@article{BellingerAltenmuellerVolkmann2017, author = {Bellinger, Daniel and Altenm{\"u}ller, Eckart and Volkmann, Jens}, title = {Perception of time in music in patients with Parkinson's disease - The processing of musical syntax compensates for rhythmic deficits}, series = {Frontiers in Neuroscience}, volume = {11}, journal = {Frontiers in Neuroscience}, doi = {10.3389/fnins.2017.00068}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-171805}, year = {2017}, abstract = {Objective: Perception of time as well as rhythm in musical structures rely on complex brain mechanisms and require an extended network of multiple neural sources. They are therefore sensitive to impairment. Several psychophysical studies have shown that patients with Parkinson's disease (PD) have deficits in perceiving time and rhythms due to a malfunction of the basal ganglia (BG) network. Method: In this study we investigated the time perception of PD patients during music perception by assessing their just noticeable difference (JND) in the time perception of a complex musical Gestalt. We applied a temporal discrimination task using a short melody with a clear beat-based rhythm. Among the subjects, 26 patients under L-Dopa administration and 21 age-matched controls had to detect an artificially delayed time interval in the range between 80 and 300 ms in the middle of the musical period. We analyzed the data by (a) calculating the detection threshold directly, (b) by extrapolating the JNDs, (c) relating it to musical expertise. Results: Patients differed from controls in the detection of time-intervals between 220 and 300 ms (*p = 0.0200, n = 47). Furthermore, this deficit depended on the severity of the disease (*p = 0.0452; n = 47). Surprisingly, PD patients did not show any deficit of their JND compared to healthy controls, although the results showed a trend (*p = 0.0565, n = 40). Furthermore, no significant difference of the JND was found according to the severity of the disease. Additionally, musically trained persons seemed to have lower thresholds in detecting deviations in time and syntactic structures of music (*p = 0.0343, n = 39). Conclusion: As an explanation of these results, we would like to propose the hypothesis of a time-syntax-congruency in music perception suggesting that processing of time and rhythm is a Gestalt process and that cortical areas involved in processing of musical syntax may compensate for impaired BG circuits that are responsible for time processing and rhythm perception. This mechanism may emerge more strongly as the deficits in time processing and rhythm perception progress. Furthermore, we presume that top-down-bottom-up-processes interfere additionally and interact in this context of compensation.}, language = {en} } @phdthesis{Bellinger2020, author = {Bellinger, Daniel}, title = {Zeitwahrnehmung in der Musik bei Morbus Parkinson - eine psychophysische Studie}, doi = {10.25972/OPUS-19876}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-198766}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Parkinson Patienten sind im Gegensatz zu gesunden Probanden in der kognitiven Verarbeitung zeitlicher Parameter, im Sinne einer Diskriminierungsf{\"a}higkeit f{\"u}r zeitliche Fehler innerhalb der Musikwahrnehmung beeintr{\"a}chtigt. Dies betrifft lediglich die Zeiterkennung in h{\"o}heren Intervallbereichen (> 600ms) und ist am ehesten durch Fluktuationen der Aufmerksamkeit, des Ged{\"a}chtnisses, aber auch im Vergleich zu anderen Studien durch methodische Ans{\"a}tze zu erkl{\"a}ren. Durch die Koppelung des Audiostimulus an klare Rhythmusstrukturen weist diese Studie jedoch darauf hin, dass {\"U}berschneidungen zu anderen neuronalen Netzwerken existieren, die zur Kompensationsstrategie rekrutiert und nutzbar gemacht werden k{\"o}nnen. Dazu geh{\"o}ren etwa die Verarbeitung zeitlicher (Cerebellum) und musikperzeptiver Leistungen, wie etwa die Verarbeitung musikalischer Syntax (BA 6, 22, 44). Etwaige Wahrnehmungsdefizite k{\"o}nnen durch Mechanismen musiksyntaktischer Verarbeitung kompensiert werden, da zeitliche und syntaktische Strukturen in der Musik auf ihre Kongruenz hin abgeglichen und somit multineuronal mediiert werden (Paradigma der Zeit-Syntax-Kongruenz in der Musikwahrnehmung). Weiterhin sind vermutlich top-down-bottom-up-Prozesse als multimodale Interaktionen an diesem Kompensationsmechanismus beteiligt. Außerdem ist festzuhalten, dass das Krankheitsstadium nicht zwangsl{\"a}ufig mit einem st{\"a}rkeren Wahrnehmungsdefizit f{\"u}r zeitliche Strukturen einhergehen muss, obwohl - wenn auch noch tolerabel - mit Progression der Erkrankung dieses Kompensationsmodell {\"u}ber Prinzipien der Gestaltwahrnehmung zusammenbricht und es hier zu schlechteren perzeptiven Leistungen kommen kann. Die Ergebnisse der OFF-Testungen und jener unter DBS-Therapie lassen weiterhin aufgrund der kleinen Stichprobe keine klare Aussage zu und machen weitere Untersuchungen notwendig. Das physiologische Alter korreliert außerdem mit der sensorischen Leistung, die allerdings starken, individuellen Unterschieden ausgesetzt ist und von multifaktoriellen Voraussetzungen abh{\"a}ngt. Auch zeigt die Studie, dass Menschen mit einem hohen Musikverst{\"a}ndnis und einer musikalischen Ausbildung ein feineres Diskriminierungsverm{\"o}gen in der zeitlichen Verarbeitung besitzen, welches v.a. im zeitlich niedrigen Intervallbereich (< 500ms) evident wird.}, subject = {Parkinson}, language = {de} } @phdthesis{Bellinger2016, author = {Bellinger, Daniel}, title = {Implementation of new reaction pathway determining methods and study of solvent effects on the excited state nature of perylene based dyes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144435}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2016}, abstract = {Two thematic complexes were addressed within this work. One part is related to improvements and new implementations into the CAST program package. Thereby the main focus laid on the delivery of a tool which can be used to characterize complex reactions and their mechanisms. But also within the new force field (FF) method (SAPT-FF) within the CAST program, several improvements were made. The second topic is related to the description of dye molecules and their spectral properties. The main focus within these studies was set on the influence of the environment on these properties. In the first topic improvements of the local acting NEB (nudged elastic band) methods were included and the number of available methods was extended. The initial pathway generation was improved by implementing the IDPP (image dependent pair potential) method and a new method was implemented for describing temperature dependent pathways. Additionally, improvements have been made to the optimization routines (global NEB). As a second part the Pathopt (PO) method was considerably improved. In the beginning of the work the original PO idea was used. In this approach one starts with a global optimization on one n-1 dimensional hyperplane which divides the reaction into two sub-areas for obtaining guesses of TSs (transition states). These found TS guesses were used to optimize to the "true" TS. Starting from the optimized ones a relaxation to the next connected minima is done. This idea has been automatically implemented and extended to several number of hyperplanes. In this manner a group of pathsegments is obtained which needs to be connected, but within this work it was realized that such a procedure might be not very efficient. Therefore, a new strategy was implemented which is founded on the same constrained global optimization scheme (MCM) for which the user defines the number of hyperplanes generated. The number of such generated hyperplanes should be large enough 134 to describe the space between the concerning reactants in a sufficient way. The found minima are directly used to built up the reaction pathway. For this purpose a RMSD (root mean square deviation) criterion is used to walk along ways of minimal change from one to another hyperplane. To prove the implementations various test calculations were carried out and extensions included to prove the capabilities of the new strategy. Related to these tests a new strategy for applying the move steps in MCM (Monte Carlo with minimization) was realized which is also related to the question of the coordinates representation. We were able to show that the hopping steps in MCM can be improved by applying Cartesian steps in combination of random dihedral moves with respect to the constraint. In this way it was possible to show that a large variety of systems can be treated. An additional chapter shows the improvements of the SAPT-FF implementation and related test cases. It was possible to treat benzene dimer and cluster systems of different sizes consistently also in accordance with high level ab initio based approaches. Furthermore, we showed that the SAPT-FF with the right parameters outperforms the standard AMOEBA implementation which is the basis of the SAPT-FF implementation. In the last three chapters deal with the description of perlyene-based dyes. In the first smaller chapter ground state chemistry description of macro cycles of PBI (perylene bisimide) derivatives were investigated. Therefore, AFM (atomic force microscopy) based pictures were explained within our study. The methods to explain aggregation behavior in dependency of the ring size were MD simulations and configuration studies. The last two chapters deal with opto-electronic or photo-physical properties of PBI and PTCDA (perylene-3,4,9,10-tetracarboxylic dianhydride). In detail, we investigated the role of the environment and the aggregate or crystal surrounding by applying different models. In that way implicit and explicit solvation models, the size of aggregates and vibration motions were used. In the case of PBI the recent work is found on preliminary studies related to my bachelor thesis and extends it. It was shown that the direct influence of a polarizable surrounding, as well as explicit inclusion of solvent molecules on the overall description of the excitations and nature of the excited states is weaker as one might expect. However the inclusion of intra-molecular degrees of freedom showed a stronger influence on the state characteristics and can induce a change of the order of states within the dimer picture. For the PTCDA molecule the main focus was set on the description of the absorption spectrum of crystalline thin films. Related to this older works exist which already gave a description and assignment of the absorption band, but are based on different approaches compared to the one used in this work. We used the supermolecule ansatz, whereas the environment and different aggregate sizes were investigated. Within the dimer based approach we were able to show that using continuum solvation (IEFPCM/COSMO) based description for the environment the relative order of states remains unchanged. Similar to the PBI calculations the influence of the vibrational motions /distortions is larger. The simulation of the crystal environment by using QM/MM (quantum mechanics/molecular mechanics) approaches delivered that an asymmetric charge distribution might induce a localization of the excitation and a stronger mixing of states. For obtaining further insights we go beyond the dimer picture and aggregates of different sizes were used, whereas the simulations up to the octadecamer mono- and even dual-layer stack were carried out. Within these calculations it was shown that the H-coupling is dominating over a weaker J-coupling between different stacks. Additionally the calculations based on DFT (density functional theory) and semi-empirics showed that the lowest state in terms of energy are mostly of Frenkel type, whereas the higher lying states are CT ones which mix with embedded Frenkel type states. The first band of the absorption spectrum was explained by inclusion of vibrational motions within the stacks which induce an intensity gain of the first excited state. This intensity was not explainable by using the undistorted stacks. Also relaxations at the crystal surface might play a role, but are experimentally not explainable.}, subject = {Globale Optimierung}, language = {en} }