Fenomenologia dell'improvvisazione musicale. La prospettiva del performer.

L\u2019improvvisazione musicale \ue8 una pratica che ha visto negli ultimi anni il fiorire di numerosi studi che tentano di indagarne le caratteristiche pi\uf9 importanti. L\u2019obiettivo di questo lavoro \ue8 descrivere le caratteristiche fenomenologiche dell\u2019atto improvvisativo dal punto di vista dell\u2019esecutore. In particolare, quali sono le caratteristiche strutturali del processo improvvisativo? Cosa s\u2019intende per nonlinearit\ue0 dell\u2019agire improvvisativo? E in che senso l\u2019atto improvvisativo \ue8 emergenziale? Per rispondere a queste domande si \ue8 adottato un punto di vista fenomenologico incentrato sulla figura del performer. Si \ue8 analizzato il processo improvvisativo comparando esperienze e pratiche musicali eterogenee, descrivendo e analizzando tali esperienze e pratiche. E' per questa ragione che lo svolgimento del percorso di ricerca comporta che la tematica della non-linearit\ue0 (di stampo musicologico) incontri proficuamente il concetto di invarianza (dalla provenienza ancor pi\uf9 ramificata: scientifica, matematica, psicologica e filosofica), e infine quello di emergenza. La visione fenomenologica che caratterizza il percorso argomentativo ha messo in risalto la forza descrittiva di tali categorie e le loro analogie verso una comprensione dell'atto improvvisativo dal punto di vista dell'esecutore. La prima parte della tesi indaga gli strumenti filosofici offerti dalla fenomenologia husserliana, utili per comprendere la nozione di suono in rapporto alla temporalit\ue0 della coscienza. La nozione di invarianza \ue8 utile per comprendere i problemi dell'identit\ue0 sonora e come questa assume importanza dal punto di vista fenomenologico per descrivere i processi improvvisativi. Nella seconda parte della tesi il concetto di invarianza \ue8 alla base della descrizione dell'atto improvvisativo e del rapporto fra linearit\ue0 e nonlinearit\ue0 dell'improvvisazione. Viene analizzato il concetto di \u201cinizio dell'improvvisazione\u201d e \u201cfine dell'improvvisazione\u201d. In ultima analisi, l'atto improvvisativo si mostra come un processo emergenziale di cui l'invarianza e la nonlinearit\ue0 ne sono gli ingredienti costitutivi. In ultima analisi l\u2019atto improvvisativo si viene a delineare come un atto della coscienza che ha una struttura emergenziale, ovvero invariante rispetto a trasformazioni improvvise, in altre parole il fluire in un presente continuamente emergente, rispetto a un\u2019attesa improvvisa e a una ritenzione sfuggente

Five Improvisations: aspetti nonlineari di un’improvvisazione

This article aims to show how it is possible to enrich our knowledge of music through a linear and nonlinear analysis of sound. For this purpose, 1. I conduct a nonlinear analysis of a specific improvised music for winds and percussion, 2. I describe the sound characteristics of the invariants present in the improvisation, and 3. I finally show the relationship between linear and nonlinear properties of music

Improvvisazione e non linearità. Riflessioni su “Oscillazioni”

Il rapporto fra nonlinearità e improvvisazione musicale grazie all'analisi e allo studio della partitura di un brano musicale che contiene segni musicali in notazione standard e grafica. Se l'uso della notazione musicale tradizionale veicola contenuti musicali fondamentalmente lineari, il segno grafico consente di aprire il campo all'improvvisazione e all'esecuzione di contenuti musicali nonlineari

Invarianza, tempo e improvvisazione musicale.

The notion of invariance permeates different research areas and often takes on different meanings. In different fields (psychology, phenomenology, physics, and ethics) the invariance concept attempts to explain the mechanisms of perceptual grouping. In this article invariance is considered a structural condition of our way of perceiving music and especially musical improvisation. It helps to understand the relationship between musical improvisation and nonlinearity, i.e. between what is transformed and what remains unchanged in the process of improvisation. I argue that every musical improvisation whose characteristics are nonlinear implies perceptual invariance with respect to time

Studying Alzheimer disease, Parkinson disease, and amyotrophic lateral sclerosis with 7-T magnetic resonance

Ultra-high-field (UHF) magnetic resonance (MR) scanners, that is, equipment operating at static magnetic field of 7 tesla (7 T) and above, enable the acquisition of data with greatly improved signal-to-noise ratio with respect to conventional MR systems (e.g., scanners operating at 1.5 T and 3 T). The change in tissue relaxation times at UHF offers the opportunity to improve tissue contrast and depict features that were previously inaccessible. These potential advantages come, however, at a cost: in the majority of UHF-MR clinical protocols, potential drawbacks may include signal inhomogeneity, geometrical distortions, artifacts introduced by patient respiration, cardiac cycle, and motion. This article reviews the 7 T MR literature reporting the recent studies on the most widespread neurodegenerative diseases: Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis

Epilepsy and phenylketonuria: a case description and EEG-fMRI findings.

Phenylketonuria (PKU) is characterized by phenylalanine accumulation due to phenylalanine hydroxylase deficiency. Up to 50% of PKU patients experience seizures. We evaluated an adult PKU patient who suffered from absences and primarily generalized tonicclonic seizures, associated with generalized spikeand-wave discharges (GSWs) on EEG. An analysis of blood oxygenation level-dependent (BOLD) signal changes during interictal epileptiform discharges showed early activation of the left perirolandic cortex followed by a BOLD signal decrease within cortical regions belonging to the default mode network and left frontoparietal cortex. Moreover, deactivation of the head of the right caudate nucleus and the left thalamus was observed. The fMRI pattern observed in our patient during GSWs is similar but not identical to that observed in idiopathic generalized epilepsy, suggesting different neurophysiological mechanisms. This is the first description of BOLD-fMRI patterns in a PKU patient with epilepsy. Similar studies in more patients might help to uncover the pathophysiology of seizures in this disease

Dependence of brain DTI maps of fractional anisotropy and mean diffusivity on the number of diffusion weighting directions

The rotational variance dependence of diffusion tensor imaging (DTI) derived parameters on the number of diffusion weighting directions (N) has been investigated by several Monte Carlo simulation studies. However, the dependence of fractional anisotropy (FA) and mean diffusivity (MD) maps on N, in terms of accuracy and contrast between different anatomical structures, has not been assessed in detail. This experimental study further investigated in vivo the effect of the number of diffusion weighting directions on DTI maps of FA and MD. Human brain FA and MD maps of six healthy subjects were acquired at 1.5T with varying N (6, 11, 19, 27, 55). Then, FA and MD mean values in high (FAH, MDH) and low (FAL, MDL) anisotropy segmented brain regions were measured. Moreover, the contrast-to-signal variance ratio (CVRFA, CVRMD) between the main white matter and the surrounding regions was calculated. Analysis of variance showed that FAL, FAH and CVRFA significantly (p 0.05) depend on N. Unlike MD values, FA values significantly vary with N. It is noteworthy that the observed variation is opposite in low and high anisotropic regions. In clinical studies, the effect of N may represent a confounding variable for anisotropy measurements and the employment of DTI acquisition schemes with high N (> 20) allows an increased CVR and a better visualization of white matter structures in FA maps

MRI cortical feature of bulbar impairment in patients with amyotrophic lateral sclerosis

The decline of voluntary bulbar functions such as speech and swallowing are among the clinical manifestations of amyotrophic lateral sclerosis (ALS) influencing a worst prognosis. Differential diagnosis between the contribution of upper motor neuron (UMN) and lower motor neuron degeneration to the bulbar impairment is often hard. Thinning and T2* hypointensity of the primary motor cortex have been recently suggested as possible MRI markers of UMN impairment in ALS patients, but little research has purposely targeted the orofacial region of the primary motor cortex (fM1). With the aim of finding an MRI marker of UMN impairment responsible for bulbar dysfunction, we investigated the T2* signal intensity of fM1 and the relationship with bulbar impairment in ALS patients. Fifty-five ALS patients were examined with 3 T MRI. Their fM1 was evaluated both qualitatively in terms of T2* signal intensity and quantitatively by measuring its magnetic susceptibility with Quantitative Susceptibility Mapping (QSM). Bulbar functions were assessed clinically, by neurological examination and using the items 1–3 of the ALSFRS-R, and with neurophysiological tests. The marked hypointensity of fM1 was detected in 25% of ALS patients, including all patients with bulbar onset, and was 74% sensitive, 100% specific and 91% accurate in diagnosing functional bulbar impairment. Such hypointensity involved the middle and ventral part of fM1 and was usually visible in both hemispheres. The magnetic susceptibility was significantly higher in patients with marked fM1 hypointensity than in the other patients (p ≤ .001). The relationship with clinical and neurophysiological data suggests that such feature could be a marker of UMN degeneration for voluntary bulbar functions

Bevacizumab for the Treatment of Radiation-Induced Cerebral Necrosis: A Systematic Review of the Literature

Radiation necrosis (RN) of brain tissue is a serious late complication of brain irradiation and recently bevacizumab has been suggested as treatment option of RN. There is a lack of data in the literature regarding the effectiveness of bevacizumab for the treatment of RN. The purpose of this review was to perform a comprehensive analysis of all reported cases using bevacizumab for the treatment of brain RN. In September 2016, we performed a comprehensive literature search of the following electronic databases: PubMed, Web of Science, Scopus and Cochrane Library. The research for the review was conducted using a combination of the keywords “radiation necrosis”, “radiotherapy” and “bevacizumab” alongside the fields comprising article title, abstract and keywords. Randomized trials, non-randomized trials, prospective studies, retrospective studies and single case reports were included in the review. Our research generated 21 studies and 125 cases where bevacizumab had been used for the treatment of RN. The median follow-up was 8 months and the most frequent bevacizumab dose used was 7.5 mg/kg for 2 weeks with a median of four cycles. Low-dose bevacizumab resulted in effectiveness with improvement in both clinical and radiographic response. The median decrease in T1 contrast enhancement and in T2/FLAIR signal abnormality was 64% and 60%, respectively. A reduction in steroidal therapy was observed in majority of patients treated. Based on the data of our review, bevacizumab appears to be a promising agent for the treatment of brain RN. Future prospective studies are required to evaluate the role of bevacizumab in RN and to define the optimal scheduling, dosage and duration of therapy

How concepts are encoded in the human brain: A modality independent, category-based cortical organization of semantic knowledge

Abstract How conceptual knowledge is represented in the human brain remains to be determined. To address the differential role of low-level sensory-based and high-level abstract features in semantic processing, we combined behavioral studies of linguistic production and brain activity measures by functional magnetic resonance imaging in sighted and congenitally blind individuals while they performed a property-generation task with concrete nouns from eight categories, presented through visual and/or auditory modalities. Patterns of neural activity within a large semantic cortical network that comprised parahippocampal, lateral occipital, temporo-parieto-occipital and inferior parietal cortices correlated with linguistic production and were independent both from the modality of stimulus presentation (either visual or auditory) and the (lack of) visual experience. In contrast, selected modality-dependent differences were observed only when the analysis was limited to the individual regions within the semantic cortical network. We conclude that conceptual knowledge in the human brain relies on a distributed, modality-independent cortical representation that integrates the partial category and modality specific information retained at a regional level