418 research outputs found
Essays on linguistic realism/ edited by Christina Behme, Mount Saint Vincent University ; Martin Neef, TU Braunschweig.
No full textIncludes bibliographical references and index.1 online resource
Speech dynamics are coded in the left motor cortex in fluent speakers but not in adults who stutter
No full textThe precise excitability regulation of neuronal circuits in the primary motor cortex is central to the successful and fluent production of speech. Our question was whether the involuntary execution of undesirable movements, e.g. stuttering, is linked to an insufficient excitability tuning of neural populations in the orofacial region of the primary motor cortex. We determined the speech-related time course of excitability modulation in the left and right primary motor tongue representation. Thirteen fluent speakers (four females, nine males; aged 23–44) and 13 adults who stutter (four females, nine males, aged 21–55) were asked to build verbs with the verbal prefix ‘auf’. Single-pulse transcranial magnetic stimulation was applied over the primary motor cortex during the transition phase between a fixed labiodental articulatory configuration and immediately following articulatory configurations, at different latencies after transition onset. Bilateral electromyography was recorded from self-adhesive electrodes placed on the surface of the tongue. Off-line, we extracted the motor evoked potential amplitudes and normalized these amplitudes to the individual baseline excitability during the fixed configuration. Fluent speakers demonstrated a prominent left hemisphere increase of motor cortex excitability in the transition phase (P = 0.009). In contrast, the excitability of the right primary motor tongue representation was unchanged. Interestingly, adults afflicted with stuttering revealed a lack of left-hemisphere facilitation. Moreover, the magnitude of facilitation was negatively correlated with stuttering frequency. Although orofacial midline muscles are bilaterally innervated from corticobulbar projections of both hemispheres, our results indicate that speech motor plans are controlled primarily in the left primary speech motor cortex. This speech motor planning-related asymmetry towards the left orofacial motor cortex is missing in stuttering. Moreover, a negative correlation between the amount of facilitation and stuttering severity suggests that we discovered a main physiological principle of fluent speech production and its role in stuttering
Schriftlinguistik
No full textNeef M, Sahel S, Weingarten R, eds. Schriftlinguistik. Berlin: De Gruyter; 2024
Effects on recovery during, acidosis in cardiac myocytes overexpressing CaMKII
No full textRecovery of intracellular Ca transients and fractional shortening during late phase acidosis are suggested to be associated with CaMKII-dependent processes of which phospholamban (PLB) phosphorylation may play an important role. To test whether increased expression levels of CaMKII may further enhance recovery, we investigated myocytes from CaMKII delta(C) transgenic (TG) mice (cytosolic localized CaMKII) having heart failure vs. wildtype littermates (WT). Furthermore, mouse and rabbit myocytes overexpressing CaMI:I delta(C) using adenovirus-mediated gene transfer (vs. LacZ control) were investigated. Fractional shortening (% vs. resting cell length, % RCL was assessed during control conditions (pH 7.4) and during acidosis (pH 6.5). Ca transients were measured using fluo-3 (Delta F/F-0, 10 mu M). In WT mouse myocytes, fractional shortening clearly recovered by 90% from 4.6 +/- 0.6 to 7.2 +/- 0.7% RCL during late acidosis. In parallel, Ca transients increased from 2.01 +/- 0. 11 to 2.33:L 0. 15 Delta F/F-0. When blocking CaMKII (KN-93, I mu M), recovery of Ca transients and shortening could be completely abolished, In contrast, in CaMKII delta(C) TG mouse myocytes shortening recovered only by 32% from 3.4 +/- 0.6 to 4.4 +/- 0.5% RCL (P< 0.05 vs. WT using ANOVA). In parallel, Ca transients increased only slightly from 1.75 +/- 0.15 to 1.84 +/- 0.13 Delta F/F-0 (P< 0.05 vs. WT using ANOVA). In accordance, SR Ca content (measured by caffeine contractures, 10 mM) in WT significantly increased during late acidosis but not in CaMKII delta(C) TG mice. In contrast, in mouse and rabbit myocytes overexpressing CaMKII delta(C) by means of adenovirus-mediated gene transfer, recovery of fractional shortening and Ca transients was not impaired during late acidosis but even slightly improved vs. LacZ control (P<0.05 vs. CaMKII delta(C) using ANOVA for mouse and rabbit myocytes). This was associated with significantly increased SR Ca content during late acidosis in CaMKII delta(C) as compared to LacZ. CaMKII-dependent PLB Thr- 17 phosphorylation, contributing to increased SR Ca uptake, was significantly increased in CaMKII delta(C) transfected rabbit myocytes vs. LacZ in the light of unchanged SR Ca ATPase and PLB protein expression. CaMKII inhibition completely prevented recovery of all parameters in both CaMKII delta(C) and LacZ. In summary and in contrast to our initial hypothesis, we showed for the first time that TG CaMKII delta(C) overexpression (i.e., chronic overexpression) in mice with heart failure clearly resulted in impaired recovery associated with impaired SR Ca loading during late acidosis vs. WT. This may be due to decreased SR Ca ATPase and PLB expression as reported previously. In contrast, adenovirus-mediated gene transfer of CaMKII delta(C) in mouse and rabbit myocytes (i.e., acute overexpression) did not result in impaired but even slightly improved recovery associated with increased SR Ca load during late acidosis as compared to LacZ. This most likely was due to higher PLB Thr- 17 phosphorylation in CaMKII delta(C) myocytes. In conclusion, possible beneficial effects by therapeutical CaMKII delta(C) stimulation on the ability to recover from acidosis may be challenged by altered expression levels of its target proteins and should be carefully considered. (c) 2007 Elsevier Inc. All rights reserved
Reduced Speech Perceptual Acuity for Stop Consonants in Individuals Who Stutter
No full textPurpose: In individuals who stutter (IWS), speech fluency can be enhanced by altered auditory feedback, although it has adverse effects in control speakers. This indicates abnormalities in the auditory feedback loop in stuttering. Current motor control theories on stuttering propose an impaired processing of internal forward models that might be related to a blurred auditory-to-motor translation. Although speech sound perception is an essential skill to form internal models, perceptual acuity has not been studied in IWS so far. The authors tested the stability of phoneme percepts by analyzing participants' ability to identify voiced and voiceless stop consonants. Method: Two syllable continua were generated by systematic modification of the voice onset time. The authors determined speech perceptual acuity by means of discriminatory power in 25 IWS and 24 matched control participants by determining the phoneme boundaries and by quantifying the interval of voice onset times for which phonemes were perceived ambiguously. Results: In IWS, discriminatory performance was weaker and less stable over time when compared with control participants. In addition, phoneme boundaries were located at longer voice onset times in IWS. Conclusion: Persistent developmental stuttering is associated with less reliable phonological percepts, supporting current theories regarding the sensory-motor interaction in human speech
The method of instructing children rationally in the arts of writing and reading. By J. Neef.
No full text338 p
Measuring graphematic transparency
No full textIn this article, a quantitative method to calculate the graphematic transparency of an alphabetic writing system is suggested. Graphematic transparency is a part of the traditional concept of orthographic depth, dealing with the direction from written representation to phonological representation only. Based on a thorough analysis of German graphematics given in Neef (2005a) and a tentative analysis of Italian graphematics, the respective gt-values are calculated in a constant theoretical framework. As expected, the gt-value for Italian is lower than that for German. For assessing the relevance of these calculated gt-values, further analyses of other writing systems are necessary. Keywords: orthographic depth; graphematic transparency; graphematics; typology; correspondence rule; phonological filter; geminate; German; Italian</jats:p
The Effect of Pension Generosity on Early Retirement: A Microdata Analysis for Europe from 1967 to 2004
No full textUsing pseudo-panel microdata we show that pension generosity affects early retirement decisions. The changes in the average replacement rate and decreases in wealth accrual between 1967 and 2004 have caused an increase in early retirement probabilities from 16% to 63%.Early Retirement; Pension Systems; Pension Neutrality; Pension Generosity; SHARE
Manfred Max Neef y la revolución ambientalista para América Latina, 1932-2019 (in memoriam)
No full textWith the article, it is offered a tribute to the work of Manfred Max Neef, Chilean intellectual,
politician, ecologist and economist, Alternative Nobel Prize winner in Economics, a pioneer in ecological
criticism of both productivism and extractivism in Latin America. The methodology used in this work
is based on the review of the main books published by the author, such as Barefoot Economy (1982),
Development on a Human Scale (1986), The Lost Dimension (2007), and The Unmasked Economy
(2014). It is held as an assumption that Max Neef’s work fits into a Latin American theoretical body,
which breaks intellectually with macroeconomic models, be they developmentalist or neoliberal in
nature. The originality of his contribution is in the defense of the ecological foundations for human
development at a local scale.Con el artículo, se ofrece un homenaje a la obra de Manfred Max Neef, intelectual, político, eco-
logista y economista chileno, Premio Nobel Alternativo en Economía, pionero en la crítica ecológica,
tanto en el productivismo como en el extractivismo en América Latina. La metodología empleada
en este trabajo se funda en la revisión de los principales libros publicados por el autor, tales como
Economía descalza (1982), Desarrollo a escala humana (1986), La dimensión perdida (2007) y La
economía desenmascarada (2014). Se sostiene como supuesto que la obra de Max Neef se encuadra
en un cuerpo teórico latinoamericano, que rompe intelectualmente con los modelos macroeconómi-
cos, sean de corte desarrollista o de tipo neoliberal. La originalidad de su aporte se encuentra en la
defensa de los fundamentos ecológicos para el desarrollo humano a una escala local
Left posterior-dorsal area 44 couples with parietal areas to promote speech fluency, while right area 44 activity promotes the stopping of motor responses
No full textAbstractArea 44 is a cytoarchitectonically distinct portion of Broca's region. Parallel and overlapping large-scale networks couple with this region thereby orchestrating heterogeneous language, cognitive, and motor functions. In the context of stuttering, area 44 frequently comes into focus because structural and physiological irregularities affect developmental trajectories, stuttering severity, persistency, and etiology. A remarkable phenomenon accompanying stuttering is the preserved ability to sing. Speaking and singing are connatural behaviours recruiting largely overlapping brain networks including left and right area 44. Analysing which potential subregions of area 44 are malfunctioning in adults who stutter, and what effectively suppresses stuttering during singing, may provide a better understanding of the coordination and reorganization of large-scale brain networks dedicated to speaking and singing in general. We used fMRI to investigate functionally distinct subregions of area 44 during imagery of speaking and imaginary of humming a melody in 15 dextral males who stutter and 17 matched control participants. Our results are fourfold. First, stuttering was specifically linked to a reduced activation of left posterior-dorsal area 44, a subregion that is involved in speech production, including phonological word processing, pitch processing, working memory processes, sequencing, motor planning, pseudoword learning, and action inhibition. Second, functional coupling between left posterior area 44 and left inferior parietal lobule was deficient in stuttering. Third, despite the preserved ability to sing, males who stutter showed bilaterally a reduced activation of area 44 when imagine humming a melody, suggesting that this fluency-enhancing condition seems to bypass posterior-dorsal area 44 to achieve fluency. Fourth, time courses of the posterior subregions in area 44 showed delayed peak activations in the right hemisphere in both groups, possibly signaling the offset response. Because these offset response-related activations in the right hemisphere were comparably large in males who stutter, our data suggest a hyperactive mechanism to stop speech motor responses and thus possibly reflect a pathomechanism, which, until now, has been neglected. Overall, the current results confirmed a recently described co-activation based parcellation supporting the idea of functionally distinct subregions of left area 44
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