28th International Congress of Psychology August 8 ... - U-netSURF

understanding. Cognitive universals, as discovered in Piaget’s work, lead us to deep and general
mental structures that are not influenced by education. Mental organizations that allow the
solution to specific problems, such as ratio comparisons in pan balance scales as studied by
Siegler’s rule assessment procedure, lead us to mental organizations that have very little generality,
but they can be influenced by education. Middle level cognitive organizations have some
generality and can be influenced by education. Finding them should be a goal of research,
teaching and curriculum and development.
2039 INVITED SYMPOSIUM
Neo-gestalt contributions to the understanding of perceptual organization
Convener and Chair: J. Wagemans, Belgium
2039.1 Past experience and competition in figure assignment, M.A. Peterson, University of
Arizona, Tucson, AZ, USA
An assumption that long served as a foundation for research in visual perception and cognition is
that figure-ground segregation precedes access to shape memories, including traces of configured
portions of shapes. Contrary to this assumption, experiments measuring perception both implicitly
and explicitly show that past experience with particular shapes is among the cues that determine
figure assignment, and that these effects can be evident following a single exposure to a novel
shape. These results are best understood within a competitive model in which past experience is
expressed for portions of configured edges.
2039.2 Neural mechanisms of perceptual organization in humans, S.H. Han, Peking University,
Beijing, China
We investigated when and where perceptual organization occurs in human brains and whether the
neural substrates underlying perceptual organization are modulated by task relevance and attention.
Subjects identified orientations of perceptual groups formed by proximity or similarity of local
elements or identified colors of dots at fixation or in the visual field. Using ERPs and fMRI neural
substrates of perceptual organization of local elements were localized within the calcarine cortex
as early as 80 ms after stimulus onset; the neural correlates were weakened when the elements
were of low task relevance and fell outside an attended area of field.
2039.3 Can the gestalt rules be replaced by a single rule of adjacency? R.J. Watt, Stirling
University, Scotland, UK
The Gestalt rules of vision describe those circumstances where distinct elements in the visual field
will be perceived as belonging together. It is proposed that the various rules are equivalent to
adjacency within a visual topology defined by the intera
2039.4 Visual computations and visual cortex, S.W. Zucker, Yale University, New Haven, CT,
USA
A computational abstraction for visual cortex is developed in which the clustered, long-range
horizontal connections provide a substrate for early perceptual integration. We introduce a model
of orientation continuation based on differential geometry to formalize the intuitions behind
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