No description available.

In the human visual system, one of the most prominent functions of the extensive feedback from the higher brain areas within and outside of the visual cortex is attentional modulation. The feedback helps the brain to concentrate its resources on visual features that are relevant for recognition, i. e. it iteratively selects certain aspects of the visual scene for refined processing by the lower areas until the inference process in the higher areas converges to a single hypothesis about this scene. In order to minimize a number of required selection-refinement iterations, one has to find a short sequence of maximally informative portions of the visual input. Since the feedback is not static, the selection process is adapted to a scene that should be recognized. To find a scene-specific subset of informative features, the adaptive selection process on every iteration utilizes results of previous processing in order to reduce the remaining uncertainty about the visual scene. This phenomenon inspired us to develop a computational algorithm solving a visual classification task that would incorporate such principle, adaptive feature selection. It is especially interesting because usually feature selection methods are not adaptive as they define a unique set of informative features for a task and use them for classifying all objects. However, an adaptive algorithm selects features that are the most informative for the particular input. Thus, the selection process should be driven by statistics of the environment concerning the current task and the object to be classified. Applied to a classification task, our adaptive feature selection algorithm favors features that maximally reduce the current class uncertainty, which is iteratively updated with values of the previously selected features that are observed on the testing sample. In information-theoretical terms, the selection criterion is the mutual information of a class variable and a feature-candidate conditioned on the already selected features, which take values observed on the current testing sample. Then, the main question investigated in this thesis is whether the proposed adaptive way of selecting features is advantageous over the conventional feature selection and in which situations. Further, we studied whether the proposed adaptive information-theoretical selection scheme, which is a computationally complex algorithm, is utilized by humans while they perform a visual classification task. For this, we constructed a psychophysical experiment where people had to select image parts that as they think are relevant for classification of these images. We present the analysis of behavioral data where we investigate whether human strategies of task-dependent selective attention can be explained by a simple ranker based on the mutual information, a more complex feature selection algorithm based on the conventional static mutual information and the proposed here adaptive feature selector that mimics a mechanism of the iterative hypothesis refinement. Hereby, the main contribution of this work is the adaptive feature selection criterion based on the conditional mutual information. Also it is shown that such adaptive selection strategy is indeed used by people while performing visual classification.

In der vorliegenden Studie wurde die Hypothese geprüft, daß Asthmatiker die Aufmerksamkeit von eigenen Körperprozessen ablenken und eine Ungenauigkeit bei der Interozeption relevanter Atemwegsobstruktionen aufweisen. Weiterhin prüften wir die Frage, inwieweit die postulierte Aufmerksamkeitsabwendung generalisiert ist und sich auch auf die nicht atemwegsbezogene Symptomwahrnehmung und die private Selbstaufmerksamkeit bezieht. Die Interozeptionsgenauigkeit wurde als Diskrepanz zwischen subjektivem Urteil und objektiver Atemfunktion bei spirometrischen Messungen berechnet, die anderen Variablen mittels Fragebögen operationalisiert. Es wurden insgesamt 91 Patienten einer Rehabilitationseinrichtung untersucht: 30 Asthmatiker, 30 Patienten mit chronisch obstruktiver Bronchitis (COB) und 31 Kontrollpatienten ohne Atemwegserkrankung. Die Ergebnisse deuten auf eine spezifisch atemwegsbezogene Aufmerksamkeitsablenkung sowie eine Überschätzung von Obstruktionen bei Asthmatikern hin. Überraschend zeigen auch die COB-Patienten auffällige Ergebnismuster in Richtung einer Unterschätzung von Obstruktionen sowie verminderter Selbstaufmerksamkeit. Die Ergebnisse lassen sich im Rahmen verhaltensmedizinischer Überlegungen interpretieren. / The hypothesis that asthmatic patients draw their attention away from bodily processes and show inaccurate interoception with regard to relevant airway obstructions was tested in this study. Additionally, we examined whether this postulated withdrawal of attention can also be generalized for the perception of non-airway related symptoms as well as for private self-consciousness. Accuracy of interoception was measured as the discrepancy between subjective judgement of obstruction and objective obstruction as shown in spirometric tests. Other variables were operationalized by self-reports. Ninetyone patients in a rehabilitation hospital were tested: 30 asthmatic patients, 30 patients with chronic obstructive bronchitis (COB), and 31 control subjects without any airway disease. Asthmatic patients showed attention withdrawal only with regard to bronchial airways. However, they also indicated an overestimation of airway obstruction. Surprisingly, deviant results were also found for the COB patients including underestimation of obstructions and lower self awareness. All results were interpreted from the perspective of behavioral medicine. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Thesis (Ph.D.)--University of Bonn, Germany. / Includes bibliographical references and index.

Thesis (Ph.D.)--University of Bonn, Germany. / Includes bibliographical references and index. Also issued online.

Recently cognitive principles have been discussed for Conceptual Modeling with the aim to increase domain understanding, model comprehension and modeling efficiency. In particular, the principle of Perceptual Discriminability, which discusses the visual differences of modeling constructs, reveals potential for model comprehension if human attention is influenced in a way that important modeling constructs are more easily detected, and can hence faster be processed. Yet, so far no conditions how the human gaze can be influenced have been defined and evaluated for Conceptual Modeling. This dissertation extends Perceptual Discriminability for conditions to attract human attention for those constructs that are important for model comprehension. Furthermore, these conditions are applied to constructs of two different modeling grammars in general as well as to elements of the process flow of Business Process Models. To evaluate the results a laboratory experiment of extended Perceptual Discriminability is described in which significant differences have been identified for process flow comprehension. For the demonstration of the potential of extended Perceptual Discriminability BPMN secondary notation is improved by emphasizing those constructs that are most important for model comprehension. Therefore, those constructs that are important for model comprehension have been identified within a content analysis and have been worked on according to the conditions of extended Perceptual Discriminability for those visual variables that are free for an application in secondary notation.

Abstract This study demonstrates the various facets of mediality in post-1945 German-language literature, using as examples seven works of prose by Nicolas Born, Ingeborg Bachmann, Peter Handke, Bodo Morshäuser, Uwe Johnson, Heinrich Böll and Martin Walser. The thesis is divided into two major sections: a theoretical section and a text-oriented research section. In the theoretical section, a positioning of media and literature is carried out in the context of history and the history of literature. Starting from the relationship between fiction and reality, a distinction is made between generative and classical mediality. In the research section, mediality in literature is analyzed under the following three thematic criteria: “attention”, “distance” and “reality”; each criterion is addressed using two works of prose as examples. The relatedness of these criteria is analyzed on the basis of the seventh book. This study reveals the diversity of the layers of mediality in the literature of the era and places the individual works of prose in an over-all literary context. / Abstract Die Untersuchung zeigt am Beispiel von sieben Prosawerken von Nicolas Born, Ingeborg Bachmann, Peter Handke, Bodo Morshäuser, Uwe Johnson, Heinrich Böll und Martin Walser verschiedene Facetten von Medialität in der deutschsprachigen Literatur nach 1945. Die Arbeit gliedert sich in einen theoretischen und einen textbezogenen Teil. Im theoretischen Teil wird eine Positionierung von Medien und Literatur in einem historischen und literaturgeschichtlichen Kontext vorgenommen. Ausgehend von der Fiktionsfrage wird eine Unterscheidung zwischen generativer und klassischer Medialität vorgenommen. Im textbezogenen Teil wird die Frage nach der Medialität in der Literatur unter den drei thematischen Schwerpunkten „Aufmerksamkeit”, „Distanz” und „Wirklichkeit” abgehandelt, wobei jeweils zwei Prosawerke zur Geltung gebracht werden. Die Bezüge zwischen diesen Schwerpunkten werden an einem siebten Prosawerk untersucht. Die Untersuchung zeigt die Vielfalt der Medialitätsschichten in der Literatur der Zeit und gestattet eine Positionierung der einzelnen Werke im gesamtliterarischen Kontext. / Tiivistelmä Tutkimus osoittaa mediaalisuuden erilaiset mahdollisuudet seitsemän proosateoksen avulla vuoden 1945 jälkeisessä saksankielisessä kirjallisuudessa. Tutkimus jakaantuu teoreettiseen ja proosakirjallisuutta tutkivaan osaan. Teoriaosassa mediat ja kirjallisuus sijoitetaan historian ja kirjallisuudenhistorian kontekstiin. Lähtökohtana on kysymys fiktion ja todellisuuden välisestä suhteesta, ja tässä yhteydessä tehdään ero generatiivisen ja klassisen mediaalisuuden välillä. Teoksiin keskittyvässä osassa kirjallisuuden mediaalisuutta tutkitaan kolmen temaattisen aspektin kautta: tarkkaavaisuus, distanssi ja todellisuus, joita tutkitaan aina kahden teoksen avulla. Näiden aspektien välisiä suhteita tarkastellaan sitten seitsemännessä proosateoksessa. Tutkimus osoittaa mediaalisuuden tasojen moninaisuuden aikamme kirjallisuudessa ja auttaa yksittäisten teosten sijoittamisessa kirjallisuuden koko kontekstiin.

Appropriate reactions toward emotional stimuli depend on the distribution of prefrontal attentional resources. In mid-adolescence, prefrontal top-down control systems are less engaged, while subcortical bottom-up emotional systems are more engaged. We used functional magnetic resonance imaging to follow the neural development of attentional distribution, i.e. attending versus ignoring emotional stimuli, in adolescence. 144 healthy adolescents were studied longitudinally at age 14 and 16 while performing a perceptual discrimination task. Participants viewed two pairs of stimuli – one emotional, one abstract – and reported on one pair whether the items were the same or different, while ignoring the other pair. Hence, two experimental conditions were created: 'attending emotion/ignoring abstract' and 'ignoring emotion/attending abstract'. Emotional valence varied between negative, positive, and neutral. Across conditions, reaction times and error rates decreased and activation in the anterior cingulate and inferior frontal gyrus increased from age 14 to 16. In contrast, subcortical regions showed no developmental effect. Activation of the anterior insula increased across ages for attending positive and ignoring negative emotions. Results suggest an ongoing development of prefrontal top-down resources elicited by emotional attention from age 14 to 16 while activity of subcortical regions representing bottom-up processing remains stable.

It is far from conclusive what distinguishes the inattentive (ADD) and the combined (ADHD-C) subtype of ADHD on the neuronal level. Theoretical considerations suggest that especially interval timing processes may dissociate these subtypes from each other. Combining high-density EEG recordings with source localization analyses, we examine whether there are ADHD-subtype specific modulations of neurophysiological processes subserving interval timing in matched groups of ADD (n = 16), ADHD-C (n = 16) and controls (n = 16). Patients with ADD and ADHD-C show deficits in interval timing, which was correlated with the degree of inattention in ADD patients. Compared to healthy controls, patients with ADHD-C display a somewhat weaker, yet consistent response preparation process (contingent negative variation, CNV). In patients with ADD, the early CNV is interrupted, indicating an oscillatory disruption of the interval timing process. This is associated with activations in the supplemental motor areas and the middle frontal gyrus. Patients with ADD display adequate feedback learning mechanisms (feedback-related negativity, FRN), which is not the case in patients with ADHD-C. The results suggest that altered pacemaker-accumulation processes in medial frontal structures distinguish the ADD from the ADHD-C subtype. Particularly in patients with ADD phasic interruptions of preparatory neurophysiological processes are evident, making this a possible diagnostic feature.

Background. Seasonal allergic rhinitis (SAR) is a chronic disease affecting about 23% of the European population with increasing prevalence rates. Beside classical symptoms (i.e. sneezing, nasal congestion), patients frequently complain about subjective impairments in cognitive functioning during periods of acute allergic inflammation. However, objective evidence for such deficits or the role of potential modulators and underlying mechanisms is limited. The present study aimed to investigate the effect of SAR on attention-related cognitive processes. In addition, relationships between attention performance, sleep and mood disturbances as well as specific disease characteristics as potential modulators of this link were explored. Method. SAR patients (n = 41) and non-allergic healthy controls (n = 42) completed a set of attention tasks during a symptomatic allergy period and during a non-symptomatic period. Influences of sleep, mood, total immunoglobulin E (IgE) levels and individual allergy characteristics on cognitive performance were evaluated. Results. Compared to healthy controls, SAR patients had a slower processing speed during both symptomatic and nonsymptomatic allergy periods. Additionally, they showed a more flexible adjustment in attention control, which may serve as a compensatory strategy. Reduction in processing speed was positively associated with total IgE levels whereas flexible adjustment of attention was linked with anxious mood. No association was found between SAR-related attention deficits and allergy characteristics or sleep. Conclusions. SAR represents a state that is crucially linked to impairments in information processing and changes in attentional control adjustments. These cognitive alterations are more likely to be influenced by mood and basal inflammatory processes than sleep impairments or subjective symptom severity.