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Object recognition is such an everyday task it seems almost mundane. We look at the spaces around us and name things seemingly effortlessly. Yet understanding how the process of object recognition unfolds is a great challenge to vision science. Models derived from abstract stimuli have little predictive power for the way people explore "naturalistic" scenes and the objects in them. Naturalistic here refers to unaltered photographs of real scenes. This thesis therefore focusses on the process of recognition of the objects in such naturalistic scenes. People can, for instance, find objects in scenes much more efficiently than models derived from abstract stimuli would predict. To explain this kind of behavior, we describe scenes not solely in terms of physical characteristics (colors, contrasts, lines, orientations, etc.) but by the meaning of the whole scene (kitchen, street, bathroom, etc.) and of the objects within the scene (oven, fire hydrant, soap, etc.). Object recognition now refers to the process of the visual system assigning meaning to the object.
The relationship between objects in a naturalistic scene is far from random. Objects do not typically float in mid-air and cannot take up the same physical space. Moreover, certain scenes typically contain certain objects. A fire hydrant in the kitchen would seem like an anomaly to the average observer. These "rules" can be described as the "grammar" of the scene. Scene grammar is involved in multiple aspects of scene- and object perception. There is, for instance, evidence that overall scene category influences identification of individual objects. Typically, experiments that directly target object recognition do not involve eye movements and studies that involve eye movements are not directly aimed at object recognition, but at gaze allocation. But eye movements are abundant in everyday life, they happen roughly 4 times per second. Here we therefore present two studies that use eye movements to investigate when object recognition takes place while people move their eyes from object to object in a scene. The third study is aimed at the application of novel methods for analyzing data from combined eye movement and neurophysiology (EEG) measurements.
One way to study object perception is to violate the grammar of a scene by placing an object in a scene it does not typically occur in and measuring how long people look at the so-called semantic inconsistency, compared to an object that one would expect in the given scene. Typically, people look at semantic inconsistencies longer and more often, signaling that it requires extra processing. In Study 1 we make use of this behavior to ask whether object recognition still happens when it is not necessary for the task. We designed a search task that made it unnecessary to register object identities. Still, participants looked at the inconsistent objects longer than consistent objects, signaling they did indeed process object and scene identities. Interestingly, the inconsistent objects were not remembered better than the consistent ones. We conclude that object and scene identities (their semantics) are processed in an obligatory fashion; when people are involved in a task that does not require it. In Study 2, we investigate more closely when the first signs of object semantic processing are visible while people make eye movements.
Although the finding that semantic inconsistencies are looked at longer and more often has been replicated often, many of these replications look at gaze duration over a whole trial. The question when during a trial differences between consistencies occur, has yielded mixed results. Some studies only report effects of semantic consistency that accumulate over whole trials, whereas others report influences already on the duration of the very first fixations on inconsistent objects. In study 2 we argue that prior studies reporting first fixation duration may have suffered from methodological shortcomings, such as low trial- and sample sizes, in addition to the use of non-robust statistics and data descriptions. We show that a subset of fixations may be influenced more than others (as is indicated by more skewed fixation duration distributions). Further analyses show that the relationship between the effect of object semantics on fixation durations and its effect on oft replicated cumulative measures is not straightforward (fixation duration distributions do not predict dwell effects) but the effect on both measures may be related in a different way. Possibly, the processing of object meaning unfolds over multiple fixations, only when one fixation does not suffice. However, it would be very valuable to be able to study how processing continues, after a fixation ends.
Study 3 aims to make such a measure possible by combining EEG recordings with eye tracking measurements. Difficulties in analyzing eye tracking–EEG data exist because neural responses vary with different eye movements characteristics. Moreover, fixations follow one another in short succession, causing neural responses to each fixation to overlap in time. These issues make the well-established approach of averaging single trial EEG data into ERPs problematic. As an alternative, we propose the use of multiple regression, explicitly modelling both temporal overlap and eye movement parameters. In Study 3 we show that such a method successfully estimates the influence of covariates it is meant to control for. Moreover, we discuss and explore what additional covariates may be modeled and in what way, in order to obtain confound-free estimates of EEG differences between conditions. One important finding is that stimulus properties of physically variable stimuli such as complex scenes, can influence EEG signals and deserve close consideration during experimental design or modelling efforts. Overall, the method compares favorably to averaging methods.
From the studies in this thesis, we directly learn that object recognition is a process that happens in an obligatory fashion, when the task does not require it. We also learn that only a subset of first fixations to objects are affected by the processing of object meaning and its fit to its surroundings. Comparison between first fixation and first dwell effects suggest that, in active vision, object semantics processing sometimes unfolds over multiple fixations. And finally, we learn that regression-based methods for combined eye tracking-EEG analysis provide a plausible way forward for investigating how object recognition unfolds in active vision.
Expression, perception and recognition of intense emotions in healthy and depressed individuals
(2017)
Die Fähigkeit die Gefühle anderer zu erkennen und einzuordnen ermöglicht es soziale Situationen richtig einzuschätzen und soziale Beziehungen aufzubauen. Da Emotionen also in unserem Leben eine wichtige Rolle spielen, kann eine Dysregulation der Emotionsverarbeitung auch zu elementaren Einschränkungen führen. Menschen, die unter depressiven Episoden leiden, durchleben beispielsweise regelmäßig Phasen intensiver und anhaltender Traurigkeit. Jedoch ist noch nicht vollständig erklärt, wie es zu dieser verzerrten Emotionswahrnehmung kommt. Diese Dissertation hatte deshalb das Ziel, den Ausdruck, die Wahrnehmung und das Erkennen extremer Emotionen genauer zu beleuchten.
In Studie 1 wurden der Ausdruck und das Erkennen extremer Emotionen untersucht.
Hierbei dienten aus dem Internet bezogene Videosequenzen von Kindern und Erwachsenen als Basis, in denen diese sich in Situationen befanden, die sie extrem negative oder extrem positive Emotionen durchleben ließen. Die Gesichtsausdrücke der Kinder und Erwachsenen wurden dann zum Zeitpunkt der stärksten emotionalen Erregung in ein Bild umgewandelt und von unabhängigen Ratern auf ihre Valenz und ihr Arousal eingeschätzt. Es wurde beobachtet, dass - entgegen der Vorhersage etablierter Emotionstheorien (z.B. Ekman, 1993) – Emotionen hoher positiver und negativer Intensität schwer auseinander zu halten sind. Tatsächlich wurden positive Emotionsausdrücke häufig als negativ eingeschätzt. Eine mögliche Erklärung dafür liefern Aragón und Kollegen (2015). Sie schätzen den Ausdruck negativer Emotionen in positiven Situationen als Emotionsregulationsstrategie ein, die dazu dient ein emotionales Equilibrium wieder herzustellen, das durch die überwältigenden positiven Emotionen aus dem Gleichgewicht gebracht wurde.
In Studie 2 und 3 wurde die Wahrnehmung negativer Emotionen bei depressiven Menschen im Vergleich zu gesunden Kontrollprobanden auf subjektiver und physiologischer Ebene untersucht. Hierbei wurde zunächst im Rahmen von Studie 2 untersucht, ob Parameter des autonomen Nervensystems (ANS) sich zwischen depressiven und gesunden Probanden unterscheiden. ANS-Parameter umfassten Hormone (Cortisol und DHEA), Herzratenvariabilität (HRV), Hautleitfähigkeit (GSR), Hauttemperatur (TEMP) und Atemfrequenz (RSP). Es konnten erhöhte DHEA-Werte, eine erhöhte Hauttemperatur und eine reduzierte Atemfrequenz in der Patientengruppe gefunden werden. Eine erhöhte Hauttemperatur korrelierte zudem mit der Ausprägung depressiver Symptome und der aktuellen Stimmung. Reduzierte HRV-Werte wurden hauptsächlich auf antidepressive Medikation zurückgeführt.
In Studie 3 wurde dann die Reaktion der Probanden auf emotionsevozierende Stimuli verschiedener Valenzkategorien (neutral, leicht negative, hoch negative) untersucht. Hierbei wurden sowohl physiologische Parameter (TEMP, HRV, GSR, RSP) als auch die subjektive Einschätzung der Stimuli bezüglich ihrer Valenz und ihres Arousal erhoben. Die Befunde bezüglich Hauttemperatur und HRV-Werte aus Studie 2 konnten in Studie 3 repliziert
werden. Zudem zeigte sich eine akzentuierte Reaktion der RSP sowie höhere Valenz- und Arousalratings in der Patientengruppe. Das subjektiv intensivere Empfinden der Stimuli bei den Patienten hing zusätzlich mit emotionaler und sozialer Kompetenz zusammen.
In dieser Dissertation konnte gezeigt werden, dass Ausdrücke intensiver Emotionen im Gesicht oft als zweideutig wahrgenommen werden. Um ein genaueres Verständnis der Emotionswahrnehmung bei depressiven Menschen zu erlangen, konnten zudem mehrere Parameter des ANS identifiziert werden, die teils noch nicht untersucht wurden und einer intensiveren Emotionswahrnehmung bei depressiven Patienten zugrunde liegen könnten.
Hierbei wurden zusätzlich Zusammenhänge zu weiteren Aspekten der Depression, wie Defiziten in sozialen Kompetenzen, aufgezeigt. Damit gibt diese Dissertation umfassende Aufschlüsse über Emotionsverarbeitungsprozesse bei gesunden und depressiven Menschen.
Faces are thought to be processed primarily according to their configurations which is in-ferred from comparisons with non-facial stimuli. While the whole (face) seems to be more than the sum of its parts, the same does not apply to objects which are processed analytically according to their featural information. A recent recognition model stresses the importance of certain visual information within facial stimuli. By applying a specific filtering technique, stimuli can be generated that are restricted to contain information of only a certain orienta-tion. Dakin and Watt (2009) reported greatest recognition performance with faces that only contained horizontally aligned information with accuracy continuously declining at vertical. Furthermore, they showed that, compared with images of natural scenes, horizontal contours within faces have an unusual tendency to fall into vertically co-aligned clusters which were labelled biological ‘bar code’ referring to a highly constrained one-dimensional code. Con-secutive research tested for face-specific processing by comparing faces and objects that displayed information of different orientations. Results suggested configural processing only for faces that contained horizontal information (Goffaux & Dakin, 2010). The findings con-tribute important insight on a still unanswered question in face processing research: what information is extracted from faces for recognizing them. Despite the importance of remembering human faces on a daily basis, this ability seems to develop disadvantageously over lifetime. Decreased accuracy cannot be attributed to de-creased general cognitive ability (Hildebrandt, Wilhelm, Schmiedek, Herzmann, & Sommer, 2011) and slower reactions times are assumed to be a product of decision making rather than sensory speed (Habak, Wilkinson, & Wilson, 2008). Considering the amount of published work on face recognition, there is a lack of studies available assessing this important ability at a higher age. New theoretical concepts are rarely examined with older participants, appar-ently assuming their general validity. The current dissertation tries to help fill this gap by assessing the importance of horizontal information from a developmental perspective com-paring younger and older adults under different experimental variations. The first study showed, that presenting older participants with horizontally filtered faces has a dispropor-tional negative impact on recognizing younger unfamiliar faces suggesting differential pro-cessing mechanisms, since recognizing stimuli that only contained vertical information did not differ between age groups. On this basis, the following study manipulated the presented stimulus material, since some evidence suggests that own-age faces are more easily recog-nized compared to faces of other ages, which is referred to as “own-age bias”. Therefore, the second study systematically assessed the impact of stimulus age on recognition sensitivity. Moreover, encoding modalities were varied by providing increased exposure duration to the stimuli. The results of the first study were replicated, as older participants’ performance was still poor at recognizing younger faces, independent from encoding modalities. However, similar face recognition sensitivity compared to younger adults was observable when filtered faces of the older adults’ own age had to be recognized. Interestingly, correlations between recognizing filtered and unfiltered faces were obtained for younger adults but not for older adults suggesting age variant processing of horizontal information. The last study assessed the importance of horizontal information with stimulus material familiar to the observer. Although research highlights differences between recognizing unfamiliar and familiar stimu-lus material, this factor is often not considered by contemporary research. By presenting par-ticipants with their own faces, a stimulus of greatest individual familiarity was chosen. The superiority of own face recognition over other familiar material is referred to as “self-face advantage” and has been shown in comparison with personally familiar faces (Keyes & Brady, 2010) and famous faces (Caharel et al., 2002). While younger adults indeed recog-nized their self-faces better compared to famous faces independent from stimuli being fil-tered or unfiltered, older participants displayed a completely different pattern including the inability to recognize their filtered self-faces. Again, significant associations were obtained between filtered and unfiltered recognition conditions suggesting convergent processing mechanisms for younger adults but not for the older age group. This dissertation provides a first insight in the divergence of response behavior in older adults with a recent face processing model. While the obtained data undermine the im-portance of horizontal information in younger adults by replicating and extending previously published work, a profoundly different type of processing is suggested at a higher age which largely relies on low-level pictorial information due to the inability to process horizontally filtered faces configurally. Specifically, it is suggested that with age, focusing on aging-salient features with configural processing disrupted may function as a critical source of di-agnostic information which can ultimately result in performance similar to younger adults.
From an early understanding of organisational theorist (Bartlett & Ghosal, 1989; 1990), the function of global teams in transnational organisations has been conceptualised as the transformation of different embedded cultural practices for the development of a global strategy, products and services. Simultaneously, in the field, from the beginning of the 1990ies to the edge of the new millennium neo-liberal political developments enforced a free flow of capital on a global level (cf. Turner, 2006). In line with the development of respective connectivity via the internet the form of globally distributed team work was spread (Maznevski & Chudoba, 2000). In a study by Biggs (2000), published just after the millennial change, it was shown that 60% of tasks in multinational companies are accomplished by virtual teams. More recent data (Society for Human Resource Management, 2012) showed that the prevalence of such teams stayed more or less constant in the last 10 years. According to the survey 66% of companies are working with distributed global teams.
Globally distributed teams were already described by Bartlett and Ghosal (1989) in their functions of articulation and translation of differing market practices for the integration of requirements and needs on a global level. From a European perspective the importance to further develop innovation capabilities in order to compete in the global market is stressed today (Imp3rove, 2012). In a globalised economy not only the big multinational companies are involved in globally distributed research and development activities (R&D). On the level SMEs, for example, in Switzerland the involvement in global development processes is increasing (Gassmann, 2009). From my own experiences in working with Swiss SMEs, the macro-economic processes in regard to the strong Swiss Franc may accelerate such processes. Thus, the form of globally distributed teams, and their functional task in global development processes, can be viewed as highly relevant, in a globalised economy.
The crucial question for companies at the moment is, if teams can be enabled for innovative project work, which enables the integration of diverging perspectives in a globally distributed setting? Or, if such teams have to be collocated for more innovative, interdependent task work? Requirements for integrating embedded knowledge from different regionally defined clusters into global innovations at least, seems to indicate for the relevance of interdependent globally distributed team work (cf. Li, Eden, Hitt, Ireland, & Garrett, 2012). Bilateral practices of partnering, for example in the Swiss pharmaceutical sector, lead to the integration of selected subsidiaries in the R&D process of the company (Festel et al., 2010). Thus, the form of dispersion for project teams becomes more critical for effective global R&D practices (Boyer O’Leary & Cummings, 2007). So called partially distributed teams integrating balanced subgroups between two sites, hence, become an important subject of inquiry with practical relevance.
The context of partially distributed team work represents by virtue a context involving multiple perspectives influenced by the involvement of actors stemming from different cultural contexts (Dekker, Rutte, & Van den Berg, 2008). It thereby provides the synergetic potential for integrating different perspectives in the resolution of complex problems on a global level (Janssens & Brett, 2006). Simultaneously, cultural diversity engenders challenges for collaboration. Challenges, like different understandings and interpretations regarding tasks, the structuring of communication (Maznevski & Chudoba, 2000) and unexpected events occurring in the collaboration between the actors (Dekker et al., 2008; Oertel & Antoni, 2014) were identified in respective empirical studies.
Opportunities and challenges of partially distributed global teams can be compared with the problematic of face-to-face (f2f) teams with a moderate amount of diversity. Studies have shown (see Thatcher & Patel, 2011 for a meta-analysis) that when the distribution of diversity characteristics is aligned to potentially form culture specific subgroups, so-called diversity faultlines (Lau & Murnighan, 1998), negative subgroup dynamics are reinforced.
To achieve the above mentioned synergetic potentials it seems important to effectively cope with such negative dynamics and allow for a balanced participation in partially distributed teams (Janssens & Brett, 2006). In the research on faultline teams, especially the structuring of task-related interdependences across respective subgroups has been identified as an important impediment for the mentioned subgroup dynamics. Task interdependences, which cross functional roles across respective group faultlines (Bettencourt, Molix, Talley, & Eubanks, 2007; Marcus-Newhall, Miller, Holtz, & Brewer, 1993), are able to unlock the inherent potentials of globally distributed teams on more complex tasks that require the integration of different perspectives. From a work group diversity perspective (van Knippenberg & Schippers, 2007), partially distributed global teams represent a research object for studying the interaction between social categorisation processes involved in the above mentioned subgroup dynamics, and processes of task-related information processing required for innovative team outputs. The exploration of effects of task structures on the interaction between categorisation processes and task-related information processing (van Knippenberg et al., 2004), will be in the main explorative research focus of this thesis. The research thesis represents a heuristic explorative inquiry (Kleining & Witt, 2001) of respective dynamics and structural as well as process-related enablers.
The thesis starts with the theoretical part, in which the historical development of the understanding of teams as open, complex and temporally dynamic systems (Arrow et al., 2005, 2000), will be outlined. A sound definition of partially distributed global teams, including the respective contextual characteristics will be delineated. In a sensitizing framework (Blumer, 1954) which guided the explorative research process, the central boundary condition of task interdependence (Wageman, 2001) and respective episodic theories for explaining global task-related dynamics in teams (Marks et al., 2001), the dynamics of social categorisation (Gaertner, Dovidio, Anastasio, Bachman, & Rust, 1993; Gaertner & Dovidio, 2000), as well as the interaction between social categorisation processes and task-related information processing will be integrated (van Knippenberg et al., 2004). According to the framework, empirical studies on effects of task interdependence on interactions between task-related information processing and social categorisation processes will be addressed (van Knippenberg et al., 2004).
The empirical part of the contribution will be split in two parts. In the first heuristic exploratory study eleven partially distributed global teams are followed up during the time of relevant innovation projects. The approach allowed the study of task interdependence, productive interactions with social categorisation processes and there effects on team innovation. In the second empirical step, the developed hypotheses, were tested in an experimental simulation (Arrow et al., 2005, 2000) in undergraduate courses.
As a conclusion of the two exploratory studies, an episodic team process model will be outlined. The model specifies interdependence dynamics, which allows for team innovation. Furthermore, on a process level, the episodic categorisation-elaboration model (van Knippenberg et al., 2004) proposes three critical team performance episodes. Dynamics in the interplay between task-related information processing and social categorisation processes allow for the development of hypothesis for further research projects. Finally the implications for theory and the practical relevance of the heuristic model will be discussed.
Die Dissertation befasst sich mit den kognitiven Prozessen die Intelligenz ausmachen und ist in drei Teile aufgeteilt. Der erste Teil rezensiert den Beitrag kognitiver und nicht-kognitiver Variablen zur Vorhersage von Hochbegabung in einer Altersspanne die von der Geburt bis zur Einschulung reicht. Aus dem nicht-kognitiven Bereich stammen Konstrukte wie Schlafverhalten, motivationale Faktoren wie Neugier und Interesse, und deren Interaktion mit dem sozialen Umfeld. Kognitive Variablen stellen frühe, außergewöhnliche Sprach-, Lese-, Schreib- und Rechenfähigkeiten dar, sowie Intelligenzquotienten, die mit den gängigsten testpsychologischen Verfahren ermittelt werden, und Komponenten der Informationsverarbeitung wie Habituation und Arbeitsgedächtnis. Trotz der Berichte über mittlere Korrelation ist die aktuelle Datenlage kritisch zu betrachten und weist eine niedrige Vorhersagevalidität der Frühprognose von Hochbegabung auf. Es wird mit dem dynamischen Modell der Intelligenz argumentiert, nach dem die mangelnde prognostische Validität und die Unzuverlässigkeit der kognitiven Vorhersageindikatoren auf die Annahme zurückzuführen sind, dass kognitive Prozesse unabhängig voneinander sind. Erst im Laufe des Lebens werden diese immer häufiger miteinander verknüpft und korreliert (Mutualismus). Das bedeutet, es findet eine zunehmende Integration kognitiver Prozesse statt und daraus resultiert der g-Faktor.
Doch das Arbeitsgedächtnis spielt weiterhin eine zentrale Rolle in Bezug auf Intelligenz, wenn nicht im Säuglingsalter, dann zumindest ab dem Vorschulalter und besonders im Erwachsenenalter. Arbeitsgedächtniskapazität stellt das Ausmaß an Fähigkeit dar, Informationen simultan zu speichern und zu verarbeiten, ohne die Notwendigkeit auf Vorwissen zurückzugreifen. Es kann damit als eng umschriebener kognitiver Prozess aufgefasst werden. Vorherige Forschungsarbeiten haben bereits deutlich gezeigt, dass Arbeitsgedächtnis und Intelligenz korrelativ stark zusammenhängen. Das ist durchaus überraschend, denn die Aufgaben und Tests mit denen die Konstrukte jeweils erfasst werden können sich oberflächlich stark unterscheiden. Um fluide Intelligenz valide erfassen zu können, sind Aufgaben zum induktiven Denken, wie zum Beispiel Matrix-Aufgaben, sehr beliebt. Im Rahmen der zweiten Arbeit hat man sich dem Einfluss der Prozesse Zielmanagement und Regel-Induktion auf den Zusammenhang zwischen Arbeitsgedächtnis und Problemlösung der Matrix-Aufgaben gewidmet. Zielmanagement wurde bereits zuvor mit dem Arbeitsgedächtnis in Verbindung gebracht jedoch war die Befundlage hinsichtlich der Regel-Induktion unklar. Daher sollte die Hypothese ob Regel-Induktion unabhängig vom Arbeitsgedächtnis ist, in einem kritischen Experiment überprüft werden. Bei Neutralisierung der Notwendigkeit für Regelinduktion, indem den Probanden die Regeln im Voraus erklärt wurden, konnte man einen erhöhten Zusammenhang zwischen dem Arbeitsgedächtnis und der Leistung in der Matrix-Aufgabe erkennen. Das deutete in der Tat darauf hin, dass Regel-Induktion nicht vom Arbeitsgedächtnis abhängig ist, zumindest nicht im gleichen Maße wie Zielmanagement. Darüber hinaus zeigte sich: Die Kenntnis der Regeln beeinflusst den Problemlöseprozess. Eye-Tracking-Messungen weisen auf eine konstruktive Anpassungsstrategie in der Experimentalbedingung (mit Regelwissen) hin. Basierend auf den Erkenntnissen aus vier Experimenten, wird mit zwei möglichen Mechanismen argumentiert, die die Steigerung des Zusammenhangs zwischen Arbeitsgedächtnis und Matrix-Problemlösen in der Experimentalgruppe erklären könnten.
Alternativ zur zuvor angenommenen Unabhängigkeit von Regel-Induktion und Arbeitsgedächtnis, könnte die erhöhte Korrelation bei bekannten Regeln auch mit der beobachteten Strategieänderung erklärbar sein. Die dritte und letzte Arbeit widmete sich deshalb erneut dieser Fragestellung. Erneut kamen Matrix-Aufgaben zum Einsatz und es wurden Testleistung, Augenbewegung und Reaktionszeiten erhoben, um den Einfluss von Regelwissen zu erfassen. Es zeigte sich die Anwendung einer effektiveren Lösungsstrategie in der Experimentalbedingung. Anhand der Eye-Tracking Messung wurde gezeigt, dass Probanden mit Regelwissen über einen längeren Zeitraum das problemrelevante Areal der Matrix-Aufgabe fixieren, und eine niedrigere Frequenz an Sakkaden zwischen diesem Areal und den Antwortalternativen aufwiesen.
Weitere Einflussvariablen auf die Lösestrategie stellen Schwierigkeit der Aufgabe und Fähigkeiten des Probanden dar. Diese weisen einen differenziellen Einfluss auf zwei Subgruppen von Indikatoren der Augenbewegungsmessung auf, die in Relation zu den Reaktionszeiten gesetzt wurden um ein besseres Verständnis dieser Variablen zu erzielen. Es wird vermutet, dass Variablen wie Augenbewegungen und Reaktionszeiten das Ausmaß des Entstehens von mentalen Modellen während des logischen Denkens widerspiegeln. Unter der Annahme dass die Komplexität von Mentalen Modellen mit einer gewissen Belastung für das Arbeitsgedächtnis einhergeht, lassen sich auch vorherige Ergebnisse mit dieser Hypothese in Einklang bringen. Abschließend werden die grundlegenden kognitiven Prozesse des induktiven Denkens diskutiert und ein Ausblick auf zukünftige Intelligenzmessung angeboten.
Eye-Tracking bezeichnet das Messen und Aufzeichnen der Blickbewegungen einer Person. Historisch gesehen basiert Eye-Tracking auf Beobachtungen des Testleiters, der das Blickverhalten der Probanden während des Versuchsablaufes oder die Videoaufzeichnung des Blickverhaltens eines Probanden in einer Testsituation kodierte. Dabei konnte allerdings nur die Blickrichtung des Probanden erhoben werden. Heutzutage ist es jedoch möglich, aufgrund neuerer, automatisierter Eye-Tracking-Techniken detailliertere Blickbewegungen, wie z.B. Fixationen und Sakkaden, zu messen. Diese Verbesserung der Eye-Tracking-Technik ermöglicht nicht nur passives Eye-Tracking, sondern auch aktives Blickkontingenz-Eye-Tracking. Passives Eye-Tracking bezeichnet das Messen und Aufzeichnen des Blickverhaltens, um herauszufinden, wo der Proband hinschaut. Im Gegensatz dazu erhebt das aktive Blickkontingenz-Eye-Tracking nicht nur, wo ein Proband hinschaut, sondern ermöglicht dem Probanden auch, die Stimuli, die auf einem Bildschirm präsentiert werden, aktiv zu verändern oder zu kontrollieren. Dabei wird das Blickverhalten online kodiert, und spezifisches Blickverhalten ist an eine kontingente Veränderung der Stimuli auf dem Bildschirm gekoppelt. Deshalb kann das aktive Blickkontingenz-Eye-Tracking eingesetzt werden, um den Probanden aktive Kontrolle über ihre visuelle Umwelt zu ermöglichen.
In der psychologischen Forschung ist Eye-Tracking ein wichtiges Forschungs-instrument, da das Blickverhalten in spezifischen Eye-Tracking-Aufgaben genutzt werden kann, um Aufschluss über kognitive Prozesse, wie z.B. Aufmerksamkeit, Lernen und Gedächtnis, zu gewinnen. Unterschiedliche passive und aktiv-blickkontingente Eye-Tracking- Aufgaben wurden entwickelt, um eine Vielzahl an kognitiven Prozessen im Erwachsenen- und Säuglingsalter zu untersuchen. Diese Aufgaben sind besonders wichtig in der Säuglingsforschung, da es in diesem Alter schwierig ist, kognitive Prozesse zu untersuchen. Dies hängt damit zusammen, dass es sich um eine präverbale Stichprobe, die nur über ein limitiertes motorisches Repertoire verfügt, handelt. Obwohl kognitive Prozesse von Erwachsenen anhand verbaler oder anderer motorischer Aufgaben untersucht werden können, werden passive und aktiv-blickkontingente Eye-Tracking-Aufgaben regelmäßig in dieser Altersgruppe eingesetzt, da sie zusätzliche Informationen über kognitive Prozesse liefern können. Neben der Möglichkeit zur Untersuchung von kognitiven Prozessen bieten aktiv-blickkontingente Eye-Tracking-Aufgaben den Probanden auch die Gelegenheit, ihre visuelle Umwelt aktiv zu kontrollieren. Dennoch werden aktiv-blickkontingente Eye-Tracking- Aufgaben nur selten eingesetzt, um Probanden visuelle Kontrolle über ihre Umwelt zu verschaffen.
Bis jetzt wurden aktiv-blickkontingente Eye-Tracking-Aufgaben zur Kontrolle der visuellen Umwelt nur bei Erwachsenen, aber noch nicht bei Säuglingen eingesetzt. Da diese Aufgaben jedoch auch für Säuglinge und Kleinkinder geeignet sind, besteht die Möglichkeit, diese Methode über die gesamte Lebenspanne hinweg anzuwenden. Somit kann das Erlernen des Kontrollierens der Umwelt durch Blickverhalten über die gesamte Lebensspanne untersucht werden.
Die vorliegende Dissertation hat sich genau dies zum Ziel gesetzt. Um dieses Ziel zu erreichen, wurde eine neue aktiv-blickkontingente Eye-Tracking-Aufgabe entwickelt, die sogenannte gaze-contingent learning task (GCLT). Im Wesentlichen ist die GCLT eine operante Konditionierungsaufgabe, bei der sich Probanden Kontrolle über ihre visuelle Umwelt aneignen, indem sie eine bestimmte blickkontingente Assoziation zwischen ihrem Blickverhalten und einem visuellen Effekt erlernen. Die in dieser Dissertation verwendete GCLT umfasst zwei Hauptversionen: zum einen die sog. one disc GCLT, und zum anderen die two discs GCLT. In der one disc GCLT wird ein Kreis auf der rechten Bildschirmseite gezeigt. Jedes Mal, wenn der Proband auf diesen Kreis schaut, erscheint ein Stimulus auf der linken Bildschirmseite. Somit kommt dem Kreis eine Schalterfunktion zu. In der two discs GCLT ist sowohl am rechten als auch am linken Bildschirmrand ein Kreis zu sehen. Hier kommt nur jeweils einem der beiden Kreise die Schalterfunktion zu. Um ihre visuelle Umwelt zu kontrollieren, müssen Probanden innerhalb der one disc GCLT die blickkontingente Assoziation zwischen ihren Blicken auf den Kreis und dem Erscheinen eines Stimulus erlernen, während sie in der two discs GCLT außerdem noch lernen müssen, zwischen dem Kreis mit und dem Kreis ohne Schalterfunktion zu unterscheiden.
In the present work, mismatch negativity (MMN) was used to examine the contribution of spectral vs. temporal perceptual features to vowel length discrimination in children and adults. Three age groups (adults vs. 9-10 years vs. 10-11 years olds) have been taken to examine developmental effects on vowel length perception. Natural (i.e., spectrotemporal) vowel length differences were compared with (artificially modified) stimulus pairs varying only in temporal or spectral characteristics to contrast spectral, temporal and spectrotemporal processing.
The result indicates that, while adults integrate spectral and temporal aspects of the speech signal in an additive way, children of 9-10 years of age sequentially process both features. However, vowel length processing is found to become adultlike at the age of 10-11 years.
Different types of altruistic behavior, namely help-giving, altruistic punishment, and moral courage, are identifiable and distinguishable in the literature, but little is known how they relate to each other. This is significant because understanding altruism and other-regarding behavior is important in the attempt to solve global problems of overpopulation and depletion of natural resources. Understanding the helping forms of altruism (help-giving and sharing) can be helpful, for example, when designing donation collections or recruiting volunteers. Understanding the punitive forms of altruism (moral courage and altruistic punishment) gives valuable insight on individuals participating in campaigns where there is a need to take action, for example, against polluters or governments that violate human rights. The empirical evidence presented in this dissertation demonstrate individual and cultural differences in help-giving, altruistic punishment, and morally courageous behavior. The willingness to engage in the three types of altruistic behaviors relate differently to subjectively preferred thinking style and to personality traits, both in real-life and on the Internet. The divergencies are observable between Eastern (Indian) and Western (German) cultures, where the overlap of oneself and other individuals is experienced in different levels.
Imitation paradigms are used in various domains of developmental psychological research to assess various cognitive processes such as memory (deferred imitation), action perception and action understanding (mainly direct imitation), as well as categorization and learning about objects (deferred imitation with a change in target objects and generalized imitation). Although these processes are most likely not independent from each other, their relations are still largely unclear. On the one hand, deferred imitation studies have shown that infants' performance improves with increasing age, resulting in the reproduction of more target actions after longer delay intervals. On the other hand, imitation studies focusing on infants' action understanding have found that infants do not necessarily imitate the model's exact actions – actions or action steps that seem to be irrational or irrelevant are omitted by infants under certain circumstances (selective imitation). Additionally, findings of imitation studies that require a transfer of the target actions to novel objects have demonstrated that infants do not only learn about actions, but also about objects, when they engage in imitation.
The present dissertation aims at integrating different perspectives of imitation research by testing 12- and 18-month-old infants in deferred imitation tests consisting of functional vs. arbitrary target actions, and by combining deferred imitation with eye tracking in half of the experiments. A deferred imitation paradigm was chosen to assess memory performance. Systematic variation of target action characteristics enabled the assessment of infants' imitation pattern, i.e., if they would imitate one kind of target actions more frequently than the other. Functionality was chosen as the action characteristic in focus because function is an object's most important property, thus this variation might shed some light on infants' learning about objects in the context of an imitation test. The main goal of the eye tracking experiments was to tackle the relations between infants' visual attention to, and deferred imitation of, different kinds of target actions.
The behavioral experiments revealed that both 12- and 18-month-olds imitated significantly more functional than arbitrary target actions after a delay of 30 minutes. In addition, while 12-month-olds showed a memory effect only for functional actions, 18-month-olds showed a memory effect for both kinds of actions. Thus, 12-month-olds imitated strictly selectively, and 18-month-olds imitated more exactly. This shows that the well established memory effect is modulated by target action functionality, which affects 12- and 18-month-olds' imitation differently. Furthermore, when retested after a two weeks delay, 18-month-olds' performance rates of functional and arbitrary target actions decreased parallel. This suggests that selective imitation is not affected by the duration of the retention interval, and that selection of target actions takes place at an earlier stage of action perception and memory processes.
In the eye tracking experiments, both 12- and 18-month-olds' imitation patterns replicated the findings of the behavioral experiments, showing consistently higher imitation rates of functional than arbitrary target actions. Contrary to this, infants' fixation times to the target actions were not affected by target action functionality. This contrast was supported by statistical analyses that found no clear correspondence between visual attention to and deferred imitation of target actions. This suggests that selective imitation cannot be explained by selective visual attention. Nevertheless, finer-grained analyses of gaze and imitation data in the 18 months old group suggested that infants' increased attention to the social-communicative context of the imitation task was related to more exact imitation, i.e. imitation of not only functional, but also arbitrary target actions.
The findings are discussed against the background of imitation theories, with regard to the relations between different cognitive processes underlying infants' imitation, such as memory, action perception and learning about objects.
The term compensation is widely used in every-day language, in psychological research, and also discussed in the context of Attention Deficit Hyperactivity Disorder (ADHD). However, few studies have looked at psychological compensation in ADHD systematically and theory based. Compensation can be inferred if a deficit (i.e., a mismatch between skill and environmental demand) is counterbalanced by the investment of more effort, the utilization of latent or the acquisition of new skills. Based on the application of a theoretical framework (Bäckman & Dixon, 1992) to ADHD, I developed the following aims: (1) To reassess the awareness of deficits in ADHD and (2) to explore psychological compensation in a group with ADHD that accomplishes high achievement.
The results of Study 1 showed that children with ADHD did not overestimate their own skills compared to a group matched for academic achievement. In Study 2, college students with ADHD reported higher achievement motivation compared to college students without ADHD. Furthermore, results indicated that women with ADHD compensate by adopting compensatory effort and obsessive-compulsive behavior. Study 3 showed that female college students compensate for possible deficits in solving a flanker task by being overly cautious, which may reflect more obsessive-compulsive behavior.
The studies are discussed within the framework of psychological compensation. They add to the understanding of compensation in ADHD by (1) the reassessment of awareness of deficits in ADHD by including a group without ADHD but with low achievement, and by (2) suggesting that overly cautious behavior could be a form of psychological compensation in females with ADHD enabling them to enter college, leading to a late diagnosis and to good performance in cognitive tasks (i.e., flanker task).
Limitations are, that I did not test all components of the theoretical framework in one study and that I did not include adults with ADHD that did not enter college in Study 2 and 3 to test if achievement motivation or overly cautious behavior explains why some adults with ADHD gain admittance to higher education and show good performance in cognitive tasks and others do not.