Symposia at ECVP 2008

There are four special symposia in this year's program:

1. Marburg +30 (top)
The original Marburg meeting (the “Workshop on sensory and perceptual processes”), jointly organised by the Tagung Experimentell Arbeitender Psychologen (Lothar Spillmann) and the Experimental Psychology Society (John Mollon) included disparate topics such as spatial vision, visual form perception, eye-movements and colour perception. These topics are still important topics in the field. Four of the original participants to the meeting return to the topic they presented 30 years ago, and discuss the advances that have occurred over the intervening 30 years. This Symposium is sponsored by the Nederlandse Vereniging voor Psychonomie (NVP).

2. Constructing the visual world (top)
Normally we perceive the world as unambiguous and stable. However, sometimes our conscious percept is unstable, switching between two or more interpretations. This is the case when we observe an ambiguous figure, like the Necker cube, or when each of our eyes receives a different image, resulting in binocular rivalry. The phenomenon of perceptual instability is present in every neuroscience textbook and is regarded as key tool for investigating conscious perception, because stimulus-related neural activity may be separated experimentally from perception-related activity. The major debate is whether visual ambiguity is resolved by top-down or by bottom-up mechanisms. This reflects the question of whether visual information is generally ambiguous, requiring interpretation and reconstruction, or whether it is generally complete, with instability phenomena being contrivances in an otherwise unambiguous world.
The speakers in the symposium will bring together different positions and review new physiological, electrophysiological, and psychophysical evidence of when, where, and how we resolve visual ambiguity. They will attempt to reach a consensus about the underlying neural mechanisms and discuss the relevance of these phenomena for consciousness and cognition.

3. Synaesthesia (top)
This symposium provides a cross-cutting snapshot of synaesthesia research, with a focus on its neural origins, its impact on visual attention, and its implications for the development and plasticity of crossmodal processing in normal cognition. The overview talk will provide a basic introduction of research on synaesthesia and crossmodal perception, with an aim at connecting the various research themes under a common framework. A particular focus will be paid to the implications that synaesthesia and crossmodal perception have for visual perception, and for possible visual aids for the blind. The four talks will focus on aspects of synaesthesia research described above, providing an excellent basis for a discussion of particular intersecting areas of research on crossmodal perception and vision.

4. Crowding (top)
In the periphery, a visual object that is easily recognized when shown in isolation is hard to identify when surrounded by other objects. This is "crowding". Diverse studies of crowding come together to reveal one universal story, the "Bouma Law": to be identified, simple objects must be separated by at least the observer's critical spacing -- as reported in the pioneering work of Herman Bouma in the 1970's. Recent work confirms Bouma's claim that crowding severely limits the rates of reading and visual search. While the phenomenon of crowding has been well described, theoretical understanding of it is still tentative. For instance, it has been suggested that crowding may be feature integration for object recognition, or compulsory averaging for texture perception. This is an honorary symposium, but it presents a major controversy, evenly split, for and against the Bouma law. The first talks will support the Bouma law. the other talks challenge the Bouma Law by revealing new findings under which it apparently fails.