confirmed that the trend of low to high EEG frequencies-traditionally associated with an increasing state of vigilance-was significantly related to the direction of the communication flow from the left to right hemisphere. This evidence might open the way for a variety of research lines on different psychophysiological and pathological conditions. PMID

  20. Regional cerebral blood flow during hypoxia-ischemia in immature rats

    SciTech Connect

    Vannucci, R.C.; Lyons, D.T.; Vasta, F.

    1988-02-01

    Immature rats subjected to a combination of unilateral common carotid artery ligation and hypoxia sustain brain damage confined largely to the ipsilateral cerebral hemisphere. To ascertain the extent and distribution of ischemic alterations in the brains of these small animals, we modified the Sakurada technique to measure regional cerebral blood flow using carbon-14 autoradiography. Seven-day-old rats underwent right common carotid artery ligation following which they were rendered hypoxic with 8% O2 at 37 degrees C. Before and during hypoxia, the rat pups received an injection of iodo(/sup 14/C)antipyrine for determination of regional cerebral blood flow. Blood flows to individual structures of the ipsilateral cerebral hemisphere were not influenced by arterial occlusion alone; flows to the contralateral hemisphere and to the brainstem and cerebellum actually increased by 25-50%. Hypoxia-ischemia was associated with decreases in regional cerebral blood flow of the ipsilateral hemisphere such that by 2 hours, flows to subcortical white matter, neocortex, striatum, and thalamus were 15, 17, 34, and 41% of control, respectively. The hierarchy of the blood flow reductions correlated closely with the distribution and extent of ischemic neuronal necrosis. However, unlike the pathologic pattern of this model, the degree of ischemia appeared homogeneous within each brain region. Blood flows to contralateral cerebral hemispheric structures were relatively unchanged from prehypoxic values, whereas flows to the brainstem and cerebellum nearly doubled and tripled, respectively. Thus, ischemia is the predominant factor that determines the topography of tissue injury to major regions of immature rat brain, whereas metabolic factors may influence the heterogeneous pattern of damage seen within individual structures.

  1. Dichotic listening ear preference after childhood cerebral lesions.

    PubMed

    Woods, B T

    1984-01-01

    Patients with unilateral (right or left) nonprogressive cerebral lesions acquired in infancy (before age one) or childhood (ages one to fifteen) were given a dichotic listening test. The two groups of patients with the childhood lesions showed the pattern of ear preference typically seen after hemispheric lesions in adults; loss of right ear preference after left hemisphere (LH) lesions, and enhanced right ear preference after right hemisphere (RH) lesions. The two groups of patients with the very early lesions failed to show any consistent ear preference or to differ from one another in ear preference. It is postulated that this lack of a consistent lesion effect following very early lateralized brain lesions is due to the greater degree of functional reorganization that takes place after such lesions. PMID:6462424

  2. 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…

  3. 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

  4. Hemodynamic and metabolic effects of cerebral revascularization.

    PubMed

    Leblanc, R; Tyler, J L; Mohr, G; Meyer, E; Diksic, M; Yamamoto, L; Taylor, L; Gauthier, S; Hakim, A

    1987-04-01

    Pre- and postoperative positron emission tomography (PET) was performed in six patients undergoing extracranial to intracranial bypass procedures for the treatment of symptomatic extracranial carotid occlusion. The six patients were all men, aged 52 to 68 years. Their symptoms included transient ischemic attacks (five cases), amaurosis fugax (two cases), and completed stroke with good recovery (one case). Positron emission tomography was performed within 4 weeks prior to surgery and between 3 to 6 months postoperatively, using oxygen-15-labeled CO, O2, and CO2 and fluorine-18-labeled fluorodeoxyglucose. Cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rates for oxygen and glucose (CMRO2 and CMRGlu), and the oxygen extraction fraction (OEF) were measured in both hemispheres. Preoperatively, compared to five elderly control subjects, patients had increased CBV, a decreased CBF/CBV ratio, and decreased CMRO2, indicating reduced cerebral perfusion pressure and depressed oxygen metabolism. The CBF was decreased in only one patient who had bilateral carotid occlusions; the OEF, CMRGlu, and CMRO2/CMRGlu and CMRGlu/CBF ratios were not significantly different from control measurements. All bypasses were patent and all patients were asymptomatic following surgery. Postoperative PET revealed decreased CBV and an increased CBF/CBV ratio, indicating improved hemodynamic function and oxygen hypometabolism. This was associated with increased CMRO2 in two patients in whom the postoperative OEF was also increased. The CMRGlu and CMRGlu/CBF ratio were increased in five patients. Changes in CBF and the CMRO2/CMRGlu ratio were variable. One patient with preoperative progressive mental deterioration, documented by serial neuropsychological testing and decreasing CBF and CMRO2, had improved postoperative CBF and CMRO2 concomitant with improved neuropsychological functioning. It is concluded that symptomatic carotid occlusion is associated with altered

  5. 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.

  6. Cerebral Asymmetry of fMRI-BOLD Responses to Visual Stimulation.

    PubMed

    Hougaard, Anders; Jensen, Bettina Hagström; Amin, Faisal Mohammad; Rostrup, Egill; Hoffmann, Michael B; Ashina, Messoud

    2015-01-01

    Hemispheric asymmetry of a wide range of functions is a hallmark of the human brain. The visual system has traditionally been thought of as symmetrically distributed in the brain, but a growing body of evidence has challenged this view. Some highly specific visual tasks have been shown to depend on hemispheric specialization. However, the possible lateralization of cerebral responses to a simple checkerboard visual stimulation has not been a focus of previous studies. To investigate this, we performed two sessions of blood-oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) in 54 healthy subjects during stimulation with a black and white checkerboard visual stimulus. While carefully excluding possible non-physiological causes of left-to-right bias, we compared the activation of the left and the right cerebral hemispheres and related this to grey matter volume, handedness, age, gender, ocular dominance, interocular difference in visual acuity, as well as line-bisection performance. We found a general lateralization of cerebral activation towards the right hemisphere of early visual cortical areas and areas of higher-level visual processing, involved in visuospatial attention, especially in top-down (i.e., goal-oriented) attentional processing. This right hemisphere lateralization was partly, but not completely, explained by an increased grey matter volume in the right hemisphere of the early visual areas. Difference in activation of the superior parietal lobule was correlated with subject age, suggesting a shift towards the left hemisphere with increasing age. Our findings suggest a right-hemispheric dominance of these areas, which could lend support to the generally observed leftward visual attentional bias and to the left hemifield advantage for some visual perception tasks.

  7. Sex differences in right hemisphere tasks.

    PubMed

    Crucian, G P; Berenbaum, S A

    1998-04-01

    We tested the hypothesis that sex differences in spatial ability and emotional perception are due to sex differences in intrahemispheric organization of the right hemisphere. If the right hemisphere is differently organized by sex-primarily specialized for spatial ability in men, but primarily specialized for emotional perception in women-then there should be a negative correlation between spatial ability and emotional perception within sex, and the greatest disparity between abilities should be found in people with characteristic arousal of the right hemisphere. Undergraduate men (N = 86) and women (N = 132) completed tests of Mental Rotation, Surface Development, Profile of Nonverbal Sensitivity, Progressive Matrices, and Chimeric Faces. Although the expected pattern of sex differences was observed, there was no evidence for the hypothesized negative correlation between spatial ability and emotional perception, even after statistical control of general intelligence. PMID:9647685

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. Heat transfer from internally heated hemispherical pools

    SciTech Connect

    Gabor, J.D.; Ellsion, P.G.; Cassulo, J.C.

    1980-01-01

    Experiments were conducted on heat transfer from internally heated ZnSO/sub 4/-H/sub 2/O pools to the walls of hemispherical containers. This experimental technique provides data for a heat transfer system that has to date been only theoretically treated. Three different sizes of copper hemispherical containers were used: 240, 280, 320 mm in diameter. The pool container served both as a heat transfer surface and as an electrode. The opposing electrode was a copper disk, 50 mm in diameter located at the top of the pool in the center. The top surface of the pool was open to the atmosphere.

  13. 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…

  14. 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

  15. Cerebral Laterality and Reading.

    ERIC Educational Resources Information Center

    Mackworth, Jane F.

    Recent research has confirmed that hemispheric patterns of dominance are related to reading skills. Reading is more complex than speech because it includes a visuo-spatial element. In the great majority of people, the left hemisphere deals with speech and sequencing skills. Visual matching of printed words requires the spatial skills of the right…

  16. Optical bedside monitoring of cerebral perfusion: technological and methodological advances applied in a study on acute ischemic stroke

    NASA Astrophysics Data System (ADS)

    Steinkellner, Oliver; Gruber, Clemens; Wabnitz, Heidrun; Jelzow, Alexander; Steinbrink, Jens; Fiebach, Jochen B.; MacDonald, Rainer; Obrig, Hellmuth

    2010-11-01

    We present results of a clinical study on bedside perfusion monitoring of the human brain by optical bolus tracking. We measure the kinetics of the contrast agent indocyanine green using time-domain near-IR spectroscopy (tdNIRS) in 10 patients suffering from acute unilateral ischemic stroke. In all patients, a delay of the bolus over the affected when compared to the unaffected hemisphere is found (mean: 1.5 s, range: 0.2 s to 5.2 s). A portable time-domain near-IR reflectometer is optimized and approved for clinical studies. Data analysis based on statistical moments of time-of-flight distributions of diffusely reflected photons enables high sensitivity to intracerebral changes in bolus kinetics. Since the second centralized moment, variance, is preferentially sensitive to deep absorption changes, it provides a suitable representation of the cerebral signals relevant for perfusion monitoring in stroke. We show that variance-based bolus tracking is also less susceptible to motion artifacts, which often occur in severely affected patients. We present data that clearly manifest the applicability of the tdNIRS approach to assess cerebral perfusion in acute stroke patients at the bedside. This may be of high relevance to its introduction as a monitoring tool on stroke units.

  17. Mitochondrial function and cerebral blood flow responses under unilateral carotid occlusion in rats

    NASA Astrophysics Data System (ADS)

    Livnat, Amir; Barbiro-Michaely, Efrat; Mayevsaky, Avraham

    2009-02-01

    Introduction: Unilateral Carotid Occlusion (UCO) serves as a model of partial cerebral ischemia which mimics clinical situations such as stenosis or atherosclerosis. UCO has known to have slight and merely short-term effects on cerebral hemodynamic and metabolic functions. The aim of this study was to test the effects of UCO compared to bilateral carotid occlusion (BCO) on the responses of the brain to spreading depression (SD). Methods: Rats were monitored up to 24 hours after UCO and BCO using a Multi-Site - Multi-Parametric (MSMP) system, which evaluates mitochondrial function using the NADH fluorometry and CBF using laser Doppler flowmetry. The induction of SD and the exposure to short anoxia served as tools to investigate the effects of UCO and BCO on the brain. Results: UCO and BCO led to a short lasting decrease in CBF and an increase in NADH. During SD waves and short anoxia a hyperemic response occurred, which decreased 24 hours following UCO in the hemisphere ipsilateral to the occluded artery and increased in the contralateral hemisphere. The hyperemic response decreased in both hemispheres 24 hours following BCO. NADH levels during SD waves increased in the hemisphere ipsilateral to the occluded artery following UCO and in both hemispheres following BCO, but remained similar to control levels during short anoxia. Conclusions: UCO leads to long term alterations in cerebral blood supply, which may be detected 24 hours following such occlusion. These changes are minor compared to the effect of BCO and have minimal influence on mitochondrial function.

  18. 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

  19. Cerebral blood flow and CO/sub 2/ reactivity in transient ischemic attacks: comparison between TIAs due to the ICA occlusion and ICA mild stenosis

    SciTech Connect

    Tsuda, Y.; Kimura, K.; Yoneda, S.; Etani, H.; Asai, T.; Nakamura, M.; Abe, H.

    1983-01-01

    Hemispheric mean cerebral blood flow (CBF), together with its CO2 reactivity in response to hyperventilation, was investigated in 18 patients with transient ischemic attacks (TIAs) by intraarterial 133Xe injection method in a subacute-chronic stage of the clinical course. In 8 patients, the lesion responsible for symptoms was regarded as unilateral internal carotid artery (ICA) occlusion, and in 10 patients, it was regarded as unilateral ICA mild stenosis (less than 50% stenosis in diameter). Resting flow values were significantly decreased in the affected hemisphere of TIA due to the ICA occlusion as compared with the unaffected hemisphere of the same patient, regarded as the relative control. It was not decreased in the affected hemisphere of TIA due to the ICA mild stenosis as compared with the control. With respect to the responsiveness of CBF to changes in PaCO2, it was preserved in both TIAs, due to the ICA occlusion and ICA mild stenosis. Vasoparalysis was not observed in either types of TIAs in the subacute-chronic stage. However, in the relationship of blood pressure and CO2 reactivity, expressed as delta CBF(%)/delta PaCO2, pressure-dependent CO2 reactivity as a group was observed with significance in 8 cases of TIA due to the ICA occlusion, while no such relationship was noted in 10 cases of TIA due to the ICA mild stenosis. Moreover, clinical features were different between TIAs due to the ICA occlusion and ICA mild stenosis, i.e., more typical, repeatable TIA (6.3 +/- 3.7 times) with shorter duration (less than 30 minutes) was observed in TIAs due to the ICA mild stenosis, while more prolonged, less repeatable TIA (2.4 +/- 1.4 times) was observed in TIAs due to fixed obstruction of the ICA. From these observations, two different possible mechanisms as to the pathogenesis of TIA might be expected.

  20. The influence of the residual circulation on hemispheric differences in the mesosphere

    NASA Astrophysics Data System (ADS)

    karlsson, B.

    2012-12-01

    The residual circulation in the middle atmosphere has a large impact on the temperature field in the mesosphere. Due to its upward motion at high latitudes in the summer hemisphere, this region is driven towards extremely low temperatures through adiabatic cooling. At the same time, the temperature is well above radiative equilibrium in the winter lower mesosphere, due to down welling and adiabatic heating. This gravity wave driven circulation also supplies the summer mesosphere with water vapor from the lower atmosphere and transports particles from one part of the globe to another. Intriguingly, it is the dynamics in the winter high latitude troposphere and stratosphere that determine the strength of this circulation, even in the summer polar mesopause region. Noctilucent clouds (NLC), which can be thought of as a visible part of this pole-to-pole circulation, can teach us more about how the middle atmosphere behaves. The onset of these mesospheric clouds is affected by the persistence of the winter polar vortex in the same hemisphere as the clouds (intra-hemispheric coupling), whereas the mid-seasonal variability is driven by the stratospheric winter conditions in the opposite hemisphere (inter-hemispheric coupling). In this presentation, the consequences of these coupling processes will be discussed in terms of hemispheric differences observed in the NLC.

  1. Hemispheric processing of mental representations during text comprehension: evidence for inhibition of inconsistent shape information.

    PubMed

    Briner, Stephen W; Virtue, Sandra M; Schutzenhofer, Michael C

    2014-08-01

    To successfully understand a text, readers often mentally represent the shape of an object described in a text (e.g., creating a mental image of a sliced tomato when reading about a tomato on a pizza). However, it is currently unclear how the cerebral hemispheres contribute to these mental images during reading. In the current study, participants were presented with sentences consistent with the shape of an object (i.e., the match condition), sentences inconsistent with the shape of an object (i.e., the mismatch condition), or sentences that did not specify the shape of an object (i.e., the neutral condition). Participants read each sentence and then viewed an image of an object that was quickly presented to either the right visual field-left hemisphere (rvf-LH) or the left visual field-right hemisphere (lvf-RH). Results indicate that when the shape of an object was implicitly described in the text (in Experiment 1), response times for images presented to the rvf-LH were longer in the mismatch condition than in the neutral or match conditions. However, no response time differences were evident in the lvf-RH. When the shape of an object was explicitly described in the text (in Experiment 2), response times were longer in the mismatch condition than in the neutral and match conditions in both hemispheres. Thus, hemispheric involvement in mental representation depends on how explicit information is described in a text. Furthermore, these findings suggest that readers inhibit information that does not match an object׳s shape described in a text.

  2. 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

  3. Transcranial doppler assessment of cerebral flow velocity during perception and recognition of melodies.

    PubMed

    Matteis, M; Silvestrini, M; Troisi, E; Cupini, L M; Caltagirone, C

    1997-07-01

    The role of each cerebral hemisphere in the perception and recognition of musical information is not yet well understood. We studied cerebral blood flow changes during a melody perception task and a melody recognition task. Blood flow velocity in the two middle cerebral arteries of twenty right-handed musically naif volunteers were simultaneously measured by means of bilateral transcranial Doppler ultrasonography during two minutes of passive melody listening and two minutes of a melody recognition task. With respect to baseline values, a bilateral increase of flow velocity occurred in the middle cerebral arteries with a non-significant trend for the right artery during the melody perception task. During the melody recognition task, a significant increase in flow velocity was recorded on the right side with respect to the left side, where a slight simultaneous decrease was found. Our data suggest that melody perception requires bilateral activation of hemispheres and melody recognition mainly an activation of the right hemisphere. This study confirms the ability of transcranial Doppler ultrasonography to correlate artery flow dynamics with selective cerebral activation. PMID:9168166

  4. Retraining in literal alexia: substitution of a right hemisphere perceptual strategy for impaired left hemispheric processing.

    PubMed

    Carmon, A; Gordon, H W; Bental, E; Harness, B Z

    1977-07-01

    An adult patient with literal alexia, agraphia, slight anomia, and dyscalculia due to a left hemisphere infarct showed lack of sequential skills while pattern recognition remained intact. Some words were recognized as patterns, but could not be read phonetically. Therapy concentrated on forming an association of the visual pattern of the complete word with the retained auditory pattern. In this way the patient learned to read several hundred words and short phrases, even as anomia worsened. The patterns learned could not be generalized to noun declension or verb conjugation, or broken into smaller words. This learning process is characteristic of right hemispheric skills which were utilized as left hemispheric functions deteriorated. PMID:617048

  5. 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…

  6. 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…

  7. Practice makes two hemispheres almost perfect.

    PubMed

    Cherbuin, Nicolas; Brinkman, Cobie

    2005-08-01

    Some tasks produce a performance advantage for conditions that require the processing of stimuli in two visual fields compared to conditions where single hemifield processing is sufficient. This advantage, however, disappears with practice. Although no definitive evidence yet exists, there are several possible mechanisms that might lead to improved performance of within- compared to across-hemisphere processing with practice. These include a shift from a more demanding, algorithmic strategy to a less demanding memory-retrieval strategy (e.g., [G. Logan, Toward an instance theory of automatisation. Psych. Rev. 95 (1988) 492-527]), as discussed by Weissman and Compton [D.H. Weissman, R.J. Compton, Practice makes a hemisphere perfect: the advantage of interhemispheric recruitment is eliminated with practice. Laterality, 8 (4) (2003) 361-375], and/or a more generalised practice effect [K. Kirsner, C. Speelman, Skill acquisition and repetition priming: one principle, many processes? J. Exp. Psychol., Learn. Mem. Cogn., 22 (1996) 563-575]. Contrary to Weissman and Compton findings, our results suggest that although single-hemisphere performance improves with practice, bi-hemispheric performance also improves substantially. Furthermore, these effects do not appear to be due to a shift in strategy but rather due to a general practice effect.

  8. 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.

  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. Co-occurrence of Northern and Southern Hemisphere Blocks as Partially Synchronized Chaos.

    NASA Astrophysics Data System (ADS)

    Duane, Gregory S.; Webster, Peter J.; Weiss, Jeffrey B.

    1999-12-01

    Teleconnections between the midlatitudes of the Northern and Southern Hemispheres are diagnosed in National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis data and separately in European Centre for Medium-Range Weather Forecasts reanalysis data. The teleconnections are manifested as a small but significant tendency for blocking to occur simultaneously in the two hemispheres, though at different longitudes and different relative latitudes, during boreal winters over the period 1979-94 in both datasets.One way to explain the correlations between blocking events is as an instance of synchronized chaos, the tendency of some coupled chaotic systems to synchronize, permanently or intermittently, regardless of initial conditions. As the coupling is weakened, the systems no longer synchronize completely, but small correlations between the states of the coupled systems are observed instead. In previous work, such behavior was observed in an idealized coupled-hemisphere model constructed from a midlatitude model due to de Swart, which extended the earlier Charney-DeVore spectral truncation of the barotropic vorticity equation by including a few extra modes. The direct coupling of the two midlatitude systems in the coupled-hemisphere model represented the exchange of Rossby waves through the upper-tropospheric `westerly ducts' in the Tropics.Significant correlations are found between blocking events, which are chaotically timed in each hemisphere considered singly, even without several of the idealizations used in the previous study. In a model modified to include an extended tropical region, the correlations are little affected by attenuation and phase shift of the Rossby waves that couple the two midlatitude systems. Variations in the relative longitudes of topographic features in the two hemispheres leave significant correlations or anticorrelations. The annual cycle, which imposes directionality on the coupling, since the Northern

  11. Hemispheric Coupling: Comparing Dynamo Simulations and Observations

    NASA Astrophysics Data System (ADS)

    Norton, A. A.; Charbonneau, P.; Passos, D.

    2014-12-01

    Numerical simulations that reproduce solar-like magnetic cycles can be used to generate long-term statistics. The variations in north-south hemispheric solar cycle synchronicity and amplitude produced in simulations has not been widely compared to observations. The observed limits on solar cycle amplitude and phase asymmetry show that hemispheric sunspot area production is no more than 20 % asymmetric for cycles 17-23 and that phase lags do not exceed 20 % (or two years) of the total cycle period, as determined from Royal Greenwich Observatory sunspot data. Several independent studies have found a long-term trend in phase values as one hemisphere leads the other for, on average, four cycles. Such persistence in phase is not indicative of a stochastic phenomenon. We compare these observational findings to the magnetic cycle found in a numerical simulation of solar convection recently produced with the EULAG-MHD model. This long "millennium simulation" spans more than 1600 years and generated 40 regular, sunspot-like cycles. While the simulated cycle length is too long (˜40 yrs) and the toroidal bands remain at too high of latitudes (>30°), some solar-like aspects of hemispheric asymmetry are reproduced. The model is successful at reproducing the synchrony of polarity inversions and onset of cycle as the simulated phase lags do not exceed 20 % of the cycle period. The simulated amplitude variations between the north and south hemispheres are larger than those observed in the Sun, some up to 40 %. An interesting note is that the simulations also show that one hemisphere can persistently lead the other for several successive cycles, placing an upper bound on the efficiency of transequatorial magnetic coupling mechanisms. These include magnetic diffusion, cross-equatorial mixing within latitudinally-elongated convective rolls (a.k.a. "banana cells") and transequatorial meridional flow cells. One or more of these processes may lead to magnetic flux cancellation whereby

  12. 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.

  13. 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.

  14. Fatal Massive Cerebral Infarction in a Child after Mild Brain Trauma: A Case Report and Literature Review.

    PubMed

    Calderon-Miranda, Willen Guillermo; Alvis-Miranda, Hernando Raphael; M Rubiano, Andres; Moscote-Salazar, Luis Rafael

    2014-04-01

    Traumatic brain injury is a common entity. However cerebral infarction in infants is a rare entity while the diagnosis of this pathology in the pediatric population is usually difficult. The mild head trauma is rarely accompanied by intracranial injury and even less, with cerebral infarction. We herein report the first case of cerebral infarction after a mild brain trauma in a 2-year-old Latin-American male patient, in which brain computed tomography (CT) scan was performed on the first day of the accident, showed right hemispheric cerebral ischemia compromising the fronto-parieto-occipital region. Conservative management was established. The patient died at day 5. So Brain CT scan may be beneficial to reveal any hemispheric infarction due to a probable mass effect.

  15. Fatal Massive Cerebral Infarction in a Child after Mild Brain Trauma: A Case Report and Literature Review

    PubMed Central

    Calderon-Miranda, Willen Guillermo; Alvis-Miranda, Hernando Raphael; M. Rubiano, Andres; Moscote-Salazar, Luis Rafael

    2014-01-01

    Traumatic brain injury is a common entity. However cerebral infarction in infants is a rare entity while the diagnosis of this pathology in the pediatric population is usually difficult. The mild head trauma is rarely accompanied by intracranial injury and even less, with cerebral infarction. We herein report the first case of cerebral infarction after a mild brain trauma in a 2-year-old Latin-American male patient, in which brain computed tomography (CT) scan was performed on the first day of the accident, showed right hemispheric cerebral ischemia compromising the fronto-parieto-occipital region. Conservative management was established. The patient died at day 5. So Brain CT scan may be beneficial to reveal any hemispheric infarction due to a probable mass effect. PMID:27162874

  16. 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…

  17. 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

  18. 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 ...

  19. Hemihyperhidrosis in cerebral infarction.

    PubMed

    Faruqi, Shoaib; Redmond, Gemma; Ram, Pusbar; Owens, Val B; Sangster, Graeme; Barrett, James A

    2004-09-01

    Increased sweating on the hemiparetic side in cerebral infarcts is not a common clinical finding. The onset, severity and duration of symptoms can vary. The structural lesion responsible for this is a subject of conjecture. We present the case of a 66-year-old man who developed hemihyperhidrosis secondary to a cerebral infarct. PMID:15315923

  20. Effect of dietary β carotene on cerebral aneurysm and subarachnoid haemorrhage in the brain apo E-/- mice.

    PubMed

    Gopal, K; Nagarajan, P; Raj, T Avinash; Jahan, P; Ganapathy, H S; Mahesh Kumar, M J

    2011-10-01

    Atherosclerosis will lead to stenosis/occlusion in the lumen of various arteries of living body. This can lead various conditions including myocardial infarction, cerebral infarction/aneurysm and peripheral artery disease. Ang II is believed to be an important regulatory peptide involved in maintaining cardiovascular homeostasis and pathogenesis of various cardiovascular diseases. Matrix metalloproteinase's (MMPs), adhesion molecules and plasminogen systems are involved in the inflammatory reaction of various blood vessels as well as pathogenesis of cerebro vasuclar disease in apo E(-/-) mice during angiotensin II injection. The present study analyses the role of ang II in development of cerebral aneurysm and also evaluated the mRNA levels of MMPs, adhesion molecules, plasminogen systems and peroxisome proliferators-associated receptors in the brain of apo E(-/-) mouse during the progression of cerebral aneurysm and ischemic conditions. Also, this study evaluates the role of dietary β carotene on cerebrovascular disease. Serum total cholesterol (TC), Low density lipoprotein (LDL) and triglyceride (TG) levels were significantly increased in angiotensin II treated animals and further β carotene supplementation reduces TC but does not affect the triglyceride and LDL levels. Circulating levels of macrophages were significantly increased in angiotensin treated animals and further beta carotene supplementation significantly reduced the circulating macrophages. Cerebro meningeous aneurysm, subarachnoid haemorrhage, multiple foci of infarction, necrosis and infiltration of inflammatory cells were observed in the cerebral hemispheres of ang II treated animals, however, infarction size were reduced and no aneurysm, inflammatory foci was observed in β carotene treated animals. Real time analysis showed down regulation of mRNA levels of MMP 2, uPA, PAI, PPAR-A, MCSF1 and up regulation of tPA and MCP-1 in the brain during the progression of cerebral aneurysm and β carotene

  1. 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

  2. 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. PMID:26766393

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Unilateral cerebral ischemia inhibits optomotor responses of the ipsilateral eye in mice.

    PubMed

    Xiao, Jian; Zhou, Xiantiang; Jiang, Tian; Zhi, Zhi-Na; Li, Qu; Qu, Jia; Chen, Jie-Guang

    2012-06-01

    A reduction in blood flow to the brain causes stroke and damage to neuronal networks. Cerebral ischemia is frequently associated with loss of visual functions. Because retinal and small cerebral vessels are vulnerable to similar risk factors, the loss of vision could result from concurrent retinal ischemia, and it is not clear if visual functions may be inhibited by cerebral ischemia directly. In this study, the distal middle cerebral artery in the right hemisphere of mice was occluded to produce unilateral cerebral ischemia and subsequent infarction. The layer V neurons expressing YFP in transgenic yellow fluorescent protein in transgenic B6.Cg-Tg(Thy1-YFPH)2Jrs/J mice disappeared in the motor and somatosensory cortex, but not in the visual area. The latencies of flash visual evoked potential recorded from two hemispheres were imbalanced, but did not differ markedly from the latencies recorded in controls. However, the optomotor responses of the ipsilateral eye were significantly reduced by 48 h after occlusion. Our results suggest that focused cerebral ischemia may inhibit ipsilateral eye movement in the absence of damage to the visual cortex. This study may provide a platform for further investigation of the relationship between cortical ischemia and visual function. PMID:22744825

  9. 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.

  10. Hemispherical sky simulator for daylighting model studies

    NASA Astrophysics Data System (ADS)

    Selkowitz, S.

    1981-07-01

    The design of a 24 foot diameter hemispherical sky simulator is described. A facility in which large models is tested, which is suitable for research, teaching, and design which could provide a uniform sky, an overcast sky, and several clear sky luminance distributions, as well as accommodating an artificial sun was produced. Initial operating experience with the facility is described, the sky simulator capabilities are reviewed, and its strengths and weaknesses relative to outdoor modelling tests are discussed.

  11. 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.

  12. 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. PMID:25191257

  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. 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).…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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

  1. 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.

  2. 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.

  3. Topography of somatosensory processing: cerebral lateralization and focused attention.

    PubMed

    Meador, K J; Allison, J D; Loring, D W; Lavin, T B; Pillai, J J

    2002-03-01

    Healthy dextrals underwent fMRI during a task of graphesthesia requiring detection of any number written consecutively from an otherwise random number sequence. Test conditions included (1) focus on unilateral right hand stimuli, (2) focus on unilateral left hand stimuli, (3) focus on right hand only during bilateral hand stimulation, (4) focus on left hand only during bilateral hand stimulation, and (5) rest. Attention to unilateral hand stimulation produced bihemispheric activation with minimal or no activation of ipsilateral primary sensorimotor region. Attention to unilateral left hand stimuli resulted in more activation than attention to unilateral right hand stimuli. Stimulation of the nonattended hand activated the contralateral somatosensory area, but to a lesser spatial extent than attended stimuli. Comparing focused attention to the left versus right side during identical sensory inputs (i.e., bilateral hand stimulation), focused attention to the right hand increased activation in the left somatosensory region, but focused attention to the left hand increased activation in both cerebral hemispheres. Thus, focused attention to unilateral somatosensory stimuli produces bilateral cerebral activation, but the increase in blood flow is greater in the contralateral hemisphere. Unattended stimuli activate the contralateral primary somatosensory area. Left/right asymmetries were demonstrated consistent with cerebral lateralization.

  4. A case of chronic cerebral paragonimiasis westermani.

    PubMed

    Kang, S Y; Kim, T K; Kim, T Y; Ha, Y I; Choi, S W; Hong, S J

    2000-09-01

    We report a chronic cerebral paragonimiasis from a 41-year-old Korean man who complains a headache and weakness of left motor neuron components. Magnetic resonance images of the brain revealed conglomerates of multiple ring-like enhancements in temporo-occipital and frontal lobes of the right hemisphere. An intradermal test for paragonimiasis westermani was positive. The patient was born near an endemic area of paragonimiasis and used to eat boiled or grilled freshwater crayfish in his childhood. Nodules in the brain were resected through craniotomies. The eggs of P. westermani were identified pathologically and parasitologically in the calcified necrotic lesions. Examinations on sputum and fecal specimens for the eggs of P. westermani were shown to be negative and a chest radiograph was normal. It is presumed that the brain lesions were formed by P. westermani approximately 30 years ago.

  5. 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.

  6. 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

  7. Right-hemisphere preponderance of responses to painful CO2 stimulation of the human nasal mucosa.

    PubMed

    Hari, R; Portin, K; Kettenmann, B; Jousmäki, V; Kobal, G

    1997-08-01

    We recorded whole-scalp cerebral magnetic fields from healthy adults to painful CO2 pulses (duration 200 ms, concentration 65-90%), led to the left or right nostril once every 20 or 30 s. The stimuli were embedded in a continuous airflow (140 ml/s, 36.5 degrees C, relative humidity 80%) to prevent alterations in the mechanical and thermal conditions of the nasal mucosa. The recording passband was 0.03-90 Hz and 16 single responses were averaged per run. Five out of the 9 subjects showed replicable and artifact-free responses 280-400 ms after stimulus onset. The main responses originated close to the second somatosensory cortex (SII), most frequently in the right hemisphere, and also in the rolandic areas, mostly on the left. The signals were considerably stronger over the right than the left frontotemporal region, with a right-to-left ratio of 2.3 for areal mean signal amplitudes calculated across 16 channels, for both left and right nostril stimuli. Air puffs delivered to the nasal mucosa resulted in a trend for right-hemisphere dominant responses, but responses to air puff stimulation of the lip and the forehead were symmetric. The right-hemisphere dominance of the SII responses may be associated with the painful, and thus unpleasant, nature of the CO2 stimulus, thereby suggesting involvement of the right hemisphere in emotional/motivational aspects of trigeminal pain, in agreement with the role of the trigeminal pathways as a general warning system.

  8. 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.

  9. A case of iatrogenic cerebral infarction demonstrated by postmortem cerebral angiography.

    PubMed

    Tajima, Yutaka; Takagi, Rie; Kominato, Yoshihiko; Kuwayama, Naoya

    2007-11-01

    A 37-year-old man with a meningioma compressing the right frontal lobe underwent preoperative embolization of the feeding vessels from the right meningeal artery. Although the first challenge was apparently successful, an excess amount of embolization agent was accidentally injected during the next procedure. X-ray monitoring demonstrated flow of contrast medium into the right internal carotid, anterior and middle cerebral arteries, and then the patient suddenly developed left hemiparesis, nausea, and deep coma. He died 48 days after the embolization treatment without improvement of the coma. A medicolegal autopsy was performed to determine whether malpractice had occurred during the embolization procedure. An internal examination demonstrated massive necrosis of the cerebral hemispheres and lobar pneumonia with abscess in the lungs. Due to the extensive brain necrosis, it was impossible to carry out ordinary macroscopic examination to identify the precise site of the craniocerebral vessel occlusion. Postmortem angiography was therefore performed, and this successfully revealed occlusion of the right internal carotid artery. In this case, postmortem angiography played a key role in identification of the intracranial vascular lesion that was responsible for the iatrogenic cerebral infarction.

  10. Hemispheric specialization for linguistic processing of sung speech.

    PubMed

    Yelle, Serena K; Grimshaw, Gina M

    2009-02-01

    The two hemispheres of the brain play complementary roles in song perception, with the left hemisphere specialized for processing the linguistic aspects of song and the right hemisphere specialized for the processing of melody. However, very little is known about how language and melody interact. The present study tested the hypothesis that right hemisphere linguistic processing would be facilitated by the presence of melody. In a dichotic listening paradigm, participants (8 men, 43 women) performed a linguistic task while listening to spoken or sung speech. Contrary to the hypothesis, left hemisphere specialization for linguistic processing was identical whether the sentences were spoken or sung.

  11. Loss of left-sided volitional movements caused by a combined lesion of the corpus callosum and right hemisphere:'initiation pseudohemiakinesia'.

    PubMed

    Yokoyama, K; Hasegawa, C; Kameyama, M

    2000-01-01

    We report a right-handed patient who showed a marked loss of unilateral volitional movements of the left limbs after the onset of a cerebral infarction in the combined territories of the right anterior and middle cerebral arteries. The same limbs retained their mobility in acts requiring bilateral sides of the body. This left-sided abnormal behavior resembled motor neglect resulting from lateralized brain damage. Behavioral and neuroradiological findings presented by this patient, however, suggested that callosal disconnection was definitely involved in this symptomatology. We postulate that in this patient, the diseased right hemisphere could no longer initiate movements of the left limbs despite its potential ability to realize them, and that the injured callosum prevented the intact left hemisphere from initiating unilateral voluntary movements of the left limbs. We suggest that this so far undescribed symptomatology be called 'initiation pseudohemiakinesia' in order to be distinguished from other rare forms of unilateral voluntary movements like motor neglect, extinction or directional hypokinesia.

  12. A case of adult moyamoya disease showing progressive angiopathy on cerebral angiography.

    PubMed

    Shirane, R; Mikawa, S; Ebina, T

    1999-09-01

    In moyamoya disease, progression of carotid occlusive lesion in an adult patient is very rare. We report a case of adult moyamoya disease with acute angiographical stage progression and hemodynamic deterioration. A 56-year-old female complaining of left motor weakness visited our department. On MRI, infarct lesion was found in the right white matter. On cerebral angiography, occlusive lesions in the bilateral internal carotid arterial siphons and moyamoya vessels were found. The right side was stage V and the left side was stage III. On IMP-SPECT, decreased cerebral hemodynamic reserve of the right cerebral hemisphere was found. In this patient, right STA-MCA anastomosis was performed. After operation, she became possible to walk and discharged to home. Five months after operation, good collateral formation and improvement of hemodynamic reserve in the right hemisphere were found. However, on left carotid arteriography, the anterior and middle cerebral arteries were only slightly imaged, and the disease state progressed to stage IV. In addition, decreased blood flow and hemodynamic reserve were appeared in the left hemisphere.

  13. Acquired Cerebral Trauma: Epilogue.

    ERIC Educational Resources Information Center

    Bigler, Erin D., Ed.

    1988-01-01

    The article summarizes a series of articles concerning acquired cerebral trauma. Reviewed are technological advances, treatment, assessment, potential innovative therapies, long-term outcome, family impact of chronic brain injury, and prevention. (DB)

  14. Chikungunya fever: Atypical and lethal cases in the Western hemisphere

    PubMed Central

    Torres, Jaime R.; Leopoldo Códova G.; Castro, Julio S.; Rodríguez, Libsen; Saravia, Víctor; Arvelaez, Joanne; Ríos-Fabra, Antonio; Longhi, María A.; Marcano, Melania

    2014-01-01

    A large epidemic of Chikungunya fever currently affects the Caribbean, Central and South America. Despite a high number of reported cases, little is known on the occurrence of severe clinical complications. We describe four Venezuelan patients with a severe and/or lethal course who exhibit unusual manifestations of the disease. Case 1 describes a 75 year-old man with rapid onset of septic shock and multi-organ failure. Cases 2 and 3 describe two patients with rapid aggressive clinical course who developed shock, severe purpuric lesions and a distinct area large of necrosis in the nasal region. Case 4 depicts a splenectomized woman with shock, generalized purpuric lesions, bullous dermatosis and acronecrosis of an upper limb. Chikungunya fever in the Western hemisphere may also associate with atypical and severe manifestations. Some patients experience a life-threatening, aggressive clinical course, with rapid deterioration and death due to multisystem failure. PMID:26793440

  15. Hemispheric snow water equivalent: The need for a synergistic approach

    NASA Astrophysics Data System (ADS)

    Tedesco, Marco; Derksen, Chris; Pulliainen, Jouni

    2012-07-01

    Snow plays a crucial role in climatological and hydrological processes, and it is a key factor in modulating energy, water, and carbon budgets. The optically bright snow-covered surface regulates the amount of solar radiation absorbed by the Earth, which influences regional energy budgets. Snow water equivalent (SWE), the amount of water stored within the snowpack, has wide-ranging effects: playing a critical role in the management of water resources and hydropower production, influencing the soil temperature through thermally insulating properties, and affecting the ability of rangifers (i.e., caribou) to efficiently forage for food. These are some examples of the importance of estimating snow depth and SWE across regional and hemispheric scales.

  16. Focal cerebral ischaemia in the rat: 2. Regional cerebral blood flow determined by (14C)iodoantipyrine autoradiography following middle cerebral artery occlusion

    SciTech Connect

    Tamura, A.; Graham, D.I.; McCulloch, J.; Teasdale, G.M.

    1981-01-01

    Local cerebral blood flow has been measured by quantitative autoradiography, employing (14C)iodoantipyrine as tracer, in rats killed half an hour after occlusion of the middle cerebral artery. The results were compared with pattern of local cerebral blood flow (CBF) in sham-operated rats and with neuropathological findings. In every animal there was a profound reduction (to 13% of control levels)in blood flow in the neocortex previously by the occluded artery. The level of blood flow in the areas in which ischaemic brain damage occurred was 0.24 +/- 0.03 ml g-1 min-1 (mean +/- SEM). this level of CBF is considerably greater than that reported following a similar surgical procedure in cats and primates. Moderate reductions in blood flow were also seen outside the territory of the occluded artery and in parts of the opposite hemisphere. Absolute increases in blood flow (hyperaemia) were seen only in the substantia nigra and globus pallidus ipsilateral to the occlusion. It is of the middle cerebral artery are reflections of alterations in neuronal function and metabolic activity secondary to the ischaemic lesion.

  17. Sonic hedgehog signaling regulates mode of cell division of early cerebral cortex progenitors and increases astrogliogenesis

    PubMed Central

    Araújo, Geissy L. L.; Araújo, Jessica A. M.; Schroeder, Timm; Tort, Adriano B. L.; Costa, Marcos R.

    2014-01-01

    The morphogen Sonic Hedgehog (SHH) plays a critical role in the development of different tissues. In the central nervous system, SHH is well known to contribute to the patterning of the spinal cord and separation of the brain hemispheres. In addition, it has recently been shown that SHH signaling also contributes to the patterning of the telencephalon and establishment of adult neurogenic niches. In this work, we investigated whether SHH signaling influences the behavior of neural progenitors isolated from the dorsal telencephalon, which generate excitatory neurons and macroglial cells in vitro. We observed that SHH increases proliferation of cortical progenitors and generation of astrocytes, whereas blocking SHH signaling with cyclopamine has opposite effects. In both cases, generation of neurons did not seem to be affected. However, cell survival was broadly affected by blockade of SHH signaling. SHH effects were related to three different cell phenomena: mode of cell division, cell cycle length and cell growth. Together, our data in vitro demonstrate that SHH signaling controls cell behaviors that are important for proliferation of cerebral cortex progenitors, as well as differentiation and survival of neurons and astroglial cells. PMID:24653675

  18. 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

  19. Effect of intracarotid injection of iopamidol on local cerebral glucose utilization in rat brain.

    PubMed

    d'Avella, D; Cicciarello, R; Albiero, F; Piscitelli, G; Fiori, M G; Mesiti, M; Princi, P; d'Aquino, S

    1989-01-01

    We assessed, by means of the [14C]-2-deoxy-D-glucose autoradiography method, the effect of intracarotid injection of a nonionic, low-osmolar contrast medium (iopamidol) on local cerebral glucose utilization in the rat brain. Contrast medium was injected at 20 degrees C and at 37 degrees C, and the relative changes in local cerebral glucose utilization were measured. At 20 degrees C the viscosity of the contrast agent was about twice that of the same solution at 37 degrees C, and resulted in a statistically significant increase in local cerebral glucose utilization in the hemisphere ipsilateral to the side of intracarotid infusion. Saline control studies showed that the metabolic change was not related to either the solution temperature or the osmolality. These findings suggest that increased viscosity of a contrast medium may contribute to its neurotoxic effects during cerebral angiography, hence emphasizing the importance of preheating contrast material to avoid adverse reactions.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. Phenological Changes in the Southern Hemisphere

    PubMed Central

    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

  5. Walter Baade and the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Osterbrock, D. E.

    1993-12-01

    The inception of the European Southern Observatory is generally traced to Walter Baade's discussions with Jan Oort during his visit to Leiden in the spring of 1953. However, these discussions had certainly been underway between them previously, during Oort's visit to Pasadena in early 1952. Furthermore, Baade's great interest in southern-hemisphere astronomy and his strong desire to observe there can be traced far back in his career. In 1927, after his return to Germany from a year in the U.S. under a Rockefeller fellowship, Baade reported that his country had no chance to catch up with American astronomy in the northern hemisphere. He advocated moving the Hamburg 1-meter reflector to the southern hemisphere to get in ahead of the U.S. with an effective telescope there. Baade emphasized the research that could be done on high-luminosity and variable stars in the Magellanic Clouds. Later, after he had joined the Mount Wilson staff, his early attempts to locate the center of our Galaxy and globular clusters near it (in 1937) and his observational study (with Edwin Hubble) of the Sculptor and Fornax dwarf galaxies (in 1939) re-emphasized to him the need for a southern observatory. During and soon after World War II he made many suggestions on a search for ``cluster-type variables'' in the Magellanic Clouds to Enrique Gaviola, director of the new 1.5-meter Bosque Alegre reflector in Argentina. Baade wanted to go there to observe with it himself, but his German citizenship prevented him from leaving the U.S.. Finally, in the last year of his life, he was able to observe NGC 6522 (the globular cluster in ``his'' window), with the Mount Stromlo 1.9-meter reflector.

  6. Sequential processing in hemispheric word recognition: the impact of initial letter discriminability on the OUP naming effect.

    PubMed

    Lindell, Annukka K; Nicholls, Michael E R; Kwantes, Peter J; Castles, Anne

    2005-05-01

    The cerebral hemispheres have been proposed to engage different word recognition strategies: the left hemisphere implementing a parallel, and the right hemisphere, a sequential, analysis. To investigate this notion, we asked participants to name words with an early or late orthographic uniqueness point (OUP), presented horizontally to their left (LVF), right (RVF), or both fields of vision (BVF). Consistent with past foveal research, Experiment 1 produced a robust facilitatory effect of early OUP for RVF/BVF presentations, indicating the presence of sequential processes in lexical retrieval. The effect was absent for LVF trials, which we argue results from the disadvantaged position of initial letters of words presented in the LVF. To test this proposition, Experiment 2 assessed the discriminability of various letter positions in the visual fields using a bar-probe task. The obtained error functions highlighted the poor discriminability of initial letters in the LVF and latter letters in the RVF. To confirm that this asymmetry in initial letter acuity was responsible for the absent OUP effect for LVF presentations, Experiment 3 replicated Experiment 1 using vertical stimulus presentations. Results indicated a marked facilitatory effect of early OUP across visual fields, supporting our contention that the lack of OUP effect for LVF presentations in Experiment 1 resulted from poor discriminability of the initial letters. These findings confirm the presence of sequential processes in both left and right hemisphere word recognition, casting doubt on parallel models of word processing.

  7. Circular single domains in hemispherical Permalloy nanoclusters

    SciTech Connect

    Araujo, Clodoaldo I. L de Fonseca, Jakson M.; Sinnecker, João P.; Delatorre, Rafael G.; Garcia, Nicolas; Pasa, André A.

    2014-11-14

    We have studied ferromagnetic Permalloy clusters obtained by electrodeposition on n-type silicon. Magnetization measurements reveal hysteresis loops almost independent on temperature and very similar in shape to those obtained in nanodisks with diameter bigger than 150 nm. The spin configuration for the ground state, obtained by micromagnetic simulation, shows topological vortices with random chirality and polarization. This behavior in the small diameter clusters (∼80 nm) is attributed to the Dzyaloshinskii-Moriya interaction that arises in its hemispherical geometries. This magnetization behavior can be utilized to explain the magnetoresistance measured with magnetic field in plane and out of sample plane.

  8. 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.

  9. The neural correlates of affect reading: an fMRI study on faces and gestures.

    PubMed

    Prochnow, D; Höing, B; Kleiser, R; Lindenberg, R; Wittsack, H-J; Schäfer, R; Franz, M; Seitz, R J

    2013-01-15

    As complex social beings, people communicate, in addition to spoken language, also via nonverbal behavior. In social face-to-face situations, people readily read the affect and intentions of others in their face expressions and gestures recognizing their meaning. Importantly, the addressee further has to discriminate the meanings of the seen communicative motor acts in order to be able to react upon them appropriately. In this functional magnetic resonance imaging study 15 healthy non-alexithymic right-handers observed video-clips that showed the dynamic evolution of emotional face expressions and gestures evolving from a neutral to a fully developed expression. We aimed at disentangling the cerebral circuits related to the observation of the incomplete and the subsequent discrimination of the evolved bodily expressions of emotion which are typical for everyday social situations. We show that the inferior temporal gyrus and the inferior and dorsal medial frontal cortex in both cerebral hemispheres were activated early in recognizing faces and gestures, while their subsequent discrimination involved the right dorsolateral frontal cortex. Interregional correlations showed that the involved regions constituted a widespread circuit allowing for a formal analysis of the seen expressions, their empathic processing and the subjective interpretation of their contextual meanings. Right-left comparisons revealed a greater activation of the right dorsal medial frontal cortex and the inferior temporal gyrus which supports the notion of a right hemispheric dominance for processing affective body expressions. These novel data provide a neurobiological basis for the intuitive understanding of other people which is relevant for socially appropriate decisions and intact social functioning.

  10. The neural correlates of affect reading: an fMRI study on faces and gestures.

    PubMed

    Prochnow, D; Höing, B; Kleiser, R; Lindenberg, R; Wittsack, H-J; Schäfer, R; Franz, M; Seitz, R J

    2013-01-15

    As complex social beings, people communicate, in addition to spoken language, also via nonverbal behavior. In social face-to-face situations, people readily read the affect and intentions of others in their face expressions and gestures recognizing their meaning. Importantly, the addressee further has to discriminate the meanings of the seen communicative motor acts in order to be able to react upon them appropriately. In this functional magnetic resonance imaging study 15 healthy non-alexithymic right-handers observed video-clips that showed the dynamic evolution of emotional face expressions and gestures evolving from a neutral to a fully developed expression. We aimed at disentangling the cerebral circuits related to the observation of the incomplete and the subsequent discrimination of the evolved bodily expressions of emotion which are typical for everyday social situations. We show that the inferior temporal gyrus and the inferior and dorsal medial frontal cortex in both cerebral hemispheres were activated early in recognizing faces and gestures, while their subsequent discrimination involved the right dorsolateral frontal cortex. Interregional correlations showed that the involved regions constituted a widespread circuit allowing for a formal analysis of the seen expressions, their empathic processing and the subjective interpretation of their contextual meanings. Right-left comparisons revealed a greater activation of the right dorsal medial frontal cortex and the inferior temporal gyrus which supports the notion of a right hemispheric dominance for processing affective body expressions. These novel data provide a neurobiological basis for the intuitive understanding of other people which is relevant for socially appropriate decisions and intact social functioning. PMID:22981562

  11. EEG correlates of cerebral engagement in reading tasks.

    PubMed

    Bizas, E; Simos, P G; Stam, C J; Arvanitis, S; Terzakis, D; Micheloyannis, S

    1999-01-01

    This study evaluated the utility of electroencephalographic (EEG) measures as indices of regional cerebral engagement activation during reading in neurologically intact adult volunteers. EEG was recorded from 16 scalp locations as participants performed four visual detection tasks designed to tap into increasingly more complex operations regularly involved in reading, namely visual-spatial, orthographic, phonological, and semantic. EEG records were quantified using power spectrum measures in four frequency bands (delta, theta, alpha, beta1, and beta2), in addition to a non-linear estimate of signal complexity (prediction error). Results showed that (1) changes in spectral power between pairs of reading tasks, and (2) regional variations in EEG measures for each task, were restricted to signals recorded over the left hemisphere. These findings are in agreement with knowledge regarding left hemisphere involvement in higher level component processes of reading.

  12. Effects of characterological anxiety and situational arousal on the solving of a color-word interference task: hemispheric processing implications.

    PubMed

    Newman, J P

    1990-05-01

    Stroop color-word stimuli permit examination of relative hemispheric contributions to cognition. Subjects of varying trait anxiety levels underwent situational arousal manipulations. Discrete color-word stimuli were projected to the visual half-fields; motor matching responses were made. Trait anxiety affected left-hemisphere activation. Responding was faster and more accurate for moderate than low trait anxiety; at high levels, the left hemisphere became overactivated and inefficient. Situational arousal facilitated right-hemisphere performance; latencies were shorter and accuracy increased in the aroused compared with the relaxed condition. Situational arousal interacted with trait anxiety; highly trait-anxious subjects had longer latencies and decreased accuracy when relaxed than when aroused. A paradoxical effect of trait anxiety is rigidity and stereotypy of cognitive functioning, impairing ability to assume appropriate alternative cognitive modes.

  13. 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.

  14. Distinct hemispheric specializations for native and non-native languages in one-day-old newborns identified by fNIRS.

    PubMed

    Vannasing, Phetsamone; Florea, Olivia; González-Frankenberger, Berta; Tremblay, Julie; Paquette, Natacha; Safi, Dima; Wallois, Fabrice; Lepore, Franco; Béland, Renée; Lassonde, Maryse; Gallagher, Anne

    2016-04-01

    This study assessed whether the neonatal brain recruits different neural networks for native and non-native languages at birth. Twenty-seven one-day-old full-term infants underwent functional near-infrared spectroscopy (fNIRS) recording during linguistic and non-linguistic stimulation. Fourteen newborns listened to linguistic stimuli (native and non-native language stories) and 13 newborns were exposed to non-linguistic conditions (native and non-native stimuli played in reverse). Comparisons between left and right hemisphere oxyhemoglobin (HbO2) concentration changes over the temporal areas revealed clear left hemisphere dominance for native language, whereas non-native stimuli were associated with right hemisphere lateralization. In addition, bilateral cerebral activation was found for non-linguistic stimulus processing. Overall, our findings indicate that from the first day after birth, native language and prosodic features are processed in parallel by distinct neural networks. PMID:26851309

  15. Inter-hemispheric temperature variability over the past millennium

    NASA Astrophysics Data System (ADS)

    Neukom, Raphael; Gergis, Joëlle; Karoly, David J.; Wanner, Heinz; Curran, Mark; Elbert, Julie; González-Rouco, Fidel; Linsley, Braddock K.; Moy, Andrew D.; Mundo, Ignacio; Raible, Christoph C.; Steig, Eric J.; van Ommen, Tas; Vance, Tessa; Villalba, Ricardo; Zinke, Jens; Frank, David

    2014-05-01

    The Earth's climate system is driven by a complex interplay of internal chaotic dynamics and natural and anthropogenic external forcing. Recent instrumental data have shown a remarkable degree of asynchronicity between Northern Hemisphere and Southern Hemisphere temperature fluctuations, thereby questioning the relative importance of internal versus external drivers of past as well as future climate variability. However, large-scale temperature reconstructions for the past millennium have focused on the Northern Hemisphere, limiting empirical assessments of inter-hemispheric variability on multi-decadal to centennial timescales. Here, we introduce a new millennial ensemble reconstruction of annually resolved temperature variations for the Southern Hemisphere based on an unprecedented network of terrestrial and oceanic palaeoclimate proxy records. In conjunction with an independent Northern Hemisphere temperature reconstruction ensemble, this record reveals an extended cold period (1594-1677) in both hemispheres but no globally coherent warm phase during the pre-industrial (1000-1850) era. The current (post-1974) warm phase is the only period of the past millennium where both hemispheres are likely to have experienced contemporaneous warm extremes. Our analysis of inter-hemispheric temperature variability in an ensemble of climate model simulations for the past millennium suggests that models tend to overemphasize Northern Hemisphere-Southern Hemisphere synchronicity by underestimating the role of internal ocean-atmosphere dynamics, particularly in the ocean-dominated Southern Hemisphere. Our results imply that climate system predictability on decadal to century timescales may be lower than expected based on assessments of external climate forcing and Northern Hemisphere temperature variations alone.

  16. Novel hemispheric image formation: concepts and applications

    NASA Astrophysics Data System (ADS)

    Thibault, Simon; Konen, Pierre; Roulet, Patrice; Villegas, Mathieu

    2008-04-01

    Panoramic and hemispheric lens technologies represent new and exciting opportunities in both imaging and projection systems. Such lenses offer intriguing applications for the transportation/automotive industry, in the protection of civilian and military areas, business. In this paper we describe a new optical design technique that provides a greater degree of freedom in producing a variety of hemispheric spatial light distribution areas. This innovative optical design strategy, of generating and controlling image mapping, has been successful in producing high-resolution imaging and projection systems. This success has subsequently generated increased interest in the high-resolution camera/projector and the concept of absolute measurement with high-resolution wide-angle lenses. The new technique described in this paper uses optimization techniques to improve the performance of a customized wide-angle lens optical system for a specific application. By adding a custom angle-to-pixel ratio at the optical design stage, this customized optical system provides ideal image coverage while reducing and optimizing signal processing. This novel image formation technique requires the development of new algorithms in order to view the panoramic image on a display without any residual distortion.

  17. 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.

  18. A Search for Hemispheric Asymmetry on Triton

    NASA Astrophysics Data System (ADS)

    McIntosh, C. M.; Storrs, A. D.

    2004-12-01

    We will present reconstructed images of Neptune's largest satellite Triton as part of an investigation of hemispheric asymmetry. The images we observed from the Hubble Space Telescope in July of 1997, using the Wide Field/Planetary Camera. The images were taken in several filters: F439W, F555W, and F791W. Image restoration was performed using the MISTRAL program (Mugnier, Fusco, and Conan 2003). We present the ratio between the filters to determine if there is any hemispheric color asymmetry at this time. The photometry of Triton appears normal in this data although Hicks and Buratti (2004) observe Triton to be anomalously red in August of 1997. References: Hicks, M.D., and Buratti, B.J. (2004): "The Spectral Variability of Triton from 1997-2000", Icarus 171 pp. 210-218 Mugnier, L.M., T. Fusco, and J.-M. Conan, 2003. "MISTRAL: a Myopic Edge-Preserving Image Restoration Method. Applicaton to Astronomical Adaptive Optics Corrected Long-Exposure Images." JOSA A (submitted)

  19. Changes in computed tomography perfusion parameters after superficial temporal artery to middle cerebral artery bypass: an analysis of 29 cases.

    PubMed

    Serrone, Joseph C; Jimenez, Lincoln; Hanseman, Dennis J; Carroll, Christopher P; Grossman, Aaron W; Wang, Lily; Vagal, Achala; Choutka, Ondrej; Andaluz, Norberto; Ringer, Andrew J; Abruzzo, Todd; Zuccarello, Mario

    2014-12-01

    Introduction Analysis of computed tomography perfusion (CTP) studies before and after superficial temporal artery to middle cerebral artery (STA-MCA) bypass is warranted to better understand cerebral steno-occlusive pathology. Methods Retrospective review was performed of STA-MCA bypass patients with steno-occlusive disease with CTP before and after surgery. CTP parameters were evaluated for change after STA-MCA bypass. Results A total of 29 hemispheres were bypassed in 23 patients. After STA-MCA bypass, mean transit time (MTT) and time to peak (TTP) improved. When analyzed as a ratio to the contralateral hemisphere, MTT, TTP, and cerebral blood flow (CBF) improved. There was no effect of gender, double vessel versus single vessel bypass, or time until postoperative CTP study to changes in CTP parameters after bypass. Conclusions Blood flow augmentation after STA-MCA bypass may best be assessed by CTP using baseline MTT or TTP and ratios of MTT, TTP, or CBF to the contralateral hemisphere. The failure of cerebrovascular reserve to improve after cerebral bypass may indicate irreversible loss of autoregulation with chronic cerebral vasodilation or the inability of CTP to detect these improvements.

  20. 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.

  1. Cerebral lateralization determines hand preferences in Australian parrots.

    PubMed

    Brown, Culum; Magat, Maria

    2011-08-23

    Individual preference for the use of one limb over the other to explore the environment or manipulate objects is common trait among vertebrates. Here, we explore the hypothesis that limb preference is determined by the engagement of a particular cerebral hemisphere to analyse certain stimuli. We recorded the eye and foot preferences of 322 individuals from 16 species of Australian parrots while investigating potential food items. Across all species, eye preferences explained 99 per cent of the variation in foot use in Australian parrots. The vast majority of species showed significant relationships between eye and foot preferences at the population level.

  2. Brain connectivity and the self: the case of cerebral disconnection.

    PubMed

    Uddin, Lucina Q

    2011-03-01

    Over the past several years, the study of self-related cognition has garnered increasing interest amongst psychologists and cognitive neuroscientists. Concomitantly, lesion and neuroimaging studies have demonstrated the importance of intact cortico-cortical and cortico-subcortical connections for supporting high-level cognitive functions. Commissurotomy or "split-brain" patients provide unique insights into the role of the cerebral commissures in maintaining an individual's sense of self, as well as into the unique self-representation capabilities of each cerebral hemisphere. Here we review empirical work examining the integrity of self-related processes in patients with various disconnection syndromes, focusing on studies of self-recognition, ownership, and agency. Taken together, this body of work suggests that an intact corpus callosum enabling interhemispheric transfer is necessary for some, but not all types of self-representations.

  3. 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.

  4. 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

  5. Alterations in regional cerebral blood flow in neonatal stroke: preliminary findings with color Doppler sonography.

    PubMed

    Taylor, G A

    1994-01-01

    Little information is available regarding alterations in regional cerebral blood flow and vascularity on cranial sonography in infants with focal ischemic brain injury. This study describes the use of color Doppler sonography in the characterization of these changes following acute neonatal stroke. Color Doppler examinations were performed as part of the series of clinically indicated cranial sonograms in eight infants with clinical, sonographic, and CT evidence of acute cerebral infarction. The cerebral vascularity of each hemisphere was assessed for symmetry and for presence of abnormal blood vessels. Initial Doppler study in four infants with hypoxic-ischemic infarcts showed increased size and number of visible vessels in the periphery of the infarct and increased mean blood flow velocity in vessels supplying or draining the infarcted areas. Diminished vessel number and size and frequency shifts suggestive of decreased hemispheric perfusion was identified in one infant with middle cerebral artery insufficiency. Repeat Doppler studies were performed on two infants. These showed the development of multiple small, irregular blood vessels in the periphery of the infarct. Focal abnormalities in regional cerebral blood flow may be present as part of the normal healing process following neonatal stroke, and can be demonstrated with color Doppler sonography. PMID:7915832

  6. 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…

  7. 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.

  8. 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…

  9. Variable left-hemisphere language and orthographic lateralization reduces right-hemisphere face lateralization.

    PubMed

    Dundas, Eva M; Plaut, David C; Behrmann, Marlene

    2015-05-01

    It is commonly believed that, in right-handed individuals, words and faces are processed by distinct neural systems: one in the left hemisphere (LH) for words and the other in the right hemisphere (RH) for faces. Emerging evidence suggests, however, that hemispheric selectivity for words and for faces may not be independent of each other. One recent account suggests that words become lateralized to the LH to interact more effectively with language regions, and subsequently, as a result of competition with words for representational space, faces become lateralized to the RH. On this interactive account, left-handed individuals, who as a group show greater variability with respect to hemispheric language dominance, might be expected to show greater variability in their degree of RH lateralization of faces as well. The current study uses behavioral measures and ERPs to compare the hemispheric specialization for both words and faces in right- and left-handed adult individuals. Although both right- and left-handed groups demonstrated LH over RH superiority in discrimination accuracy for words, only the right-handed group demonstrated RH over LH advantage in discrimination accuracy for faces. Consistent with this, increased right-handedness was related to an increase in RH superiority for face processing, as measured by the strength of the N170 ERP component. Interestingly, the degree of RH behavioral superiority for face processing and the amplitude of the RH N170 for faces could be predicted by the magnitude of the N170 ERP response to words in the LH. These results are discussed in terms of a theoretical account in which the typical RH face lateralization fails to emerge in individuals with atypical language lateralization because of weakened competition from the LH representation of words.

  10. Comparison of functional magnetic resonance imaging in cerebral activation between normal Uygur and Mandarin participants in semantic identification task

    PubMed Central

    Xi, Yan-Ling; Tian, Qing; Tuerxun, Tuerhong; Kaheman, Kuerbannaimu; Jiang, Chun-Hui; Huang, Hai-Xia; Wang, Bao-Lan

    2015-01-01

    Purpose: This study utilized blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) technology to study the activated cerebral regions in normal participants whose native language was Uyghur or Chinese. Methods: We collected the fMRI data from 15 Uyghur-speaking volunteers and 15 Mandarin-speaking volunteers when executing the semantic identification task and compared the results of two groups. Results: Statistically significant difference of brain activation was found primarily in the left anterior cingulate gyrus (BA23) and the midline precuneus (P<0.05). When performing the semantic identification task, the Uyghur group exhibited significant activation in these two regions, whereas the Chinese group demonstrated relatively weak activation in these areas. Conclusion: The cerebral regions activated by Uyghur and Chinese semantic identification are not identical, the dominant hemisphere for both languages is the left cerebral hemisphere. The left anterior cingulate gyrus might have a language function in Uyghur semantic processing. PMID:26550318

  11. Cerebral hemorrhagic lesions produced by Paragonimus mexicanus. Report of three cases in Costa Rica.

    PubMed

    Brenes Madrigal, R; Rodríguez-Ortiz, B; Vargas Solano, G; Ocamp Obando, E M; Ruiz Sotela, P J

    1982-05-01

    Three cases of cerebral lesions due to Paragonimus mexicanus in Costa Rica are reported, two of which were fatal. At autopsy a hemorrhagic, well circumscribed lesion was found in the hemispheres which microscopically consisted of a recent hemorrhage surrounded by a halo of eosinophils, with giant cell granulomas and Charcot-Leyden crystals. Eggs of P. mexicanus outside the brain were demonstrated in both fatal cases--in an eosinophilic pericarditis in one and in the other in multiple lesions of the liver and lungs. The third patient had a hemorrhagic cerebral lesion which was surgically evacuated; the patient recovered. Eggs were demonstrated in serial sections of the material resected.

  12. 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.

  13. Evaluation of regional cerebral blood flow in patient with atypical senile dementia with asymmetrical calcification.

    PubMed

    Shoyama, Masaru; Ukai, Satoshi; Shinosaki, Kazuhiro

    2015-12-01

    We report an 83-year-old woman with atypical senile dementia with Fahr-type calcification. Brain computed tomography demonstrated asymmetrical calcification predominant in the basal ganglia on the right side and pronounced diffuse cortical atrophy in the frontotemporal areas. The patient was clinically diagnosed with diffuse neurofibrillary tangles with calcification. Brain single photon emission computed tomography findings revealed that cerebral blood flow was reduced on the right side, as compared with the left side, in widespread areas. Hemispheric asymmetry in both calcification and cerebral blood flow suggests a relationship between calcification and vascular changes. PMID:25737312

  14. Cerebral phaeohyphomycosis by Exophiala dermatitidis.

    PubMed

    Sood, S; Vaid, V K; Sharma, M; Bhartiya, H

    2014-01-01

    Cerebral phaeohyphomycosis is a rare and frequently fatal disease. We report a case of cerebral phaeohyphomycosis caused by Exophiala dermatitidis in a young immuno competent male presenting to a tertiary care hospital in Jaipur. PMID:24713913

  15. 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

  16. 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.

  17. Transient aphasias after left hemisphere resective surgery

    PubMed Central

    Wilson, Stephen M.; Lam, Daniel; Babiak, Miranda; Perry, David; Shih, Tina; Hess, Christopher P.; Berger, Mitchel S.; Chang, Edward F.

    2015-01-01

    Object Transient aphasias are often observed in the first few days in patients who undergo surgical resection in the language-dominant hemisphere. The aims of this prospective study were to characterize the incidence and nature of these aphasias, and to determine whether there are relationships between location of the surgical site and deficits in specific language domains. Methods 110 patients undergoing resection to the language-dominant hemisphere participated in the study. Patients’ language was evaluated prior to surgery, 2-3 days post-surgery, and 1 month post-surgery using the Western Aphasia Battery and the Boston Naming Test. Voxel-based lesion-symptom mapping was used to identify relationships between the location of the surgical site assessed by MRI, and deficits in fluency, information content, comprehension, repetition, and naming. Results 71% of patients were classified as aphasic based on the Western Aphasia Battery 2-3 days post-surgery, with deficits observed in each of the language domains examined. Fluency deficits were associated with resection of the precentral gyrus and adjacent inferior frontal cortex. Reduced information content of spoken output was associated with resection of the ventral precentral gyrus and posterior inferior frontal gyrus (pars opercularis). Repetition deficits were associated with resection of the posterior superior temporal gyrus. Naming deficits were associated with resection of ventral temporal cortex, with mid temporal and posterior temporal damage more predictive of naming deficits than anterior temporal damage. By 1 month post-surgery, nearly all language deficits were resolved, and no language measure except for naming differed significantly from pre-surgical levels. Conclusions These findings show that transient aphasias are very common after left hemisphere resective surgery, and that the precise nature of the aphasia depends on the specific location of the surgical site. This patient cohort provides a unique

  18. Neuroprotection after cerebral ischemia

    PubMed Central

    Namura, Shobu; Ooboshi, Hiroaki; Liu, Jialing; Yenari, Midori A.

    2013-01-01

    Cerebral ischemia, a focal or global insufficiency of blood flow to the brain, can arise through multiple mechanisms, including thrombosis and arterial hemorrhage. Ischemia is a major driver of stroke, one of the leading causes of morbidity and mortality worldwide. While the general etiology of cerebral ischemia and stroke has been known for some time, the conditions have only recently been considered treatable. This report describes current research in this field seeking to fully understand the pathomechanisms underlying stroke; to characterize the brain’s intrinsic injury, survival, and repair mechanisms; to identify putative drug targets as well as cell-based therapies; and to optimize the delivery of therapeutic agents to the damaged cerebral tissue. PMID:23488559

  19. The influence of context on hemispheric recruitment during metaphor processing.

    PubMed

    Diaz, Michele T; Hogstrom, Larson J

    2011-11-01

    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 language processes and facilitate comprehension. Here we investigated how figurativeness and context influenced brain activation, with a specific interest in right hemisphere function. Previous work in our laboratory indicated that novel stimuli engaged right inferior frontal gyrus (IFG) and that both novel and familiar metaphors engaged right IFG and right temporal pole. The graded salience hypothesis proposes that context may lessen integration demands, increase the salience of metaphors, and thereby reduce right hemisphere recruitment for metaphors. In the present study, fMRI was used to investigate brain function, whereas participants read literal and metaphoric sentences that were preceded by either a congruent or an incongruent literal sentence. Consistent with prior research, all sentences engaged traditional left hemisphere regions. Differences between metaphors and literal sentences were observed, but only in the left hemisphere. In contrast, a main effect of congruence was found in the right IFG, the right temporal pole, and the dorsal medial pFC. Partially consistent with the graded salience hypothesis, our results highlight the strong influence of context on language, demonstrate the importance of the right hemisphere in discourse, and suggest that, in a wider discourse context, congruence has a greater influence on right hemisphere recruitment than figurativeness.

  20. Memory impairment caused by cerebral hematoma in the left medial temporal lobe due to ruptured posterior cerebral artery aneurysm

    PubMed Central

    2014-01-01

    Background Cognitive disorders, such as memory disturbances, are often observed following a subarachnoid hemorrhage. We present a very rare case where rupture of a posterior cerebral artery aneurysm caused restricted damage to the hippocampus unilaterally, and caused memory disturbances. Case presentation A 56-year-old, right-handed man, with a formal education history of 16 years and company employees was admitted to our hospital because of a consciousness disturbance. He was diagnosed as having a subarachnoid hemorrhage due to a left posterior cerebral artery dissecting aneurysm, and coil embolization was performed. Subsequently, he had neither motor paresis nor sensory disturbances, but he showed disorientation, and both retrograde and anterograde amnesia. Although immediate recall and remote memory were almost intact, his recent memory was moderately impaired. Both verbal and non-verbal memories were impaired. Brain computed tomography (CT) and magnetic resonance imaging (MRI) revealed a cerebral hematoma in the left temporal lobe involving the hippocampus and parahippocampal gyrus, and single-photon emission computed tomography (SPECT) demonstrated low perfusion areas in the left medial temporal lobe. Conclusions We suggest that the memory impairment was caused by local tissue destruction of Papez’s circuit in the dominant hemisphere due to the cerebral hematoma. PMID:24602130

  1. 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

  2. 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).

  3. Dynamics of charged hemispherical soap bubbles

    NASA Astrophysics Data System (ADS)

    Hilton, J. E.; van der Net, A.

    2009-04-01

    Raising the potential of a charged hemispherical soap bubble over a critical limit causes deformation of the bubble into a cone and ejection of a charged liquid jet. This is followed by a mode which has not previously been observed in bubbles, in which a long cylindrical liquid film column is created and collapses due to a Rayleigh-Plateau instability creating child bubbles. We show that the formation of the column and subsequent creation of child bubbles is due to a drop in potential caused by the ejection of charge from the system via the jet. Similar dynamics may occur in microscopic charged liquid droplets (electrospray processes), causing the creation of daughter droplets and long liquid spindles.

  4. 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.

  5. Antarctic role in Northern Hemisphere glaciation

    NASA Astrophysics Data System (ADS)

    Woodard, Stella C.; Rosenthal, Yair; Miller, Kenneth G.; Wright, James D.; Chiu, Beverly K.; Lawrence, Kira T.

    2014-11-01

    Earth’s climate underwent a major transition from the warmth of the late Pliocene, when global surface temperatures were ~2° to 3°C higher than today, to extensive Northern Hemisphere glaciation (NHG) ~2.73 million years ago (Ma). We show that North Pacific deep waters were substantially colder (4°C) and probably fresher than the North Atlantic Deep Water before the intensification of NHG. At ~2.73 Ma, the Atlantic-Pacific temperature gradient was reduced to <1°C, suggesting the initiation of stronger heat transfer from the North Atlantic to the deep Pacific. We posit that increased glaciation of Antarctica, deduced from the 21 ± 10-meter sea-level fall from 3.15 to 2.75 Ma, and the development of a strong polar halocline fundamentally altered deep ocean circulation, which enhanced interhemispheric heat and salt transport, thereby contributing to NHG.

  6. Paleoceanography. Antarctic role in Northern Hemisphere glaciation.

    PubMed

    Woodard, Stella C; Rosenthal, Yair; Miller, Kenneth G; Wright, James D; Chiu, Beverly K; Lawrence, Kira T

    2014-11-14

    Earth's climate underwent a major transition from the warmth of the late Pliocene, when global surface temperatures were ~2° to 3°C higher than today, to extensive Northern Hemisphere glaciation (NHG) ~2.73 million years ago (Ma). We show that North Pacific deep waters were substantially colder (4°C) and probably fresher than the North Atlantic Deep Water before the intensification of NHG. At ~2.73 Ma, the Atlantic-Pacific temperature gradient was reduced to <1°C, suggesting the initiation of stronger heat transfer from the North Atlantic to the deep Pacific. We posit that increased glaciation of Antarctica, deduced from the 21 ± 10-meter sea-level fall from 3.15 to 2.75 Ma, and the development of a strong polar halocline fundamentally altered deep ocean circulation, which enhanced interhemispheric heat and salt transport, thereby contributing to NHG. PMID:25342658

  7. Regulation of cerebral blood flow during exercise.

    PubMed

    Querido, Jordan S; Sheel, A William

    2007-01-01

    Constant cerebral blood flow (CBF) is vital to human survival. Originally thought to receive steady blood flow, the brain has shown to experience increases in blood flow during exercise. Although increases have not consistently been documented, the overwhelming evidence supporting an increase may be a result of an increase in brain metabolism. While an increase in metabolism may be the underlying causative factor for the increase in CBF during exercise, there are many modulating variables. Arterial blood gas tensions, most specifically the partial pressure of carbon dioxide, strongly regulate CBF by affecting cerebral vessel diameter through changes in pH, while carbon dioxide reactivity increases from rest to exercise. Muscle mechanoreceptors may contribute to the initial increase in CBF at the onset of exercise, after which exercise-induced hyperventilation tends to decrease flow by pial vessel vasoconstriction. Although elite athletes may benefit from hyperoxia during intense exercise, cerebral tissue is well protected during exercise, and cerebral oxygenation does not appear to pose a limiting factor to exercise performance. The role of arterial blood pressure is important to the increase in CBF during exercise; however, during times of acute hypotension such as during diastole at high-intensity exercise or post-exercise hypotension, cerebral autoregulation may be impaired. The impairment of an increase in cardiac output during exercise with a large muscle mass similarly impairs the increase in CBF velocity, suggesting that cardiac output may play a key role in the CBF response to exercise. Glucose uptake and CBF do not appear to be related; however, there is growing evidence to suggest that lactate is used as a substrate when glucose levels are low. Traditionally thought to have no influence, neural innervation appears to be a protective mechanism to large increases in cardiac output. Changes in middle cerebral arterial velocity are independent of changes in

  8. Geologic map of the northern hemisphere of Vesta based on Dawn Framing Camera (FC) images

    NASA Astrophysics Data System (ADS)

    Ruesch, Ottaviano; Hiesinger, Harald; Blewett, David T.; Williams, David A.; Buczkowski, Debra; Scully, Jennifer; Yingst, R. Aileen; Roatsch, Thomas; Preusker, Frank; Jaumann, Ralf; Russell, Christopher T.; Raymond, Carol A.

    2014-12-01

    The Dawn Framing Camera (FC) has imaged the northern hemisphere of the Asteroid (4) Vesta at high spatial resolution and coverage. This study represents the first investigation of the overall geology of the northern hemisphere (22-90°N, quadrangles Av-1, 2, 3, 4 and 5) using these unique Dawn mission observations. We have compiled a morphologic map and performed crater size-frequency distribution (CSFD) measurements to date the geologic units. The hemisphere is characterized by a heavily cratered surface with a few highly subdued basins up to ∼200 km in diameter. The most widespread unit is a plateau (cratered highland unit), similar to, although of lower elevation than the equatorial Vestalia Terra plateau. Large-scale troughs and ridges have regionally affected the surface. Between ∼180°E and ∼270°E, these tectonic features are well developed and related to the south pole Veneneia impact (Saturnalia Fossae trough unit), elsewhere on the hemisphere they are rare and subdued (Saturnalia Fossae cratered unit). In these pre-Rheasilvia units we observed an unexpectedly high frequency of impact craters up to ∼10 km in diameter, whose formation could in part be related to the Rheasilvia basin-forming event. The Rheasilvia impact has potentially affected the northern hemisphere also with S-N small-scale lineations, but without covering it with an ejecta blanket. Post-Rheasilvia impact craters are small (<60 km in diameter) and show a wide range of degradation states due to impact gardening and mass wasting processes. Where fresh, they display an ejecta blanket, bright rays and slope movements on walls. In places, crater rims have dark material ejecta and some crater floors are covered by ponded material interpreted as impact melt.

  9. 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.

  10. Unusual Cerebral Emboli.

    PubMed

    Zakhari, Nader; Castillo, Mauricio; Torres, Carlos

    2016-02-01

    The heart and the carotid arteries are the most common sites of origin of embolic disease to the brain. Clots arising from these locations are the most common types of brain emboli. Less common cerebral emboli include air, fat, calcium, infected vegetations, and tumor cells as well as emboli originating in the venous system. Although infarcts can be the final result of any type of embolism, described herein are the ancillary and sometimes unique imaging features of less common types of cerebral emboli that may allow for a specific diagnosis to be made or at least suspected in many patients.

  11. The effect of doxazosin mesilate on cerebral blood flow in patients with hypertension and chronic cerebral infarction.

    PubMed

    Usuda, Kazuhiro; Katayama, Yasuo

    2009-06-01

    alpha(1)-Adrenoceptor antagonists are useful antihypertensive agents for patients with hypertension who have hyperlipidemia, benign prostatic hyperplasia, or pheochromocytoma. The purpose of this study was to evaluate the effect of the alpha(1)-adrenoceptor antagonist, doxazosin mesilate, on cerebral blood flow (CBF) and flow velocity in the common carotid artery in patients with hypertension and chronic cerebral infarction. Doxazosin mesilate (1 mg/day) was orally administered for 4 to 8 weeks to 7 patients with hypertension 4 weeks after the onset of cerebral infarction. We determined blood pressure, heart rate, CBF measured with autoradiography single photon emission computed tomography (SPECT) with N-isopropyl-p-[(123)I] iodoamphetamine ((123)I-IMP) as a tracer, and the maximum, minimum and mean flow velocities in the common carotid arteries measured with duplex carotid ultrasonography before and 4 to 8 weeks after the beginning of treatment. Mean CBF was defined as the mean count of tracer from the 8 regions of interest (ROIs) in the frontal, parietal, occipital, and temporal cortices of the cerebral hemisphere. Values were analyzed with paired t tests. With administration of doxazosin mesilate, systolic pressure significantly decreased from 152 +/- 11 to 137 +/- 7 mmHg (p<0.01), but diastolic pressure and heart rate were unchanged. Mean CBF was improved significantly from 32.0 +/- 4.1 to 34.7 +/- 4.1 mL/100 g brain/min (p<0.01) in the ipsilateral cerebral cortex and from 32.6 +/- 6.2 to 36.2 +/- 5.1 mL/100 g brain/min (p<0.05) in the contralateral cerebral cortex. The maximum, minimum, and mean flow velocities in the bilateral common carotid arteries were not changed significantly. In the present study, the improvement of mean CBF in the ipsilateral and contralateral cerebral cortices was demonstrated in patients with hypertension and chronic cerebral infarction after the treatment with doxazosin mesilate. Doxazosin mesilate might be an effective

  12. Re-evaluating split-fovea processing in word recognition: effects of retinal eccentricity on hemispheric dominance.

    PubMed

    Jordan, Timothy R; Paterson, Kevin B; Stachurski, Marcin

    2008-11-01

    Several studies have claimed that hemispheric asymmetries affect word recognition right up to the point of fixation because each fovea is split precisely at its vertical midline and information presented either side of this midline projects unilaterally to different, contralateral hemispheres. To investigate this claim, four-letter words were presented to the left or right of fixation, either close to fixation entirely in foveal vision (0.15, 0.25, and 0.35 degrees from fixation) or further from fixation entirely in extrafoveal vision (2.00, 2.10, and 2.20 degrees from fixation). Fixation location and stimulus presentation were controlled using an eye-tracker linked to a fixation-contingent display and performance was assessed using a forced-choice task to suppress confounding effects of guesswork. A left hemisphere advantage was observed for words presented in extrafoveal locations but no hemisphere advantage (left or right) was observed for words presented in any foveal location. These findings support the well-established view that words encountered outside foveal vision project to different, contralateral hemispheres but indicate that this division for word recognition occurs only outside the fovea and provide no support for the claim that a functional split in hemispheric processing exists at the point of fixation. PMID:18999347

  13. 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.

  14. [Cerebral hemorrhage associated with the use phenylpropanolamine].

    PubMed

    Barinagarrementería, F; Méndez, A; Vega, F

    1990-10-01

    Phenylpropanolamine is a sympatheticomimetic agent which is widely used in pharmacologic preparations to treat nasal congestion, and to produce and anorexigenic or stimulant action. In the last years complications affecting the nervous system or the general condition have been reported. There is still controversy with regard to the safety of this pharmacologic agent. In this study we report two cases of parenchymal cerebral hemorrhage secondary to phenylpropanolamine administration. In the second case we observed angiographic findings of a reversible vasculopathy.

  15. Maurice Ravel and right-hemisphere musical creativity: influence of disease on his last musical works?

    PubMed

    Amaducci, L; Grassi, E; Boller, F

    2002-01-01

    The problem of finding correspondence between a particular neuronal organization and a specific function of the human brain remains a central question of neuroscience. It is sometimes thought that language and music are two sides of the same intellectual coin, but research on brain-damaged patients has shown that the loss of verbal functions (aphasia) is not necessarily accompanied by a loss of musical abilities (amusia). Amusia without aphasia has also been described. This double dissociation indicates functional autonomy in these mental processes. Yet verbal and musical impairments often occur together. The global picture that emerges from studies of music and its neural substrate is by no means clear and much depends on which subjects and which aspect of musical abilities are investigated. An illustration of these concepts is provided by the case of the French composer Maurice Ravel, who suffered from a progressive cerebral disease of uncertain aetiology, with prominent involvement of the left hemisphere. As a result, Ravel experienced aphasia and apraxia and became unable to compose. The available facts favour a clinical diagnosis of primary progressive aphasia (PPA), with the possibility of an overlap with corticobasal degeneration (CBD). In view of Ravel's clinical history, we propose that two of his final compositions, the Bolero and the Concerto for the Left Hand, include certain patterns characteristic of right-hemisphere musical abilities and may show the influence of disease on the creative process.

  16. 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

  17. Computational Pipeline for NIRS-EEG Joint Imaging of tDCS-Evoked Cerebral Responses-An Application in Ischemic Stroke.

    PubMed

    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

  18. Influence of interhemispheric thermal gradient on the tropical climate state and Southern Hemisphere Westerlies

    NASA Astrophysics Data System (ADS)

    Lee, S.; Chiang, J. C.

    2013-12-01

    A recent paleoclimate proxy study (Anderson et al., 2009) indicated enhanced upwelling rates in the Southern Ocean during the late Pleistocene glacial termination that coincided with the deglacial warming in Antarctica and the rise in atmospheric CO2. Anderson et al. (2009) suggested the possibility of robust atmospheric teleconnections from the Northern Hemisphere to the Southern Hemisphere, specifically affecting the midlatitude westerlies. Our previous modeling study (Lee et al. 2011) showed the viability of such a teleconneciton, albeit in a relatively simplified modeling framework (an atmospheric general circulation model coupled to a simplified ocean) and using idealized experiments. In the study, we explore the climate connection between interhemispheric thermal gradient, tropical climate state, Southern Ocean wind response, and ocean overturning circulation in a realistic 21,000 year transient coupled ocean-atmosphere climate model simulation encompassing the most recent deglaciation and the Holocene (the TraCE-21k simulation). We find a significant connection between the interhemispheric surface temperature gradient and the upper level westerlies over the Southern Ocean, in particular in the South Pacific during austral winter. In tropics, we observe a marked southward shift of the tropical precipitation, indicating an alteration of the Hadley circulation. The climate response resembles our previous idealized study (Lee et al., 2011), albeit with smaller magnitude. Our results provide further evidence for the hypothesis that northern hemisphere climate changes can influence the southern hemisphere westerlies via the tropics through an atmospheric teleconnection.

  19. Tumors of the cerebral aqueduct.

    PubMed

    Ho, K L

    1982-01-01

    Two cases of tumor of the cerebral aqueduct are described. Case 1 is a pilocytic astrocytoma in a 16-year-old girl with a two-year history of intermittent increase of intracranial pressure. The tumor was completely confined within the lumen of the aqueduct. Case 2 is a subependymoma of a 68-year-old man. The tumor extended beyond the aqueduct to the periaqueductal gray matter and produced signs and symptoms suggesting normal pressure hydrocephalus. The literature contains 18 other cases of tumor of the aqueduct: 13 gliomas and five vascular malformations. All, except one, produced clinical manifestations of generalized hydrocephalus lasting from 20 days to six years. The result generally did not correspond to the histologic type of the tumor. Like gliomas of the brainstem in general, those in the aqueduct tend to occur in childhood and adolescence and affect male more than female patients.

  20. Systematization and distribution of the middle cerebral artery on the brain surface in pampas fox (Pseudalopex gymnocercus).

    PubMed

    Depedrini, J S; Campos, R

    2007-12-01

    The present study has analysed 30 pampas fox brains (Pseudalopex gymnocercus), injected with latex, aiming to systematize and describe the distribution and vascularization territories of the middle cerebral artery. After being originated from the rostral branch of the internal carotid artery this vessel formed the following collateral branches: rostral choroidal artery, rostral and caudal central branches and cortical branches. Before crossing the lateral rhinal sulcus, the common trunk of the middle cerebral artery frequently bifurcated in a rostral and a caudal branch. In a smaller amount, the common trunk did not show any bifurcation, ramifying in arborescence. The vascular territory of the pampas fox middle cerebral artery included the lateral cerebral fossa, the lateral third of the olfactory trigone, the two rostral thirds of the piriform lobe, the lateral olfactory tract and most of the convex surface of the cerebral hemisphere, except for the more rostromedial areas of the frontal lobe bordering the endomarginal sulcus in the parietal and occipital lobes as well as the transverse fissure at the caudal pole of the cerebral hemisphere.

  1. A new approach to reduce the number of animals used in experimental focal cerebral ischemia models.

    PubMed

    Burggraf, Dorothe; Martens, Helge K; Liebetrau, Martin; Vosko, Milan R; Dichgans, Martin; Hamann, Gerhard F

    2005-09-30

    We describe a novel experimental set-up that allows biochemical, immunohistochemical and morphometric recording of multiple parameters from a single rat brain. The whole brain was cut (coronal sectioning) in a volumetric manner, and 100 cryo-sections (10 microm) were collected from the region of infarction. By use of a scalpel to dissect the cryosection, crude brain material was obtained from the cortical and basal ganglia areas of ischemic and non-ischemic hemispheres. Material from four 10 microm thick sections of the same animal was pooled. About 30 microg protein lysate was extracted per four sections with various lysis buffers; this sufficed for one biochemical or enzymatic test called "micro-Western-blots" or "micro-zymographies". Scraping brain material from cryosections allows the detection of up to 25 parameters from adjacent brain sections of one single rat brain. Different analysis are possible, we have chosen, e.g. to compare factors affecting the basal lamina of cerebral microvessels like the content of the metalloproteinases-2/-9, their tissue inhibitors, the plasminogen activators, collagen type IV, parameters to test the blood-brain barrier: hemoglobin and the protein of the perfusion solution BSA and the infarction volume. On the basis of these parameters it was possible to compare the interactions of the complex processes in the ischemic brain in the same animal in adjacent sections. Thus, this method increases the validity of data comparisons and reduces significantly the number of animals needed in various experimental settings.

  2. Functional Real-Time Optoacoustic Imaging of Middle Cerebral Artery Occlusion in Mice

    PubMed Central

    Krieg, Sandro M.; Lehmberg, Jens; Lindauer, Ute; Razansky, Daniel

    2014-01-01

    Background and Purpose Longitudinal functional imaging studies of stroke are key in identifying the disease progression and possible therapeutic interventions. Here we investigate the applicability of real-time functional optoacoustic imaging for monitoring of stroke progression in the whole brain of living animals. Materials and Methods The middle cerebral artery occlusion (MCAO) was used to model stroke in mice, which were imaged preoperatively and the occlusion was kept in place for 60 minutes, after which optoacoustic scans were taken at several time points. Results Post ischemia an asymmetry of deoxygenated hemoglobin in the brain was observed as a region of hypoxia in the hemisphere affected by the ischemic event. Furthermore, we were able to visualize the penumbra in-vivo as a localized hemodynamically-compromised area adjacent to the region of stroke-induced perfusion deficit. Conclusion The intrinsic sensitivity of the new imaging approach to functional blood parameters, in combination with real time operation and high spatial resolution in deep living tissues, may see it become a valuable and unique tool in the development and monitoring of treatments aimed at suspending the spread of an infarct area. PMID:24776997

  3. Measurement of regional cerebral blood volume using the EMI 1010 scanner.

    PubMed

    Ladurner, G; Zilkha, E; Sager, W D; Iliff, L D; Lechner, H; Du Boulay, G H

    1979-05-01

    Regional cerebral blood volume (rCBV) was measured in 14 patients with normal CT scans. An EMI CT 1010 scanner was used in combination with a computer subtraction technique. The mean CBV in the cortex was 5.0 ml/100 ml of tissue and 2.2 in the white matter. Regional differences were not significant and no difference was found between the right and left hemispheres.

  4. [Cerebral blood flow disturbances after anterior choroidal artery infarcts. Anatomical and functional correlates].

    PubMed

    Rousseaux, M; Froger, J; Kozlowski, O; Steinling, M

    2001-02-01

    We have investigated the cortical and subcortical regional cerebral blood flow (rCBF) disorders resulting from infarcts of the anterior choroidal artery (AChA), and correlations with the severity of lesions, the physical and cognitive deficits, and the functional impairment. Eighteen patients presenting with recent anterior choroidal artery infarct without any other brain injury were examined at the secondary phase post-stroke using the single photon emission computed tomography technique and 133 Xenon inhalation. The rCBF and asymmetry indexes (AI) were calculated for 12 symmetrical hemispheric areas, and the cerebellum. The AI values were compared with those of 24 control subjects. The severity of the lesions was evaluated from CT scans or MRI. The neurological status (Orgogozo scale, walking disorders, MMSE, attention impairment, aphasia) and disability (functional independance measure: FIM) were assessed for each patient at the same time period. The relationships between rCBF disorders and brain lesions, and between the results of clinical investigations and rCBF disorders and brain lesions were assessed by linear regression analyses (stepwise variable selections, p=0.05). The AI values were significantly increased in the cerebral hemispheres, and this was most severe in the internal capsule (direct effect of the lesion) and the dorsolateral hemispheric cortex (diaschisis). Individual evaluations showed that AI were significantly increased in 13 patients in at least one ROI of the cerebral hemispheres, and in 3 patients in the internal capsule. Stepwise variable selections revealed that AI were best explained by the severity of the lesions in the internal capsule and the internal temporal area. The AI of the external temporal area and the internal capsule also helped explain the clinical (physical and cognitive) deficits. Thus, AChA infarcts may have relatively large effects on the central part of the lateral and dorsal cortex of the ipsilateral hemisphere

  5. 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…

  6. 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

  7. 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…

  8. 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…

  9. Assessment of Hemispheric Dominance for Language at Three Ages.

    ERIC Educational Resources Information Center

    Tegano, Deborah Walker

    The purposes of this study were to assess the development of hemispheric dominance for language function among children of 4, 7, and 10 years of age and to determine whether age predicts hemispheric dominance. Within 2 weeks of the beginning of data collection, middle-class subjects selected from private nursery schools and elementary schools…

  10. Hemispheric Asymmetry in a Face Discrimination Task in Infants.

    ERIC Educational Resources Information Center

    de Schonen, Scania; Mathivet, Eric

    1990-01-01

    Confirms the existence of a right-hemisphere advantage in the process of discriminating between face stimuli. The advantage was weaker in females than in males. No hemispheric transfer of learning was observed. Subjects were 18 infants of 42 weeks who were presented with an operant conditioning situation in which they discriminated between their…

  11. 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…

  12. 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…

  13. The Joint Development of Hemispheric Lateralization for Words and Faces

    ERIC Educational Resources Information Center

    Dundas, Eva M.; Plaut, David C.; Behrmann, Marlene

    2013-01-01

    Consistent with long-standing findings from behavioral studies, neuroimaging investigations have identified a region of the inferior temporal cortex that, in adults, shows greater face selectivity in the right than left hemisphere and, conversely, a region that shows greater word selectivity in the left than right hemisphere. What has not been…

  14. A Hemispheric Asymmetry for the Unconscious Perception of Emotion

    ERIC Educational Resources Information Center

    Smith, Stephen D.; Bulman-Fleming, M. Barbara

    2004-01-01

    Previous research has demonstrated that hemispheric asymmetries for conscious visual perception do not lead to asymmetries for unconscious visual perception. These studies utilized emotionally neutral items as stimuli. The current research utilized both emotionally negative and neutral stimuli to assess hemispheric differences for conscious and…

  15. The SPECT imaging shows the accumulation of neural progenitor cells into internal organs after systemic administration in middle cerebral artery occlusion rats.

    PubMed

    Lappalainen, Riikka S; Narkilahti, Susanna; Huhtala, Tuulia; Liimatainen, Timo; Suuronen, Tiina; Närvänen, Ale; Suuronen, Riitta; Hovatta, Outi; Jolkkonen, Jukka

    2008-08-01

    The regenerative potential of stem cells from various sources has been under intense investigation in the experimental models of cerebral ischemia. To end up with a restorative therapeutic treatment, it is crucial to get the cell transplants to the site of injury. Here, we evaluated the feasibility of small animal SPECT/CT in assessing the definite accumulation of (111)In-oxine-labeled human embryonic stem (ES) cell-derived neural progenitors and rat hippocampal progenitors after intravenous or intra-arterial administration (femoral vein vs. common carotid artery) in middle cerebral artery occlusion (MCAO) and sham-operated rats. Cell detection was carried out immediately and 24h after the infusion using a SPECT/CT device. The results showed that after intravenous injections both cell types accumulated primarily into internal organs, instead of brain. In contrast, after intra-arterial injection, a weak signal was detected in the ischemic hemisphere. Additional studies showed that the detection sensitivity of SPECT/CT device was approximately 1000 (111)In-oxine-labeled cells and labeling did not affect the cell viability. In conclusion, a small animal SPECT is powerful technique to study the whole body biodistribution of cell-based therapies. Our data showed that intravenous administration is not an optimal route to deliver neural progenitor cell-containing transplants into the brain after MCAO in rats. PMID:18572314

  16. Lateralization of the respiratory control following unilateral cerebral ischemia-reperfusion injury.

    PubMed

    Shoja, Mohammadali M; Tubbs, R Shane; Jamshidi, Masoud; Shokouhi, Ghaffar; Ansarin, Khalil

    2008-02-01

    Cerebral control of respiration has been extensively studied but at present, no evidence of cerebral laterality or dominance for respiration exists. We examined the ventilatory changes following temporary (20 min) occlusion of the right or left common carotid artery in rabbits. The corresponding groups of sham-operated rabbits were used as controls. The partial pressure of end-tidal carbon dioxide (PET(co2) ) was measured with a microstream capnograph before the operation as well as at 6h, and days 1, 4, 9 and 15 postoperation and was used to indicate the ventilatory status. The results showed that following temporary occlusion of the left common carotid artery, subjects began hypoventilation and had a progressive rise in PET(co2) on day 9 postoperation compared to the sham-operated group. However, animals that underwent occlusion of the right common carotid artery hyperventilated from as early as 6h postoperation to days 1 and 4, an effect that ceased up to day 9 postoperation. It was concluded that respiration might be under differential regulation by the two cerebral hemispheres. While the left hemispheric ischemia-reperfusion injury induced hypoventilation that of the right hemisphere resulted in hyperventilation. PMID:17981519

  17. Changes in Cerebral Cortex of Children Treated for Medulloblastoma

    SciTech Connect

    Liu, Arthur K. . E-mail: aliu1@partners.org; Marcus, Karen J.; Fischl, Bruce; Grant, P. Ellen; Young Poussaint, Tina; Rivkin, Michael J.; Davis, Peter; Tarbell, Nancy J.; Yock, Torunn I.

    2007-07-15

    Purpose: Children with medulloblastoma undergo surgery, radiotherapy, and chemotherapy. After treatment, these children have numerous structural abnormalities. Using high-resolution magnetic resonance imaging, we measured the thickness of the cerebral cortex in a group of medulloblastoma patients and a group of normally developing children. Methods and Materials: We obtained magnetic resonance imaging scans and measured the cortical thickness in 9 children after treatment of medulloblastoma. The measurements from these children were compared with the measurements from age- and gender-matched normally developing children previously scanned. For additional comparison, the pattern of thickness change was compared with the cortical thickness maps from a larger group of 65 normally developing children. Results: In the left hemisphere, relatively thinner cortex was found in the perirolandic region and the parieto-occipital lobe. In the right hemisphere, relatively thinner cortex was found in the parietal lobe, posterior superior temporal gyrus, and lateral temporal lobe. These regions of cortical thinning overlapped with the regions of cortex that undergo normal age-related thinning. Conclusion: The spatial distribution of cortical thinning suggested that the areas of cortex that are undergoing development are more sensitive to the effects of treatment of medulloblastoma. Such quantitative methods may improve our understanding of the biologic effects that treatment has on the cerebral development and their neuropsychological implications.

  18. Regional cerebral blood flow in schizophrenics. Tests using the xenon Xe 133 inhalation method

    SciTech Connect

    Ariel, R.N.; Golden, C.J.; Berg, R.A.; Quaife, M.A.; Dirksen, J.W.; Forsell, T.; Wilson, J.; Graber, B.

    1983-03-01

    Measurements of intrahemispheric and bilateral regional cerebral blood flow (CBF) for gray and white matter were compared in 29 schizophrenic patients and 22 normal controls, using the xenon Xe 133 inhalation method. Results showed significantly lower CBF values for all brain regions in the schizophrenic group, and post hoc comparisons showed relatively greater reduced gray-matter CBF values in the anterior areas of the brain. There was also a left-hemisphere frontal loss similar to that reported previously, although it was in the context of a generalized loss in anterior functioning. Interhemispheric comparison within both groups showed no differences between homologous regions for gray matter, and greater white-matter CBF values in the right hemisphere than in the left hemisphere. The findings support a hypothesis of a bilateral anterior deficit in schizophrenia.

  19. Role of Histamine and Its Receptors in Cerebral Ischemia

    PubMed Central

    2012-01-01

    Histamine is recognized as a neurotransmitter or neuromodulator in the brain, and it plays a major role in the pathogenic progression after cerebral ischemia. Extracellular histamine increases gradually after ischemia, and this may come from histaminergic neurons or mast cells. Histamine alleviates neuronal damage and infarct volume, and it promotes recovery of neurological function after ischemia; the H1, H2, and H3 receptors are all involved. Further studies suggest that histamine alleviates excitotoxicity, suppresses the release of glutamate and dopamine, and inhibits inflammation and glial scar formation. Histamine may also affect cerebral blood flow by targeting to vascular smooth muscle cells, and promote neurogenesis. Moreover, endogenous histamine is an essential mediator in the cerebral ischemic tolerance. Due to its multiple actions, affecting neurons, glia, vascular cells, and inflammatory cells, histamine is likely to be an important target in cerebral ischemia. But due to its low penetration of the blood-brain barrier and its wide actions in the periphery, histamine-related agents, like H3 antagonists and carnosine, show potential for cerebral ischemia therapy. However, important questions about the molecular aspects and pathophysiology of histamine and related agents in cerebral ischemia remain to be answered to form a solid scientific basis for therapeutic application. PMID:22860191

  20. Evaluation of postural stability in children with hemiplegic cerebral palsy

    PubMed Central

    Kenis-Coskun, Ozge; Giray, Esra; Eren, Beyhan; Ozkok, Ozlem; Karadag-Saygi, Evrim

    2016-01-01

    [Purpose] Postural stability is the ability of to maintain the position of the body within the support area. This function is affected in cerebral palsy. The aim of the present study was to compare static and dynamic postural stability between children with hemiplegic cerebral palsy and healthy controls. [Subjects and Methods] Thirty-seven children between the ages of 5 and 14 diagnosed with hemiplegic cerebral palsy (19 right, 18 left) and 23 healthy gender- and age-matched controls were included in the study. Postural stability was evaluated in both of the groups using a Neurocom Balance. Sway velocity was measured both with the eyes open and closed. Sit to stand and turning abilities were also assessed. [Results] The sway velocities with the eyes open and closed were significantly different between the groups. The weight transfer time in the Sit to Stand test was also significantly slower in children with cerebral palsy. Children with cerebral palsy also showed slower turning times and greater sway velocities during the Step and Quick Turn test on a force plate compared with their healthy counterparts. [Conclusion] Both static and dynamic postural stability parameters are affected in hemiplegic cerebral palsy. Further research is needed to define rehabilitation interventions to improve these parameters in patients. PMID:27313338