Functional Plasticity after Unilateral Vestibular Midbrain Infarction in Human Positron Emission Tomography

The aim of the study was to uncover mechanisms of central compensation of vestibular function at brainstem, cerebellar, and cortical levels in patients with acute unilateral midbrain infarctions presenting with an acute vestibular tone imbalance. Eight out of 17 patients with unilateral midbrain infarctions were selected on the basis of signs of a vestibular tone imbalance, e.g., graviceptive (tilts of perceived verticality) and oculomotor dysfunction (skew deviation, ocular torsion) in F18-fluordeoxyglucose (FDG)-PET at two time points: A) in the acute stage, and B) after recovery 6 months later. Lesion-behavior mapping analyses with MRI verified the exact structural lesion sites. Group subtraction analyses and comparisons with healthy controls were performed with Statistic Parametric Mapping for the PET data. A comparison of PET A of acute-stage patients with that of healthy controls showed increases in glucose metabolism in the cerebellum, motion-sensitive visual cortex areas, and inferior temporal lobe, but none in vestibular cortex areas. At the supratentorial level bilateral signal decreases dominated in the thalamus, frontal eye fields, and anterior cingulum. These decreases persisted after clinical recovery in contrast to the increases. The transient activations can be attributed to ocular motor and postural recovery (cerebellum) and sensory substitution of vestibular function for motion perception (visual cortex). The persisting deactivation in the thalamic nuclei and frontal eye fields allows alternative functional interpretations of the thalamic nuclei: either a disconnection of ascending sensory input occurs or there is a functional mismatch between expected and actual vestibular activity. Our data support the view that both thalami operate separately for each hemisphere but receive vestibular input from ipsilateral and contralateral midbrain integration centers. Normally they have gatekeeper functions for multisensory input to the cortex and automatic motor output to subserve balance and locomotion, as well as sensorimotor integration

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Mapping Morality with a Compass: Testing the theory of ‘morality as cooperation’ with a new questionnaire

Morality-as-Cooperation (MAC) is the theory that morality is a collection of biological and cultural solutions to the problems of cooperation recurrent in human social life. MAC uses game theory to identify distinct types of cooperation, and predicts that each will be considered morally relevant, and each will give rise to a distinct moral domain. Here we test MAC's predictions by developing a new self-report measure of morality, the Morality-as-Cooperation Questionnaire (MAC-Q), and comparing its psychometric properties to those of the Moral Foundations Questionnaire (MFQ). Over four studies, the results support MAC's seven-factor model of morality, but not the MFQ's five-factor model. Thus MAC emerges as the best available compass with which to explore the moral landscape

Inzidenz, Diagnose und Anatomie der Anosognosie für Hemiparese

The present study investigated the incidence and diagnosis as well as the analysis of lesion location of stroke patients with anosognosia for hemiparesis or hemiplegia. These patients typically are convinced that their limbs function normally although they have obvious motor defects. Such patients may experience the paretic limbs as strange or as not belonging to them, or even attribute ownership to another person and try to push their paralyzed limb out of bed. In previous studies, the incidence of anosognosia for hemiparesis varied between 17% and 58% in samples of brain damaged patients with hemiparesis. One explanation for this wide variation might be different criteria used for the diagnosis of anosognosia. The sample of the present study consisted of 128 acute stroke patients with hemiparesis or hemiplegia. The patients were tested for anosognosia for hemiparesis using the anosognosia scale of Bisiach et al. (1986). Analysis revealed that 94% of those patients rated having 'mild anosognosia', i.e. who did not acknowledge their hemiparesis spontaneously following a general question about their complaints, suffered from and mentioned other neurological deficits, such as dysarthria, ptosis, or headache. However, they immediately acknowledged their paresis when they were asked about the strength of their limbs. Obviously other deficits had a higher impact for these subjects. In fact, they had significantly milder paresis compared to patients who denied their disorder even when asked about their limbs. The data suggest that patients who do not mention their paresis spontaneously, but directly when addressed by the examiner should not be diagnosed having 'anosognosia'. If this more conservative cut-off criterion is applied to the data of the present as well as of previous studies, a frequency between 10% and 18% for anosognosia for hemiparesis is obtained in unselected samples of acute, hemiparetic stroke patients. The incidence of anosognosia for hemiparesis thus seems to be less frequent than previously assumed. Previous studies have favored the idea that anosognosia for hemiparesis is related to disturbed right hemisphere processes. Here we present data supporting the hypothesis that the key area typically associated with anosognosia for hemiparesis/-plegia is the right posterior insula. Neuronal responses in monkeys suggested that this region represents a somatosensory as well as a motor association area. Obviously signal processing in the insular cortex plays a crucial part for the generation of self-awareness and our beliefs about function of body parts.Vorliegende Dissertation untersucht die Inzidenz und Diagnose sowie Läsionslokalisation der Anosognosie bei Schlaganfallpatienten. Hinsichtlich der Inzidenz und Diagnose wurden 128 Patienten mit Zustand nach Schlaganfall auf Anosognosie für Hemiparese mit einer Anosognosieskala nach Bisiach et al. (1986) untersucht. Es zeigte sich, daß 99 (77%) dieser Patienten ihr Defizit spontan erwähnten, 29 (23%) hatten entsprechend der Anosognosieskala eine milde, bzw. eine Anosognosie mittleren oder schweren Ausprägungsgrades, von denen hatten 17 (59%) einen Anosognosiegrad `1`, d. h. sie berichteten über ihr Defizit, wenn sie explizit nach der Kraft ihrer Extremitäten gefragt wurden. Die Untersuchung konnte jedoch zeigen, daß 94% von den Patienten mit Anosognosiegrad `1` (milder Anosognosie), unter anderen Defiziten wie Dysarthrie, Ptosis oder Cephalgie leideten. Diese Patienten erwähnten diese Defizite, wenn sie allgemein über ihre Beschwerden befragt wurden, jedoch erwähnten sie sofort ihren Kraftverlust der Extremität, wenn sie hinsichtlich einer Parese angesprochen wurden. Offensichtlich hatten diese Defizite eine größere Beeinträchtigung für diese Patienten als die Parese, zumal die Parese vorliegender Patienten leichter war, als bei der Patientengruppe mit Anosognosie mittleren oder schweren Ausprägungsgrades, d.h. bei den Patienten die auch nach expliziten Ansprechen ihrer Parese diese verneinten. Vorliegende Daten deuten darauf hin, daß Patienten mit &#65533;milder&#65533; Anosognosie, die ihre Parese sofort nachdem sie danach gefragt werden zugeben, nicht unbedingt als Anosognosiepatienten angesehen werden sollten. Wenn diese eher konservative Klassifikation angewendet wird, ergibt sich bei Anosognosie der Hemiparese eine Häufigkeit zwischen 10 und 18%. Dies wäre wesentlich weniger als ursprünglich berichtet. Hinsichtlich der Läsionlokalisation fanden sich bei überlagerten Läsionen von 14 Anosognosiepatienten im Vergleich zu den Läsionen von 13 Patienten der Kontrolgruppe, daß bei allen 14 Anosognosiepatienten die rechte posteriore Insel betroffen war. Es scheint, daß die rechte posteriore Insel ein anatomisches Korrelat für die Entstehung der Anosognosie der Hemiparese darstellen könnte