Perceptual grouping is an integral part of visual object recognition. It organizes elements within our visual field according to a set of heuristics (grouping principles), most of which are not well understood. To identify their temporal processing dynamics (i.e., to identify whether they rely on neuronal feedforward or recurrent activation), we introduce the primed flanker task that is based on a firm empirical and theoretical background. In three sets of experiments, participants responded to visual stimuli that were either grouped by (1) similarity of brightness, shape, or size, (2) symmetry and closure, or (3) Good Gestalt. We investigated whether these grouping cues were effective in rapid visuomotor processing (i.e., in terms of response times, error rates, and priming effects) and whether the results met theory-driven indicators of feedforward processing. (1) In the first set of experiments with similarity cues, we varied subjective grouping strength and found that stronger grouping in the targets enhanced overall response times while stronger grouping in the primes enhanced priming effects in motor responses. We also obtained differences between rapid visuomotor processing and the subjective impression with cues of brightness and shape but not with cues of brightness and size. These results show that the primed flanker task is an objective measure for comparing different feedforward-transmitted groupings. (2) In the second set of experiments, we used the task to study grouping by symmetry and grouping by closure that are more complex than similarity cues. We obtained results that were mostly in accordance with a feedforward model. Some other factors (line of view, orientation of the symmetry axis) were irrelevant for processing of symmetry cues. Thus, these experiments suggest that closure and (possibly) viewpoint-independent symmetry cues are extracted rapidly during the first feedforward wave of neuronal processing. (3) In the third set of experiments, we used the task to study grouping by Good Gestalt (i.e., visual completion in occluded shapes). By varying the amount of occlusion, we found that the processing was in accordance with a feedforward model only when occlusion was very limited. Thus, these experiments suggest that Good Gestalt is not extracted rapidly during the first feedforward wave of neuronal processing but relies on recurrent activation. I conclude (1) that the primed flanker task is an excellent tool to identify and compare the processing characteristics of different grouping cues by behavioral means, (2) that grouping strength and other factors are strongly modulating these processing characteristics, which (3) challenges a dichotomous classification of grouping cues based on feedforward vs. recurrent processing (incremental grouping theory, Roelfsema, 2006), and (4) that a focus on temporal processing dynamics is necessary to understand perceptual grouping.
When stimulus and response overlap in a choice-reaction task, enhanced performance can be observed. This effect, the so-called Stimulus-Response Compatibility (SRC) has been shown to appear for a variety of different stimulus features such as numerical or physical size, luminance, or pitch height. While many of these SRC effects have been investigated in an isolated manner, only fewer studies focus on possible interferences when more than one stimulus dimension is varied. The present thesis investigated how the SRC effect of pitch heights, the so-called SPARC effect (Spatial Pitch Associations of Response Codes), is influenced by additionally varied stimulus information. In Study 1, the pitch heights of presented tones were varied along with timbre categories under two different task and pitch range conditions and with two different response alignments. Similarly, in Study 2, pitch heights as well as numerical values were varied within sung numbers under two different task conditions. The results showed simultaneous SRC effects appearing independently of each other in both studies: In Study 1, an expected SRC effect of pitch heights with horizontal responses (i.e., a horizontal SPARC effect) was observed. More interestingly, an additional and unexpected SRC effect of timbre with response sides presented itself independently of this SPARC effect. Similar results were obtained in Study 2: Here, an SRC effect for pitch heights (SPARC) and an SRC effect for numbers (i.e., SNARC or Spatial Numerical Associations of Response Codes, respectively) were observed and again the effects did not interfere with each other. Thus, results indicate that SPARC with horizontal responses does not interfere with SRC effects of other, simultaneously varied stimulus dimensions. These findings are discussed within the principle of polarity correspondence and the dimensional overlap model as theoretical accounts for SRC effects. In sum, it appears that the different types of information according to varied stimulus dimensions enter the decision stage of stimulus processing from separate channels.
According to the domain specific models of speech perception, speech is supposed to be processed distinctively compared to non-speech. This assumption is supported by many studies dealing with the processing of speech and non-speech stimuli. However, the complexity of both stimulus classes is not matched in most studies, which might be a confounding factor, according to the cue specific models of speech perception. One solution is spectrally rotated speech, which has already been used in a range of fMRI and PET studies. In order to be able to investigate the role of stimulus complexity, vowels, spectrally rotated vowels and a second non-speech condition with two bands of sinusoidal waves, representing the first two formants of the vowels, were used in the present thesis. A detailed description of the creation and the properties of the whole stimulus set are given in Chapter 2 (Experiment 1) of this work. These stimuli were used to investigate the auditory processing of speech and non-speech sounds in a group of dyslexic adults and age matched controls (Experiment 2). The results support the assumption of a general auditory deficit in dyslexia. In order to compare the sensory processing of speech and non-speech in healthy adults on the electrophysiological level, stimuli were also presented within a multifeature oddball paradigm (Experiment 3). Vowels evoked a larger mismatch negativity (MMN) compared to both non-speech stimulus types. The MMN evoked by tones and spectrally rotated tones were compared in Experiment 4, to investigate the role of harmony. No difference in the area of MMN was found, indicating that the results found in Experiment 3 were not moderated by the harmonic structure of the vowels. All results are discussed in the context of the domain and cue specific models of speech perception.
From an evolutionary point of view, it can be assumed that visual processing and rapid detection of potentially dangerous stimuli in the environment (e.g., perilous animals) is highly adaptive for all humans. In the present dissertation, I address three research questions; (1) Is information processing of threatening stimuli enhanced in individuals with specific phobias? (2) Are there any differences between the different types of phobia (e.g., spider phobia vs. snake phobia)? (3) Is the frequently reported attentional bias of individuals with specific phobias - which may contribute to an enhancement in information processing – also detectable in a prior entry paradigm? In Experiments 1 to 3 of the present thesis non-anxious control, spider-fearful, snake-fearful, and blood-injection-injury-fearful participants took part in the study. We applied in each experiment a response priming paradigm which has a strong theoretical (cf. rapid-chase theory; Schmidt, Niehaus, & Nagel, 2006; Schmidt, Haberkamp, Veltkamp et al., 2011) as well as empirical background (cf. Schmidt, 2002). We show that information processing in fearful individuals is indeed enhanced for phobic images (i.e., spiders for spider-fearful participants; injuries for blood-injury-injection(BII)-fearful individuals). However, we found marked differences between the different types of phobia. In Experiment 1 and 2 (Chapter 2 and 3), spiders had a strong and specific influence in the group of spider-fearful individuals: Phobic primes entailed the largest priming effects, and phobic targets accelerated responses, both effects indicating speeded response activation by phobic images. In snake-fearful participants (Experiment 1, Chapter 2), this processing enhancement for phobic material was less pronounced and extended to both snake and spider images. In Experiment 3 (Chapter 4), we demonstrated that early information processing for pictures of small injuries is also enhanced in BII-fearful participants, even though BII fear is unique in that BII-fearful individuals show opposite physiological reactions when confronted with the phobic stimulus compared to individuals with animal phobias. These results show that already fast visuomotor responses are further enhanced in spider- and BII-fearful participants. Results give evidence that responses are based on the first feedforward sweep of neuronal activation proceeding through the visuomotor system. I propose that the additional enhancement in spider- and BII-fearful individuals depend on a specific hardwired binding of elementary features belonging to the phobic object in fearful individuals (i.e., effortless recognition of the respective phobic object via hardwired neuronal conjunctions). I suggest that these hardwired conjunctions developed due to long-term perceptual learning processes. We also investigate the frequently reported attentional bias of phobic individuals and showed that this bias is detectable in temporal order judgments using a prior entry paradigm. I assume that perceptual learning processes might also strengthen the attentional bias, for example, by providing a more salient bottom-up signal that draws attention involuntarily. In sum, I conclude that (1) early information processing of threatening stimuli is indeed enhanced in individuals with specific phobias but that (2) differences between divers types of phobia exist (i.e., spider- and BII-fearful participants show enhanced information of the respective phobic object; though, snake-fearful participants show no specific information processing enhancement of snakes); (3) the frequently reported attentional bias of spider-fearful individuals is also detectable in a prior entry paradigm.
Die vorliegende Arbeit beschreibt die Entwicklung eines Konzeptes und einer Online-Plattform für die Integration von onlinegestütztem Peer Feedback in Präsenzlehrangeboten an der Technischen Universität Kaiserslautern.
Feedback ist ein wichtiges Instrument im Lernprozess, insbesondere im aktiven Lernen, das für eine moderne Didaktik kennzeichnend ist. Außerdem ist Feedbackgeben eine zentrale Aufgabe des professionellen Handelns als Lehrer, so dass sich Peer Feedback Prozesse auf natürliche Art kompetenzentwickelnd in die Lehrerbildung einbetten lassen.
Auf Grundlage der existierenden Literatur wurde ein onlinegestützter Peer Feedback Prozess entworfen, implementiert, in verschiedenen Veranstaltungen umgesetzt und zugleich qualitativ beforscht. Die Forschung orientierte sich dabei an der Methodik der Design Based Research, die eine iterative Entwicklungsforschung in komplexen Strukturen ermöglicht und dabei Raum für den Umgang mit emergenten Phänomenen lässt, zugleich aber eine Generalisierung aus den konkreten Artefakten anstrebt.
Es stellt sich heraus, dass Peer Feedback mit der Online-Plattform PeerGynt eine wertvolle Ergänzung für Präsenzseminare ist: Durch einen dedizierten zeitlichen und organisatorischen Raum wird Feedback aufgewertet und hilfreicher für die Teilnehmenden.
In einer dreijährigen Längsschnittstudie wurde der Einfluss eines immersiven englischen Sprachangebots in der Kindertagesstätte auf die Entwicklung der englischen und deutschen Sprache bei 2- bis 6-jährigen Kindern untersucht. Darüber hinaus wurde geprüft, ob der bei bilingualen Personen nachgewiesene Vorteil in den exekutiven Kontrollfunktionen gegenüber monolingualen Personen auch bei Sprachimmersion repliziert werden kann und ob sich ein Vorteil in der phonologischen Bewusstheit durch Sprachimmersion ergibt. Dem Prinzip „Eine Person - eine Sprache“ folgend kommunizierte eine Erzieherin in der Immersionsgruppe ausschließlich in englischer Sprache mit den Kindern, während die anderen Erzieherinnen weiterhin deutsch sprachen. In der hinsichtlich Alter, Geschlecht und SES parallelisierten Kontrollgruppe fand einmal wöchentlich ein kindgerechter Englischunterricht statt. Einmal jährlich wurden verschiedene Tests zur Erfassung des sprachlichen Entwicklungsstands (Deutsch und Englisch; Sprachrezeption und Sprachproduktion), der exekutiven Kontrollfunktionen (inhibitorische Kontrolle: Day-Night-Task, Dimensional Change Card Sort Task, Fish-Flanker-Task) sowie ein Test zur Erfassung der phonologischen Bewusstheit durchgeführt. Die Kinder aus der Immersionsgruppe erreichten eine bessere englische rezeptive Sprachkompetenz als die Kinder der Kontrollgruppe. Es waren keine negativen Auswirkungen der englischen Sprachimmersion auf den Erwerb der deutschen Muttersprache nachweisbar. Die vergleichbaren Leistungen der Kinder in der Immersions- und Kontrollgruppe in den drei Aufgaben zur Erfassung der inhibitorischen Kontrolle und dem Test zur Erfassung der phonologischen Bewusstheit weisen darauf hin, dass keine positiven Effekte durch Sprachimmersion auf die Entwicklung der phonologischen Bewusstheit und der inhibitorischen Kontrolle erzielt werden konnten. Mögliche Ursachen für das Ausbleiben eines Vorteils durch Sprachimmersion im Bereich der exekutiven Kontrollfunktionen und der phonologischen Bewusstheit werden diskutiert.