34 research outputs found
Ist sprachliche Bedeutung präskriptiv?
Weist uns die Bedeutung sprachlicher Ausdrücke an, wie wir diese verwenden sollen? Die These, dass sprachliche Bedeutung normativ ist, wird seit Saul Kripkes Wittgenstein on Rules and Private Language genauso heftig vertreten wie bestritten und findet sich vor allem in zwei Ausformungen wieder: Zum einen wird bereits den Bedingungen, unter denen ein Wort richtig angewendet wird, normative Kraft zugesprochen. Zum anderen wird postuliert, dass Worte erst dadurch Bedeutung (und damit Bedingungen der richtigen Anwendung) bekommen, indem sie in einer von Normen geleiteten Praxis Anwendung finden. In beiden Fällen hat die Semantik normative Konsequenzen, denen jede Bedeutungstheorie Rechnung tragen muss.
Normativitätsgegner bestehen darauf, dass die Semantik bloß deskriptive Regeln enthält. Eine Kritik ihrer wichtigsten Einwände im ersten und zweiten Teil zeigt aber, dass ihre Argumente nicht unbedingt überzeugen: Kann sinnvoll verlangt werden, dass semantische Normen unumstößlich gelten, völlig willensunabhängig sind oder nicht-konstitutiv sind? Verstoßen semantische Normen tatsächlich gegen die Grundsätze, dass Sollen ein Entsprechen-Können und ein Dagegen-Verstoßen-Können impliziert? Noch dazu gehen Gegner und Befürworter von unterschiedlichen Vorstellungen von Korrektheit und Normativität aus. Es wird sich herausstellen, dass sowohl Befürworter als auch Gegner auf metaethischen Prämissen aufbauen. Ob man der semantischen Normativitätsthese folgt, hängt also vorrangig von der grundsätzlichen Vorstellung von Sollen ab. Im letzten Teil werden deshalb beispielhaft zwei aktuelle, sehr unterschiedliche, normative Theorien untersucht, nämlich von Alan Millar und Ralph Wedgwood. Dabei werden sich die Probleme normativer Theorien von zwei Perspektiven zeigen und damit ein Dilemma offenbaren: auf der einen Seite die Idee, dass Sollen ein notwendiges Erklärungswerkzeug menschlicher Handlungen darstellt, auf der anderen Seite die Schwierigkeiten metaethischer Argumentationen und der inhaltlichen Begründbarkeit von Normativität.Does the meaning of words and sentences tell us, how we ought to use them? At least since Saul Kripke’s Wittgenstein on Rules and Private Language many philosophers find irresistible the claim that linguistic meaning is normative, in two distinct ways: On the one hand, semantic normativity could directly derive from the simple fact that meaningful expressions have conditions of correct and incorrect use. On the other hand, the meaning of words (and so their correctness conditions) is said to be determined by norms, which govern our communal linguistic practice. In both cases, a semantic theory has to accommodate these normative requirements.
But the normativity thesis has also invited some suspicion. Antinormativists insist on the mere descriptive nature of semantic rules. They argue that linguistic meaning is not prescriptive because it is not categorical, because it can be overridden by desire and because it cannot be constitutive. Moreover, it is supposed to violate the principles that ought implies can-do and that ought implies can-do-otherwise. A detailed critique of these arguments in the first two parts of this paper shows that proponents and opponents have different conceptions of correctness and normativity and do not share the same metaethical presumptions. Thus, the normativity thesis is primarily dependent on those controversial issues. The last part of this paper, therefore, will examine two recent normative theories, namely by Alan Millar and Ralph Wedgwood. This juxtaposition will reveal a dilemma: the notion that normativity is a necessary tool for explaining human action on the one side, the insurmountable troubles of explaining and justifying normativity on the other
Raumnavigation in realer Umgebung - eine distinkte höhere Hirnleistung als sensitiver Indikation für eine rechtsseitige Hippocampusdysfunktion
Visual snow syndrome after start of citalopram-novel insights into underlying pathophysiology
Purpose!#!Chronic pain is common in the older population and a significant public health concern. However, comprehensive studies on analgesics use in this age group from Germany are scarce. This study aims to give a comprehensive overview on the use of the most common therapeutic groups of analgesics in community-dwelling older adults from Germany.!##!Methods!#!A cross-sectional study was carried out using data from a German cohort of 2038 community-dwelling adults aged 63-89Â years. Descriptive statistics and logistic regression models were applied to assess the utilization of analgesics by age, sex, pain severity, pain duration, and locations.!##!Results!#!One out of four study participants was suffering from high-intensity or disabling pain. Approximately half of those taking analgesics still reported to suffer from high-intensity or disabling pain. Among analgesics users, occasional non-steroidal anti-inflammatory drugs (NSAIDs) use was the most frequent pain therapy (in 43.6% of users), followed by metamizole (dipyrone) use (16.1%), regular NSAIDs use (12.9%), strong opioids use (12.7%), and weak opioids use (12.0%). In multivariate logistic regression models, higher age, higher pain severity, longer pain duration, abdominal pain, and back pain were statistically significantly associated with opioids use. Metamizole use was also statistically significantly associated with higher pain severity but inversely associated with pain duration.!##!Conclusions!#!A significant number of older German adults are affected by high-intensity and disabling chronic pain despite receiving analgesics. Long-term studies are needed to compare the effectiveness and safety of different treatments for chronic pain in older adults
A unique MRI-pattern in alcohol-associated Wernicke encephalopathy
There have been concerns about high rates of thus far undiagnosed SARS-CoV-2 infections in the health-care system. The COVID-19 Contact (CoCo) Study follows 217 frontline health-care professionals at a university hospital with weekly SARS-CoV-2-specific serology (IgA/IgG). Study participants estimated their personal likelihood of having had a SARS-CoV-2 infection with a mean of 21% [median 15%, interquartile range (IQR) 5-30%]. In contrast, anti-SARS-CoV-2 IgG prevalence was about 1-2% at baseline. Regular anti-SARS-CoV-2 IgG testing of health-care professionals may aid in directing resources for protective measures and care of COVID-19 patients in the long run
Reflexive and Intentional Saccadic Eye Movements in Migraineurs
Background: Migraine has been postulated to lead to structural and functional changes of different cortical and subcortical areas, including the frontal lobe, the brainstem, and cerebellum. The (sub-)clinical impact of these changes is a matter of debate. The spectrum of possible clinical differences include domains such as cognition but also coordination. The present study investigated the oculomotor performance of patients with migraine with and without aura compared to control subjects without migraine in reflexive saccades, but also in intentional saccades, which involve cerebellar as well as cortical networks.
Methods: In 18 patients with migraine with aura and 21 patients with migraine without aura saccadic eye movements were recorded in two reflexive (gap, overlap) and two intentional (anti, memory) paradigms and compared to 25 controls without migraine.
Results: The main finding of the study was an increase of saccade latency in patients with and without aura compared to the control group solely in the anti-task. No deficits were found in the execution of reflexive saccades.
Conclusions: Our results suggest a specific deficit in the generation of correct anti-saccades, such as vector inversion. Such processes are considered to need cortical networks to be executed correctly. The parietal cortex has been suggested to be involved in vector inversion processes but is not commonly described to be altered in migraine patients. It could be discussed that the cerebellum, which is recently thought to be involved in the pathophysiology of migraine, might be involved in distinct processes such as spatial re-mapping through known interconnections with parietal and frontal cortical areas
Age- and frequency-dependent changes in dynamic contrast perception in visual snow syndrome
OBJECTIVE Patients with visual snow syndrome (VSS) suffer from a debilitating continuous (\textquotedblTV noise-like\textquotedbl) visual disturbance. They report problems with vision at night and palinopsia despite normal visual acuity. The underlying pathophysiology of VSS is largely unknown. Currently, it is a clinical diagnosis based on the patient's history, an objective test is not available. Here, we tested the hypothesis that patients with VSS have an increased threshold for detecting visual contrasts at particular temporal frequencies by measuring dynamic contrast detection-thresholds. METHODS Twenty patients with VSS were compared to age-, gender-, migraine- and aura-matched controls in this case-control study. Subjects were shown bars randomly tilted to the left or right, flickering at six different frequencies (15 Hz, 20 Hz, 25 Hz, 30 Hz, 35 Hz, 40 Hz). The contrast threshold (CT) for detection of left or right tilt was measured in a two-alternative adaptive forced-choice procedure (QUEST). The threshold was defined as the Michelson contrast necessary to achieve the correct response in 75% of the cases. RESULTS The CT increased for higher flicker frequencies (ANOVA: main effect frequency: F (5,180) = 942; p < 0.001), with an additional significant frequency*diagnosis interaction (ANOVA: F (5,180) = 5.00; p < 0.001). This interaction effect was due to an increased CT at a flicker frequency of 15 Hz in the VSS cohort (VSS: MC = 1.17%; controls: MC = 0.77%). At the other frequencies, group comparisons revealed no differences. Furthermore, in the VSS cohort we observed an increase of CT with higher age (r = 0.69; p < 0.001), which was not seen in controls (r = 0.30; p = 0.20). CONCLUSIONS This study demonstrates a lower visual contrast sensitivity exclusively at 15 Hz in VSS patients and demonstrates frequency-dependent differences in dynamic contrast vision. The peak sensitivities of both parvo- and magnocellular visual pathways are close to a frequency of about 10 Hz. Therefore, this frequency seems to be of crucial importance in everyday life. Thus, it seems plausible that the impairment of contrast sensitivity at 15 Hz might be an important pathophysiological correlate of VSS. Furthermore, the overall age-related decrease in contrast sensitivity only in VSS patients underscores the vulnerability of dynamic contrast detection in VSS patients. Dynamic CT detection seems to be a promising neurophysiological test that may contribute to the diagnosis of VSS
Gait analysis in PSP and NPH Dual-task conditions make the difference
Objective To test whether quantitative gait analysis of gait under single- and dual-task conditions can be used for a differential diagnosis of progressive supranuclear palsy (PSP) and idiopathic normalpressure hydrocephalus (iNPH). Methods In this cross-sectional study, temporal and spatial gait parameters were analyzed in 38 patients with PSP (Neurological Disorders and Stroke and Society for Progressive Supranuclear Palsy diagnostic criteria), 27 patients with iNPH (international iNPH guidelines), and 38 healthy controls. A pressure-sensitive carpet was used to examine gait under 5 conditions: single task (preferred, slow, and maximal speed), cognitive dual task (walking with serial 7 subtractions), and motor dual task (walking while carrying a tray). Results The main results were as follows. First, both patients with PSP and those with iNPH exhibited significant gait dysfunction, which was worse in patients with iNPH with a more broad-based gait (p < 0.001). Second, stride time variability was increased in both patient groups, more pronounced in PSP (p = 0.009). Third, cognitive dual task led to a greater reduction of gait velocity in PSP (PSP 34.4% vs iNPH 16.9%, p = 0.002). Motor dual task revealed a dissociation of gait performance: patients with PSP considerably worsened, but patients with iNPH tended to improve. Conclusion Patients with PSP seem to be more sensitive to dual-task perturbations than patients with iNPH. An increased step width and anisotropy of the effect of dual-task conditions (cognitive vs motor) seem to be good diagnostic tools for iNPH
Bilateral vestibulopathy causes selective deficits in recombining novel routes in real space
The differential impact of complete and incomplete bilateral vestibulopathy (BVP) on spatial orientation, visual exploration, and navigation-induced brain network activations is still under debate. In this study, 14 BVP patients (6 complete, 8 incomplete) and 14 age-matched healthy controls performed a navigation task requiring them to retrace familiar routes and recombine novel routes to find five items in real space. 18F-fluorodeoxyglucose-PET was used to determine navigation-induced brain activations. Participants wore a gaze-controlled, head-fixed camera that recorded their visual exploration behaviour. Patients performed worse, when recombining novel routes (p < 0.001), whereas retracing of familiar routes was normal (p = 0.82). These deficits correlated with the severity of BVP. Patients exhibited higher gait fluctuations, spent less time at crossroads, and used a possible shortcut less often (p < 0.05). The right hippocampus and entorhinal cortex were less active and the bilateral parahippocampal place area more active during navigation in patients. Complete BVP showed reduced activations in the pontine brainstem, anterior thalamus, posterior insular, and retrosplenial cortex compared to incomplete BVP. The navigation-induced brain activation pattern in BVP is compatible with deficits in creating a mental representation of a novel environment. Residual vestibular function allows recruitment of brain areas involved in head direction signalling to support navigation
Diagnosis and follow-up evaluation of central nervous system vasculitis: an evaluation of vessel-wall MRI findings
OBJECTIVE To approach the clinical value of MRI with vessel wall imaging (VWI) in patients with central nervous system vasculitis (CNSV), we analyzed patterns of VWI findings both at the time of initial presentation and during follow-up. METHODS Stenoocclusive lesions, vessel-wall contrast enhancement (VW-CE) and diffusion-restricted lesions were analyzed in patients with a diagnosis of CNSV. On available VWI follow-up, progression, regression or stability of VW-CE were evaluated and correlated with the clinical status. RESULTS Of the 45 patients included, 28 exhibited stenoses visible on MR angiography (MRA-positive) while 17 had no stenosis (MRA-negative). VW-CE was found in 2/17 MRA-negative and all MRA-positive patients (p < 0.05). 79.1% (53/67) of stenoses showed VW-CE. VW-CE was concentric in 88.3% and eccentric in 11.7% of cases. Diffusion-restricted lesions were found more frequently in relation to stenoses with VW-CE than without VW-CE (p < 0.05). 48 VW-CE lesions in 23 patients were followed over a median time of 239.5~days. 13 VW-CE lesions (27.1%) resolved completely, 14 (29.2%) showed partial regression, 17 (35.4%) remained stable and 4 (8.3%) progressed. 22/23 patients received immunosuppressive therapy for the duration of follow-up. Patients with stable or progressive VW-CE were more likely (p < 0.05) to have a relapse (14/30 cases) than patients with partial or complete regression of VW-CE (5/25 cases). CONCLUSION Concentric VW-CE is a common finding in medium/large-sized vessel CNSV. VW-CE might represent active inflammation in certain situations. However, follow-up VWI findings proved ambiguous as persisting VW-CE despite immunosuppressive therapy and clinical remission was a frequent finding