- •CONTENTS
- •PREFACE
- •Abstract
- •1. Introduction
- •2.1. Differential Geometry of Space Curves
- •2.2. Inverse Problem Formulation
- •2.3. Reconstruction of Unique Space Curves
- •3. Rigid Motion Estimation by Tracking the Space Curves
- •4. Motion Estimation Using Double Stereo Rigs
- •4.1. Single Stereo Rig
- •4.2. Double Stereo Rigs
- •5.1. Space-Time or Virtual Camera Generation
- •5.2. Visual Hull Reconstruction from Silhouettes of Multiple Views
- •5.2.1. Volume Based Visual Hull
- •5.2.1.1. Intersection Test in Octree Cubes
- •5.2.1.2. Synthetic Model Results
- •5.2.2. Edge Base Visual Hull
- •5.2.2.1. Synthetic Model Results
- •Implementation and Exprimental Results
- •Conclusions
- •Acknowledgment
- •References
- •Abstract
- •Introduction: Ocular Dominance
- •Demography of Ocular Dominance
- •A Taxonomy of Ocular Dominance
- •Is Ocular Dominance Test Specific?
- •I. Tests of Rivalry
- •II. Tests of Asymmetry
- •III. Sighting Tests
- •Some Misconceptions
- •Resolving the Paradox of Ocular Dominance
- •Some Clinical Implications of Ocular Dominance
- •Conclusion
- •References
- •Abstract
- •1. Introduction
- •2. Basic Teory
- •3. Bezier Networks for Surface Contouring
- •4. Parameter of the Vision System
- •5. Experimental Results
- •Conclusions
- •References
- •Abstract
- •Introduction
- •Terminology (Definitions)
- •Clinical Assessment
- •Examination Techniques: Motility
- •Ocular Motility Recordings
- •Semiautomatic Analysis of Eye Movement Recordings
- •Slow Eye Movements in Congenital Nystagmus
- •Conclusion
- •References
- •EVOLUTION OF COMPUTER VISION SYSTEMS
- •Abstract
- •Introduction
- •Present-Day Level of CVS Development
- •Full-Scale Universal CVS
- •Integration of CVS and AI Control System
- •Conclusion
- •References
- •Introduction
- •1. Advantages of Binocular Vision
- •2. Foundations of Binocular Vision
- •3. Stereopsis as the Highest Level of Binocular Vision
- •4. Binocular Viewing Conditions on Pupil Near Responses
- •5. Development of Binocular Vision
- •Conclusion
- •References
- •Abstract
- •Introduction
- •Methods
- •Results
- •Discussion
- •Conclusion
- •References
- •Abstract
- •1. Preferential Processing of Emotional Stimuli
- •1.1. Two Pathways for the Processing of Emotional Stimuli
- •1.2. Intensive Processing of Negative Valence or of Arousal?
- •2. "Blind" in One Eye: Binocular Rivalry
- •2.1. What Helmholtz Knew Already
- •2.3. Possible Influences from Non-visual Neuronal Circuits
- •3.1. Significance and Predominance
- •3.2. Emotional Discrepancy and Binocular Rivalry
- •4. Binocular Rivalry Experiments at Our Lab
- •4.1. Predominance of Emotional Scenes
- •4.1.1. Possible Confounds
- •4.2. Dominance of Emotional Facial Expressions
- •4.3. Inter-Individual Differences: Phobic Stimuli
- •4.4. Controlling for Physical Properties of Stimuli
- •4.5. Validation of Self-report
- •4.6. Summary
- •References
- •Abstract
- •1. Introduction
- •2. Algorithm Overview
- •3. Road Surface Estimation
- •3.1. 3D Data Point Projection and Cell Selection
- •3.2. Road Plane Fitting
- •3.2.1. Dominant 2D Straight Line Parametrisation
- •3.2.2. Road Plane Parametrisation
- •4. Road Scanning
- •5. Candidate Filtering
- •6. Experimental Results
- •7. Conclusions
- •Acknowledgements
- •References
- •DEVELOPMENT OF SACCADE CONTROL
- •Abstract
- •1. Introduction
- •2. Fixation and Fixation Stability
- •2.1. Monocular Instability
- •2.2. Binocular Instability
- •2.3. Eye Dominance in Binocular Instability
- •3. Development of Saccade Control
- •3.1. The Optomotor Cycle and the Components of Saccade Control
- •3.4. Antisaccades: Voluntary Saccade Control
- •3.5. The Age Curves of Saccade Control
- •3.6. Left – Right Asymmetries
- •3.7. Correlations and Independence
- •References
- •OCULAR DOMINANCE
- •INDEX
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Georg W. Alpers and Antje B.M. Gerdes |
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Taken together, there is some evidence that emotional meaning influences binocular rivalry, but until now, only few studies investigated this influence systematically.
4. Binocular Rivalry Experiments at Our Lab
4.1. Predominance of Emotional Scenes
We argue that binocular rivalry provides for very interesting experiments in emotion research, but our review of the literature demonstrated that this question has not been thoroughly investigated. There is a general lack of recent and methodically convincing studies. The first study on binocular rivalry from our lab investigated whether complex emotional pictures predominate over neutral pictures (Alpers and Pauli, 2006). Sixty-four healthy participants were stereoscopically shown ten pairs of pictures from the International Affective Picture System (IAPS, Lang, Bradley, and Cuthbert, 2005). These pictures depict different emotional scenes and are frequently used as stimuli in emotion research. Using this widespread picture material allows for a direct comparison of the results with data from other established paradigms.
Because positive as well as negative pictures elicit similar patterns of activation in areas responsible for emotional processing (see above), we chose pictures of negative, neutral and positive valence for this study. If pictures with emotionally activating content predominated over neutral pictures in binocular rivalry, this would suggest that emotional input is preferentially processed at an early stage of visual processing. Thus, pairs of pictures were composed with one emotional (positive or negative) and one neutral picture each. These pairs were presented for 30 sec in a randomized order. Participants looked through a mirror stereoscope that was mounted about 30 cm in front of the computer monitor. Thus only one picture was projected to each eye. In contrast to earlier studies, participants had to continuously verbalize what their perceptual impression was throughout each trial.
Participants were not explicitly instructed to categorize emotional and neutral percepts, but were simply asked to report the content they saw. A trained research assistant coded the participants’ comments as emotional or neutral with button presses. A ratio of the cumulative time for emotional versus neutral percepts was used as the dominance index. We assessed the initial perceptual impression in each trial as another dependent variable because this is thought to be less strongly affected by habituation and less error-prone with regard to verbalization.
Temporarily Blind in One Eye |
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First of all, our results confirmed that emotional pictures are considerably longer perceived as dominant than neutral pictures. Also, the initial perceptual impression was significantly more often that of the emotional as opposed to the neutral picture. Differences in predominance were not found between positive and negative pictures, either in duration of the percept nor in the frequency of the initial percept. This experiment clearly shows that pictures of emotional scenes presented to one eye predominate over neutral pictures presented to the other eye. This confirms our hypothesis that emotional content can boost visual perception.
As clear cut as the results of this experiment may be, a number of serious limitations have to be considered. First, verbal coding is certainly prone to response biases. The tendency to more often mention emotional picture contents could have had an influence on the results, as well as a tendency to avoid verbalizing specific picture content, because some contents may have been embarrassing for the participant, for example (erotic pictures). Verbalizing unpleasant issues (repellent and disgusting details) could also pose a problem. Furthermore, relatively large pictures were used in this study, and this often leads to the perception of mixed pictures, so called piecemeal rivalry (O'Shea, Sims, and Govan, 1997). Although it was also possible to report mixed pictures, it remains unclear whether participants applied different decision criteria for reporting mixed or unambiguous percepts.
In conclusion, these results support the hypothesis that binocular rivalry is influenced by the emotional contents of two competing pictures.
4.1.1. Possible Confounds
Among the undesirable confounding factors which can potentially influence perceptual dominance, potential physical differences in the pictures’ complexity and color are certainly most important. However, to a large extent such differences are closely associated with the emotional content (Lang et al., 1998).
Binocular rivalry is strongly influenced by certain physical characteristics. For example, larger pictures tend to fuse with each other more strongly than smaller pictures (i.e. the rate at which rivalry occurs, is diminished) (O'Shea, et al., 1997). Pictures with high-contrast are perceived more dominantly compared with low-contrasted pictures (Blake, 1989). Brighter pictures dominate more frequently than darker pictures (Kaplan and Metlay, 1964) and moving pictures dominate over stable pictures (Blake and Logothetis, 2002). The studies summarized below are aimed at controlling for physical characteristics and at controlling for possible problems with self report.