• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 7
  • 5
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Examining morphological differences in Heschl's gyrus between neurotypical and dyslexic brains

Chin, Jamie A. 02 October 2020 (has links)
Current methods of diagnosis for developmental dyslexia rely on family history report and cognitive and language behavioral testing. However, relying on these measures alone to predict dyslexia in at-risk children can result in low sensitivity and specificity, with dyslexic individuals either being missed or over-identified. Prediction accuracy could be increased by considering structural differences in the dyslexic brain along with behavioral measures. Reduplication of Heschl’s gyrus, where the primary auditory cortex resides, has been suggested as a risk factor for developing dyslexia. The current investigation explored if differences in interhemispheric duplication patterns and gray matter volume of Heschl’s gyrus could distinguish between dyslexic and neurotypical (control) brains. A detailed labeling protocol based on macroanatomical landmarks and explicitly defined reduplication morphotypes: single Heschl’s gyrus (SH), common stem duplication (CSD), complete posterior duplication (CPD), and multiple duplication (MD) was developed. Overall, there was no significant difference in the incidence of morphotypes between control and dyslexic brains. Duplication of Heschl’s gyrus was a common occurrence in both groups. However, results suggest that the MD morphotype may occur more often in dyslexic brains. Gray matter volume of anterior Heschl’s gyrus was larger in the left hemisphere in both groups but tended to be larger overall in dyslexic brain. Results of this investigation confirmed the presence of high morphological variability between and within brains and suggest that reduplications in Heschl’s gyrus alone are not enough to designate between neurotypical and dyslexic brains. It is likely that developmental dyslexia has heterogeneous origins, and it is possible that increased gyrification combined with other structural differences is one possible origin.
2

Radar sounding of Lucus Planum, Mars, by MARSIS

Orosei, Roberto, Rossi, Angelo Pio, Cantini, Federico, Caprarelli, Graziella, Carter, Lynn M., Papiano, Irene, Cartacci, Marco, Cicchetti, Andrea, Noschese, Raffaella 07 1900 (has links)
Lucus Planum, extending for a radius of approximately 500km around 181 degrees E, 5 degrees S, is part of the Medusae Fossae Formation (MFF), a set of several discontinuous deposits of fine-grained, friable material straddling across the Martian highland-lowland boundary. The MFF has been variously hypothesized to consist of pyroclastic flows, pyroclastic airfall, paleopolar deposits, or atmospherically deposited icy dust driven by climate cycles. Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), a low-frequency subsurface-sounding radar carried by European Space Agency's Mars Express, acquired 238 radar swaths across Lucus Planum, providing sufficient coverage for the study of its internal structure and dielectric properties. Subsurface reflections were found only in three areas, marked by a distinctive surface morphology, while the central part of Lucus Planum appears to be made of radar-attenuating material preventing the detection of basal echoes. The bulk dielectric properties of these areas were estimated and compared with those of volcanic rocks and ice-dust mixtures. Previous interpretations that east Lucus Planum and the deposits on the northwestern flanks of Apollinaris Patera consist of high-porosity pyroclastic material are strongly supported by the new results. The northwestern part of Lucus Planum is likely to be much less porous, although interpretations about the nature of the subsurface materials are not conclusive. The exact origin of the deposits cannot be constrained by radar data alone, but our results for east Lucus Planum are consistent with an overall pyroclastic origin, likely linked to Tharsis Hesperian and Amazonian activity. Plain Language Summary Lobe-shaped thick deposits, collectively known as the Medusae Fossae Formation, are found west of the Olympus Mons volcano on Mars. Visual observations of these smooth and relatively unremarkably looking materials have not definitively determined how they formed with hypotheses ranging from volcanic ash to remnants of a materials deposited at a previous location of the north pole, to accumulation of atmospheric dust. In this study we used the ground penetrating radar on board Mars Express to see through these deposits to derive information about Lucus Planum, the central lobe of the Medusae Fossae Formation. Through our analysis of the way the radar waves were reflected by subsurface layering, we concluded that the materials forming Lucus Planum are spatially variable: the east and west portions of the deposits are highly porous and probably composed of ashes and rocks from nearby volcanoes. In the north-west the deposits are much denser, but we could not unequivocally define their nature. Finally, our instrument could not detect signals from the central part of Lucus Planum, which suggests yet a different component in the deposits. This diversity points to a dynamic geological history in this unique region of Mars.
3

Williams Syndrome: links between brain, cognition, and behaviour

Martens, Marilee A. Unknown Date (has links) (PDF)
The interrelationships between brain, cognition, and behaviour are complex but can be more clearly characterised by studying disorders with an underlying genetic basis. This thesis examined these interrelationships in the context of Williams syndrome (WS), a neurodevelopmental genetic disorder that affects aspects of cognition, behaviour, and brain structure. The principal aims of this thesis were to evaluate the cognitive, behavioural, and neuroanatomical profile of WS individuals and to explore the relationships between aspects of the cognitive and behavioural profile and the neuroanatomical changes that are evident in WS. Three general hypotheses, and 10 specific hypotheses, were postulated as a means of exploring these aims. The first general hypothesis predicted that WS individuals would demonstrate distinct features within their cognitive and behavioural profile. Specifically, it was predicted that WS individuals would show relative strengths on verbal tasks and significant deficits on visuospatial and mathematical tasks, in contrast to control participants who were predicted to show a more even profile. It was also predicted that WS individuals would show evidence of heightened affect in response to music and demonstrate hypersociability as compared to control participants
4

Williams Syndrome: links between brain, cognition, and behaviour

Martens, Marilee A. Unknown Date (has links) (PDF)
The interrelationships between brain, cognition, and behaviour are complex but can be more clearly characterised by studying disorders with an underlying genetic basis. This thesis examined these interrelationships in the context of Williams syndrome (WS), a neurodevelopmental genetic disorder that affects aspects of cognition, behaviour, and brain structure. The principal aims of this thesis were to evaluate the cognitive, behavioural, and neuroanatomical profile of WS individuals and to explore the relationships between aspects of the cognitive and behavioural profile and the neuroanatomical changes that are evident in WS. Three general hypotheses, and 10 specific hypotheses, were postulated as a means of exploring these aims. The first general hypothesis predicted that WS individuals would demonstrate distinct features within their cognitive and behavioural profile. Specifically, it was predicted that WS individuals would show relative strengths on verbal tasks and significant deficits on visuospatial and mathematical tasks, in contrast to control participants who were predicted to show a more even profile. It was also predicted that WS individuals would show evidence of heightened affect in response to music and demonstrate hypersociability as compared to control participants
5

Vergleichende MR- volumetrische Untersuchung des Planum temporale bei Schizophrenie, Bipolarer Störung, Zwangserkrankung und gesunden Kontrollpersonen / Vergleichende MR- volumetrische Untersuchung des Planum temporale bei Schizophrenie, Bipolarer Störung, Zwangserkrankung und gesunden Kontrollpersonen

Kremer, Lisa 19 November 2012 (has links)
No description available.
6

Approche empirico-eidétique de l'expérience musicale en sa constitution affective : une phénoménologie de la motricité musicale / An eidetic approach of affective constitution of musical experience

Tokay, Serâ 12 March 2015 (has links)
La phénoménologie, portant à l’expression une intuition eidétique de la spécificité de l’expérience musicale nourrie de la pratique quotidienne de l’instrument et de la fréquentation des œuvres du répertoire classique, doit pouvoir exercer, dans le dialogue avec les neurosciences, une double fonction : critique et positive. D’une part, elle est un révélateur des erreurs de catégorie des récents programmes de réduction de la musique, tantôt aux émotions de base, tantôt à la structure dynamique de la perception du temps, tantôt à un langage de communication non verbale. D’autre part, elle nous a servi à réorienter la recherche vers les conditions neurophysiologiques de l’immersion dans l’univers spirituel de Brahms (et des autres compositeurs) par projection intropathique d’une auto-affection kinesthésique, mettant l’écoute mélomane en résonance avec les tensions et relaxations musculaires du corps musicien accomplissant les gestes producteurs du «son musical». L’auteure, pianiste et chef d’orchestre, retirant l’enseignement philosophique de sa participation à l’équipe de neurophysiologistes du professeur Fadiga de l’Université de Ferrare, dont les travaux ont abouti à la publication d’un critère quantitatif de la «driving force» du chef d’orchestre applicable au jugement esthétique, pose les fondements d’une nouvelle eidétique kinesthésique de l’incarnation, l’empathie, l’intersubjectivité et la noématique musicale. L’anticipation, propriété fondamentale du vivant pour le physiologiste, la protention, structure de distensio animi de la conscience du temps pour le philosophe, sont à la base d’un principe technique intuitivement connu des grands chefs d’orchestre. / By giving expression to an eidetic intuition of the specificity of musical experience enriched by the daily practice of the instrument and familiarity with works from the classical repertoire, phenomenology, in its dialogue with the neurosciences, has to be able to fulfill a double function: both critical and positive. On the one hand, it brings to light the category mistakes inherent in recent programs seeking to reduce music either to basic emotions or else to the dynamic structure of the perception of time or again, to a non-verbal language of communication. On the other hand, it has made it possible for us to reorient ongoing research in the direction of an investigation of the neurophysiological conditions underlying the immersion into the spiritual universe of Brahms (and other composers), and this by way of an intropathic projection of a kinaesthetic auto-affection, establishing a resonance between the music-lovers auditive appreciation and the muscular tensions and relaxations of the musician body accomplishing the gestures productive of his ‘musical sound’. The author, a pianist and orchestral conductor, wants to lay the foundations for an eidetic investigation of our kinaesthetic experience of embodiment, of empathy, of intersubjectivity and of a musical noematics. The present work draws the philosophical lessons of her participation in a team of neurophysiologists, led by Professor Fadiga of the University of Ferrara, whose work led to the recent publication of a quantitative criterion of the driving force of conducting applicable to aesthetic judgment. Anticipation, one of the most fundamental properties of all living being for the physiologist, along with distensio animi, the structure of time consciousness for the philosopher, both lie at the root of a technical principle intuitively comprehended by the world’s great orchestral conductors.
7

The Origins of Four Paterae of Malea Planum, Mars

Larson, Susan K. 14 March 2007 (has links) (PDF)
Malea Planum is a volcanic plain on the southern rim of Hellas Planitia, the largest impact basin on Mars. Four large circular structures on Malea Planum have traditionally been identified as paterae, or low relief, central vent volcanoes (Plescia and Saunders, 1979). A geologic map was constructed and new crater counts made to explore the ages and origins of the paterae. Amphitrites and Peneus Paterae have radial patterns of wrinkle ridges on their flanks and distinct summit calderas (95 km and 130 km across) with arcuate bounding scarps. In contrast, Malea and Pityusa Paterae are broad depressions with diameters greater than 400 km. In some ways Pityusa and Malea Paterae resemble old, filled impact craters (Plescia, 2003) but they also have characteristics of volcanic subsidence features (Roche et al., 2000). A very strong positive gravity anomaly is centered over Amphitrites and smaller positive anomalies are associated with Peneus and Malea Paterae. A slight annular positive anomaly is associated with Pityusa. The geology of the Malea Planum Region has been influenced by impact cratering, volcanic, tectonic, fluvial, and most recently, eolian processes. The Noachian was dominated by impact cratering, the formation of Hellas Basin, and the eruption of flood lavas. Malea Planum formed during the mid- to late-Noachian, likely the result of sills liquefying the volatile-rich crust. Malea and Pityusa Paterae formed during the late Noachian. The Hesperian was marked by the formation of Peneus and Amphitrites and complex valley networks. During the mid-Hesperian, southern Malea Planum may have been covered by a very thick polar mantle deposit that melted and sublimated during the late Hesperian. Smaller episodes of polar mantle deposition continued through the Amazonian to the present. The Amazonian is also characterized by eolian activity creating dune fields, etched surfaces, and dust devil tracks. Based on the topographic and geophysical evidence, Amphitrites and Peneus are typical highland paterae. We conclude that a mid-crustal sill complex similar to that thought to exist beneath the eastern Snake River Plain in Idaho may be the best explanation for the formation of Malea and Pityusa Paterae. A lack of associated flow features on the surface suggests that the loads are the result of an accumulation of dense intrusions. A surficial load (e.g., lava flows) is insufficient to cause the amount of subsidence observed. A mid-crustal mafic or ultra-mafic sill or a dense network of sills and dikes may have contributed to the subsidence.

Page generated in 0.046 seconds