TY - JOUR A1 - Muth, Felicitas V. A1 - Heilig, Michael A1 - Marquardt, Dorothea A1 - Mittelberg, Linda A1 - Sebald, Albrecht A1 - Kunde, Wilfried T1 - Lightness perception of structured surfaces JF - Color Research and Application N2 - Visual perception of surfaces is of utmost importance in everyday life. Therefore, it comes naturally, that different surface structures evoke different visual impressions in the viewer even if the material underlying these surface structures is the same. This topic is especially virulent for manufacturing processes in which more than one stakeholder is involved, but where the final product needs to meet certain criteria. A common practice to address such slight but perceivable differences in the visual appearance of structured surfaces is that trained evaluators assess the samples and assign a pass or fail. However, this process is both time consuming and cost intensive. Thus, we conducted two studies to analyze the relationship between physical surface structure parameters and participants visual assessment of the samples. With the first experiment, we aimed at uncovering a relationship between physical roughness parameters and visual lightness perception while the second experiment was designed to test participants' discrimination sensitivity across the range of stimuli. Perceived lightness and the measured surface roughness were nonlinearly related to the surface structure. Additionally, we found a linear relationship between the engraving parameter and physical brightness. Surface structure was an ideal predictor for perceived lightness and participants discriminated equally well across the entire range of surface structures. KW - surface structure KW - appearance KW - color perception KW - maximum likelihood difference scaling KW - psychophysics Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257314 VL - 47 IS - 2 ER - TY - THES A1 - Kretzer, Katharina T1 - Einfluss der Form elektrischer Impulse auf die intracochleäre neuronale Antwort bei Cochlea-Implantat-Trägern: triphasische Pulse mit anodischer und kathodischer zweiter Phase T1 - Influence of the shape of electrical pulses on the intracochlear neural response in cochlear implant recipients: triphasic pulses with anodic and cathodic second phase N2 - Vorliegende Arbeit beschäftigte sich mit der Verbesserung von Defiziten der elektrischen Stimulation durch Cochlea Implantate (CI) mit alternativen Pulsformen. Dabei wurde mit elektrophysiologischen und psychophysikalischen Methoden untersucht, wie sich die Pulsformen auf die Effektivität der Stimulation auswirken. Es wurden präzisions-triphasische Pulse (pTP) mit anodischer und kathodischer zweiter Phase anhand der Daten von elf Probanden untersucht. Im Rahmen der objektiven elektrophysiologischen Messung wurde mit den unterschiedlichen Formen des pTP an drei unterschiedlichen Kontaktpositionen auf den CI-Elektrodenträgern stimuliert, und die Stärke der jeweils evozierten neuronalen Antwort aufgezeichnet. Der subjektive psychophysikalische Test diente dazu, die pulsformspezifischen Hörschwellen zu bestimmen und wurde an zwei unterschiedlichen Kontakten auf den CI-Elektrodenträgern durchgeführt. Dabei erzielten pTP, welche eine symmetrisch-triphasische Pulsform aufwiesen, geringere neuronale Antwortstärken und höhere Hörschwellen als die pTP, die einer biphasischen Pulsform glichen. Diejenigen pTP, die biphasischen Pulsen mit anodischer erster Phase glichen, erzielten dabei die höchsten neuronalen Antwortstärken und die niedrigsten Hörschwellen. N2 - Present work dealt with the improvement of deficits of electrical stimulation by cochlear implants (CI) by means of alternative pulse shapes. This involved the use of electrophysiological und psychophysical methods to investigate the effect of pulse shape on the effectiveness of stimulation. Precision-triphasic pulses (pTP) with anodic and cathodic second phase were examined using data from eleven subjects. In the objective electrophysiological measurement, the different shapes of the pTP were stimulated from three different contact positions on the CI electrode arrays and the strength of the neural response evoked in each case was recorded. In the subjective psychophysical test, pTP stimulation was performed from two different contact positions on the CI electrode arrays and the pulse shape-specific detection thresholds were compared. The results showed that pTP, which exhibited a symmetric-triphasic pulse shape, achieved lower neuronal response strengths and higher detection thresholds than pTP that resembled a biphasic pulse shape. Those pTP, that resembled biphasic pulses with an anodic first phase, achieved the highest neuronal response strengths and the lowest detection thresholds. KW - Cochlear-Implantat KW - Elektrophysiologie KW - Psychophysik KW - elektrische Stimulation KW - cochlear implant KW - electrical stimulation KW - psychophysics KW - electrophysiology Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281650 ER - TY - JOUR A1 - Bellinger, Daniel A1 - Altenmüller, Eckart A1 - Volkmann, Jens T1 - Perception of time in music in patients with Parkinson's disease - The processing of musical syntax compensates for rhythmic deficits JF - Frontiers in Neuroscience N2 - 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. KW - Parkinson disease KW - psychophysics KW - time perception KW - rhythm perception KW - musical syntax KW - just noticeable difference (JND) Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171805 VL - 11 ER - TY - THES A1 - Bellinger, Daniel T1 - Zeitwahrnehmung in der Musik bei Morbus Parkinson - eine psychophysische Studie T1 - Perception of Time in Music in Patients with Parkinson's Disease – A Psychophysical Study N2 - Parkinson Patienten sind im Gegensatz zu gesunden Probanden in der kognitiven Verarbeitung zeitlicher Parameter, im Sinne einer Diskriminierungsfähigkeit für zeitliche Fehler innerhalb der Musikwahrnehmung beeinträchtigt. Dies betrifft lediglich die Zeiterkennung in höheren Intervallbereichen (> 600ms) und ist am ehesten durch Fluktuationen der Aufmerksamkeit, des Gedächtnisses, aber auch im Vergleich zu anderen Studien durch methodische Ansätze zu erklären. Durch die Koppelung des Audiostimulus an klare Rhythmusstrukturen weist diese Studie jedoch darauf hin, dass Überschneidungen zu anderen neuronalen Netzwerken existieren, die zur Kompensationsstrategie rekrutiert und nutzbar gemacht werden können. Dazu gehören etwa die Verarbeitung zeitlicher (Cerebellum) und musikperzeptiver Leistungen, wie etwa die Verarbeitung musikalischer Syntax (BA 6, 22, 44). Etwaige Wahrnehmungsdefizite können 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 zwangsläufig mit einem stärkeren Wahrnehmungsdefizit für zeitliche Strukturen einhergehen muss, obwohl – wenn auch noch tolerabel – mit Progression der Erkrankung dieses Kompensationsmodell über 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 abhängt. Auch zeigt die Studie, dass Menschen mit einem hohen Musikverständnis und einer musikalischen Ausbildung ein feineres Diskriminierungsvermögen in der zeitlichen Verarbeitung besitzen, welches v.a. im zeitlich niedrigen Intervallbereich (< 500ms) evident wird. N2 - 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. KW - Parkinson KW - Parkinson disease KW - psychophysics KW - Psychophysik KW - Musikwahrnehmung KW - Zeitwahrnehmung KW - Rhythmusperzeption KW - musikalische Syntax KW - time perception KW - rhythmperception KW - musical syntax KW - just noticeable difference (JND) Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-198766 N1 - s. a. Frontiers of Neuroscience. 2017 Feb 23;11:68. doi: 10.3389/fnins.2017.00068. eCollection 2017 ER -