Refine
Year of publication
Document Type
- Article (304)
- Doctoral Thesis (97)
- Preprint (49)
- Book (37)
- Contribution to a Periodical (17)
- Part of Periodical (15)
- Part of a Book (11)
- Conference Proceeding (9)
- Report (3)
- Review (3)
Is part of the Bibliography
- no (554)
Keywords
- fMRI (11)
- EEG (9)
- working memory (9)
- confirmatory factor analysis (7)
- episodic memory (7)
- ADHD (5)
- Behavior (5)
- Depression (5)
- aging (5)
- Functional connectivity (4)
Institute
- Psychologie (554) (remove)
Central and peripheral fields of view extract information of different quality and serve different roles during visual tasks. Past research has studied this dichotomy on-screen in conditions remote from natural situations where the scene would be omnidirectional and the entire field of view could be of use. In this study, we had participants looking for objects in simulated everyday rooms in virtual reality. By implementing a gaze-contingent protocol we masked central or peripheral vision (masks of 6 deg. of radius) during trials. We analyzed the impact of vision loss on visuo-motor variables related to fixation (duration) and saccades (amplitude and relative directions). An important novelty is that we segregated eye, head and the general gaze movements in our analyses. Additionally, we studied these measures after separating trials into two search phases (scanning and verification). Our results generally replicate past on-screen literature and teach about the role of eye and head movements. We showed that the scanning phase is dominated by short fixations and long saccades to explore, and the verification phase by long fixations and short saccades to analyze. One finding indicates that eye movements are strongly driven by visual stimulation, while head movements serve a higher behavioral goal of exploring omnidirectional scenes. Moreover, losing central vision has a smaller impact than reported on-screen, hinting at the importance of peripheral scene processing for visual search with an extended field of view. Our findings provide more information concerning how knowledge gathered on-screen may transfer to more natural conditions, and attest to the experimental usefulness of eye tracking in virtual reality.
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.
Soziale Phobie gilt als eine der am weitesten verbreiteten psychischen Störungen (Wittchen & Fehm, 2003; Magee et al., 1996). Obgleich zahlreiche Interventionsansätze zur Behandlung der sozialen Ängste zur Verfügung stehen, gibt es viele Betroffene, die nicht von den Behandlungsmöglichkeiten profitieren oder nach einer Therapie Rückfälle erleben. Aus diesem Grund beschäftigt sich die vorliegende Arbeit mit der Weiterentwicklung von Psychotherapie bei Sozialer Phobie. Sie greift verschiedene Forschungsperspektiven auf, um aktive Wirkfaktoren im therapeutischen Prozess zu identifizieren und für zukünftige Behandlungen nutzbar zu machen. Publikation 1 (Consbruch & Stangier, 2007) gibt einen Überblick über den aktuellen Forschungsstand bzgl. der Diagnostik, Ätiologie und Therapie bei Sozialer Phobie. Die in dieser Publikation dargestellten Forschungsarbeiten zur Behandlung sozialer Ängste vergleichen die therapeutische Wirksamkeit unterschiedlicher Therapieansätze und suchen so nach spezifischen Wirkfaktoren in der Behandlung Sozialer Phobien. Es zeigt sich, dass die kognitiv-verhaltenstherapeutische Behandlung am häufigsten untersucht wurde und dass sich ihre Effektivität durch die Berücksichtigung von Prozessen, die nach Clark und Wells (1995) an der Entstehung und Aufrechterhaltung der Sozialen Ängste beteiligt sind, erheblich verbessern lässt. Publikation 2 (Stangier, Consbruch, Schramm & Heidenreich, 2010) verlässt die ausschließlich an spezifischen Wirkmechanismen interessierte Forschungsperspektive und wendet sich der Frage nach dem Zusammenspiel von spezifischen und allgemeinen Wirkfaktoren zu. Sie vergleicht das Ausmaß der Aktivierung von allgemeinen Wirkfaktoren nach Grawe (1995) sowie deren Einfluss auf das Therapieergebnis in einer kognitiven Verhaltenstherapie (N=29) und einer interpersonellen Therapie (N=33). Die Ergebnisse zeigen, dass Therapeuten in der Interpersonellen Psychotherapie die Aktivierung von Bewältigung, Ressourcenorientierung und Motivationaler Klärung geringer einschätzten als Therapeuten in der kognitiven Verhaltenstherapie, während sie bezüglich der Problemaktivierung und der Güte der therapeutischen Beziehung keine Unterschiede angaben. Stärkere Ressourcenaktivierung stand in beiden Therapieansätzen mit besseren Therapieergebnissen in Beziehung, während höhere Problemaktualisierung nur in KVTBehandlungen zu verbessertem Outcome beitrug. Da die Ressourcenaktivierung in der KVTBedingung stärker ausgeprägt war als in der IPT-Bedingung, lassen sich die Ergebnisse so interpretieren, dass die Problemaktualisierung nur dann zu positiveren Therapieergebnissen führt, wenn sie durch ausreichende Ressourcenaktivierung gestützt wird. Die Studie legt somit nahe, dass spezifische Behandlungsansätze allgemeine Wirkfaktoren, die einen Einfluss auf das Therapieergebnis haben, in unterschiedlichem Maße nutzen. Durch das Fehlen von Angaben zur Therapieintegrität bleibt jedoch offen, welche Rolle individuelles Therapeutenverhalten bei der Aktivierung der allgemeinen und spezifischen Wirkfaktoren spielt. Um zukünftig die Therapieintegrität in der kognitiv-verhaltenstherapeutischen Behandlung von Sozialer Phobie sicherstellen zu können, wurde die Cognitive Therapy Competence Scale for Social Phobia (CTCS-SP) entwickelt, deren psychometrische Eigenschaften in Publikation 3 (Consbruch, Clark & Stangier, in press) dargestellt werden. Zur Bestimmung der Beobachterübereinstimmung wurden 161 Therapiesitzungen von jeweils 2 Ratern mit der CTCS-SP beurteilt. Die Ergebnisse der vorliegenden Untersuchung demonstrieren eine gute interne Konsistenz und gute Interraterreliabilität der Skala, wobei erstmals auch individuelle Items mit ausreichender Reliabilität gemessen werden konnten. Mit der CTCS-SP steht somit ein reliables Messinstrument zur Erfassung therapeutischer Kompetenz in der kognitivverhaltenstherapeutischen Behandlung der Sozialen Phobie zur Verfügung, welches – bei noch zu prüfender Validität - vielfältig eingesetzt werden kann, um die Erforschung
spezifischer und allgemeiner Wirkfaktoren in der kognitiv-verhaltenstherapeutischen Behandlung Sozialer Phobien zu vertiefen.
Background: Prolonged grief disorder (PGD) will be newly included in the ICD-11, while a clinically similar diagnosis, persistent complex bereavement disorder (PCBD), has already been added to the DSM-5. Only few studies have evaluated these criteria-sets for prolonged grief.
Objective: The aim of this study was to evaluate the ICD-11 accessory symptom threshold and compare the diagnostic performance of the two criteria-sets in treatment-seeking bereaved persons.
Method: 113 grief treatment-seeking bereaved persons completed the Interview for Prolonged Grief-13. We used receiver operator characteristic analysis to determine an optimum ICD-11 accessory symptom threshold. We calculated diagnostic rates for PGD and PCBD and examined associations of PGD and PCBD caseness with concurrently assessed psychopathology and prolonged grief symptoms assessed one month later.
Results: An ICD-11 threshold of six accessory symptoms distinguished optimally between interview-diagnosed participants with and without prolonged grief. The prevalence of PGD (69%) was significantly higher than that of PCBD (48%) and of PGD with a 6-symptom threshold (47%). PGD caseness was associated with the relation to the deceased, 6-symptom threshold PGD and PCBD caseness with the time since loss. All criteria-sets were linked to concurrent prolonged grief, depression, and general mental distress. PCBD and 6-symptom threshold PGD but not PGD were associated with prolonged grief severity one month later.
Conclusions: The results support the validity of PGD and PCBD but, at the same time, they provide further support for differing prevalence rates. Using an empirically determined ICD-11 accessory symptom threshold could prevent the pathologisation of grief reactions.
Orientation: Publishing methodologically sound, empirically based studies in reputable accredited scientific journals are essential in order to advance knowledge and evidence-based practice in the field of industrial and organisational psychology.
Research purpose: The purpose of the research was to conduct a broad content analysis of the articles published in the South African Journal of Industrial Psychology (SAJIP) between 2004 and 2013. The study aimed to provide a descriptive overview of the most frequent content themes,published authors and institutions, research approaches, strategies, designs and analysis techniques, software packages and sample sizes in industrial and organisational (I-O) psychology utilised in the publications.
Motivation for study: The periodic analyses of published content in scholarly journals provide an index of the extent to which the publications reflect the scope of practice in a given discipline and broaden insight into the direction and relevance of research published in a journal.
Research design, approach and method: A broad systematic content analysis was conducted of 342 documented articles published in the SAJIP between 2004 and 2013. Descriptive data(frequencies and percentages) were used to report the findings.
Main findings: The publishing pattern of the SAJIP appeared to correspond with its focus and scope. Manuscripts utilising mostly cross-sectional quantitative correlational research designs with large samples (n > 201) were published in the SAJIP. The University of Johannesburg and Professor Sebastiaan (Ian) Rothmann were the largest contributors to publications between 2004 and 2013. Organisational psychology and psychometrics were the most prominent domains in I-O psychology research. Data were predominantly processed utilising SPSS.
Practical implications: The insights derived from the findings can be employed to plan future research initiatives in the field of I-O psychology.
Contribution/value-add: The findings provide valuable insight into the current status of the foci of I-O psychology research as published in the SAJIP between 2004 and 2013 and the contribution made by the SAJIP to advancing knowledge and evidence-based practice in I-O psychology.
South African Journal of Industrial and Organisational Psychology: Annual editorial overview 2015
(2015)
Background: While the efficacy of cognitive therapy (CT) has been well established for social anxiety disorder (SAD) in several randomized controlled trials, there are still large differences between trials with respect to effect sizes. The present study investigates the question of whether enhanced training and the use of behavioral experiments (BEs) increases the efficacy of traditional CT, based on verbal methods of cognitive restructuring. Methods/design: A mixed within/between conditions design will be applied, with therapists and patients being randomly allocated to one of two conditions: (1) training of CT plus BEs, (2) training of CT “as usual”. Sixty patients with the primary diagnosis of SAD will be recruited and treated in the outpatient clinic of the Department of Psychology, University of Frankfurt. To ensure adherence to therapist protocols, all therapists will be trained and supervised by the project coordinators. In addition, videotaped treatment sessions will be independently evaluated to guarantee both adherence to protocols and the quality of the intervention. Treatment effects will be assessed by independent SAD symptom ratings using the Liebowitz Social Anxiety Scale as the primary outcome measure and self-report measures as secondary outcome measures. Discussion: The present cognitive behavioral therapy (CBT) trial will be the first to clarify the contribution of BEs to the efficacy of CT in a randomized controlled design. Study results are relevant to clinical training and implementation of evidence-based treatments. Trial registration: German Clinical Trials Register International Clinical Trials Registry Platform (ICTRP) identifier: DRKS00014349. Trial status: recruiting.
Von April bis Juli 2012 fand der sogenannte OPCO12 statt, der offene (open) Online Course 2012. Inhaltlich befasste sich dieser MOOC (Massive Open Online Course) mit „Trends im E-Teaching“. Zum Zeitpunkt der Planung des OPCO12 stand das MOOC-Format im deutschsprachigen Kontext noch ganz am Anfang und dadurch im Erprobungs- und Experimentierstadium, was auch Einfluss auf die Themenwahl hatte: Um eine gewisse Teilnehmerzahl zu sichern und die Bekanntmachung des Kurses bei medienaffinen Teilnehmenden zu erleichtern, wurde – ähnlich wie in der Anfangsphase von MOOCs im nordamerikanischen Raum – für den OPCO12 ein eher selbstreferenzielles Thema gewählt, d.h. der Kurs behandelte die Themen Medien und Bildung. Im vorliegenden Beitrag befassen sich die Autorinnen vor allem mit der Frage, welche Schlussfolgerungen aus den Erfahrungen mit dem OPCO12 gezogen werden können. Nach einer Einordnung des Kurses in die (deutschsprachige) MOOC-Landschaft (Abschnitt 1) und einer Darstellung der zugrunde liegenden konzeptionellen Überlegungen (Abschnitt 2) werden ausgewählte Evaluationsergebnisse vorgestellt, darunter auch motivationale Faktoren (Abschnitt 3). Der Beitrag schließt mit einem perspektivischen Fazit (Abschnitt 4).