Biodiversity and global learning

"The United Nations declared 2010 the International Year of Biodiversity. This emphasis on the significance of biodiversity for human existence and well-being reveals just how important expanding biodiversity conservation really is. Against this background the question arises as to how much global learning can contribute to maintaining biodiversity." (author's abstract

The self in action - electrophysiological evidence for predictive processing of self-initiated sounds and its relation to the sense of agency

Stimuli caused by our own voluntary actions receive a special treatment in the brain. In auditory processing, the N1 and/or P2 components of the auditory event-related brain potential (ERP) to self-initiated sounds are attenuated compared to passive sound exposure, which has been interpreted as an indicator of a predictive internal forward mechanism. Such a predictive mechanism enables differentiating the sensory consequences of one´s own actions from other sensory input and allows the mind to attribute actions to agents and particularly to the self, usually called the “sense of agency”. However, the notion that N1 and/or P2 attenuation effects to self-initiated sounds reflect internal forward model predictions is still controversial. Furthermore, little is known about the relationship between N1 and/or P2 attenuation effects and the sense of agency. Thus, the aim of the present thesis was to further investigate the nature of the N1 and/or P2 attenuation effect to self-initiated sounds and to examine its specific relationship to the sense of agency. The present thesis provides evidence that N1 and/or P2 attenuation effects to self-initiated sounds are mainly determined by movement intention and predictive internal motor signals involved in movement planning and rules out non-predictive explanations of these effects. Importantly, it is shown that sensory attenuation effects in audition are directly related to the feeling of agency, but occur independent of agency judgments. Taken together, the present thesis supports the assumptions of internal forward model theories

Poröse Silica-basierte anorganisch-organische Netzwerke: Synthese, Charakterisierung und Anwendung neuer funktioneller Materialien

In dieser Dissertation konnte eine zweistufige Funktionalisierung von mesoporösen Silicamaterialien (im Besonderen SBA-15 und benzylverbrückten periodisch mesoporösen Organosilicas) mit einer photoschaltbaren Azobenzoleinheit etabliert werden. Der entscheidende Vorteil dieser zweistufigen Synthese ist die variable und exakt einstellbare Schalterdichte. Unter der Schalterdichte wird hierbei der Abstand zwischen zwei benachbarten, photoschaltbaren Einheiten verstanden. Die unterschiedlichen Schalterdichten wirken sich stark auf die Eigenschaften der azobenzolfunktionalisierten Silica-Materialien aus. So zeigt das Material mit dem in cis geschalteten Azobenzolschalter wesentlich stärkere attraktive Wechselwirkungen mit polaren Molekülen (Farbstoff oder Lösungsmittel) als das Material, das das trans-Isomer enthält. Bei den Materialien kann auch beobachtet werden, dass sich die unterschiedlichen Schalterdichten auf die Gleichgewichtseinstellung zwischen freigesetztem und eingelagertem Farbstoff auswirken. Weiterhin wurde die Bildung von PMO-Materialien im wässrigen Reaktionsmedium mit Hilfe einer in-situ-ATR-IR-Apparatur untersucht. Die Ergebnisse geben erstmals Einblicke in stufenweise Bildung solcher amorpher Hybridmaterialien. Außerdem konnten die empirisch gefundenen Syntheseparameter als fast optimal bestätigt werden bzw. kann durch kleine Veränderungen die Reaktion optimiert werden. Ein anderer Bereich dieser Arbeit beschäftigt sich mit dem Design potenter Photokatalysatoren. Es wurden poröse Silica-Materialien synthetisiert, die zum einen in der Porenwand verankerte Metallspezies und zum anderen Metallspezies auf der inneren und äußeren Oberfläche aufweisen

An Asymmetry in the Automatic Detection of the Presence or Absence of a Frequency Modulation within a Tone: A Mismatch Negativity Study

The infrequent occurrence of a transient feature (deviance; e.g., frequency modulation, FM) in one of the regular occurring sinusoidal tones (standards) elicits the deviance related mismatch negativity (MMN) component of the event-related brain potential. Based on a memory-based comparison, MMN reflects the mismatch between the representations of incoming and standard sounds. The present study investigated to what extent the infrequent exclusion of an FM is detected by the MMN system. For that purpose we measured MMN to deviances that either consisted of the exclusion or inclusion of an FM at an early or late position within the sound that was present or absent, respectively, in the standard. According to the information-content hypothesis, deviance detection relies on the difference in informational content of the deviant relative to that of the standard. As this difference between deviants with FM and standards without FM is the same as in the reversed case, comparable MMNs should be elicited to FM inclusions and exclusions. According to the feature-detector hypothesis, however, the deviance detection depends on the increased activation of feature detectors to additional sound features. Thus, rare exclusions of the FM should elicit no or smaller MMN than FM inclusions. In passive listening condition, MMN was obtained only for the early inclusion, but not for the exclusions nor for the late inclusion of an FM. This asymmetry in automatic deviance detection seems to partly reflect the contribution of feature detectors even though it cannot fully account for the missing MMN to late FM inclusions. Importantly, the behavioral deviance detection performance in the active listening condition did not reveal such an asymmetry, suggesting that the intentional detection of the deviants is based on the difference in informational content. On a more general level, the results partly support the “fresh-afferent” account or an extended memory-comparison based account of MMN

An asymmetry in the automatic detection of the presence or absence of a frequency modulation within a tone: a mismatch negativity study

The infrequent occurrence of a transient feature (deviance; e.g., frequency modulation, FM) in one of the regular occurring sinusoidal tones (standards) elicits the deviance related mismatch negativity (MMN) component of the event-related brain potential. Based on a memory-based comparison, MMN reflects the mismatch between the representations of incoming and standard sounds. The present study investigated to what extent the infrequent exclusion of an FM is detected by the MMN system. For that purpose we measured MMN to deviances that either consisted of the exclusion or inclusion of an FM at an early or late position within the sound that was present or absent, respectively, in the standard. According to the information-content hypothesis, deviance detection relies on the difference in informational content of the deviant relative to that of the standard. As this difference between deviants with FM and standards without FM is the same as in the reversed case, comparable MMNs should be elicited to FM inclusions and exclusions. According to the feature-detector hypothesis, however, the deviance detection depends on the increased activation of feature detectors to additional sound features. Thus, rare exclusions of the FM should elicit no or smaller MMN than FM inclusions. In passive listening condition, MMN was obtained only for the early inclusion, but not for the exclusions nor for the late inclusion of an FM. This asymmetry in automatic deviance detection seems to partly reflect the contribution of feature detectors even though it cannot fully account for the missing MMN to late FM inclusions. Importantly, the behavioral deviance detection performance in the active listening condition did not reveal such an asymmetry, suggesting that the intentional detection of the deviants is based on the difference in informational content. On a more general level, the results partly support the “fresh-afferent” account or an extended memory-comparison based account of MMN